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  • Informational database model for accounting of the teachers workload of an educational organization

    This paper presents an information model of a relational database developed by the authors, designed to take into account the teachers workload of an educational organization. The identification of the subject area entities, their decomposition and the relationships identification between them are carried out. The constructed database model was brought to the Boyes - Codd normal form. Based on the designed database schema, its physical implementation and filling with test data was carried out. The results of test queries showed the developed model adequacy and the its practical applicationp ossibility. It is currently in trial operation at the Department of Information Systems and Computer Modeling, Volgograd State University. With minimal changes, the developed database schema can be applied to account for the teachers workload in various educational organizations.

    Keywords: database, information modeling, "entity-relationship" diagram, decomposition, information system, educational organization

  • Phonon properties of hydrogenated carbon nanofilms

    In this work, the phonon format of graphane nanoribbons is calculated in the Hamiltonian formulaism. The geometric model is presented in the form of a graphene plane with hydrogen atoms attached to it. The unit cell of graphane contains two carbon atoms from solid graphene and two carbon atoms. The curvature of the graphene plane as a result of attachment to hydrogen atoms and hybridization of the outer electron orbitals of carbon atoms from sp2 to sp3, as well as the interaction between hydrogen atoms, are not taken into account. Analysis of the obtained phonon spectra shows that, for any type and width of graphane nanoribbons, there is a gap between acoustic and optical vibrational modes, in contrast to graphene, which can serve as an indicator for a given structure. Also, for the material under study, the values ​​of the speed of sound and the Debye temperature were calculated.

    Keywords: graphene, graphane, nanoribbon, unit cell, vibrational spectrum, dispersion equation

  • Optimization of the reanodization in the production of tantalum oxide-semiconductor capacitors

    A complex of technological operations for the formation of a cathode liner based on manganese dioxide is of particular importance in the production of tantalum oxide-semiconductor capacitors. Electrical characteristics and reliability indicators of capacitors are laid at this stage in their manufacture. In according with the classical technology, the formation of a semiconductor coating of MnO2 on tantalum capacitors is associated with multiple heating of oxidized anodes with the previous impregnation in solutions of manganese nitrate. It has a negative effect on the quality of the Ta2O5-dielectric. To minimize the defect formation in the dielectric, is realized a periodic electrochemical anodization of the tantalum anode in the acetic acid solution by anodic connection of the sections of the capacitors to the direct current source. The authors proposed to modify the process of reanodization of sections of tantalum oxide-semiconductor capacitors by changing the composition of the electrolyte. The results of the investigation of the electrochemical anodizing of a tantalum anode in aqueous solutions of nitric acid and manganese nitrate are presented, the morphology of the obtained coatings, their phase composition, as well as electrical parameters of the sections of capacitors manufactured by the proposed method are analyzed.

    Keywords: Tantalum oxide-semiconductor capacitor, reanodization, manganese nitrate, capacitance, leakage current, dielectric loss tangent, electrolyte

  • Research of the possibility of reducing resistance of the graphite coating in the solid tantalum capacitor

    In recent years, the most widely used semiconductor oxide-tantalum capacitors in high frequency circuits acquired, which causes the need to reduce resistance of the contact and the semiconductor layers. One solution to this problem and at the same time, promising way of improving solid-state tantalum capacitors is to modify process technology for applying the semiconductor layer and heat treatment resistive coating of colloidal graphite. Contact carbon layer according to conventional technology is applied by impregnating the tantalum capacitor sections in an aqueous suspension of colloidal graphite (usually imported), and then produce exposure to air and heat treatment at an elevated temperature. This article presents the results of studies of the effect of conditions of application of the contact layer of colloidal graphite on the electrical characteristics of sections of tantalum oxide-semiconductor capacitor, in particular in the equivalent series resistance, the technique of applying aquadag. Described in detail the design of solid-state tantalum capacitor, the role of the contact carbon layer and its contribution to the ESR of the capacitor.

    Keywords: oxide-semiconductor capacitors, colloidal graphite, resistance of the capacitor, the cathode coating, suspension, immittance, aquadag

  • Chemical regeneration of impregnating solutions Mn(NO3)2 in the manufacturing of oxide-semicanductor capacitors

    "One of the bottlenecks of the production of oxide-semiconductor capacitors is enough fast aging of impregnating solutions of manganese nitrate used to form the cathode electrode of manganese dioxide. This effect is caused by the formation and accumulation of impurities of oxides and nitrides of manganese in the solution, which leads to a poor-quality cathode coating of manganese dioxide on the tantalum anode and as a result, poor performance capacitors. Fast aging of impregnating solutions of the Mn(NO3)2 solutions leads not only to an increase in the cost of materials, but also significantly increases of the volume of waste. As a solution to this problem in the proposed article discusses aspects of chemical regeneration of contaminated solutions of manganese nitrate, analyzed the possible ways of its realization in relation to the existing production of oxide-semiconductor capacitors."

    Keywords: Manganese nitrate, manganese oxides, cathode coating, impregnating solutions, manganese nitrides, manganese oxohydroxide, chemical regeneration.

  • Evaluating of of fuel efficiency in the unified electric power station based on a combustion engine with alternating frequency rotation of shaft.

    The description of the flow sheet of unified electric power station of ship based on a combustion engine by alternating frequency rotation of shaft. The assessment of fuel profitability of such electric power station is given. In article materials of the state contract № 16.526.12.6016 on 11.10.2011 are used.

    Keywords: unified electric power station, explosion engine, synchro generator, synchro motor, converter

  • Modeling of business processes of building company by the ARIS program

    The target of the article consists of explore methodology of the program ARIS and modeling business process of building company. We reviewed how you can visualize and detail any process by the instruments of the ARIS. The most important thing that you can improved performance of your business if you use methodology of modeling business process. This program help to do your activity more understandable for analyzes and future prognoses. By the instruments of the ARIS you can imagine different variants of realization project events

    Keywords: building company, business process; modeling; methodology of the ARIS

  • Architectural ecology. Energy-efficient construction.

    "Current economic problems in the sphere of human environmental organization led to the birth of synthetic science - architectural ecology. Task of energy efficiency and alternative energy sources use in the condition of ecological balance of environment created demand for energy-efficient building design. The search of new approaches and energy-efficient technologies proceeds in two mutually compatible directions: energy-efficient and energy-active homes. Complex approach to the ecological and energy problems solution considering all direction differences. architecture, energy-efficient buildings, energy efficiency, energy-efficient technologies, energy-efficient homes, energy-active homes. "

    Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production

  • Mathematical model of inter-symbol distortion compensation data transfer status distillation devices RAT

    The paper proposes a mathematical model of inter-symbol distortion compensation data transfer status RAT distillation devices using vector-matrix transformation. 
    Keywords: mathematical model, the inter-symbol distortion distilleries RAT operator transfer and interaction Preemphasis vector.

    Keywords:

  • Information about authors (№1, 2012)

    Information about authors of issue №1 (2012)

    Keywords: authors

  • Information about authors (№4, 2011)

    Information about authors of issue №4 (2011)

    Keywords: authors