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  • Technology of hardening and balancing of abrasive circles

    Results of development of new high-performance technology of hardening and balancing of abrasive circles due to drawing detonation ceramic coverings are presented. The method of calculation of rational thickness of the ceramic covering creating in volume of a circle favorable residual squeezing tension is given. The way of balancing of abrasive circles at the expense of the uneven thickness of the covering put on their lateral surfaces is shown. Results of researches of influence of the sizes of abrasive circles at a size of residual tension are presented.

    Keywords: Abrasive circle, hardening of an abrasive circle, detonation covering, balancing, internal tension

  • Model development of laser radiation interaction with biological tissues

    The mathematical model of laser radiation  thermal influence on biological structures is presented in this article.The optical and thermal parameters anisotropy of biological structures is considered in model. The surface cooling processes are described also with the convection and radiation. The software on the basis of numerical methods and the received model is developed. The  simulation results of influence of two types of lasers (erbium (λ = 2,94 microns) and CO2 (λ= 10,6 microns) ) on the biological structure are given. This structure consists of enamel and a dentine.

    Keywords: laser biotechnologies, numerical simulation, temperature field

  • Model analysis of electrodynamic parameters of a double-gap klystron cavity

    In the article a double-gap cavity with anti-phase excitation that has wide application in designs of floating-drift klystrons is considered. One of the ways of reduction of time during machine design of klystron’s cavity is using of the simple analytical expression, allowing to determine the main klystron electrodynamic parameters with a sufficient accuracy for practice. In the article we presented the results of physical and mathematical modeling of the double-gap cavity, the corrected mathematical models were introduced that can be utilized in programs of a prompt optimization of klystron's type devices. The technique of creation of approximate mathematical model in this case was reduced to definition of basic analytical function, and the subsequent approximation between experimental and calculated data by means of a method of planned experiment. In presented work the analysis of adequacy was carry out. Analysis revealed inaccuracy of a resonance frequency of an anti-phase type in chosen ranges of change of influencing factors doesn’t exceed 1%, characteristic impedance- 5%. The received analytical ratios allow carrying out quickly calculation of parameters of the cavity, without labor-consuming and expensive experiments and calculations.

    Keywords: double-gap cavity, electrodynamic parameters, mathematical simulation, resonance frequency, characteristic impedance, method of planned experiment

  • Modeling of electrodynamic parameters of a multi-mode double-gap cavity for using in miniaturized multi-beam klystron’s devices

    For miniaturized vacuum klystron type devices utilization of a double- gap strip-line cavity with suspended ceramic substrate is very promising. 
    The two-mode operating mode of such cavities practically isn't studied enough; so there is the great scientific and practical interest for research of electrodynamic characteristics of cavities during multi-mode operation that correspond to simultaneous excitement of anti-phase and co-phase modes in a double gap.  
    In this article results of the 3-D numerical modeling by means of the Ansoft HFSS code are presented, and also the experimental results of the electrodynamic properties of the half-wave double- gap cavity with the suspended ceramic substrate are submitted. Optimum parameters of this design, allowing to carry out simultaneous excitement at multiple frequencies with frequency rate (K=2) are determined.
    In such cavity high values of unloaded Q factors isn’t need because dielectric losses and conductor losses can be compensated at the expense of  the negative electronic conductivity that brought by modulated electronic beam. The operating mode with frequency rate   can be used for increasing of efficiency of generating and amplifying micro devices with filament cathode and matrix field emission cathodes.  

    Keywords: double-gap cavity, electrodynamic parameters, mathematical simulation, resonance frequency, characteristic impedance, method of planned experiment

  • The effect of solar radiation on temperature of soil

    To describe the dynamics of the temperature field in the surface layers of the earth taken up the heat balance of the earth's surface. Taken into account are three components of the heat flow: convective heat transfer with air, solar radiation, heat flow from the surface layers of the soil. The boundary conditions on the surface of the soil is considered the temperature of the ground surface, which is determined from the heat balance of the surface layer of the sun radiation. The temperature distribution in the soil is determined using the method of finite differences. A layer of soil has a certain thermal inertia, which leads to delaying the achievement of minimum temperatures in the soil column relative to the time of achievement of the minimum surface temperature. In the surface layer of soil to a depth of approximately 300 mm, is almost complete attenuation of the diurnal temperature fluctuations in the month of June with account of solar radiation in conditions of the South of Russia.

    Keywords: heat pump, возобнавляемые sources of energy, solar radiation, transient mode, soil

  • Mathematical and statistical models predicting efficiency of surgical treatment of certain diseases

    Article focuses on the use of statistical models to predict tolerability surgery using intracavitary hyperthermic chemotherapy (IHCT) and the definition of indications and contraindications to perform operations and tolerability for patients with cancer based on the hemostatic patient. This technique allows a high enough accuracy to prediction portability planned surgery, duration of disease-free period, the period and quality of life in the immediate and late postoperative period.Improve treatment of patients with malignant tumors of the abdomen and pelvis, is one of the priorities of modern health care. Relevance of various parameters of immunity, clinical and biological parameters of homeostasis and prognosis of malignant disease in humans will significantly reduce the proportion of late diagnoses of relapses. Recently there has been increased research to find a method of complex cytoreductive surgery and the use of cytotoxic drugs, and physical therapies, one of which is a local intraoperative hyperthermic chemotherapy. With the help of statistical methods has been studied the degree of influence on the parameters IHCT immunity and an estimate of the nature of the immunological changes in different types of surgery. Methods of binary logistic regression analysis was calculated diskriminatnogo forecast portability operation - patient survival probability. Based on the method of multiple regression were obtained algorithms calculate the duration of life of patients after surgery, and the duration of DFS. Studies based on the factor analysis showed that the main factors affecting the prognosis of disease-free period and the period of life are the morphological structure of the tumor volume cytoreduction, the sum of your immune system and cancer markers. Peritoneal cancer index, sex and age of the patient does not have a significant effect on these parameters. Thus, the introduction into clinical practice of the proposed computer systems and statistical forecasting models allow physicians to objectively evaluate the performance of homeostasis, the portability of the planned surgery, more accurately predict the course of the cancer disease and the likelihood of recurrence of the disease and the duration and quality of life.

    Keywords: statistics, modeling, forecasting, surgery, colorectal cancer, disease-free life expectancy, tolerance of surgery, immunological parameters, factor analysis, regression equation

  • Information about authors (№1, 2013)

    Information about authors of issue №1 (2013)

    Keywords: authors

  • Simulation of the temperature field in the ground

    Discusses issues of modeling of thermal regime of soil in harmonious fluctuations in air temperature. Developed mathematical model to predict the temperature distribution. Is an example of the calculation for the summer mode  

    Keywords: Heat pump, ground heat exchangers, numerical methods, unsteady mode

      The article shows that the viscoelastic behavior of polymers is well described by a nonlinear generalized Maxwell equation, generalized Russian scientists GI Gurevich In this paper, based on the results of experimental studies of the isothermal relaxation of thermal stresses presented a method to determine the relaxation parameters of the equation. The experiment was carried out on thin-walled tubes, with rigidly clamped ends. Heating or cooling from initial temperature to a final temperature (the temperature relaxation time) was carried out at a constant rate of heating (cooling) in a linear fashion. This work shows that the linearized theory does not give correct results.

    Keywords: Thermal stresses, the Maxwell equations relating the parameters, isothermal relaxation

  • Information about authors (№4 p.1, 2012)

    Information about authors of issue №4 p.1 (2012)

    Keywords: authors

  • Information about authors (№4, 2010)

    Information about authors of issue №4 (2010)

    Keywords: authors