A Generalized Function in Heat Conductivity Problems for Multilayer Structures with Heat Sources

An accurate analytical solution of the stationary problem of heat conductivity for a multilayer structure with heat sources under asymmetric boundary conditions of the third kind is obtained based on the use of the theory of generalized functions. Using the asymmetric unit function (Heaviside function), the problem for a multilayer structure is reduced to a single-layer with discontinuous (piecewise-continuous) medium properties. By introducing a new independent variable, the nonlinear differential equation (nonlinearity of the second kind—the thermal-physical properties depend on the spatial variable) is reduced to a linear one, direct integration of which allows obtaining an accurate analytical solution of the problem considered. Examples of investigations of the temperature fields for some certain multilayer structures are given.     

Ecology and stable development of the region containing the novovoronezh nuclear power plant

Risk analysis applied to public health is used to evaluate the ecological safety of the territory of Voronezh Oblast, where the Novovoronezh nuclear power plant is located and a new plant is under construction. It is found that for the population of the territory of Voronezh the individual risk of developing cancer because of the contamination of air by chemical carcinogens and the risk of death due to pollutants are 1000–10000 times higher than the risk of developing cancer from the additional irradiation of the population of Novovoronezh associated with the operation of the nuclear power plant. The results obtained showed that modern nuclear technologies have no effect on the public health as compared with sources of chemical risk.     

Nitrogen and fat balance of premature infants in the 1st days of life

Significant nitrogen imbalance was recorded in the presence of satisfactory fat retention in premature infants during the first days of life. It is suggested that along with the biochemically immature processes of protein assimilation aggravated by the perinatal pathology protein deficiency plays an important role in the nitrogen imbalance in the premature infants. To prevent the above disorders the authors recommend that the premature infants be given minimum 1.8-2 g protein/kg bw; long-term milk infusions through a naso-gastric tube could be helpful in this case.     

Calculation of the acid-base equilibrium constants at the alumina/electrolyte interface from the ph dependence of the adsorption of singly charged ions (Na<Superscript>+</Superscript>, Cl<Superscript>−</Superscript>)

A procedure was proposed for the calculation of the acid-base equilibrium constants at an alumina/electrolyte interface from experimental data on the adsorption of singly charged ions (Na⁺, Cl⁻) at various pH values. The calculated constants (pK ₁⁰= 4.1, pK ₂⁰= 11.9, pK ₃⁰= 8.3, and pK ₄⁰= 7.7) are shown to agree with the values obtained from an experimental pH dependence of the electrokinetic potential and the results of potentiometric titration of Al₂O₃ suspensions.     

Shock-wave Processes in the Electric Explosion of Thin-Film Systems on Silicon

Silicon - This study investigates the relationship between thermal shocks on the surface of semiconductor wafers and parameters of thermostimulated mechanical vibrations to develop express methods...