A tool having an energy source and a surface roughness measurement device is provided. A baseline measurement of surface roughness of a sample is made. The sample is then exposed to energy from the energy source, causing the temperature of the sample to increase. A second measurement of surface roughness of the sample is made. The change in surface roughness of the sample is determined. Formation properties such as the total organic carbon in the sample is inferred based on the determined change in surface roughness of the sample. The tool may be disposed in a wellbore and may use packers to isolate a portion of the wellbore, or it may use a hydraulic seal on an extendible member to isolate a sample portion of the wellbore wall. The energy source may be a laser that produces radiation that selectively heats a particular component of the sample constituent material.

Described are methods and systems using optical fiber interferometry to sense interference causing events in a region of interest and differentiate between a strain event and a thermal event. Other methods and systems relate to the use of optical fiber interferometry for determining temperature offset in a region of interest and using the determined temperature offset for determining temperature in the region of interest.

Described are methods and systems using optical fiber interferometry to sense interference causing events in a region of interest and differentiate between a strain event and a thermal event. Other methods and systems relate to the use of optical fiber interferometry for determining temperature offset in a region of interest and using the determined temperature offset for determining temperature in the region of interest.

Optical techniques for determining thermal properties of materials are described. Optical techniques include Raman scattering and thermal properties include relative length change and coefficient of thermal expansion. Correlations of features of bands observed in the Raman spectra of several glasses with thermal properties of the glasses are demonstrated. The technique provides a convenient method for determining thermal expansion properties of materials.

Optical techniques for determining thermal properties of materials are described. Optical techniques include Raman scattering and thermal properties include relative length change and coefficient of thermal expansion. Correlations of features of bands observed in the Raman spectra of several glasses with thermal properties of the glasses are demonstrated. The technique provides a convenient method for determining thermal expansion properties of materials.

Disclosed are a method and an apparatus for testing residual stress in coatings. The method includes: obtaining elastic modulus of a coating and a substrate of a target object; obtaining a temperature during the coating preparation of the target object; obtaining a cross-sectional area of the coating and a cross-sectional area of the substrate of the target object; obtaining a thermal expansion coefficient of the coating and a thermal expansion coefficient of the substrate of the target object; and calculating the coating residual stress σ.sub.c of the target object by the following formula:

[00001]${\sigma }_c=\left(\frac{S_s}{S_c}\right).Math.\left[1-\left(\frac{E_s.Math.S_s}{E_c.Math.S_c}+\frac{{\alpha }_c}{{\alpha }_s}\right).Math.\text{/}.Math.\left(1+\frac{E_s.Math.S_s}{E_c.Math.S_c}\right)\right].Math.E_s.Math.{\alpha }_s.Math.\Delta .Math..Math.T_c,$

wherein, S.sub.c is the cross-section area of the coating, S.sub.s is the cross-section area of the substrate, E.sub.c is the elastic modulus of the coating, E.sub.s is the elastic modulus of the substrate, α.sub.c is the thermal expansion coefficient of the coating, α.sub.s is the thermal expansion coefficient of the substrate, and ΔT.sub.c is the temperature during the coating preparation.

Disclosed are a method and an apparatus for testing residual stress in coatings. The method includes: obtaining elastic modulus of a coating and a substrate of a target object; obtaining a temperature during the coating preparation of the target object; obtaining a cross-sectional area of the coating and a cross-sectional area of the substrate of the target object; obtaining a thermal expansion coefficient of the coating and a thermal expansion coefficient of the substrate of the target object; and calculating the coating residual stress σ.sub.c of the target object by the following formula:

[00001]${\sigma }_c=\left(\frac{S_s}{S_c}\right).Math.\left[1-\left(\frac{E_s.Math.S_s}{E_c.Math.S_c}+\frac{{\alpha }_c}{{\alpha }_s}\right).Math.\text{/}.Math.\left(1+\frac{E_s.Math.S_s}{E_c.Math.S_c}\right)\right].Math.E_s.Math.{\alpha }_s.Math.\Delta .Math..Math.T_c,$

wherein, S.sub.c is the cross-section area of the coating, S.sub.s is the cross-section area of the substrate, E.sub.c is the elastic modulus of the coating, E.sub.s is the elastic modulus of the substrate, α.sub.c is the thermal expansion coefficient of the coating, α.sub.s is the thermal expansion coefficient of the substrate, and ΔT.sub.c is the temperature during the coating preparation.

A device for determining an expansion pressure and an expansion displacement generated by coking coal based on self-regulation of a spring includes a pyrolysis reactor, which is provided in a high temperature carbonization furnace. Two porous pressing plates are provided at both sides of a coal sample, and two metal filter plates are provided at both sides of the sample. Upper and lower openings of the reactor are sealed respectively with a connecting flange. The pressing plate above the sample is connected to a mounting baffle of a detection mechanism through a lightweight connecting rod and a spring. The detection mechanism is provided with a displacement sensor and a pressure sensor. This application further provides a detection method using the above device.

In order to determine a volume thermal expansion coefficient of a liquid, a sample of the liquid is placed inside a cell of a calorimeter followed by an incremental increase of pressure inside the cell containing the liquid. After each pressure increase heat flow into the cell and volume of the liquid are measured. Based on results of the measurements of the heat flow and accounting for initially evaluated cell volume, the volume thermal expansion of the liquid is determined.

In order to determine a volume thermal expansion coefficient of a liquid, a sample of the liquid is placed inside a cell of a calorimeter followed by an incremental increase of pressure inside the cell containing the liquid. After each pressure increase heat flow into the cell and volume of the liquid are measured. Based on results of the measurements of the heat flow and accounting for initially evaluated cell volume, the volume thermal expansion of the liquid is determined.