Dynamics Of Temperature Changes Research Articles

Summer warming during Heinrich Stadial 1 in Northeast China

Abstract The last deglaciation is considered a key period for exploring the underlying dynamics of temperature changes because it was characterized by multiple millennial-scale abrupt climatic events. However, the limited number of quantitative temperature records in Northeast (NE) China covering the last deglaciation hampers a complete understanding of the mechanisms and processes behind the temperature changes that occurred in that region. Here, we present a quantitative reconstruction of summer temperature over the last deglaciation based on bacterial branched glycerol dialkyl glycerol tetraethers (brGDGTs) analyzed from the sediment sequence of Lake Kielguo, a small volcanic lake in NE China. The results show that summer temperature was lowest during the interval ca. 20–18.2 calibrated (cal.) k.y. B.P. with a value of ~11.1 °C and increased by ~1.9 °C during Heinrich Stadial 1 (HS1) and by ~2.7 °C during the transition to the Bølling-Allerød (B-A). The summer temperatures during the B-A warm interval and Younger Dryas cold interval were ~14.1 °C and ~12.0 °C, respectively. The summer temperature record from the Lake Kielguo sediment sequence indicates that summer warming dominated the climate change state during HS1 in East Asia, which is different from the cooling pattern controlled by winter temperatures in the North Atlantic and Greenland realms. This distinction can be explained by weakened winter cooling signals triggered by the collapse of Atlantic Meridional Overturning Circulation when these signals propagated to East Asia, and increased summer temperature warming controlled by orbital and greenhouse gases during HS1 in East Asia.

Determination of heat transfer process in vertical cable tunnels of nuclear power plants under real fire conditions

The object of the study was heat and mass transfer processes occurring in vertical cable tunnels. The problem to be solved was the definition of process mechanisms in the inner space of the tunnel. For this, field tests were conducted, mathematical models were created, and computational experiments were conducted to establish specific parameters that affect the temperature regime of a fire in a vertical cable tunnel of a nuclear power plant. The dynamics of temperature changes with known geometric parameters and fire load were determined, and the adequacy of mathematical models built in the Fire Dynamics Simulator software was investigated and computational experiments were carried out. It has been proven that they consist in determining the temperature regime in a vertical cable tunnel of a nuclear power plant with known technical and geometric parameters. Such studies have practical applications in the field of safety of nuclear power plants and the development of new technologies in this field. An important conclusion of these studies is the possibility of determining the fire resistance of building structures of vertical cable tunnels of nuclear power plants with the selection of the most severe temperature regime, according to the conducted field test. This means that research results can be used in practice in designing and evaluating the safety of such objects. The conducted research established that the temperature in the inner space of the tunnel can reach values from 1200 to 1400 ℃. The following factors influence the maximum temperature value and the maximum time to reach the maximum temperature in the fire cell: fire load, height and area of the tunnel. With a lower fire load, the maximum temperature in the vertical cable tunnel of the nuclear power plant was 75 % lower. Therefore, the results of these studies have a direct practical application in the field of safety of nuclear power plants and can be used to improve and develop new technologies in this field

Анализ термометрических данных головного мозга, полученных методом микроволновой радиотермометрии

This paper discusses the effectiveness of using the method of microwave radiothermometry in examinations of brain diseases, namely the state of disordered consciousness. In contrast to most methods of examinations by this method, the measurements of the brain were carried out in only 2 different frontal areas for 2 days with a frequency of 4 hours. Therefore, the aim of the study was to identify the effectiveness of a diagnostic model based on the dynamics of temperature changes. The work showed that in healthy patients there is a circadian rhythm: during the day the temperature rises, at night it decreases. At the same time, such dynamics is not observed in patients with disordered consciousness. Based on this knowledge, a conceptual and mathematical model were proposed. The first of them describes the characteristic features of healthy and sick patients. The second one quantifies these features. The constructed mathematical model was tested in the classification problem. The Naive Bayes classifier was used as a classifier. As a result of computational experiments, it was shown that for 500 iterations the classifier made a mistake on only 1 sick patient and 5 healthy ones. Thus, the effectiveness of the method of microwave radiothermometry in the task of examining patients with disordered consciousness was shown.

Denaturation of proteins under the influence of ultrasound. Hypothesis

In the food industry, the use of ultrasound as a non-thermal treatment is expanding. Ultrasound is often used at the final stage of food production to improve rheological characteristics and prolong shelf life. However, an increase in temperature during ultrasonic treatment can negatively affect the quality of the final product. An increase in temperature during food processing causes the denaturation of enzymes. For most enzymes of animal origin, the denaturation temperature is 40-50 °C, and for enzymes of plant origin it is 50-60 °C. At the same time, at a temperature of 80 °C and above, all enzymes are destroyed. In this regard, it was very important to investigate possible temperature changes during ultrasonic treatment. The essence of the hypothesis put forward by “Shoman” is the study of the fact that during ultrasonic treatment, thermal effects occur, at which protein denaturation begins. An increase in the temperature values during ultrasonic treatment above the denaturation temperature of proteins confirms our hypothesis. It is established that: 1) with ultrasonic exposure to a two-component oil/ water emulsion, the temperature rises to 83 °C with a duration of exposure of 28 minutes; 2) an increase in the proportion of oil relative to water contributes to an increase in temperature from 74 to 83 °C; 3) with equal oil/water ratios, the content of mineral salts and organic substances in drinking water contributes to an increase in temperature under ultrasonic exposure compared to distilled water. The results obtained are valid for a two-component water-oil emulsion. It is of interest to study the influence of other food components on the dynamics of temperature changes during ultrasonic treatment. I would like to know the opinion of other researchers on the “Shoman” hypothesis.

The Thermal Influence of an Electromagnetic Field with a Radio Frequency Depending on the Type of Electrode Used.

Diathermy is a method used in physiotherapy based on obtaining an increase in temperature by supplying energy from the electromagnetic field to the tissues. The aim of this retrospective work, based on the data included in a medical documentation, was to assess the dynamics of temperature changes on the body surface after the application of a high-frequency electromagnetic field depending on the type of electrode used. In order to generate a radio frequency electromagnetic field, an INDIBA ACTIV® CT9 was used. In order to measure the temperature, an HT-17 thermovision camera was used, enabling measurements within the range of −20 to 300 °C, with an accuracy of ±2% or 2 °C. The participants consisted of 30 healthy subjects (15 women and 15 men) who were physiotherapy students in the Faculty of Public Health in the Silesian Medical University in Katowice, Poland; they were divided into two comparative groups (A and B). It was found that the differences between the groups were not significant in the measurements carried out before using the electrode (p = 0.84; Mann–Whitney U test). On the other hand, at 0, 5 and 15 min, statistically significant differences were noted in the tissue temperature between the groups, depending on the electrode used (p = 0.00; Mann–Whitney U test). Based on the obtained results, it can be concluded that with the extension of the observation time, the tissue temperature increased (for Group A, Me 30.40 °C vs. 34.90 °C; for Group B, Me 30.70 °C vs. 35.20 °C). Our study confirmed that the use of both a capacitive and resistive electrode during treatment with the use of a high-frequency electromagnetic field statistically significantly increased the surface temperature of the area to which the therapy was applied. The results of the study can be used in clinical practice by physiotherapists to optimize the conditions of therapy.

Experimental investigation of energy consumption for the process of initial heating of a substrate for the use of electric heat-mechanical system

Purpose. Experimental determination of energy consumption for the process of initial heating of the substrate to the temperature of anaerobic digestion in a biogas reactor using an electrothermal-mechanical system with automatic control to assess the energy efficiency of the process of heating the substrate and the profitability of further processing of the resulting biogas into thermal and electrical energy.
 Methodology. Experimental studies of the dynamics of temperature changes in an heating cable placed in an electrothermal-mechanical system, determining the duration of the process and the energy consumed by the initial heating of the substrate, processing and analysis of the obtained data arrays, summarizing the results obtained.
 Findings. Biogas technologies play an important role in the formation of a modern energy system, the profitability of which directly depends on the energy efficiency of anaerobic digestion intensification. The process of digestion of waste is long, so one of the main methods of intensification of biogas production is the mixing of waste in the process of anaerobic fermentation. There is a need to improve the energy efficiency of anaerobic digestion intensification and the profitability processing of biogas into heat and electricity. Ways to improve energy efficiency mainly consist in reducing the time of heating the substrate in a biogas reactor, reducing the consumption of electrical energy for the process of thermal stabilization of anaerobic digestion, structural combination of energy-efficient systems for mixing and heating raw materials in reactors, and introducing automatic production systems. The implementation of these actions will make it possible to establish the optimal geometric dimensions of an electrothermal-mechanical system with automatic control for mixing and heating the substrate in a biogas reactor and significantly increase the energy efficiency of biogas plants and the subsequent processing of the resulting biogas into thermal and electrical energy.
 Originality. As a result of the experimental study and analysis of the data obtained, it was found that with the same power of the heating sections, the change in the temperature of the electric cable in each blade does not occur in the same way. The authors found that the average value of the temperature of the sections of the electric heating cable of the lower blades is 12.9% higher compared to the upper blades of the electrothermal-mechanical system. In the course of experimental studies, the authors found that when using a heating system made of an electric heating cable mounted in the blades of a two-tier paddle mixer, it consumes J, on the process of initial heating of the substrate from before °С in a biogas reactor with a volume of 40 liters. The duration of the heating itself is 300 minutes. In the course of experimental studies, the authors established the energy efficiency from dividing the electrothermal-mechanical system into heating sections, when each blade is a separate section with its own automatic temperature control of the electric heating cable mounted in the corresponding section, while the consumption of electrical energy is reduced by 27.9%.
 Practical value. The results obtained can be used in the design, construction and modernization of biogas production intensification systems, namely, mixing and heating of the substrate in biogas plants. This will improve the energy efficiency of the biogas formation process and the profitability of its processing into heat and electricity.

ДЕЯКІ ПИТАННЯ ВИЯВЛЕННЯ СТАДІЙ РОЗВИТКУ ШАХТНИХ ПОЖЕЖ

Purpose. Consideration and analysis of the methodology for detecting fires occurring in coal mines in order to establish the main issues of temperature assessment and the stages of an extinguished fire. Methodology. The research methodology consists of analysing the methodology for detecting the stages of development and attenuation of endogenous and exogenous mine fires, as well as assessing their similarities and differences. Using the data obtained as a result of research, we consider the possible temperature in the source of a mine fire, its change in the process of burning and attenuation of the fire. A new approach to assessing the state of a fire is proposed in the form of a temperature-heat-conducting method for assessing its state and other solutions. Results. The main features of underground fire detection are the large length, branching of underground workings and the complexity of the ventilation system. Also, such physical parameters of the air jet are taken into account that are associated with heat and mass transfer (flow velocity, the magnitude of the temperature field, gas concentrations and the general composition of the gaseous medium) and not associated with heat and mass transfer (spectral characteristics, air density (or transparency), electromagnetic characteristics). Physical features are of the greatest interest from the point of view of detecting an underground fire. The most effective additional emergency criteria for early detection of an underground fire are the rate of increase in air temperature and the rate of increase in the concentration of carbon monoxide. The paper substantiates a method for assessing the state of a fire in a mine based on the dynamics of temperature increase in its source. After the write-off of the fire, reconnaissance of mine workings in an insulating fire area, control observations of the gas composition of the air and the absence of signs of spontaneous combustion of coal, the jumpers are dismantled and installation and restoration work is carried out according to a specially developed project. Scientific novelty. It has been established that the main stage of development of a mine fire can be most correctly established by the dynamics of temperature changes, the method of such an assessment is substantiated. Practical significance. The research results will be necessary to develop a method for establishing the main stage of development and attenuation of a mine fire.

AUTOMATION OF TECHNOLOGICAL PROCESSING OF PRODUCTS MADE OF PHOTOPOLYMER MATERIALS

The use of new modern structural materials that would improve the physical and mechanical properties of products, aggregates and components of agricultural machines will help to reduce the mass fraction of metals in their design. It was determined that the use of additive technologies in mechanical engineering is hindered by poor product quality due to the lack of automated control of the polymerization process in the production of 3D products. (Research purpose) The research purpose is developing an algorithm to the process of automated control of the technology of manufacturing products from photopolymers. (Materials and methods) A set of controlled parameters of the photopolymerization process was substantiated in the manufacture of parts using additive technologies, which were taken as polymerization time and the dynamics of temperature changes in the material. (Results and discussion) The results of the use of an automated photopolymerization process were given and its analysis was carried out on the example of a typical technological process for obtaining samples of polymer composites similar to natural organic materials. Thermal phenomena that occur when exposed to ultraviolet radiation during polymerization are described. We carried out experimental and industrial tests of the physical and mechanical properties of basic photopolymer resins, which in practice allowed us to investigate the operation of the algorithm of the process control system and conclude that all the indicators of the tested samples exceed in quality the values of samples from acrylic plastics made by the traditional method. (Conclusions) We have developed an algorithm for an automated system of extreme control of technological processes of manufacturing products using additive technologies using photopolymers and their composites. The beginning and end of the polymerization process were identified automatically, increasing the mechanical characteristics of the products. It has been shown that in the production of machine-building parts and, in particular, agricultural engineering, it is possible to use additive technologies.

Automated Method for Controlling Oil Filling of Polymer and Composite Materials

For the modernization of polymer and composite materials in order to increase their operational properties, namely strength and wear resistance, there are created oil-filled polymer and composite materials. Filling the manufactured part with oil is problematic in the automating the control of the filled state. The filling process is applicable for polymer or composite bearing separators of agricultural machines (forage harvesters, cotton harvesters, grape harvesters and others) in order to increase their service life in conditions of a large amount of dust and dirt, as well as in cases of dry start. (Research purpose) The research purpose is in developing a methodology for automated filling control of structural polymers and composites used in agricultural machinery with antifriction materials. (Materials and methods) The article presents designed and produced experimental installation and field tests. The developed sensor placement scheme allows performing experimental studies on measuring the volumetric body temperature of a polymer or composite sample during the impregnation process online. The differentiation of the obtained results, presented in graphical form, makes it possible to quickly analyze the dynamics of temperature changes in the thickness of the material. (Results and discussion) The article presents the optimal proportion of a mixture of hexane and M-8B engine oil and the most favorable temperature conditions. It was confirmed the possibility of using this technique in the technology of oil filling of antifriction products made of polymer and composite materials. (Conclusions) The technique makes it possible to identify the filled state of manufactured polymer or composite parts used in friction units of agricultural machines without the introduction of thermal sensors. The control is carried out according to the previously obtained values of the speed and time of impregnation to a given depth of penetration of the oil filler, depending on the type of material.

Automated control of the production process of antifriction polymer materials

This paper presents a technique of controlling the process of oil filling of polymer and composite materials, which allows automated determination of volumetric heating of a polymer or composite sample for the purpose of drying. The differentiation of the obtained results, presented in graphical form, made it possible to quickly analyze the dynamics of temperature changes in the thickness of the material, the change of which determines the rates and time of impregnation to a certain depth of the body of the polymer or composite sample in figure 1. According to the developed methodology, studies of the impregnation of the oil filler of a mixture of M8-B motor oil and hexane were carried out. For each experiment, time dependences of the impregnation rate were obtained. Based on the work carried out, the optimal proportion of a mixture of hexane and engine oil and the most favourable temperature conditions were determined. At the end of the research, the assumption about the possibility of using this technique for the purpose of its industrial use in the technology of oil filling of antifriction products made of polymer and composite materials was confirmed.

Dynamics of temperature change during experimental respiratory virus challenge: Relationships with symptoms, stress hormones, and inflammation

Thermoregulation is a complex, dynamic process involving coordination between multiple autonomic, endocrine, and behavioral mechanisms. In the context of infection, this intricate machinery generates fever, a process believed to serve vital functions in the body's defense against pathogens. In addition to increasing core temperature, infection can lead to changes in the dynamic fluctuations in body temperature over time. The patterns of these deviations may convey information about the health of the body and the course of illness. Here, we utilized dynamic structural equation modeling to explore patterns of body temperature change following an experimental respiratory virus challenge in an aggregated, archival dataset of human participants (N = 1,412). We also examined whether temperature dynamics during infection were related to symptom severity, as well as individual differences in biomarkers of inflammation and stress. We found that individuals meeting the criteria for infection exhibited higher but less stable body temperatures over time compared to those not meeting criteria of infection. While temperature parameters did not reliably predict symptom severity, higher levels of nasal proinflammatory cytokines were associated with lower, more consistent temperatures during the study period. Further, levels of salivary cortisol and urinary catecholamines measured at the beginning of the study appeared to have disparate effects on temperature change. In sum, this research highlights the utility of dynamic time series modeling as a framework for studying body temperature change and lends novel insights into how stress may interact with infection to influence patterns of thermoregulation.

SIMULATION OF OPERATION OF THE AUTOMATED SYSTEM OF LOCAL MULTI-CIRCUIT COOLING OF PARTS OF AUTOTRACTOR DIESEL ENGINE

The results present the intermediate stage of the study of the thermal state of individual heat-stressed parts and units of a forced tractor diesel engine in the conditions of their local air cooling (LAC), which is regulated in automatic mode. Possibilities of practical implementation on the basis of microprocessor control systems of multi-circuit local cooling of parts of valve exhaust unit, bearing unit of turbocharger, if necessary, additional air cooling of the upper part of cylinder blocks in the area of cylinder liners are considered and evaluated. The listed parts, as evidenced by the results of many engine tests, differing in the values of the maximum critical temperatures, which in turn depend on the course of heat exchange processes in the corresponding interfaces, nodes. At the same time, in the conditions of operation with the use of the LAC system on the diesel engine there are additional problems associated with the complication of the cooling control algorithm, the need to move to multi-circuit options with their critical temperature values and required cooling air costs. At this stage of the study, a test was performed in the test mode of the algorithm for supply control and shutdown of the coolant supply, the corresponding circuit solutions for its implementation. In the engineless experiment, previously specially designed and thermocoupled units were used, which were heated separately with the set test temperatures, as well as a series-produced unit, which is part of the 4th generation gas cylinder equipment (GCE) of modern engines. The unit consists of four sections with solenoid valves, which dose the gas supply to the injectors according to a given algorithm (Valtek type 30). At the input of the engineless experiment, this unit was used to turn on and off the supply of compressed cooling air in separate circuits (from 2 to 4). The moments of operation of the valves (opening-closing) corresponded to the set test temperatures. In addition to the dynamics of temperature changes at the control points of the research units during the cooling process, the pressure, temperature, and coolant flow rates on individual circuits were also monitored. The conducted engineless experiment confirmed the correctness of the adopted circuit solutions, and also proves the possibility of further application of serial GCE units in LAC systems.

Detection and Model of Thermal Traces Left after Aggressive Behavior of Laboratory Rodents

Automation of complex social behavior analysis of experimental animals would allow for faster, more accurate and reliable research results in many biological, pharmacological, and medical fields. However, there are behaviors that are not only difficult to detect for the computer, but also for the human observer. Here, we present an analysis of the method for identifying aggressive behavior in thermal images by detecting traces of saliva left on the animals’ fur after a bite, nape attack, or grooming. We have checked the detection capabilities using simulations of social test conditions inspired by real observations and measurements. Detection of simulated traces different in size and temperature on single original frame revealed the dependence of the parameters of commonly used corner detectors (R score, ranking) on the parameters of the traces. We have also simulated temperature of saliva changes in time and proved that the detection time does not affect the correctness of the approximation of the observed process. Furthermore, tracking the dynamics of temperature changes of these traces allows to conclude about the exact moment of the aggressive action. In conclusion, the proposed algorithm together with thermal imaging provides additional data necessary to automate the analysis of social behavior in rodents.

Assessment of the Dynamics of Temperature Changes in the Knee Joint Area in Response to Selected Cooling Agents in Thermographic Tests.

Although local cryotherapy (LC) is performed with various cooling agents (CAg) such as ice, water, and gasses, in clinical practice, it is mostly performed with cooling gasses. Presently, LC with cooling gasses is very popular but the inference about the thermal (stimulus) effect on the tissues is mainly based on research carried out using ice packs. The proposed objective of the study was to evaluate the dynamics of temperature changes in the knee joint area in response to a 3-min exposure to liquid nitrogen vapors (LNVs), cold air (CA) and ice bag (IB). The study group included 23 healthy volunteers with an average age of 26.67 ± 4.56. The exposed (ROIE) and contralateral (ROINE) areas of the knee joint after exposure to CAg were observed. Immediately after 3 min of LC, the ROIE temperature dropped by 10.11 ± 0.91 °C after LNV, 7.59 ± 0.14 °C after IB and 6.76 ± 1.3 °C after CA. Significant tissue cooling was maintained up to 15 min after LNV (p < 0.01), 10 min after IB (p < 0.05) and 5 min after CA (p < 0.05). LC causes significant temperature changes both in ROIE and ROINE. The greatest cooling potential was demonstrated for LNV and the lowest for CA.

ОПЕРАТИВНЫЙ МОНИТОРИНГ И УПРАВЛЕНИЕ ТЕМПЕРАТУРНЫМИ РЕЖИМАМИ РЕСУРСНОЗНАЧИМЫХ АГРЕГАТОВ АВТОТРАКТОРНОЙ ТЕХНИКИ

When operating automotive equipment at low or high ambient temperatures, various devices are required to maintain the thermal regime of the units in the permissible range, which significantly affect the internal energy consumption and the service life of the machine. Currently, such a complex thermal preparation is implemented only for the engine by heating or cooling the coolant. For other systems and units, continuous monitoring of their temperature is not provided, and there are no rules or clear requirements for the implementation of such heat preparation. (Research purpose) The research purpose is in expanding the functionality of remote diagnostics by operational monitoring and control of the temperature conditions of individual machine units. (Materials and methods) Authors used research methods based on the application of standard techniques, the object of research was the system of integrated thermal automotive equipment. In addition to heating the engine before starting, other systems and units need to optimize the thermal regime, most of which can be combined into a comprehensive heat treatment system. (Results and discussion) As a result of experimental studies of the integrated heat treatment system mounted on a KAMAZ vehicle, the dynamics of temperature changes in various units during their heat treatment were and presented. Monitoring and controlling the temperature regime of automotive equipment units will reduce internal power losses and increase the service life of units exposed to temperature. (Conclusions) The introduction of a comprehensive heat treatment system, intelligently and functionally linked to a remote monitoring system, will significantly increase the service life of the units most exposed to temperature influences.

Analysis of the microflora of dried grape fruit products

The article presents an analysis of the microflora of dried grapes with a description of the factors of influence. A technological method of processing dried grapes using ultrasonic action on plant raw materials is described. The fruits of dried grapes were investigated using different methods of pre-preparation - preliminary hydration of the fruits within 24 hours at a temperature of 20 ± 2 ° C. The dynamics of temperature changes during the processing of plant raw materials is analyzed. The indicators of microbiological safety of the products obtained from dried grapes were investigated. An analysis of the risk situation associated with the safety performance of ultrasonic treatment using the Fault Tree Analysis (FTA) method is presented. Situations that can lead to the occurrence of events in the production of products from dried grapes using technology based on the principles of ultrasonic exposure are analyzed.

Study of the influence of temperature on the parameters of natural fuel gas

Differences in normative documents on the definition of "standard conditions" and parameters at which the heat of combustion of natural gas is determined are analyzed. When determining the energy value of natural gas in European countries, different values of the final temperature of combustion products, values of higher or lower heat of combustion are used. This causes a deviation of up to 19 % of the values of the heat of combustion of natural gas of the same composition, depending on the standard conditions established in a particular country. The dynamics of temperature change in some sections of the network and its influence on the determination of gas volumes were studied on the example of the urban-type settlement of Yampil, Khmelnytsky region. On the basis of actual values of the basic gas parameters in characteristic pointss of the settlement network, influence of ambient temperature on the basic parameters of the gas is investigated. Graphical dependences of gas density, Wobbe index, and gas volume on temperature are constructed. Based on the calculations, it was determined that when the temperature changes in the range from 0 to 40 °C, the volume of gas increases by 0.34 m3 per 1 °C. The density decreases by 0.002 kg/m3 per 1 °C. The maximum value of the Wobbe index is reached at temperatures of 10 and 25 °C. The same volume of gas can have different energy value, as it directly depends on the composition and percentage of the components of the gas mixture. There are special metters, which analyze the gas components. But they are installed only at large consumers. The presence of a corrector for temperature and pressure at the gas metering unit allows to increase the reliability of metering, but does not completely solves the problem. The amount of gas measured by the meters must be brought to standard conditions and converted into units of energy.

METHOD FOR STUDYING THE INFLUENCE OF THERMAL INERTIA ON THE ROOM TEMPERATURE

The efficiency of using thermal energy that is received from the central heating system to supply a building (a complex of interconnected rooms) is determined by the completeness of information available on the factors that affect the thermal regime. This article presents an approach that allows evaluating the significance for thermal management of such complex parameters as thermal inertia of a room and features of its use. The proposed methodology is based on the analysis of the dynamics of temperature changes in rooms, considering the standard characteristics that determine heat exchange, meteorological conditions, and the presence of people. The degree of the thermal inertia influence on a room is determined on the lag time, which is the time interval between a significant change in weather conditions or the supply of thermal energy and a change in the air temperature in the room. The initial data included the values of the temperature of the air and heating elements, that were obtained from the sensors located in a university building. The observation was conducted between 1 March and 19 April 2020 (measurement frequency — 10 minutes). The collected data consist of measurements gathered during room usage in different modes. Additionally, the presence of periods of complete shutdown of the heating system also affected the respective data. The module of the intelligent monitoring system for the thermal regime of the building was developed to perform data analysis. The module was implemented as a pipeline that sequentially performs the following operations: filtering and cleaning data; aggregation for specified periods; determination of the delay time. The results of the data analysis show the possibility of selecting groups of rooms that react to significant changes in external conditions and heating mode with a remarkable lag time. This confirms the importance of considering the thermal inertia for efficient heating control (intermittent operation). The results allow concluding that it is possible to build a classification model based on the thermal inertia parameter. These models will help in determining the most significant factors affecting the thermal regime of the room. In its turn, it allows producing recommendations for making decisions on heat supply management.

ОПЕРАТИВНЫЙ МОНИТОРИНГ И УПРАВЛЕНИЕ ТЕМПЕРАТУРНЫМИ РЕЖИМАМИ РЕСУРСНОЗНАЧИМЫХ АГРЕГАТОВ АВТОТРАКТОРНОЙ ТЕХНИКИ

When operating automotive equipment at low or high ambient temperatures, various devices are required to maintain the thermal regime of the units in the permissible range, which significantly affect the internal energy consumption and the service life of the machine. Currently, such a complex thermal preparation is implemented only for the engine by heating or cooling the coolant. For other systems and units, continuous monitoring of their temperature is not provided, and there are no rules or clear requirements for the implementation of such heat preparation. (Research purpose) The research purpose is in expanding the functionality of remote diagnostics by operational monitoring and control of the temperature conditions of individual machine units. (Materials and methods) Authors used research methods based on the application of standard techniques, the object of research was the system of integrated thermal automotive equipment. In addition to heating the engine before starting, other systems and units need to optimize the thermal regime, most of which can be combined into a comprehensive heat treatment system. (Results and discussion) As a result of experimental studies of the integrated heat treatment system mounted on a KAMAZ vehicle, the dynamics of temperature changes in various units during their heat treatment were and presented. Monitoring and controlling the temperature regime of automotive equipment units will reduce internal power losses and increase the service life of units exposed to temperature. (Conclusions) The introduction of a comprehensive heat treatment system, intelligently and functionally linked to a remote monitoring system, will significantly increase the service life of the units most exposed to temperature influences.

Радиометрический метод контроля токов утечки в диэлектриках

A new experimental method for leakage current (conduction current) measurements in dielectrics, based on an analysis of the dynamics of temperature changes of the sample under the action of an electric field is proposed. A new non-contact photodiode IR-temperature sensor carries out high accuracy and high speed monitoring of the sample temperature response. The capabilities of the method are demonstrated on samples of 0.65 PbFe2/3W1/3O3-0.35 PbTiO3 (PFW-PT) ceramic, for which the experimental dependence of conductivity was obtained in a wide temperature range from 20 to 110 ° C.