Special Coverage

Supercomputer Cooling System Uses Refrigerant to Replace Water
Computer Chips Calculate and Store in an Integrated Unit
Electron-to-Photon Communication for Quantum Computing
Mechanoresponsive Healing Polymers
Variable Permeability Magnetometer Systems and Methods for Aerospace Applications
Evaluation Standard for Robotic Research
Small Robot Has Outstanding Vertical Agility
Smart Optical Material Characterization System and Method
Lightweight, Flexible Thermal Protection System for Fire Protection

Photochemically Synthesized Polyimides

Single monomers are polymerized by exposure to ultraviolet light, without heating. An alternative to the conventional approach to synthesis of polyimides involves the use of single monomers that are amenable to photopolymerization. Heretofore, the synthesis of polyimides has involved multiple-monomer formulations and heating to temperatures that often exceed 250 °C. The present alternative approach enables synthesis under relatively mild conditions that can include room temperature.

Posted in: Briefs, TSP, Materials, Forming, Productivity, Polymers


Hydroxide-Assisted Bonding of Ultra-Low-Expansion Glass

Preparation of bond surfaces is critical to success. A process for hydroxide-assisted bonding has been developed as a means of joining optical components made of ultra-low-expansion (ULE) glass, while maintaining sufficiently precise alignment between. The process is intended mainly for use in applications in which (1) bonding of glass optical components by use of epoxy does not enable attainment of the required accuracy and dimensional stability and (2) conventional optical contacting (which affords the required accuracy and stability) does not afford adequate bond strength.

Posted in: Briefs, Materials


Optimized Carbonate and Ester-Based Li-Ion Electrolytes

This technology can be used in portable electronics, cell phones, and electric vehicles. To maintain high conductivity in low temperatures, electrolyte co-solvents have been designed to have a high dielectric constant, low viscosity, adequate coordination behavior, and appropriate liquid ranges and salt solubilities. Electrolytes that contain ester-based co-solvents in large proportion (>50 percent) and ethylene carbonate (EC) in small proportion (<20 percent) improve low-temperature performance in MCMB carbon-LiNiCoO2 lithium-ion cells. These co-solvents have been demonstrated to enhance performance, especially at temperatures down to –70 °C. Low-viscosity, ester-based co-solvents were incorporated into multi-component electrolytes of the following composition: 1.0 M LiPF6 in ethylene carbonate (EC) + ethyl methyl carbonate (EMC) + X (1:1:8 volume percent) [where X = methyl butyrate (MB), ethyl butyrate EB, methyl propionate (MP), or ethyl valerate (EV)]. These electrolyte formulations result in improved low-temperature performance of lithium-ion cells, with dramatic results at temperatures below –40 °C. [See “Ester-Based Electrolytes for Low-Temperature Li-Ion Cells,” (NPO-41097) NASA Tech Briefs, Vol 29, No. 12 (December, 2005), p. 59.]

Posted in: Briefs, TSP, Materials, Optimization, Lithium-ion batteries, Electrolytes, Materials properties


Ultrasonic/Sonic Impacting Penetrators

Soil can be probed relatively gently to a depth of several feet. Ultrasonic/sonic impacting penetrators (USIPs) are recent additions to the series of apparatuses based on ultrasonic/sonic drill corers (USDCs). A USIP enables a rod probe to penetrate packed soil or another substance of similar consistency, without need to apply a large axial force that could result in buckling of the probe or in damage to some buried objects. USIPs were conceived for use in probing and analyzing soil to depths of tens of centimeters in the vicinity of buried barrels containing toxic waste, without causing rupture of the barrels. USIPs could also be used for other purposes, including, for example, searching for pipes, barrels, or other hard objects buried in soil; and detecting land mines.

Posted in: Briefs, TSP, Mechanical Components, Mechanics


Miniature, Lightweight, One-Time-Opening Valve

A small solder plug is melted to release a pressurized gas. The figure depicts the main parts of a prototype miniature, lightweight, one-time- opening valve. Like some other miniature one-time-opening valves reported in previous issues of NASA Tech Briefs, this valve is opened by melting a material that blocks the flow path. This valve is designed to remain closed at some temperature between room temperature and cryogenic temperature until the time of opening.

Posted in: Briefs, TSP, Mechanical Components, Mechanics


Supplier Management System

Supplier Management System (SMS) allows for a consistent, agency-wide performance rating system for suppliers used by NASA. This version (2.0) combines separate databases into one central database that allows for the sharing of supplier data. Information extracted from the NBS/Oracle database can be used to generate ratings. Also, supplier ratings can now be generated in the areas of cost, product quality, delivery, and audit data. Supplier data can be charted based on real-time user input. Based on these individual ratings, an overall rating can be generated.

Posted in: Briefs, Information Sciences, Data exchange, Data management, Supplier assessment


Improved CLARAty Functional-Layer/Decision-Layer Interface

Improved interface software for communication between the CLARAty Decision and Functional layers has been developed. [The Coupled Layer Architecture for Robotics Autonomy (CLARAty) was described in “Coupled-Layer Robotics Architecture for Autonomy” (NPO-21218), NASA Tech Briefs, Vol. 26, No. 12 (December 2002), page 48. To recapitulate: the CLARAty architecture was developed to improve the modularity of robotic software while tightening coupling between planning/execution and basic control subsystems. Whereas prior robotic software architectures typically contained three layers, the CLARAty contains two layers: a decision layer (DL) and a functional layer (FL).] Types of communication supported by the present software include sending commands from DL modules to FL modules and sending data updates from FL modules to DL modules.

Posted in: Briefs, TSP, Information Sciences, Architecture, Computer software and hardware, Robotics


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