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The Fast Guide to Protecting COTS Electronics with Conformal Coatings: The Basics of Acrylic, Silicone, Urethane and Parylene Conformal Coatings

Commercial off-the-shelf (COTS) electronics are used frequently for military and aerospace applications. They need to provide unquestionable performance, operating without fail under often extreme, severe, and rugged circumstances for extended periods of time. Some COTS applications that demand solutions superior to normal use are:

Posted in: White Papers, White Papers, Coatings & Adhesives

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Solving the Challenges of Grounding and Bonding Composite Airframes

Weight-saving composite airframes create new challenges in providing reliable grounding and bonding systems.

Posted in: On-Demand Webinars, Composites

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Regenerable Trace-Contaminant Sorbent for the Primary Life Support System (PLSS)

This technology has applications in air-revitalization systems on spacecraft, submarines, automobiles, and commercial aircraft. Lyndon B. Johnson Space Center, Houston, Texas The NASA objective of expanding the human experience into the far reaches of space requires the development of regenerable life support systems. This work addresses the development of a regenerable air-revitalization system for trace-contaminant (TC) removal for the spacesuit used in extravehicular activities (EVAs). Currently, a bed of granular activated carbon is used for TC control. The carbon is impregnated with phosphoric acid to enhance ammonia sorption, but this also makes regeneration difficult, if not impossible. Temperatures as high as 200 °C have been shown to be required for only partial desorption of ammonia on time scales of 18,140 hours. Neither these elevated temperatures nor the long time needed for sorbent regeneration are acceptable. Thus, the activated carbon has been treated as an expendable resource, and the sorbent bed has been oversized in order to last throughout the entire mission.

Posted in: Briefs, TSP

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Lithium Fluoride as a Polysulfide Shuttle Inhibitor for Lithium Sulfur Chemistry

This invention imparts properties such as reinforcement, enhanced tensile strength, and/or electrical and thermal conductivity to composites. Lyndon B. Johnson Space Center, Houston, Texas In a lithium sulfur cell, the reduction of sulfur to lithium sulfide is a critical series of reactions that provides a large theoretical capacity of 1,672 mAh/g sulfur. One of many challenges in this system is the solubility of generated lithium polysulfides during the charge/discharge process. These polysulfides derived from the reduction of elemental sulfur are soluble in organic electrolytes, and can be reduced at the anode, causing an undesired reaction. Polysulfide species can also accumulate at the surface of the cathode and be further reduced to lower-order polysulfides such as Li2S2 or Li2S. The insulating nature of these lower-order polysulfides blocks the electron pathway on the carbon cathode.

Posted in: Briefs, TSP

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Fibers of Aligned Single-Wall Carbon Nanotubes and Process for Making the Same

This invention imparts properties such as reinforcement, enhanced tensile strength, and/or electrical and thermal conductivity to composites. Lyndon B. Johnson Space Center, Houston, Texas Single-wall carbon nanotubes (SWNTs) are fullerenes of closed-cage carbon molecules typically arranged in hexagons and pentagons. Commonly known as “buckytubes,” these cylindrical carbon structures have extraordinary properties, including high electrical and thermal conductivity, as well as high strength and stiffness. With intrinsic strength estimated to be on the order of 100 times that of steel, SWNTs are a possible strengthening reinforcement in composite materials. The intrinsic electronic properties of SWNTs also make them electrical conductors and useful in applications involving field mission devices such as flat-panel displays, and in polymers used for radio frequency interference and electromagnetic shielding that require electrical conductance properties.

Posted in: Briefs

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Enhancing MRI Contrast by Geometrical Confinement of Small Imaging Agents Within Nanoporous Particles

Lyndon B. Johnson Space Center, Houston, Texas Magnetic resonance imaging (MRI) has evolved into one of the most powerful, non-invasive diagnostic imaging techniques in medicine and biomedical research. The superior resolution and in-depth anatomical details provided by MRI are essential for early diagnosis of many diseases. Chemical contrast agents (CAs) have been widely used for improving the sensitivity and diagnostic confidence in MRI.

Posted in: Briefs

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Bonded Magnets: A Versatile Class of Permanent Magnets

Permanent magnets are ubiquitous in modern societies. Devices which use permanent magnets include motors, sensors, actuators, acoustic transducers, etc. These are used in home appliances, speakers, office automation equipment, aerospace, wind turbine generators, medical laboratory diagnostic test equipment, and more. It is estimated, for example, that a typical automobile uses up to 120 permanent magnets in windshield wipers, starter motors, seat adjusters, door lock actuators, fuel pumps, sensors, gauges, etc. The development of Hybrid Electric Vehicle and Electric Vehicle drive technologies has been greatly enhanced by the availability of high performance magnetic materials.

Posted in: White Papers, Coatings & Adhesives

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White Papers

Performance Characteristics of Digital Frequency Discriminators
Sponsored by Wide Band Systems
VINCENT Systems Prosthetics Give Patients A New Feel For Life
Sponsored by HP
How to Select an Analog Signal Generator
Sponsored by rohde and schwarz a and d
The Benefits of Integrated Video Management
Sponsored by Curtiss Wright
Reverse Engineering
Sponsored by Servometer
Sterilization of Medical Equipment
Sponsored by master bond

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