Direct methanol fuel cells integrated with fuel reservoirs have been proposed as power sources in applications that involve power demands up to about 50 W. A prior concept of direct methanol fuel cells as alternatives to re- chargeable batteries in such applications was reported previously in...

High-performance lithium-ion electro- chemical cells and batteries have been developed to satisfy a need for longer lifetimes and greater capacities in the power supplies of the life-support systems attached to space suits. These and similar cells and batteries could also be used on Earth to satisfy...

The fractional calculus (which admits of integrals and derivatives of non-integer order) dates back almost to the origin of the better-known ordinary (integer-order) calculus, but thus far has been treated more as a mathematical curiosity than as a scientific and engineering tool. Increasingly many physical processes...

A magnetostrictive motor and its drive circuit and control system have been designed to be especially suitable for robotic applications in which there are requirements for precise, high-force linear actuators. The motor includes a laminated armature made of the magnetostrictive alloy...

An improved charge-termination technique has been developed to obtain a more accurate balance between charge and discharge of rechargeable lithium-ion-based electrochemical cells and batteries. The technique has been demonstrated experimentally and is now in use in a laboratory battery...

Some improvements have been made in an instrument designed expressly for recording lightning-induced transient voltages on power and signal cables. The instrument as it existed prior to the improvements was described in "Fast Transient-Voltage Recorder" (KSC-11991), NASA Tech Briefs, Vol. 23, No....

A solar-powered vapor-compression refrigeration system developed for Johnson Space Center operates without batteries. The design of this system will make the cost of solar-powered refrigeration systems competitive and enable the use of such systems in long-distance spaceflights, military field...

A computer program performs a unified analysis of the radiation exposure, the temperatures, and the power generation and distribution for predicting the performance of the TOPEX satellite on orbit and during maneuvers. The unified analysis is needed because all aspects are...

Weighing scales (e.g., kitchen and bathroom scales) of a proposed type would incorporate sensory devices like the one described in "Low-Power, Microprocessor-Controlled Strain-Gauge Circuit" (NPO-19750), NASA Tech Briefs, Vol. 21, No. 1 (January 1997), page 45. Unlike other weighing scales...

The feasibility of a capacitive sensor for measuring the level of liquid nitrogen in a container has been demonstrated. The basic sensor design could also readily be adapted to measurement of the levels of cryogenic liquids other than nitrogen.

An instrumented buoy measures selected aspects of the spectrum of upwelling light for assessment of "water quality." The buoy carries a previously patented optical-backscatter probe that contains a hyperspectral sensor. The output of the probe is processed by a small onboard computer....