The present invention provides a method for the rapid monitoring of biological analytes in a point-of-care setting by providing a smart phone; providing a sample chamber; providing a sample; providing a dark box with a smartphone holder attached to the dark box top with the camera opening positioned about the aperture, adding a biological specimen suspected of containing a biological analyte in the sample chamber; adding a bis(2,4,6-trichlorophenyl) oxalate, an imidazole and a fluorophore to the sample chamber to react with the biological analyte; placing the sample chamber into the dark box; generating an emission from the fluorophore in response to the reaction with the biological analyte; and recording a set of time-lapse images of the emission with the smartphone.

A round bar tensile test specimen for a sulfide stress corrosion cracking test of a steel, the specimen including a parallel section, a shoulder section, and a grip section. A sectional shape of the shoulder section being formed by a curve having two or more radii of curvature. A radius of curvature R1 (mm) of a portion of the curve adjacent to the parallel section being 15 mm or more, and the radius of curvature R1 (mm) satisfying (0.22119)R1100 in terms of load stress (MPa) of the sulfide stress corrosion cracking test. A length X1 (mm) of the portion of the curve having the radius of curvature R1 in a longitudinal direction of the test specimen satisfying X1{(r/8)(R1r.sup.2/4)}. Additionally, other radii of curvature of the curve being smaller than the radius of curvature R1.

Processes for sensing a variety of toxic chemicals and/or processes for determining the residual life of a filter or filtration system are provided. Exemplary process for sensing a toxic chemical include contacting a toxic chemical, or byproduct thereof, with a sorbent that includes a porous metal hydroxide and a transition metal reactant suitable to react with a toxic chemical or byproduct thereof. The sorbent is contacted with the toxic chemical or byproduct thereof for a sampling time. A difference between a post-exposure colorimetric state of the sorbent and a pre-exposure colorimetric state of the sorbent or control is determined to thereby sense exposure to, or the presence of, the toxic chemical or byproduct thereof.

The present invention provides a method for the rapid monitoring of biological analytes in a point-of-care setting by providing a smart phone; providing a sample chamber; providing a sample; providing a dark box with a smartphone holder attached to the dark box top with the camera opening positioned about the aperture, adding a biological specimen suspected of containing a biological analyte in the sample chamber; adding a bis(2,4,6-trichlorophenyl) oxalate, an imidazole and a fluorophore to the sample chamber to react with the biological analyte; placing the sample chamber into the dark box; generating an emission from the fluorophore in response to the reaction with the biological analyte; and recording a set of time-lapse images of the emission with the smartphone.

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.

Provided herein is technology relating to detecting gaseous analytes and particularly, but not exclusively, to devices and methods related to detecting gaseous analytes by monitoring changes in liquid crystals upon exposure to the gaseous analytes.

A method of detecting at least one of an analyte or a condition of a fluid within a subterranean formation comprises operably coupling a radiation source to at least one optical fiber coupled to a sensor comprising 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. Additional methods of determining a concentration of hydrogen sulfide in a fluid within a subterranean formation and related downhole optical sensor assemblies are disclosed.

Method for the detection and quantification of the H.sub.2S which measures concentration of the H.sub.2S in the drilling mud including the steps of measurement of the initial concentrations of H.sub.2S in free form and of the hydrogen sulphide HS.sup. and sulphide S.sup.2 ion species, dissolved in the sample of mud; acidification of the sample of mud, to generate gaseous H.sub.2S, making the hydrogen sulphide (HS.sup.) and sulphide (S.sup.2) ions dissolved in the mud and the H.sub.2S precipitated in solid form in the scavengers react; measuring concentration of the gaseous H.sub.2S formed following the first acidification; and relative system including at least: a mud sample collector; a unit measuring concentration of the hydrogen sulphide HS.sup. and sulphide S.sup.2 ion species in the sample; a unit for measuring concentration of the free H.sub.2S; a unit to acidify the sample of mud; electronic controller and storage and processing of the measurements made.

A round bar tensile test specimen for a sulfide stress corrosion cracking test of a steel, the specimen including a parallel section, a shoulder section, and a grip section. A sectional shape of the shoulder section being formed by a curve having two or more radii of curvature. A radius of curvature R1 (mm) of a portion of the curve adjacent to the parallel section being 15 mm or more, and the radius of curvature R1 (mm) satisfying (0.22119)R1100 in terms of load stress (MPa) of the sulfide stress corrosion cracking test. A length X1 (mm) of the portion of the curve having the radius of curvature R1 in a longitudinal direction of the test specimen satisfying X1{(r/8)(R1r.sup.2/4)}. Additionally, other radii of curvature of the curve being smaller than the radius of curvature R1.

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.