Software for Regional Studies: On the Difference-Approximation Approach to Solving Systems of Nonlinear Equations

A scheme of generating efficient methods for solving nonlinear equations and optimization problems which is based on a combined application of the computation methods of linear algebra and the finite-difference approximations of derivatives is proposed. Examples of the new methods constructed with the help of the approach proposed as well as the examples of its possible applications are given below

Petrology and classification of new Antarctic carbonaceous chondrites PCA-91082, TIL-91722 and WIS-91600

Three Antarctic chondrites : Pecora Escarpment (PCA) 91082,Thiel Mountains (TIL) 91722 and Wisconsin Range (WIS) 91600 were studied by SEMEDS methods and classified as CR2,CV3 and CM2,respectively. PCA91082 and TIL91722 contain rare fine-grained refractory inclusions and amoeboid olivine aggregates without any traces of secondary alteration processes. Chondrule pyroxene is enriched in Cr and Mn compared to pyroxenes from refractory inclusions. Presence of Cr^ and Ti^ with normal Cr^ and Ti^ in chondrule pyroxenes probably indicates reducing conditions during chondrule formation. Several unusual objects, such as a compound P-rich chondrule in PCA91082,and P and Cr enriched glasses in WIS91600,were studied. The metal fraction of PCA91082 shows a positive Nivs. Co trend which can be produced by volatilization process. Bulk composition of inclusions and chondrules follows to condensation trend, but exsolution structures and glasses indicate crystallization from melts

FAST ASSEMBLY OF QUALITY SUSPENDED VENTILATED FACADES

Previously understudied new structural and technological concepts of various types of modern suspended ventilated facades (SVF) applicable in Russia by 2017 were researched by a system and analysis method to determine their advantages and disadvantages. Theoretical bases and the algorithm for the development of the optimal technological solution for the installation of SVF were worked out with the aid of the methods of multi-criteria optimization. The structure and the operating sequence were substantiated for the rational technology of integrated mechanized process of SVF elements installation. Alternate improved technological solutions were developed for installation of heat insulating, framing and facing SVF elements with the account of the most important optimality criteria. These criteria include minimum labor intensity and machine time, minimum cost, enhanced quality and safety. Effects of the most important factors related to labor intensity and cost improvement of construction operations as well as increase of SVF useful life under various building conditions were defined and substantiated by experimental construction of residential buildings with SVF facing. With the aid of the methods of alternate technological design and multi-criteria optimization, 4 optimized variants of technological solutions for installation of thermal insulation, frame and facing elements in SVF systems were developed with the account of the 4 most important consumer optimality criteria: minimum labor intensity and machine time, minimum cost, enhanced quality, maximum quality and safety. The scientific significance of the results is that the major factors affecting optimization of technological modes of various SVF designs were identified and studied. Their use allows reducing the labor intensity of works to 0.55–1.79 man-shift per 1 sq. m of facade area

Structure and characteristics of laser crystallized thin amorphous Si films

AbstractPure amorphous Si thin films deposited on oxidized crystalline Si surface (111) were crystallized by picosecond UV laser pulses. The Raman scattering spectra show that pulse energy of 330 mJ/cm2 is enough to fully crystallize Si film and further increase of the energy does not improve crystallinity. A large grained polycrystalline Si was obtained as revealed by surface analysis. A significant increase in carrier mobility was observed after laser crystallization

Onsager coefficients of a Brownian Carnot cycle

We study a Brownian Carnot cycle introduced by T. Schmiedl and U. Seifert [Europhys. Lett. \textbf{81}, 20003 (2008)] from a viewpoint of the linear irreversible thermodynamics. By considering the entropy production rate of this cycle, we can determine thermodynamic forces and fluxes of the cycle and calculate the Onsager coefficients for general protocols, that is, arbitrary schedules to change the potential confining the Brownian particle. We show that these Onsager coefficients contain the information of the protocol shape and they satisfy the tight-coupling condition irrespective of whatever protocol shape we choose. These properties may give an explanation why the Curzon-Ahlborn efficiency often appears in the finite-time heat engines

Quantum thermodynamic processes: A control theory for machine cycles

The minimal set of thermodynamic control parameters consists of a statistical (thermal) and a mechanical one. These suffice to introduce all the pertinent thermodynamic variables; thermodynamic processes can then be defined as paths on this 2-dimensional control plane. Putting aside coherence we show that for a large class of quantum objects with discrete spectra and for the cycles considered the Carnot efficiency applies as a universal upper bound. In the dynamic (finite time) regime renormalized thermodynamic variables allow to include non-equilibrium phenomena in a systematic way. The machine function ceases to exist in the large speed limit; the way, in which this limit is reached, depends on the type of cycle considered.Comment: 14 pages, 12 figures, Replaced by version accepted for publication in European Physical Journal

Thermodynamics of quantum systems under dynamical control

In this review the debated rapport between thermodynamics and quantum mechanics is addressed in the framework of the theory of periodically-driven/controlled quantum-thermodynamic machines. The basic model studied here is that of a two-level system (TLS), whose energy is periodically modulated while the system is coupled to thermal baths. When the modulation interval is short compared to the bath memory time, the system-bath correlations are affected, thereby causing cooling or heating of the TLS, depending on the interval. In steady state, a periodically-modulated TLS coupled to two distinct baths constitutes the simplest quantum heat machine (QHM) that may operate as either an engine or a refrigerator, depending on the modulation rate. We find their efficiency and power-output bounds and the conditions for attaining these bounds. An extension of this model to multilevel systems shows that the QHM power output can be boosted by the multilevel degeneracy. These results are used to scrutinize basic thermodynamic principles: (i) Externally-driven/modulated QHMs may attain the Carnot efficiency bound, but when the driving is done by a quantum device ("piston"), the efficiency strongly depends on its initial quantum state. Such dependence has been unknown thus far. (ii) The refrigeration rate effected by QHMs does not vanish as the temperature approaches absolute zero for certain quantized baths, e.g., magnons, thous challenging Nernst's unattainability principle. (iii) System-bath correlations allow more work extraction under periodic control than that expected from the Szilard-Landauer principle, provided the period is in the non-Markovian domain. Thus, dynamically-controlled QHMs may benefit from hitherto unexploited thermodynamic resources