Abstract: A method of detecting an analyte includes vaporizing at least a portion of a fluid within a wellbore, passing the vaporized fluid adjacent a chemiresistive sensing element coupled to a drill string within the wellbore and sensing a resistivity of the chemiresistive sensing element. A sensor for detecting an analyte includes an expansion device for vaporizing a portion of a fluid within a wellbore, a chemiresistive sensing element configured to contact the vaporized fluid within the wellbore and a controller configured to pass a current through the chemiresistive sensing element and calculate a resistance of the chemiresistive sensing element in contact with the gaseous portion of the fluid. An earth-boring tool may include a bit body coupled to a drill string and the sensor.

Abstract: Sensing systems include a tube defining a Fabry-Perot cavity and an optical fiber including a distal end disposed within the Fabry-Perot cavity and a proximal end. A corrodible material caps the Fabry-Perot cavity. Devices for sensing corrosion of downhole equipment include an optical fiber with a corrodible material disposed over a distal end of the optical fiber. Systems for sensing a condition in equipment include an optical fiber with a fiber Bragg grating proximate a distal end thereof and a mass of sensor material coupled to the distal end of the optical fiber. The mass of sensor material is suspended from above the fiber Bragg grating. Other systems for sensing a condition in a wellbore include an optical fiber and a plurality of fiber Bragg gratings along a length thereof. A plurality of sensor materials are coupled to the optical fiber and surround respective fiber Bragg gratings.

Abstract: A system for determining at least one property of at least one fluid in at least one subterranean formation comprises a fluid delivery system configured and positioned to deliver a fluid into at least one of at least one subterranean formation and a wellbore extending through the at least one subterranean formation. The system comprises a radiation source within the wellbore, the radiation source configured to generate excitation radiation, carbon quantum dots disposed in the fluid, and a detector within the wellbore, the detector configured to measure at least one fluorescence property of the carbon quantum dots. Related methods of determining a property of a wellbore and methods of forming the carbon quantum dots are also disclosed.

Abstract: A system and method to isolate a portion of a wellbore and to detect fluid production from the wellbore. The system includes first and second isolators connected to a tubing string. The isolators include memory shape elements positioned between sealing elements and mandrels that may be actuated from a first shape to a second shape to create a seal within the wellbore with the sealing elements. The system may include a sensor configured to detect production from the wellbore. A sensor may be configured to detect a pressure of the isolated portion of the wellbore. A port between the isolators may permit fluid communication to the portion of the wellbore isolated by the sealing elements.

Abstract: In a composition including a plurality of coated diamond nanoparticles, each diamond nanoparticle may have at least one silane functional group covalently bonded to a surface thereof. A method of forming coated diamond nanoparticles may include functionalizing surfaces of diamond nanoparticles with at least one of a fluorine-containing compound and an oxidant; dispersing the functionalized diamond nanoparticles in a solvent comprising a silane functional group; and forming covalent bonds between the silane functional group and the diamond nanoparticles. A method of forming a diamond coating may include depositing the diamond nanoparticles over a substrate.

Abstract: A method of coating a substrate includes dispersing functionalized diamond nanoparticles in a fluid comprising metal ions to form a deposition composition; disposing a portion of the deposition composition over at least a portion of a substrate; and electrochemically depositing a coating over the substrate. The coating comprises the diamond nanoparticles and a metal formed by reduction of the metal ions in the deposition composition.

Abstract: Sensing systems include a tube defining a Fabry-Perot cavity and an optical fiber including a distal end disposed within the Fabry-Perot cavity and a proximal end. A corrodible material caps the Fabry-Perot cavity. Devices for sensing corrosion of downhole equipment include an optical fiber with a corrodible material disposed over a distal end of the optical fiber. Systems for sensing a condition in equipment include an optical fiber with a fiber Bragg grating proximate a distal end thereof and a mass of sensor material coupled to the distal end of the optical fiber. The mass of sensor material is suspended from above the fiber Bragg grating. Other systems for sensing a condition in a wellbore include an optical fiber and a plurality of fiber Bragg gratings along a length thereof. A plurality of sensor materials are coupled to the optical fiber and surround respective fiber Bragg gratings.

Abstract: Devices and methods for detecting chemicals are disclosed. A device configured for use in a wellbore includes a sensor including a quantum tunneling composite (QTC) material configured to exhibit a change in electrical resistance responsive to the sensor contacting a target chemical. The sensor includes electrical resistance measuring circuitry operably coupled to the QTC material and configured to measure the electrical resistance of the QTC material and output a sensor signal indicating the electrical resistance. A method comprises deploying the sensor into the wellbore, measuring the electrical resistance of the QTC material, and determining the presence of the target chemical responsive to detecting changes in the electrical resistance of the QTC material. Another method includes selecting at least one of the QTC material and an active material to interact with a target wellbore chemical to change the electrical resistance of the QTC material.

Abstract: A method of reducing the presence of particles in a downhole environment, comprising contacting sediment particles contained in a downhole environment, with a composition comprising: a metallic composition, an inorganic oxide-based polymer, and a solvent; the contacting occurring in the presence of a fluid capable of decomposing the metallic composition

Abstract: A coating process to infill high aspect-ratio vias and trenches in semiconductor substrates with dense boron for the production of neutron detectors and other devices uses a vacuum cathodic arc or other source of fully ionized boron plasma. Biasing of the substrate is used to impart energies to the plasma ions directing them toward the substrate, while repulsing the electrons. The full ionization produced by the source allows control of the energies of the boron ions by means of the bias voltage. The bias is alternated between coating deposition at low ion energies and sputtering of already coated material by energetic ions. Most of the sputtered material comes off the substrate top surface and between the trenches or vias and much of it is redeposited, thereby contributing to the infill. The process is suitable for carbon, boron or similar light elements, and is of particular interest for 10B, an element having exceptionally high thermal neutron cross-section.

Abstract: Neuroelectronic devices are disclosed which use charge-coupled detector array devices to stimulate, monitor and record neural network activity and response. The method and apparatus described herein uses vacuum-arc-plasma based methods of surface modification as a tool for forming large patterned neuronal arrays on substrates. The basic device features a charge coupled detector device array (CCD) having a thin protective film over the CCD, a thin patterned film to promote neuron growth, and an insulator. Methods for stimulating and monitoring stimulated and spontaneous electrical activity in individual neurons of the array can be carried out by the apparatus described.