LSI channel routing algorithms

A new method is proposed and an algorithm is developed for two-wire channel routing in a two-layer board, with horizontal interconnections made in one layer and vertical interconnections in the other layer.Translated from Kibernetika, No. 3, pp. 32–35, May–June, 1991.     

Study of the X-ray optical anisotropy of materials via X-ray interferometry

A new method for studying the X-ray optical anisotropy of materials which is based on the X-ray interferometric technique of measurement is described. Unlike the existing methods, in which the sample under study is placed in the path of one of the interfering beams, the test samples in the proposed method are placed directly in the path of two interfering beams; this eliminates the effect of other factors on the displacement of the interference moirefringes. In this method, moirefringes simultaneously occur during the same exposure both in the absence and in the presence of samples with different orientations of the optical axes. A relative displacement of moirefringes is observed in three different columns of the same beam, which makes it possible not only to simultaneously observe and immediately identify the presence of X-ray optical anisotropy but also to measure the values of refractive indexes n _o and n _e for a given sample (n _o is the refractive index for an emission with the polarization perpendicular to the principal cross section, and n _e is the refractive index for a beam with the polarization in the plane of the principal section and parallel to the optical axis). The new method is used to record the X-ray optical anisotropy of a cellophane film and to measure the values of refractive indexes n _o and n _e for cellophane. It is found that the cellophane film is an X-ray optically positive anisotropic medium.     

Some structures for cascade solar cells

Some versions of new, inexpensive structures of cascade solar cells are presented in this work. Advantages of these structures are described. The suggested structures can be easily realized on the basis of modern technologies.     

An IR-Radiometer with Internal Signal Modulation

An infrared (IR) radiometer electrical circuit on the basis of photoresistors and photodiodes made of silicon doped with zinc (Si<Zn>) as well as the narrow bandgap semiconductor alloy Pb_0.78Sn_0.22Te is presented. In the circuit suggested a bridge with the photoreceiver connected to the radiometer input and immediately fed by signal generators functions as a radiation modulator. The threshold sensitivity turned out on a recorder is 2·10^?13 W·Hz^?1/2 (for the n⁺?n?n⁺ structures made of Si<Zn>, λ=0.8?l.2μm, T=300K); 1.4·10^?15W·Hz^?1/2 (for p⁺?n?n⁺ S-diodes on the basis of Si<Zn>, λ=0.8?1.2μm, T=300K) and 10^?12W·Hz^1/2 (for photodiodes on the basis of Pb_0.78Sn_0.22Te, λ=8?13μm, T=77K).     

Macrokinetics of reaction and thermal explosion in Ni and Al powder mixtures

Chernogolovka. Translated from Fizika Goreniya i Vzryva, Vol. 24, No. 3, pp. 67–74. May–June, 1988.     

A setup for thermodesorption measurements

An ultrahigh-vacuum setup for studying the interaction of ions with a solid by the thermodesorption spectroscopy method has been developed. The residual pressure achieved in the setup after heating is <2 × 10⁻⁷ Pa (the main component of the residual gas is H₂). A sample suspended by two tungsten wires is inserted into the main vacuum chamber through a lock chamber. The sample is heated by thermal radiation from the heater from room temperature to 1600–1700 K. The main features of the setup, the experimental technique, and the calibration of desorption flows are discussed. Examples of results obtained on the setup are presented.     

Determination of Residual Stresses in a Boron Fibre/Aluminium Matrix Composite

In the present work residual stresses in a boron fibre/aluminium matrix composite are determined through an etching method. The inhomogeneous removal of surface layers, due to the different sensitivity of boron and aluminium to alkaline environment, requires the application of a modified technique for the estimation of deformations and the calculation of stresses. The results obtained indicate considerable deviations in both distribution and magnitude of residual stresses in the same MMC, due to different fabrication methods. N. P. Andrianopoulos: Corresponding author.