Abstract: A cold crucible for melting and crystallizing non-metallic inorganic compounds having a cooled crucible wall in the form of metal pipes through which cooling medium flows which are in mechanical connection with the bottom of the crucible through which cooling medium also flows, and having an induction coil which surrounds the wall of the crucible and via which high frequency energy can be coupled in the contents of the crucible and having a second induction coil which can be controlled independently of the induction coil surrounding the wall of the crucible and which is provided below the bottom of the crucible, and having a crucible bottom consisting of a dielectric material.

Abstract: An apparatus has a crucible for containing a GaAs raw material melt and a B.sub.2 O.sub.3 liquid encapsulating material therein, a heat generator arranged around the crucible so as to be coaxial therewith, and a heat insulator assembly arranged around the heat generator to surround the heat generator and the crucible for the purpose of manufacturing a compound semiconductor single crystal by pulling it from the raw material melt in the crucible by the LEC method. In the heat insulator assembly of the apparatus of the above construction, an upper heat insulator, arranged above the crucible and having at its center a circular hole for receiving the single crystal being pulled, comprises a plurality of radially divided sector-shaped split members. The split members are sintered bodies having aluminum nitride (AlN) as a major constituent.

Abstract: An apparatus and method are provided for the precisely controlled and coordinated, concomitant supply at optimal flow rates, by differential pumping, of selected sample and sheath liquids from respective pluralities of different sources thereof, to the same sheath stream flow cell for successive different types of sample analyses, thereby maximizing sample analysis accuracy and reproducibility, and reducing apparatus complexity and costs. The apparatus and method are particularly useful in high-speed automated biomedical analytical systems.

Abstract: A machine for transferring liquids to and from the wells of assay trays in a controlled, automated manner and a solid phase assay tray for use with the machine. The machine includes a horizontally translatable table (15) that holds the tray (46), a plurality of liquid dispensing manifolds (54) for dispensing liquids into the tray wells (50) and an aspirating manifold (65) for aspirating liquid from the well. The dispensing and aspirating manifolds are mounted on a vertically translatable head (16) above the table. Each dispensing manifold is equipped with a row of dispensing tubes (56) and is connected via a pump (58) to a liquid container (62). The aspirating manifold is equipped with a row of aspirating tube (66) and is connected via a pump (69) to a waste liquid receptacle (73). A microprocessor (85) controls the movements of the table and manifolds and operates the pumps.

Abstract: Thin films of hygroscopic, halogenated organic polymer having pendant groups of a relatively strong acidic type (e.g., sulfonic groups) and pendant groups of a relatively weak acidic type (e.g., carboxylic groups) are employed for humidity sensing by electronic, acoustic, and optical techniques.

Abstract: A process for in situ simulation of diagenetic processes in a subterranean formation is provided. A mineral substrate is placed in the formation of interest in a sealed vessel. The vessel is opened so as to expose the mineral substrate to formation fluids. After sufficient time for the formation fluids to act upon the mineral substrate, the substrate is removed from the formation and is examined for physical and chemical effects indicative of porosity changes in the formation.

Abstract: A dosimeter is provided for collecting and detecting vapors and aerosols of organic compounds. The dosimeter comprises a lightweight, passive device that can be conveniently worn by a person as a badge or placed at a stationary location. The dosimeter includes a sample collector comprising a porous web treated with a chemical for inducing molecular displacement and enhancing phosphorescence. Compounds are collected onto the web by molecular diffusion. The web also serves as the sample medium for detecting the compounds by a room temperature phosphorescence technique.

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: Reactive gases like, for example reducing gases, specifically carbon monoxide, are detected in a gas mixture, particularly in air, with extremely high sensitivity and with high precision using a gas detector in which the attenuation of the intensity of an infrared radiation beam by a catalyst layer is utilized. Such catalyst layer contains at least one transition metal selected from at least one of the groups I, VII, and VIII of the Periodic Table of the Chemical Elements. Preferably, chemical elements are used having an atomic weight in the range of about 100 to about 205. The detection of carbon monoxide is particularly sensitive using a catalyst layer which substantially contains a metal capable of forming a carboncarbonyl compound with carbon monoxide.

Abstract: A gas sensor including a gas sensor body in which is centrally inserted a gas detecting element and which permits the gas sensor itself to be attached to other members; a protective sleeve attached to an end portion of the gas sensor body; a seal member formed of a heat-resistant synthetic resin, the seal member being disposed inside an end portion on a lead wire draw-out side of the protective sleeve, with a lead wire extending through the seal member; and a spring member mounted within the protective sleeve for urging the seal member liquid-tightly against the lead wire draw-out side end portion of the protective sleeve. Since the seal member disposed in an end portion of the protective sleeve is formed of a heat-resistant synthetic resin, the durability thereof is improved even where high temperature gases such as the exhaust gases of internal combustion engines or the like are to be detected.

Abstract: Apparatus and methods for measurement of total organic carbon content of water, particularly of low relative organic content, are described which feature a single sample cell for exposure of a static sample to ultraviolet radiation comprising electrodes for measuring the conductivity of the water. The conductivity is monitored as a function of time and the second time derivative of the conductivity signal is monitored to indicate when the oxidation reaction has been completed. Compensation for the contribution to conductivity of the water sample made by the instrument is achieved by subtracting a quantity proportional to the first time derivative of the conductivity at a time when the second time derivative reaches zero, indicating that the oxidation reaction is complete, from the change in the total conductivity measurement, the remainder being equal to the contribution to conductivity made by oxidation of the organic content of the water.

Abstract: A trimode gas detection instrument having three operating modes, one which monitors the level of combustible gases, a second which monitors oxygen, and a third which monitors the displacement of air by an unknown gas. Only two sensors are used, a combustible gas sensor and an oxygen sensor. A switch selects the input to a readout so that the user can quickly observe the concentration readings in any of the three modes. In the depletion mode the readout is calibrated in relation to the inverse of the normal concentration of oxygen in air--i.e., zero depletion corresponds to an oxygen concentration of 21%. In the event that an unknown gas displaces air in a sample atmosphere, concentration of the unknown gas appears on the readout, such that zero oxygen corresponds to a concentration of 100% unknown gas.

Abstract: Two or more crucibles containing different source materials to be vaporized are arranged concentrically, with their mouths open to a vapor chamber defined by an open top envelope within a vacuum housing. The vacuum housing is evacuated while the vapor chamber is held open. Then, with the vapor chamber closed, heat is applied to the crucibles as well as to the envelope to evaporate the source compounds within the crucibles. A substrate is held against the open top of the vapor chamber when the vapor pressure therein rises to a predetermined degree, thereby causing deposition of the vaporized source materials onto the substrate in the form of a crystalline compound film. As required, an impurity evaporator may also be provided within the vacuum housing for doping the compound film. The substrate having the crystalline compound film grown thereon may be moved from over the vapor chamber to a position over the impurity evaporator.

Abstract: Temperature programmed spectroscopy wherein particles of a substrate under investigation are attached in a non-overlapping manner to a heating filament. The temperature of the filament is increased in a controlled manner, thus increasing the temperature of the attached substrate particles as well. An instrument for analyzing the gases is a mass spectrometer. Gases desorbed from the particles can be studied according to this technique, or the nature of heterogeneous catalytic chemical reactions of a gaseous atmosphere on the particles' surface may alternatively be detected and studied.

Abstract: A gas sensor comprising a device by which photo absorption is changed in the presence of hydrogen gas or hydrogen containing compound gas and an optical detecting means for detecting the change of photo absorption. The device is provided in the form of a laminate made of a metal adsorbing and dissociating hydrogen or hydrogen containing compound gas and a solid compound which is reduced by hydrogen atoms produced in the metal to change photo absorption.

Abstract: Apparatus for replenishing a melt while a crystal growing operation is in process. The apparatus comprises an elongated hollow housing member having an open top end and a closed bottom end. A vertically movable support means for supporting a charge of source material, to be added to the melt, is located within the hollow housing member. The apparatus further comprises a conduit means for delivering a predetermined charge of source material to the support means. A charge of source material is delivered to the melt by operation of a retractor means that retracts the support means downwardly within the hollow housing member against the force of a spring means that yieldingly biases the support means upwardly within the hollow housing member towards the open top end of the hollow housing member. When the support means reaches a predetermined release point in its downward motion, the retractor means automatically releases the support means to the force of the spring means.

Abstract: The invention relates to a reaction support incorporating multiple recipients for testing liquid doses, comprising a transparent plate provided with a plurality of recesses of which each forms one of the recipient. According to the invention, this support is characterized in that the plate is in the form of a disc and in that the recesses are obturated at the top and are each in communication with the outside via an eccentric orifice opening on the upper face of the disc. The invention is particularly applicable in the domain of biology.

Abstract: Apparatus for continuously forming a silicon crystal sheet from a silicon rod in a noncrucible environment. The rod is rotated and fed toward an RF coil in an inert atmosphere so that the upper end of the rod becomes molten and the silicon sheet crystal is pulled therefrom substantially horizontally in a continuous strip. A shorting ring may be provided around the rod to limit the heating to the upper end only. Argon gas can be used to create the inert atmosphere within a suitable closed chamber. By use of this apparatus and method, a substantially defect-free silicon crystal sheet is formed that can be used for microcircuitry chips or solar cells.

Abstract: A battery-operated portable breath tester is disclosed. The breath tester includes a housing which defines a sleeve for receiving a wand. The wand defines an internal sample chamber, with a lamp at one end for providing infrared energy and a detector at an opposite end for receiving the infrared energy after it has passed through the sample to be tested. The wand defines opening extending from the internal sample chamber to the outside of the wand. The wand has an external shape providing a snug fit within the sleeve. As the wand is moved within the sleeve, gas is purged from the wand. The wand is connected to the housing by means of an electrical coil. The housing encloses a digital voltmeter including a digital display for providing a test readout. The digital voltmeter includes an oscillator which is coupled through a frequency divider and a transistor switch to the lamp.

Abstract: Processes for testing immobilized biological material with generally biochemical and histochemical methods, particularly enzyme, immuno and hormone chemical methods can be improved by adhering the biological material to the surface of a support and then fixing the support to a plate. The plate is constructed in such a way that the biological material is protected from damage. Using a biological testing technique such as thin section immunofluorescence testing the invention makes it possible to carry out biochemical tests in a more rational and trouble-free manner than with hitherto known methods. If necessary, a random number of tests can be performed side-by-side on a single plate. The invention makes it possible to simply and rapidly prepare frozen section products and store them in a space-saving manner at very low temperatures. The adhesion of the frozen sections to the support can be improved by coupling chemicals which react with the tissue by bonding thereto to the support.