The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform

K. Watanabe - One of the best experts on this subject based on the ideXlab platform.

  • Development of two types of high temperature calorimeters
    Thermochimica Acta, 2000
    Co-Authors: T. Matsui, Yoh Arita, K. Watanabe
    Abstract:

    For heat capacity measurement of ceramic materials at high temperatures above 1500 K, two new calorimeters, i.e. a high speed cooling calorimeter and an advanced-Direct Heating pulse calorimeter, have been developed in our laboratory. The high speed cooling calorimeter is assembled of an induction Heating furnace, a paraboloidal mirror and a high speed six-wavelength pyrometer. In this calorimeter, the heat capacity is determined from the cooling rate of a sample dropped from the induction Heating furnace. As a simulation of a dropped specimen, two different experiments on transient modes were made using a calibrated tungsten lamp in the temperature range 2060-2180 K: (1) by changing temperature with time (cooling curve measurement), and (2) by changing the position of a tungsten lamp vertically at constant temperature. Both results show reliability of this calorimeter at high temperatures. The advanced Direct Heating pulse calorimeter is a re-designed and reconstructed apparatus of the Direct Heating pulse calorimeter previously developed in our laboratory to increase the measuring temperature for the heat capacity up to 2000 K. By the improvement of a new vacuum vessel, molybdenum thermal insulator and tantalum Heating wire, heat capacity and electrical conductivity of graphite could be measured up to 1750 K. (C) 2000 Elsevier Science B.V.

Sergey Matvienko - One of the best experts on this subject based on the ideXlab platform.

  • Determination of composition based on thermal conductivity by thermistor Direct Heating method
    Eastern-European Journal of Enterprise Technologies, 2020
    Co-Authors: Sergey Matvienko, Vadim Shevchenko, Mykola Tereshchenko, Anatolii Y. Kravchenko, Ruslan Ivanenko
    Abstract:

    Thermophysical properties of various substances and mixtures were studied by the non-destructive method. It is proposed to determine the thermal conductivity of substances and mixtures by the thermistor Direct Heating method. The device was created for measuring the thermal conductivity of various substances and mixtures, the operation of which is based on measuring the temperature of thermistor Heating in the test substance. The nonlinear nature of the obtained thermistor Heating dependence is taken into account. Based on the studies, the possibility of determining the composition of the mixture by its thermal conductivity coefficient is shown. The results of experimental studies with reference liquids, solutions of sugar, glycerin and alcohol in water are presented. The results of the studies to determine the thermophysical properties (TPP) of biological substances (human blood and blood plasma, egg white and yolk and others), some vegetables using the method of thermistor Direct Heating in the temperature range from +25 °С to +40 °С are given. It is substantiated that when studying the TPP of substances by thermistor Direct Heating, it is possible to determine the composition of mixtures by their thermal conductivity, but it is necessary to take into account individual properties of the studied liquids. Recommendations are given for studying the TPP of substances and determining the composition of mixtures by their thermal conductivity, taking into account individual properties of the studied substances. Using the proposed method of thermistor Direct Heating to determine a mixture of solutions, biological materials and food products allows analyzing the composition of nanosubstances, obtaining reliable data on the degree of allergic reaction, and in determining the composition of food products – taking into account the data obtained when developing refrigeration equipment and extending the shelf life of products while maintaining their useful qualities.

  • Investigation Thermal Conductivity of Biological Materials by Direct Heating Thermistor Method
    2018 IEEE 38th International Conference on Electronics and Nanotechnology (ELNANO), 2018
    Co-Authors: G. Tymchik, S. Vysloukh, N. Tereshchenko, Sergey Matvienko
    Abstract:

    This work is devoted to determination coefficient of thermal conductivity for biological materials by developed multichannel device, the principle is based on Direct Heating thermistor method. Provided the experimental studies results with standard liquids and biological materials obtained with the use of this device. The results of conducted researches for thermophysical characteristics of biological materials by the multiple method taking into account the individual properties of substance have been substantiated.

  • Effect of the Convection Processes in Liquid on Thermal Conductivity Measurement Error by Direct Heating Thermistor Method
    Research Bulletin of the National Technical University of Ukraine "Kyiv Politechnic Institute, 2017
    Co-Authors: G. Tymchik, Andrey M. Matvienko, Mykola F. Tereschenko, Sergey Matvienko
    Abstract:

    Background. The problems of choosing the optimal utensil diameter for the test liquids on the basis of the investigation of the convection phenomenon effect on the error when measuring the thermal conductivity of liquids by the method of Direct Heating of a thermistor are considered. Objective. The aim of the paper is to carry out experimental studies to determine the effect of the convection phenomenon on the error in measuring the thermal conductivity of liquids. Methods. An estimation of the thermistor Heating temperature measuring accuracy by the method of Direct Heating of the thermistor for the test liquid in utensils of different diameters in determining the coefficient of thermal conductivity is carried out. Series of experimental research was carried out with the help of a device for measuring the liquids TPC in order to determine the optimum design of the probe and the thermostat, to select the optimum volume of the material research and to choose the materials of construction. Results. The results of experimental research with control liquids using the developed instrument based on the method of Direct Heating of the thermistor are presented, the thermistor Heating temperature fluctuation values depending on the utensil diameter with the test liquid are determined. Conclusions. It is substantiated that when designing devices for measuring the TPC of liquids, it is necessary to take into account the individual properties of the liquids under investigation and to create the greatest possible uniform Heating or cooling of the utensil with the test material. Also, it is necessary to use the minimum diameter utensils. It is recommended to use utensils for the test liquid with a diameter of up to 10 mm to reduce the error in measuring the liquid thermal conductivity.

  • Thermal Conductivity Measurement of Solid Materials by Thermistor Direct Heating Method
    Research Bulletin of the National Technical University of Ukraine "Kyiv Politechnic Institute, 2017
    Co-Authors: Sergey Matvienko, Sergei Visloukh, Kostiantyn Filonenko
    Abstract:

    Background. This work addresses the development of an experimental device and increasing the accuracy of determining the thermal conductivity of solid materials by thermistor Direct Heating method. Objective. The aim of the paper is to create the installation, conduct experimental studies to determine the value of the thermal conductivity of solid materials by thermistor Direct Heating method and to research destabilizing factors that affect the measurement error, and to suggest ways to increase the accuracy of measurements. Methods. Experimental device has been created, which work is based on the Direct Heating method of the thermistor and necessary researches have been carried out. The results of the measurement are given by setting the thermal conductivity coefficients of various materials, which make it possible to expand the scope of the method. Results. Rational operating modes and design of probes for measuring the thermal conductivity of solid materials depending on their TPC are proposed and justified. Ways to reduce the measurement error by thermistor Direct Heating method are presented. Investigation of destabilizing factors influencing the measurement error made it possible to determine means of reducing their influence on the results of determining the thermal conductivity of solid materials and to suggest ways to increase the accuracy of measurements. Conclusions . The experimental device has been tested experimentally and implemented in the research and production activities of “VIRCOM” and in the educational process of the Department of Instrumentation Design and Engineering of the National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute” .

T. Matsui - One of the best experts on this subject based on the ideXlab platform.

  • Development of two types of high temperature calorimeters
    Thermochimica Acta, 2000
    Co-Authors: T. Matsui, Yoh Arita, K. Watanabe
    Abstract:

    For heat capacity measurement of ceramic materials at high temperatures above 1500 K, two new calorimeters, i.e. a high speed cooling calorimeter and an advanced-Direct Heating pulse calorimeter, have been developed in our laboratory. The high speed cooling calorimeter is assembled of an induction Heating furnace, a paraboloidal mirror and a high speed six-wavelength pyrometer. In this calorimeter, the heat capacity is determined from the cooling rate of a sample dropped from the induction Heating furnace. As a simulation of a dropped specimen, two different experiments on transient modes were made using a calibrated tungsten lamp in the temperature range 2060-2180 K: (1) by changing temperature with time (cooling curve measurement), and (2) by changing the position of a tungsten lamp vertically at constant temperature. Both results show reliability of this calorimeter at high temperatures. The advanced Direct Heating pulse calorimeter is a re-designed and reconstructed apparatus of the Direct Heating pulse calorimeter previously developed in our laboratory to increase the measuring temperature for the heat capacity up to 2000 K. By the improvement of a new vacuum vessel, molybdenum thermal insulator and tantalum Heating wire, heat capacity and electrical conductivity of graphite could be measured up to 1750 K. (C) 2000 Elsevier Science B.V.

F. Boisen - One of the best experts on this subject based on the ideXlab platform.

  • decontamination of drinking water by Direct Heating in solar panels
    Journal of Applied Microbiology, 1998
    Co-Authors: A Fjendbo J Jorgensen, K. Nøhr, H Sorensen, F. Boisen
    Abstract:

    A device was developed for Direct Heating of water by solar radiation in a flow-through system of copper pipes. An adjustable thermostat valve prevents water below the chosen temperature from being withdrawn. The results show that it is possible to eliminate coliform and thermotolerant coliform bacteria from naturally contaminated river water by Heating to temperatures of 65 °C or above. Artificial additions of Salmonella typhimurium, Streptococcus faecalis and Escherichia coli to contaminated river water were also inactivated after Heating to 65 °C and above. The total viable count could be reduced by a factor of 1000. The heat-resistant bacteria isolated from the Mlalakuva River (Tanzania) were spore-forming bacteria which exhibited greater heat resistance than commonly used test bacteria originating from countries with colder climates. To provide a good safety margin it is recommended that an outlet water temperature of 75 °C be used. At that temperature the daily production was about 50 l of decontaminated water per m2 of solar panel, an amount that could be doubled by using a heat exchanger to recycle the heat.

  • Decontamination of drinking water by Direct Heating in solar panels
    Journal of Applied Microbiology, 1998
    Co-Authors: A. J. Fjendbo Jørgensen, K. Nøhr, H Sorensen, F. Boisen
    Abstract:

    A device was developed for Direct Heating of water by solar radiation in a flow-through system of copper pipes. An adjustable thermostat valve prevents water below the chosen temperature from being withdrawn. The results show that it is possible to eliminate coliform and thermotolerant coliform bacteria from naturally contaminated river water by Heating to temperatures of 65 degrees C or above. Artificial additions of Salmonella typhimurium, Streptococcus faecalis and Escherichia coli to contaminated river water were also inactivated after Heating to 65 degrees C and above. The total viable count could be reduced by a factor of 1000. The heat-resistant bacteria isolated from the Mlalakuva River (Tanzania) were spore-forming bacteria which exhibited greater heat resistance than commonly used test bacteria originating from countries with colder climates. To provide a good safety margin it is recommended that an outlet water temperature of 75 degrees C be used. At that temperature the daily production was about 501 of decontaminated water per m2 of solar panel, an amount that could be doubled by using a heat exchanger to recycle the heat.

Yu Shun Cheng - One of the best experts on this subject based on the ideXlab platform.

  • The study of Direct Heating billet within the forging dies using resistance method
    Materials Research Innovations, 2020
    Co-Authors: Fang Sung Cheng, Yu Shun Cheng
    Abstract:

    This paper reports a simple and effective method to increase Heating efficiency and forming temperature-sensitive materials during the hot forging process. In this study, a resistance type of equipment was set into the forging die and the billet was Directly resistance heated through the forging die. On the basis of this innovative forming method, the Heating effect for the billet appears to be the most dominant factor. The experimental result indicates that the billet could be heated quickly to 1000°C in about 5 seconds and the high-strength material was successfully formed to the shape of a bolthead. With this mechanism, the rapid Heating and isothermal deformation during the hot forging process can be successfully achieved.

  • One-Step Gradual Forging Process by Using Direct Heating Billet within Die
    Applied Mechanics and Materials, 2015
    Co-Authors: Fang Sung Cheng, Yu Shun Cheng
    Abstract:

    Direct Heating billet within a die by using resistance Heating method was developed to form the high strength material in one-step gradual forging process. During the forging process, the pressing speed of the upper die is controlled with the pace of the Heating billet. In the proposed method, the forging die can be used as both the forming and Heating of the billet. Based on this innovative forming method, experimental result shows that the billet could be heated quickly to 1000oC in about 5 seconds and the high strength material was successfully formed to the shape of bolt head in one-step gradual forging process. With the proposed mechanism, the rapidly Heating and gradual deformation during the hot forging process can be successfully carried out.

  • Direct Heating Billet within Die during Hot Forging Process
    Applied Mechanics and Materials, 2013
    Co-Authors: Fang Sung Cheng, Yu Shun Cheng
    Abstract:

    This paper reports a simple and effective method to increase Heating efficiency and decrease Heating time that renders Direct Heating billet within die using resistance Heating system during hot forging process. The apparatus employs resistance equipment set into the forging die, and the billet was Directly resistance Heating by the forging die. Base on the approach, the die as a forming condition on Direct Heating and forging was also researched. The result of experiments shows that the billet could be heated quickly to 1000°C in about 5 seconds and the high strength material (AISI4140) was successfully formed to the shape of bolt head. With this mechanism, the rapidly Heating and isothermal deformation during the hot forging process can be achieved.