Abstract: The present invention relates generally to the field of microelectronics, and more particularly to a structure and method of forming a biosensor having a nucleotide attracting surface tailored to reduce false detection of nucleotides and enabling optical detection of nucleotides. The biosensor may include an analyte-affinity layer on an upper surface of a dielectric layer. The analyte-affinity layer may include a plurality of cylindrical gold portions with dimensions tailored for a target analyte. A distance between adjacent portions of the plurality of portions may range from approximately 50% of a length of a target analyte to approximately 300% of a length of a target analyte. The plurality of portions of the analyte-affinity layer have an upper surface with a diameter ranging from approximately 3 nm to approximately 20 nm.

Abstract: The present invention relates generally to the field of microelectronics, and more particularly to a structure and method of forming a biosensor having a nucleotide attracting surface formed to reduce false detection of nucleotides and enabling electrical detection of nucleotides. The biosensor may include an analyte-affinity layer on an upper surface of a substrate. A conductive layer may extend a length of the substrate below and in contact with the analyte-affinity layer. The conductive layer may be electrically connected to one or more transistors. The analyte-affinity layer may have dimensions tailored for a target analyte. A distance between a first analyte-affinity layer and a second analyte-affinity layer may range from approximately 50% of a length of a target analyte to approximately 300% of a length of a target analyte. The analyte-affinity layer may have an upper surface with a diameter ranging from approximately 3 nm to approximately 20 nm.

Abstract: A method of detecting at least one of an analyte or a condition of a fluid within a subterranean formation includes operably coupling a radiation source to at least one optical fiber coupled to a sensor having optically sensitive materials including at least one of chromophores, fluorophores, metal nanoparticles, or metal oxide nanoparticles dispersed within an optically transparent permeable matrix material. The sensor is contacted within a wellbore with a fluid and the fluid is passed through at least a portion of the sensor. Electromagnetic radiation is transmitted from the radiation source through at least one optical fiber to the sensor and at least one of an absorbance spectrum, an emission spectrum, a maximum absorption intensity, or a maximum emission intensity of electromagnetic radiation passing through the sensor after contacting at least some of the optically sensitive materials with the fluid is measured.

Abstract: A method for preparing hydrophobic gold nanoparticles includes adding 1,2-dichlorobenzene as a solvent to gold precursor and using oleylamine and oleic acid with volume ratio of 7.5:2.5 to 5:5 as surfactants. The size of the prepared gold nanoparticles can be controlled over a broad range and may be utilized in various fields such as bio-imaging, photonic crystallization, sensors, organic catalysts, surface enhanced raman spectrum, electronic devices, etc. Further, a method for colorimetric detection of a strong acid uses hydrophilic nanoparticles that are phase transited from the prepared hydrophobic gold nanoparticles. Up to 5 ppm of low content hydrochloric acid can be detected utilizing phase transited hydrophilic nanoparticles in the colorimetric detection method, and the gold nanoparticles that were used in the detection of strong acid can be reused without loss of activity through neutralization with bases.

Abstract: The disclosure relates to a plasmon resonance-based method for gas sensing in a gas stream utilizing a gas sensing material. In an embodiment the gas stream has a temperature greater than about 500° C. The gas sensing material is comprised of gold nanoparticles having an average nanoparticle diameter of less than about 100 nanometers dispersed in an inert matrix having a bandgap greater than or equal to 5 eV, and an oxygen ion conductivity less than approximately 10?7 S/cm at a temperature of 700° C. Exemplary inert matrix materials include SiO2, Al2O3, and Si3N4 as well as modifications to modify the effective refractive indices through combinations and/or doping of such materials. Changes in the chemical composition of the gas stream are detected by changes in the plasmon resonance peak. The method disclosed offers significant advantage over active and reducible matrix materials typically utilized, such as yttria-stabilized zirconia (YSZ) or TiO2.

Abstract: A device for gas analysis includes a detector tube (2) and can be used in the area of explosive or combustible gases. A filter material, which consists of a granular, porous material and has an impregnation for absorbing toxic gases, is provided between the detector tube (2) and a pump (6).

Abstract: A sensor material of the type comprising a long-decay photoluminescent, protonable dye embedded in a suitable polymeric matrix, is used for generating a specific optical response to two different analytes present in a sample, thus allowing selective determination of the two analytes in the sample. Also described is a method for the simultaneous sensing of a first and second analyte in a sample. The method comprises the steps of irradiating a sensor material of the type comprising a long-decay photoluminescent protonable dye embedded in a suitable polymeric matrix with light of one or two wavelengths, determining photoluminescence intensity and lifetime signals originating from the sensor, and correlating the photoluminescence intensity signal with a concentration of the first analyte and the photoluminescence lifetime signal(s) with the concentration of the second analyte.

Abstract: Devices and methods for measuring the acidity of airborne matter are provided. A filter can be impregnated with an indicator dye which changes color in response to changes in acidity. After the sample passes through the filter, the filter can be analyzed using UV-visible spectrometry.

Abstract: Disclosed is a pigment that changes color upon exposure to hydrogen sulfide gas. The pigment may be ground or otherwise reduced to small particles and used in coatings, dyes, paints or inks. Potential applications for paints and inks include the production of warning indicators for the presence of hydrogen gas in areas where such presence may pose a hazard. Warning decals may be printed with pigmented ink and posted in areas of potential hydrogen hazard. In the presence of hydrogen sulfide gas, the decals can display a warning by causing a change in the color of a printed message. Objects may also be coated with pigmented paints so that if a hydrogen sulfide leak occurs from within or nearby the object, the color of the object changes to provide a warning of the presence of leaked hydrogen sulfide. Example applications of such painted objects include any industrial process containing hydrogen sulfide.

Abstract: The present invention relates to a method of detecting soil nutrients or soil nutrients in soil from reflected light, and also includes systems for the measurement, calculation and transmission of data relating to or carrying out that method.

Abstract: Articles of manufacture and methods of making and using same concern a container having an internal space and a passivated internal metal surface. The container contains a composition of an acid gas and a balance gas contained within the internal space and in contact with the passivated internal metal surface. The stability of the acid gas concentration over time is enhanced.

Abstract: Disclosed is a method for removing minerals from a cellulosic biomass. For example, the biomass may be prewashed with an acid solution and rinsed with water to remove minerals prior to acid saccharification. The removal of minerals may reduce overall acid requirements, and decrease pretreatment costs.

Abstract: Systems and methods are disclosed for measuring sulfur trioxide/sulfuric acid content of flue gas. A probe is provided that extracts two separate lines of gas samples simultaneously from the flue gas. One of the two lines is dynamically spiked with a known quantity of sulfur trioxide, preferably generated in the probe. A comparison of sulfur trioxide/sulfuric acid content measurements from the spiked and unspiked lines helps identify and adjust for inherent biases in the measuring system. Also disclosed are catalyst structures and methods for use thereof for generating sulfur trioxide at known concentration.

Abstract: Methods for determining chlorine demand in water are provided. One method comprises (a) providing a test water sample containing at least one contaminant and a source of chlorine and a source of bromide; (b) heating the test water sample for a suitable time and temperature sufficient to substantially oxidize the at least one contaminant in the test water sample; and (c) determining the content of residual chlorine present in the test water sample.

Abstract: Systems and methods are disclosed for measuring sulfur trioxide/sulfuric acid content of flue gas. A probe is provided that extracts two separate lines of gas samples simultaneously from the flue gas. One of the two lines is dynamically spiked with a known quantity of sulfur trioxide, preferably generated in the probe. A comparison of sulfur trioxide/sulfuric acid content measurements from the spiked and unspiked lines helps identify and adjust for inherent biases in the measuring system. Also disclosed are catalyst structures and methods for use thereof for generating sulfur trioxide at known concentration.

Abstract: The present invention provides compounds of Formula I: wherein: R1 is a label (e.g., a detectable groups; an anti-tumor agent)s; L is present or absent and when present is a linking group; and x represents an integer from 1 to 10; or a pharmaceutically acceptable salt thereof. the compounds are useful for, among other things, identifying cysteine sulfenic acids in proteins and monitoring oxidative damage in proteins and cells.

Abstract: A method of detecting a substance present in a gas or a gas mixture using SIFT-MS technology comprising the steps of inducing a supply of alkoxymethyl cations into the inlet of the flow tube, reacting a sample of the as with the alkoxymethyl cations, analysing the reacted gas sample, and calculating the concentration of trace levels of molecules containing heteroatoms in the reacted gas sample.

Abstract: Disclosed is a pigment that changes color upon exposure to hydrogen sulfide gas. The pigment may be ground or otherwise reduced to small particles and used in coatings, dyes, paints or inks. Potential applications for paints and inks include the production of warning indicators for the presence of hydrogen gas in areas where such presence may pose a hazard. Warning decals may be printed with pigmented ink and posted in areas of potential hydrogen hazard. In the presence of hydrogen sulfide gas, the decals can display a warning by causing a change in the color of a printed message. Objects may also be coated with pigmented paints so that if a hydrogen sulfide leak occurs from within or nearby the object, the color of the object changes to provide a warning of the presence of leaked hydrogen sulfide. Example applications of such painted objects include any industrial process containing hydrogen sulfide.

Abstract: The present application describes a reagent system for detecting presence of aldehyde in a sample that includes (i) Component A, which includes bisulfite, pararosalinine, and hydrochloric acid; and (ii) Component B, which includes a solution of hydroxide, wherein the Component A has a pH of from about 1.4 to 1.6.

Abstract: A method of using an inert fluorescent tracer in a system that contains liquids in contact with solid surfaces and wherein said system contains a corrosive environment, is described and claimed, as is a method of using an inert fluorescent tracer to trace the corrosive material itself. Combinations of inert fluorescent tracers in corrosive materials are also described and claimed.

Abstract: The present invention is a rapid method of determining the concentration of the major components in a chemical stream. The present invention is also a simple, low cost, device of determining the in-situ concentration of the major components in a chemical stream. In particular, the present invention provides a useful method for simultaneously determining the concentrations of sodium hydroxide, sodium sulfide and sodium carbonate in aqueous kraft pulping liquors through use of an attenuated total reflectance (ATR) tunnel flow cell or optical probe capable of producing a ultraviolet absorbency spectrum over a wavelength of 190 to 300 nm. In addition, the present invention eliminates the need for manual sampling and dilution previously required to generate analyzable samples.

Abstract: This invention relates to methods and apparatus for detecting, quantifying, and/or identifying trace quantities of an anion in the presence of an excess of another anion. One apparatus comprises a sample loop having a first end adapted to be connected to a sample-injection device and a second end adapted to be connected to an inlet of a first separator. An outlet of the first separator has connections to a first waste port and to an inlet of a first anion suppressor. An outlet of the first anion suppressor is connected to a first end of a concentrator and alternatively to waste, the concentrator connected at a second end to a second waste port and alternatively to a pump. The first end of the concentrator is alternatively connected to a second separator inlet, and the second separator is connected at an outlet thereof to an inlet of a second anion suppressor; and an outlet of the second anion suppressor is connected to a mass spectrometer.

Abstract: A method and apparatus for sulfate analysis in a sample are provided. A portion of the sulfate contained in the sample is converted to sulfur dioxide, and at least a portion of the sulfur dioxide can be determined. The amount of sulfur dioxide determined can be used to quantify the amount of sulfate in the sample.

Abstract: A systematic treatment of chemical equilibria is used to determine the average molecular weight of the Suwannee River fulvic acids directly from aqueous solutions. Additionally, parameters such as equilibrium constant and reaction stoichiometry can be calculated. The measurement of the initial mass of unknown analytes is not needed for the determination.

Abstract: The invention relates to a method for qualitative, semi-quantitative or quantitative determination of at least two analytes in an aqueous sample containing or suspected of containing the analytes, which method comprises the steps of: (i) providing a flow matrix comprising a separation zone extending in a first dimension thereof, and a detection zone extending in the first dimension in a spaced parallel relationship with the separation zone, the detection zone comprising an immobilized reagent capable of capturing the analytes through biospecific interaction therewith, (ii) applying the sample to the flow matrix at or upstream of the separation zone, (iii) initiating a first essentially aqueous fluid flow in the flow matrix along the separation zone in the first dimension to transport the analytes through the separation zone to be separated therein, (iv) interrupting the first fluid flow and initiating a second essentially aqueous fluid flow in a second dimension of the flow matrix substantially transverse

Abstract: Embodiments of the invention are directed to microfluidic devices. In one embodiment, a microanalysis chip comprises a body having at least one transfer-separation channel with a channel bottom that has a bottom opening. The transfer-separation channel terminates in a discharge aperture.

Abstract: Detection of an evolving or diffusing gaseous substance emanating from an irradiated or thermolyzed layer of polymeric composition in semiconductor processing or similar processes is disclosed. The evolving or diffusing gaseous substance is detected by spatially disposing from the irradiated or thermolyzed layer a detector layer that includes a compound having leaving groups that are sensitive to the gaseous substance being detected.

Abstract: The invention relates to a method for solid-phase microextraction and analysis of substances in a carrier fluid, in which a collector is brought into contact with the stirred fluid containing the substances for a sufficient time and is then subjected to a solid-phase extraction directed at at least one substance adhering to the collector, and desorbed substances are transported for analysis by means of a carrier gas, in which the carrier fluid containing the substances is stirred in a receptacle of a magnetic stirrer by means of a coated magnetic stirring element as the collector, and/or the carrier fluid is made to move intimately relative to the collector by means of ultrasound, and then the stirring element is placed in a solid-phase extraction device.

Abstract: A system and apparatus for analyzing stack gas for total reduced sulfur. The gas is withdrawn from a stack through a probe, filtered and regulated to a known temperature. The gas is then passed through a scrubbing column to remove sulfur dioxide and split into first and second portions. The first portion is oxidized to covert total reduced sulfur compounds to SO2, and the gas is then passed to an electrochemical sensor for SO2 which is maintained at a temperature at least equal to the temperature of the regulated gas. The second portion of the scrubbed gas is passed through an electrochemical sensor for oxygen which is maintained at substantially the same temperature as the sensor for SO2.

Abstract: The invention relates to the study and the manufacture of lubricants used in particular in diesel engines. According to the invention, the neutralization capacity of a lubricant comprising detergent additives is determined by a method which consists in reacting, in a leaktight tank, at a constant temperature, the bases contributed by the additives present in a lubricant film of known mass with a predetermined amount of a liquid acid and in recording, as a function of the time, the values of the pressure within the leaktight tank, and in then determining, from the recorded values of the pressure, at lest one of the following three characterizing parameters: an initiation period for the reaction, a neutralization potential and a reaction rate. The invention finds its application in research and control laboratories of manufacturers of lubricants and in those of engine manufacturers.

Abstract: Monitoring techniques have been developed for direct/indirect determination of metal etching bath components and for managing their replenishment. The disclosed methods have been successfully employed to make TiW etching a robust process that provides minimized and controlled undercutting of ball limited metallurgy and mechanical reliable C4s. A metal etching solution is monitored and replenished by measuring the sulfate concentration of a hydrogen peroxide, soluble salt, and soluble EDTA salt etchant. Turbidimetric titration conditions are used to measure and compare opaqueness of liquids by viewing light through them and determining how much light is cut off. Additional sulfate is added to maintain the sulfate concentration. Water and/or fresh etchant is added to compensate for evaporation or drag.

Abstract: An improved test is described for chlorine in pool and spa water where potassium monopersulfate is used as an oxidizing agent and DPD is used as an indicator. N,N-bis(hydroxyethyl)-2-aminoethane sulfonic acid or bicine is used to mask or eliminate the potassium monopersulfate so that it does not interfere with the DPD indicator. The test is very reliable and accurate.

Abstract: A process for extracting inorganic ionic contaminants from a front surface of a silicon wafer for chemical analysis. The wafer is placed in a container upon a support which holds the wafer in a generally level orientation and isolates the wafer to inhibit air circulation over the front surface. Air circulation can introduce contaminants to the extraction fluid, causing a false measurement of contaminants on the wafer. A layer of extraction fluid is deposited upon only the front surface of the wafer and held for a period of time so that contaminants on the front surface are extracted into the layer of fluid. A portion of the layer of fluid is collected by a sampling device for subsequent analysis.

Abstract: The instant invention provides for a method of inhibiting prenyl-protein transferases and treating cancer which comprises administering to a mammal a prenyl-protein transferase inhibitor which is efficacious in vivo as an inhibitor of geranylgeranyl-protein transferase type I (GGTase-I). The invention also provides for a method of inhibiting farnesyl-protein transferase and geranylgeranyl-protein transferase type I by administering a compound that is a dual inhibitor of both of those prenyl-protein transferases. The invention also provides for a method of identifying such a compound, the method comprising a modified inhibitory assay that incorporates a modulator anion that alters the in vitro potency of prenyl-protein transferase inhibitors in a way that predicts their potency in vivo, thus providing convenient identification of compounds that possess such in vivo activity.

Abstract: A method for determining the concentration of acid-gases in an amine-regeneration system, such as is typically found in a natural gas refining plant, having a device for measuring the pH of the system from which the concentration of the acid-gases complexed and the amine can be calculated using an empirically-derived relationship between acid-gas concentration and pH. The invention also includes a system for controlling amine regeneration based upon the above described determining method.

Abstract: The total base number of an oil sample of measured volume is determined by solvating the oil sample, adding a predetermined amount of acidic species to the solvated sample to react the acidic species with any basic species contained in the oil sample, extracting the remaining acidic species into an extractant phase, separating the extractant phase from the oil sample, and measuring the acidic species content of the extractant phase to determine the quantity of basic species in the oil sample. The same technique may be used to determine the total acid number of an oil sample by adding a predetermined amount of basic species to the sample and measuring the basic species content of the extractant phase.

Abstract: A device for measuring free acid concentrations in a solution bearing an ionic constituent therein, forms a test sample of the solution and measures the concentration of the ionic constituent in solution in the test sample. The device measures conductivity of the test sample and calculates the concentration of free acid in the test sample based on the conductivity and the concentration of the ionic constituent in solution.

Abstract: A sensor device is disclosed for identification of a gaseous component in a gaseous or liquid sample. The sensor device comprises an optode membrane having sensitivity for the gaseous component to be identified. The optode membrane incorporates two ionophores, at least one of which is a chromoionophore capable of changing absorption spectrum. The sensor device further comprises a hydrophobic gas-permeable membrane, one side of which is positioned upon the optode membrane to prevent direct contact of the optode membrane with the liquid or gaseous sample while still permitting passage of the gaseous component to be identified. As a result, ionic compounds incapable of passing through the lipophilic gas-permeable membrane do not interfere with the identification process leading to a highly sensitive sensor.

Abstract: A method and system to optimize the acid strength and level of total organic carbon (TOC) of process streams in which specific hydrocarbons are extracted from hydrocarbon mixtures by sulfuric acid.

Abstract: The total base number of an oil sample of measured volume is determined by solvating the oil sample, adding a predetermined amount of acidic species to the solvated sample to react the acidic species with any basic species contained in the oil sample, extracting the remaining acidic species into an extractant phase, separating the extractant phase from the oil sample, and measuring the acidic species content of the extractant phase to determine the quantity of basic species in the oil sample. The same technique may be used to determine the total acid number of an oil sample by adding a predetermined amount of basic species to the sample and measuring the basic species content of the extractant phase.

Abstract: A process for the rapid extraction, separation, and detection of free and total sulfites in food is disclosed. The process comprises the steps of (a) extracting sulfites from a sample in the presence of a medium having a selected pH to produce an extractant; (b) filtering the extractant; (c) subjecting the filtered extractant to anion exclusion chromatography to produce a sulfite-containing effluent; and (d) detecting the proportion of sulfites in the effluent. The process may be used either to determine free sulfites (by performing extraction in the presence of an acid medium), or to determine total sulfites (by performing extraction in the presence of an alkaline medium). The process of the present invention may be used to determine sulfite levels of 1.0 ppm or less.

Abstract: Automatic titration analysis apparatus includes a sampling mechanism, a titration mechanism, an analysis mechanism and a control mechanism. The sampling mechanism takes a prescribed quantity of a sample for analysis in accordance with a first signal. The titration mechanism titrates a prescribed quantity of a reagent for analysis of the sample and provides a titer at an end point of the titration according to second signals. The analysis mechanism receives the sample from the sampling mechanism, analyzes the sample and converts a change in the physical properties of the sample caused by the titration into an electrical quantity.

Abstract: A method and an apparatus providing a simple and speedy determination of a slight amount of sulfurous acid contained in liquids by means of pH meters, based on the Modified Rankine's method in principle, and wherein the pH of a first sample of liquid is determined before and after adding an amount of hydrogen peroxide thereto, the pH of a second sample of liquid is determined before and after adding an amount of an acid or lower pH buffer solution thereto, and the concentration of sulfurous acid in the liquid is calculated from the measured pH values and an equation derived from the functional relationship:c=f(.DELTA.pH.sub.A, .DELTA.pH.sub.B)wherein c is the concentration of sulfurous acid.