Abstract: A system for describing a target organism is disclosed (1) that includes a flow cytometer that receives a liquid analyte sample; and (2) a processor. The cytometer includes a laser, a flow cell for passing the analyte past a beam of light emitted from the laser, a first photodetector for detecting the peak intensity of light emitted from the analyte at a predetermined wavelength and then generating a signal, a second photodetector for detecting the duration of emitting light and generating a second signal, the second signal reflecting the size of material in the analyte. The processor compares data from the first and second signals, where the comparison defines a region R1 having a minimum and maximum value for the first signal and minimum and maximum value for the second signal, and sets a threshold level of counts in the region R1 using data from a first background measurement. The processor then compares a second measurement to the threshold value to determine if the threshold value is exceeded.

Abstract: A chemical sensor comprising a gas detector having first and second printed wiring boards with opposed separated pairs of signal and grounded counter electrodes and processing electronics for processing ionic current signals derived from the signal and counter electrodes. A corona discharge source is provided that produces an ionized air stream containing a chemical that is to be detected. An insulating plate is disposed between the second printed wiring board of the gas detector and the corona discharge source that is used to electrically isolate the electrodes and processing electronics of the gas detector from the corona discharge source. An air flow passage is formed through the corona discharge source, the insulating plate, and the gas detector that allows the ionized air stream generated by the corona discharge source to flow past the signal and counter electrodes, so that the chemical may be detected.

Abstract: The composition of an electrically conductive mixture, such as a mixture of gasoline and alcohol, is measured using a single measurement cell having a first electrode and a second electrode with a measurement space therebetween for receiving a specimen of the mixture. With a specimen of the mixture in the measurement space, the first electrode is alternatively connected to a reference discharge voltage, preferably ground, and to an applied voltage through a resistor. A first operational state encompasses the period when the first electrode is connected to the reference discharge voltage and a second operational state encompasses the period when the first electrode is connected to the applied voltage through the resistor. A first operational state peak voltage is measured during the first operational state, and a second operational state peak voltage is measured during the second operational state.

Abstract: An improved ion mobility spectrometer for detecting chemical warfare agents and hazardous vapors. The ion mobility spectrometer has an improved sensor cell that includes a heated air flow assembly, an ionization assembly and a field electrode and detector assembly printed circuit assembly. The heated air flow assembly includes a cover with an air inlet, an ambient temperature sensor, a thin-film heater element, a heater frame, a heated air sensor, and a heater channel formed therein. The ionization assembly comprises a nuclear ionization source attached to a holder, a lid, and an ionization channel formed therein that is coupled to the heater channel. The field electrode and detector assembly printed circuit assembly comprises a field electrode printed circuit board, a detector electrode printed circuit board, and detector electronics. The field electrode printed circuit board has a plurality of field electrodes disposed on a bottom surface thereof.

Abstract: A sensor system and method are provided that are capable of the real-time detection of target live microorganisms, such as biological warfare agents. The sensor system includes a highly-sensitive, highly-selective sensor cell that comprises a single-stranded oligonucleic acid sequence that is complementary to a portion of the DNA of a target live microorganism, the oligonucleic acid having been modified with the covalent attachment of electron donor and acceptor moieties. In the presence of the targeted microorganism, hybridization occurs between the modified oligonucleic acid and the microorganism's DNA, such that the electron conductance between the electron transfer moieties greatly increases, thereby providing a means of detecting the presence of the target live microorganism.

Abstract: The composition of an electrically conductive mixture, preferably a mixture of gasoline and alcohol, is measured using a single measurement cell having a first electrode and a second electrode with a measurement space therebetween for receiving a specimen of the mixture. With a specimen of the mixture in the measurement space, the first electrode is alternatively connected to a reference discharge voltage, preferably ground, and to a feedback control voltage. A first operational state encompasses the period when the first electrode is connected to the reference discharge voltage and a second operational state encompasses the period when the first electrode is connected to the feedback control voltage. A first operational state peak voltage is measured during the first operational state, and a peak second operational state voltage is measured during the second operational state.

Abstract: An improved device for monitoring the presence of toxic metals in workplace air comprises a base and a removable top assembly. The top assembly includes a test substrate, such as filter paper, having a first surface and a second surface. The first surface is supported by the top assembly and the second surface has an area that is sensitized with at least one chemical reagent for producing a reaction with at least one toxic metal. The base has an air inlet, an air outlet, and a channel connecting the air inlet and the air outlet, thereby enabling air entering the monitor from the air inlet to directly contact the area of the second surface of the test substrate prior to exiting the monitor through the air outlet.

Abstract: An device for monitoring workplace air comprises a monitor cell comprising a base and a removable assembly. The removable assembly comprises (1) a flat, electrically insulating substrate having a first surface, (2) an electrolyte cell having an anode and a cathode disposed on the first surface, the anode and cathode spaced apart to define a controlled volume for holding a quantity of an electrolyte, and (3) means for applying a controlled electrical potential to the cathode. The base comprises (1) an air inlet portion for sampling air, (2) an air outlet portion connected to an air sampling pump, (3) a channel connecting the air inlet and the air outlet and adapted to introduce air to the electrolyte in the electrolyte cell, (4) a reservoir for storing the electrolyte for the electrolyte cell, and (5) a wick for supplying electrolyte from the reservoir to the electrolyte cell.

Abstract: The surface of a fatigue-resistant eutectic or near-eutectic lead/tin solder containing at least one doping element of cadmium, indium, and antimony is treated with an aqueous solution of an acidic chloride or acidic nitrate. The surface treatment method of the present invention removes, or substantially reduces, the presence of any cadmium, indium, and/or antimony, as well as the oxides of tin and lead, leaving a surface that is substantially tin and lead. The resulting treatment renders the solder compatible with mildly reducing fluxes of low activity and improves the wettability of the solder.

Abstract: A glass composition having a composition between about 18 and about 23 mole % Na.sub.2 O, about 3 to about 7 mole % Cs.sub.2 O, the balance being B.sub.2 O.sub.3 is adaptable to match the thermal expansion coefficient of a beta"-Al.sub.2 O.sub.3 solid electrolyte when used to bond and seal the solid electrolyte to a porous support plate (22) in a sodium-sulfur battery (10).

Abstract: The present invention is a method for improving the quality of glass to graphite bonds and seals used in high power density batteries, such as sodium-sulfur batteries. The method comprises depositing an interlayer of a two-element compound formed from a group IVa or Va metallic element and a group Vb or VIb nonmetallic element, preferably titanium nitride, between the glass and graphite. The resultant structure is mechanically strong, and forms a leak-free bond when used in such batteries. The invention further comprises batteries including seals formed by the disclosed method.

Abstract: A sensor and system for monitoring the accumulation of contaminants in oil wherein the contaminants have an electrical conductivity which is different from the oil. An electrochemical cell is used to measure the alternating current conductivity of the oil to provide an indication of the amount of contaminants present in the oil. Acids and water are two common engine oil contaminants which are accurately monitored by this alternating current conductivity measurement system.

Abstract: A system and process for metering the delivery of liquids wherein the conductivity of the liquids is monitored at a metering device, such as a spray gun. Measurement of conductivity at the metering device provides continual measurement for fluctuations in conductivity and is useful for controlling liquid flow during sequential metering of different liquids.

Abstract: Method of reducing the amount of acetylene impurity present in hydrogen chloride gas comprising contacting said gas with an oxidation catalyst in the presence of an oxygen-containing gas to form carbon monoxide and/or carbon dioxide and water. The method of the present invention is particularly adapted to remove acetylene impurities from hydrogen chloride streams used in the oxychlorination of ethylene in the presence of a catalyst.