Electronics Protection - June/July 2011 - (Page 3)

Editor’s Choice Crenlo Adds NEMA Wall-Mount Enclosures to Emcor Product Lineup Crenlo has introduced NEMA Type 4 and Type 12 wall-mount enclosures to its standard lineup of Emcor enclosures. The NEMA wall-mount enclosures are designed to house and protect critical electrical components such as terminal blocks, electrical controls and instruments from harsh industrial settings. The NEMA type 4 enclosure is built for indoor or outdoor use to protect against the ingress of solid foreign objects (falling dirt and windblown dust) as well as the ingress of water (rain, sleet, snow, splashing water and hose-directed water). The NEMA type 12 enclosure is built for indoor use to protect against the ingress of solid foreign objects (falling dirt and circulating dust, lint and fibers) as well as the ingress of water (dripping and splashing). Both of Crenlo’s NEMA enclosures are fabricated with 14-gauge steel, UL-approved gaskets and continuous welds throughout, providing strength and resistance to external contaminants. Available in a variety of sizes, ranging from 16 by 16 by 6-inch, all the way to 48 by 36 by 12-inch, the enclosures are built for a set of applications. Available accessories include 12 and 16-gauge steel sub-panels, metal print pockets to store manuals and documentation, and locking latches designed for field installation. Carey said. “DMA generally assumes that your material isn’t changing in any permanent way. In the early tests, the software kept telling me, I’d damaged the sample as the stiffness increased. I also had to trick it with an unsolvable program loop to achieve the high number of cycles.” Materials scientists know that metals can strain-harden during repeated deformation, a result of the creation and jamming of defects, known as dislocations, in their crystalline lattice. Polymers, which are made of long, repeating chains of atoms, don’t behave the same way. The team is not sure precisely why the synthetic material behaves as it does. “We were able to rule out further cross-linking in the polymer as an explanation,” Carey said. “The data shows that there’s very little chemical interaction, if any, between the polymer and the nanotubes, and it seems that this fluid interface is evolving during stressing.” “The use of nanomaterials as a filler increases this interfacial area tremendously for the same amount of filler material added,” Ajayan said. “Hence, the resulting interfacial effects are amplified as compared with conventional composites.” They also found one other truth about this unique phenomenon: simply compressing the material didn’t change its properties; only dynamic stress made it stiffer. Both researchers noted this is the kind of research that asks more questions than it answers. While they can easily measure the material’s bulk properties, it’s an entirely different story to understand how the polymer and nanotubes interact at the nanoscale. “People have been trying to address the question of how the polymer layer around a nanoparticle behaves,” Ajayan said. “It’s a very complicated problem. But fundamentally, it’s important if you’re an engineer of nanocomposites. From that perspective, I think this is a beautiful result. It tells us that it’s feasible to engineer interfaces that make the material do unconventional things.” New Material Adapts to Strain Researchers at Rice University have created a synthetic material that gets stronger from repeated stress, much like the body strengthens bones and muscles after repeated workouts. Work by the Rice lab of Pulickel Ajayan, professor in mechanical engineering, materials science and chemistry, shows the potential of stiffening polymer-based nanocomposites with carbon nanotube fillers. The trick, it seems, lies in the complex, dynamic interface between nanostructures and polymers in carefully engineered nanocomposite materials. Brent Carey, a graduate student in Ajayan’s lab, found the interesting property while testing the high-cycle fatigue properties of a composite he made by infiltrating a forest of vertically aligned, multiwalled nanotubes with polydimethylsiloxane (PDMS), an inert, rubbery polymer. To his surprise, repeatedly loading the material didn’t seem to damage it at all. In fact, the stress made it stiffer. Carey, whose research is sponsored by a NASA fellowship, used dynamic mechanical analysis (DMA) to test the material. He found that after 3.5 million compressions (five per second) over about a week’s time, the stiffness of the composite had increased by 12 percent and showed the potential for even further improvement. “It took a bit of tweaking to get the instrument to do this,” Anderson Power Product Expands the Four Position SPEC Pak Connector Series Anderson Power Products (APP) has expanded its four position SPEC Pak family of products to include an Inline Receptacle. The four position SPEC Pak series now includes the Inline Receptacle, Panel Mount Receptacle and Plug for wire-towire and wire-to-panel applications. This IP 68 rated connector achieves this rating by utilizing a size 16 PG style sealing gland, an interfacial sealing gasket that’s incorporated within the plug housing and a latch to secure the connector tight. The UL94 V-0 rated housing is designed to be Touch Safe per the requirements of UL 1977 when used with Finger Proof Powerpole contact housings. The four position SPEC Pak will hold up to four Powerpole power contacts, 16 signal contacts or a combination of both. Individually, the power contacts are rated to 45 amps and are capable of handling wire sizes of 24 to 10 AWG (0.25 to 4 mm²). Ground contacts are first mate/last break. Contact housings, both finger proof and standard, are available in a wide array of colors providing color-coding options and design flexibility. The combination of housings, power, ground and signal contacts offers thousands of design options for the most demanding applications. June/July 2011 www.ElectronicsProtectionMagazine.com 3 http://www.ElectronicsProtectionMagazine.com

Table of Contents for the Digital Edition of Electronics Protection - June/July 2011

New Material Adapts to Strain
XPAL Power Debuts PowerSkin Battery-Boosting Smartphone Cases
Ruggedizing Enclosures: From Military to Seismic to Mobile Applications
The Benefits of Using Thermal Simulation Software in Electronics Design
Designers Face a Potentially Confusing Assortment of Surge Protection Device Choices
Military’s Demands Drive Innovative Thermal Management Solutions
Integra Enclosures Releases new Product to Genesis Line of Enclosures
New LCR COTS Filters Perform in Extended Temperature Range for Added Reliability
Thermacore Introduces VME64x/VPX Cold Plates for Military Cooling Applications
Laird Technologies Expands Thermal Gap Filler Line
ASI New Line of 13mm MCB’s offer UL 1077 Supplemental Protection
New Deutsch HDP Series Electrical Connector
Industry News
Calendar of Events

Electronics Protection - June/July 2011