temperature

To study the metrological characteristics, there were studied manufactured based on the Ti-Cu-Co-Si alloy, obtained by quenching from the melt, the sensitive element of the resistance thermotransducer. The instability of its metrological characteristics as a function of temperature up to 350 oC and operation time up to 3000 hours was investigated; it does not exceed 0.025% under the worst operating conditions. In addition, the methodological error of measurement caused by heating of the sensitive element by the measuring current was examined.

Optimization of epoxidation by using response surface methodology (RSM) based on three-level three-factorial central composite design (CCD) was used. Response percentage of relative oxirane content (%RCO) was studied to determine the optimum reaction condition for production of polyols. The predicted value of model (85 %) was excellent in accordance to experimental value (81 %). All parameters (temperature, molar ratio of formic acid to oleic acid and molar ratio of hydrogen peroxide to oleic acid) were significant in influencing the course of epoxidation reaction (p < 0.05).

The kinetics of the process of drying hot (80°C) and cold (20°C) candied pears were studied. The drying coefficient is found and an analytical dependence is derived for the drying time calculation. Experimental data of the change in the temperature of the thermal agent along with the height of the candied fruit layer was obtained.

The article is directed on metrological characteristics increase and extension of the optical thermometry field of use, including two-color compensative thermometry with a priori averaged adjustment. The investigations have been performed for the tungsten. This metal studied in thermometry and metal optics has tabulated quantitative estimations of emissivity which are similar to the most widespread in metallurgy iron-carbon alloys.

In order to increase the capacity and efficiency factor of gas turbines and internal combustion engines while preserving their high reliability, the gas temperature and its distribution need to be measured in combustion chambers. Values of these temperatures can exceed 1800°С in an oxidizing atmosphere. Therefore, designing temperature transducers for measurements in such severe environments, special attention should be paid to the selection of thermometric materials.

A physical and mathematical model for determining the thermostressed state of an electrically conductive cylindrical implant under the action of external unstable electromagnetic fields, in particular the impulse with amplitude modulation, is proposed.  This model allows predicting the maximum allowable values (according to physiological norms) of temperature and stress intensities in the considered implant depending on the parameters of external unstable electromagnetic fields and the time of their action.

A mathematical model for determining the temperature of an electrically conductive plate element under the action of pulsed electromagnetic radiation of the radio-frequency range is proposed.  This model allows us to take into account the influence of the process of thermoelastic energy dissipation on the forecasting of the value of temperature in addition to the joule heat.  This process is determined by thermal expansion and the action of poendromotive forces arising in the element.  This approach allows us to predict a decrease in the error of temperature determination.  On this basis, t

The hard operation conditions of temperature thermotransducers which involve their thermal cycling require special attention to the study of processes occurring in structural elements, in particular in thermometric materials. Operation impacts cause the drift of thermometric characteristics due to the influence of the few factors main of which seem to be the thermo structural stresses.

A mathematical model and the respective structural scheme of the convective heating surfaces of the TPP-210А steam boiler were developed as a system of interconnected heat exchangers. The interconnected convective heating surfaces are regarded as the convective heat transfer system of the boiler.