Computational algorithm for solving problem of optimal boundary-control with nonseparated boundary conditions

The problem of optimal boundary-control with nonseparated boundary conditions is considered in the case where the motion of a plant is described by a system of nonlinear ordinary differential equations with a corresponding initial condition, which thereafter is taken as a control action. First, the system of corresponding nonlinear Euler–Lagrange equations is described and in order to solve it, the quasi-linearization method (the first method) is taken. After that, the quasi-linearization method is used with the aim to solve just the optimization problem with boundary control and the nonseparated boundary condition; as a result, the initial nonlinear problem is reduced to the solution of a corresponding linearly quadratic optimization problem (the second method). By the particular example (of oil production) we demonstrate that the second method converges considerably faster and its accuracy is five times higher than the accuracy of the first method. The numerical results reinforce the compliance of the constructed mathematical model with practice.     

Low-carbon steel for magnetic systems in automobile generators

The use of cold-rolled low-carbon steel strip in stators improves their magnetic and current-speed characteristics and simplifies the production process.     

A new technology of the immobilization of nanoparticles in polymers and the development of piezoelectrics based on a hybrid matrix of nano- and micropiezoceramic composites

Given the rapidly developing areas of physical and chemical sciences, the physics and chemistry of a new class of piezoelectric materials on the basis of a hybrid matrix of nano- and mikropyezoelektric composites has arisen. For this goal, we developed the following technologies of hybrid composites and a method of controlling the nanostructure of the polymer phase: (1) the immobilization of nano-sized dielectric particles in a polymer solution using the energy of the plasma channels of powerful electric discharges in air bounded by dielectrics, (2) the creation of active centers in the composites of clusterization by crystallizing them in terms of the plasma electric discharge in an electronegative gas environment, and (3) the control of the polymer phase of the composite by the spectrum analysis of the thermodepolarized current. A technology of obtaining a matrix of hybrid piezoelectric-based nanocomposites and micropezoelectrics is proposed. We propose possible mechanisms for the effects of the immobilization and formation of active origins of clusterization centers of nanoparticles in the polymer phase of the composite.     

Molecular system bioenergics of the heart: experimental studies of metabolic compartmentation and energy fluxes versus computer modeling

In this review we analyze the recent important and remarkable advancements in studies of compartmentation of adenine nucleotides in muscle cells due to their binding to macromolecular complexes and cellular structures, which results in non-equilibrium steady state of the creatine kinase reaction. We discuss the problems of measuring the energy fluxes between different cellular compartments and their simulation by using different computer models. Energy flux determinations by (18)O transfer method have shown that in heart about 80% of energy is carried out of mitochondrial intermembrane space into cytoplasm by phosphocreatine fluxes generated by mitochondrial creatine kinase from adenosine triphosphate (ATP), produced by ATP Synthasome. We have applied the mathematical model of compartmentalized energy transfer for analysis of experimental data on the dependence of oxygen consumption rate on heart workload in isolated working heart reported by Williamson et al. The analysis of these data show that even at the maximal workloads and respiration rates, equal to 174 μmol O(2) per min per g dry weight, phosphocreatine flux, and not ATP, carries about 80-85% percent of energy needed out of mitochondria into the cytosol. We analyze also the reasons of failures of several computer models published in the literature to correctly describe the experimental data.     

Multichannel telemetric system for seismo-acoustic signal interference monitoring of earthquakes

Principles for the construction of a multichannel telemetric system of seismo-acoustic signal interference monitoring of microscopic changes in the technical state of socially significant structures, the point when anomalous seismic processes first appear, and short-term prediction of earthquakes on the basis of signal interference technologies and binary position technology used in the analysis of noise-contaminated signals are proposed. A method of acquiring seismo-acoustic information from deep strata of the Earth by means of the steel shafts of corrosion-proof oil wells in depleted fields is also proposed.     

Deterministic stochastic resonance in a bistable semiconductor system

The phenomenon of deterministic stochastic resonance has been experimentally observed and studied for the first time in a bistable semiconductor system with an S-shaped current-voltage characteristic exhibiting a transition to chaos via intermittency. Spectral regions featuring amplification of an external signal and phase locking are determined as dependent on the frequency and amplitude of the external signal and the control parameter.     

Selective adsorption of organic sulfur-containing compounds from diesel fuel using type-Y zeolite and γ-aluminum oxide

Samples based on type-Y zeolite and aluminum oxide (γ-Al₂O₃) with immobilized Cu(I) ions used as adsorbents of molecules of thiophene derivatives during the desulfurization of diesel fuel were investigated. An analysis of diesel fuel after the desulfurization process showed that a decrease in sulfur content caused by contacting adsorbents amounts to 40–80%. Porous structure parameters of the adsorbents before and after contacting diesel fuel were determined using adsorption isotherms of nitrogen vapor at 77K. Desulfurization processes are shown to influence the porous adsorbent structure; therefore, the specific surface and pore size decrease. According to X-ray diffraction, the data on changing the porous adsorbent structure in the desulfurization process are stipulated by the deposition of sulfur and carbon. It was ascertained that the samples based on HY/Cu(I) zeolite better adsorb sulfur-containing compounds than γ-Al₂O₃/Cu(I) do. An analysis of the IR spectra of adsorbent samples after desulfurization indicates the possibility of chemisorbing aromatic components of diesel fuel, most notably sulfur-containing compounds on the surfaces of all investigated samples with the simultaneous transformation of these compounds mainly into aliphatic-type structures.     

Electrical and thermoelectric properties of Cu0.75Ni0.125FeTe2

The electrical conductivity, Hall coefficient, and thermopower of Cu_0.75Ni_0.125FeTe₂ have been measured between 80 and 500 K. The results have been interpreted in terms of a three-band model which takes into account, in addition to the conduction band, two overlapping valence subbands. We have determined the energy spacing between the subbands (Δ_{0 K} = 0.002 eV), its temperature coefficient (dΔ/dT = 1 × 10⁻⁴ eV/K), and the effective masses of the heavy and light holes and electrons. With the interband scattering of light holes taken into account, the conductivity has a minimum at ∼190 K. Original Russian Text ? F.F. Aliev, G.G. Guseinov, G.P. Pashaev, G.M. Agamirzoeva, A.B. Magerramov, 2008, published in Neorganicheskie Materialy, 2008, Vol. 44, No. 2, pp. 156–161.     

Features of the hole scattering in electroplastically deformed germanium crystals

The effect of features in the formation of scattering centers in electroplastically deformed germanium single crystals on the electrical properties of the samples were studied. The hole scattering in this material significantly differs from the analogous process in crystals deformed by traditional (e.g., thermoplastic) methods. Possible mechanisms explaining the observed effects are considered.