Characterization and imaging of SAW grooved transducer acousticfield by SLAM

Quantitative characterization of the surface acoustic field radiated forward, backward, and in orthogonal directions by the grooved transducer, implemented onto a glass substrate, is accomplished by a scanning laser acoustic microscope (SLAM) operating at 31 MHz. The surface acoustic wave (SAW) amplitude is measured as a function of the number of grooves and the position of the bulk acoustic wave (BAW) transducer. The number of the operating grooves efficiently contributing to the SAW response is estimated. Remarkable reflection of the SAW beam between two identical gratings is observed     

High-temperature oxidation of sintered lanthanum hexaboride

Conclusions The intense interaction between sintered LaB₆ with atmospheric oxygen starts, at temperatures close to 700°C, The mechanism of the process and composition of the interaction products change depending on temperature. Oxidation resistance of LaB₆ up to 1200°C is satisfactory. At higher temperatures, catastrophic oxidation of the material caused by active evaporation of boron oxide takes place.Translated from Poroshkovaya Metallurgiya, No. 11(299), pp. 56–59, November, 1987.     

A phase-shift-keyed-signal decoding method based on the analysis of the complex envelope via an artificial neuron network

A multilevel phase-shift-keyed-signal decoding method based on the analysis of the complex envelope with the help of a neural network is proposed. Received information symbol are determined with the use of a multilayer perceptron. The results obtained by means of computer simulation of decoding of a quaternary phase-shift keyed signal are presented. These results confirm the efficiency of the proposed method.     

Laser Heat Treatment of Ferrocarbon Powder Steel

Russian Engineering Research - The laser heat treatment of sintered ZhGr ferrocarbon powder steel with different porosity is considered. The microstructure and microhardness of the steel are...     

Designing and Preparing a Thin-Film Photocatalyst from Titanium Dioxide Nanotubes Codoped with Nitrogen and Fluorine

Theoretical Foundations of Chemical Engineering - Thin-film nanostructured coatings have been produced electrolytically from TiO2 codoped with nitrogen and fluorine. The resulting films consist of...     

An 8-bit parallel DAC with segmented architecture

An 8-bit parallel DAC with a segmented architecture that employs a 4-bit binary and an unary segments is presented. A switched current source and a thermometric decoder are discussed. A test chip is fabricated using a 180-nm CMOS technology. Measured results show higher conversion rate and smaller chip area in comparison with other papers.