Environmental aspects of thermal power equipment operation modes optimization

The article deals with development of methods for improving the efficiency of power generation in thermal power plants by means of main equipment operating mode optimization. The technique for efficient load distribution between cogeneration turbines for cogeneration of heat and electricity is introduced. The calculated fuel consumption corresponds to the optimal operating modes of turbines. The environmental aspects of optimization method have been considered. The economic effect from implementation of proposed technical solutions has been calculated. For more significant reduction of toxic compounds, generated in boiler furnace, the use of thermal effect from combustion of the hydrogen formed during the decomposition of the damp water, metered into the combustion chamber at temperature 1100 °C is introduced. The use of hydrogen additive as a source of additional stored energy due to combustion in the combustion device, expands the scope of its application in a power system significantly and provides normal emissions of toxic compounds into the air. The use of hydrogen additive in combustion refers to the best available techniques, implementation of which allows increasing the competitiveness of Russian energy production.     

In vivo and in vitro debromination of decabromodiphenyl ether (BDE 209) by juvenile rainbow trout and common carp

Decabromodiphenyl ether (BDE 209), the major congener in the high volume industrial flame retardant mixture "DecaBDE", has recently been shown to be metabolized by carp. To further explore this phenomenon, juvenile rainbow trout were exposed to BDE 209 via the diet for a five month period. Analysis of the whole body homogenate, liver, serum, and intestinal tissues revealed that BDE 209 accumulated in rainbow trout tissues and was most concentrated in the liver. In addition to BDE 209, several hepta-, octa-, and nonaBDE congeners also accumulated in rainbow trout tissues over the same period as a result of BDE 209 debromination. Based on the total body burden of the hepta- through decaBDE congeners, uptake of BDE 209 was estimated at 3.2%. Congener profiles were different among whole body homogenate, liver, and serum, with the whole body homogenates having a greater contribution of the debrominated biotransformation products. Extracts of the rainbow trout whole body homogenates were compared with extracts from a previous experiment with common carp. This comparison revealed that BDE 202 (2,2',3,3',5,5',6,6'-octabromodiphenyl ether) was a dominant debromination product in both studies. To determine whether the observed debromination was metabolically driven, liver microsomal fractions were prepared from both common carp and rainbow trout. Analysis of the microsomal fractions following incubation with BDE 209 revealed that rainbow trout biotransformed as much as 22% of the BDE 209 mass, primarily to octa- and nonaBDE congeners. In contrast, carp liver microsomes biotransformed up to 65% of the BDE 209 mass, primarily down to hexaBDE congeners. These microsomal incubations confirm a metabolic pathway for BDE 209 debromination.     

The Study of a Proportional Chamber in the Plasma Mode for the Electromagnetic Calorimeter

The proportional chambers operating in the plasma mode were investigated with the aim of being used in calorimetric measurements. The chambers, simple in design, were blown through with a cheap two-component mixture. Amplitude spectra of the showers produced by 10-GeV electrons were measured with lead plates of differing thicknesses. The chambers were investigated in the absence and presence of the magnetic field aligned with their electric field. The experimental results show that this type of detectors can be used to measure the energy of -quanta.     

Thermoelectric Properties of n-Mg2(SiGe)0.8Sn0.2 Solid Solution

Semiconductors - High values of the thermoelectric figure of merit (ZT = 1.5) in Mg2Si–Mg2Sn solid solutions are caused by a low thermal conductivity and a complex band structure, which is...     

Mechanisms of Molding,Phase Formation,and Structuring of Materials Based in Titanium Borides under the Conditions of Combustion Processes and High-Temperature Shear Deformation

Journal of Engineering Physics and Thermophysics - By the method of x-ray diffraction with a high time resolution, the authors have investigated the phase formation and structuring of titanium...     

A comparison of the temperature dependences of photoeffect quantum efficiencies in GaAs p-n structures and Schottky diodes

A comparison is made of how the quantum efficiencies for photoelectric conversion in p-n-and m-s-structures based on GaAs depend on temperature. For photon energies less than or the same order as the width of the band gap, the temperature dependences of the p-n-and m-s-structures are similar. In the range of photon energies larger than the width of the band gap, the quantum efficiency of p-n-structures is temperature independent, whereas the quantum efficiency of m-s-structures exhibits a strong temperature dependence. A qualitative explanation of this phenomenon is given. Fiz. Tekh. Poluprovodn. 33, 876–879 (July 1999)     

Microstructure and dielectric and piezoelectric properties of PbFe0.5Nb0.5O3 ceramics modified with Li2CO3 and MnO2

Unmodified lead ferroniobate (PFN) and samples modified with 1 wt % Li₂CO₃ (PFNL) and 1 wt % MnO₂ (PFNM) have been prepared by solid-state reactions followed by sintering by a conventional ceramic processing technique. The modifiers have been shown to change the nature of the recrystallization sintering process, reduce the optimal sintering temperature of the material, increase its average grain size, stabilize its dielectric properties, and improve its piezoelectric performance. The observed effects are interpreted in terms of the crystal-chemical specifics of the modifiers and their location in the structure of the parent compound.     

Impact compressibility of a poly(ethylene glycol)-based nanocomposite fluid

The behavior of a poly(ethylene glycol)-based nanocomposite shear thickening fluid (STF) under impact loading conditions has been experimentally studied using the Kolsky method and related techniques. The dependence of the pressure in the STF on the volume strain magnitude has been determined. It is established that the radial and axial components of the stress tensor almost coincide, which shows that the material behaves like an incompressible liquid. The character of the stress-strain curves (hysteresis) indicates that the STF is characterized by some energy dissipation in the load-unload cycle.     

Ultrafine-grain structure and properties of carbon-steel wire after complex deformation

A continuous wire-deformation method is proposed. In this method, which has been patented in Russia, continuously moving wire is subjected simultaneously to tension in drawing, to flexure in a roller system, and to torsion. Metallographic data show that ultrafine-grain structure may be formed in carbon-steel wire. Mechanical tests confirm that the properties of carbon-steel wire may be improved by such deformational treatment.     

The Geometry of the World of Currency Volatilities

Computational Economics - Using empirical data and the properties they reveal, we develop a factor that captures changes of both currency implied correlation and volatilities. For this purpose, we...