Magazine

Quick-disconnect fittings on hoses and bellows can be equipped with sensors to detect leaks and misalignments that cause leaks. Experiments have shown that four types of sensors are effective for this purpose: force sensors, strain gauges, pressure transducers, and microphones. Of these, force...

Three integrated software products are being developed for use in the further development of autopilot systems for reusable launch vehicles (RLVs). The need for these products arises because of the unique nature of RLVs:

Gauges that would measure liquid levels optically have been proposed for use in aircraft fuel tanks. These gauges would contain no moving parts (no floats) and no wiring inside the tanks. Their overall function could be characterized as that of permanently immersed, self-reading dipsticks.

Thermoplastic coupling is a patented welding process that is used to join thermoplastic parts. At the drill press, during a connector design brainstorming session, an engineer at Lucent Technologies' Bell Laboratories inserted a plastic rod into a cavity that was slightly too small in its...

Several modifications of the design and operation of lithium-ion rechargeable electrochemical cells have been proposed to prolong the cycle lives of the cells. As explained below, overdischarge can result in dissolution of a metal current collector in the anode of a cell, with consequent...

A process for precleaning brass and copper parts before processing them further in a clean room includes a brightening chemical treatment in solution of 85 volume percent phosphoric acid, 3 volume percent nitric acid, and 12 volume percent acetic acid. This solution acts rapidly and can be discarded...

Variable-thermal-conduction devices containing shape-memory-alloy (SMA) actuators have been proposed for use in situations in which it is desired to switch on (or increase) thermal conduction when temperatures rise above specified values and to switch off (or decrease) thermal conduction when...

A Luneberg lens is a microwave lens consisting of a series of concentric shells of differing dielectric constants. The highest dielectric constant, or refractive index, resides at the core and the lowest, at the outer shell. Microwaves passing through this arrangement of shells are focused in the...

The Hybrid Electric Vehicle Analysis (HEVA) computer program numerically simulates the performance of an automotive vehicle -- especially a hybrid vehicle. A vehicle is said to be hybrid if (1) it contains an energy-storage device (a battery, flywheel, or ultra-capacitor) that is charged with...

A report discusses experiments on the flow of water along the interior of a transparent rotating cylindrical drum, the interior of which was partitioned into five cavities by disks with central holes and outer edges attached to the cylindrical drum wall. This water-flow model was designed to provide...