×

You are using an outdated browser Internet Explorer. It does not support some functions of the site.

Recommend that you install one of the following browsers: Firefox, Opera or Chrome.

Contacts:

+7 961 270-60-01
ivdon3@bk.ru

  • Determination of the parameters of semiconductor thermistors of the starting system of electric motors

    The article provides a brief analysis of the processes that occur when starting an electric motor. Mathematical relations modeling the process of starting a direct current motor are presented. Graphical dependences allowing to determine parameters of a thermistor providing an optimum start-up of a direct current machine have been obtained.

    Keywords: starting current, thermistor, starting rheostat, thermal characteristic, DC motor, boundary conditions, torque resistance, idealized rheostat, heat loss, economical starting

  • Dynamic characteristics of rheostats and methodological principles of their synthesisthermistors of the starting system of electric motors

    The article gives a brief analysis of thermal processes occurring during the start-up of an electric motor. Mathematical relations modeling the distribution of thermal energy in the thermistor during the process of starting the DC motor are presented. Graphic dependences are presented, which allow to make arrangement of thermoresistors for the starting rheostat and to determine parameters of the starting rheostat obtained in this way. Application of the starting rheostat made on the basis of thermistors, provide an optimal starting of a DC motor.

    Keywords: control gears, thermistor, starting rheostat, DC motor, temperature, dynamic characteristic, form of starting current

  • Optimization of starting processes using semiconductor thermisto

    The article provides a brief analysis of the starting processes of electrical devices. The mathematical formulation of the problem of synthesis of starting rheostats is formulated and its solution is proposed. The main condition for optimal starting of electric motors using thermistor rheostats is presented. Optimal diagrams of the starting current and set of revolutions are given. and also, the change in heat losses in the anchor chain. Recommendations on the layout of starting rheostats are given.

    Keywords: thermistor rheostat, optimal start-up, thermal start-up characteristic, optimal control problem, DC motor, boundary conditions, speed

  • Electrophysical and Thermal Characteristics of Semiconductor Thermal Resistances of Coaxial Type

    High-current semiconductor polycrystalline thermistors of high power of coaxial type have a large mass and consequently, considerable heat capacity and heat resistance. Due to this, the thermophysical and electrophysical processes in them are different in the steady and transient regimes, which is especially important in regimes. which lasts a fraction or a unit of seconds. The main variants of operation of such thermistors in dynamic modes are considered and various characteristics are given.

    Keywords: Thermistor, thermal and electrophysical characteristics, electric motors, electrophysical and thermal characteristics of semiconductor thermo-resistors of coaxial type

  • Theoretical work basis and design philosophy of highcurrent coaxial type termoresistors

    Thermoresistors nowadays are used not only as parts of temperature sensors and flowmeters but they are used as components of starting and control devices. Use of low-powered thermoresistors as starting and control devices parts needs a lot of devices that reduces equipment reliability. Current step-up running through motor-starting devices simplifies control circuit. For using thermoresistors in electric circuits with high-discharge rate it is necessary to use special constructions in order not to let termoresistor body be overheated. Thermoresistor expansion results in changing of thermal fields distribution pattern inside this semiconductor. The authors show calculated characteristics which let determine proportions and shapes of semiconductor subject to thermoresistor temperature.

    Keywords: high power thermoresistors, thermoresistors of coaxial type, current density, temperature, analogy criterion, thermal conductance, temperature gradient, thermal field, stability criterion

  • "Polycrystal temperature dependent semiconducting resistances of coaxial type and starting devices based on them "

    Nowadays the rolling stock is equipped with electric drive of high power. Frequency turning regulation, motor protection from overheating and limitation of starting currents are made with the help of semiconductor elements. For reliability improvement of starting and regulating facilities it is reasonable to use low component count. Running through regulating facilities current decrease simplifies electric circuit configuration. The authors propose to use thermal resistors as main elements. In the article the authors examine construct specifications of polycrystal temperature dependent semiconducting resistances of coaxial type and their advantages. There are some theoretical propositions which describe the work of thermal resistors and also some algorithms for synthesis of coaxial type starting devices. The authors made mathematical modeling for starting devices of different types based on thermal resistors. In the article there are some graphical dependences describing starting process.

    Keywords: high power thermal resistors, thermal resistors of coaxial type, current density, specific generations of heat, criteria of similarity, starting device, starting current, synthesis of starting devices

  • 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