Supply Mode Research Articles

AI 기술이 제공하는 서비스와 서비스 무역 규범에 대한 논의

Regarding whether GATS applies to services provided by AI technology, Article 1.1 of GATS declares that this Agreement applies to measures of Members affecting trade in services, focusing on “measures.” Since GATS applies to all trade in services regardless of the means of supplying services, supplying services electronically falls within the scope of GATS. In addition, GATS does not have provisions distinguishing between various technological means of supplying services, so services provided by AI technology are also included within the scope of GATS. AI is essentially software, and software is a service, so AI falls under the “Computer and Related Services” sector under the 1991 W/120 classification. Under the current CPC Version 3.0, AI will be specified under the subsector “Application software provision” and “On-line software”. GATS prepared its service concessions under the 1991 W/120 classification, and this classification has been aligned with the corresponding CPC classification numbers. Since this classification document was prepared in 1991, once the CPC Version 3.0 revision work is complete, the classification document will need to be revised to align with the new CPC classification numbers. Service-driven AI technology are imported when purchasing subscriptions from foreign-owned or foreign-based LLMs providers, and then a service trade occurs. Purchasing data labeling or data annotation services from foreign-owned or foreign-founded companies is also importing services. This type of service trade is likely to occur through Mode 1 among the service supply modes. On the other hand, when AI technology is installed in a product, such as a self-driving car, and the product is imported, and the product exists in the country where the consumer resides and provides the service, the product and the service are provided and consumed simultaneously, and the product acts as a kind of “service provider” at the moment the consumer consumes the service, which may differ from the WTO’s regulatory system. Therefore, there have been attempts to recognize the form of service trade included or embodied in a product as Mode 5, and to recognize it as a new supply of service in GATS, but it has not been formally discussed at the WTO level. The trade method in the form of Mode 5 is similar to Mode 1, which is the cross-border supply of services, so service trade is treated as Mode 1, and when services are integrated with products and trade occurs, the service no longer exists and the GATT, which is the rule applied to products, is applied.

Enhancing heat and moisture transfer of porous fabrics using arrayed opposed jets: Experimental and numerical investigations

Achieving rapid fabric drying and ensuring a uniform distribution of surface temperature and moisture is essential for the post-processing stage in printing and dyeing. Although jet technology is commonly used to enhance heat transfer processes, the mechanism of heat and moisture transfer using array opposed jet for fabric drying is still unclear. This paper proposes that using opposed jet to enhance the drying process for four different fabric structural types, the influence of jet Reynolds number and excess temperature on the change of fabric moisture content was analyzed using experimental methods, then by defining the fabric as a porous medium containing two-phase components, the flow characteristics and temperature field distribution of the opposed jet were obtained using numerical methods. The results indicated that the four different structural types of fabrics exhibited similar heat-moisture transfer characteristics under the air supply mode of the opposed jet. Furthermore, the critical evaporation temperature of fabrics with hygroscopic properties was higher than that of non-hygroscopic fabrics. When the Reynolds number increased from 649.4 to 2165.3 and the excess temperature increased from 40 ℃ to 70 ℃, the drying time was shortened by a maximum of 56.2 % and 25.5 %, respectively. Under the impact of the array opposed jet, the thermal boundary layer on the fabric surface was thinned, and the local Nusselt number presented different peaks along the length direction of the impinging surface. Within the range of operating conditions considered, at a jet wind speed of 4.5 m/s and an excess temperature of 70 ℃, the maximum surface drying rate of the fabric was achieved. The relative deviations of heat flux and mass flux on the impact surface are all within 10 %. This study provides a theoretical basis for the structural design and drying mechanism exploration of fabric drying equipment.

STUDY OF LOADER TRANSMISSION DYNAMICS WITH HIGH TORQUE STEP-ADJUSTABLE HYDROMOTOR-WHEELS

Goal. The purpose of the article is to analyze the dynamics of the hydraulic fluid power of the forklift transmission equipped with radial-piston high- torque multi-cycle hydraulic motors with a step change in working volume. Such a transmission is offered as a gearless one compared to the use of traditional transmissions with axial-piston hydraulic motors and gearboxes in front of the drive wheel hub. Research methodology. The traction-speed characteristic of a serial wheel loader is built taking into account the constant power of the drive internal combustion engine for rotation of the axial- piston reversible adjustable transmission pump. The dependence of the torque on the wheel hub of the loader depending on its speed was analyzed. The selection of a high-torque radial-piston hydraulic motor of multi-cycle action, which satisfies the parameters of the transmission in terms of torque and maximum rotation frequency and does not have an intermediate gearbox on the hub, has been made. To reduce the set power of the drive motor of the loader pump and fuel consumption, the hydraulic motors of the transmission are also equipped with a two-stage regulator for changing the working volume. Constructed block diagrams in the VisSim application program package for the solution of nonlinear differential equations for determining the speed of the loader, the pressure in the hydraulic drive and its useful power. The results. The analysis of oscillograms of dynamic processes in the hydraulic drive of the loader showed that by means of modeling the pump supply modes and step change of the working volume of the multi-cycle radial piston hydraulic motor, it is possible to detect extreme modes that lead to fluctuations in the speed and power of the loader, as well as pressure in the hydraulic drive.

Prediction of SO2 concentration in WFGD system based on GWO optimized CNN‐BiLSTM‐attention

AbstractDue to external disturbances, the parameters of the desulphurization system are uncertain, and their relationships are complex, which makes it difficult to predict the concentration of SO2 at the desulphurization system outlet. In this paper, grey wolf optimization (GWO) optimized convolutional neural network (CNN)‐bi‐directional long short‐term memory (BiLSTM)‐Attention algorithm was used for prediction, and the problem of low SO2 concentration prediction accuracy at outlet has been resolved. First, the outliers of the thermal power plant desulphurization data were processed using the local outlier factor (LOF) algorithm. Secondly, CNN‐BiLSTM model was constructed using CNN and BiLSTM, and attention module was added to realize feature extraction and better capture the regularity of input data. Then, the CNN‐BiLSTM‐Attention model was optimized using GWO and its hyperparameters were improved. Finally, based on the Matlab R2023a platform, the prediction comparison as well as the error analysis of the desulphurization data were carried out. In the prediction of SO2 concentration in low‐flow continuous slurry supply mode, the error of the combined model decreased by 23.2% on average compared to the CNN‐BiLSTM‐Attention model. In the prediction of SO2 concentration in the high‐flow intermittent slurry supply mode, the error of the combined model decreased by 20.8% on average. According to the results, the combined model surpasses both the single model and several other algorithmic combination models in terms of performance metrics, and the predictions are more accurate.

Cooperative Production: Research on the Supply Mode of Urban Elderly Care Catering Service

Cooperative Production: Research on the Supply Mode of Urban Elderly Care Catering Service

A study on the scaled intelligent supply mode of biomass briquette fuel in China

In the backdrop of China's ‘Carbon peak, Carbon neutrality’ goal, to reduce the pollution caused by carbon emissions to the atmosphere, this study investigates the supply of biomass briquette fuel. The supply of biomass briquette fuel is generally divided into two stages: the first stage involves the collection, storage, and transportation of biomass straw to the biomass briquette production base; the second encompasses the processing of the biomass straw into briquette fuel at the production base, followed by its transportation to the biomass boiler heating center for utilization. In this paper, a mathematical model is developed based on carbon emission and economic cost. The model is then calculated with an optimized intelligent algorithm, and the results are subjected to sensitivity analysis. The results demonstrate that: (1) Compared to the pre-optimization phase, the optimized model increases profits by 26.31 % and reduces carbon emissions by 12.64 %. (2) The adaptive genetic algorithm shows significantly better convergence speed and accuracy compared to the traditional genetic algorithm, making it more suitable for intelligent calculations of biomass briquette fuel supply. (3) As the weight coefficient of carbon emissions increases, economic costs continue to decrease with increasing sensitivity, while carbon emissions continue to decrease with decreasing sensitivity. These results provide references for further optimizing the weight coefficients of economic costs and carbon emissions in the supply of briquette fuel. This study contributes to reducing carbon emissions and provide references for the rational and intelligent supply of biomass briquette fuel.

Influence of the Building’s Thermal Insulation on Intermittent Heating Mode Efficiency

Abstract The results of mathematical modeling of a building’s thermal insulation influence on the efficiency of intermittent heating mode are presented. This work aim is to assess the influence of thermal insulation on the efficiency of using the intermittent heating mode for the educational building of the Odessa National Polytechnic University’s Heat Engineering Laboratory. The paper analyzes the factors related to improving the efficiency of the programmed heat supply mode. Modeling of the operating modes for heat supply system operated in intermittent heating mode is carried out. There was performed the mathematical modeling of the heating system operation modes for the most unfavorable climatic conditions at low outdoor temperatures, with respective system efficiency indicators obtaining. The potential of energy saving level for administrative, educational, and office buildings depending on the thickness of thermal insulation of external and internal walls is studied. Recommendations have been elaborated for the use of buildings thermal insulation to improve the efficiency of intermittent heating.

Modeling EV dynamic wireless charging loads and constructing risk constrained operating strategy for associated distribution systems

Dynamic wireless charging (DWC) is an emerging technology that enables the charging of electric vehicles (EVs) while they are in motion. However, previous load modeling methods have not thoroughly explored the detailed analysis of DWC load characteristics. Existing research only considers the single-node supply mode for dynamic wireless charging roads (DWCRs), and the assessment of operational risks arising from the uncertain DWC loads has not been addressed. This paper begins by conducting an equivalent circuit analysis of a typical EV DWC system with multiple segmented coils. We present a more accurate trapezoidal power model for a single EV. Subsequently, we model the aggregated EV DWC load, accounting for traffic flow and headway using Poisson and negative exponential distribution functions, respectively. In the operation process, we consider a multi-node supply mode for DWCRs. To address the inaccuracy of long-term predictions, we propose a rolling optimization model to coordinate DWC and renewables with heterogeneous uncertainties by introducing a risk metric to manage potential uncertain risks. The proposed optimization model is transformed into a mixed-integer second-order cone programming (MISOCP) problem after convex relaxation. Finally, we conduct case studies to validate the proposed methods.

Three-Stage Solid-State Fermentation Technology for Distillers’ Grain Feed Protein Based on Different Microorganisms Considering Oxygen Requirements

The shortage of feed protein has plagued the development of the animal husbandry industry in China. In this study, a new three-stage fermentation technology for producing distillers’ grain feed protein was developed by introducing Aspergillus niger, yeast, and lactic acid bacteria. During the aerobic stage, there was a negative correlation between the reducing sugar content in the distillers’ grains and the amount of Aspergillus niger. The maximum reducing sugar concentration (36.89 mg g−1) was obtained when the oxygen supply was 30 mL min−1 and the fermentation time was two days. During the microaerophilic stage, the natural exchange of oxygen achieved optimal true protein enhancement (from 10.8% to 16.4%) among the three oxygen supply modes (natural exchange, forced ventilation, and filling supplement). During the anaerobic stage, lactic acid bacteria were inoculated for feed protein preservation and flavor enhancement. Our results provided insight and practical guidance for the high-value use of distillers’ grains.

Comprehensive analysis of thermal performance and low-grade energy charging efficiency of pipe-embedded building envelopes enhanced with single-level tree-shaped fin structures

Pipe-embedded walls (CnPWs) are structural and energy composite building components that can resist external disturbances by forming stealth thermal shielding layers. To tackle the mismatch between the heat charging rate and heat diffusion rate during energy charging processes, as well as the unsatisfactory robustness of stealth thermal shielding layers, the single-level tree-shaped metal finnd pipe-embedded walls (TfPWs) are proposed. To verify the effectiveness of TfPWs and obtain dynamic performances, a simulation study is conducted on 8 risk variables in 4 pairs through the validated numerical model. Results showed that the improved design was effective in obtaining more robust thermal shielding layers in auxiliary energy supply mode, the effect gained prominence as both the injection temperature and pipe spacing were augmented. In room heat load reduction mode, favorable benefits arise when pipe spacing exceeds 400 mm. The maximum increase rate of total injected energy under different reduction ratios of external insulation layer was 11.83%–31.91 %, while the maximum extra total heat loss was 5.33 %. Secondly, the trunk fins and branch fins played different roles in minimizing the excessive heat accumulation surrounding pipes, and the vertical and horizontal sizes of heat accumulation region mainly increased with the increase in trunk fin size and branch fin size respectively. Meanwhile, the utilization efficiency of fin material was higher when trunk fin size was smaller, and parameter combinations with trunk fin size of 0.2b and branch fin size of 0.4a/0.6a could achieve a better balance between material input and performance increase. Thirdly, the improvement effect of single left branch fin schemes was close to that of double branch fin schemes and significantly better than that of single right branch fin schemes. It was recommended to use single left branch fin schemes with an inclination angle of 60°. Finally, even if the reduction ratio of external insulation layer in different cities increased to 80 %, the inside surface temperature of TfPWs was still greater than room air. Taking CnPWs with standard external insulation layer as references, the TfPWs applied in Harbin, Beijing, and Shanghai could achieve similar or better results even when the reduction ratio of external insulation layer increased to 60 %, while TfPWs applied in Guangzhou could exhibit better performance even when the reduction ratio of external insulation layer increases to 80 %.

Research on a novel method of air distribution to create a uniform indoor environment in a long and narrow building

Because people work a long time in buildings, good indoor thermal environments and air distributions have attracted increased amounts of attention. To improve the indoor thermal environment and air quality, an effective ventilation strategy must be used. In the air conditioning of a building, the air distribution has been identified as a significant factor that affects the indoor thermal environment. A novel method for air distribution was presented to create a uniform indoor environment along the room length direction. In this study, numerical simulations were carried out to analyse the airflow pattern and performance of the sidewall air supply (SAS) and the sidewall air supply with deflector (SASD). Orthogonal experiments were conducted to study the airflow distribution law of the deflector. The ventilation performance of the two air supply modes was evaluated by air velocity distribution, temperature distribution, horizontal temperature difference, age of air, and other evaluation indicators. The results indicate that the horizontal air temperature differences in the SASD at three heights are 46.05%, 16.44%, and 26.51% lower than those in the SAS, which has a better energy-saving effect. Moreover, the indoor air distribution performance was obtained under three influencing factors: the gap width from the deflector to the ceiling, the horizontal position, and the length of the deflector. A better deflector optimization scheme was obtained. Experimental research was carried out to verify the indoor air distribution of the SASD. This research can provide a reference for the innovative design of indoor air supply systems.

Research on Regulation Method of Variable-Air-Volume Air Conditioning System with “Personal Space”

In large public facilities, such as airport terminals or open-plan office spaces, the HVAC system typically consumes substantial amounts of energy. However, individuals often gather at specific areas while other zones are occupied by transient or occasional users. To minimize operational energy usage, this paper aims to reduce thermal comfort demands in non-targeted areas. This paper introduces a method for regulating the thermal environment around occupants exclusively in the variable-air-volume (VAV) air conditioning running mode. The investigation utilizes Airpak modeling and experimental verification techniques. Additionally, an analysis of temperature field and velocity field distributions within the room under the “personal space” operation mode is presented. The results suggest that adjusting the numbers of air vents, openings, airflow velocities, and air supply orientations can establish a comfortable thermal environment for inhabitants and reduce the overall ADPI value. The combined air supply mode leads to a 16.7% reduction in power usage compared to traditional full-space operation.

Research on mobile energy storage scheduling strategy for emergency power supply protection of post-disaster isolated loads

Aiming at the problem of insufficient power supply capacity of isolated loads in oceanic islands, a concept based on mobile energy storage and power conservation is proposed in this paper. Firstly, the energy flow and traffic flow characteristics of mobile energy storage are quantitatively analyzed, and an accurate mathematical model is established. Furthermore, the time-space distribution characteristics of load are carefully considered, and the Voronoi diagram and Tyson polygon method are introduced to determine cell differentiation. On this basis, combined with the power demand of load nodes and the energy storage characteristics of mobile energy storage vehicles, the evaluation indicators of cell energy and relative surplus energy of cells are designed, and the agent-cellular automata algorithm is used to schedule the mobile energy storage. The simulation results show that the power supply mode based on mobile energy storage can effectively improve the reliability of isolated loads. This paper provides a new perspective for solving the reliable power supply problem of isolated loads.

Восстановление лакового слоя изоляционных пальцев ТЭД с применением установки инфракрасного нагрева камерного типа

Purpose: based on an in-depth analysis of the causes of damage to the insulating fingers of traction motors of electric locomotives, it is necessary to develop a method for increasing their operational reliability. The most effective way to obtain the desired result is to use an improved technology for restoring the electrical insulating varnish layer of insulating fingers using thermoradiation heating. The implementation of a promising technology in depot conditions is possible with the use of a chamber-type infrared heating unit, the control unit of which contains the most optimal energy supply mode determined during experimental studies on a laboratory combined heating unit. Methods: the most significant results of the work were obtained thanks to experimental studies of the electrical and mechanical strength of the cured electrical insulating varnish layer of insulating fingers, in addition, in the process of determining the optimal energy supply mode, finite element modeling methods of thermal processes were used. Results: a design of a laboratory combined infrared heating unit has been developed, thanks to which the optimal drying mode of insulating fingers has been determined, embedded in the operation of an industrial chamber-type unit for drying a set of insulating fingers. Also, the dependence of the breakdown voltage and the hardness of the outer surface of the insulating finger, linking its mechanical and dielectric properties, was determined. Practical significance: the results of the work can be used to improve existing technologies for depot and factory repair of insulating fingers, in particular, to create a series of industrial infrared heating units in locomotive service depots. It is also worth noting that the obtained curve of the dependence of hardness and breakdown voltage, in the future, will allow assessing the electrical strength of insulating fingers indirectly by the hardness parameter of the outer varnish layer.

Optimization Analysis of Water Supply Mode for Fire Protection System of Super High Rise Building

Abstract In order to improve the applicability and reliability of the fire water supply capacity of super high-rise buildings, the fluid analysis software Flomaster was used for simulation. Through the existing pumps, valves, pipelines, pressure reducing valves and newly developed fire hydrants and other components, the fire water supply system of super high-rise buildings is modeled. The pressure distribution of the system pipe network under a given fire water supply mode is studied. The research shows that the simulation can analyze whether there is excessive pressure in the fire hydrant system under different flow conditions in the actual fire extinguishing process. This paper simulates the actual fire extinguishing process of the fire hydrant system through a specific engineering case. The pressure distribution and flow distribution under different flow conditions are obtained. The excessive pressure position of the fire pipe network system under the given fire pump model is obtained. It provides a method for guiding the selection of fire pump and the design of fire hydrant system pipe network. It has certain guiding significance for the subsequent optimization of the design scheme of the fire water supply network and the prediction of the performance of the R&D equipment.

Experimental Model of Cerebral Arterial Air Embolism in Conscious Rats.

In this work, an optimal air supply mode was selected to create a model of cerebral arterial air embolism (CAAE) on conscious male Sprague-Dawley rats (n=49). The efficacy of the selected model (administration of 100 μl/kg of air at a rate of 10 μl/min with an infusion pump) was determined by changes in serum biochemical parameters (cholesterol, alkaline phosphatase, inorganic phosphates, AST, and triglycerides), impaired motor functions in the Rotarod test, and visual assessment of the ischemic foci (staining of frontal sections with 1% triphenyltetrazolium chloride solution) at different terms after AAE. The model of AAE created by us confirmed impairment of coordination and motor function in conscious animals and reproduced the lethal consequences of this condition. The obtained results can serve as the basis for drug testing and the development of new approaches to the treatment of ischemic stroke.

Адаптаційні зміни в організмі студентів із гіпокінезією в процесі реалізації різних моделей занять із силового фітнесу

Topicality. Despite the growing number of fitness programs, health and recreation complexes, innovative recovery systems using a wide range of physical and ergogenic means aimed at restoring the adaptive reserves of students with hypokinesia, there are still no effective ways to solve this problem. The Purpose of the Research. Determine the effectiveness of strength fitness models that differ in content, load parameters, and energy supply modes on the readaptation processes of students with hypokinesia. Methods. 50 students (young men) with hypokinesia (2 groups of 25 people) took part in the research. Students of the 1st group used the strength fitness training model No. 1 developed by us (combination of a complex of strength exercises on simulators with a regime of medium intensity loads in conditions of anaerobic glycolysis). Participants of group 2 used training model No. 2 (using exercises with own body weight with a change in the kinematic characteristics of the performance technique in a combined mode of energy supply (anaerobic and aerobic glycolysis). The methods of control testing of the development of strength capabilities (4 PM) and anthropometry were used. The Results. It was established that the most pronounced increase in strength capabilities (4 PM) ranging from +18,7 % to +26,9 % over 4 months of research was observed in the first group of examined students with hypokinesia. The students of the 2nd research group also showed positive dynamics of the studied indicators, but with a significantly smaller progression (from +8,8 % to +18,7 %). It was investigated that the controlled circumference dimensions of the body show the most pronounced positive dynamics (in the range from +3,9 % to +6,8 % during the research period) among students of the 1st group. At the same time, the representatives of the 2nd group, who during the classes used exercises with their own body weight with a change in the kinematic characteristics of the performance technique in the combined mode of energy supply (anaerobic and aerobic glycolysis), also revealed a positive trend towards an increase in the circumference of the body, but with a significantly smaller progression (from +2,0 % to +3,9 % for the entire period). Conclusions. In the process of research, it was found that it is the combination of a complex of strength exercises on simulators with a regime of medium-intensity loads in conditions of anaerobic glycolysis that allows you to safely use the parameters of the projectile working mass index within 62–65 % of 1 PM for people with a low level of adaptation reserves of the body (hypokinesia), most effectively affects the development of their strength capabilities, hypertrophy of working muscles and readaptation processes.

МОДЕЛИРОВАНИЕ РЕЖИМОВ РАСПРЕДЕЛЕНИЯ ВОДНЫХ РЕСУРСОВ МЕЛИОРАТИВНЫХ СИСТЕМ ДВОЙНОГО РЕГУЛИРОВАНИЯ

The purpose of the research was to develop an algorithm for modeling water supply modes in the control loop "System section" in areas of reclamation systems of dual regulation for further development of software or information tools. The object of research was the pro-cess of water distribution on reclamation systems of dual regulation of the water regime. The information core of the work consisted of provisions on the rules of water distribution on rec-lamation systems and information technologies for automated systems, methods of processing and systematization of information. For modeling, a technique is applied with the allocation of control circuits for which standard modeling tools and algorithms are used. In the course of the research, a simulated water distribution control scheme was compiled on the reclamation systems of dual regulation with a regulating capacity in the control loop «System Section». Modeling functions are defined, such as calculation of water supply modes, modeling of wa-ter intake, transportation and supply modes, calculation of values of regulated levels and their modeling, as well as modeling of water discharge. Based on this and the determination of the initial information for modeling, an algorithm for modeling the distribution of water resources on the reclamation systems of dual regulation site was developed. The task of modeling in this "System section" circuit is to establish the modes of water supply from a regulating tank or a water source receiver by several groups of regulation «A group of water consumers». The de-veloped algorithm includes three stages: preparation for modeling, the modeling of water dis-tribution itself and the maintenance of the results of modeling results

Проблеми відновлення функціональних резервів кваліфікованих спортсменів різних вікових груп у ММА після змагальної діяльності

Topicality. Taking into account the complexity of competitive activities in MMA, the question of determining clear time limits necessary for the complete recovery of the body of individuals of different age groups, using modern methods of assessing the adaptation reserves of the body, cause conflicting views among researchers regarding the effective mechanisms of their implementation. The Purpose of the Research. To determine the effectiveness of recovery of functional reserves of qualified athletes of different age groups in MMA after competitive activity. Methods. 40 qualified MMA athletes (young men) of different age groups (14–16 and 17–18 years) participated in the research. The research was conducted after the performance of the examined athletes at two high-level tournaments, which were held with an interval of 2 days. 4 groups were formed. Representatives of the first (14–16 years old) and third groups (17–18 years old) took part in only one tournament. Athletes of the second (14–16 years old) and fourth (17–18 years old) took part in matches in both competitions. Using indicators of heart rate variability and biochemical analysis of cortisol concentration in the blood, the nature of adaptive changes of the participants' bodies to a given physical stimulus was determined. 2 tests were used: execution by athletes of a series of lateral kicks on the makiwara for 15 and 40 s with maximum force. The Results. It was established that at the beginning of the study, the athletes of groups 2 and 4, who were trained in duels only during one competition, had a less strained regulation of the heart rhythm (LF/HF<1,15) compared to representatives of the other two groups. In athletes of groups 1 and 3, in response to exercise, we observed a decrease in SDNN values by an average of 26,2 % and LF by 24,3 % against the background of an increase in HF parameters by 2,8 %. Representatives of the other two groups, on the contrary, showed an increase in SDNN (+25,9 % and +34,8 %) and LF value by an average of 26,9 % against a background of a decrease in HF parameters by 22,0 % in response to exercise during 40 p. It was found that in athletes of groups 1 and 3, the concentration of cortisol in blood serum is 40,3 % higher than the parameters fixed in representatives of groups 2 and 4, but do not go beyond the physiological norm. Among the subjects of group 1, the level of the studied hormone in response to special loads for 40 seconds shows a significant decrease by 40,5 %, and among the participants of group 3 by 50,1 % compared to the state of rest. Among other participants, we observe an adequate reaction to a stressful stimulus, which is manifested in the growth of this steroid hormone in blood serum (+32,5 % in athletes of the 2nd group; +11,8 % in the 4th group). Conclusions. The results revealed in the research show that qualified MMA athletes of adolescent and youth age, after participating for a short period of time simultaneously in two international tournaments, during the recovery period need to reduce loads to 40–45 % of 1 PM and use only aerobic mode of energy supply. It was established that during the recovery period, the use of specialized for this type of sport load leads to the manifestation of compensatory mechanisms associated with the activation of gluconeogenesis processes and the strengthening of the vagal influence on the sinus node of the heart of athletes.

Multiphase soft metal enabled high-performance fabric-based wearable energy harvesting

Highly efficient and flexible power sources have always been the focus and goal in the field of wearable electronics. However, the existing wearable power sources are limited by their large size, high weight, electrolyte leakage, and poor mechanical compliance, which seriously hinders their practical applications. Herein, we propose a novel strategy to achieve and demonstrate a fabric-based high-performance wearable triboelectric nanogenerator (TENG) structure. The metals of gallium (Ga), bismuth (Bi), indium (In), and tin (Sn) are mixed according to specific mass ratios, and then they are transformed in liquid phase to form room-temperature multiphase soft metals of GaBiInSn. The material exhibits both metallic and fluidic properties, and possesses a characteristic of multiphase structure. The GaBiInSn material is directly deposited between polytetrafluoroethylene (PTFE) layers and nonwoven fabrics to establish multi-level conductive and frictional interfaces, creating charge transfer and solid-liquid hybrid dielectric layers. Therefore, the thin film-type triboelectric nanogenerators with a structure of PTFE/GaBiInSn/nonwoven fabric (LM-P-TENGs) is manufactured. The LM-P-TENGs can be integrated onto fabrics without compromising their breathability, comfortableness, and flexibility. Particularly, LM-P-TENGs efficiently convert the mechanical energy of human limb movements into sustainable electrical energy output. Under the human limb mechanical triggering conditions, LM-P-TENG achieves a champion specific open-circuit voltage up to 900 V, peak short-circuit current density of 43.3 mA/m2, and high power density of 12.56 W/m2. This work demonstrates the application potential of room-temperature multiphase soft materials in flexible wearable power sources, while introducing a novel power supply mode for wearable electronics. Additionally, the LM-P-TENGs also present applications in self-powered wearables, medical biosensing systems, human-machine interaction systems, near-eye display systems, etc. for the flexible electronics.