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The sterile paper-plastic barrier system for packaging sterilized medical equipment is studied, the main factors affecting its breakdown are revealed, and the inhalation rate during the pressure sterilization is experimentally analyzed. The results offer a new window of opportunity for a stricter risk-analysis and a robust strategy for the pressure sterilization, and this paper can be served as an example of strict clinical applications. [ABSTRACT FROM AUTHOR]

The limitations of the polysulfides shuttling and lithium dendrites have been obstacles to improve the lithium-sulfur battery technology, resulting in low active material utilization and poor cycle life. Here we report a simple modification of the traditional lithium-sulfur battery configuration to achieve high capacity with a long cycle life and high reversible rate. Great improvement was observed with a carbonized PAN/PMMA/rGO paper between the anode and the separator in the active material utilization and capacity retention. The adding of a free-standing PAN/PMMA/rGO carbon interlayer demonstrated the feasibility of enhancing the performance of lithium-sulfur batteries. [ABSTRACT FROM AUTHOR]

In this study, a microstrip patch antenna design with a U-shaped patch and a paper-based substrate is presented. Metallic parts such as the patch, ground plane and microstrip line feed are designed in aluminum. Utilization of recyclable paper and aluminum yields a sustainable and environmentally friendly design. The dual-band antenna operates between 1.950-2.125 GHz and 2.650-2.825 GHz with a bandwidth of 0.175 GHz for both frequency ranges. It is suitable for multipoint distribution systems (2.076-2.111 GHz) and WiMAX application (2.700--2.800 GHz). Monopolar radiation patterns are obtained for the operation frequencies of both frequency ranges. Maximum gain values are 5.009 dBi and 5.413 dBi for the operation frequencies of multipoint distribution systems and WiMAX application, respectively. While the antenna can be used indoors and outdoors, radome design is not considered in the structure. No parasitic elements or slots are included in the antenna. All simulations are carried out by using ANSYS HFSS software package. [ABSTRACT FROM AUTHOR]

Producing pyrolytic oil via pyrolysis reaction from waste papers containing melamine formaldehyde and urea formaldehyde, which have an economic and environmental value, is the base of this study. In this study gas, liquid and solid products were gained via pyrolysis, and liquid products are put into perspective from the point of energy. In this pilot study, positive results were obtained for comprehensive further experiments, and it's seen that the results may have meaningful value on sectoral basis with regards to reducing environmental damages of the wastes and energy producing. [ABSTRACT FROM AUTHOR]

Meta-aramid fibrid is prepared by precipitation, and aramid fibers are mixed with meta-aramid fibrid to make aramid paper by hot-pressing technology. Meta- -aramid fibrid possesses an excellent binding and adhesive properties with the aramid short fibers, yielding high mechanical properties of the aramid paper. The effects of hot-pressing temperature on the mechanical property of metaaramid paper are mainly discussed. Experimental results indicate that the mechanical property of aramid paper increases first and then decreases with the increase of hot-pressing temperature. The fundamental cause of this phenomenon is elucidated, and the aramid paper reaches its maximal mechanical property when the hot pressing temperature is 300 °C.. [ABSTRACT FROM AUTHOR]

The moisture content of oil-filled transformers insulation paper that is a cellulose- containing material comprises 8% to 10% of moisture by weight at ambient temperature and it is highly important to decrease the moisture content for effective use of a transformer. Vapor phase drying is more effective method for drying the insulation paper of the transformer as compared with other conventional methods due to less cycle time and energy consumption. The purpose of this paper is to design a solvent operated drying chamber in which drying of the insulation paper of oil filled transformer carried out. The approach of the present paper is to develop a numerical model to reduce the cycle time of the drying process. The unsteady flow, heat, and mass transfer phenomena were simulated by using CFD solver. Theoretical studies and a numerical model were conducted over thermal calculation in the drying process using solvent at different pressures. Theoretical calculations were used to validate the numerical model. Drying chamber was optimized by using response surface methodology. The result of the study showed that drying cycle time was decreased almost 14.3% with the new design. Furthermore, when the solvent was used instead of air as a heat carrier, the drying cycle time was reduced. [ABSTRACT FROM AUTHOR]

Non-linear programming optimization method was used to optimize total steam and air consumption in the dryer section of multi-cylinder fluting paper machine. Equality constraints of the optimization model were obtained from specified process blocks considering mass and energy balance relationships in drying and heat recovery sections. Inequality constraints correspond to process parameters such as production capacity, operating conditions, and other limitations. Using the simulation, the process parameters can be optimized to improve the energy efficiency and heat recovery performance. For a corrugating machine, optimized parameters show the total steam use can be reduced by about 11% due to improvement of the heat recovery performance and optimization of the operating conditions such as inlet web dryness, evaporation rate, and exhaust air humidity, accordingly total steam consumption can be decreased from about 1.71 to 1.53 tonnes steam per tonne paper production. The humidity of the exhaust air should be kept as high as possible to optimize the energy performance and avoid condensation in the pocket dryers and hood exhaust air. So the simulation shows the supply air should be increased by about 10% to achieve optimal humidity level which was determined about 0.152 kgH2O/(kg dry air). [ABSTRACT FROM AUTHOR]

The calculating of reached ageing based on the history of loading according of International Electrotechnical Commission standard algorithm is the first task. In order to verify the obtained results, measurements of polymerization index were made on 28 paper samples taken directly from low voltage terminals (winding ends) and bus connections of the transformer under test rated 380 MVA, 2x15,75 kV/420 kV. The complete procedure of paper sample locations and taking off is described, thereby providing a manner of how this should be done, determined by specific conditions of the transformer under test. Furthermore, the determination of limit viscosity and using its relationship function with polymerization index are explained together. Comparison is made with those of liquid chromatography of oil. The results of particle sort and size analysis are shown. Finally, an estimation of the transformer life remainder is made, which is of paramount importance when defining the steps that have to be made either in revitalization process or in transformer replacement planning. [ABSTRACT FROM AUTHOR]

This investigation proposes a systematic framework based on the Fault Tree analysis, for the energy and exergy optimization of a paper machine. In the first step, energy and exergy analysis was performed on the dryer section and its related steam and condensate system, to assess the existing performance of paper machine. In the next step, checklists were developed for the identification of key safety and operational issues related to the steam and condensate system. Then, a fault tree analysis was applied to make out and resolve the root causes. Corrective actions were taken in order to rectify various problems. As a result, energy and exergy efficiencies of the system increased by 22% and 14%, respectively. Moreover, an improvement in steam and condensate recovery system was observed. [ABSTRACT FROM AUTHOR]

The current discussion is presented to increase the awareness among the readers of the journal Thermal Science. Comments are presented in particular on the paper by Hayat et al. [1] where the authors investigated effect of non-linear radiative flow of third grade fluid and temperature dependent heat source with chemical aspects. The current discussion concerns some questionable results included in the aforementioned paper. [ABSTRACT FROM AUTHOR]

When a tunnel fire occurs, due to the difference of tunnel width and slope, both smoke countercurrent length distribution law and critical velocity will become different, and these two are very important parameters in tunnel longitudinal ventilation design. Therefore, for the design of smoke control and longitudinal ventilation of the tunnel, based on actual highway tunnel size, this paper established and ran a series of numerical simulations through FDS simulation software to study tunnel width and slope's effect on smoke countercurrent length and critical velocity. The results of this paper show that smoke countercurrent length decreases with tunnel slope's increase and increases with tunnel width's increase. Through dimensionless analysis, the prediction formulas of smoke countercurrent length and critical wind speed of large cross-section tunnel about tunnel width, slope and height are modified and established. The research conclusions can provide a theoretical basis for the longitudinal ventilation design, smoke prevention and exhaust measures and personnel evacuation in large cross-section tunnel fires. [ABSTRACT FROM AUTHOR]

In this paper, the thermodynamic and economic efficiency of three different heat supply processes are compared, based on exergy flows and costs of heat. A gas turbine process with a heat recovery boiler, a gas and steam turbine combined cycle process and a high temperature heat pump system recovering waste heat are analysed. The aim is to provide heat as 4 bar(abs) saturated steam. The economic analysis bases on the comparison of the consumption-related costs of heat, the capital-related costs of heat, and the operation-related costs of heat. The results show that the heat pump system has higher exergetic efficiency than the gas turbine or the gas turbine combined cycle process. For the consumption related costs, the economic calculation shows that the operation of a heat pump, working with a coefficient of performance of four and for a natural gas price of 25 €/MWh, is the cheapest way of heat production as long as the electricity price is lower than 45 €/MWh. For the period from January 2013 until June 2016 the total costs of heat, based on real gas and electricity prices from the European Energy Exchange, are calculated and analysed. The results show that the share of heat provided by the heat pump system varies between 45% and 76%. Especially in 2013 and 2014, the economic conditions for operating heat pumps were very good. Since October 2015 the natural gas prices have seen a decrease which favours industrial heat supply with combined heat and power systems. [ABSTRACT FROM AUTHOR]

This paper considers a temperature-dependent thermal conductivity with memory property in a fractal space. The two-scale fractal derivative is adopted to model the temperature field in the spatial dimensions, and Caputo fractional derivative is used to describe its memory property. The variational iteration method is employed to solve the mixed model with great success. This paper offers a new window for studying intractable problems arising in porous media or unsmooth boundaries. [ABSTRACT FROM AUTHOR]

The paper aims at predicting the remaining useful life of highly reliable and long-life products with multiple and multi-stage characteristics in the degradation process. Considering the unit-to-unit variability among the product units, a new bivariate and two-phase Wiener process model with random effects is established. Schwarz Information Criterion is used to identify the change points of the degradation model, and the analytical expressions of life and remaining useful life are given by the concept of first hitting time. Furthermore, the appropriate Copula function is selected to describe the correlation between the two quality characteristics based on Akaike Information Criterion. A bivariate degradation model is established and the unknown parameters of the model are estimated by Markov Chain Monte Carlo method. Finally, the applicability and effectiveness of the proposed method are verified by the comparative analysis of turbine engine. [ABSTRACT FROM AUTHOR]

The challenge for a non-linear vibration system in a fractal space is more fractal dimensions than frequency-amplitude relationship, the system energy consumption depends upon its fractal property, so its best-case scenario is to establish a relationship among the fractal dimensions, frequency and amplitude. For this purpose, this paper studies a fractal-fractional vibration system of a mass attached to a stretched elastic wire in a fractal space, and its asymptotic periodic property is elucidated, the effect of the fractal dimensions on the vibration system is discussed. This paper offers a new road to fast and reliable analysis of fractal oscillators with high accuracy. [ABSTRACT FROM AUTHOR]

This paper studies a local fractional vibration system with a damped non-linear term to reveal its frequency property and its energy consumption. A modification of He's frequency formulation is recommended for this purpose. Some examples are given to illustrate the solving process and the reliability of the method. Additionally, the effect of the initial conditions on the vibrating properties is elucidated. This paper offers a new window for fast and effective insight into local fractional vibration systems. [ABSTRACT FROM AUTHOR]

In this paper, the permeability of sandstone, mudstone, gangue, and limestone under the condition of initial elastic deformation is obtained by transient method test. Mercury intrusion test is carried out on the four kinds of rock samples to obtain the initial permeability of the rock samples. The results show that the magnitude of permeability obtained by mercury intrusion test and transient method test is completely consistent. The measurement error is analyzed. The relative error of permeability in this paper is less than 6.0%. It can be showed that the use of transient method to measure the permeability of rock samples is reasonable and reliable. [ABSTRACT FROM AUTHOR]

Under the goal of "achieving carbon peak by 2030 and carbon neutrality by 2060", how to select the type of fresh air system has become a key area of energy conservation. The method of outdoor design PM2.5 concentration is one of the important factors affecting the selection of fresh air filtration system. This paper first analyzed the PM2.5 concentration values of 31 cities in China from 2017 to 2020 based on mathematical induction, and next gave the recommended coefficient K under six urban economic regions methods in combination with the actual situation. Finally, the selection of air filters in five typical cities was taken as an example, the differences in recommended coefficient K and selection of outdoor design PM2.5 concentration under different recommended methods were compared and analyzed. The results showed that the recommended coefficient K under the six economic regions could meet the required K value needs of the region. The recommended coefficient K by the six economic regions methods based on per capita GDP is the best. Under that conditions, the recommended coefficient K of the five typical cities under strict and normal conditions differs from the average K values of the six methods by 0.06 and 0.04. This paper will provide a new method for the correct selection of outdoor design PM2.5 concentration in fresh air systems to achieve the dual carbon energy-saving goal. [ABSTRACT FROM AUTHOR]

The current flat-plate solar collectors perform best when their absorbers rotate around their axis. However, with their concentrators, reflectors, and tracking mechanisms, they take up a lot of space and are thus commercially speaking, not the best solutions. This paper proposes a novel solar collector design which employs the (relative) rotation of absorbers, but strives to combine the benefits of fixed and (absolute) tracking solar systems, i.e. volume occupancy from the former and thermal performance from the latter. The findings of our numerical analysis show that, the solar irradiance efficiency of this novel design is 20% higher than that of a fixed flat-plate collector during clear-sky days, and it is equally lower than that of an absolute tracking collector. This paper also introduces a new criterion for describing single-axis tracking solar collectors which should be included in the classifications of solar collectors. Finally, the article, which represents a continuation of our research in the field of solar energy utilization, can contribute to the future development of solar technologies and solve some of the current challenges. [ABSTRACT FROM AUTHOR]

The combined production of electricity and thermal energy (combined heat and power or co-generation) is the most efficient and convenient approach to reduce costs for energy at industrial power plants and district heating plants that use natural gas as fuel to produce thermal energy for various needs. This paper analyses the operational characteristics of the combined heat and power plant, which has been operating since January 1, 2021, at the Voždovac Heating Plant as part of the Belgrade district heating system. The combined heat and power plant consists of three gas engine units with a total nominal electric power of 10 MW and thermal power of 10.1 MW, which use natural gas as fuel. The combined heat and power plant is used for district heating and preparing domestic hot water while electricity is sold to the local electric grid. The analysis in this paper focuses on the plant's operational characteristics: the number of working hours, the total energy consumption and energy production, the efficiency as well as the operational and maintenance costs. Also, the impact of the drastic changes in the prices of natural gas, electricity, and maintenance costs in the last year on the financial profitability of the combined heat and power plant was analysed in particular. [ABSTRACT FROM AUTHOR]

In this paper are presented desing, testing and numerical analysis for two manufactured control valve trims. Valve trim is consisted of cage or dick stack, plug, stem and seat. Size from app. 15.88 mm (0.625 in) up to 101.6 mm (4 in) is suitable for 3-D metal and plastic print, what is presented in this paper. Selective laser melting 3-D metal printing is applied on the disc presented in this paper. Even better material properties from rest of the valve parts could be obtained. This is of great importance for valve retrofitting. In this paper is presented, also, new developed channel geometry, what is followed by various fluid-flow phenomena. Measurement results for second prototype manufactured by 3-D printing using plastics are presented in details. Here is shown, in short, procedure for determination of KV values of the test valves according to the EN 60534-2-3, Industrial-process control valves - Part 2-3: Flow capacity - Test procedures. In addition, some aspects of CFD calculations are presented. [ABSTRACT FROM AUTHOR]

Traditional research of environmental impact of natural draft cooling tower in nuclear power plant is based on diffusion model or tunnel experiment, and with the development of modern mainframe computers and turbulence models, it is possible to use CFD method to simulate plume drift. The CFD software, due to its powerful computing ability, can simulate and display the plume drift more accurately. This paper presents an effective way of generating terrain grids which can be used in StarCD, a CFD software. The SRTM terrain data is obtained from internet and IDW interpolation method is used in the co-ordinates translation process. A powerful program named GridInter is developed using Fortran90 to convert terrain data to StarCD vertex file, terrain grids generation process in StarCD including nuclear power plant building grids combination is also introduced, this model can be directly used in the numerical simulation of plume dispersion. [ABSTRACT FROM AUTHOR]

In this paper, a generalized equal width wave equation involving space fractal derivatives and time Caputo fractional derivatives is studied and its approximate analytical solution is presented by the Adomian decomposition method. An example shows that the method is efficient to solve fractal non-linear partial differential equations. [ABSTRACT FROM AUTHOR]

A beam vibration originating in the beam porous structure or on a non-smooth boundary might make its vibrating energy concentrated on a single wave, leading to a solitary wave. This paper applies the variational approach to analysis of the soliton basic property, and the effect of the fractal dimensions on the solitary wave is elucidated. This paper is to draw attention the beam soliton property beyond its widely known resonance and periodic and chaotic properties. [ABSTRACT FROM AUTHOR]

The available potential energy of the diurnal internal tide in the Northwest Pacific ocean is studied by using short-term high-frequency mooring observations. The results show that in the upper layer of the ocean, its distribution is relatively chaotic, and it is greater between 1500-1600 m and 2500-3000 m in the middle layer of the ocean. At other depths, it is generally smaller, especially, at the bottom layer of the ocean, it is relatively small. This paper concludes that the marvel of measurement is the best science picks. [ABSTRACT FROM AUTHOR]

The stochastic P-bifurcation behavior of bi-stability in a generalized van der Pol oscillator with the fractional damping under colored noise and thermal excitation is investigated. Firstly, using the principle of minimal mean square error and linearization method, the non-linear stiffness terms can be equivalent to a linear stiffness which is a function of the system amplitude, and the original system is simplified to an equivalent integer order van der Pol system. Secondly, the system amplitude stationary probability density function is obtained by the stochastic averaging, and then based on the singularity theory, the critical parametric conditions for the system amplitude stochastic P-bifurcation are found. Finally, the types of the stationary probability density function of the system amplitude are qualitatively analyzed in each area divided by the transition set curves. The consistency between the analytical results and the numerical results acquired from Monte-Carlo simulation also testifies the theoretical analysis in this paper and the method used in this paper can directly guide the design of the fractional order controller to adjust the response of the system. [ABSTRACT FROM AUTHOR]

The micro-electro-mechanical system is widely used for energy harvesting and thermal wind sensor, its efficiency and reliability depend upon the pull-in instability. This paper studies a micro-electro-mechanical system using He-Liu [34] formulation for finding its frequency-amplitude relationship. The system periodic motion, pull-in instability and pseudo-periodic motion are discussed. This paper offers a new window for security monitoring of the system reliable operation. [ABSTRACT FROM AUTHOR]

The meteorological parameters, e.g., wind direction, wind speed and atmospheric stability, affect greatly the diffusion of pollution and radiological environmental impact assessment. Based on the hourly meteorological data obtained from an automatic monitoring station, the radiological impact indicated by the air concentration, individual dose and maximal individual effective dose were analyzed and compared between 2020 and 2021. The paper concluded that children are the main group to be the most easily infected, and the critical exposure path is internal exposure from inhalation. This paper offers a new window for timely decision-making for radiological safety under different climate conditions. [ABSTRACT FROM AUTHOR]

A prediction of rod wave type with great precision is extremely important in theoretical analysis and practical applications. Besides the well-known periodic motion and resonance, this paper studies the rod wave in a fractal space, and a fractal solitary wave is unlocked by the variational approach, the results reveal that the rod strain non-linearity and fractal dimensions affect greatly the wave travelling properties. This paper offers a new window for identifying a solitary wave from periodic motion easily and accurately. [ABSTRACT FROM AUTHOR]

Wind turbine blades are the main component of wind turbines to capture effective wind energy, and require good quality and reliable performance. Therefore, the manufacturing cost of wind turbine blades is much higher than that of other components of wind turbines. The blade is a slender elastomer prone to vibration. The wind turbine vibration always arises in the blade instability. At the same time, the blade is also a typical aerodynamic component. In the process of rotation, it will not only produce mechanical vibration but also bear aerodynamic force. In this paper, the mechanical properties and modal numerical simulation analysis of composite blades with different hybrid ratios of carbon fiber and glass fiber are analyzed, it is found that with the increase of carbon fiber content, the mechanical properties of the blade gradually increase, and the torsional vibration resistance of the blade become stronger. Therefore, the wind turbine blades of hybrid fiber composites have a longer service life, which can reduce material wastage and help protect the environment. [ABSTRACT FROM AUTHOR]

This paper uses the biomass of livestock, poultry manure and straw to study the resource utilization and integration technology by division and classification. The SPSS regression analysis and integration were applied to analyze the economic benefits of the base period (2018) and the audit period (2020). The analysis gives an opportunity in rural areas to reduce chemical fertilizers, pesticides, electricity and coal cost in planting, and this paper opens a novel window for utilizing renewable energy resources and reducing carbon dioxide emissions. [ABSTRACT FROM AUTHOR]

In this paper, a combined air/water source heat pump water heater is presented. At ordinary time, the heater can be used for hot water heating in water-source mode to improve the energy efficiency. While in cold season, it gives priority to air-source mode for water heating to improve operational safety. Experiments were conducted to investigate the thermodynamic performance of the heater in each operation mode, and the experiment results were analyzed. The research indicated that its operation was reliable during the long-time running. This paper offers a promising energy-saving method in future. [ABSTRACT FROM AUTHOR]

In order to understand the solar heat pump heating system, a phase-change storage solar heat pump heating system based on cloud computing is proposed. This paper first introduces the solar heat pump as a phase change energy storage that can change four types of heat depending on the weather conditions and significantly reduce the energy consumption of the system. Second, through the special design of the energy storage capacitor, in addition adjusting the energy distribution of the solar heat pump system, it can also improve the reliability of supply and demand between the solar heat pump system and the building heating system, improve the level of solar energy consumption, but also improve the low temperature of the pump milk temperature, and improve the solar heat up quickly to achieve the goal of improving the overall performance of the heat pump. Finally, this paper takes an urban "electric coal" house as a research object to investigate the hot air efficiency of solar heat pumps. This paper analyzes the daytime solar heat pump mode, the nighttime energy storage mode under extreme conditions, and the air source heat pump mode. And shows the research results that the solar heat pump has good heating efficiency and the highest solar COP. Will be heat pump is 5.28 solar energy average heat pump COP is 2.13. In very bad weather, solar heat pumps work better. [ABSTRACT FROM AUTHOR]

In order to understand the application and thermal process of solar energy storage system in building structure design, a research on the application and thermal process analysis of solar energy storage system in building structure design is put forward. This paper will take the outdoor climate conditions of residential buildings in a province as an example to conduct thermal analysis on the heat collection components and heat storage components of urban residential buildings. The building under test is a university teacher's residence located in the university campus of Chengguan District of the city. It is a multi-storey building with a total of five floors, and the building is on the top floor. The experimental results show that the heat storage effect of the thick exterior wall can effectively reduce the temperature fluctuation of the exterior wall. The difference between the maximum and minimum values of the exterior wall surface temperature is 19 °C, and the difference between the maximum and minimum values of the interior surface temperature is 5.4 °C. The difference between the maximum and minimum temperature of the north exterior wall is 4.9 °C, and the difference between the maximum and minimum temperature of the inner surface is 1.6 °C. The work of this paper lays a foundation for the quantitative research on the temperature control of building heat collection and storage components, and provides a theoretical basis for solar heat storage. [ABSTRACT FROM AUTHOR]

In order to understand the application of frost measurement of air source heat pump heat exchanger, a research on frost measurement of air source heat pump heat exchanger based on image recognition processing technology is put forward. In this paper, the scheme design of defrosting control system based on image processing technology is introduced, and the frost degree coefficient of outdoor heat exchanger fin surface is introduced to characterize the frost degree of fin surface. Secondly, the experimental environment room was built, and the conventional defrosting control method of the existing heat pump unit was tested on the spot. It was found that in the air temperature of -6~0 °C and the air relative humidity of 86~92%, the unit appeared the phenomenon of "defrosting in time" and "defrosting without frost". Finally, the change of frost layer on the surface of the outdoor heat exchanger fin during defrosting is analyzed, and the coefficient of frost degree on the surface of the fin is calculated and analyzed. At the beginning of defrosting, due to the large degree of frost, the P-value of the frost degree coefficient on the surface of the fin is close to 1, when the defrosting is carried out for 125 seconds, the P-value of the frost degree coefficient on the surface of the fin decreases sharply to 0.09, when the defrosting is completed, the P-value of the frost degree coefficient on the surface of the outdoor heat exchanger is maintained at about 0.04. The defrosting control method of air source heat pump based on image processing technology is proposed in this paper, and its technical feasibility and effect are verified by experimental tests, which lays a foundation for future popularization and application. [ABSTRACT FROM AUTHOR]

In order to understand the application of iot Big data information acquisition for heating control systems, a research on iot Big data information acquisition for thermal storage heating control systems is proposed. This paper first analyzes the shortcomings of the traditional heating system, the heating data is scattered and difficult to collect. The IoT technology is applied to the heating platform through data acquisition, data visualization, data mining, data management and other aspects. Secondly, the application of the IoT in heating system data acquisition is studied, including the types of heating data collected, data acquisition process, data acquisition standards, etc. Finally, this paper takes the energy-saving transformation of 26 boilers in a heating enterprise as an example. The research results show that the boiler efficiency obtained in real time by using the online monitoring system of this project is 95.36%, and the reverse balance boiler efficiency in the paper report of the special inspection office is 94.88%, with a deviation of 1.48%. The application of the IoT technology can obtain the boiler indicators in real time and effectively, and can realize the comprehensive analysis of the monitoring data, and realize the evaluation of the energy efficiency operation state of the gas boiler and the fault diagnosis and early warning. The IoT technology is an effective means of fine energy-saving management in heating enterprises. [ABSTRACT FROM AUTHOR]

Along with the rapid economic development and social progress, the problem of energy and environment is becoming more and more outstanding. Therefore, it is very important to use new energy saving techniques to increase energy consumption and reduce energy consumption. In this paper, we have developed a hot water system, which is based on solar energy technology, gas-source heat pump, and phase change energy storage technology. The system was designed and constructed, and its performance was tested in various control conditions, with an emphasis on the analysis of the influence of phase change heat supply on heat storage properties. In this paper, the effect of the heat storage property is analyzed. Studies have shown that compared to a conventional tank that does not have a phase change heat storage device, the heat storage tanks equipped with phase change energy storage devices have longer discharge time, higher discharge temperature, better temperature, and better operation efficiency. In addition, the data show that flow rate control is also an important factor in optimizing the thermal storage characteristics of the system. [ABSTRACT FROM AUTHOR]

In the process of preparation and service, the carbon fiber reinforced polymer (CFRP) material is prone to defects such as delamination and inclusions, which seriously impact the normal use. In this paper, non-linear frequency-modulated (the logarithmic sweep) thermal excitation is used to carry out finite element simulation and experimental research. In order to investigate how different detection process parameters affect defects, the impact of different detection parameters on the surface temperature difference and contrast is analyzed, and the detection parameters that can quickly identify defects and have better recognition effect are obtained. [ABSTRACT FROM AUTHOR]

In this paper, a permeability parameter calculation model with six influence coefficients is constructed by taking volume strain and equivalent strain under Coulomb-Mohr criterion as independent variables. The optimal estimates of permeability parameter influence coefficients are applied to the prediction of permeability parameters under a complex loading path, and the prediction results verify the applicability of the model. [ABSTRACT FROM AUTHOR]

In this paper, on the basis of laboratory triaxial mechanical experiments, a granite model including different numbers and angles of fractures was established by the discrete element method. Combined with the laboratory triaxial mechanical experiments and PCF simulation results, the effects of the number and angle of fractures on the rock mechanical properties of fractured granite reservoirs were analyzed. The results show that the existence of fractures significantly reduces the strength of the reservoir, but the increase of the fracture angle and the confining pressure will weaken the degree of this reduction, and the fractures are easy to expand and connect during the loading process. [ABSTRACT FROM AUTHOR]

Manufacturing knowledge can be preserved through knowledge accumulation and continuous integration. In order to improve the using efficiency of manufacturing knowledge, this knowledge is stored and used in the way of Knowledge graph. This paper will study the construction of Knowledge graph based on manufacturing process methods and the ability of Knowledge graph to provide services. This kind of manufacturing knowledge capability not only provides the manufacturing realization method of processing technology, but also can correspond to the design realization method of design graphics, providing theoretical support for the integrated realization of design and manufacturing process. [ABSTRACT FROM AUTHOR]

Lung is the most important gas exchange organ of human, and the smooth airway is the basis of lung function. The condition of the trachea is associated with a variety of diseases. In this paper several methods of tracheal simulation based on CT-based data since 2003 are reviewed. Reasonable algorithms and image processing methods are important development directions for airway scanning reconstruction. The development of airway reconstruction needs to be closely integrated with mathematical modelling to improve the accuracy and precision of reconstruction. [ABSTRACT FROM AUTHOR]

This paper introduces a novel design for a solar photovoltaic/thermal (PV/T) air collector that utilizes staggered fins. The collector features double-layer flow channels in the same direction, with the upper channel equipped with transparent wave plates, and the lower channel fitted with staggered fins. The paper includes a calculation scheme for wave plate heat balance. The numerical model of the collector is established and verified by experimental results. A numerical model is used to analyze the height combination of the upper and lower runner and the fin arrangement of the lower runner. The results indicate that, under the given environmental parameters, as the PV panel moves down, the overall air heat transfer capacity decreases. When the height combination of the upper/lower runner is 23 mm/105 mm, the maximum value is 53.741%. With the increase of fin spacing, the heat transfer capacity of the lower runner decreases. With the increase of the number of fin rows, the heat transfer capacity of the lower runner increases. When the equivalent diameter of the rectangular channel and the number of fin rows were 70 mm and 3 rows, respectively, the maximum solar energy comprehensive utilization efficiency was 56.261%. [ABSTRACT FROM AUTHOR]

In order to solve the problem of optimal allocation of general heat resources in high permeability renewable energy distribution network, an optimal allocation scheme of general heat resources in renewable energy distribution network is proposed. The optimal allocation scheme in renewable energy distribution network is proposed. In this paper, the internal and external two-layer structure is designed. The outer layer uses genetic algorithm to search the structural parameters of general energy system, and the inner layer uses dynamic programming method to get the optimal performance of general energy system. The internal and external alternate adjustment methods are used to optimize the general-purpose power distribution capability of the continuous-wave power supply network with different permeability and controllability, and the proposed method is verified in IEEE 33 node distribution network. The experimental results show that the general strength storage capacity is 26.6% and 45.7% higher than that of the process with a continuous strength renewable permeability of 30% and 40%, respectively. The utility rates were increased by 18.4% and 27.8%, respectively. Under the condition of high permeability renewable energy, the proposed method can increase the efficiency of resource management of distribution network by regulating load, decrease the distribution capacity of energy stability, and reduce the operation cost of the system. [ABSTRACT FROM AUTHOR]

This editorial provides an overview of ten scientific articles published as the Special paper selection in Thermal Science. The papers were selected from almost six hundred contributions, presented at the 16th Conference on Sustainable Development of Energy, Water and Environment Systems (SDEWES 2021), held on October 10-15, 2021 in Dubrovnik, Croatia. The topics covered in the Special paper selection include economics of electricity markets, nuclear technology, repowering of the coal-based power plant, hybrid renewable energy system, sustainable biomass handling and conversion, post-combustion emissions control, and efficient cooling technology. The editorial also emphasised the papers recently published in the Special Issues of leading scientific journals dedicated to the series of SDEWES Conferences. [ABSTRACT FROM AUTHOR]

Air knives with very different nominal values are used for various purposes in the industry. The uses of air knives include the painting and coating stages of automobile semi-finished products, as well as many stages related to food production. One of the important sectors among these is the continuous hot-dip galvanizing process, which is a coating technique in the steel industry. In addition, the chemical coating process on paper as a very thin layer is another research topic. The most critical process needed in these sectors is to ensure a homogeneous air-flow at the expected air speed of the air-knife. These determine whether the coating on the steel or the chemical layer on the paper is homogeneous at the desired thickness. In this study, it is aimed that the air-knife can reach the expected values (speed and homogeneous distribution) with the expected tolerances, the shortest time, cost, and the least production process error. First, a design has been made so that this knife can blow air at the desired speed and homogeneously. For this, the most appropriate modeling and design values were created and analyzed with the CFD. The analysis and evaluations of the design were confirmed as a result of the measurements made on the prototype. This study shows that the inclusion of this type of modeling and analysis in the rapid product development process has an important role in minimizing cost and time. [ABSTRACT FROM AUTHOR]

Today, the World Health Organization has declared a global health emergency, caused by the Monkeypox outbreak. In the monthly analysis for June, 3500 cases have been reported in 50 countries around the world. In the analysis for July, more than 30000 cases have been reported in 75 countries. Thus, in the circumstances of the continuing COVID-19 pandemic, the appearance and dynamics of spreading of Monkeypox is alarming. In this paper, for the first time, elemental composition of Poxvirus, Monkeypox virus, and Vaccinia virus have been reported. Additionally, thermodynamic properties have been reported for nucleic acids, nucleocapsids, and entire virus particles. The similarity in chemical composition and thermodynamic properties of the analyzed viruses has been used to explain the crossed immunity to Poxviruses. Finally, binding thermodynamic properties have been reported for the Vaccinia virus. [ABSTRACT FROM AUTHOR]

Several recently signed environmental agreements and protocols emphasize the global need to reduce GHG emissions, with a focus on limiting coal consumption due to high NOx and CO2 emissions. However, many countries, including those in the Western Balkans, rely heavily on coal for electricity generation. The outdated thermal power plant infrastructure in these regions poses a major challenge when it comes to meeting modern environmental standards while maintaining efficiency. This study is part of the more comprehensive research which aims to develop an expert system that utilizes existing measurements to estimate key parameters crucial for both energy production and pollution reduction. The focus is on Serbian thermal power plants, particularly plant Nikola Tesla unit B1. One of the critical parameters for optimizing thermal power plant control loops is the heating value of coal, which is challenging to measure in real time due to the coal's varying chemical compositions and caloric values. This paper examines 74 different parameters measured in 59 instances to estimate the hating value of coal at unit B1. Through detailed analysis and feature selection methods, including linear regression, this research aims to identify the most informative parameters for estimating the heating value of coal, which will improve the control system that enables more efficient and environmentally friendly power generation in coal fired thermal power plants. [ABSTRACT FROM AUTHOR]

In this paper, the effects of different burner configurations on the characteristics of flameless combustion were evaluated by comparing the temperature field, NOx, OH, and H2CO at different burner inlet velocity and angles through a combination of experimental and numerical simulations. The results show that increasing the burner inlet angle and gas velocity is imperative in achieving the flameless combustion, increasing the re-circulation rate in the furnace, making the temperature distribution in the furnace uniform, and reducing the emission of NOx at the end of the furnace. During the simulation of flameless combustion, it was found that OH radicals and H2CO radicals were well correlated with the reaction exothermic zone, and the Reynolds number was positively correlated with the re-circulation rate in the furnace. With the increase of Reynolds number, the entrainment rate of flue gas increases, and the combustion state is closer to flameless combustion. When re-circulation rate Kv >2, combustion becomes flameless. Through the summary analysis of the data, it can be found that there is a critical Reynolds number for the burner to achieve flameless combustion, and flameless combustion occurs only when the Reynolds number is greater than 1.0·104. [ABSTRACT FROM AUTHOR]

This paper was written to demonstrate the value of using nanofluids for cooling high power transformers while also providing current techniques for business and academia. A numerical analysis of the improvement caused by the cooling of a high voltage transformer using nanofluids has been done. A tank with a temperature source inside and a charge of mineral oil-barium titanate nanoparticles is used to study natural-convection. This study investigates the effects of variables on the thermal efficiency of the tank, including the thermal Rayleigh number and volume fraction. The results show that quenching varies with low and high Rayleigh thermal numbers and depends on the volume percentage of used nanoparticles. The effects were illustrated in thermal transfer rate representations as functions of the thermal Rayleigh number (Rat = 103 and 106) and the solid volume particle from the nanoparticles (0% = f < 10%). The findings showed that improving the solid volume particle of the nanoparticles by 10% causes the fluid being utilized to become more effectively conductive, which improves the rate of heat transfer by roughly 10% when compared to the case of the base fluid. [ABSTRACT FROM AUTHOR]