Abstract: A system for analysis of trace concentrations of contaminants in air includes a portable liquid chromatograph and a preconcentrator for the contaminants to be analyzed. The preconcentrator includes a sample bag having an inlet valve and an outlet valve for collecting an air sample. When the sample is collected the sample bag is connected in series with a sorbing apparatus in a recirculation loop. The sorbing apparatus has an inner gas-permeable container containing a sorbent material and an outer gas-impermeable container. The sample is circulated through the outer container and around the inner container for trapping and preconcentrating the contaminants in the sorbent material. The sorbent material may be a liquid having the same composition as the mobile phase of the chromatograph for direct injection thereinto.

Abstract: A power source and related methods comprise a slurry-type reactive metal anode containing such metal as aluminum, lithium, sodium, calcium or magnesium, or alloys or mixtures of such metals, suspended in a flowing aqueous electrolyte, in conjunction with a water-consuming hydrogen-evolving cathode in an electro-chemical reactor cell, so as to generate electrical power from the metal-water reaction. The hydrogen evolving from said cell may be fed to a hydrogen-consuming fuel cell or battery to yield additional electrical energy.

Abstract: A portable instrument for use in the field in detecting and identifying a hazardous component in air or other gas including an array of small sensors which upon exposure to the gas from a pattern of electrical responses, a source of standard response patterns characteristic of various components, and microprocessor means for comparing the sensor-formed response pattern with one or more standard patterns to thereby identify the component on a display. The number of responses may be increased beyond the number of sensors by changing the operating voltage, temperature or other condition associated with one or more sensors to provide a plurality of responses from each of one or more of the sensors. In one embodiment, the instrument is capable of identifying anyone of over 50-100 hazardous components.

Abstract: A method and instrument including an electrochemical cell for the detection and measurement of methane in a gas by the oxidation of methane electrochemically at a working electrode in a nonaqueous electrolyte at a voltage about about 1.4 volts versus R.H.E. (the reversible hydrogen electrode potential in the same electrolyte), and the measurement of the electrical signal resulting from the electrochemical oxidation.

Abstract: A power source and related methods comprise a slurry-type reactive metal anode containing such metals as aluminum, lithium, magnesium, calcium or magnesium, or alloys or mixtures of such metals, suspended in a flowing aqueous electrolyte, in conjunction with a water-consuming hydrogen-evolving cathode in an electrochemical reactor cell, so as to generate electrical power from the metal-water reaction. The hydrogen evolving from said cell may be fed to a hydrogen-consuming fuel cell or battery to yield additional electrical energy.

Abstract: Methods and apparatus for the generation of energy from the oxidation of aluminum comprise means for breaking up the continuity of the passivating oxide layer on the aluminum surface by exposing said surface to a mercury-, indium- or gallium-containing substance, exposing the surface-treated aluminum to a fluid which is capable of oxidizing said aluminum, and withdrawing useful energy from the oxidation reaction. The oxidizing fluid may be air, with the energy-withdrawing means a thermal engine, preferably of the closed cycle type. Alternatively, the fluid may be an aqueous electrolyte, preferably a neutral saline, mildly alkaline or mildly acidic solution, with the energy-withdrawing means comprising an electrochemical cell.

Abstract: Methods and apparatus for the generation of energy from the oxidation of aluminum comprise means for breaking up the continuity of the passivating oxide layer on the aluminum surface by exposing said surface to a mercury-, indium- or gallium-containing substance, exposing the surface-treated aluminum to a fluid which is capable of oxidizing said aluminum, and withdrawing useful energy from the oxidation reaction.

Abstract: Methods and apparatus are provided for sensing gases in the environment wherein electrochemical sensing procedures are utilized not only for monitoring ambient continuously for the presence of such gases; but also, for the periodic automatic recalibration and self-adjustment of the sensing instrument, as required, to accommodate changing conditions with time. Such accommodation includes not only changes in the instrument itself, but also changes in the environment affecting the accuracy of the monitoring function. The instrument is connected with a microprocessor, or other information storage or retrieval instrumentation which controls the periodic recalibration by measuring, separately from the monitoring function, the electrochemical response to a sample of the gas being monitored, and by adjusting the subsequent instrument readings to reflect the recalibration. During this recalibration procedure, the instrument can be adjusted to zero reading for accommodating drift, as will be understood.

Abstract: Apparatus and methods for generating heat and electricity from the consumption of a variety of aluminum products comprise:(a) a reaction chamber containing an aqueous electrolyte solution and adapted for introduction therein of aluminum pieces of various shapes and sizes up to a certain maximum predetermined size and for effecting a chemical reaction between said aqueous electrolyte and said aluminum pieces yielding aluminum hydroxide and an intermediate reactant;(b) means for feeding said aluminum pieces into said reaction chamber in small quantities upon demand;(c) means for removing the heat generated in said chamber as a result of said reaction;(d) means for removing said aluminum hydroxide reaction product; and(e) means for oxidizing said intermediate reactant in an electrochemical cell, thereby generating electrical energy.The intermediate reactant is preferably hydrogen or zinc.

Abstract: An electrochemical power generation apparatus and methods of control thereof are described. The power source comprises one or more electrochemical cells having an anode and an oxygen or hydrogen peroxide depolarized cathode, a liquid electrolyte solution, electrolyte circulation means and an electrolyte container. The methods include varying the volumes of electrolyte in said container and in said battery cell so as to control the polarization and hence the cell output voltage of said anode and cathode. The anode is of the consumable-metal type, particularly aluminum. The method of varying the volume may be effected by expanding or collapsing a reversibly expansible pocket in said electrolyte container or by varying the rate of circulation of said electrolyte solution through said battery cell.

Abstract: An electrolytic cell for the production of aluminum metal comprises a permanent hollow anode structure of substantially corrosion-resistant material, with numerous perforations in the base of said structure, a packed bed of consumable carbon pieces supported by said base within the hollow space of said structure, means for heating said base so as to form a molten cryolite bath upon cell start-up, means for controllably cooling the walls of said anode structure to form a protective layer of frozen cryolite over said walls at the air-cryolite interfaces, means for adding fresh pieces of said consumable carbon to replenish said packed bed when a substantial portion thereof has been consumed, and means for adjusting the depth of immersion of said packed bed within said molten cryolite bath so as to reduce voltage and energy requirements or increase the rate of aluminum production.

Abstract: Apparatus and methods for generating heat and electricity from the consumption of a variety of aluminum products comprise:(a) a reaction chamber containing an aqueous electrolyte solution and adapted for introduction therein of aluminum pieces of various shapes and sizes up to a certain maximum predetermined size and for effecting a chemical reaction between said aqueous electrolyte and said aluminum pieces yielding aluminum hydroxide and an intermediate reactant;(b) means for feeding said aluminum pieces into said reaction chamber in small quantities upon demand;(c) means for removing the heat generated in said chamber as a result of said reaction;(d) means for removing said aluminum hydroxide reaction product; and(e) means for oxidizing said intermediate reactant in an electrochemical cell, thereby generating electrical energy.The intermediate reactant is preferably hydrogen or zinc.

Abstract: Aluminum pieces of various shapes and sizes, up to a certain maximum predetermined size, are introduced upon demand into a reaction chamber wherein they react with an aqueous electrolyte solution to generate heat, electricity, and an aluminum hydroxide reaction product. The aqueous electrolyte solution is usually strongly acidic or strongly alkaline, but the latter is preferred. The electricity may be generated either directly, with said reaction chamber comprising a packed-bed anode forming part of an electrochemical cell, or indirectly, by first generating hydrogen in said chamber, and thereafter consuming the hydrogen in a fuel cell. The heat generated in said chamber is carried away by a circulating fluid and used for space-heating and other applications. The aluminum hydroxide reaction product is removed from the system and recycled in the production of fresh aluminum.

Abstract: Improved oxygen-consuming electrochemical cells are provided with a fluidized-bed oxygen absorber (1), wherein electrolyte-wetted carrier particles (3), especially electronically conductive catalyst particles, are oxygen-enriched, and a substantially bubble-free fluidized-bed cathode (12), wherein the oxygen transported by said carrier particles is electrochemically reduced. Carrier particles comprising activated carbon may provide sufficient surfaces area per unit weight to assure adequate oxygen transport. An intermediary oxidation-reduction couple may be included in the electrolyte to facilitate these oxygen-absorption and electro-reduction steps. The oxygen absorber (1) may be either separated from the cathode (12) or may form part of the same compartment (28), in which case an oxygen-permeable electrolyte-impermeable membrane (23) must be provided through which oxygen from ambient air may readily pass and be rapidly picked up and transported by the fluidized carrier particles (3).

Abstract: Heat and electrical energy are generated from aluminum by introduction of aluminum particles on demand into a reaction chamber for reaction with an aqueous electrolyte solution with the concurrent formation of aluminum hydroxide. Improved packing of the aluminum is achieved by exertion of a positive downward pressure on a packed bed of aluminum by a weighted or spring-loaded piston, the pressure providing improved contact between the aluminum particles with resulting improved electrical continuity.

Abstract: The current-carrying capacity of a fluidized-bed electrode is enhanced by imparting increased velocities to the particles suspended therein while maintaining a relatively low degree of bed expansion or voidage. This is accomplished in one embodiment of the invention by means of pairs of opposing jets of electrolyte impinging against each other so as to effect a highly turbulent motion of the fluidized particles while the net flow velocity of the supporting electrolyte is kept relatively low. In a second preferred embodiment, the electrolyte flow velocity may be as high as desired, but its direction, preferably horizontal, is reversed at frequent intervals. The suspended particles get thereby intermittently packed against and retained by filters at the alternating outlet walls. The alternating packing and expansion result in improved charge and mass transport, and hence in improved electrode performance.

Abstract: Aluminum pieces of various shapes and sizes, up to a certain maximum predetermined size, are introduced upon demand into a reaction chamber wherein they react with an aqueous electrolyte solution to generate heat, electricity, and an aluminum hydroxide reaction product. The aqueous electrolyte solution is usually strongly acidic or strongly alkaline, but the latter is preferred. The electricity may be generated either directly, with said reaction chamber comprising a packed-bed anode forming part of an electrochemical cell, or indirectly, by first generating hydrogen in said chamber, and thereafter consuming the hydrogen in a fuel cell. The heat generated in said chamber is carried away by a circulating fluid and used for space-heating and other applications. The aluminum hydroxide reaction product is removed from the system and recycled in the production of fresh aluminum.

Abstract: This invention deals with methods and apparatus for producing unsupported monocrystalline films of silicon, germanium, gallium aresenide, and many other semiconductors and other materials. Said methods comprise:(a) repetitively using a monocrystalline substrate S having a crystal structure closely matching that of the desired films;(b) epitaxially depositing on substrate S first an intermediate monocrystalline layer I and next an outer monocrystalline layer 0 so as to form a three-layer S-I-O configuration, said three layers having closely matching crystal structures; and(c) at least partly disintegrating said intermediate layer I so as to free said outer layer 0 and make substrate S available to repeat the same cycle.

Abstract: An electrochemical power generation apparatus and methods of control thereof are described. The power source comprises one or more electrochemical cells having an anode and an oxygen or hydrogen peroxide depolarized cathode, a liquid electrolyte solution, electrolyte circulation means and an electrolyte container. The methods include varying the volumes of electrolyte in said container and in said battery cell so as to control the polarization and hence the cell output voltage of said anode and cathode. The anode is of the consumable-metal type, particularly aluminum. The method of varying the volume may be effected by expanding or collapsing a reversibly expansible pocket in said electrolyte container or by varying the rate of circulation of said electrolyte solution through said battery cell.