Abstract: Porous agglomerates are made from pure tungsten by sintering fine particles together and mechanically breaking down the mass to form some agglomerates considerably larger than the particles. These agglomerates are mixed with fine iridium powder and sintered to form a porous mass. The mass is machined to the cathode shapes and impregnated with an alkaline earth aluminate. The large agglomerates alloy with the iridium only on their outer surface. Their pure tungsten interior provides the surfaces to reduce the alkaline earth oxide to the metal which activates the cathode.

Abstract: A circular magnetron sputter source employs a central anode surrounded by an annular cathode of generally inverted conical configuration. The anode structure forms a composite anode and inner magnetic pole piece which is operated at or near ground potential. An outer magnetic pole piece concentrically surrounds the annular cathode. This outer pole piece is electrically isolated from the cathode, and held at or near ground potential. The cathode is operated at a potential of several hundred volts negative with respect to ground. The cathode is held in place by a novel retainer means and has a novel cross section configuration. Magnetic flux is provided either by permanent magnets or by electromagnets or by a combination of both located externally of the vacuum chamber in which the sputter source is operated. Magnetic field lines pass from the outer pole piece and through the cathode, exiting the sputter surface near the outer edge of the cathode.

Abstract: A sample valve for solute modulated synchronous detection alternately directs into a detector a sample gas stream F.sub.1 which passes through a modulator cell and a reference gas stream F.sub.2 which passes through a balance cell. The sample valve is made of a symmetrically structured chamber with inlets and outlets. An ordinary valve causes a control gas to stream into the chamber alternately though one of two openings to exit openings of the chamber are synchronously opened and closed so that gas streams F.sub.1 and F.sub.2 are alternately led into the detector and out of the system.

Abstract: A microprocessor based electronic teaching aid which enables a student viewing a display containing text material being studied to designate any word or portion of text for definition or for vocalization by synthesized speech techniques wherein the reading material being studied is supplied in the form of a programmed Source ROM which contains pointers to the start addresses for the words of the reading material with reference to an internally provided dictionary. A program causes the creation of the text display responsive to the Source ROM data, and includes techniques for being able to define and vocalize any selected word. This combination of hardware and software permits a significant reduction in the cost of this teaching aid by elimination of disk drives or tape drives.

Abstract: In a high-performance, high-pressure liquid chromatography system, gradient elution of solvent components from a plurality of component reservoirs can be accomplished according to a programmed temporally variable ratio by a single reciprocating pump. The pumping cycle comprises a plurality of fill strokes with intervening pumping strokes. During one of the fill strokes of the cycle, a proportioned mixture of solvent components is admitted to the pump chamber from the respective reservoirs by means of proportioning valves. During each of the other fill strokes of the cycle, only a single solvent component is admitted to the pump chamber. Consequently, a relatively low concentration of a particular component can be delivered by the pump with precision over a complete pumping cycle, although a comparatively higher and therefore more accurately measurable concentration of that component is admitted to the pump chamber during any given fill stroke.

Abstract: Apparatus and method for injection of samples directly onto a column in a gas chromatograph with injection occurring in a temperature controlled zone outside the oven. The apparatus combines a guide means and valve assembly in alignment with an injection and thermal transfer assembly. In the guide means and valve assembly a radial seal engages the injection means to seal the injection volume, thereby eliminating back flash. In the injection and thermal transfer assembly the capillary column is centered and held in fixed position within a duct means. Means is provided to lower the temperature of the capillary column to a temperature below the vaporization temperature of the liquid sample prior to injection. After injection, means is further provided to raise the temperature of the capillary column to a temperature above the volatilization temperature of the liquid sample to vaporize it and pass it into the capillary column.

Abstract: A syringe drive system having a structure for supporting the body of a syringe in a particular disposition and retaining the syringe body against axial movement. A drive motor is secured to the structure so as to have a drive shaft thereof in alignment with the syringe body. The drive shaft is arranged to move axially in response to energization of the motor and is connected to the plunger stem of the syringe through a coupling which is slideably mounted on the support structure. The arrangement is such that energization of the motor causes movement of the coupling block in the axial direction of the syringe and the syringe plunger is depressed or withdrawn accordingly.

Abstract: An electronic teaching aid which enables a student viewing a visual display containing text material being read or studied to designate any words or portion of said text for immediate audible vocalization or alternatively to designate any word of said test for immediate visual display of the definition of said designated word.

Abstract: A method and apparatus for carrying out atomic spectroscopy, and particularly atomic absorption and atomic fluorescence spectroscopy. The method involves passing the emission spectrum of a light source through an atomized sample, changing the relationship between a selected emission line of the emission spectrum and a corresponding absorption line of the atoms of interest and measuring the absorption of that emission line by the sample before and after the aforementioned change in relationship. The change in emission and absorption line relationship can be effected by application of the Zeeman Effect, Stark Effect, or Doppler Effect. The apparatus, in one form, includes an electro-magnet operative to apply a magnetic field to the atomized sample and thereby cause splitting and shifting of the aforementioned absorption line, and the magnet is modulated to effect periodic variation of the spectral line relationship.

Abstract: Method of operation and apparatus for a salt gradient solar pond employing a novel barge carrying a plurality of two axis stabilized high temperature concentrator solar cell arrays including means to control the flow rate of the concentrator solar cell array cooling fluid to optimize power station characteristics.

Abstract: A method of controlling spectroscopic analysis in which a sample in liquid concentrate form and containing an element of interest, is nebulized and carried into an analysis zone by pressurized support gas. The invention comprises regulating the flow rate of the support gas to control the density of atoms of the element present in the analysis zone so as to be within a measurable range. The flow of support gas controls sample uptake at the nebulizer, and that uptake is reduced by dividing the gas flow before the nebulizer so that one part by-passes the nebulizer but is nevertheless directed into the analysis zone so that the total gas flow to the analysis zone remains constant.

Abstract: Accurate non-invasive temperature control of NMR samples without reduction of spectral quality is provided by placement of multiple sensors in the probe structure, the output of said sensors being weighted to provide an averaged reading of sample temperature in the receiver coil region.

Abstract: The present inventive fluorometer provides a rapid means for accurate sample quantitative measurements by making instrumental calibration measurements during sample equilibration time. Increased speed of equilibration and calibration and simultaneously performing these two functions increases the throughput speed with which individual measurements can be accomplished, thus increasing the number of samples which can be routinely processed. This decreases the cost per test and more importantly renders new treatment protocols possible which require the doctor and patient to be able to know within minutes the level of certain drugs in various body fluids.

Abstract: Apparatus and method for reduction of noise in NMR signals during high power heteronuclear decoupling experiments. A material is introduced into the evacuated area of the variable temperature probe to decrease collisional probability of ions generated in the interwall space of the evacuated envelop.

Abstract: A pulse damper for use in high-pressure liquid pumping applications, such as liquid chromatography, comprises a stainless steel cylindrical housing structure having threaded end caps to which inlet and outlet fittings are attached for coupling to a high-pressure liquid flow line. A spool made of a plastic material such as polytetrafluoroethylene or a perfluoroelastomer is fitted tightly within the housing structure, so that flow line liquid passes through the damper via the axial bore of the spool. The outer portion of the spool is configured to provide a cavity between the spool and the surrounding housing structure, and a compressible liquid fills this cavity. In operation, when a pressure pulse occurs in the flow line liquid, the relatively thin cylindrical wall of the spool expands radially outward in response, thereby causing a compression of the liquid in the surrounding cavity.

Abstract: Oscillations due to backward waves in a high-power traveling-wave tube (TWT) are inhibited by a non-reciprocal attenuating device which essentially absorbs only backward waves. A directional coupler mediates the exchange of energy between the TWT interaction circuit and an external circuit containing a non-reciprocal loss element such as a ferrite isolator. In such embodiments the high-frequency power handled by the isolator is much less than the power in the TWT interaction circuit. The frequency band handled by the isolator is much narrower than that handled by the TWT. Coupling to the loss element is through one or more resonant circuit elements such that a "notch" of attenuation is obtained for a backward wave only, at a certain frequency where oscillations are prone, such as the frequency associated with 2.pi. phase shift per cavity in a coalesced-mode coupled-cavity TWT.

Abstract: In a gas chromatography system of the type including an oven for the GC column, and an electric heater for controllably heating the oven; an improved system is disclosed for controllably opening and closing the oven door to enable a fully controlled heat leak, thereby to stabilize the oven temperature at a desired set point. A signal indicative by first or second conditions of an oven temperature above or below the set point is generated. A heater power control responds to one of the signal conditions by effecting heating of the oven. Bi-directional door motor and actuator means are provided for opening and closing the oven door over a prescribed operating range, and these means are enabled to operate for a predetermined period upon the signal in its first or second condition departing from preset threshold values for a predetermined period whereby closing or opening of the oven door is effected in incremental steps.

Abstract: Dimensionally optimized flame ionization detector for use in chromatography in which positive ions are caused to be collected by applying positive potential to flame tip. It has been discovered that there exists optimum dimensions of the collector electrode and the spacing between collector electrode and flame tip to resist glassing and corrosion without diminishing other operating parameters. The collector electrode inside diameter is in the range of 0.114 inch to 0.3 inch and the flame tip to collector electrode is in range from 1 mm to 3 mm.

Abstract: In a liquid chromatography system, the effluent from the chromatographic column is passed through a detector flow cell, which is packed with a stationary phase that is adsorptive of the sample species to be detected. Detection of the sample species adsorbed at the stationary phase is effected by measuring fluorescence emitted from such species in response to electromagnetic radiation incident thereon at the flow cell. The fluorescing species, which are in equilibrium between the stationary phase and the mobile phase in the flow cell when fluorescence is being measured, can be detected at lower concentration thresholds than when the fluorescing species are in equilibrium only with the mobile phase.

Abstract: A method and apparatus for carrying out atomic spectroscopy, and particularly atomic absorption and atomic fluorescence spectroscopy. The method involves passing the emission spectrum of a light source through an atomized sample, changing the relationship between a selected emission line of the emission spectrum and a corresponding absorption line of the atoms of interest and measuring the absorption of that emission line by the sample before and after the aforementioned change in relationship. The change in emission and absorption line relationship can be effected by application of the Zeeman Effect, Stark Effect, or Doppler Effect. The apparatus, in one form, includes an electro-magnet operative to apply a magnetic field to the atomized sample and thereby cause splitting and shifting of the aforementioned absorption line, and the magnet is modulated to effect periodic variation of the spectral line relationship.