Abstract: Carbon nanostructures for use as catalyst supports in hydrogen fuel cells are produced by mixing a carbon material with at least one transition metal such as iron and cobalt, subjecting the mixture thus produced to mechanical grinding, e.g. ball milling in a hydrogen atmosphere for a time sufficient for hydrogen to be absorbed into the mixture, and heating the mixture in an inert atmosphere at a temperature sufficient to crystallize at least one of the carbon material and carbide nanocrystals.

Abstract: A renewable energy (RE) system is disclosed which comprises an energy source providing unit, a DC bus, a buck converter, an hydrogen generator, an hydrogen storage, an energy conversion device, a boost converter, a DC to AC converter, and a monitoring system.

Abstract: A renewable energy (RE) system is disclosed which comprises an energy source providing unit, a DC bus, a buck converter, an hydrogen generator, an hydrogen storage, an energy conversion device, a boost converter, a DC to AC converter, and a monitoring system.

Abstract: The signals to be measured are transformed in the system to discrete time digital signals by synchronous sampling. These digital signals are then processed by a digital signal processor for vector detection and for computing digital feedback sent to the sampling gates. The analyzer has improved characteristics in the area of linearity, drift and test port signal injection because of its highly optimized architecture based on synchronous sampling with digital feedback. It possesses unique characteristics such as the ability to tune to a harmonic or a subharmonic of the excitation frequency and a good sensitivity in a high impedance environment.

Abstract: The disclosure relates to a system for the detection of human presence in hazardous situations near moving machinery; appropriately shaped electrodes are placed in an area to be safeguarded and a radio-frequency signal of appropriate frequency and voltage is applied on the electrodes creating an alternating electric field around them. A bridge circuit is used to measure the capacitive impedance created by the electrodes and a dissipation factor is calculated from the real and imaginary parts of the impedance. If a foreign object is introduced into the electric field, the characteristics of the dielectric are modified creating a change of the value of the dissipation factor. The dissipation of energy in the high frequency region is much greater if this foreign object is a biological tissue as compared to other types of materials, such as conductors or insulators.

Abstract: The invention is concerned with a high-density adsorbent comprising a compacted mass of high surface area carbon particles bound together with a binder and defining a network of substantially unobstructed micropores, the mass of carbon particles having been compacted under a pressure sufficient to cause a reduction of about 50 to about 200% in bulk volume of the mass and a corresponding increase of about 50 to about 200% in density, thereby providing a gas storage capacity increase of about 20 to about 100% over that of the high surface area carbon particles in loose or uncompacted form. The high-density adsorbent according to the invention is particularly useful in adsorption storage systems for low-pressure storage of compressed natural gas.

Abstract: A method and apparatus for measuring physical adsorption of a gas by a solid adsorbent are disclosed. Use is made of a capacitance cell in controlled gas flow communication with a sample cell initially under vacuum and containing the solid adsorbent. The capacitance cell is filled with an adsorptive gas at a predetermined pressure and the dielectric constant of the gas at the predetermined pressure is measured to determine a first density value. The gas from the capacitance cell is then allowed to expand into the sample cell for adsorption by the solid adsorbent, whereby an adsorption takes place pressure falls until eqilibrium is established. The dielectric constant of the gas at equilibrium pressure is measured to determine a second density value, and the amount of gas adsorbed by the solid adsorbent is determined from the first and second density values.

Abstract: The unknown capacitor or a standard capacitor are switched, one at a time, in parallel to a frequency setting circuit which sets the frequency of operation. The parallel combination of the unknown capacitor and the frequency setting circuit form a first parallel resonant circuit and the parallel combination of the standard capacitor and the frequency setting circuit form a second resonant parallel circuit. These resonant circuits are part of the feedback network of an oscillator. The bottom ends of the resonant circuits are connected to an instrumentation amplifier for maintaining the bottom ends at vertual ground in order to make three terminal measurements. A frequency meter is provided for measuring the frequency of resonance of the first resonant circuit and the second resonant circuit.

Abstract: A method and an apparatus for the precise determination of the compressibility factor of a gas sample are disclosed. Two grating interferometers are coupled together with one interferometer defining a refractive index interferometer adapted to provide a signal of information related to the refractive index of the gas sample and the other interferometer defining a pressure interferometer adapted to provide another signal of information related to the pressure of the gas sample whereby to permit measurement of the refractive index as a function of pressure. Each interferometer is capable of dividing a linearly polarized monochromatic laser beam into a measuring beam and a reference beam and causing the measuring beam and reference beam to travel along respective optical paths extending in close parallel relationship over predetermined optical path lengths.