Raman Natural Gas Analyzer: Effects of Composition on Measurement Precision.

Raman spectroscopy is a promising method for analyzing natural gas due to its high measurement speed and the potential to monitor all molecular components simultaneously. This paper discusses the features of measurements of samples whose composition varies over a wide range (0.005-100%).

[Damage of the knee posterior cruciate ligament: biomechanics, basic diagnostics, treatment and secondary osteoarthritis prevention directions].

The analysis of literature data was performed on the pathogenesis, diagnosis and treatment of injuries of the posterior cruciate ligament (PCL) of the knee joint. PCL is the largest intra-articular ligament of the knee joint, can withstand the maximum loads compared with other ligaments. It was noted that, in general, in cases of damage to the PCL, it is necessary to use a set of diagnostic methods, and the basic principles for the choice of optimal treatment plan for this patient.

Application of Raman Spectroscopy for Determination of Syngas Composition.

Raman spectroscopy is a unique tool for fast analysis of multicomponent gas media. In this work, we studied the features of application of this method for monitoring the syngas (mixture of CO + H + CH + CO + N) composition. To determine concentrations, we used contour fit method, where the Raman spectrum of mixture is compared with a synthetically calculated spectrum.

Effects of pressure and composition on Raman spectra of CO-H-CO-CH mixtures.

There is great interest in the development of renewable and environmentally friendly fuel sources such as biogas and syngas for generation of heat and electricity. Raman spectroscopy is a promising method for rapid quantitative analysis of the composition of such gases. To improve the accuracy of the method, information is needed on changes in the spectra of the main components as a function of pressure and gas composition.

Enhancement of Raman scattering of a gaseous medium near the surface of a silver holographic grating.

The Letter demonstrates a possibility to enhance the Raman scattering of a gaseous medium due to an enhanced electromagnetic field caused by the excitation of propagating surface plasmon polaritons (PSPPs) on a silver holographic grating. Efficiency of collinear and noncollinear schemes of PSPP excitation on a metal-gaseous medium interface was studied. When using a collinear scheme, we registered an eightfold enhancement of the Raman scattering of atmospheric nitrogen and oxygen, where the average gain near the PSPP-active surface was ∼4×10.