68 results about "X-ray absorption spectroscopy" patented technology

Systems and methods for chip-integrated label-free detection and absorption spectroscopy with high throughput, sensitivity, and specificity are disclosed. The invention comprises packaged chips for multiplexing photonic crystal waveguide and photonic crystal slot waveguide devices. Other embodiments are described and claimed.

The present invention relates to a test chamber that can be used to perform a variety of X-ray and neutron spectroscopy experiments including powder diffraction, small-angle scattering, X-ray absorption spectroscopy, and pair distribution functions, such chamber comprising a first electrode with an X-ray transparent window; a second electrode with an X-ray transparent window; a plurality of insulating gaskets providing a hermetic seal around the sample and preventing contact between said first and second electrodes; and an insulating housing into which the first electrode is secured.

This disclosure presents systems for x-ray absorption fine structure (XAFS) measurements that have x-ray flux and flux density several orders of magnitude greater than existing compact systems. These are useful for laboratory or field applications of x-ray absorption near-edge spectroscopy (XANES) or extended x-ray fine absorption structure (EXFAS) spectroscopy.The higher brightness is achieved by using designs for x-ray targets that comprise a number of aligned microstructures of x-ray generating materials fabricated in close thermal contact with a substrate having high thermal conductivity. This allows for bombardment with higher electron density and / or higher energy electrons, leading to greater x-ray brightness and high flux.The high brightness x-ray source is then coupled to an x-ray reflecting optical system to collimate the x-rays, and a monochromator, which selects the exposure energy. Absorption spectra of samples using the high flux monochromatic x-rays can be made using standard detection techniques.

Systems and methods for chip-integrated label-free detection and absorption spectroscopy with high throughput, sensitivity, and specificity are disclosed. The invention comprises packaged chips for multiplexing photonic crystal microcavity waveguide and photonic crystal slot waveguide devices. The packaged chips comprise crossing waveguides to prevent leakage of fluids from the microfluidic channels from the trenches or voids around the light guiding waveguides. Other embodiments are described and claimed.

Apparatus and methods for rapidly detecting, localizing, imaging, and quantifying leaks of natural gas and other hydrocarbon and greenhouse gases. Scanning sensors, scan patterns, and data processing algorithms enable monitoring a site to rapidly detect, localize, image, and quantify amounts and rates of hydrocarbon leaks. Multispectral short-wave infrared detectors sense non-thermal infrared radiation from natural solar or artificial illumination sources by differential absorption spectroscopy. A multispectral sensor is scanned to envelop an area of interest, detect the presence and location of a leak, and raster scan the area around the leak to create an image of the leak. The resulting absorption image related to differential spectral optical depth is color mapped to render the degree of gas absorption across the scene. Analysis of this optical depth image, with factors including known inline pressures and / or surface wind speed measurements, enable estimation of the leak rate, i.e., emission mass flux of gas.

Methods are disclosed utilizing synchrotron X-ray microscopy including x-ray fluorescence and x-ray absorption spectra to probe elemental distribution and elemental speciation within a material, and particularly a solid that may have one or more elements distributed on a solid substrate. Representative materials are relatively homogeneous in composition on the macroscale but relatively heterogeneous on the microscale. The analysis of such materials, particularly on a macroscale at which their heterogeneous nature can be observed, provides valuable insights into the relationships or correlations between localized concentrations of elements and / or their species, and concentrations of other components of the materials. Sample preparation methods, involving the use of a reinforcing agent, which are advantageously used in such methods are also disclosed.

A method and system for measuring heat energy of a combustible fluid in which light having wavelengths in the near-infrared is directed into a test cell containing the combustible fluid and portions of the light not absorbed by the combustible fluid and passing out of the cell are spatially dispersed by wavelength, forming a light spectrum that is projected onto a detector. The light spectrum is digitized and inputted into a data processing unit in which it is compared to the actual spectrum of the light source stored in the system to determine the absorbance spectrum of the combustible fluid. The system is spectrally calibrated by identifying known spectral features of the combustible gas absorbance spectrum. To correct for deviations in the original light source spectrum, a light source calibration system is employed. Upon determination of the absorbance spectrum of the combustible fluid, the heating value of the combustible fluid is determined by comparing the absorbance spectrum to a plurality of spectra located within an on-board database.

A method and device for measuring a concentration of a preselected gas in a gas sample are disclosed. The device comprises a Herripott type multipass cell having a center axle and a housing surrounding and spaced from the axle to provide a tubular sample cavity. The gas sample is pumped through the sample cavity via apertures provided in opposed ends of the axle. A first mirror and a second mirror are supported at opposed ends of the axle. A light source, e.g. a laser or LED, is provided for emitting a light beam into the sample cavity via en entry aperture in the first mirror, the light beam having a wave length at which the preselected gas strongly absorbs. The beam is reflected between the mirrors for a number of times before exiting the cell via an exit aperture in the second mirror and impinging the intensity of the unattenuated light beam and a detector for detecting the intensity of light transmitted through the second mirror after a single pass through the cell. The light source is operatively connected to a heat control assembly having a heat sink and the gas sample is passed said heat sink to augment temperature control of the light source.

A method for performing x-ray absorption spectroscopy and an x-ray absorption spectrometer system to be used with a compact laboratory x-ray source to measure x-ray absorption of the element of interest in an object with both high spatial and high spectral resolution. The spectrometer system comprises a compact high brightness laboratory x-ray source, an optical train to focus the x-rays through an object to be examined, and a spectrometer comprising a single crystal analyzer (and, in some embodiments, also a mosaic crystal) to disperse the transmitted beam onto a spatially resolving x-ray detector. The high brightness / high flux x-ray source may have a take-off angle between 0 and 105 mrad. and be coupled to an optical train that collects and focuses the high flux x-rays to spots less than 500 micrometers, leading to high flux density. The coatings of the optical train may also act as a “low-pass” filter, allowing a predetermined bandwidth of x-rays to be observed at one time while excluding the higher harmonics.

A system and method to discriminate between a first preselected gas and at least one other preselected gas use of an absorption spectroscopy analyzer that includes a Herriott cell and a temperature sensitive light source. The light source operates at a temperature that emits a beam at a wavelength that corresponds to high absorption by a first preselected gas. When a predetermined level of this gas is detected in a gas sample, the analyzer changes the operating temperature of the light source to emit a beam at a wavelength that corresponds to high absorption by a second preselected gas. The second preselected gas can be a different isotope of the first preselected gas.

Process and measuring equipment for improving the signal resolution in gas absorption spectroscopy, wherein the measuring equipment includes a laser light source, a light detector and a measuring chamber arranged in between, and furthermore a light source control unit and a light detector evaluation unit. To improve the signal resolution, the noise intensity of the measuring equipment is reduced by averaging over time the interfering signal portions caused by back-reflections, etalons respectively self-mixing effects. This is accomplished by a light modulator arranged downstream the laser light source that continuously periodically influences the optical path length of the light beam. Thereto the light modulator includes an optical element with an adjustable refractory index that continuously cyclically alters the phase of the laser light of the light beam.

The invention provides a mercury vapor continuous monitoring device and monitoring method based on diode laser, belonging to the technical field of mercury vapor monitoring. The invention enables the problems that a conventional mercury vapor measuring system has a complex structure and real-time monitoring of mercury emission in conventional mercury vapor measuring is poor to be overcome. The monitoring device comprises a signal generator, a first laser diode controller, a second laser diode controller, a first laser diode, a second laser diode, a first reflector, a dichroic beam combiner, afirst convex lens, BBO crystals, a second convex lens, a beam splitter prism, a second reflector, a spectroscope, a sample cell, a reference cell, a first optical filter, a second optical filter, a first detector, a second detector and a data acquisition analyzer. According to the monitoring method, diode laser absorption spectroscopy is used to realize continuous monitoring of the concentration of mercury vapor, and spectral information of reference gas is utilized to realize selective identification and quantitative detection of gaseous elemental mercury, thereby eliminating interference brought by gas like sulfur dioxide and nitrogen dioxide. The monitoring device and the monitoring method provided in the invention are used for on-line monitoring of mercury vapor.

The invention relates to a gas concentration monitoring device by combining integrating sphere and diode laser absorption spectroscopy and a monitoring method based on the monitoring device, and relates to the gas concentration monitoring device and the monitoring method based on the monitoring device, and the invention solves the problem of low sensitivity and poor miniaturization degree of the current gas concentration monitoring devices. According to the invention, a diode laser is employed as light source, the output light is passed through a collimating lens and then enters into an integrating sphere through a light entering hole of the integrating sphere, the integrating sphere is filled with gas to be measured with unknown, the laser is interacted with gas, an uniform light field is obtained by multiple uniform scattering in the integrating sphere, the scattered light enables emergence through a light outputting hole of the integrating sphere, the emergent light signals are focused to a light reception surface of a detector by a focusing lens, and transformed to electric signals and collected by a data collection card, and the data is input to a computer through a PCI interface for processing to obtain the gas concentration to be measured. The invention is suitable for monitoring the gas concentration.

A method of characterizing conditions in a tissue, by (a) providing a catheter that has a light source that emits light in selected wavenumbers within the range of mid-IR spectrum; (b) directing the light from the catheter to an area of tissue at a location inside a blood vessel of a subject; (c) collecting light reflected from the location and generating a reflectance spectra; and (d) comparing the reflectance spectra to a reference spectra of normal tissue, whereby a location having an increased number of absorbance peaks at said selected wavenumbers indicates a tissue inside the blood vessel containing a physiological marker for atherosclerosis.

An absorption spectroscopy apparatus provides an apparatus for analyzing gaseous sample. A measuring section irradiates the gaseous sample with terahertz radiation. An analysis section calculates a concentration of a specific constituent based on a level of absorbance by the gaseous sample. Terahertz radiation at least contains frequency components where the specific constituent shows an absorbance larger than an absorbance by a background constituent. Terahertz radiation at least contains frequency components where a spectrum of absorbance by the background constituent shows relatively flat profile.

The present invention provides a system for measuring concentrations of trace gases in gas mixtures using the absorption spectroscopy method. The system comprising: a resonant optical cavity, a continuous-wave stepwise tunable external cavity laser having a DFB laser as a gain media; a detector system for measuring an absorption of laser light by the gas in the resonant optical cavity, wherein the roundtrip optical cavity length of the external cavity laser are the roundtrip optical cavity length of the resonant cavity are close

The invention discloses an FENO detection system based on broadband light source cavity enhanced absorption spectroscopy, which belongs to the field of medical apparatuses and instruments. Specifically speaking, the FENO detection system is a nitric oxide detection system employing combination of an LED broadband light source and cavity enhanced absorption spectroscopy. The system mainly comprises a light source part, an FENO concentration detection part and an NO absorption signal analysis part, wherein an LED light emitting diode is used as a light source, the FENO concentration detection part comprises an optical resonant cavity composed of two collimating lenses, two convex lenses and two concave spherical surface high reflectivity mirrors, an air inlet, two air washing and exhausting ports, etc., and the NO absorption signal analysis part is composed of a spectrometer, a data acquisition and processing system and a display. The FENO detection system has the following advantages: through usage of combined and broadband light source cavity enhanced absorption spectroscopy, detection sensitivity is effectively improved, real-time detection is realized, a detection limit reaches ppm magnitude, good specificity is obtained, no pollution is produced, and application demands of medical detection are effectively met.

A method of processing raw measurement data from a tunable diode laser absorption spectroscopy (TDLAS) tool or other spectroscopic instrument is provided that determines what types of noise (electronic or process flow) are present in the measurement. Based on that determination, the noise is reduced by performing a weighted averaging using weights selected according to the dominant type of noise present, or a general case is applied to determine weights where neither noise type is dominant. The method also involves performing continuous spectroscopy measurements with the tool, with the data and weighted averaging being constantly updated. Weighting coefficients may also be adjusted based on similarity or difference between time-adjacent traces.

The invention provides a method for colorimetric-fluorescent two-channel detection of alkaline phosphatase activities. The method comprises the following steps: catalyzing a substrate trisodium L-ascorbyl-2-phosphate (AAP) of alkaline phosphatase by utilizing the alkaline phosphatase so as to hydrolyze to generate ascorbic acid (AA) with reducibility, whereas the AA can cause a Tollens reagent tobe reduced to an Ag elementary substance; under the condition that gold nanoparticles (AuNPs) and graphene quantum dots (GQDs) exist, Ag can be deposited on the surface of AuNPs to form gold and silver core shell nanoparticles (Au@AgNPs) and quenches the fluorescence of GQDs. According to the method, metallization of enzymatic silver ions, AuNPs-induced silver deposition and Au@AgNPs-quenched GQDsfluorescence are combined, the changes of color, ultraviolet-visible absorption spectroscopy and fluorescence intensity are utilized, and the colorimetric-fluorescent two-channel detection of the alkaline phosphatase activities can be realized. The method has the characterics that the sensitivity is high, the specificity is strong, the response is fast, the operation is simple, and no complex instruments are required.

The present invention relates to a method for the preparation of a sample for microstructure diagnostics, in particular for transmission electron microscopy TEM, scanning electron microscopy or X-ray absorption spectroscopy, wherein a flat, preferably plane-parallel plate is irradiated along each of the two opposite surfaces thereof with a high-energy beam such that, as a result of radiation-induced material removal, there is formed in each of said two surfaces a depression which runs preferably parallel to a central plate plane, wherein said two depressions are formed, so as to run at both sides of said / a central plate plane, such that the longitudinal axes thereof, as viewed in a projection of said longitudinal axes onto said central plate plane, intersect at a predefined angle a > 0 DEG , preferably a = 10 DEG , preferably a = 20 DEG , preferably a = 30 DEG , and that, in the region of intersection of the two depressions, a material portion which is preferably transparent to electron beams and which is of predefined minimum thickness as viewed perpendicular to said central plate plane remains between said depressions as a sample. The invention also relates to a correspondingly designed device.

The invention relates to a fitting method for extracting a direct absorption line in the TDLAS technology. On the basis of the Beer-Lambert law, an expression function of a gas absorption line under the direct absorption spectroscopy is deduced; partial data of an actually measuring signal are selected by using the function as an objective function of a nonlinear fitting algorithm; an optimized undetermined coefficient of the objective function is obtained based on calculation of the algorithm; and a complete gas absorption line is restored. According to the invention, the complete absorptionline is restored based on a few of data points; a problem of large error of the gas concentration calculation results of different carrier gas under the same concentration is solved; and the detectionprecision and accuracy are improved.

The invention discloses a method for obtaining a high-quality X-ray absorption spectrum of a thin film sample. In a measuring process of the thin film sample, after diffraction spots are generated by exposing a single-crystal substrate of the thin film sample through a dry film, exposure points are shielded by a lead sheet to prevent diffraction signals caused by the substrate from entering a detector so as to obtain the high-quality X-ray absorption spectrum of the thin film sample. The dry film consists of carbon, nitrogen, oxygen and a trace element lithium, has an effective atomic number within 6-8 and the film thickness of about 100-200 microns, does not cause a serious background to the hard X-ray absorption spectrum, and particularly can be integrated with a light filter in the detector to filter out a scattering effect caused by incident light and a diffraction effect caused by the substrate of the thin film sample. Therefore, a simple and effective way for obtaining the high-quality X-ray absorption spectrum of the thin film sample is provided.