Abstract: An apparatus for photometrically analyzing liquid samples comprises a capsule (1) in which a measuring cell (7) is housed. This cell is inserted in a flow circuit for liquid samples delivered from containers (R) travelling on a conveyor (17). Each sample is taken up by a pivoting arm (15) and with the aid of a pump (13). The volume of the measuring cell (7) is so calculated that the quantity of liquid sample contained in the containers (R) is sufficient firstly to rinse the cell with this liquid then for the measurement to be carried out. A particular application is the measurement of bioluminescence reactions produced in samples containing living organisms.

Abstract: Method and apparatus for analyzing fluid inclusions. A sectioned mineral sample is mounted on a glass slide and placed in a vacuum chamber. An optical microscope is used to examine the sample through a window in the vacuum chamber to identify a single fluid inclusion. A linear rotary feedthrough includes a diamond stylus on the end thereof that is received in the vacuum chamber. The feedthrough is manipulated by the operator to urge the diamond stylus against the identified fluid inclusion thereby rupturing the same. The gases, including evaporated volatile liquids, released from the inclusion are analyzed by a mass spectrometer.

Abstract: In the method for measuring cell counts or methane producing activity of Methanogens according the present invention, an extracted liquid is prepared by adding an addition solution for extracting a particular fluorescent substance inherent to Methanogens, for example, F.sub.420 exciting in the energy metabolism system of Methanogens in the object for examination and functioning as the electron carrier in the electron transport system or by heating the first object for examination. Since a particular fluorescent substance existing in the Methanogen cells in the first object for examination has been extracted out of the Methanogen cells, the intensity of fluorescence is increased upon measurement thereof.

Abstract: In accordance with the present invention a microdevice 10 is set forth for gas sensing. The microdevice 10 includes a conductive substrate 12 having an insulator layer 14 on a surface 16 thereof, the insulator layer 14 having an opening 18 therethrough exposing a portion 20 of the surface 16. A conducting member 22 is in contact with the insulator layer 14. The member 22, the insulator layer 14 and the portion 20 of the surface 16 define an ionization chamber 28. Gas can flow through the ionization chamber 28. A potential difference is applied between the substrate 12 and the member 22. The current flowing between the substrate 12 and the member 22 is measured. A microdevice 10 as disclosed herein uses very little power and has very high sensitivity.

Abstract: A bioreactor and method of its operation are described comprising a vertical column with a lower reaction section filled with column packing particles classifiable by means of their differential settling rates in a liquid, and an upper disengagement section, preferably of larger diameter and of equal or greater volume than the reaction section, the two sections desirably being connected by a transition section in the shape of an inverted, truncated cone. Following initial classification of the packing in the reaction section, the packing is inoculated with microorganisms, and the bioreaction commenced by introducing nutrient feed at one end of the column, and withdrawing product at the other end. The packing is periodically cleaned, as required, by dispersing it into the disengagement section by passing liquid at an increased velocity upward through the column until contaminants have been dislodged.

Abstract: A method of freezing, storing and thawing collagen-rich tissue, such as heart valves. The method includes a freezing profile for freezing the tissue down to the temperature of liquid nitrogen with minimal tissue damage due to ice crystal formation. Heart valves cryopreserved according to the present process exhibit a high cell viability when thawed and are suitable for implanting in human patients.

Abstract: A mass transfer apparatus and method is based upon use of a mass transfer chamber, such as a hollow fiber membrane bioreactor, with means to change the directional flow therethrough for enhancement of the mass transfer operation. The invention has particular utility in cell growth systems, where the periodic reversal of flow direction of a nutrient stream passed through the bioreactor equalizes dispersion of cell growth through the bioreactor and enhances the transport of metabolic waste from the cells being grown.

Abstract: Isoenzyme control reagents and methods for making same stabilized by means of plexiform stabilizing means. The preferred plexiform stabilizing means is selected from the group consisting of monosaccharide and disaccharide reducing sugars. The most preferred isoenzyme control reagent comprises the isoenzyme of interest obtained from selected tissue, preclarified human sera, stabilizing cofactor, a chelating agent means, a weak nonphospate buffer and lactose as the most preferred plexiform stabilizing means.

Abstract: The present invention relates to a process for indicating toxic substances in air that is supplied to accommodation used for personnel, preferably the cab of a motor vehicle, this having error compensation for humidity and temperature in one or a plurality of semiconductor gas sensors that are used, in which connection the sensor heating voltage is controlled to provide constant heating output and the sensor temperature pick up as well as the necessary amplifier (control stage) used to generate the temperature-varied heating voltage are arranged in a common housing, and that in the area of the sensors this housing is perforated.

Abstract: A method for the qualitative assessment of oxidative drug metabolism deficiencies, preferably for the qualitative assessment of dextromethorphan metabolism, in a subject comprises analyzing a sample fluid from the subject, for example urine, which contains metabolites of a probe drug using high performance thin layer chromatography.

Abstract: A fluorescent analyzer including a light source which irradiates a sample with direct light, a first wave selector for passing a predetermined wavelength of light emitted from the light source, a sample cell for holding the sample which is irradiated by light passed by the first wave selector, a second wave selector arranged sidewards of the sample outside a direct path of light from the light source passing straight through the sample for passing light of a second predetermined wavelength emitted from the sample upon irradiation by direct light from the light source, a first light detector for producing a first output signal indicative of the amount of light of the second predetermined wavelength passed by the second wave selector, a second light detector for producing a second output signal indicative of the amount of direct light of the first predetermined wavelength passing straight through the sample, a correction circuit for performing a predetermined correction on the amplitude of the first output sign

Abstract: An assay kit comprising an analyte test strip and a color comparator including a plurality of different color fields arranged in an ordered, preferably linear, succession. There is an aperture through each color field so positioned that the reaction zone of the test strip can be placed behind each color field and the color of the reaction zone thereafter viewed through each aperture, with the particular color field framing at least a portion of the reaction zone. The color comparator can be in the form of overlapping panels of a folder or a label on a bottle. There may be a chart of numerical assay values of the color fields such that the edge of the testing strip underlies the numerical value of the color field being viewed, or the testing strip may have a window therein which frames the numerical value of the color field being viewed. This invention has application in test kits for biological substances, (i.e. glucose, cholesterol) and drugs of abuse; and, in test kits for environmental toxins.

Abstract: Methods and apparatus for monitoring the reaction between a metal, and/or metal oxide, reactive with nitrous oxide wherein a mixture of nitrous oxide and a diluent is passed through a bed of a material containing the metal, or metal oxide, and the time to a marked change in the exit gas composition is determined. The procedure is of particular utility for metal surface area determination.

Abstract: A dye development composition comprising 1,10-phenanthroline and 1,7-dihydroxynaphthalene is disclosed for use in assaying high levels of hydrogen peroxide.

Abstract: Low viscosity heteropolysaccharides, e.g., xanthan gum, S-194, and guar gum, are disclosed. These gums are especially useful in preparing herbicidal compositions.

Abstract: Low viscosity heteropolysaccharides, e.g., zanthan gum, S-194, and guar gum, are disclosed. These gums are especially useful in preparing herbicidal compositions.

Abstract: An apparatus for collecting and preserving fluid biological evidence comprising a specimen vial and lid, the lid having an adhesive coated disk inserted therein with the lid initially being inverted on the rim of the specimen vial and encased in a tamper evident plastic wrapper. The specimen vial and lid, encased in the tamper evident wrapper, are sealed along with a pair of adhesive backed sealing tapes, an instruction manual, and a compressible foam cushioning pad, within an outer container with a second tamper evident plastic wrapper.

Abstract: A chemical test kit and method for detecting the presence of impurities in an oil sample is provided. The test kit is comprised of two flexible translucent or transparent containers, each with at least one breakable capsule mounted within it. One of the flexible containers has a means for separating an aqueous layer from an oil layer. The capsules contain reagents capable of extracting the impurity to be detected from the oil into an aqueous layer and indicating the presence of a threshold concentration of the impurity. The method involves the steps of introducing an oil sample into a first flexible container, breaking the capsule within it by squeezing the flexible container in the vicinity of the capsule, transferring the aqueous layer to the second container, and breaking the capsule within the second container in the same manner. A chemical reaction occurs in the second container indicating whether the impurity is present at a given threshold concentration.

Abstract: An aqueous solution containing 0.00005 to 0.2 mol/l of copper ion and 0.0001 to 1.0 mol/l of nitrate ion is effective to detect phosphorus segregates in a metallic material, particularly cast steel. Segregated phosphorus can be detected by etching a surface of steel to be tested, attaching test paper onto the steel surface, applying the aqueous solution to the paper, maintaining the paper in contact with the steel surface until stains appear, and removing the paper from the steel surface. A red print is obtained when the solution is pH 6 or higher. A blue print is obtained by following the above steps, and further treating the paper with a color reagent containing molybdate ion, and then with a reducing agent.

Abstract: Process for the preparation of exocellular biopolymers having a thickening effect in aqueous media by aerobic culture of microorganism strains forming the biopolymers in an aqueous nutrient medium present as disperse aqueous phase in a water/oil emulsion (W/O-emulsion) stable under fermentation conditions using W/O emulsifiers for emulsion formation and stabilization, in which the oil phase is used in quantities below 50% by volume, based on the mixture as a whole, and fatty acid dialkanolamides are used as the W/O emulsifiers.