Abstract: A diffusion sampler includes a vessel which has at least one inlet opening exposed to the gas to be investigated and which has a moderating zone. In its interior, the vessel has a collecting region provided with a collecting medium as well as a conversion region for converting the gas into substances which can be taken up by the collecting medium. The diffusion sample is improved in that its detection sensitivity is increased and that the collecting region as well as the converting region are provided with large areas in a manner adapted to the geometry of the vessel so that a smaller and more manipulable configuration is obtained. In addition, long-term dosimetry is made possible. For this purpose, the moderating zone is configured as a permeable barrier from which the converting region as well as the collecting region extend and determine the diffusion path in the entire interior of the vessel with each region being applied to a carrier.

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 process and an apparatus for the detection of molecular or ionic species, comprising:(a) contacting a gaseous or liquid medium containing the species to be detected with a film comprising at least one monomolecular layer of amphiphilic compound chosen from among the tetracyanoquinodimethane (TCNQ) charge transfer complexes and the tetracyanoquinodimethane (TCNQ) salts, which conduct electricity or are precursors of electricity conducting charge transfer complexes and(b) determining the variation of one of the physical properties of the film.It is in particular possible to use layers of TCNQ alkyl-pyridinium, TCNQ alkyl-quinolinium, for detecting iodine, nitrogen oxides and fluoric compounds.

Abstract: A detection system for detecting the presence of predetermined compounds in a sample. The system comprises a sample injection means, a chromatographic column, a conversion means and one or more specific gas detectors. The conversion means transforms the column effluent to combustion products in the gas phase, after which those combustion products are transferred to the specific gas detectors. In one embodiment for detecting nitrogen compounds, the conversion means includes an oxygen-rich flame, a means to control the flame to have a temperature in the range 600.degree.-1700.degree. C., means to inject the column effluent into the flame, and an input port for transferring the flame effluent to a specific nitrogen detector.

Abstract: A structure and method for sensing oxides of nitrogen in a gas. The gas is first passed through an oxidation catalyst and any reducing species in the gas are oxidized. The output gas from the oxidation catalyst is received by a sensor which generates an output responsive to oxides of nitrogen because the sensor has been isolated from any reducing species in the gas.

Abstract: A gas analyzer for determining the concentration of the oxides of nitrogen in a sample gas is provided. The analyzer is particularly adapted for analyzing the exhaust from an internal combustion engine. In one embodiment, the analyzer comprises a sample chamber and a reference chamber. An arrangement is provided for delivering sample gas containing the lower oxide of nitrogen (NO) to the sample chamber and a quantity of ozone (O.sub.3) for reacting with this oxide of nitrogen and producing a chemiluminescence. After the chemiluminescence is completed, the sample gas is discharged to the reference chamber. A sample photodiode is disposed adjacent to the sample chamber for receiving light emitted from the sample chamber and producing a sample signal representative of the total photoemissivity of the sample gas.

Abstract: This invention is directed to the use of specific polymethine dyes for staining fixed biopsy specimens of hematopoietic origin consisting of blood, bone marrow and lymph node cells for purposes of identifying and enumerating the stained cells when viewed under dark field illumination. The polymethine dyes, e.g. Astrazon Red Violet FRR, stain the lymphocyte subpopulations distinct colors capable of being viewed under dark field illumination for purposes of distinguishing one stained cell from another. This method of staining and the compositions thereof represents an advance in the art of lymphocyte subpopulation identification which was achieved heretofore primarily by using monoclonal antibody techniques.

Abstract: A detection system for detecting the presence of predetermined compounds in a sample. The system comprises a sample injection means, a chromatographic column, a conversion means and one or more specific gas detectors. The conversion means transforms the column effluent to combustion products in the gas phase, after which those combustion products are transferred to the specific gas detectors. In one embodiment for detecting nitrogen compounds, the conversion means includes an oxygen-rich flame, a means to control the flame to have a temperature in the range 600.degree.-1700.degree. C., means to inject the column effluent into the flame, and an output port for transferring the flame effluent to a specific nitrogen detector.

Abstract: A device for treating water to reduce the concentration of cations or anions therein includes a water-tight container (4) of flexible material, designed to be able to lie substantially flat (FIG. 3) when empty and having an aperture (5) for the introduction of liquid, a strainer (7) extending across the aperture, and a closure (6) for the aperture, and a quantity of ion-exchange material (b 8) occupying a minor proportion of the available interior volume of the container. A soil extraction outfit and a soil testing outfit are described, which incorporate the water treatment device.

Abstract: Chemiluminescence is detected in a luminol solution free of metal ions flowing through a porous material to indicate the presence of certain nitrogen-containing gases. Continuous monitoring of atmosphoric gases is possible through use of the described methods and related apparatus.

Abstract: A gas sensor element comprising a film of a semiconducting compound of formula I supported by a non-conductive substrate, the film being disposed between conductors for supplying a current to the film and withdrawing a current therefrom. ##STR1## in which: M represents 2H, Mn, Fe, Co, Ni, Cu, Hg, Cd, Pb, Pt or Pd;R.sub.1 represents H, CH.sub.3, Cl, Br, I, CN, CO.sub.2 H, COOC.sub.n H.sub.2n+1, CONH.sub.2 or NO.sub.2 ;R.sub.2 represents H or CH.sub.3 ; andR.sub.3.sup.a and R.sub.3.sup.b, which may be identical or different represent H, NO.sub.2, Cl, CO.sub.2 H or CH.sub.3 ;provided that when M represents cobalt at least one of R.sub.1, R.sub.2, R.sub.3.sup.a and R.sub.3.sup.b is other than hydrogen.

Abstract: A gas analyzer for determining the concentration of the oxides of nitrogen in a sample gas is provided. The analyzer is particularly adapted for analyzing the exhaust from an internal combustion engine. The analyzer comprises a sample chamber and a reference chamber. An arrangement is provided for delivering sample gas containing the lower oxide of nitrogen (NO) to the sample chamber and a quantity of ozone (O.sub.3) for reacting with this oxide of nitrogen and producing a chemiluminescence. After the chemiluminescence is completed, the sample gas is discharged to the reference chamber. A sample photodiode is disposed adjacent to the sample chamber for receiving light emitted from the sample chamber and producing a sample signal representative of the total photoemissivity of the sample gas.

Abstract: A steam and gas turbine combined cycle plant STAG* employs a catalyst in a heat recovery steam generator to react injected ammonia with NO.sub.x from the combustor of the gas turbine to reduce atmospheric emission of NO.sub.x from the system. Rapid control of ammonia injection is achieved using a prediction of the NO.sub.x being generated in dependence upon the operating conditions of the combustor. A trimming signal from a measurement of NO.sub.x being emitted from the heat recovery steam generator downstream of the catalyst is employed to complete the NO.sub.x control loop. Compensation is provided to relate the measured NO.sub.x downstream of the catalyst with the NO.sub.x in the output of the gas turbine taking into account the catalyst efficiency.

Abstract: A steam and gas turbine (STAG) plant employs a catalyst in a heat recovery steam generator to react injected ammonia with NO.sub.x from the combustor of the gas turbine to reduce atmospheric emission of NO.sub.x from the system. Rapid control of ammonia injection is achieved using a prediction of the NO.sub.x being generated in dependence upon the operating conditions of the combustor. A trimming signal from a measurement of NO.sub.x being emitted from the heat recovery steam generator downstream of the catalyst is employed to complete the NO.sub.x control loop.