An automated device for manufacturing microneedles of iterated shape

A computer-controlled device allows for obtaining metallic microneedles with a vertex radius of ∼10 nm from wire bars by using the electropolishing technique. The microneedles have a highly reproducible shape and a nondisturbed interior microstructure of bars. The essence of the method consists in terminating the process at an optimal instant determined from the time dependence of the electric current by using a computer program. The microneedles obtained are utilized as point electron sources, samples in field-emission microscopy, and indenters in tunneling microscopy.     

Cyaniding steels with the use of triethanolamine

Cyaniding is widely used in basic engineering for surface strengthening of parts. Triethanolamine is often used as the liquid matter in the process. However, cyaniding is often conducted by adding ammonia into the liquid matter, which creates problems with the utilization of the remaineder of the gas. The addition of other gases (nitrogen, argon, etc.) into ammonia is not appropriate because the latter does not decompose completely. The present paper is devoted to the results of industrial tests of a cyaniding technology at 800°C with the use of triethanolamine without ammonia or any other gas or substance. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 2, pp. 8–11, February, 1998.     

Current methods of determination of chlorine in inorganic substances (Overview)

This is an overview of current methods of determination of chlorine in inorganic substances published in the last decade. Challenges of development of ICP-AES for determination of chlorine in aqueous media are demonstrated. Attention is paid to methods of determination not only of total chlorine and chloride ion, but to other forms of chlorine occurrence as well. Particular importance of determination of perchlorate ion is highlighted. Widely applied methods of ion chromatography, potentiometry, and spectrophotometry are presented in combination with flow analysis.     

Nanoparticles in artesian waters

We have proposed the classification of nanoparticles in natural waters by the mechanism of the formation and chemical composition. We have obtained data according to the dimensional spectrum and the content of microelements aluminosilicate particles of artesian waters.