Means for Increasing the Sensitivity of Acoustic Probing when Studying the Structure of Metals

As exemplified by the use of different approaches to processing the results of probing metals with elastic waves, means have been studied for increasing the sensitivity of the ultrasonic method. Representing processes that determine the effect that a medium has on the parameters of an elastic wave by a statistical model in the form of a Dirichlet distribution makes it possible to numerically characterize changes in the structure of a probing pulse and to improve the understanding of phenomena that occur when an elastic wave interacts with a medium, with the degree of material damage taken into account.     

Simulation of the Spatial Distribution of the Local Quantum Efficiency and Photoelectric Characteristics of Photodiode-Based Infrared Focal Plane Arrays

The results of calculation of the spatial distribution of the local quantum efficiency over the area of photodiode-based IR focal plane arrays (IR FPA) are presented. The diffusion of photogenerated charge carriers in the absorber layer of the array was calculated by Monte-Carlo simulation. Methods of reducing the amount of necessary calculations based on using the symmetry properties of the array are discussed. Requirements for the photoelectric and design parameters (absorber-layer thickness, chargecarrier diffusion length and optical absorption length in this layer, the ratio of the size of n–p junctions to the geometrical dimensions of the detector pixels) are formulated that ensure the threshold sensitivity and spatial resolution of IR FPAs.     

Multichannel Confocal Microscope Based on a Diffraction Focusing Multiplier with Automatic Synchronization of Scanning

Implementation of a laser scanning confocal microscope is described, where the specimen is scanned by an array of illuminating beams, which significantly increases the velocity of object image construction. The array formation is provided by using a diffractive optical element. Scanning by the array of laser beams over the specimen is performed by galvanometric scanners with moving refractive plane-parallel plates. Owing to application of such a scanning device, the beams in the illuminating channel and the signal beams in the receiving channel pass through one motionless array of confocal diaphragms; as a result, the scanning beams in the specimen plane and the signal beams in the plane of the photodetector matrix can be used without an additional synchronized pair of scanners. The proposed confocal microscope can be applied in problems that require a fast response.     

Regulation of carbon potential in case-hardening units using electrochemical sensors and microcomputers

Scientific-Production Union "VNIITMASh." Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 5, pp. 21–24, May, 1990.     

Features of the sulfocarbonitriding process for high-speed steel R6AM5

Leningrad Institute of Water Transport. Production Association Kirovskii Zavod. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 27–31, July, 1990.     

Predicting the physicochemical wear of an abrasive grain in grinding

Physicochemical wear in grinding is due to the intense interaction of the abrasive and the blank. A system of chemical-affinity coefficients is proposed for abrasive and machined materials, characterizing the intensity of the physicochemical processes in the contact zone.     

Effect of Molecular Additives on the Ignition of Methane–Air Mixtures

Combustion, Explosion, and Shock Waves - The ignition of methane–air mixtures with additives of ClF5, ClF3, OF2, and H2O2 (additive content in the mixtures  $$\le$$ 1%) is studied by...     

Block Diagram of Chemical Transformation in an Fe2O3/Al/AlN Wave Combustion in Nitrogen

Combustion, Explosion, and Shock Waves - The stages of chemical transformation in the combustion wave of an Fe2O3/Al/AlN exothermic mixture in nitrogen atmosphere is studied using an original...