Abstract: Methods and sensors for the detection, identification, and quantification of one or more gas species, including volatile organic compounds, in a test sample are described. Methods employ gas sensors comprising a diffusion matrix present on the sensor surface. A gas analyte in a test sample diffuses through the matrix and is detected upon interaction of the analyte with the sensor. A response profile of a gas sensor to a gas analyte in the test sample is compared to a control gas sensor response profile determined in a similar manner for a known gas species. Comparisons of test sample and control sample sensor response profiles enable detection, identification, and quantification of a gas species analyte in a test sample.

Abstract: An apparatus comprises a housing defining a chamber that has a liquid disposed therein, and a sensor submerged in the liquid. The sensor comprises a porous conductive film on a substrate, and the film comprises chemiresistive semiconducting metal oxide structures. The sensor also comprises an electrode pair operably connected to the porous conductive film for generating electric current in the film and for detecting a change in an electrical property of the film. The apparatus can be used to detect, identify, and quantify ions and molecules in a liquid sample. Molecules and ions, in a liquid sample, that interact with the porous conductive film can cause a change in an electrical property of the film. The change in electrical property of the film can be correlated with the presence and amount of the molecules or ions.

Abstract: Catalyst particles and methods for making same are disclosed herein. The catalyst particles can include a ceramic support containing silica and alumina. The ceramic support can have a macropore concentration of about 15% to about 45%, a mesopore concentration of about 20% to 50%, and a micropore concentration of about 8% to about 30% based on the total pore volume of the ceramic support. The ceramic support can also have a surface area of about 0.5 m2/g to about 50 m2/g. The catalyst particles can have a long term permeability at 7,500 psi of at least about 10 D in accordance with ISO 13503-5.

Abstract: An apparatus comprises a housing defining a chamber that has a liquid disposed therein, and a sensor submerged in the liquid. The sensor comprises a porous conductive film on a substrate, and the film comprises chemiresistive semiconducting metal oxide structures. The sensor also comprises an electrode pair operably connected to the porous conductive film for generating electric current in the film and for detecting a change in an electrical property of the film. The apparatus can be used to detect, identify, and quantify ions and molecules in a liquid sample. Molecules and ions, in a liquid sample, that interact with the porous conductive film can cause a change in an electrical property of the film. The change in electrical property of the film can be correlated with the presence and amount of the molecules or ions.

Abstract: An apparatus comprises a housing defining a chamber that has a liquid disposed therein, and a sensor submerged in the liquid. The sensor comprises a porous conductive film on a substrate, and the film comprises chemiresistive semiconducting metal oxide structures. The sensor also comprises an electrode pair operably connected to the porous conductive film for generating electric current in the film and for detecting a change in an electrical property of the film. The apparatus can be used to detect, identify, and quantify ions and molecules in a liquid sample. Molecules and ions, in a liquid sample, that interact with the porous conductive film can cause a change in an electrical property of the film. The change in electrical property of the film can be correlated with the presence and amount of the molecules or ions.

Abstract: Catalyst particles and methods for making same are disclosed herein. The catalyst particles can include a ceramic support containing silica and alumina. The ceramic support can have a macropore concentration of about 15% to about 45%, a mesopore concentration of about 20% to 50%, and a micropore concentration of about 8% to about 30% based on the total pore volume of the ceramic support. The ceramic support can also have a surface area of about 0.5 m2/g to about 50 m2/g. The catalyst particles can have a long term permeability at 7,500 psi of at least about 10 D in accordance with ISO 13503-5.

Abstract: A catalytic proppant and methods for making and using same are disclosed herein. The catalytic proppant can include a proppant support containing silica and alumina. The proppant support can have a macropore concentration of about 15% to about 45%, a mesopore concentration of about 20% to 50%, and a micropore concentration of about 8% to about 30% based on the total pore volume of the proppant support. The proppant support can also have a surface area of about 0.5 m2/g to about 50 m2/g. The catalytic proppant can have a long term permeability at 7,500 psi of at least about 10 D in accordance with ISO 13503-5.

Abstract: Techniques for multiuser application platform are described. Generally, a multiuser application allow interaction by multiple different users with a single executing instance of the application. Implementations include a multiuser operating system and a multiuser application programming interface that enable interaction by multiple users with an executing instance of a multiuser application.

Abstract: Analyte filter arrays and methods for making an analyte filter array are provided. The arrays are formed using a dispersion of filter particles having selected moieties attached to the surface of the particles and a microarray having complementary moieties formed in an array on a substrate, such that each filter particle is attached to a selected region of the microarray. The moiety on the substrate may be RNA or DNA or other molecule. The substrate may be a surface of a detector array, a membrane that may be placed in registration with the detector array or a stamp used to transfer the filter array to a detector array.

Abstract: An apparatus comprises a housing defining a chamber that has a liquid disposed therein, and a sensor submerged in the liquid. The sensor comprises a porous conductive film on a substrate, and the film comprises chemiresistive semiconducting metal oxide structures. The sensor also comprises an electrode pair operably connected to the porous conductive film for generating electric current in the film and for detecting a change in an electrical property of the film. The apparatus can be used to detect, identify, and quantify ions and molecules in a liquid sample. Molecules and ions, in a liquid sample, that interact with the porous conductive film can cause a change in an electrical property of the film. The change in electrical property of the film can be correlated with the presence and amount of the molecules or ions.

Abstract: Methods for manufacturing electrically-conductive proppant particles are disclosed. The methods can include preparing a slurry containing water, a binder, and a raw material having an alumina content, atomizing the slurry into droplets, and coating seeds containing alumina with the droplets to form a plurality of green pellets. The green pellets can be contacted with an activation solution containing at least one catalytically active material to provide activated green pellets including the at least one catalytically active material. The method can include sintering the activated green pellets to provide a plurality of proppant particles. The plurality of proppant particles can be contacted with a plating solution containing one or more electrically-conductive material to provide electrically-conductive proppant particles.

Abstract: Methods and sensors for detection and quantification of one or more analyte in a test sample are described. A response profile of a gas sensor to a control sample of a known interrogator gas is determined. The gas sensor is exposed to a test sample then to a second sample comprising the known interrogator gas, and a test sample response profile of the gas sensor is determined. One or more test sample sensor response profiles are compared with one or more control sensor response profiles for detecting, identifying, and quantifying one or more analytes in the test sample.

Abstract: Methods and sensors for detection and quantification of one or more analyte in a test sample are described. A response profile of an ion sensor to a control sample of a known interrogator ion is determined. The ion sensor is exposed to a test sample then to a second sample comprising the known interrogator ion, and a test sample response profile of the ion sensor is determined. One or more test sample sensor response profiles are compared with one or more control sensor response profiles for detecting, identifying, and quantifying one or more analytes in the test sample.

Abstract: Methods and systems for determining subterranean fracture closure are disclosed herein. The methods can include electrically energizing a casing of a wellbore that extends from a surface of the earth into a subterranean formation having a fracture that is at least partially filled with an electrically conductive proppant and measuring a first electric field response at the surface or in an adjacent wellbore at a first time interval to provide a first field measurement. The methods can also include measuring a second electric field response at the surface or in the adjacent wellbore at a second time interval to provide a second field measurement and determining an increase in closure pressure on the electrically conductive proppant from a difference between the first and second field measurements.

Abstract: Electrically conductive proppant particles having electrically conductive coatings are disclosed. The electrically conductive proppant particles can include a proppant particle having less than about 30% crush at 4,000 psi and a specific gravity of about 4 g/cm3 or less and a coating of an adhesive material or optionally an initial layer of nickel formed on an outer surface of the proppant particle. An electrically conductive material deposited on an outer surface of the adhesive material or the initial layer of nickel. Methods for making and using such electrically conductive proppant particles having electrically conductive coatings are also disclosed.

Abstract: Methods for manufacturing electrically-conductive proppant particles are disclosed. The methods can include preparing a slurry containing water, a binder, and a raw material having an alumina content, atomizing the slurry into droplets, and coating seeds containing alumina with the droplets to form a plurality of green pellets. The green pellets can be contacted with an activation solution containing at least one catalytically active material to provide activated green pellets including the at least one catalytically active material. The method can include sintering the activated green pellets to provide a plurality of proppant particles. The plurality of proppant particles can be contacted with a plating solution containing one or more electrically-conductive material to provide electrically-conductive proppant particles.

Abstract: Electrically-conductive sintered, substantially round and spherical particles and methods for producing such electrically-conductive sintered, substantially round and spherical particles from an alumina-containing raw material. Methods for using such electrically-conductive sintered, substantially round and spherical particles in hydraulic fracturing operations.

Abstract: Methods and systems for determining subterranean fracture closure are disclosed herein. The methods can include electrically energizing a casing of a wellbore that extends from a surface of the earth into a subterranean formation having a fracture that is at least partially filled with an electrically conductive proppant and measuring a first electric field response at the surface or in an adjacent wellbore at a first time interval to provide a first field measurement. The methods can also include measuring a second electric field response at the surface or in the adjacent wellbore at a second time interval to provide a second field measurement and determining an increase in closure pressure on the electrically conductive proppant from a difference between the first and second field measurements.

Abstract: Electrically-conductive sintered, substantially round and spherical particles and methods for producing such electrically-conductive sintered, substantially round and spherical particles from an alumina-containing raw material. Methods for using such electrically-conductive sintered, substantially round and spherical particles in hydraulic fracturing operations.

Abstract: A catalytic proppant and methods for making and using same are disclosed herein. The catalytic proppant can include a proppant support containing silica and alumina. The proppant support can have a macropore concentration of about 15% to about 45%, a mesopore concentration of about 20% to 50%, and a micropore concentration of about 8% to about 30% based on the total pore volume of the proppant support. The proppant support can also have a surface area of about 0.5 m2/g to about 50 m2/g. The catalytic proppant can have a long term permeability at 7,500 psi of at least about 10 D in accordance with ISO 13503-5.