A refrigeration system in which a pressurized gas provides the energy. The gas is expanded through an expansion engine and then passed through a heat exchanger, wherein the refrigeration effect resulting from its expansion is recovered. The expansion engine operates a conventional closed loop refrigeration system which is, in turn, cascaded through the low temperature gas discharging from the expansion engine. Prior to being cooled by the low temperature gas, the refrigeration cycle may also rej...

A low fluid pressure check valve with a one-piece body having a supple diaphragm with a pair of integral spaced lugs extending from one face thereof. A pair of flexible lips of an oval shaped tube which is integral with the diaphragm extend between the lugs to provide a fluid passage through the body of the valve. Displacement of the diaphragm moves the free ends of the lugs toward and away from each other to engage and disengage the lips and thereby close and open the fluid passage.

A self-contained, full-film hydrodynamic bearing utilizing (1) the hydrodynamic properties of a ferrofluid (colloidal suspension of magnetic particles) to produce support pressures in the bearing by an applied viscous pumping action, and (2) the magnetic properties of the ferrofluid to retain the fluid within the bearing.

A method and apparatus for recoding a sequence of binary digits into a form having lower disparity for transmission and the transformation of the data back into its original form are described. In recoding, successive groups of n binary digits are recoded as groups of m binary digits, where m is greater than n, and both are positive integers. Recoding is arranged so that some but not all of the groups of m digits have minimum disparity and successive groups of m digits having nonzero disparity h...

A reduced zinc oxide-copper oxide low-temperature shift catalyst is prepared that contains colloidal silica and diatomaceous earth. The resulting catalyst has improved pore, density and strength characteristics.

Apparatus forms a reflective subject hologram for use with a source of heterochromatic light in the subsequent reconstruction process. The apparatus provides for causing the rays reflected from the subject to interfere with reference rays, at the holographic surface, at a low angle. The low angle is formed by projecting a divergent laser beam through the surface of the hologram, the reference rays being subsequently retroreflected to the hologram surface to interfere with the rays reflected from...

A follower amplifier which connects a variable and noisy power source to a load obtains its reference from a divider composed of two serially connected transistors using feedback to obtain two widely different ratios of dynamic resistance to average resistance.

A low liquid level indicator particularly adapted for use in an automotive vehicle which includes a probe adapted to complete an electrical circuit to the container of the liquid when the liquid is at a satisfactory operating level. A bimetallic pulse-producing means is connected to the source of electrical energy for the vehicle thereby cyclically coupling the source of electrical energy to the probe through an AC coupling means. A voltage divider is formed by means of a resistor and the impeda...

A stilt that is adjustably repositioned to a high or a low position for use, with adaptability and capability of use with various sized shoes of the user, and in which falling or losing or shifting of the user's balance is substantially eliminated.

A spark drill for subterranean drilling is disclosed which may be attached to a standard or continuous drill string. The drill is characterized by multiple electrodes having a layer of semiconductor material between them which provides an electrical shunt path and further includes a trigger circuit for initiating the spark.