tag:blogger.com,1999:blog-42599706049411606652024-03-15T06:39:49.468-07:00Am I An Engineer?A question which every engineer asked himself when he was burning the midnight oil while his manager chased for resultsAnonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.comBlogger28125tag:blogger.com,1999:blog-4259970604941160665.post-420511812623985262015-01-23T20:41:00.001-08:002015-01-23T20:41:56.265-08:00Electrical Conductivity and Resistivity<div style="text-align: justify;">
I guess “conductivity” and “resistivity” are terms relatively simple to explain to the general public. Conductive materials conduct electrical currents easily, and resistive materials resist electrical currents. So what should an engineer know about these terms that the general public does not generally know? By knowing how they are defined, and knowing the difference between resistivity and conductivity, and resistance and conductance.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-AzVmJoMShDo/VMMhz4NFCKI/AAAAAAAAAb4/IbsLDZhhTu0/s1600/lost.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://1.bp.blogspot.com/-AzVmJoMShDo/VMMhz4NFCKI/AAAAAAAAAb4/IbsLDZhhTu0/s1600/lost.jpg" height="480" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>No, this is not about "Resistance: Fall of Man" game (image taken from <a href="http://bestgamewallpapers.com/resistance-fall-of-man/lost">Best Game Wallpapers</a>).</i></span></td></tr>
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<a name='more'></a><b>Definition</b></div>
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<blockquote class="tr_bq">
Terminology: <b><span style="color: orange;">Electrical Resistivity</span></b>; <b><span style="color: orange;">Resistivity</span></b>; <b><span style="color: orange;">Specific Electrical Resistance</span></b>; <b><span style="color: orange;">Volume Resistivity</span></b><br />
Definition: <u>a material’s intrinsic ability to oppose electrical current flowing through it</u><br />
Symbol: ρ<br />
S.I. Unit: ohm⋅meter (Ω⋅m)</blockquote>
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<blockquote class="tr_bq">
Terminology: <b><span style="color: orange;">Electrical Conductivity</span></b>; <b><span style="color: orange;">Specific Conductance</span></b><br />
Definition: <u>a material’s intrinsic ability to conduct electrical current through it</u><br />
Symbol: σ (occasionally κ and γ)<br />
S.I. Unit: siemens per meter (S/m)</blockquote>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td><a href="http://1.bp.blogspot.com/-JJtIB6GAIQU/VMMdXgParqI/AAAAAAAAAbI/M4Mp1lYlvms/s1600/515c7a2bce395f653d000002.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://1.bp.blogspot.com/-JJtIB6GAIQU/VMMdXgParqI/AAAAAAAAAbI/M4Mp1lYlvms/s1600/515c7a2bce395f653d000002.png" height="494" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="font-size: 13px;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>The universal understanding about resistance in an image... (image taken from <a href="https://learn.sparkfun.com/tutorials/resistors">Sparkfun</a>).</i></span></td></tr>
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Most resistors and conductors are made of a single material (instead of a composite) and have uniform cross section with a uniform flow of electrical current (think copper wires). The <b><span style="color: orange;">electrical resistivity</span></b> is defined as:</div>
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<img src="file:///C:/Users/konshoe/AppData/Local/Temp/msohtmlclip1/01/clip_image002.gif" /></div>
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<a href="http://1.bp.blogspot.com/-wlANKN5J_KA/VMEnFBWsbzI/AAAAAAAAAaU/FZYG6Uy57pA/s1600/resistivity.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://1.bp.blogspot.com/-wlANKN5J_KA/VMEnFBWsbzI/AAAAAAAAAaU/FZYG6Uy57pA/s1600/resistivity.JPG" /></a></div>
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<blockquote class="tr_bq">
<i>R = electrical resistance of a uniform cross section material; unit is ohm (Ω)<br />A = cross section area of the material; unit is square meters (m2)<br />l = length of material; unit is meters (m)</i></blockquote>
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<b><span style="color: orange;">Resistance</span></b> is then found through:</div>
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<a href="http://4.bp.blogspot.com/-o59Thi2vJIA/VMEnFP9LOdI/AAAAAAAAAag/lnu-Q7gX3J0/s1600/resistance.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://4.bp.blogspot.com/-o59Thi2vJIA/VMEnFP9LOdI/AAAAAAAAAag/lnu-Q7gX3J0/s1600/resistance.JPG" /></a></div>
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<b><span style="color: orange;">Conductivity</span></b> is calculated as <u>the inverse of resistivity</u>:</div>
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<a href="http://2.bp.blogspot.com/-YIydPIVjD1g/VMEnFJqUbjI/AAAAAAAAAac/hOB5pMrIor4/s1600/conductivity.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://2.bp.blogspot.com/-YIydPIVjD1g/VMEnFJqUbjI/AAAAAAAAAac/hOB5pMrIor4/s1600/conductivity.JPG" /></a></div>
<img src="file:///C:/Users/konshoe/AppData/Local/Temp/msohtmlclip1/01/clip_image006.gif" /></div>
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As an engineer, it is imperative to understand that “resistance” and “resistivity” are different terms. <u>Resistivity is an intrinsic material property</u>, just like Young’s modulus, and is independent on the material geometry. <u>“Resistance” however is a geometrical property.</u> The resistivity of a pure copper wire is always constant (1.68×10−8 Ω⋅m) because this is pure copper’s property, but the wire’s resistance between both ends is higher when the wire gets longer. The same understanding should be applied to both “conductance” and “conductivity”.</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-NGB7jXZ_5Sw/VMMenz0cEmI/AAAAAAAAAbc/F8G-CjNlx-c/s1600/graphene-onSubstrate-3Dmodel.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://3.bp.blogspot.com/-NGB7jXZ_5Sw/VMMenz0cEmI/AAAAAAAAAbc/F8G-CjNlx-c/s1600/graphene-onSubstrate-3Dmodel.jpg" height="426" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>3D rendering of a graphene sheet, a material with the lowest resistivity to date (image taken from <a href="http://www.jameshedberg.com/scienceGraphics.php?sort=graphene&id=graphene-onSubstrate-3Dmodel">James Hedberg</a>).</i></span></td></tr>
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<b>Interesting facts</b></div>
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As engineers, we should be aware of some material facts related to resistivity less we become laughing stocks. Here are some interesting facts that some engineers may miss, especially if their job need not deal too much with this property.</div>
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<ul>
<li>Resistivity of a material is <u>temperature dependant</u>, so generally the value is listed in room temperature of 20°C. An increase in temperature will generally see the resistivity increase in metals and decrease in semiconductors.</li>
</ul>
<ul>
<li>Among the 3 precious metals most used in electrical conductors, Silver (1.59×10−8 Ω⋅m) has the lowest resistivity compared to Copper (1.68×10−8 Ω⋅m) and Gold (2.44×10−8 Ω⋅m). The reason it is used less extensively is because Copper is cheaper and Gold is more corrosion resistant.</li>
</ul>
<ul>
<li><b><span style="color: orange;">Semiconductors</span></b> and <b><span style="color: orange;">electrolytes</span></b> (solution of water) have variable resistivity; the former is dependent on a large variety of factors while the latter is dependent on the concentration of dissolved salts.</li>
</ul>
<ul>
<li><b><span style="color: orange;">Superconductors</span></b> have the ideal resistivity of 0.</li>
</ul>
<ul>
<li>Carbon in the form of graphite has lower resistivity (2.5 – 5.0×10−6 Ω⋅m parallel to basal plane) than in diamond form (1×1012 Ω⋅m), showing how the same element could have different resistivity in different form. However diamond is still more conductive than air (1.30 – 3.30×1016 Ω⋅m).</li>
</ul>
<ul>
<li>The material with the lowest resistivity in room temperature is graphene (1.00×10−8 Ω⋅m), which is pure carbon in sheet form as thick as an atom.</li>
</ul>
</blockquote>
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<tr><td style="text-align: center;"><div style="text-align: left;">
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<a href="http://2.bp.blogspot.com/-TxXw_WONeVc/VMMfhulILrI/AAAAAAAAAbk/On4J1exbkr0/s1600/superconductormain.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://2.bp.blogspot.com/-TxXw_WONeVc/VMMfhulILrI/AAAAAAAAAbk/On4J1exbkr0/s1600/superconductormain.jpg" height="480" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>A piece of magnet levitating above a superconductor. Superconductors work at very low temperatures and have a resistivity of 0 (image taken from <a href="http://www.newscientist.com/special/instant-expert-superconductors">New Scientists</a>).</i></span></td></tr>
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A very useful comparison of the resistivity and conductivity of most materials could be viewed from <a href="http://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity">Wikipedia</a> (where else).<br />
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Sources:<br />
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<ol>
<li><a href="http://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity">Wikipedia - Electrical Resistivity and Conductivity</a></li>
<li><a href="http://www.azom.com/news.aspx?newsID=11679">AZO Materials - Graphene - The Best Electrical Conductor Known to Man</a></li>
</ol>
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Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com1tag:blogger.com,1999:blog-4259970604941160665.post-39102328430374963032015-01-22T07:48:00.001-08:002015-01-27T01:12:56.837-08:00Metal whiskering<div dir="ltr" style="text-align: left;" trbidi="on">
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Do you know that not only mice and felines grow whiskers? Metals do too! Surprise surprise! To system and electronic engineers however this is an unpleasant surprise, a nightmare that they wish never will happen in their products. This phenomenon gain so much attention that high tech companies such as Lockheed Martin and NASA are still trying to understand it.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-PVsQWeqwqNE/VMEJ1ziht6I/AAAAAAAAAYw/NptGF8pLKtk/s1600/TinWhiskers460x276.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://1.bp.blogspot.com/-PVsQWeqwqNE/VMEJ1ziht6I/AAAAAAAAAYw/NptGF8pLKtk/s1600/TinWhiskers460x276.jpg" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>The removal of lead from solders increases the chances of tin whisker occurring. The phenomenon of whiskering had caused multimillion havocs, including the false alarm of Millstone nuclear plant, Swatch watches recall and the lost of Galaxy IV satellite (image taken from <a href="http://www.theguardian.com/technology/2008/apr/03/research.engineering">The Guardian</a>).</i></span></td></tr>
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<a name='more'></a><b>What is metal whiskering?</b></div>
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Just as the name suggests, <b><span style="color: orange;">metal whiskering</span></b> appears as thin strands growing out of a metal product like a whisker. According to Wikipedia, it is a “<u>crystalline metallurgical phenomenon involving the spontaneous growth of tiny, filiform hairs from a metallic surface</u>”. It is primarily observed occurring in <u>elemental metals </u>(read “close to pure” metals), but also noted in certain cases to be alloys.</div>
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The most commonly encountered phenomenon is <b><span style="color: orange;">tin whiskers</span></b> growing out of tin solders in electronic products. Zinc whiskers are also common in galvanized metals, and even silver and gold whiskers are encountered in some cases.</div>
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The mechanism behind the growth of whiskers is not well understood, and although it is generally suspected that <u>it is encouraged by compressive mechanical stresses</u>, there is no real understanding why that could create the strands. A few situations promoting such growth could be:</div>
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<ul>
<li><i>residual stresses from electroplating</i></li>
<li><i>mechanically-induced stresses</i></li>
<li><i>stresses induced by diffusion of different metals</i></li>
<li><i>thermally induced stresses</i></li>
<li><i>strain gradients in materials</i></li>
</ul>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-U6di-6upaw8/VMEK7jdvaTI/AAAAAAAAAZU/xA4LCoVOKi4/s1600/whiskersfig1.gif" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://1.bp.blogspot.com/-U6di-6upaw8/VMEK7jdvaTI/AAAAAAAAAZU/xA4LCoVOKi4/s1600/whiskersfig1.gif" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-family: Georgia, Times New Roman, serif; font-size: small;"><i><br /><span style="color: cyan;">Tin whiskers growing on tin plated connectors (image taken from <a href="http://www.empf.org/empfasis/july05/whiskers705.htm">Empfasis</a>).</span></i></span></td></tr>
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To illustrate an example of whiskering due to compressive mechanical stress, one frequently encountered phenomenon is system failures in computer server rooms. Zinc whiskers grow from galvanized (which is zinc plated) metal surfaces, such as the underside of raised galvanized floor tiles, at up to 1mm per year. Their growth is thought to be formed from mechanical stresses induced when they are walked upon. When the tiles are disturbed, the whiskers became airborne, and due to their miniature sizes they managed to bypass air filters and settle within equipment, finally shorting out the circuitry and creating system failures.</div>
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One <a href="http://www.insidescience.org/content/new-theory-explains-mysterious-growth-metal-strands/1642">recent publishing in “Physical Review Applied”</a> by a Victor Karpov from University of Toledo in Ohio may suggest an alternative theory to explain why the growth happen. In Karpov’s paper, he suggested that the strands grew out not directly due to mechanical stress but from electric fields generated by the metal itself.</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-yZRyMMEabCk/VMENgr5S2-I/AAAAAAAAAZ8/MdYnhK3dltg/s1600/tin%2Bwhiskers%2Bcardguide_opt.jpeg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://1.bp.blogspot.com/-yZRyMMEabCk/VMENgr5S2-I/AAAAAAAAAZ8/MdYnhK3dltg/s1600/tin%2Bwhiskers%2Bcardguide_opt.jpeg" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>Tin whiskers growing from tin-plated card guides. It can be seen from this image how tiny the strands are and that they have no problem bridging long distance relative to their size (image taken from <a href="http://www.micromanufacturing.com/content/growing-problem-unclipped-%E2%80%98tin-whiskers%E2%80%99-can-short-circuit-electronic-devices">Unclipped</a>, originally from NASA Electronic Parts and Packaging Program).</i></span></td></tr>
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In this theory, stress or irregularities on the metal surface could create areas of positive and negative electrical charges. Each of these charged areas could generate an electrical field that repels particles of the same charge. Particles of metal of the same charge on the surface will be repelled this way, shooting away from the surface and forming a strand that grows as more particles are expelled.</div>
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Although the theory is under verification, it helps explain the role played by stress and contaminants in whisker growth. Another effect the theory may help shed light on is the fact that whisker grows out slowly but sprout quickly after a month or so.</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-qkizvCFpVYc/VMEK-iIi8II/AAAAAAAAAZY/dRyZNFlt98o/s1600/1379602609870.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://2.bp.blogspot.com/-qkizvCFpVYc/VMEK-iIi8II/AAAAAAAAAZY/dRyZNFlt98o/s1600/1379602609870.jpg" height="291" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>Microscopic view of tin whiskers (image taken from <a href="http://www.lockheedmartin.com/us/news/features/2013/tin-whiskers.html">Lockheed Martin</a>).</i></span></td></tr>
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<b>Effects</b></div>
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Due to miniaturization, components and circuit lines are placed as close to each other as processes allowed, so when tin whiskers grow out of them, they could potentially touch the other conducting element, be it a component or a circuit line, thus <u>shorting the circuit</u>.</div>
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Even if they do not touch each other, tin whiskers could still <u>promote arcing</u>. The minimum recommended spacing between circuit lines and components usually takes into consideration the possibility of electric charges discharging through air or non-conductive materials, thus still shorting the circuit without any conductive contact. With the propagation of tin whiskers over circuit board, this distance is minimized further, causing unintended effects.</div>
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Short circuit is not the only problem caused by tin whiskers. In <u>high speed circuitry and in frequency applications above 6 GHz, the thin strands act as miniature antennas</u> which could cause reflections and affect circuitry impedance. The strands can also <u>break off in certain cases and cause mechanical failures in miniature products</u>, such as bearing failures in computer disks. </div>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-c1--5B_D5lA/VMEMP3DprXI/AAAAAAAAAZw/t1vp9u693Hc/s1600/galaxy-4__1.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://1.bp.blogspot.com/-c1--5B_D5lA/VMEMP3DprXI/AAAAAAAAAZw/t1vp9u693Hc/s1600/galaxy-4__1.jpg" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>The Galaxy IV communication satellite was announced lost in 1998 due to tin whisker formation which shorted the main control computer. The satellite is still orbiting in space to date (image taken from <a href="http://space.skyrocket.de/doc_sdat/galaxy-4.htm">Gunter's Space Page</a>).</i></span></td></tr>
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<b>History and Famous Failures</b></div>
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The history of metal whiskers is relatively old, with the first discovery occurring back in the 1940s by telephone companies. Cadmium, being the primary choice for electroplating electrical components at that era, was discovered to grow whiskers and caused shorting and system failures in electrical products. Similar problem was discovered when pure tin was used as replacement. Bell Laboratories initiated a long term research into the phenomenon along with several large organizations, culminating in much of the subsequent knowledge and establishing whisker mitigation practices that are still in use to date.</div>
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One of the most famous, and most costly, failure is the lost of Galaxy IV communication satellite in 1998. Its lost was attributed to the formation of tin whiskers, which broke through the conformal coating, shorted the circuitry and caused the failure of the main control computer. The manufacturer, Hughes, changed the plating to nickel to mitigate this problem, adding the payload weight.</div>
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A less dramatic but still attention catching event was the false alarm of Millstone Nuclear Power Plant in Connecticut. In April 2005, the plant detected an unsafe level of pressure drop in the reactor’s steam system, prompting a shutdown. Investigations revealed that the pressure level was nominal, and the alert was due to a short circuit in the steam pressure line monitor’s circuit board, which cause was attributed to a tin whisker.<br />
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The interested engineer is highly recommended to go to the following sources, especially the <a href="http://nepp.nasa.gov/Whisker/background/index.htm">NASA webpage</a>, for a more comprehensive understanding of the whiskering phenomenon.</div>
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Sources:</div>
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<li><a href="http://en.wikipedia.org/wiki/Whisker_(metallurgy)">Wikipedia - Metal Whiskering</a></li>
<li><a href="http://www.insidescience.org/content/new-theory-explains-mysterious-growth-metal-strands/1642">Inside Science - New Theory Explains Mysterious Growth of Metal Strands</a></li>
<li><a href="http://nepp.nasa.gov/Whisker/background/index.htm">NASA - Basic Information Regarding Tin Whiskers</a></li>
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Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com1tag:blogger.com,1999:blog-4259970604941160665.post-58829063173034451522014-02-08T07:47:00.004-08:002014-02-08T07:55:42.649-08:00Windows 8 - Hibernate Option<div style="text-align: justify;">
It has been a rather long hiatus from my technical blog, so I wanted to start the year off with something light yet useful for the readers. Since I just got myself a new laptop, running on the dreaded Windows 8 instead of the familiar territories of Windows 7, I decided to share one of the frustrating encounters here as well as how to tackle it.</div>
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For some unfathomable reason, the Hibernate option is not available when Shut Down is selected. This has been a very useful option for me, especially when I do not want to shut down all my applications and restart them again when I call it a day. To have all those programs ready to work when I have the laptop boot up again is really time saving, and I just could not believe that Microsoft would just do away with it.</div>
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Sure enough, online articles started offering tips and advice as to how to get that option back. And it was as I suspected - Microsoft still had the option available albeit hidden off and not even a cursory glance through all option would tell you how to get it back. Posted here are the steps to enable the options.</div>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-STF_IfWgOXk/UvZKykp_iXI/AAAAAAAAAVQ/gdoO7HJRQ_o/s1600/Power_hibernate.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://1.bp.blogspot.com/-STF_IfWgOXk/UvZKykp_iXI/AAAAAAAAAVQ/gdoO7HJRQ_o/s1600/Power_hibernate.jpg" height="320" width="282" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>When you go for shutdown sequence, the option of Hibernate is unavailable to the user. Once the following steps are performed, the option will be available to the user once more.</i></span></td></tr>
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<i><b>Step 1:</b> </i><i><b><u>Windows + W</u> ->> type "power" ->> click on <u>Change What The Power Buttons Do</u></b></i><br />
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<i>Access the Power Settings. This can be done through <b><u>Windows key + W</u></b> (to bring up the Settings Search menu) entering the Search screen and type "power". Another way to do this is to enter the Search screen and select Settings, then type "power". Click on <u><b>Change What The Power Buttons Do</b></u>.</i></blockquote>
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<a href="http://2.bp.blogspot.com/-U9eL_Fw2W3k/UvZKyx6PKlI/AAAAAAAAAVM/y3dNxU7U-l4/s1600/Power_hibernate2.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://2.bp.blogspot.com/-U9eL_Fw2W3k/UvZKyx6PKlI/AAAAAAAAAVM/y3dNxU7U-l4/s1600/Power_hibernate2.jpg" height="360" width="640" /></a></div>
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<i><b>Step 2:</b> </i><i><b>Click <u>Change Settings That Are Currently Unavailable</u></b></i><br />
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<i>On the pop up screen, you may notice that the option Hibernate is actually shown under Shutdown Settings, yet it is greyed out and cannot be interacted with. Click on <b><u>Change Settings That Are Currently Unavailable</u></b> right there on the top of the screen.</i></blockquote>
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<a href="http://1.bp.blogspot.com/-xftUxJO696U/UvZJ9Qs1noI/AAAAAAAAAU4/lUAaGV6w3Wk/s1600/Power_hibernate3.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://1.bp.blogspot.com/-xftUxJO696U/UvZJ9Qs1noI/AAAAAAAAAU4/lUAaGV6w3Wk/s1600/Power_hibernate3.jpg" /></a></div>
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<i><b>Step 3:</b> </i><b><i>Check <u>Hibernate</u> option under <u>Shutdown Settings</u></i></b><br />
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<a href="http://4.bp.blogspot.com/-FI87XSc43TI/UvZJ9XSbOsI/AAAAAAAAAUw/JAvDSj3OinA/s1600/Power_hibernate4.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://4.bp.blogspot.com/-FI87XSc43TI/UvZJ9XSbOsI/AAAAAAAAAUw/JAvDSj3OinA/s1600/Power_hibernate4.jpg" /></a></div>
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Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com0tag:blogger.com,1999:blog-4259970604941160665.post-13865354197244760692013-07-28T01:16:00.001-07:002013-07-28T01:16:54.059-07:00Pro/ENGINEER - making edges more visible<div style="text-align: justify;">
If you are a Pro/ENGINEER user who finds the fact that the model's edges are not easily distinguished and causing features hard to find, then you may try this option to make the edges more prominent.</div>
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<a href="http://4.bp.blogspot.com/-7Bh45U6-8Ac/UfTQWvmiDpI/AAAAAAAAASE/3_zlUFyi9ho/s1600/Picture1-001.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="330" src="http://4.bp.blogspot.com/-7Bh45U6-8Ac/UfTQWvmiDpI/AAAAAAAAASE/3_zlUFyi9ho/s640/Picture1-001.jpg" width="640" /></a></div>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-DkeY0WLJddk/UfTQYBP4mAI/AAAAAAAAASM/ksV4Lza4f3M/s1600/Picture2-001.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="360" src="http://4.bp.blogspot.com/-DkeY0WLJddk/UfTQYBP4mAI/AAAAAAAAASM/ksV4Lza4f3M/s400/Picture2-001.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>A sample 3D model in the original settings (above), with the circled area zoomed in (below).</i></span></td></tr>
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<b><i>Step 1: <u>View</u> ->> <u>Display Settings</u> ->> <u>Model Display...</u></i></b></div>
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<a href="http://2.bp.blogspot.com/-usuOZz5azsM/UfTQMyIBgoI/AAAAAAAAAR0/E5xj4fWsSqU/s1600/Picture3-001.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="http://2.bp.blogspot.com/-usuOZz5azsM/UfTQMyIBgoI/AAAAAAAAAR0/E5xj4fWsSqU/s640/Picture3-001.jpg" width="478" /></a></div>
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<b><i>Step 2: click on the tab named <u>Shade</u> ->> check the checkbox <u>With Edges</u> ->> click <u>OK</u></i></b></div>
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<a href="http://3.bp.blogspot.com/-4yRGBZc5EY0/UfTQQx5di9I/AAAAAAAAAR8/6UiNbpvp3fk/s1600/Picture4-001.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://3.bp.blogspot.com/-4yRGBZc5EY0/UfTQQx5di9I/AAAAAAAAAR8/6UiNbpvp3fk/s1600/Picture4-001.jpg" /></a></div>
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The result is clearly different from the original settings, and the features are clearly distinguished after the settings have been applied.</div>
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<a href="http://2.bp.blogspot.com/-3bSOtAF-gnM/UfTRLd0Rm1I/AAAAAAAAASY/vPTsmvwP4fg/s1600/Picture5-001.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="342" src="http://2.bp.blogspot.com/-3bSOtAF-gnM/UfTRLd0Rm1I/AAAAAAAAASY/vPTsmvwP4fg/s640/Picture5-001.jpg" width="640" /></a></div>
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<a href="http://2.bp.blogspot.com/-1HcwVjsq6v8/UfTSUXmexKI/AAAAAAAAAS4/sJzzBVLYMzc/s1600/Picture6-001.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="342" src="http://2.bp.blogspot.com/-1HcwVjsq6v8/UfTSUXmexKI/AAAAAAAAAS4/sJzzBVLYMzc/s400/Picture6-001.jpg" width="400" /></a></div>
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It is worthy to note though that the color and its highlight and shadows setting affects how visible the edges are. After applying this setting, individual color settings may still need to be tuned to get a more prominent edge.</div>
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Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com1tag:blogger.com,1999:blog-4259970604941160665.post-71370674144890082852013-07-22T22:06:00.000-07:002013-07-22T22:06:24.096-07:00Bimetallic Coin – The Making<div dir="ltr" style="text-align: left;" trbidi="on">
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Singapore has just launched its third series of coins last month, with the $1 coin stealing the limelight with its bimetallic composition. A golden brown outer ring encased a chrome inner core, which in fact are respectively brass plated and nickel plated metal. Much as a coin calls to mind the buying and selling process, there are also engineering involved in the metallic item – the manufacturing of it.</div>
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<a href="http://3.bp.blogspot.com/-fJY5g8emEZo/Ue1nXBycgmI/AAAAAAAAAQs/o99U8rFyu5I/s1600/Untitled.png" imageanchor="1"><img border="0" height="197" src="http://3.bp.blogspot.com/-fJY5g8emEZo/Ue1nXBycgmI/AAAAAAAAAQs/o99U8rFyu5I/s640/Untitled.png" width="640" /></a></div>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-N6V-LDXTQmI/Ue1ndqlEx2I/AAAAAAAAAQ0/dMZgQOIkwqA/s1600/sgd1.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://2.bp.blogspot.com/-N6V-LDXTQmI/Ue1ndqlEx2I/AAAAAAAAAQ0/dMZgQOIkwqA/s1600/sgd1.png" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>The array of new Singaporean coins launched in June 2013, with the $1 bimetallic coin taking center stage in this article's discussion (images taken from <a href="http://www.mas.gov.sg/newcoins">Monetary Authority of Singapore website</a>).</i></span></td></tr>
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Coins are generally manufactured through a metal stamping process known in the circle with the uncreative name of ‘coining’. Basically a strip of metal, usually plated metal, clad metal or metal alloys, is fed into the stamping machine which holds 2 pieces of dies. Die, has nothing to do with death – that is the term for the specialized tool used for shaping or cutting metal. The 2 dies hold an image on each of them, and when pressed together onto the metal strip, will form the images on it as well as cutting the formed piece, usually round in the matter of coins, from the strip.</div>
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Despite the obvious different outlook, bimetallic coins are made through the same process, with some extra steps. The process is broken down via the following general steps:</div>
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<li style="text-align: justify;">The metal strip that will provide the outer ring is punched out of the strip, with a hole punched out of it at the same time. This leaves a ring of metal.</li>
<li style="text-align: justify;">The metal strip meant to be the inner core will be punched out of its strip as well, leaving a simple round piece of metal.</li>
<li style="text-align: justify;">Milling is performed on the side of the inner core to create ridges.</li>
<li style="text-align: justify;">Both inner core and outer ring is placed together and stamped with the 2 dies which carry the images.</li>
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The pressure of forming the coins will force the metal the flow. In this case, the outer ring’s inner diameter wall will flow into the ridges of the inner core, locking them together through the forming process. </div>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-Vg-WLyBb30o/Ue1o5Z5LEqI/AAAAAAAAARE/7SnD796CTnc/s1600/bimetallicSIZE174x100.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://3.bp.blogspot.com/-Vg-WLyBb30o/Ue1o5Z5LEqI/AAAAAAAAARE/7SnD796CTnc/s1600/bimetallicSIZE174x100.jpg" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>A cross-section illustration of the 2 pieces forming the bimetallic coin (image taken from <a href="http://www.fleur-de-coin.com/articles/bi-metallic">Fleur-de-coin</a>).</i></span></td></tr>
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The extra process of forming the ridges is important. Despite the high pressure involved in pressing the 2 pieces of metal together, the fact that the parting between them is vertical, or perpendicular to the plane of the coin, means that a slightly high force such as simply striking a coin on the corner of a table, may dislodge the inner core from the outer ring, essentially destroying the coin despite the fact that the metals themselves are intact. </div>
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Both pieces may also twist from each other, creating an image that is not in sync with each other, thus a misaligned image. The ridges and the flowing of metal from one piece thus become an anti-twisting mechanism as well as locking mechanism to prevent them being dislodged too easily. </div>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-A3qZL_qjjYg/Ue1qGTNi8gI/AAAAAAAAARU/Fc8HJTHM3I4/s1600/r2e1.gif" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://3.bp.blogspot.com/-A3qZL_qjjYg/Ue1qGTNi8gI/AAAAAAAAARU/Fc8HJTHM3I4/s1600/r2e1.gif" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>The 1 and 2 Euro coins are also bimetallic coins (image taken from <a href="http://www.worldbcnews.com/newissues/newissues.html">WBCN</a>).</i></span></td></tr>
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The process of manufacturing a bimetallic coin may seem relatively straightforward, but an engineer will appreciate the difficulty of design which belies such simple process. The simpler a process, the higher the constraint it places on a design. The process itself can be found in patent offices, such as <a href="http://www.google.com/patents/US5094922">US5094922</a>, <a href="https://www.google.com/patents/EP0529349B1?cl=en&dq=EP0529349B1&hl=en&sa=X&ei=oGjtUcf3K8r_rAf06oGYCg&ved=0CDYQ6AEwAA">EP0529349B1</a> and <a href="https://www.google.com/patents/EP0868315B1?cl=en&dq=EP0868315B1&hl=en&sa=X&ei=uGjtUdfLAYXprQf-w4GwDg&ved=0CDYQ6AEwAA">EP0868315B1</a>.</div>
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Sources: </div>
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<li><a href="http://www.mas.gov.sg/newcoins">Monetary Authority of Singapore - Singapore’s New Coins</a></li>
<li><a href="http://en.wikipedia.org/wiki/Coining_(metalworking)">Wikipedia: Coining (metalworking)</a></li>
<li><a href="http://en.wikipedia.org/wiki/Coining_(mint)">Wikipedia: Coining (coin making)</a></li>
<li><a href="http://en.wikipedia.org/wiki/Die_(manufacturing)">Wikipedia: Die (manufacturing)</a></li>
<li><a href="http://www.fleur-de-coin.com/articles/bi-metallic">Fluer-de-coin: Bimetallic coin</a></li>
<li><a href="http://www.core77.com/blog/object_culture/how_they_make_bi-metallic_coins_12587.asp">Core 77 - How They Make Bimetallic Coin</a></li>
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Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com2tag:blogger.com,1999:blog-4259970604941160665.post-66933831306635877762013-04-28T04:40:00.000-07:002013-04-28T04:42:54.909-07:00Indentation Hardness<div style="text-align: justify;">
Among the three hardness types shared in the previous article, indentation hardness is the one which most engineers are familiar with. In fact, I bet that the general reply to the definition of hardness matches that of indentation hardness so much so that they are interchangeable in most discussions. Even engineering textbooks seldom mention indentation hardness as a separate topic – it is instead discussed as a hardness topic without an in-depth subtopic on other hardness types. </div>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-U-Ozszg48-g/UXz3PPJTbHI/AAAAAAAAAPY/v0V03A2zlZI/s1600/ball_indent.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="366" src="http://3.bp.blogspot.com/-U-Ozszg48-g/UXz3PPJTbHI/AAAAAAAAAPY/v0V03A2zlZI/s640/ball_indent.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>Ball indenter used for Rockwell hardness testing. Different macroindentation test methods uses different indenter geometry and measures different dimensions of the indentation geometry (image taken from <a href="http://www.instron.us/wa/acc_catalog/prod_list.aspx?cid=1153&cname=Rockwell%20Indenters%20and%20Ball%20Penetrators">Instron</a>).</i></span></td></tr>
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Indentation hardness quantifies the resistance of a sample to material deformation, plastic deformation to be specific, due to the effect of a constant compressive load of a sharp object, hence the term “indentation”. In this test, a specific indenter is exerted onto the test material until an indentation is formed, of which dimension is measured and determines the hardness in accordance to a certain scale. </div>
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For engineers personally involved in testing materials, it would be important to understand that most indentation tests have <b><u><span style="color: orange;">specific load rate</span></u></b> and <b><u><span style="color: orange;">specific dwell time</span></u></b> (the period in which the indenter load is held without moving), but not all of them are so. </div>
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Depending on the load that is applied, the indentation hardness measurement method could be divided into 3 different categories: </div>
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<li><b><span style="color: orange;">Macroindentation test:</span></b> This is the usual method which most of us use. The load applied is larger, typically more than 100N (~1kgf). The usual hardness scales of Rockwell hardness (HR), Brinell hardness (HB) and Vickers hardness (HV) are part of this category. </li>
<li><b><span style="color: orange;">Microindentation test:</span></b> Tests with lower applied load, typically less than 2N (~200gf), although the range of test load can reach up to 1kgf and still fall within this category. </li>
<li><b><span style="color: orange;">Nanoindentation test:</span></b> This test is so named because of an even lower applied load, ranging from 1µN to 100mN. At such small loads, the indentation area is only a few square micrometers across, even in nanometer scale, hence the name. </li>
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There are a variety of hardness scales within macroindentation hardness, each of them different from the other in the employment of different indenter, indenter tip geometry, dimension of indentation geometry being measured and the expected material upon which the method is employed upon. This is a topic which I could share in another article in itself base on what I understand as well as on what I read from different sources. </div>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-BV3mDg1NuGw/UX0F4S2OQGI/AAAAAAAAAPo/anquIsILaEQ/s1600/indent-7.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="360" src="http://3.bp.blogspot.com/-BV3mDg1NuGw/UX0F4S2OQGI/AAAAAAAAAPo/anquIsILaEQ/s640/indent-7.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>Indentation of a Niobium sample using a silicon tip, viewed under Scanning Electron Microscopy (SEM). Nanoindentation creates very small dent geometry which is invisible to the naked eye (image taken from <a href="http://www.nanotechnik.com/nanoindentation.html">Kleindiek Nanotecknik</a>).</i></span></td></tr>
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<b>A Comparative Property </b></div>
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Hardness cannot be considered as a fundamental property. It is an arbitrary quantity which provides a comparative idea of the material’s resistance against plastic deformation against a predetermined scale. </div>
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As different measurement method provides different scale, the scale themselves have no simple relationship between each other, although comparison charts can be used to convert to an approximate value in another scale for certain materials. These comparison charts are material specific, so a comparison chart for alloy steel may not be useful for aluminum alloy. </div>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-uSXn6FaVpOk/UX0G7_CihwI/AAAAAAAAAP0/utLAiVJ0-1Y/s1600/rockwell_conversion_chart.gif" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="370" src="http://1.bp.blogspot.com/-uSXn6FaVpOk/UX0G7_CihwI/AAAAAAAAAP0/utLAiVJ0-1Y/s640/rockwell_conversion_chart.gif" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>A comparison graph between Rockwell hardness scale and Vickers hardness scale. No mathematical exact conversion is possible, and conversion between scales are only approximate. Extrapolation is not advised due to this particular reason (image taken from <a href="http://www.gordonengland.co.uk/hardness/rockwell_conversion_chart.htm">Surface Engineering Forum</a>).</i></span></td></tr>
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<b>Surface or Bulk Property? </b></div>
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Seldom emphasized is the fact that hardness is more dependent on surface property than bulk property. The general idea of indentation hardness testing is to measure material properties, especially tensile strength, in a less destructive manner rather than break apart a sample piece just to measure its property. For quality control, this is a rather important aspect since a quick measurement with a handheld Rockwell hardness tester could determine a batch’s property through a quick and inconspicuous dent on the surface of a few cast ingots. </div>
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But hardening methods such as precipitation hardening and work hardening, as well as passivating film which formed naturally on the surface of metal, are only superficial. Just because the surface is hard, it does not represent the core of the material bulk to be in the same condition. </div>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-a74NIdef2uo/UX0I2matnJI/AAAAAAAAAQI/q6eY6pjLDRI/s1600/1-s2.0-S0040609009021191-gr3.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="396" src="http://1.bp.blogspot.com/-a74NIdef2uo/UX0I2matnJI/AAAAAAAAAQI/q6eY6pjLDRI/s640/1-s2.0-S0040609009021191-gr3.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>FE-SEM (Field Emission Scanning Electrion Microscopy) image of a 3-layer passivation film (MgF<sub>2</sub>/Mg-Zn-F/MgF<sub>2</sub>) passivation film sputtered on PEN. The overall thickness of the film is only about 200nm. Hardness of such thin material may require the use of nanoindentation hardness testing (image taken from <a href="http://www.sciencedirect.com/science/article/pii/S0040609009021191">ScienceDirect on the topic of "Evaluation of Thin Film Passivation Using Inorganic Mg-Zn-F Heterointerface for Polymer LED</a>).</i></span></td></tr>
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What indentation hardness could do which a uniaxial tensile test cannot is to determine the said surface property, such as the strength of a coating film or passivating film. The film could be micrometers thick, and cannot be separated from the bulk material in a nondestructive manner and still reveal its mechanical property. </div>
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It would be important to note that surface finishes will not influence hardness, but may affect the measurement if the indentation geometry is not large compared to the surface roughness. The dimensions of an indentation on a mirror finished surface will prove to be much easier to measure with the indented geometry clearly defined against its surroundings. Finding the edges of the small dent in a rough surface may be akin to finding a needle in a haystack.</div>
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<b>Sources:</b></div>
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<li><a href="http://en.wikipedia.org/wiki/Indentation_hardness">Wikipedia - Indentation Hardness</a></li>
<li><a href="http://en.wikipedia.org/wiki/Hardness">Wikipedia - Hardness</a></li>
<li><a href="http://www.engineershandbook.com/Tables/hardness.htm">Engineer's Handbook - Hardness Conversion Table</a></li>
<li><a href="http://en.wikipedia.org/wiki/Nanoindentation">Wikipedia - Nanoindentation</a></li>
<li><a href="http://mee-inc.com/nano.html">Materials Evaluation and Engineering, Inc. - Nanoindentation</a></li>
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Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com4tag:blogger.com,1999:blog-4259970604941160665.post-59319201974926935972013-04-18T09:47:00.000-07:002013-04-28T04:41:32.922-07:00Hardness - How Hard Is Hard?<div style="text-align: justify;">
It is quite easy to say that a piece of metal is harder than a block of rubber, but how hard is hard? And is a cast iron harder than a stainless steel sheet? How would one find out information about hardness when you are reading the material properties from a specification sheet? </div>
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In fact, when I read more into this property, it is not as simple as we usually would have thought, seeing that we use the descriptive term daily in our conversation. It could be said that: </div>
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<i><b><span style="color: orange;">Hardness</span></b> is a measure of how resistant solid matter is to various kinds of permanent shape change when a force is applied. </i></blockquote>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-7_ib2KGzRBI/UXAhbx2JgFI/AAAAAAAAAPA/yPxED1JwZnI/s1600/bigstock-Seven-Diamonds-2751993.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="426" src="http://1.bp.blogspot.com/-7_ib2KGzRBI/UXAhbx2JgFI/AAAAAAAAAPA/yPxED1JwZnI/s640/bigstock-Seven-Diamonds-2751993.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>Diamond - not only were they a fascination with the ladies, they were also a fascination of engineers. With its reputation of being the hardest substrate ever known, it could cut through almost everything else. So how would you define the hardness of a diamond? (image taken from <a href="http://jonathansfinejewelers.com/services/loose-diamond-sales/#axzz2QpkQOifX">Jonathan's Fine Jewelers</a>)</i></span></td></tr>
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So if you press a finger with a certain amount of force onto a piece of sponge, and the same amount of force onto a piece of steel, you will feel that you could deform the sponge more than the steel, hence the conclusion that the steel is harder. But you will also realize that the force could be applied in different ways – you could press or you could scratch. Even pressing onto a surface depends on the surface area of contact – a sharper item could go deeper into an item compared to a rounder contact. </div>
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In view of the complexity involved behind the deformation of material under force, this property is usually measured in 3 different ways, thus generating 3 different hardness types: indentation hardness, scratch hardness, and rebound hardness.</div>
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<li style="text-align: justify;"><b><span style="color: orange;">Indentation hardness:</span></b> measurement of the resistance to permanent deformation from the effect of a constant compression load from a sharp object, applied within a predefined period of time. Defined by measuring critical dimensions of the indentation left by a specifically dimensioned and loaded indenter.</li>
<li style="text-align: justify;"><b><span style="color: orange;">Scratch hardness:</span></b> measurement of the resistance to fracture or permanent deformation due to friction from sharp object. On coatings, this is the force necessary to cut through the film to expose the substrate.</li>
<li style="text-align: justify;"><b><span style="color: orange;">Rebound hardness:</span></b> measures the height of the bounce of a measurement device dropped from fixed height onto the material.</li>
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<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>An image of a Rockwell Hardness tester. Indentation hardness has a variety of testing methods, thus generating a variety of test equipment. Even so, all of them are performed based on the same concept, only the indentor and defined load is different (image taken from <a href="http://encyclopedia2.thefreedictionary.com/Rockwell+hardness">The Free Dictionary</a>).</i></span></td></tr>
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The measurement method depends on the area of application, and it is usually sufficient for only one of the above methods to be performed. </div>
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<li style="text-align: justify;"><b><span style="color: orange;">Scratch hardness</span></b> is usually synonymous with scratch resistance, and is more of a surface property than a bulk property, although the latter is not without its role. This is usually applied to test coatings, plating, and other surface films. </li>
<li style="text-align: justify;"><b><span style="color: orange;">Indentation hardness</span></b> is closer to the general understanding of the term “hardness”, and it is also the method with the most different equipment to measure. This is because more study had been done in this area, and different material and application requires equipments which are more suitable than others.</li>
<li style="text-align: justify;"><b><span style="color: orange;">Rebound hardness</span></b> is less applied in hardness measurements. Also known as dynamic hardness, this is more applicable to testing the elasticity of the material, with more elastic material allowing a higher bounce of the measurement head.</li>
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<li><a href="http://en.wikipedia.org/wiki/Hardness">Wikipedia - Hardness</a></li>
<li><a href="http://www.calce.umd.edu/TSFA/Hardness_ad_.htm">CALCE - Centre for Advanced Life Cycle Engineering</a></li>
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Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com0tag:blogger.com,1999:blog-4259970604941160665.post-48102031466682516822012-12-01T10:42:00.001-08:002012-12-01T10:51:16.679-08:00Tiger Stone - Brick Road Laying Machine<div dir="ltr" style="text-align: left;" trbidi="on">
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Road paving is one of those physically tasking work in which not much could be automated. Or is it? For brick laying in those brick roads though, a Dutch industrial company named Vanku introduced a machine which could save time and transform the back breaking task into one of relative ease.</div>
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<a href="http://3.bp.blogspot.com/-o2_ZICvHBz8/ULpH8kcL2HI/AAAAAAAAAN0/I8eZq48Bgyk/s1600/BRICK_ROAD_2_TEXTURE_by_Jay_B_Rich.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="270" src="http://3.bp.blogspot.com/-o2_ZICvHBz8/ULpH8kcL2HI/AAAAAAAAAN0/I8eZq48Bgyk/s640/BRICK_ROAD_2_TEXTURE_by_Jay_B_Rich.jpg" width="640" /></a></div>
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In comes Tiger Stone, a road-wide brick laying machine that looked nothing like a tiger and more like a film laminating machine. A road as wide as 6 meters could have 400 m<sup>2</sup> of the road completed within a day as opposed to the 75 - 100 m<sup>2</sup> completed, assuming that the same amount of people are working on the task, namely 2 operators.</div>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-8YuqgfxcIkw/ULpJEQe9epI/AAAAAAAAAN8/EH5F-l8fsqk/s1600/20101118302.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="428" src="http://2.bp.blogspot.com/-8YuqgfxcIkw/ULpJEQe9epI/AAAAAAAAAN8/EH5F-l8fsqk/s640/20101118302.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>Tiger Stone could work with a road pavement as wide as 6 meters, and no more than that. Smaller machines with width of 4 and 5 meters are available as well. Does look like a film laminating machine, doesn't it? </i></span><i style="color: cyan; font-family: Georgia, 'Times New Roman', serif; font-size: medium;"> (image taken from <a href="http://www.inewidea.com/2010/11/18/34852.html">I New Idea</a>)</i></td></tr>
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The machine has the ability to move according to the direction of the road being paved, thanks to built-in sensors which could detect the edge of the curb, allowing it to navigate roughly along the direction of the expected route.<br />
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Having said that, this machine is more in the semi-automated category than automated. The bricks need to be arranged in the desired layout and fed into the slot. What the machined really does is to let the bricks lock to each other through the aid of gravity and roll off its feeder onto the road, creating a brick laid road in the process. The process itself is as ingenious as it is simple.<br />
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-MiHooCn5JKw/ULpKif6QWpI/AAAAAAAAAOE/Ll-Cu-36ukY/s1600/tigerstone-1.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="480" src="http://3.bp.blogspot.com/-MiHooCn5JKw/ULpKif6QWpI/AAAAAAAAAOE/Ll-Cu-36ukY/s640/tigerstone-1.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>Human operators are still required to place the bricks, prepared and stored at the bin to the front, to be aligned to whatever layout of bricks is wanted and fed into the slot, as is being done by this operator. Still, this minimized the workload and time consumption rather drastically (image taken from <a href="http://www.gizmag.com/tiger-stone-lays-paving-bricks/16951/">Gizmag</a>).</i></span></td></tr>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-pEd3ZXCJNAw/ULpMh5ZUrnI/AAAAAAAAAOM/j72LVYOtI4g/s1600/0000a7ac_big.jpeg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="480" src="http://4.bp.blogspot.com/-pEd3ZXCJNAw/ULpMh5ZUrnI/AAAAAAAAAOM/j72LVYOtI4g/s640/0000a7ac_big.jpeg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>Never seen one in action in my country yet, but the brick section seemed to match each other well even after they were rolled off the feeder of the machine (image taken from <a href="http://avaxnews.net/fact/Tiger_Stone_A_Fast_and_Tidy_Drafting_Brick_Road_Machine.html">Avaxnews</a>).</i></span></td></tr>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-ib8tV3XtggI/ULpNaYBBh3I/AAAAAAAAAOU/GMMTkB_WKkc/s1600/20101118308.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="480" src="http://4.bp.blogspot.com/-ib8tV3XtggI/ULpNaYBBh3I/AAAAAAAAAOU/GMMTkB_WKkc/s640/20101118308.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>By arranging the layout of the bricks, it is possible to lay the pavement for 2 different sections together, since human operators are used to feed the correct bricks at the correct arrangement anyway (image taken from <a href="http://avaxnews.net/fact/Tiger_Stone_A_Fast_and_Tidy_Drafting_Brick_Road_Machine.html">I New Idea</a>).</i></span></td></tr>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-vR4cv2Zxr8g/ULpNbKH7wHI/AAAAAAAAAOY/wlmo39ZvnTY/s1600/20101118310.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="480" src="http://4.bp.blogspot.com/-vR4cv2Zxr8g/ULpNbKH7wHI/AAAAAAAAAOY/wlmo39ZvnTY/s640/20101118310.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan;"><span style="font-family: Georgia, Times New Roman, serif; font-size: small;"><i>Voila! The road is paved! 2 road sections are paved in fact... </i></span><i style="font-family: Georgia, 'Times New Roman', serif; font-size: medium;">(image taken from <a href="http://avaxnews.net/fact/Tiger_Stone_A_Fast_and_Tidy_Drafting_Brick_Road_Machine.html">I New Idea</a>)</i></span></td></tr>
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For developed countries where laborers' wage are getting higher and less people are willing to perform such stressful tasks, this machine could be a godsend, replacing the once back breaking task to slight less back breaking. Given the nature of human ingenuity, it could be only years before a machine could fully take the task of road laying from human hands.<br />
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More info can be acquired at the below websites:<br />
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<ul>
<li><a href="http://www.tiger-stone.nl/index.php?option=com_content&view=article&id=50&Itemid=59">Tiger Stone website (in Dutch)</a></li>
<li><a href="http://www.gizmag.com/tiger-stone-lays-paving-bricks/16951/">Gizmag: The Brick Road Laying Tiger Stone</a></li>
<li><a href="http://www.inewidea.com/2010/11/18/34852.html">I New Idea: Tiger Stone Brick Machine</a></li>
<li><a href="http://avaxnews.net/fact/Tiger_Stone_A_Fast_and_Tidy_Drafting_Brick_Road_Machine.html">Avaxnews: Tiger Stone – A Fast and Tidy Drafting Brick Road Machine</a></li>
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Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com2tag:blogger.com,1999:blog-4259970604941160665.post-45755579378358909332012-11-04T01:21:00.000-07:002012-11-04T07:35:11.494-08:00Semiconductor Technology: Moore's Law<br />
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<a href="http://3.bp.blogspot.com/-fShwfpY3o7k/UJYp2grRPEI/AAAAAAAAAE4/pNFbhphaQpk/s1600/image-1971695622.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em; text-align: justify;"><img border="0" height="249" src="http://3.bp.blogspot.com/-fShwfpY3o7k/UJYp2grRPEI/AAAAAAAAAE4/pNFbhphaQpk/s320/image-1971695622.jpg" width="320" /></a></div>
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Just look at that brick handphone. Does it seem like it was ages ago that telephones started to become mobile? The first hand-held mobile phone is, infact, not even 50 years old yet. First to be introduced in 1973 and commercially available by 1980's to customers who could afford to buy it (costs about USD 4000 back then, which is equivalent to USD 9300 today!) and don't mind carrying a 1 kg extra weight in their briefcase/handbag.</div>
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By contrast, today's mobile phones costs and weights only a small fraction of the earliest brick mobile phone and packs more computing power and has more fuctions and capabilities than one could ever imagine back then. All this thanks to Moore's Law.</div>
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Moore's Law was first introduced by Gordon E. Moore in 1965 which states an observation that the number of transistors on an Intergrated Circuit doubles every two years. Therefore, we could expect anything that relates to semicoductor technology, such as memory devices, digital imaging, storage devices and all electronic gadgets will be more twice as powerful in terms of processing power as they are now in two years time. Other advantages such as smaller size, lighter in weight, higher flexibility, more pixels and better power management are expected to come in tow.</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://lifeboat.com/images/moores.law.technological.evolution.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="411" src="http://lifeboat.com/images/moores.law.technological.evolution.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>Recorded number of transistors in a microprocessor from the 70's to the millennium. (<a href="http://lifeboat.com/ex/technological.evolution">source</a>)</i></span></td></tr>
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Moore's Law serves as a prediction and a roadmap for researches and businesses that are involved in semiconductor technology that encompasses many items such as the computer, mobile phones and many other miscellaneous electronic gadgets that we use in our daily lives. Therefore, as long as research work and funding are given for creating, designing and investigating new methods and materials to improve and enhance this industry, we will continue to grow as a civilization.</div>
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We've seen the transistor shrink in size from a large vacuum tube into tiny micro-sized transistors that are not possible to see with the naked eyes. Now they're already moved into the nano-regions and it does not stop there. Recently, physicists have announced that they are working on a single-atom transistor that might open to a possibility of enormous computing capabilities. So, when do we stop? Do we go even further into the single-atom transistor? Does Moore's Law have a limit? What comes after we've exhausted all the possible materials? I think all the answer to those questions lies with us, on whether we want to pursue a deeper knowledge in this subject and also if anyone cares enough to provide funding for the research.</div>
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References:</div>
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1. Wikipedia: <a href="http://en.wikipedia.org/wiki/Motorola_DynaTAC">DynaTAC</a></div>
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2. Wikipedia: <a href="http://en.wikipedia.org/wiki/Moore's_law">Moore's Law</a></div>
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3. Wired: <a href="http://www.wired.com/wiredenterprise/2012/02/sa-transistor/">Single-atom transistor</a></div>
Miss DIYhttp://www.blogger.com/profile/12466337036387989804noreply@blogger.com0tag:blogger.com,1999:blog-4259970604941160665.post-76045292997339273492012-10-07T03:19:00.003-07:002012-10-07T03:19:40.083-07:00Windows Shortcut Key that Helps<div dir="ltr" style="text-align: left;" trbidi="on">
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Computer applications are no longer just a high tech tool but a necessity in the life of an engineer. For those born past the 80's, using Windows is a breeze, but not so for the seniors who have to struggle with the sudden influx of computers into their work life.</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-RUBe23TjuY8/UHFGseQk22I/AAAAAAAAAMY/nNt8GBW76hk/s1600/Windows_7_v2_by_rehsup.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="400" src="http://2.bp.blogspot.com/-RUBe23TjuY8/UHFGseQk22I/AAAAAAAAAMY/nNt8GBW76hk/s640/Windows_7_v2_by_rehsup.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>Image from <a href="http://rehsup.deviantart.com/art/Windows-7-v2-135277837">DeviantArt's Rehsup</a>.</i></span></td></tr>
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Bear in mind that although computers seem to be around forever, they were only popularly employed in our work space, especially those of the engineering community, around the turn of the century, and not everyone get the chance to be in front of one as well. Most of my seniors who started working in Malaysia around the turn of the century had to take turns using a workstation which had to be shared among a few engineers. When I was in secondary school, PC was something which not everybody could afford or willing to buy.</div>
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Still, most people have no idea about shortcut keys on Windows apart from a few commonly used ones, such as that for Cut, Copy and Paste. For those of us working with CAD applications daily, shortcut keys of these CAD programs become a boon in improving productivity and reducing number of clicks, hence less chance of a sprained wrist and finger joints at the end of the work day.</div>
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Certain Windows shortcut keys are superbly useful, which I had researched around the web and listed down here. Although these may not work on CAD applications, they reduced my time needed to work with Microsoft applications (Word, Excel, Powerpoint...) by saving myself a few extra clicks or extra moments in navigating my cursor to the item.<br />
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<b>Controlling Your Windows</b></div>
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<i><span style="color: yellow;">Alt + Tab</span></i></div>
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Switch between windows. Hold on to <i>Alt</i> and press <i>Tab</i> to switch to cycle through all opened windows. Very useful when your current CAD program hanged.</div>
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<i><span style="color: yellow;">Windows key + M</span></i></div>
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Minimizes all opened windows. Especially useful when you saw your boss walking over while you are chatting on messenger.</div>
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<i><span style="color: yellow;">Windows key + Up arrow</span></i></div>
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Maximizes active window.</div>
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<i><span style="color: yellow;">Windows key + Down arrow</span></i><br />
Minimizes/restores active window.<br />
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<i><span style="color: yellow;">Windows key + Spacebar</span></i><br />
Turns all windows transparent to see the desktop. You need to hold onto <i>Windows key</i> in order to see the desktop (but you can let go of <i>Spacebar</i>), letting go of it will return the screen to normal.<br />
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<b>Visual Connections</b><br />
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<a href="http://3.bp.blogspot.com/-G7c2QLNzpIU/UHFQrGpJ7rI/AAAAAAAAAM8/MnspPuZG21U/s1600/Wind_P.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="131" src="http://3.bp.blogspot.com/-G7c2QLNzpIU/UHFQrGpJ7rI/AAAAAAAAAM8/MnspPuZG21U/s640/Wind_P.jpg" width="640" /></a></div>
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<i><span style="color: yellow;">Windows key + P</span></i><br />
Connects your computer to a projector or another screen.<br />
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<i><span style="color: yellow;">Windows key + Shift + Left/Right Arrow</span></i></div>
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For Dual Monitor connections, this shifts the active monitor to the left/right screen.</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-R4WxwekicbQ/UHFJDs96oWI/AAAAAAAAAMo/wiEYdq1K7VY/s1600/Microsoft-Winodws-7.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="480" src="http://3.bp.blogspot.com/-R4WxwekicbQ/UHFJDs96oWI/AAAAAAAAAMo/wiEYdq1K7VY/s640/Microsoft-Winodws-7.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>Image taken from <a href="http://www.webmastergrade.com/25-high-quality-windows-7-wallpapers/">Webmastergrade</a>.</i></span></td></tr>
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<b>Opening Programs and Manipulating Windows Explorer</b><br />
<i><span style="color: yellow;">Windows + Pause</span></i><br />
Opens System Properties.<br />
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<i><span style="color: yellow;">Windows key + R</span></i><br />
Opens Run dialog.<br />
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<i><span style="color: yellow;">Windows key + F</span></i><br />
Opens Search box.<br />
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<i><span style="color: yellow;">Windows key + E</span></i><br />
Opens Windows Explorer.<br />
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<i><span style="color: yellow;">Ctrl + Shift + N</span></i><br />
Creates new folder.<br />
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<i><span style="color: yellow;">F2</span></i><br />
Renames selected file/folder.<br />
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<i><span style="color: yellow;">Alt + Enter</span></i><br />
Calls out the file/folder's Properties. Same as Right-clicking the file/folder, and select Properties.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-xC3e9ok96oQ/UHFHIKwHZ0I/AAAAAAAAAMg/Lre6eIBOL4s/s1600/Black-Windows-7.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="480" src="http://2.bp.blogspot.com/-xC3e9ok96oQ/UHFHIKwHZ0I/AAAAAAAAAMg/Lre6eIBOL4s/s640/Black-Windows-7.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>Image from <a href="http://www.webmastergrade.com/25-high-quality-windows-7-wallpapers/">Webmastergrade</a>.</i></span></td></tr>
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<b>Combining the Power of Your Mouse</b></div>
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<i><span style="color: yellow;">Ctrl + Scroll Up/Down</span></i></div>
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Enlarges (<i>Scroll Up</i>) or reduces (<i>Scroll Down</i>) the font size of your internet browser or window applications. In Window Explorer, it will scroll through the view type.</div>
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<i><span style="color: yellow;">Ctrl + Click</span></i></div>
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Each click will add or subtract the selected icon/file from your current list of selection. <i>Ctrl</i> needs to be held down constantly while clicking items.</div>
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<i><span style="color: yellow;">Ctrl + Shift + Click</span></i></div>
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Opens the program as administrator. Saves time instead of right-clicking the program and select "Run As Administrator".</div>
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There are more shortcut keys out there. As such, I have went through a lot more than I listed down here, but only these are the ones which I used the most in my job. Interested readers could go through the webpages as listed below or search for more in the net.</div>
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<b>Suggested readings:</b></div>
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<ul>
<li><a href="http://sg.news.yahoo.com/blogs/upgrade-your-life/hidden-powers-mouse-164928637.html">Yahoo News: Hidden Power of Your Mouse</a></li>
<li><a href="http://windowssecrets.com/top-story/a-complete-guide-to-windows-7-keyboard-shortcuts/">WindowsSecrets: A Complete Guide to Windows 7 Keyboard Shortcuts</a></li>
<li><a href="http://www.shortcutworld.com/en/win/Windows_7.html">ShortcutWorld: Windows 7 Shortcuts</a></li>
<li><a href="http://www.guidingtech.com/4535/windows-7-keyboard-shortcut/">GuidingTech: 15 Killer Windows 7 Keyboard Shortcuts That Might Surprise You</a></li>
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Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com0tag:blogger.com,1999:blog-4259970604941160665.post-42886574662591967892012-08-08T20:48:00.002-07:002012-08-08T21:00:25.142-07:00What is the cost of...?<div dir="ltr" style="text-align: left;" trbidi="on">
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The Avengers had assembled, the Dark Knight is rising and Star Wars had ended, but all these doesn't have to be limited to the silver screen. Just as Titanic could be a lesson for an engineer, so could a few other big budget movies.</div>
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For one, if you are the project engineer in charge of estimating the cost of engineering such challenging items as those featured in the movie, how much would they cost? Interestingly, I stumbled into a couple of websites which considered those same questions and presented an estimation which was fun to read although their accuracy warrant further corroboration.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-4wlPxCB5ZH0/UCMz1JEDIeI/AAAAAAAAAL0/FTRok3RxSp0/s1600/hrbvki.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://1.bp.blogspot.com/-4wlPxCB5ZH0/UCMz1JEDIeI/AAAAAAAAAL0/FTRok3RxSp0/s640/hrbvki.jpg" width="424" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><i><span style="color: yellow; font-family: Georgia, Times New Roman, serif; font-size: small;">Image from <a href="http://braveandboldlost.blogspot.sg/2011/08/batman-and-iron-man-2020.html">Super-Team Family</a>.</span></i>
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<b>Cost of being Dark Knight</b><br />
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Cool as he is, Bruce Wayne was born with a silver spoon albeit his tragic past. From his training in his adolescence leading right up to his vigilante days, he did not go through his life without spending a dime. For his crime fighting double life, he needed an armory consisting of mostly unconventional weapons with bat motifs, and this means each and every one of them are designed, prototyped and fabricated without the aid of mass production nor ROI (return of investment).<br />
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Look here to see how much <i>you</i> would need to spend in order to get near to being a Dark Knight (not to mention you need more than just cash to be one). Seems like you will need to save at least <b><span style="color: cyan;">$682 million</span> </b>before steeping towards that dream...</div>
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<a href="http://www.moneysupermarket.com/money/the-cost-of-being-batman-infographic.aspx"><img alt="" border="0" src="http://www.moneysupermarket.com/money/images/batman-720.jpg" width="600" /></a></div>
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<span style="color: yellow; font-family: Georgia, Times New Roman, serif;"><i>Image source: <a href="http://www.moneysupermarket.com/money/">MoneySupermarket</a></i></span></div>
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Certain costs are not taken into consideration in designing and fabricating Batman's items. For one, there would not be labor costs as nobody can make his gadgets since his identity is supposed to be a secret. No mass manufacturing is required as well, and without this concern, he could definitely simplify or even fine tune each of his gadgets to met specifications.<br />
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<b>Cost of being Iron Man</b><br />
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Competing against DC's Batman is Marvel's Iron Man. Both shared a lot of similar traits - both are rich, both have no super powers, both are geniuses, both created their own gadgets, both own listed companies, etc. But even though Bruce Wayne has his share of Bat-somethings, Tony Stark's armament of Iron Man suits, up to and including War Machine's armor, costs more than the former's armory, collecting a whooping <b><span style="color: cyan;">$1.6 billion</span></b> to become the man in a titanium-gold alloy suit.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://dailyinfographic.com/the-cost-of-being-iron-man-infographic" style="margin-left: auto; margin-right: auto;"><img alt="" border="0" src="http://dailyinfographic.com/wp-content/uploads/2012/07/costofbeingironmanlarge.jpg" width="600" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>Image source: <a href="http://dailyinfographic.com/the-cost-of-being-iron-man-infographic">Daily Infographic</a></i></span></td></tr>
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In hindsight, calculation of being Iron Man included his personal sports car, which has nothing to do being the hero himself. Marvel's hero uses more advance gadgets compared to Batman's more primitive ones. The former's arsenal are mainly electronic and computer-aided base whereas the latter relies more on mechanical means to achieve his goal.<br />
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For an engineer like me, I would still prefer a more mechanical means if I were to fight crime. Crime fighting is a dangerous business and I would not want myself to face a system crash while the Mandarin is trying to take my life. But then again, it would be superbly difficult <i>not</i> to have a computer to help perform trivial tasks parallelly to speed things up in the heat of a battle. Talk about dilemma.<br />
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<b>Cost of building Death Star</b><br />
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Now comes the more interesting and more related topic: how much would be needed to build a Death Star? <a href="http://www.centives.net/S/2012/how-much-would-it-cost-to-build-the-death-star/">Centives.net</a> performed the estimation for fun and presented an estimation of about... <b><span style="color: cyan;">$852 quadrillion</span></b>! But even with such an astronomical figure, this is still an underestimation as the estimation is based on amount of steel employed in fabricating the WMD.<br />
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So what else should an engineer take into consideration if he were to build a Death Star so that he will not risk death at the hands of either Darth Vader or Emperor Palpatine?<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://starwars.wikia.com/wiki/Death_Star_II" style="margin-left: auto; margin-right: auto;"><img alt="" border="0" src="http://images3.wikia.nocookie.net/__cb20081001131439/starwars/images/thumb/a/aa/DeathStarII_egvv.jpg/1000px-DeathStarII_egvv.jpg" width="600" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, Times New Roman, serif; font-size: small;"><i>Image from <a href="http://starwars.wikia.com/wiki/Death_Star_II">Star Wars wikia</a></i></span></td></tr>
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<ul>
<li><b><span style="color: orange;">Labor cost:</span></b> Unlike Batman or Iron Man, building a Death Star is not and could not be completed alone. Even with Wookie slaves, there will be need for security personnel, army personnel, supporting personnel, technical personnel and the likes. They will need to be paid for accordingly, and if they are considered as working off-planet and in hazardous condition, they may even need to be covered by insurance.</li>
<li><span style="color: orange;"><b>Process cost:</b></span> Tony Stark may have the ingenuity to invent Iron Man suits with Jarvis and Bruce Wayne could ask his butler to help fabricate his gadgets or buy off-shelf, but neither method could work with building a space station. Steel does not just hold onto each other nor will it withstand the vigor of constant use. Welding, painting, coating and other secondary processes will be required, and all this doesn't come free of charge.</li>
<li><b><span style="color: orange;">Equipment cost:</span></b> You can't just out steel together and expect them to emit a planet destroying laser. Even Iron Man need Jarvis and Batman his Bat-computer. There will be need for hangar, high-power laser emitters, deflector shield generators, tractor beam emitters, ion and hyperdrive engines, and of course, the planet destroying laser emitter in a crater among others. I bet any one of these cost more than the most advance Iron Man suit. A good thing about building in space may be the lack of cranes to overcome gravity but some other supporting structure will still be required for the construction.</li>
<li><b><span style="color: orange;">Logistics cost:</span></b> Even if you manage to secure those tons of steel, they don not come to your doorstep. You will need to calculate the cost of transporting them to the Death Star site, which will depend on number of trips and distance to site, as well as transport used. You will also need to bring your personnel, equipment, and not to forget, Wookie or other slaves, to the build site. In a nutshell, more costs.</li>
<li><b><span style="color: orange;">R&D cost:</span></b> Even a genius like Bruce Wayne or Tony Stark could not conceive all the technology required for realizing a Death Star. Each part of the gigantic space station is a new technology unto itself, and it will require hours upon hours of research and making sure each problem is resolved. Even with the help of digital mockup and automatically generated CAD data from Jarvis, Tony Stark still need to run hours of tests to make sure his hand beams work perfectly. And this is a space station we are talking about. More money.</li>
</ul>
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There will be more that needs to be covered within a quotation for engineering such a feat as the Death Star but the above are just to show how much was not within the consideration of Centives' estimation, as well as how much an engineer estimating for quotation need to research before producing a figure.<br />
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Still, some usual engineering consideration will not be required for the Death Star project. With Sith Lords presiding, workplace safety, workers' welfare, union strikes and labor recruitment will not be part and parcel of a project manager's list of worry points.<br />
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</div>Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com0tag:blogger.com,1999:blog-4259970604941160665.post-20548312242426157922012-07-07T20:12:00.002-07:002012-07-07T20:12:31.170-07:00Gloss - Measurement of Gloss Part 1<div style="text-align: justify;">
As was established in the previous post, <b><span style="color: orange;">gloss</span></b> is determined by <b><u>the amount of light rays being reflected under <span style="color: orange;">specular reflection</span></u></b> as opposed to <b><u><span style="color: orange;">diffuse reflection</span></u></b>. The more rays reflected through the former method, the glossier the surface is. </div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-9IcdMbtB-Yc/T_hF0fLwIyI/AAAAAAAAAKk/Cf8YmXiGWgk/s1600/128649944461477377_d9bb0d6bfd64.jpeg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="490" src="http://1.bp.blogspot.com/-9IcdMbtB-Yc/T_hF0fLwIyI/AAAAAAAAAKk/Cf8YmXiGWgk/s640/128649944461477377_d9bb0d6bfd64.jpeg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>Taktik iPhone case designed by Minimal studio. The surface is described as glossy and although this image is (I suspect) a rendered image, the glossiness of the surface is still conveyed. For quality control, determining the item as meeting the expected gloss level is not acceptable through mere visual inspection (image taken from <a href="http://www.geeky-gadgets.com/lunatik-taktik-shockproof-rugged-iphone-case-video-22-06-2012/">DesignBoom</a>).</i></span></td></tr>
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Gloss could be <u><b>compared qualitatively by comparing reflection of an image off different surfaces</b></u>. Surface exhibiting sharper reflection will be considered glossier. But this is only useful in a qualitative way, and only if both surface reflections are distinctly different. Different observant will have different sight and recognition capability as well, so this method is physiologically affected. This qualitative method will not suffice as a quality control method.</div>
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Just as is the case for all measurement, gloss measurement requires a quantitative unit. This is the <b style="color: orange;">Gloss Unit (G.U.)</b>, and can be measured by <b><span style="color: orange;">glossmeter</span></b>. This unit is defined, according to <a href="http://www.gloss-meters.com/GlossIntro2.html#4">GlossMeters</a>, as:</div>
<blockquote class="tr_bq" style="text-align: justify;">
<i><b>Gloss Unit (G.U.)</b>: a scaling based on amount of reflected light off a highly polished black glass standard with a defined refractive index, and having a specular reflectance of 100 G.U. at a specified angle.</i></blockquote>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-rYm2nHVLT6A/T_hIAMlJZ0I/AAAAAAAAAKs/E2eGwFSWmZQ/s1600/gloss-meter.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://3.bp.blogspot.com/-rYm2nHVLT6A/T_hIAMlJZ0I/AAAAAAAAAKs/E2eGwFSWmZQ/s1600/gloss-meter.jpg" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>A glossmeter from BYK (image taken from <a href="http://www.glossmeters.com/gloss-meter.html">BYK website</a>).</i></span></td></tr>
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A glossmeter measures gloss by <u><b>directing a beam of light at the surface in question at a specific angle, and measuring the amount of reflection</b></u>. The angle used is dependent on the surface type - a highly glossy surface will use a smaller incident angle while a matte surface requires larger incident angle.<br />
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While visual comparison uses the distinctness of the reflected image, gloss measurement uses <u style="font-weight: bold;">the amount of reflected light</u>, i.e. <b style="text-decoration: underline;">intensity of its reflection</b>. And the standard black glass measurement of <b><u>100 G.U. is not the maximum obtainable G.U.</u></b> - it is possible to obtain more than that.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-3FK0bZYJgcw/T_j0_MJEyvI/AAAAAAAAALM/n13kKOPsejI/s1600/Detector.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://3.bp.blogspot.com/-3FK0bZYJgcw/T_j0_MJEyvI/AAAAAAAAALM/n13kKOPsejI/s1600/Detector.jpg" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: cyan; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>Working principle of a glossmeter (image taken from <a href="http://www.gloss-meters.com/GlossIntro2.html#4">GlossMeters</a>).</i></span></td></tr>
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The reasoning behind a higher G.U. than the black glass is due to refraction and reflection. The black glass standard is not a perfect example of specular reflection, so there are still rays of light reflected through diffuse reflection, while others are loss through refraction and absorption in the glass. Transparent materials, such as certain films, may give more than 100 G.U. due to the rays being reflected multiple times.<br />
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<b><u>Material and incident angle</u></b> plays a role in determining the intensity of reflected light.<br />
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<b>1. Nonmetals </b></blockquote>
<blockquote class="tr_bq">
<b><u>G.U. of nonmetals</u></b> such as coatings and plastics are <b><u>angle dependent</u></b>. The amount of light increases with the amount of incident angle. Rays of light not reflected through specular reflection will be lost <b><u>as diffuse reflection</u></b> and <b><u>through absorption by the material</u></b>. This is what happened on the black glass standard, hence 100 G.U. not being the maximum cap. </blockquote>
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<b>2. Transparent material</b></blockquote>
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Transparent materials with high refractive index have the ability to <b><u>reflect the incident rays multiple times</u></b> through its bulk and sending them to the sensor, thus giving a higher value than the black glass (more than 100 G.U.). Certain incident rays which penetrate the surface and enter the material are reflected off the exit surface if it meets the criterion of <b><span style="color: orange;">total internal reflection</span></b>. Less rays are lost through absorption as well since transparent material has <b><u>less light absorbing particles </u></b>compared to translucent material. </blockquote>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><br /><a href="http://4.bp.blogspot.com/-YHqmV7cfArk/T_j4sI0_KLI/AAAAAAAAALY/4KJaB3I7tZ4/s1600/totint2.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://4.bp.blogspot.com/-YHqmV7cfArk/T_j4sI0_KLI/AAAAAAAAALY/4KJaB3I7tZ4/s1600/totint2.jpg" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><i><span style="color: cyan; font-family: Georgia, 'Times New Roman', serif; font-size: small;">Total Internal Reflection explained (image from <a href="http://hyperphysics.phy-astr.gsu.edu/Hbase/phyopt/totint.html">HyperPhysics</a>).</span></i>
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<b>3. Metals</b></blockquote>
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<b><u>G.U. of metals</u></b> are <b><u>less angle dependent</u></b>. And being an opaque material with high reflective properties, <b><u>more rays are reflected through specular reflection</u></b>. Metal surfaces with a polished sheen and mirrorlike finishing could give a reading of 2000 G.U. Such measurements could be presented as <b><span style="color: orange;">% of reflected light</span></b> instead, which gives a value normalized to a max of 100 (ideal case being 100% of light reflected).</blockquote>
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Source: </div>
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<ol style="text-align: -webkit-auto;">
<li><a href="http://www.gloss-meters.com/GlossIntro2.html#4">Glossmeters</a></li>
<li><a href="http://en.wikipedia.org/wiki/Gloss_(material_appearance)">Wikipedia: Gloss</a></li>
<li><a href="http://www.acmasindia.com/measuring-equipments/pdf/gloss-meter.pdf">Acmas Technology</a></li>
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<br /></div>Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com3tag:blogger.com,1999:blog-4259970604941160665.post-28505588137058141072012-06-26T00:00:00.000-07:002012-07-07T02:37:49.131-07:00Gloss - A Perception of Surfaces Part 2<div style="text-align: justify;">
Unlike other physical measurements, gloss measurement is not as straightforward. But it isn't difficult either, once one understood how gloss is perceived and interpreted by the human eye.</div>
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<b><span style="color: orange;">Gloss</span></b> is <b><u>an aspect of visual perception of objects</u></b>, and it is <b><u>an attribute of surfaces</u></b>. With this in mind, any material could be made to meet the requirement of any gloss level as long as the technology exists and the method economic. </div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/--LTCwMQ4PXk/T9zNiN4ofaI/AAAAAAAAAKE/vYB-qn-hq3Y/s1600/438036.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="426" src="http://2.bp.blogspot.com/--LTCwMQ4PXk/T9zNiN4ofaI/AAAAAAAAAKE/vYB-qn-hq3Y/s640/438036.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>What in this picture makes you think that the car's exterior is "glossy"? What causes this term to come to mind? (image taken from <a href="http://www.ziebartcardetailingfairfax.com/438023/2012/05/04/what-is-diamond-gloss-and-what-can-it-do.html">Ziebart</a>)</i></span></td></tr>
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A metal surface could be made matte through sand blasting or cast from a textured mold, or it could be polished to a mirror finish. The challenge is to maintain that the surface quality is consistent from part to part, and that requires measurement.</div>
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So how does the human eye perceive gloss? What did the eye take in which the mind considers as "high gloss" or "low gloss"? Take an anti-glare film which you may be using on your laptop or monitor screen right now. You may notice that the surface of the film is rough and textured, instead of being smooth and shiny. The term which your mind is screaming at you would be "matte". And it is right. But why is it "matte"? The answer lies in the same reason on why it is anti-glare - because it scatters light.</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-2Gc8wPvBZuA/T9zLFGvMIGI/AAAAAAAAAJ8/WTMOXYTddDc/s1600/MXFilmOniMacCompare05S.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="404" src="http://1.bp.blogspot.com/-2Gc8wPvBZuA/T9zLFGvMIGI/AAAAAAAAAJ8/WTMOXYTddDc/s640/MXFilmOniMacCompare05S.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>A screen with anti-glare film vs one without. Notice the image of the ceiling light reflected off both screens. (image taken from <a href="http://www.photodon.com/c/LCD-Protective-Films.html">Photodon</a>)</i></span></td></tr>
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While some may dub an anti-glare film to be "anti-reflective", in truth it still reflects all light shining on it. High gloss surfaces will reflect light in the same angle as the source but in opposite direction. This phenomenon is known as <b><span style="color: orange;">specular reflection</span></b>, and is what we usually relate to the law of optical reflectance as learned from science and engineering classes.</div>
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What most of us are unaware of is the fact that no surface is perfectly even, and this unevenness plays havoc on light reflection. The light rays still reflect according to the law which we know, but due to the irregularity of the surface, not all rays bounce towards a user standing at the same angle but opposite direction of the light source. The more irregular the surface is, the rougher it feels to the touch and less number of rays reflects to the said user. The rays reflected off somewhere else contributes to <b><span style="color: orange;">diffuse reflection</span></b>.</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td><a href="http://3.bp.blogspot.com/-d7ufoW07Utg/T9zTQwhf0VI/AAAAAAAAAKQ/iv2Q7MV-9Kk/s1600/Gloss2.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://3.bp.blogspot.com/-d7ufoW07Utg/T9zTQwhf0VI/AAAAAAAAAKQ/iv2Q7MV-9Kk/s1600/Gloss2.jpg" /></a></td></tr>
<tr><td class="tr-caption" style="font-size: 13px;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>Specular and diffuse reflection explained. (image from <a href="http://en.wikipedia.org/wiki/Gloss_(material_appearance)">Wikipedia</a>)</i></span></td></tr>
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With this in mind, it is easy to revisit the question of how the mind defines gloss. <b><u>A surface with perfectly high gloss level will behave like a mirror</u></b> - <b><u>almost all the rays are reflected through <span style="color: orange;">specular reflection</span>.</u></b> It reflects all incident rays of light along the same angle but in an opposite direction. The reflected image will be sharp and features recognizable. </div>
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<b><u>The less glossy the surface is</u></b> (which means more matte), <b><u>the more rays reflect off as <span style="color: orange;">diffuse reflection</span>.</u></b> Since less rays reach the user through specular reflection, the image is blurred along with reduction of the intensity of the image. There couldn't be perfectly low gloss (or perfect matte), simply because there is no definition of "perfect irregularity". There will always be specular reflection, so the user will always see the reflected light from the source, but instead of the sharp image of a lighting fixture, only an even spread of light is observed over the surface.</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-Fh7saNmyPP8/T9zU0jug8hI/AAAAAAAAAKY/eVfAv6aEWs8/s1600/giovannoni_mouse_01.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="422" src="http://2.bp.blogspot.com/-Fh7saNmyPP8/T9zU0jug8hI/AAAAAAAAAKY/eVfAv6aEWs8/s640/giovannoni_mouse_01.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>Although there isn't any distinct image reflected off the surface in these Giovannoni "Mouse" bags, the lighting reflected off the left, high gloss bag shows more distinct border between the light and the dark areas. The right, matte bag has no discernible borders of where the light and dark areas end, only a smear of gradual merging of both. (image taken from <a href="http://www.designboom.com/weblog/cat/8/view/15469/stefano-giovannoni-mouse-for-fabbricapelletteriemilano.html">Design Boom</a>)</i></span></td></tr>
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For qualitative judgment, such as how we judge visually whether a car surface is glossy or matte, <b><u>the observant should focus on the reflected image off the surface</u></b>, not the surface itself. The crisper the reflected image is, the higher the gloss level is. But this could become a problem for quantitative judgment, which all engineers are required to conduct. For this, a glossmeter will be required, as will be discussed next.</div>
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Source: </div>
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<ol>
<li><a href="http://www.gloss-meters.com/GlossIntro.html">Glossmeters</a></li>
<li><a href="http://en.wikipedia.org/wiki/Gloss_(material_appearance)">Wikipedia: Gloss</a></li>
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<br /></div>Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com0tag:blogger.com,1999:blog-4259970604941160665.post-68434274808781177062012-06-20T04:15:00.000-07:002012-06-20T04:15:00.871-07:00Gloss - A Perception of Surfaces Part 1<div style="text-align: justify;">
You take a look at the shiny metallic surface of a sleek sports car and you immediately thought of it as "glossy". You saw another car with a body which reflects none of the ambient lighting, absorbing everything like a black hole, and you think of it as "matte".</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-7GWJ4F_thXo/T9RstmnDnRI/AAAAAAAAAJk/VHpEF0BfK1Y/s1600/mtm_Audi_TT.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="512" src="http://4.bp.blogspot.com/-7GWJ4F_thXo/T9RstmnDnRI/AAAAAAAAAJk/VHpEF0BfK1Y/s640/mtm_Audi_TT.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>The glossy surface of an Audi TT (image taken from <a href="http://nxxos.deviantart.com/art/mtm-Audi-TT-Wallpaper-2-81325733">DeviantArt</a>).</i></span></td></tr>
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As easy as the word comes to your mind, how does one define "glossy"? This would be important to an engineer, since there has to be some way to control the quality of a surface, and control will not be possible without measurement, and no measurement without a solid definition.</div>
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I found that <a href="http://www.gloss-meters.com/GlossIntro.html">Glossmeters.com</a> gave a decent definition of <b><span style="color: orange;">gloss</span></b> - it is <b><u>an attribute of surfaces which causes them to have shiny or lustrous metallic or matte appearance</u></b>. The more direct light is reflected off a surface, the glossier it is to our perception. In other words, glossiness is a <b><u>visual</u></b> perception and <b><span style="color: orange;">gloss effect</span></b> is the outcome of the <b><u>interaction of light with the surface</u></b> in question.</div>
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In order to view how users usually perceive something as glossy or matte, you could take a car body's surface to illustrate this difference in perception. If the body reflects the details of its environment clearly, it is glossy. In other words, <b><u>a mirror is a perfect example of gloss finishing</u></b>. The more the surface is matte, the blurrier the details of reflection, with lines not as clear and contrast not as good.</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-7EFRpHFsqbk/T9R69mQfIlI/AAAAAAAAAJw/Tq-C7MrpjaU/s1600/matte_gloss.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="220" src="http://2.bp.blogspot.com/-7EFRpHFsqbk/T9R69mQfIlI/AAAAAAAAAJw/Tq-C7MrpjaU/s640/matte_gloss.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>A good visual comparison between matte and glossy surface (image taken from <a href="http://www.acer-laptop-screen.co.uk/acer-aspire-5535-15-6-replacement-lcd-laptop-screen.html">Replacement Laptop Screens</a>).</i></span></td></tr>
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While this serves as a general definition for glossiness, the term itself differs between different industry. A surface considered glossy to a paper manufacturer is still too matte for automotive finishing considerations. Different observant may have different perception on gloss comparison as well - some observant may be more perceptive to differences in gloss than others.</div>
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Both of these facts - different definition of gloss between industries and different ability in gloss perception differentiation - along with a few others to be shared in future articles, reiterates the importance of a point. In order to control the outcome of the surface finishing to meet the intended cosmetic requirement, there should be a way to measure and quantify glossiness.</div>
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Source: <a href="http://www.gloss-meters.com/GlossIntro.html">Glossmeters</a></div>
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<br /></div>Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com0tag:blogger.com,1999:blog-4259970604941160665.post-85038357874138569312012-06-14T01:30:00.000-07:002012-06-14T07:16:35.911-07:00Analog vs Digital<div style="text-align: justify;">
<a href="http://4.bp.blogspot.com/--dTYVDdclmE/T9QlizfGHsI/AAAAAAAAAJM/YezuM0TbXbo/s1600/Matrix-Reloaded-poster.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="320" src="http://4.bp.blogspot.com/--dTYVDdclmE/T9QlizfGHsI/AAAAAAAAAJM/YezuM0TbXbo/s320/Matrix-Reloaded-poster.jpg" width="214" /></a>One might have easily heard this hundreds of times - "We are now entering the realm of the digital age" or something along that line. What does that mean, and how much did "digital" influence our life?</div>
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To put it simply, a <b><span style="color: orange;">digital system</span></b> presents data by using <b><u>discrete or discontinuous values</u></b>. In other words, there are only yes and no, 0 and 1. Or it may be 1, 2, 3, 4 and so on, but nothing is envisioned or accepted between the numbers, so there is no such thing as 1.4 in a discrete system. If the system is 1.1, 1.2, 1.3, 1.4 and so on, then 1.27 is not accepted within the system as well. You get the picture.</div>
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On the other hand, its counterpart, an <b><span style="color: orange;">analog system</span></b>, uses <b><u>continuous values</u></b> for data presentation. Within this system, the data could be divided down infinitesimally. Not satisfied by the data value of 1.2, feeling that it is not accurate enough? Drill deeper and you may get 1.26. Deeper more and you may get 1.257. And so forth the value goes.</div>
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<span style="text-align: justify;">One of the simpler example to illustrate the difference between these 2 systems is the thermometer. An analog thermometer will be that transparent glass stick with silvery mercury within, requiring you to read and try your best to find the closest reading between 2 thin horizontal lines. You know the mercury level stops between 37 and 37.1, but if you capture an image and enhance it, then do some calculation, you may get a more accurate result, say 37.07. Do a more detailed enhancing and maybe you get 37.072. You could never stop drilling deeper for an answer, because you could keep dividing the data down between numbers. The data is </span><b style="text-align: justify;"><u>continuous</u></b><span style="text-align: justify;">.</span><br />
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A digital thermometer will be any one of those sophisticated alien thingie which shows the reading through a LCD display or such. Stuff it into your mouth, your ear or wherever you thinks best, wait for a moment, and beep comes the confirmation of a stable reading. Read the display: 37.1. And that's it. A sure answer without the need to scrutinize between lines for more detailed reading, because there aren't any. You will not get 37.15. You get it down to the lowest decimal available and stops there, and so the data is <b><u>discontinuous or discrete</u></b>.</div>
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Seems like a digital system has enhanced our life by making things simpler. So a digital system is just those computer's 0's and 1's right? Actually, no. Human has been using digital systems far longer than the invention of computers. Here are some of the more obvious but less thought of examples:</div>
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<li><b>Alphabets:</b> Well, you couldn't get anything between A and B, or X and Y right?</li>
<li><b>Morse code:</b> Samuel Morse's famous code makes use of binary system's properties by constructing an alphabet through different combinations of long and short dashes.</li>
<li><b>Smoke signals:</b> Smoke signal used by Red Indians is actually an analog-digital conversion. The smoke column is continuous, but by covering the smoke and uncovering it, a digital signal could be generated and the combination of such plumes of discontinuous smoke can be interpreted as a message.</li>
<li><b>Beacons:</b> From ancient ones to modern ones, beacons signaled through a binary system - ON and OFF. </li>
<li><b>Go/No Go gauge:</b> These gauges could be of any type, the most commonly seen will be the pin gauges, with their familiar cylindrical bodies. A hole's size could be checked through these gauges on whether they are manufactured within tolerance. </li>
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Sources: <a href="http://en.wikipedia.org/wiki/Digital">Wikipedia: Digital</a></div>
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<br /></div>Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com1tag:blogger.com,1999:blog-4259970604941160665.post-89557930713900908702012-06-08T19:18:00.003-07:002012-06-08T19:54:16.784-07:00Resin Identification Code<div style="text-align: justify;">
If you were to flip over most everyday items made of polymer, especially those which are disposable, you would have noticed the triangular sign with a number within and maybe some alphabets below. This is the <b><span style="color: orange;">Resin Identification Code</span></b>, and unless you were working with a disposable consumer item and your company is committed to label their product accordingly, you may not have given it a second's thought.</div>
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<tr><td style="text-align: center;"><a href="http://www.flickr.com/photos/holeymoon/1776642673/sizes/o/in/photostream/" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="400" src="http://3.bp.blogspot.com/-Kl64nrAqa_o/T9DF2QFlblI/AAAAAAAAAIo/2OCF8v2EXMg/s400/resin_PET.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>Image taken from Flickr (by <a href="http://www.flickr.com/photos/holeymoon/1776642673/sizes/o/in/photostream/">holeymoon</a>)</i></span></td></tr>
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In order to address the recyclers' rising need for a clear indication of polymer used, Society of Plastics Industry, Inc (SPI) developed and introduced the identification code in 1988. This code is usually found in packaging and containers since these are the main targets of municipal recycling programs, seeing that they are one of common items encountered within residential waste.<br />
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<b><u>The code is used solely to identify the plastic resin in a manufactured item.</u></b> In fact, the triangular label with 3 twisting arrows along with the number within are commonly misinterpreted. The <b><span style="color: orange;">number</span></b> within is an arbitrarily chosen number to represent the target plastics, and has <u><b>nothing to do with ease of recycling</b></u>. A higher number does not mean that the plastics is harder to recycle.<br />
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<b>The Need for Resin Identification Code</b><br />
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So why was there a need for such identification? Isn't it obvious what kind of polymer water bottles are made of? In fact, it isn't. Obvious that is. Disposable water bottles are usually made of PET material, while other bottles meant to be reusable could be fabricated from HDPE, PP or PC. Without the aid of the identification code, a glance at the plastic item will not reveal what the basic plastics is.<br />
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And to know the type of plastics <i>is</i> important to recyclers. Being a recycled plastics doesn't mean that purity is unimportant. In order to get a purer recycled plastics, the collected items need to be sorted first according to their category. By getting the same polymer type together and transformed into recycled plastics, the outcome will have a property that is more predictable.<br />
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Recycled plastics will not have the same property as virgin plastics (that is the original manufactured item from virgin resins) but at least their properties are predictable if they are not mixed with other plastics during recycling. If the property has a manageable tolerance range, recycled plastics can be more easily introduced into engineered products.<br />
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Engineers are mostly concerned with the performance and reliability of the plastics, and a recycled plastics which consists of mixtures of different plastics categories will have a property with much larger tolerance range. This will discourage engineers from choosing recycled plastics, which in turn, limits the use of the latter. All of this translates into a situation where everyone promotes recycled plastics but nobody wants to manufacture items from it because of its unpredictability.<br />
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<b>Voluntary vs Compliance</b></div>
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The development of Resin Identification Code with ASTM International meant that the coding is available for international use through the means of a standards, namely <b><span style="color: orange;">ASTM D7611</span></b>, which was published in 2010. In the US, certain states have adopted the coding system into their legislation, governing the proper labeling of certain products. For engineers working on products which are meant for these areas, it will be prudent make sure that the label meets these requirements.</div>
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In other parts of the world though, the coding could be governed by different legislation or it could be voluntary. It would be interesting to note though, that the coding is specifically mentioned not to influence a consumer's choice of the product, and should be labeled in areas which are inconspicuous, hence the reason why most of them are hidden underneath the bottles.</div>
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Sources:</div>
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<li style="text-align: justify;">Resin Identification Code symbols: <a href="http://www.packaginggraphics.net/plastic-recycle-logos.htm">Packaging Graphics</a> </li>
<li style="text-align: justify;">General explanation: <a href="http://en.wikipedia.org/wiki/Resin_identification_code">Wikipedia</a>, American Chemistry Council (<a href="http://plastics.americanchemistry.com/Plastic-Resin-Codes">here</a> and <a href="http://plastics.americanchemistry.com/Education-Resources/Plastics-101/Plastics-Resin-Codes-PDF.pdf">here</a>), <a href="http://www.plasticsindustry.org/AboutPlastics/content.cfm?ItemNumber=823">SPI</a>, </li>
<li style="text-align: justify;">Problem of mislabeling: <a href="http://earth911.com/news/2010/03/29/mislabeled-plastic-a-new-problem/">Earth911</a> </li>
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</div>Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com0tag:blogger.com,1999:blog-4259970604941160665.post-90570956539448538162012-05-24T08:11:00.000-07:002012-06-07T08:24:49.233-07:00Folding Plug<div style="text-align: justify;">
Ever thought of the fact that however portable and sleek your laptop or latest gadget is, the huge rectangular plug with its 3 bronze pins sticking out totally diminishes the definition of "sleek"? No matter how innovation is done on every part of an electronic device, the plug is the one with almost nonexistent change as far back as anyone could recall.</div>
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<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>Folding Plug can, as its name suggests, be folded and carried with greater mobility (image taken from <a href="http://www.guardian.co.uk/artanddesign/2010/mar/16/folding-plug-wins-design-prize">The Guardian</a>).</i></span></td></tr>
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And I am supremely delighted to know that Min-Kyu Choi of South Korea had designed and reinvented the standard British 3-pin plug into a slimmer version which he dubbed "Folding Plug". His idea was triggered by the fact that Apple's MacBook Air, the world's thinnest laptop to date, has a large electrical plug which tears through whatever is within storage range, including laptop bag's fabric and the laptop itself.</div>
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Folding Plug is designed to be, as its name suggests, foldable in order to increase mobility and storage, while meeting the British Standard regulation at the same time. When the plug is folded, all three pins are aligned in a row, thus achieving the purpose of minimal space consumption. Unfolding the plug and rotating two of its pins will reveal the familiar configurations of British 3-pins plug.</div>
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<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-s8r6oCY2SqU/T7kGkAm7sVI/AAAAAAAAAHo/8wGqowbpkgs/s1600/choi_(uk_folding_plug)09.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="266" src="http://2.bp.blogspot.com/-s8r6oCY2SqU/T7kGkAm7sVI/AAAAAAAAAHo/8wGqowbpkgs/s400/choi_(uk_folding_plug)09.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>The design can easily be fitted into a custom multiple plug holder, as well as one with a USB socket (image taken from <a href="http://www.minkyu.co.uk/Site/Product/Entries/2009/4/20_Folding_Plug_System.html">Minkyu.com</a>.</i></span></td></tr>
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The design won Choi worldwide fame when it was announced as the winner of Brit Insurance Designs of the Year award in 2010. This design goes to show that there is a lot of frustrating problems around us that we have taken for granted and nobody give these a second thought.</div>
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More information regarding the design could be obtained at the below links:</div>
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<li>Mun-Kyu Choi's <a href="http://www.minkyu.co.uk/Site/Product/Entries/2009/4/20_Folding_Plug_System.html">website</a></li>
<li>press coverage from The Guardian: <a href="http://www.guardian.co.uk/artanddesign/2010/mar/16/folding-plug-wins-design-prize">link 1</a> and <a href="http://www.guardian.co.uk/artanddesign/2010/mar/17/folding-plug-design-awards">link 2</a>
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<li>The Method Case <a href="http://www.themethodcase.com/folding-plug-system-min-kyu-choi/">website</a></li>
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<br />Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com0tag:blogger.com,1999:blog-4259970604941160665.post-87817948795959562942012-05-19T04:27:00.002-07:002012-06-08T19:32:21.186-07:00IP Rating - Immersion vs Water Jet<div style="text-align: justify;">
Followers of this series of articles on IP rating will recall that a higher number on the 1st numeral will satisfy the requirements of a lower number (i.e. <b><span style="color: orange;">IP6X</span></b> will mean that it passes all requirements from <span style="color: orange;"><b>IP1X</b></span> to <b style="color: orange;">IP6X</b>, revisit <a href="http://mianengineer2011.blogspot.com/2012/02/ip-rating-dustproof.html">here</a> if the reader is interested). It would be prudent to note that such is not the case for the 2nd numeral.</div>
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<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>An IPX4 test in progress. The semicircle apparatus sprays water through tiny nozzles lining the inner circumference. The apparatus is designed such that the water spray will reach the product from all directions. Notice that the spray is constrained to the top of the product, and the bottom is free from its direct effects (image taken from <a href="http://www.qualilab.it/html/ip_tests.html">Qualilab</a>).</i></span></td></tr>
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The reason behind this is the difference in test requirement: </div>
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<li style="text-align: justify;"><b style="color: orange;">IPX1 to IPX6K,</b> and <b style="color: orange;">IPX9K</b> requires the product to be subjected to a flow of water impacting on the product </li>
<li style="text-align: justify;"><b><span style="color: orange;">IPX7 and IPX8</span></b> requires the product to be immersed in a body of water.</li>
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In order to understand the test requirements, it is essential to first understand the application of the product in an environment prone to water ingress. Water ingress into the product could come in two different scenario - the product could be <u><b>sprayed on by water jets</b></u>, or it could be <b><u>dropped into a body of water for a determinate period of time</u></b>. It is possible to be subjected to both scenarios throughout the product's application lifetime as well.</div>
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<b style="text-align: justify;"><br />Scenario 1: Water spray</b> (<b><span style="color: orange;">IPX1 to IPX6K, IPX9K</span></b>)</blockquote>
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A product may be mounted on a motorcycle, for example, and during its lifetime will be subjected to <b><u>torrential rain</u></b> as well as <b><u>water jets sprayed onto it for cleaning purposes</u></b>. In this case the highest possibility will be a strong jet of water impacting onto the exposed surfaces of the product. </blockquote>
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There could be <b><u>certain surfaces that is protected from the direct impact of the water jet</u></b> due to its position. Such surfaces include the bottom of a casing standing on the ground (the bottom is seated on the ground and water jet could not reach it). </blockquote>
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Affected surfaces are subjected to a <b><u>dynamic pressure</u></b> due to the fact that water jet unleashes the fluid onto the target surface <b><u>at a predetermined rate</u></b>. The scenario remains the same whether the fluid is exerted as a constant spray (<b><span style="color: orange;">IPX3</span></b> to <b><span style="color: orange;">IPX6</span></b>) or as a constant drip (<b><span style="color: orange;">IPX1</span></b> and <b><span style="color: orange;">IPX2</span></b>)</blockquote>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-LHtDAbyIWBc/T7c89h2G6TI/AAAAAAAAAGg/tDCdNlbtUCY/s1600/231072-brussels-firefighters-spray-police-officers-with-freezing-cold-.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="368" src="http://4.bp.blogspot.com/-LHtDAbyIWBc/T7c89h2G6TI/AAAAAAAAAGg/tDCdNlbtUCY/s640/231072-brussels-firefighters-spray-police-officers-with-freezing-cold-.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>A fireman's equipment will always be subjected to strong jets of water during its lifetime, and so would a riot police officer's gear in cases such as the Brussels fireman's union protest in which the protesters (the firemen that is) spray them with strong cold water. In such cases though, the water temperature may play an effect into determining whether water will ingress into the product and damage electronics within (image taken from <a href="http://www.ibtimes.com/articles/297287/20120212/protest-pictures-greece-syria-portugal-egypt-romania.htm">International Business Times</a>).</i></span></td></tr>
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<b> Scenario 2: Immersion </b>(<b><span style="color: orange;">IPX7</span></b> and <b><span style="color: orange;">IPX8</span></b>)</blockquote>
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In other cases, a product may have a high possibility to be subjected to <b><u>immersion within a body of water</u></b> during its lifetime. Certain products or installations claiming to work up to a certain depth underwater are one of these. Handheld products that is supposed to be used near bodies of water, such as a coast guard's two-way radio, are another of those examples. </blockquote>
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Since there are no surfaces that is possibly protected during immersion, <b><u>as long as the surface is exposed, it will be subjected to the effects of water pressure</u></b>. The fluid will try its best to work through nooks and crannies of the product to enter the relatively lower pressure interior. </blockquote>
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<b><u>Static pressure</u></b> is exerted in this scenario as water pressure will not change once certain water depth is attained and the product maintained at that depth, hence an <b><u>unchanged rate of pressure</u></b>. Of course, the pressure is increasing from the moment the product enters the body of water until it reaches the predetermined depth, but the rate of pressure change is considered relatively low and should not be enough to impact the product's sealing.</blockquote>
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-h6mxbyVyrdQ/T7dGpBDHTsI/AAAAAAAAAGs/azEKDB5Q6hk/s1600/m860313_200588_UnderwaterScooter-z1.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="440" src="http://3.bp.blogspot.com/-h6mxbyVyrdQ/T7dGpBDHTsI/AAAAAAAAAGs/azEKDB5Q6hk/s640/m860313_200588_UnderwaterScooter-z1.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>An underwater gear, such as this Underwater Propulsion Scooter, will be subjected to water pressure on all exposed surfaces during its lifetime (image taken from <a href="http://www.sharperimage.com/si/view/product/Underwater-Propulsion-Scooter/200588?question=sea%20scooter">The Sharper Image</a>).</i></span></td></tr>
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The physics affecting both scenarios are vastly different, and as such, a product which meets the immersion requirement (the higher numeral) does not automatically qualifies against the requirements of a water jet requirement (the lower numeral).</div>
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<span style="text-align: -webkit-auto;">The fluid dynamics terms of </span><b style="text-align: -webkit-auto;"><u>static pressure</u></b><span style="text-align: -webkit-auto;"> and </span><b style="text-align: -webkit-auto;"><u>dynamic pressure</u></b><span style="text-align: -webkit-auto;"> are essential to understanding the effects the products are subjected to. A more direct illustration of how a product which meets an immersion requirement may not meet a water jet requirement can be presented through the example of venting membranes.</span></div>
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Most products require air exchange between the interior and the exterior, providing an avenue for hot air to be purged from within. A grill will work in most cases but it is a potential problem for water ingress if the product is subjected to immersion. A venting membrane covering such venting holes is one of the most-used solution, since these membranes allow exchange of air but the surface tension of water halts itself from going past the membrane's surface, sometimes chemically treated to achieve better effect. In other words, the membrane is <b><u>hydrophobic</u></b>. In this case, the membrane will protect the product throughout the <b><u>immersion test</u></b>.</div>
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But the effects of surface tension may not be enough if the membrane is subjected to a <b><u>water jet</u></b>. In this case water may work past the hydrophobic properties of the material and penetrate through. In most cases, products are labeled to meet both water jet and immersion requirements by stating both IP Ratings. So a product meeting <b><span style="color: orange;">IPX4</span></b> and <b><span style="color: orange;">IPX7</span></b> will most probably has this label: <b><span style="color: orange;">IPX4/IPX7</span></b>.</div>
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Sources:</div>
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1. <a href="http://en.wikipedia.org/wiki/IP_Code">Wikipedia</a></div>
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2. <a href="http://australia.rs-online.com/web/generalDisplay.html?id=centre/mro_techref_iprating">RS Online</a></div>
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3. <a href="http://www.flashlightreviews.com/qa/ipxx.htm">Flashlight Review</a></div>
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<br /></div>Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com0tag:blogger.com,1999:blog-4259970604941160665.post-31625130713954533532012-05-05T08:52:00.000-07:002012-06-08T19:32:21.175-07:00IP Rating - Waterproof<div style="text-align: justify;">
Just as it would be difficult to judge the level of protection of "dustproof" products, the same applies to the term "waterproof" - it gives no indication the level of protection the product affords apart from the fact that it is protected against water ingress.</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-RD59-rXhJUw/T6U-_7T7N4I/AAAAAAAAAGI/DKEgVzMeCbc/s1600/waterproof-ipod-stereo-case.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://1.bp.blogspot.com/-RD59-rXhJUw/T6U-_7T7N4I/AAAAAAAAAGI/DKEgVzMeCbc/s320/waterproof-ipod-stereo-case.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>A waterproof iPod Stereo Case - how would you judge the term? Will the casing be free from water ingress if submerged for more than 1 hour? How will an engineer judge the term "waterproof" for critical engineering equipment? (image taken from <a href="http://marineaudio.blogspot.com/2007/10/waterproof-ipod-stereo-case-at.html">Marine Audio and Stereo</a>)</i></span></td></tr>
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The 2nd code element of the IP rating helps shed some light on the level of protection, which is listed in the below table. The technical term usually associated to this code element is "<b><u><span style="color: orange;">protection against liquid ingress</span></u></b>".</div>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-PPDdO1o5Fwk/T6UQmhVKrvI/AAAAAAAAAF8/mVyVsH_qNvg/s1600/Picture3.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="399" src="http://1.bp.blogspot.com/-PPDdO1o5Fwk/T6UQmhVKrvI/AAAAAAAAAF8/mVyVsH_qNvg/s640/Picture3.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>A tabulated detail of IP Rating's 2nd code element.</i></span></td></tr>
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The interpretation of the numeric is similar to that of the 1st code element - an additional "<b><span style="color: orange;">K</span></b>" shows that the level requires pressure, and that the letter "<b><span style="color: orange;">X</span></b>" in the place of the 2nd code element does not mean that it is unprotected, merely untested.</div>
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The range of protection is much larger than that for the 1st code element - it contains level <b><span style="color: orange;">0 to 9K</span></b>. Unlike the 1st code element, the higher protection level does not automatically equate a protection against a lower protection level. A product tested for <b><span style="color: orange;">IPX7</span></b> does not necessarily will pass the test for <b><span style="color: orange;">IPX4</span></b>. The reason behind this logic is due to the difference in the way water interact with the product during test. A separate article is planned for the elaboration on this.</div>
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Just as it is the case for the 1st code element, different application cases call for different level of protection, all of which requires the judgment of the design engineer. An electrical equipment under the possibility of being sprayed with water, such as being placed within a bathroom, may require at least <b><span style="color: orange;">IPX4</span></b> protection. <b><span style="color: orange;">IPX9K</span></b> in particular is developed for road vehicles which require regular intensive cleaning, such as dump trucks and cement mixers.</div>
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The boundary in which the protection is defined may not necessarily be the external compartment - the protection could be designed to only protect the electrical circuitry placed within so that they are isolated from water ingress entering the confinements of the product.</div>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-rAiZRzWtGow/T6VGHMlbirI/AAAAAAAAAGU/eBUh7Zq_eAM/s1600/000_001.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="318" src="http://4.bp.blogspot.com/-rAiZRzWtGow/T6VGHMlbirI/AAAAAAAAAGU/eBUh7Zq_eAM/s400/000_001.png" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>Tough TG-820 iHS - an Olympus camera which claims waterproofing, among other specifications. A glance through the <a href="http://www.olympusamerica.com/cpg_section/product.asp?product=1592&page=specs">specification</a> will show that IP Rating was not used, and instead substituted with "waterproof 10m". Most engineering equipment will not use this in their specification as it tells not the test environment of the waterproofing, such as water temperature, which may be vital to the equipment's performance (image taken from <a href="http://www.olympusamerica.com/index.asp">Olympus website</a>).</i></span></td></tr>
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Sources:</div>
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1. <a href="http://en.wikipedia.org/wiki/IP_Code">Wikipedia</a></div>
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2. <a href="http://australia.rs-online.com/web/generalDisplay.html?id=centre/mro_techref_iprating">RS Online</a></div>
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3. <a href="http://www.flashlightreviews.com/qa/ipxx.htm">Flashlight Review</a></div>
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<br /></div>Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com0tag:blogger.com,1999:blog-4259970604941160665.post-53401382402762643372012-04-10T20:28:00.003-07:002012-04-11T06:34:10.636-07:00What Engineers could learn from the movie "Titanic"<div style="text-align: justify;">
A couple of days ago, I went to see Titanic 3D. This is my second, or maybe third time seeing the movie since 1997/1998 (<span style="font-style: italic;">it’s true, I swear! I know some of you saw it 10 times back then, don’t lie to me ;P</span>). Back then when I was a teenage girl, Titanic did not left any impact on me from the engineering point of view, all I saw was the tormenting love story between star-crossed young lovers, Jack and Rose. Of course, I was like any other teenage girl back then, all doe-eyed for Leonardo DiCaprio.</div>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-8aphRDeWuoI/T4WHwWXx2rI/AAAAAAAAAFo/c2jF-jF-obk/s1600/MV5BMjExNzM0NDM0N15BMl5BanBnXkFtZTcwMzkxOTUwNw@@._V1._SY317_CR0,0,214,317_.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://4.bp.blogspot.com/-8aphRDeWuoI/T4WHwWXx2rI/AAAAAAAAAFo/c2jF-jF-obk/s1600/MV5BMjExNzM0NDM0N15BMl5BanBnXkFtZTcwMzkxOTUwNw@@._V1._SY317_CR0,0,214,317_.jpg" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>Image from<a href="http://www.imdb.com/title/tt0120338/"> IMDb also includes reviews</a>. </i></span></td></tr>
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Alright, this post is not actually about all the gushy-mushy gooey dooey loveyy storeyyy or how cute Leo is, but rather it is about the engineering lessons we could all learn from Titanic (3D or 2D, likewise). <span style="color: red; font-weight: bold;"><br /></span></div>
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<span style="color: red; font-weight: bold;">WARNING:</span> Titanic 3D film spoilers ahead. Do avoid reading if you have not watched the movie yet.</div>
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<span style="font-weight: bold;">Always take serious all warning signs.</span></div>
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In the movie, we see the crew received warning memos (or telegraphs) of icebergs floating in the Atlantic ocean that poses danger to the ship, however all the warnings went unheeded by the Captain (although he did looked quite concerned about it) and the ship’s company Director, Mr Ismay because he believes The Titanic is ‘unsinkable’.</div>
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As an engineer, we should take serious all warning signs and red flags that popped up, even if we don’t see the problem occurring as yet. We should know that prevention is better than cure; designing for reliability is better than designing something ‘just to make it/meet the date’ and do the fire-fighting later if it occurs. It takes a lot of practice, knowledge, experience and wisdom to have foresight of the impending problems, which is why it is important to talk to experienced engineers.</div>
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<span style="font-weight: bold;">Trust your gut instinct and don’t blindly follow orders</span></div>
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Mr Ismay persuaded the Captain to blast the ship full speed ahead so that the Titanic would arrive to New Year earlier than expected and make massive headlines in newspapers, both in the States and Britain. Despite the knowledge that full speed might damage the boilers, Captain EJ Smith still followed instructions. The law of Inertia will not bend, a ship moving at high speed will not have time to swerve away just in time from an iceberg at such a short distance.</div>
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We all know it is great to make headlines and break records, but as a person with more technical knowledge than the rest, one should inform with great seriousness of the concerns and grave dangers of such actions (if there are any) the higher management. Safety always comes first.</div>
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Bigger ain’t always better.</div>
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Everyone who boarded the Titanic and even the owners boasted that RMS Titanic is UNSINKABLE. We all know what happened right? By saying something like that, it has created a ‘false truth’ to everyone that it is unsinkable and when warning alarms were sounded, everyone did not took it seriously at first and thought it was just a ‘drill exercise’.</div>
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I think that all designs; there won’t be anything that doesn’t have any technical weaknesses. There will always be some limit that restricts the operations of your machine/circuit/contraption/etc. Work and stay within the limit, but for something to be great, you must try to push the limits to see what are the areas for improvements so that the next one would be even better.</div>
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Always account for the worst case scenario</div>
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After the iceberg had hit the Titanic, we saw Mr Andrews, the builder of the ship running to the Captain’s room with his blueprints. It seems that he had designed Titanic with cutting-edge hull design that could withstand flooding if 2 of the compartments were filled with water, but unfortunately 5 compartments were already filled with water and it was too late. Titanic is headed towards tragedy in less than 2 hours.</div>
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From this perspective, it was really innovative of Mr Andrews with the hull design. One trait that an engineer must have, innovative. Can’t comment much on this because maybe at that time, 2 hulls with 16 water tight compartment seems full proof enough to be ‘unsinkable’. The question is “To what extent does one has to design to account for the worst?”, this is an engineering judgement that we all must decide upon. Over engineering might increase the cost, being too confident with one’s minimalist design is taking a risk too far.</div>
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Safety trumps style</div>
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In the movie, we saw Mr Andrews taking a group of first class Gentlemen and Ladies on a tour around the ship. Rose mentioned about the number of lifeboats that were too little compared to the number of people aboard the ship. Mr Andrews was very aware of this, but he said because the liner’s management wanted more space for the decks some of the lifeboats had to be taken out.</div>
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And in one of the scenes while the Titanic was slowly sinking, we saw Mr Andrews scolded one of the first class passenger for not wearing a life jacket because it didn’t suit her gown. You’ll be lucky if that black icy Atlantic water matches your gown later, lady.</div>
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Hearing that is already a red flag! Should I explain more?</div>
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Keep calm during moment of distress</div>
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I will never forget how the string quartets kept playing their instruments with sooth sounding music to keep the mood calm and prevent people from panicking. They played right till the very end. The ship’s crew also tried to keep their calm by managing the passengers into lifeboats in orderly fashion (well, they tried).</div>
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From my experience, in moments of distress and pressure, it may seem that fleeing manically seems like the best thing to do in order to survive, but trust me it is not. When facing problems or issues, the best thing to do is first to calm down, then try to put emotional distress aside. Analytically think about what is the root cause of the problem and try to find a solution for the problem. External environment might not be conducive enough to help you stay calm (who could, with all the shouting and screaming from all levels of operations? Lulz!), but just try your best.</div>
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Be brave and take responsibility/accountability</div>
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A lot of people died on that fateful night, including Titanic’s Captain, shipbuilder, crews, passengers and last but not least, Jack Dawson. What I can take from this is that, maybe the Captain, Mr Andrews and the crews decided to stay and go down with the sinking ship because they felt that the accident that happened was their mistake and it was their fault that they failed their responsibilities to bring the ship to New York safely. One of the crew after giving salute to his fellow shipmates, shot himself in the head due to the guilt he felt after shooting a panicky passenger that created havoc while evacuating the ship. Some passengers decided to leave behind because if they’re saved that would mean one less seat left for other souls (namely women and children are of priority) on the lifeboat. Most who decided stayed behind were brave men and old people. Jack sacrificed himself in order to save Rose’s life. If he had climbed onto the plank together with Rose, both wouldn't have made it.</div>
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When something bad happens, it’s always easy to find blame and fault in other people. Maybe that’s our human survival instinct, perhaps, I might be wrong. Finding blame in others is a negative quality to have because it will cause distress and also reduces one’s confidence and image. To be a strong team/unit, we have to bound together and support each other. What could be worse than taking accountability for your mistakes? Be brave and do the right thing.</div>
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Author's note: All these lessons were <u>solely</u> based on the movie itself and I did not do any extensive research to support any claims (sorry if this has created any injustice historical facts). </div>
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So, there you go, 7 long winded lessons. I could go on and on, like the theme song itself but maybe stopping here would be for the best. Did I made you want to watch Titanic in 3D or not?</div>
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And as for the movie review: I would highly recommend you to go and watch Titanic 3D because the visuals and the sounds are even much more better than it was 15 years ago. It felt almost real and you will feel like you're freezing to death in the icy waters of the Atlantic ocean. Even though 3 hours and 20 minutes is such a long time to be wearing bulky and heavy 3D glasses<span style="font-style: italic;"> (it almost made a dent on my nose and between the ears!)</span>, it is actually quite practical to hide your swollen eyes and tears. Thank you James Cameron for making me feel like a teenage girl again.</div>
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PS: Please do not expect Titanic to be anything like Avatar.</div>
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<br /></div>Miss DIYhttp://www.blogger.com/profile/12466337036387989804noreply@blogger.com1tag:blogger.com,1999:blog-4259970604941160665.post-85977445346129883452012-04-03T08:48:00.002-07:002012-06-07T08:24:49.220-07:00Virtual Sky - Working under an Open Sky<div style="text-align: justify;">
Do you feel happy working under a clear blue sky as opposed to working in a stark office environment? Are your office employees shuffling around like zombies, or nodding off to a sleepy start in the conference room during meetings? Then fear not, for Virtual Sky will improve your employees productivity by providing them a chance to work under the infinite horizon of a clear blue sky! Or so that is how it goes...</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-nwDqquA3Mjo/T3sHG3W1kRI/AAAAAAAAAFI/Q1-5O2sIAoY/s1600/Everyday_Im_Shuffling.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="236" src="http://1.bp.blogspot.com/-nwDqquA3Mjo/T3sHG3W1kRI/AAAAAAAAAFI/Q1-5O2sIAoY/s400/Everyday_Im_Shuffling.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>This is how I work ever day (not the Party Rock way...)</i></span></td></tr>
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Reading a recent news article from the technology section, I went in search for more information regarding this new innovation. Developed by Stuttgard-based Fraunhofer Institute for Industrial Engineering, or IAO in short (<i>Institut fur Arbeitswirtschaft und Organisation</i>) and exhibited in CeBIT Trade Fair in Hannover in March 6-12, 2012 was a matrix of ceiling lighting panels simulating clouds moving across a clear sky.</div>
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<b>The Dynamics of Lighting</b><br />
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In fact that is the purpose of the design: to recreate the subtly changing lighting conditions of a cloudy sky. Changes in the light spectrum will occur in a cloudy day mainly due to the movement of clouds across the sky, and a study from that institute found that this dynamic change in lighting conditions heightens awareness and hence improve productivity.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-zVU4pxQrlnI/T3sQlEWTrnI/AAAAAAAAAFY/oUE_fxL1mMU/s1600/rn1_fo1_g_sky-light-sky-bright-in-the-office.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="310" src="http://1.bp.blogspot.com/-zVU4pxQrlnI/T3sQlEWTrnI/AAAAAAAAAFY/oUE_fxL1mMU/s640/rn1_fo1_g_sky-light-sky-bright-in-the-office.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>A dynamic lighting condition recreated through Virtual Sky will promote concentration and heighten alertness (image taken from <a href="http://www.fraunhofer.de/en/press/research-news/2012/january/sky-light-sky-bright.html">Fraunhofer website</a>).</i></span></td></tr>
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Having said that, the flickering of a broken fluorescent light is annoying as hell, and that is a dynamic light-changing condition right? In fact, the dynamic changes in Virtual Sky is subtle, with the frequency set right enough so that it will fluctuate enough to promote concentration and heighten alertness yet imperceptible to the eye.<br />
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It seems too that rapid fluctuations are more preferred than a lazy change in lighting conditions as was reported in <a href="http://www.wired.co.uk/news/archive/2012-01/04/office-ceilings-made-to-mimic-the-sky">Wired</a>. Well, as long as it is not flickering like a fluorescent lamp gone bad, I guess...</div>
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<b>The Technology Behind</b><br />
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As an engineer who had worked with lighting technology before, I couldn't help but wonder what is the key technology behind achieving this. I am of course not wondering how the lighting could be changed - you could achieve that with pre-programmed microcontrollers.<br />
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From what I understand from the official Fraunhofer website, the lighting is achieved through the use of tiles of LEDs, with 288 LEDs per a 50cm x 50cm tile. The use of LED as light source for Virtual Sky's tiles is not surprising, but the key technology is the matte white diffuser film hanging about 30cm below the the light array.<br />
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The diffuser film's importance could not be overstressed because LEDs present themselves as points of light as you would observe in modern traffic lights. This would not be able to recreate a tile that look like a cloud covered sky but with the help of a diffuser, the lighting would spread across more homogeneously and will illuminate a room more effectively.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-LA6M0g6Y9m4/T3sZy_B4hQI/AAAAAAAAAFg/GVQMBiLU3eE/s1600/blueskyonline.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="410" src="http://1.bp.blogspot.com/-LA6M0g6Y9m4/T3sZy_B4hQI/AAAAAAAAAFg/GVQMBiLU3eE/s640/blueskyonline.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>Nothing beats the Monday blues with a different kind of blue... (image taken from <a href="http://techcentral.my/news/story.aspx?file=/2012/3/7/it_news/20120307120019&sec=it_news">TechCentral</a>)</i></span></td></tr>
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The tiles are comprised of 4 types of colored LEDs - blue, red, green and white. The use of these colors will enable the recreation of the full light spectrum and more than 16 million hues. Wait a minute... Doesn't the former 3 colors mix together to create white light? In fact it is not as efficient as using a white LED to add to the hue and brightness of the lighting.<br />
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The prototyped Virtual Sky was developed with 34,560 LEDs spanning an area of 34 square meters and could power up to 3,000 lux at full power. As a reference, 500 - 1,000 lux is enough for comfortable lighting conditions.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-1aHsPonBEzs/T3sH7IEZlyI/AAAAAAAAAFQ/GrZ_dAtPG8U/s1600/blue-sky-and-moon-wallpapers_12484_1280x960.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="480" src="http://2.bp.blogspot.com/-1aHsPonBEzs/T3sH7IEZlyI/AAAAAAAAAFQ/GrZ_dAtPG8U/s640/blue-sky-and-moon-wallpapers_12484_1280x960.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>If my office is going to look like this, I definitely would stop working and just enjoy the scenery... (picture taken from <a href="http://wallpaperstock.net/blue-sky-and-moon-wallpapers_w12484.html">Wallpaperstock.net</a>).</i></span></td></tr>
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<b>Afterthoughts</b><br />
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So how much does this cost? €1,000 per square feet. (@_@)<br />
Who's paying? Your boss.<br />
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So do you think this will be seen in your office anytime soon? I don't think so... Anyway, if they are trying to simulate our Malaysian sunny sky, then I rather stay inside a stark office environment. It may be a blessing to get a sunny sky with clouds floating past lazily in a generally cold country, but the scene of a blue sky in Malaysia only reminds me how hot it is.<br />
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For the interested readers though, here are some links where the technology is reported:<br />
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<ul>
<li><a href="http://www.fraunhofer.de/en/press/research-news/2012/january/sky-light-sky-bright.html">Fraunhofer website</a></li>
<li><a href="http://www.wired.co.uk/news/archive/2012-01/04/office-ceilings-made-to-mimic-the-sky">Wired</a></li>
<li><a href="http://techcentral.my/news/story.aspx?file=/2012/3/7/it_news/20120307120019&sec=it_news">TechCentral</a></li>
<li><a href="http://www.theregister.co.uk/2012/01/04/german_cloud_ceiling/">The Register</a></li>
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<br /></div>Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com2tag:blogger.com,1999:blog-4259970604941160665.post-78324438923217385162012-03-04T06:25:00.000-08:002012-06-07T08:22:13.086-07:00What I "think" do vs. What I "really" do<div style="text-align: center;">
<b>"Hello world"</b></div>
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That phrase is one of the memorable words I learned to program in Computer Programming class. And those exact words is what I would like to greet you all with in my first post here as a guest blogger. I am very much excited to share some of my thoughts and experiences here and I do hope we all could exchange ideas along the way.</div>
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In the past few weeks, we've seen these meme about "What others think I do vs What I actually do..." one too many times. Most of these reproductions are really funny, quite to an extent that it is a chilling truth that we hate to admit.</div>
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(My notes today will talk about electronic engineering in general, but maybe it could relate to other engineering fields.)</div>
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Engineering is a very large field and perhaps not many of our non-engineering friends/relatives would understand the nature of our jobs, unless they don't doze off or look at us with a puzzled face when we start explaining to them what we specifically do in the best of lay-men's terms.</div>
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And with that said, electrical engineering also covers a large spectrum of variety of jobs. In university, I am a power electrical engineering student. Trained as an RF circuit engineer at work and finally moved on as a microelectronic engineering postgrad student. However, my dad still insist in thinking that I have the credibility to do electrical wiring for the whole house.</div>
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Many of us joined the engineering work force with high expectations; working on the latest technology, being part of the innovation and helping the community achieve greater heights with the technology that we provide. It was really a great place to be for fresh graduates who had high hopes and ambition for the whole mankind, like me.</div>
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Then somehow, it seems that the longer you work, the more meetings you had to attend. More time spent on creating presentation slides rather than creating the stuff that you like. We start wishing we had more time to do research or more time to properly sit down to think and analyse our work. Slowly, we start to think that we are surely losing the initial feeling of passion we had last time.</div>
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Maybe the word "Engineer" has been too "Romaticised". We tend to associate engineering with the likes of those great engineers/innovators like Edison, Tesla or maybe Tony Stark. Literature or fiction only highlights the meaningful events of a person's life. I bet these great people also had their fair share of attending dull 2 hour meetings and felt like they don't have enough hours in the day to sort out the thoughts in their head because they're too busy doing side-tasks.</div>
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I guess what I am trying to say here is that (and I know it sounds <i>cliché)</i>, but these dull moments shall pass. How you go through that period of grey skies depends on your attitude, how you manage your time and your productivity levels. If that doesn't work, why wait for something to happen? Instead, be proactive and do something to spark that passion for engineering again.</div>
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Have you ever entered the Engineering field with a certain mindset and only to find out that everything is far from what you expected? Any tips to share on how to fire up the passion of engineering again?</div>
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</div>Miss DIYhttp://www.blogger.com/profile/12466337036387989804noreply@blogger.com0tag:blogger.com,1999:blog-4259970604941160665.post-30802969872995732682012-03-02T07:06:00.000-08:002012-06-08T19:32:21.172-07:00IP rating - IP5KX vs IP6KX<div style="text-align: justify;">
In the previous article, the first numeral code for an IP rating is mentioned as the protection level of a product against intrusion of foreign object, with <b><span style="color: orange;">IP5KX</span></b> and <b><span style="color: orange;">IP6KX</span></b> being the highest level. This article serves to elaborate on the latter requirements and how they differ from each other.</div>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-WfC-984O1a0/T0uoBYt98sI/AAAAAAAAAEs/9U8mNrhsoBQ/s1600/dust_interior.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="480" src="http://1.bp.blogspot.com/-WfC-984O1a0/T0uoBYt98sI/AAAAAAAAAEs/9U8mNrhsoBQ/s640/dust_interior.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>Dust test performed on a laptop within the dust chamber (photo taken from Espec <a href="http://www.espec.com/na/gallery/image_med/154/Settling%20Dust">website</a>).</i></span></td></tr>
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Both protection levels are tested in the same way, except for one difference: the use of underpressure, or vacuum pressure as some has come to call it. In order to test a product's reliability under <b><span style="color: orange;">IP5KX</span></b> or <b><span style="color: orange;">IP6KX</span></b> conditions, it is required to be placed within a test chamber, usually known simply as a dust chamber, continuously for a certain period with circulating talcum powder. It is usual to encounter the term 'talcum powder in suspense' in the place to describe the circulating powder.</div>
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<b>Categories</b></div>
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Unless one had experience in handling, design or certification of products with the aforementioned protection levels, most engineers will be unfamiliar with the category levels of dust test. 2 levels exist for these highest level of protection:</div>
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<li style="text-align: justify;"><b><span style="color: orange;">Category 1 enclosures</span></b> are products in which its normal working cycle involved the possibility of reduction in air pressure within its internal volume to a pressure lower than its surrounding. The product <b><u>must be tested with vacuum pressure</u></b> by maintaining its internal air pressure lower than atmospheric pressure through the use of a vacuum line.</li>
<li style="text-align: justify;"><b><span style="color: orange;">Category 2 enclosures</span></b> are products in which no pressure difference relative to its surrounding air pressure is present. The product need not <b><u>undergo vacuum pressure</u></b> for this category.</li>
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These categories manifest within the protection level in the following method:</div>
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<li style="text-align: justify;"><b><span style="color: orange;">IP6KX</span></b> requires that the product meets <b><span style="color: orange;">Category 1</span></b>. It passes the test if <b><u>no powder is observed</u></b> <b><u>within the internal volume</u></b> of the product. It often falls to the designers to define the confines of the product.</li>
<li style="text-align: justify;"><b><span style="color: orange;">IP5KX</span></b> can be conducted as <b><span style="color: orange;">Category 1</span></b> or <b><span style="color: orange;">2</span></b>. It passes the test if powder is <b><u>not accumulated in a quantity or location such that the correct operation of product is interfered or safety is impaired</u></b>. Note here that powder can exist within as opposed to nonexistence in <b><span style="color: orange;">IP6KX</span></b>.</li>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-uBSBIbNogNc/T0zjMHNkF3I/AAAAAAAAAE0/DIV7bwpvG7o/s1600/ClimaticTesting.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="212" src="http://1.bp.blogspot.com/-uBSBIbNogNc/T0zjMHNkF3I/AAAAAAAAAE0/DIV7bwpvG7o/s640/ClimaticTesting.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>A vacuum line will be required to extract air out from the internal volume of the product if a Category 1 test is to be performed.</i></span></td></tr>
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<b>Category Determination</b></div>
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So why the difference, and how does an engineer judge which category should a product be tested for? The answer lies in the expected working cycle of the product in its environment.</div>
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<li style="text-align: justify;">A product may be subjected to heating from a nearby heater, which introduced <b><u>thermal cycling</u></b> to its internal air volume. This cycling will create a <b><u>pressure difference</u></b> across the confinement of a product, hence a <b><span style="color: orange;">Category 1</span></b> test is required.</li>
<li style="text-align: justify;">Certain products are designed to <b><u>allow airflow</u></b> through the confinements of the product for <b><u>cooling purposes</u></b>. Grills and meshes may be incorporated to limit intrusion of foreign objects but air is otherwise free to flow, hence a <b><span style="color: orange;">Category 2</span></b> test will suffice.</li>
<li style="text-align: justify;">As one of the more severe scenario, a product could be used within a <b><u>potentially explosive atmosphere</u></b>, such as a mining site. Metallic particles may enter the product and drop onto circuit boards, thus creating sparks during short-circuits and igniting the fuel-saturated air. This calls for a <b><span style="color: orange;">Category 1</span></b>, as well as <b><span style="color: orange;">IP6KX</span></b>, requirement (the interested reader in this scenario should refer to the ATEX directive for further information).</li>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-ITqULrscCnA/T0zjjQ5raVI/AAAAAAAAAE8/l8OtYnih1Zc/s1600/japans_nuclear_reactors_under_states_of_emergency-460x307.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="425" src="http://4.bp.blogspot.com/-ITqULrscCnA/T0zjjQ5raVI/AAAAAAAAAE8/l8OtYnih1Zc/s640/japans_nuclear_reactors_under_states_of_emergency-460x307.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>Protective equipment is as essential as this official scanning for radiation in the post-Fukushima disaster, for one who is in close contact with dust tests (picture taken from <a href="http://www.salon.com/2011/03/15/as_japan_quake_nuclear_glance/singleton/">Salon website</a>).</i></span></td></tr>
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<b>Test Method</b></div>
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The test sample is usually hung up or at least placed on a coarse mesh grid to assure that all surfaces are bombarded by the circulating powder evenly. The talcum powder in use is not your everyday talcum - this is a <b><u>specially sized grain</u></b> which needs to be sifted through a calibrated sieve to obtain the proper size.<br />
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Of note though is that this powder is <b><u>harmful to a person's eyes and respiratory system</u></b> as it is very fine, hence proper personnel protection equipment should be donned and training should be conducted to any engineers or technicians working, or even in close contact, with such tests.<br />
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The test duration depends on the test that is performed, and could be either <b><u>8 hours</u></b> or <b><u>80 volumes of air exchanged</u></b>. If the latter is used, then the test duration should not last less than 2 hours. The reason for 2 different test duration definition is due to the product's design and its characteristics during vacuum extraction of its internal air volume.<br />
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<li><b><u>Leaky seal</u></b> may be part of the design intent of a product. When there is a pressure difference, pressure will not buildup since airflow will be generated. In this case, the air exchange test duration should be used. The complex geometry of a product could be simplified into a cuboid or several cuboids for calculation of air volume exchange, and should be simplified towards the worst case (the longer test duration is better than the shorter).</li>
<li><b><u>Tight seal</u></b> will cause little or no airflow generation, hence the negative pressure build. Since no air exchange is going to happen, the product will be tested for 8 hours.</li>
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<i>Sources:</i><br />
1. <a href="http://www.ce-mag.com/archive/06/ARG/bisenius.htm">Compliance Engineering</a></div>
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<br /></div>Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com0tag:blogger.com,1999:blog-4259970604941160665.post-33990930411153963782012-02-25T20:15:00.001-08:002012-06-08T19:32:21.178-07:00IP rating - Dustproof<div style="text-align: justify;">
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<a href="http://2.bp.blogspot.com/-aiA_9Xm_j_E/T0msNVrGMPI/AAAAAAAAAEU/ualXyGr6vvA/s1600/7850_4.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="346" src="http://2.bp.blogspot.com/-aiA_9Xm_j_E/T0msNVrGMPI/AAAAAAAAAEU/ualXyGr6vvA/s640/7850_4.jpg" width="640" /></a></div>
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Instead of claiming a product is 'dustproof', a better way of stating it is '<b><u>protection against foreign object intrusion</u></b>', as is mentioned within IEC60529. There is a reason to it, as a product is not only in danger of being harmed by intrusion of dust or sand. One look at the grills of a table fan and it is not difficult to understand that its purpose is to prevent accidental and intentional (in the case of innocent infants) access to the dangerous rotating blades of the product. </div>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-MZizkUyr0Y0/Tz0unHggUII/AAAAAAAAADw/l_ob27LELV0/s1600/IP_structure.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="468" src="http://1.bp.blogspot.com/-MZizkUyr0Y0/Tz0unHggUII/AAAAAAAAADw/l_ob27LELV0/s640/IP_structure.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>IP rating explained - the 1st code element represents the level of protection against intrusion of foreign objects.</i></span></td></tr>
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The 1st code element of the IP rating system ranges from<b> <span style="color: orange;">0 to 6K</span></b>, and if it is not guaranteed against intrusion of foreign objects, an '<b><span style="color: orange;">X</span></b>' will take its place. The same code element affords protection against both foreign objects and access by persons.<br />
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An item with '<b><span style="color: orange;">X</span></b>' rating does not mean it is unprotected, just that it is not tested for protection against solid material intrusion. The product may be protected to a certain level but the product designers may deem the product not worth the cost to perform the test and have it certified. If a product is proven unprotected against foreign objects, then it will be assigned '<b><span style="color: orange;">0</span></b>' rating.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-1DqXWEC5SsA/T0CDPesnflI/AAAAAAAAAD4/KX4taH5NVaQ/s1600/IP-foreign_object.JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="270" src="http://2.bp.blogspot.com/-1DqXWEC5SsA/T0CDPesnflI/AAAAAAAAAD4/KX4taH5NVaQ/s640/IP-foreign_object.JPG" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>A tabulated detail of IP rating's 1st code element.</i></span></td></tr>
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For a protection of level <b><span style="color: orange;">1</span></b> to <b><span style="color: orange;">4</span></b>, a certain object of diameter no more than the defined should be able to intrude into the product. Say for a <b><span style="color: orange;">IP3X</span></b> product, any foreign objects with diameter more than 2.5mm will not be able to enter the confinements of the product.</div>
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<a href="http://2.bp.blogspot.com/-qzrONLb1izk/T0mt-RZNGeI/AAAAAAAAAEc/EevjzX_rDI4/s1600/dust-storm-hp.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="195" src="http://2.bp.blogspot.com/-qzrONLb1izk/T0mt-RZNGeI/AAAAAAAAAEc/EevjzX_rDI4/s320/dust-storm-hp.png" width="320" /></a>Usually an <b><span style="color: orange;">IP5KX</span></b> and <b><span style="color: orange;">IP6KX</span></b> product is considered securely protected from most everyday objects except very fine particles, with the latter considered as achieving the definition of 'dustproof' or 'dust tight'. Both products need to be tested in a test chamber with circulating dust, and both are tested in the same way but with different pass criteria. A future article is planned with focus and elaboration on <b><span style="color: orange;">IP5KX</span></b> and <b><span style="color: orange;">IPX6KX</span></b> testing.</div>
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The reason why level <b><span style="color: orange;">5</span></b> and <b><span style="color: orange;">6</span></b> are sometimes stated as <b><span style="color: orange;">5K</span></b> and <b><span style="color: orange;">6K</span></b> is that they involved pressure during testing, although this method of rating is not often encountered and should not be confused that they differ from the usual way of stating them as only level <b><span style="color: orange;">5</span></b> and <b><span style="color: orange;">6</span></b>. In other words <b><span style="color: orange;">IP6KX</span></b> is no different from <b><span style="color: orange;">IP6X</span></b> in rating and test method.</div>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-k-HEhLjOJyg/T0mvGr9r6oI/AAAAAAAAAEk/6tezkeMFqWI/s1600/iprating_img02.gif" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="640" src="http://1.bp.blogspot.com/-k-HEhLjOJyg/T0mvGr9r6oI/AAAAAAAAAEk/6tezkeMFqWI/s640/iprating_img02.gif" width="480" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>A copy of the table taken from RS Online website.</i></span></td></tr>
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<i>Sources:</i><br />
1. <a href="http://en.wikipedia.org/wiki/IP_Code">Wikipedia: IP code</a><br />
2. <a href="http://www.flashlightreviews.com/qa/ipxx.htm">Flashlight Reviews</a><br />
3. <a href="http://australia.rs-online.com/web/generalDisplay.html?id=centre/mro_techref_iprating">RS Online</a></div>
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<br /></div>Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com0tag:blogger.com,1999:blog-4259970604941160665.post-48888473121320190412012-02-18T19:00:00.000-08:002012-06-08T19:32:21.182-07:00IP rating - Protection against Ingress<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-8Qmsy5tFncA/TzcoQoyWIkI/AAAAAAAAADg/11rj8eiMp5s/s1600/290310_CybershotTX5_H55_02.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" src="http://3.bp.blogspot.com/-8Qmsy5tFncA/TzcoQoyWIkI/AAAAAAAAADg/11rj8eiMp5s/s1600/290310_CybershotTX5_H55_02.jpg" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>Sony Cybershot TX-5 (image taken <br />from <a href="http://www.sony.com.sg/pressrelease/asset/393808/section/productpressreleases">Sony website</a>).</i></span></td></tr>
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Ever use products that failed because of water seeping into the interior? Or maybe sand jamming the moving parts? It is quite usual for products to be designed to be 'waterproof' or 'dustproof', but as an engineer, how do you know if they really are as they claimed, or what to look out for to know how 'waterproof' it is?</div>
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Engineered items are usually labeled as sealed against dust or water through a system known as IP rating. The IP code labeled on products and claimed in technical datasheet will provide users and buyers <b>the degree of protection provided by mechanical casings and enclosures of electrical equipment</b> against the following:</div>
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<li style="text-align: justify;">protection against<b> foreign objects</b> (e.g. sand and dust)</li>
<li style="text-align: justify;">protection against effects due to<b> ingress of water</b></li>
<li style="text-align: justify;">protection against <b>access</b> (accidental or intentional) by persons to hazardous parts inside the enclosure</li>
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So instead of the term 'waterproof', which provides no information of the nature of the product against water ingress, introduction of the IP rating provides a framework in which user can understand the level of protection afforded by the product against water intrusion.</div>
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<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-QMLXnqPknoc/TzcoseVs25I/AAAAAAAAADo/dbCJX9NlJOg/s1600/Waterproof_Watch_RD76_1_.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://4.bp.blogspot.com/-QMLXnqPknoc/TzcoseVs25I/AAAAAAAAADo/dbCJX9NlJOg/s320/Waterproof_Watch_RD76_1_.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>A waterproof watch<br />(image taken from <a href="http://www.globeoffer.com/4g-30fps-1280960-mini-waterproof-camera-video-watch-pc-camera-p-1574.html">Globeoffer</a>).</i></span></td></tr>
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The details and classification of the rating, along with methods and tests to verify its compliance to a certain rating is outlined by the standard <b>IEC60529</b>, which unfortunately is not available to the public for free. The structure of the IP code is also provided within IEC60529 and it is fortunate that the code structure and method of interpreting it could be found easily from most websites, especially from suppliers of products which need to work under the aforementioned condition. </div>
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IP code usually comprise of at least 4 characters, with additional optional characters to show additional protection. It started off with the mandatory characters 'IP', followed by 2 numerals after it. Each of the latter provides information on intrusion protection, with the 1st numeral providing level of protection against solid particle and the 2nd against water ingress. </div>
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Sometimes additional characters will appear after the 2nd numeral. These characters are optional and rarely used, but will provide additional information regarding the additional type of protection and important details regarding the operation of the product. Subsequent articles will provide more information regarding the interpretation of the numerals and additional characters.</div>
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-MZizkUyr0Y0/Tz0unHggUII/AAAAAAAAADw/l_ob27LELV0/s1600/IP_structure.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="468" src="http://1.bp.blogspot.com/-MZizkUyr0Y0/Tz0unHggUII/AAAAAAAAADw/l_ob27LELV0/s640/IP_structure.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="color: yellow; font-family: Georgia, 'Times New Roman', serif; font-size: small;"><i>IP rating explained.</i></span></td></tr>
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<br /></div>Anonymoushttp://www.blogger.com/profile/13579866543505725752noreply@blogger.com1