Abstract: The selectivity of response of resistive gas sensors to specific gases or vapors is improved by the selection of specified gas-sensitive materials which are not previously known for the applications described, which include detection of hydrocarbons in the presence of CO, H.sub.2 S, SO.sub.2, chlorine, NO.sub.2, CO.sub.2 (especially in low concentrations), CFC's, ammonia, free oxygen by determination of partial pressures, and numerous organic gases and vapors.

Abstract: Reagents, immunoassay methods, and kits for detecting the presence or amount of trichloroethylene or perchloroethylene in a sample. Reagents include antibodies, immunogens for preparing antibodies, and assay conjugates. The immunogens elicit high affinity antibodies to trichloroethylene. The antibodies have minimal crossreactivity to other halogenated and aromatic hydrocarbons. The assay conjugates provide for sufficient binding of the antibody to the conjugate with maximum inhibition of that binding by free trichloroethylene and perchloroethylene in the sample. The reagents are useful in immunoassays to detect trichloroethylene and perchloroethylene, especially in environmental samples. Kits contain antibodies specific for trichloroethylene and perchloroethylene and assay conjugates.

Abstract: The invention provides a gas sensor for selective detection of hydrocarbons in low-oxygen gases, having a capacitive element and a gas-permeable sensitive layer as a dielectric. The sensitive layer is a precious-metal-doped zeolite which has a regular crystalline structure made of primary pores whose diameter is in the order of the gas-kinetic diameter of the gas molecules to be detected.

Abstract: A selective catalytic material is used to catalyze selective oxidation of unsaturated hydrocarbons, e.g., olefins, in the presence of carbon monoxide. The catalytic material comprises phosphated ceria containing from 0.1 to 20, preferably from 1 to 5, percent by weight phosphate component (calculated as elemental phosphorus). The phosphated ceria may be made by mixing particles of ceria and a solution containing phosphates to disperse the desired amount of phosphate component on the ceria and calcining the particles after separation of them from the solution. The resulting selective catalytic material is contacted under oxidizing conditions with a gas stream containing an oxidant, e.g., air, carbon monoxide and one or more unsaturated hydrocarbons.

Abstract: A method of determining or predicting a value P.sub.x of a property of a feed X to a steam cracking process or yield of said process, which method comprises measuring the absorption D.sub.ix of said material at more than one wavelength in the region 600-2600 nm, comparing signals indicative of said adsorptions or a mathematical function thereof with signals indicative of absorptions D.sub.im or mathematical function thereof at the same wavelength for a number of standards S in a bank for which the said property or yield P is known, and choosing from the bank at least one standard S.sub.m with property P.sub.m said standard having the smallest average value of the absolute difference at each wavelength i between the signal for the material and the signal for the standard S.sub.m to obtain P.sub.x, with averaging of said properties or yields P.sub.m when more than one standard S.sub.m is chosen. If desired the method can be used as such to control the steam cracking process by comparison of P.sub.

Abstract: An assay method incorporating at least two different chemiluminescent compounds for detection and/or quantitation of at least two substances in a test sample is described. The synthesis of chemiluminescent reagents or conjugates for use in such methods as well as kits incorporating such reagents are also disclosed. The assays have particular application in the field of clinical diagnostics.

Abstract: An apparatus for on-line measuring physical property data of hydrocarbon products such as octane number, cetane number, density, vapour pressure and the like or gasoline/alcohol ratio, comprising means for providing (N)IR radiation in a predetermined spectral range; means for transmitting light at selected wavelengths in the (N)IR spectral region; means for delivering light from said transmitting means to a hydrocarbon product line; means for allowing an optical path length in the hydrocarbon product line; means for detecting the light transmitted through the said optical path; means for providing the obtained signal to be input to processing equipment for spectral analysis and correlating the spectral data to the physical property data of hydrocarbon products such as octane number, cetane number, density, vapour pressure and the like or gasoline/alcohol ratio.

Abstract: The present invention is a method to determine the chemical concentration of one or more of a number of the constituent classes of a feed to a catalytic cracking process. These constituent classes which are referred to as "lumps", include 14 different molecular types in 4 different boiling range fractions. A specific lump will include all individual molecular components which are expected to react in a similar way in the catalytic cracking unit.

Abstract: The present invention relates to a process for indicating the presence of organic vapors comprising the steps of determining the color, absorption or emission spectra of a Pt--Pt double-complex salt of platinum or a neutral platinum complex in the absence of organic vapor, exposing said double-complex salt of platinum or a neutral platinum complex to a gaseous environment, determining the color, absorption or emission spectra of said double-complex salt of platinum or a neutral platinum complex after exposure to said gaseous environment, and comparing the color, absorption and/or emission spectra of said double-complex salt of platinum or a neutral platinum complex in the absence of organic vapor with the color, absorption and/or emission spectra of said double-complex salt of platinum or a neutral platinum complex after exposure to said gaseous environment to determine if there is a difference in the color, absorption and/or emission spectra.

Abstract: Systems and methods for material analysis are disclosed in which an organic sample (e.g., a foodstuff, tissue sample or petroleum product) is illuminated at a plurality of discrete wavelengths which are absorbed by fatty acid and fatty acid oxidation products in the sample. Measurements of the intensity of reflected or absorbed light at such wavelengths are taken, and a analysis of absorbance ratios for various wavelengths is performed. Changes in the reflection ratios are correlated with the oxidative state of fatty acids present in the material.

Abstract: There is provided a precisely quantitative measurement method of a hydrocarbonaceous polymerization inhibitor component in a fluorine-containing olefinic monomer, which inhibitor component is contained in the monomer in such a trace amount that it cannot be detected by a gas chromatography. In the method, an ultraviolet absorption spectrum of a concentrated sulfuric acid is measured after it is contacted with the fluorine-containing olefinic monomer and the concentration of the polymerization inhibitor is obtained based on an absorbance of the spectrum and a calibration curve which has been beforehand obtained.

Abstract: A process for the measurement of the level of radioactivity of a solid by contacting the solid with a chemically stable reactant fluid. The reactant fluid is converted by nuclear radiation to a chemically stable product fluid to an extent dependent upon the radioactive content of the solid. The amount of the reactant fluid converted into the product fluid is detected in order to determine the level of radioactivity of the solid.

Abstract: A method and apparatus for detecting the presence of a vapor of an alkyl ester of phosphoric acid, particularly tributylphosphate, in ambient air. A sample of ambient air is heated to convert any alkyl ester of phosphoric acid to an alkene. The heated sample of air is then passed to a sample loop. Carrier air periodically carries a fixed volume of sample from the sample loop through a chromatographic column to a photoionization detector which detects the presence and amount of the alkene in the sample.

Abstract: A process is described for generating conjugates of lipids and biologically active agents to produce compositions having therapeutic utility, such as drug delivery vehicles. The process involves mixing the reactive lipid with an appropriate amount of diketene to form an acetoacetylated lipid which is then isolated, dissolved in a suitable medium, and mixed with a nucleophilic-containing biologically active agent to form a biologically active agent-lipid conjugate. Alternatively, the acetoacetylated lipid can be mixed with a polyamine to form a cationic lipid.

Abstract: A method for detecting the presence of a vapor of an alkyl ester of phosphoric acid, particularly tributylphosphate, in ambient air. A sample of ambient air is heated to convert any alkyl ester of phosphoric acid to an alkene. The heated sample of air is then passed to a sample loop. Carrier air periodically carries a fixed volume of sample from the sample loop through a chromatographic column to a photoionization detector which detects the presence and amount of the alkene in the sample.

Abstract: A device for detecting the presence or concentration of an analyte, a method of making the device, and a method of detecting the presence or concentration of an analyte. The invention features one or more supports, such as beads, which carry a thin film of polymer substrate. The polymer substrate has a sensing reagent and a porous matrix. The sensing reagent alters the optical properties of the polymer substrate in the presence of analyte.

Abstract: A method for the selective detection of liquid phase hydrocarbons in the C.sub.6 -C.sub.16 range includes a matrix comprising a silicone polymer having dispersed therein a conductive carbon black filler of high structure and comprises signaling the presence of hydrocarbon liquid phase when the electrical resistivity of the sensor increases to a preselected threshold level intermediate the vapor and liquid phase resistivities.

Abstract: A quantitative method including separating a mixture of olefins, aromatics, and saturates by supercritical fluid chromatography to obtain an eluent stream that over a first time period contains a mixture of olefins and saturates, and over a second time period contains aromatics, and passing the eluent first to an ultraviolet absorption detector (UV). Importantly, the eluent is irradiated in the UV detector at a wavelength capable of producing an ultraviolet absorbance response of olefins that is independent of specific olefins present, and preferably is substantially similar to a mass detector response for olefins. From a combination of UV and mass response, the mass of the olefins in the mixture of olefins and saturates can be determined. Thereafter, the eluent is passed to a mass detector whereby the mass of the mixture of saturates and olefins is determined and then the mass of the aromatics is determined.

Abstract: A method and apparatus for assessing the odor intensity of combustion gas produced from an internal combustion engine in which the odor intensity of combustion gas is obtained from the pH-value of an aqueous solution prepared from odor-producing substances, based on a predetermined relationship between pH-value and odor intensity. The odor intensity thus obtained strongly correlates with organoleptically evaluated odor intensity. Since the odor intensity of the gas is determined from the pH-value, the precision and the reliability of the odor intensity measurement are enhanced.

Abstract: A bismuth molybdate gas sensor which provides stable sensitivity to gases such as alcohol, ketones, alkenes, and long chain alkanes is disclosed. Sensors comprising a mixture of the Bi.sub.2 Mo.sub.3 O.sub.12 and Bi.sub.2 MoO.sub.6 phases of bismuth molybdate; or, bismuth iron molybdate are particularly effective. The bismuth molybdate mixture; or, the bismuth iron molybdate may be deposited as a thin film on a substrate or may take the form of a sintered powder.

Abstract: A hydrocarbon gas detection system utilizes a heat chamber or oven to maintain the system at a temperature that will support cracking of hydrocarbon gases. A gas chamber which is located inside the oven is used to contain the flow of gases under analysis and to pass these gases over a first temperature sensing device. A catalyzing material is associated with the first temperature sensing device, either by placing it very near the temperature sensing device or by coating the temperature sensing device with the catalyzing material. A second temperature sensing device is located inside the heat chamber or oven, either outside the gas chamber, or inside the gas chamber, but separated from the first temperature sensing device. The output of the first and second temperature sensing devices extend outside of the furnace to measurement and/or display instrumentation. With this system, the gas sample under analysis is passed through the gas chamber and brought into contact with the first temperature sensing device.

Abstract: Methods and apparatus for analyzing a hydrocarbon sample are provided. The apparatus employs a highly polar column to separate the aromatics from non-aromatic components. The non-aromatic effluent from the highly polar column is passed to a 13X MSCOT column and a first less polar column. In a second configuration the highly polar column is backflushed into a second less polar column. The 13X MSCOT column separates isoparaffins, normal paraffins, and naphthenes by carbon number while the first less polar column individually separates the paraffins and naphthenes. The second less polar column is employed to separate individual aromatics.The method for analyzing a hydrocarbon sample separates the aromatics of the sample from the isoparaffins, normal paraffins, and naphthenes. The isoparaffins, normal paraffins, and naphthenes are then separated and detected by carbon number. Simultaneously, the individual non-aromatic components are separated and detected.

Abstract: A method is provided for quantitatively determining the amount of unsaturation in butyl and EPDM rubbers using a gel permeation chromatograph in combination with an ultraviolet detector. Placement of a differential refractive index detector in series with said ultraviolet detector provides a method for the simultaneous measurement of the amount of unsaturation, the molecular weight distribution and the amount of antioxidant in said rubbers.

Abstract: A method and/or system for rapidly determining the average composition and characteristics of a hydrocarbon mixture comprising thermally cracking the mixture to form a gaseous product, measuring the ratios or proportions of the individual components in the gaseous product, and comparing the ratios of the components present in the gaseous products with a known property of the hydrocarbon feed mixture and obtaining the average composition and intrinsic properties of the hydrocarbon feed.

Abstract: A method of analysis by high performance liquid chromatography is provided for obtaining an analysis of three components, namely acyclic paraffins, cycloparaffins and unsaturates, present in a liquid hydrocarbon mixture. The method comprises introducing a sample of the mixture to be analyzed into an unsaturates-selective column, passing the eluents from the unsaturates-selective column to a second column, eluting the separated components from the second column, detecting the presence of paraffins and naphthenes in the effluent from the second column, eluting the separated components from the unsaturates-selective column, and detecting the presence of unsaturates in the effluent from the unsaturates-selective column. The unsaturates-selective column is a silver-modified ion exchange column. The second column is a slurry packed column packed with a microparticulate material. The detector is a dielectric constant detector.

Abstract: Articles comprise transition metal double-complex salts which contain arenyl isonitrile ligands derivatized with long aliphatic chains, the cation being a tetrakis isonitrile platinum ion and the anion being a tetracyanopalladate ion. These double-complex salts exhibit novel vapochromic effects and are useful as personal and badge monitors, threshold monitors, optical waveguide sensors, chemical field effect transistors, and in related monitoring applications.

Abstract: A desired unreacted monomer concentration is maintained in the reaction effluent removed from a polymerization reactor by manipulating the catalyst feed rate to the polymerization reactor.

Abstract: A desired unreacted monomer concentration is maintained in the reaction effluent removed from a polymerization reactor by manipulating the catalyst feed rate to the polymerization reactor based on a non-linear control signal derived from a comparison of actual and desired unreacted monomer concentration.

Abstract: A reference element for a catalytic gas sensor with improved life in the presence of combustible gases is described. The sensor comprises a filament such as a platinum-iridium alloy coated with a layer of titanium dioxide. The coating typically contains a high temperature stable inorganic binder such as aluminum oxide. The filament can be in coil-form pre-encased in a glass bead. Such sensor has long term stability in the presence of combustible organic gases such as alkenes, alkadienes, alkynes, and epoxide containing hydrocarbon gases, for example. Sensors containing such elements have particular utility in the area of mining and oil drilling environments, as well as industrial, safety, and commercial applications.

Abstract: Apparatus for detecting the concentration of a gas by measuring the amount of mercury vapor generated when the gas is passed through a mercuric oxide bed. The apparatus includes a body having a central bore therein with a quartz rod at one end for directing ultraviolet light from a source through the central bore. A second quartz rod at the opposite end of the central bore directs the ultraviolet light to a detector coupled to an electronics circuit for analysis purposes. A fitting coupled to the body has a gas inlet port and a passage from the port to the central bore of the body. The mercuric oxide bed is across the passage so that the gas, in passing through the bed, causes mercury vapor to be generated and to pass into the central bore of the body. The amount of mercury vapor is measured by its spectral absorption in the ultraviolet range when the mercury vapor is in the central bore of the body.

Abstract: A sensing apparatus and method for qualitatively and quantitatively analyzing small amounts of selected oxidizable gases in a carrier gas including the associated electronic circuitry is described. The apparatus preferably includes two semi-conductor type sensing elements in electrical parallel so that the difference in resistance of the two sensors can be detected, which can be of the N or P type and which decrease or increase in electrical resistance as a function of the concentration of an oxidizable gas. Also, a method for determining fruit maturity and ripeness by the detection of ethylene in the internal atmosphere of a fruit is described which preferably uses the apparatus with the semi-conductor type sensing elements, but can use other variable resistance type gas sensing means.

Abstract: In a selective hydrogenation process wherein at least two catalyst beds in series are utilized, the temperature of the feed stream flowing to the first catalyst bed and the temperature of the feed stream flowing from the first catalyst bed to the second catalyst bed are controlled using a combination of feed forward and feed back control. The feed forward control is based on the change in a process variable during a specified period of time. The feed back control is based on a comparison to the actual concentration of acetylene in the product stream flowing from the second catalyst bed to the desired concentration of acetylene in the product stream flowing from the second catalyst bed.