Optimization of Linearly Equalized QAM

A QAM signal transmitted over a channel with linear distortion and additive white Gaussian noise can be linearly equalized at the receiver to eliminate intersymbol interference. If the QAM signal is power constrained and a given symbol error rate is required, we show that it is possible to maximize the bit rate of this system by optimizing the symbol rate and the number of bits/symbol. Ideal linear equalization is assumed at the receiver to overcome the distortion introduced by the channel. As an example, a Gaussian channel is chosen, and the bit rate is maximized for this channel. The QAM maximization is especially useful for channels with slowly decaying channel attenuation characteristics, e.g., the twisted-pair channel.     

Thermodynamic time and microstress tensor in Vakulenko's form

The significance of the concepts of thermodynamic time and microstress tensor introduced by A. A. Vakulenko for development of the theory of viscoplasticity is analyzed.Translated from Problemy Prochnosti, No. 5, pp. 56–58, May, 1991.     

Analysis of performance of fuel elements of the BOR-60 reactor with vibrocompacted uranium-plutonium oxide fuel

Translated from Atomnaya Énergiya, Vol. 66, No. 5, pp. 299–302, May 1989.     

High-speed, polyimide-based semi-insulating planar buried heterostructures

We describe planar buried heterostructure lasers which have low capacitance (lpF), large bandwidth (19GHz), high power (>20mW/facet) and high temperature operation (100°C). These lasers are very suitable for long-distance, highspeed digital and analogue signal transmission.     

Radiation Equivalence and Natural Similitude in Handling Radioactive Wastes

The possibility of long-term safe disposal of radioactive wastes based on their radiation and radiation-migration balance with the initial fuel component and taking account of the thermal, radiation, and elastic loads due to waste dispoasl on the natural medium is examined. The specific radiation and radiation-migration equivalence is established on the basis of the radiotoxicity of uranium and the components of the decay of uranium and individual radionuclides as well as the sum of the latter.     

Rheological behaviour of concentrated yeast suspension

The effect of yeast cell volumetric concentration on the rheological properties of the suspensions was measured in a pipe-flow viscometer at 30°C: at low microbial concentrations the suspensions were Newtonian; however, non-Newtonian behaviour, which could be described by the power-law equation, was observed with suspensions at high microbial volumetric concentrations. At conditions of constant microbial morphology and growth rate, the results also indicated that a relationship could be developed between the power-law constants and the microbial volumetric concentration.     

Theory of MSW transducers

This is a review of two electrical equivalent circuits for multi-element magnetostatic wave transducers. The two circuit models are identified as a transmission line and a two terminal model. Both models have been extended to all three principal MSW modes of propagation to the point where computer programs have been written to plot phase and amplitude response as measured by commercial network analyzers. A review is provided of the basic assumptions, similarities and differences, advantages and disadvantages, and limitations of the two models. The useful range of them covers many cases of practical interest in the one to twelve Ghz frequency range.