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With the escalating demand for advanced and eco-friendly processing technologies in mining engineering, the potential applications of microwave heating technology in the treatment of cement tailings backfill (CTB) are expanding significantly. This research comprehensively investigates the mechanisms through which microwave irradiation duration and power influence the mechanical properties of CTB with varying concentrations and cement-to-sand ratios. The aim is to reveal the influencing patterns through experimental methods, providing scientific evidence for optimizing CTB treatment processes. This paper conducted microwave heating tests, uniaxial compression tests, and SEM-EDS tests on CTB. The research results indicate that heating time and power significantly enhance the early strength of CTB, with a more pronounced effect on CTB with higher concentrations and higher cement–sand ratios. When the heating time is 7 min and the heating power is 340 W, the cement hydration reaction is maximally promoted, thereby increasing the density and strength growth rate of CTB. However, excessively long heating time or overly high heating power may cause microcracks or thermal stress concentration within the CTB, adversely affecting the strength growth rate of CTB. Optimal thermal exposure duration and microwave power settings facilitate the activation of cementitious materials and the nucleation of calcium-silicate-hydrate (C-S-H) phases, thereby accelerating the compressive strength evolution of cemented tailings backfill (CTB). The outcomes of this research offer valuable insights into the deployment of microwave heating methodologies in underground mine backfilling, which are pivotal for augmenting the economic viability and environmental sustainability of mining operations. [ABSTRACT FROM AUTHOR]

Heat–moisture treatment (HMT) is a widely used method for modifying starch properties with the potential to reduce the digestibility of high-amylose starch (HAS). This study aimed to optimize the HMT conditions for HAS and apply the resulting HMT-HAS to triticale noodles to develop low-glycemic-index products. HMT significantly increased the resistant starch (RS) content and decreased the rapidly digestible starch (RDS) content of HAS. The treatment conditions—temperature, heating time, and moisture content—were found to significantly influence the starch composition. Optimal HMT conditions were determined using response surface methodology: a temperature of 108 °C, a heating time of 5.8 h, and a moisture content of 25.50%. Under these conditions, the RS content of HMT-HAS was 60.23%, nearly double that of the untreated sample. Increasing the level of HMT-HAS in triticale noodles led to significant decreases in short-range order, relative crystallinity, and viscosities, while the RS content increased from 12.08% to 34.41%. These findings suggest that incorporating HMT-HAS into triticale noodles effectively enhances starch digestive resistance, supporting the development of functional, low-glycemic-index triticale-based foods. [ABSTRACT FROM AUTHOR]

The T6 condition of AA7075 gives the highest elastic strength and ultimate strength of this alloy. To ensure that this condition is obtained at the end of the warm forming process, it is necessary to control the forming temperature (typically 200 ∘ C) to avoid any evolution of precipitates and consequent changes in mechanical behaviour. The aim of this work is to determine the optimal warm heating conditions for AA7075 to maintain the T6 state at the end of the forming. To find these parameters, several heating, temperature holding and cooling conditions used during multi-step warm forming are reproduced on a Gleeble machine. Vickers hardness and conductivity measurements, as well as tensile tests, are then carried out to check that this aluminum alloy still complies with the values of the T6 state standard values. A holding time of 10 s, with a fast heating rate of 250 ∘ C/s, and a cooling by air quenching prevent the development of precipitates and help to maintain the T6 state. These optimum conditions are finally validated using a multi-step warm forming process of a U-channel part. [ABSTRACT FROM AUTHOR]

With regard to the heating technology of small test specimens (D < 1 inch, i.e., 25.4 mm), only a limited amount of data and literature are available for making adequate technological decisions. Heating time of small geometric shapes is influenced by the technological parameters of the furnace, the temperature, the disposition technique in the furnace and the geometric characteristics of the workpiece. How to shorten heating time to achieve a suitable material structure is a vital question, while considerable energy is saved at the same time. Among the geometric characteristics, shape dependence is one of the important aspects that must be taken into account in terms of heating technology. Shape dependence is usually taken into account with empirically produced correction factors, which can result in significant oversizing of heating time, energy-wasting technology and material structure of insufficient fineness. In the course of our work, we investigated and compared the shape dependence of cylindrical and prismatic specimens with the same surface-to-volume ratios, which were combined with surface heat transfer analyses and geometric effect tests to formulate new approximate equations for determining heating time. As a result, we could mathematically derive a relationship between heating time, size and shape of the active surfaces, the correlation of which can shorten heating time by 20%. In addition, a shape factor (1.125) between cylinder and prismatic-shaped specimens was determined, which can be used with the new equation to calculate heating time for similar specimens. At last, a relationship is developed between the amount of heat that can be stored in the body during heat equalization and the complexity of the shape, which can be characterized through ratios depending on heating times and active surfaces in the function of total surface/volume ratio. Based on this relationship it can be determined more precisely when heat equalization occurs; therefore, shorter heating time can be achieved. In conclusion, with the help of this new method, optimal heating time for structural steel components, in the case of small cross-section and weight, can be determined. [ABSTRACT FROM AUTHOR]

Asphalt pavements are prone to cracking in low-temperature environments, and microwave heating (MH) can heal the cracks effectively. This research mainly investigates the different MH effects on the self-healing properties of asphalt mixtures. With this objective, the three-point splitting test is conducted to generate the cracks. A microwave oven is employed to heat the samples, and a thermal camera measures the surface temperature. Results indicate that heating power and time show a positive linear correlation with healing efficiency, and the HI of the samples can reach over 80%. The HI of the samples decreases with the heating cycle, but the sample with reasonable power and time still has a HI higher than 70% after 5 cycles. The temperature peaks on thermal images indicate that uneven heating exists during heating, but the heating uniformity is within an acceptable range. The healing efficiency level (HEL) suggests that asphalt mixtures have very low inefficient healing behavior if the heating time is below 45 s, but HEL can reach 86.14% at 700 W after 60 s. Furthermore, although the HI of strength shows ideal results, the recovery of other crack parameters, including stiffness, fracture energy, flexible index, and crack resistance index, are not satisfactory. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Synthetic Fiber Industry is the property of Sinopec Baling Petrochemical Company and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Heat–moisture treatment (HMT) is a widely used method for modifying starch properties with the potential to reduce the digestibility of high-amylose starch (HAS). This study aimed to optimize the HMT conditions for HAS and apply the resulting HMT-HAS to triticale noodles to develop low-glycemic-index products. HMT significantly increased the resistant starch (RS) content and decreased the rapidly digestible starch (RDS) content of HAS. The treatment conditions—temperature, heating time, and moisture content—were found to significantly influence the starch composition. Optimal HMT conditions were determined using response surface methodology: a temperature of 108 °C, a heating time of 5.8 h, and a moisture content of 25.50%. Under these conditions, the RS content of HMT-HAS was 60.23%, nearly double that of the untreated sample. Increasing the level of HMT-HAS in triticale noodles led to significant decreases in short-range order, relative crystallinity, and viscosities, while the RS content increased from 12.08% to 34.41%. These findings suggest that incorporating HMT-HAS into triticale noodles effectively enhances starch digestive resistance, supporting the development of functional, low-glycemic-index triticale-based foods.

Thermal treatment of pine wood was carried out at 80, 120, 160, and 200 °C for 2, 4, and 6 hours. The highest mean values were, for specific gravity (0.492), moisture content (29.1%), and maximum moisture content (191%), whereas the lowest mean values were for specific gravity (0.418), moisture content (1.20%), and maximum moisture content (127%). The maximum mean values were for shrinkage in longitudinal plane (0.42%), radial plane (4.63%), volumetric shrinkage (9.28%), and maximum mean value tangential plane (3.67%). The minimum mean values were for shrinkage in longitudinal plane (0.04%), radial plane (2.22%), tangential plane (1.55%), and volumetric shrinkage (4.88%). Maximum mean values were for swelling in longitudinal (0.41%), radial (5.22%), and tangential plane (3.15%) and maximum mean volumetric swelling (7.71%), while minimum mean values were for swelling in longitudinal plane (0.08%), radial plane (2.26%), and tangential plane (1.29%) and minimum mean volumetric swelling (3.15%). The highest mean values were for tensile strength (57.3 MPa) and compression parallel to the grain (50.3 MPa), the maximum mean value of bending strength (84 MPa) and compression strength perpendicular to grain (27 MPa), whereas the lowest values were for tensile strength (42.7 MPa), bending strength (7.33 MPa), compression parallel to the grain (7.33 MPa) and compression strength perpendicular to grain (12.3 MPa).

In this paper, the temperature field variation and cumulative oil production rate over time with fracture number, fracture width and gas injection flow rate were investigated using Fluent software. A mathematical model of heat transfer within oil shale and a three-dimensional mathematical model of its in situ heating and fracturing were established. The simulation results showed that Model II had the highest oil shale heating rate at different fracture numbers, being 26.32% higher than that of Model I. When exploring fracture width, Model I completed all fractures in the oil shale region in 190 days. Model IV was 15 days slower than Model I with the heating rate being 7.89% lower, while Model V was 10 days faster than Model I with the heating rate being 5.26% higher. Increasing the fracture width of the oil shale region appropriately could help to increase the oil shale in-situ heating and fracturing rate. Considering gas injection flow rate, the higher the gas flow rate, the faster the increase of the oil shale area temperature and the shorter the time to reach the 10-day peak oil production rate. The peak was also larger and the fracturing of the oil shale area took place more quickly.

At the Pervouralsk New Pipe Plant, in collaboration with the staff of the Ural Federal University, a technological scheme for the production of capillary tubes used for manufacturing disposable medical syringes was developed and implemented. To achieve the desired tube size, the tubes undergo drawing, followed by annealing in a continuous electric furnace with a protective atmosphere to relieve stress. To optimize the annealing process of the tubes, thermal losses were determined based on heat engineering calculations, which allowed for the optimization of furnace power. A calculation of heating elements was performed, determining the diameter and total length of the wire heaters. A method for calculating the heating time of thin bodies for capillary tubes of a given size was substantiated. Based on the constancy of the temperature in the furnace's working space and heat transfer primarily by radiation, the heating time for capillary tubes of different diameters was determined. When blowing tubes with various gases, pressure losses were calculated for tubes of different diameters and lengths. Temperature fields inside the muffles, through which the capillary tubes move, were investigated. The obtained results are of interest to technologists and can be useful in developing technological schemes for the production of capillary tubes for manufacturing medical needles. [ABSTRACT FROM AUTHOR]

Ammonium bisulfate (ABS; NH4HSO4) and ash blend deposition endanger the boiler's safety by blocking and corroding air preheater in coal‐fired power plants. In this work, a self‐heating probe was used to investigate the decomposition characteristics of ABS and fly ash blend deposition after heating at 365°C for 5, 15, and 30 min. The results showed that after heating for 15 min, ash deposition was peeled off from the probe surface. When it came to 30 min, the metal surface of the probe could be seen. Scanning electron microscope (SEM) results showed that extending the heating time could alleviate the agglomeration of ash particles. After the deposition stage, the stable relative heat flux density was about 0.868, and it increased after heating. When the heating time was 5, 15, and 30 min, it was 0.954, 0.978, and 0.989, respectively. According to X‐ray diffraction (XRD) results, the main minerals in the deposition were quartz, mullite, tschermigite (NH4Al(SO4)2·12H2O), CaSO4, ammonium sulfate (AS; (NH4)2SO4), ABS, (NH4)3Al(SO4)3, and godovikovite (NH4Al(SO4)2). The thermal gravimetric analyzer (TGA) results indicated that after heating, the total content of ABS and AS in cases 1 ~ 4 was 2.03%, 1.33%, 0.75%, and 0.70%, respectively. This work can assist in air preheater design and ash deposition removal. [ABSTRACT FROM AUTHOR]

This article presents novel research on the utilization of a neural-network-based time control system for microwave oven heating of food items within a solar-powered vending machine. The research aims to explore the control of heating time for various food products, considering multiple variables. The neural network controller is calibrated through extensive experimentation, allowing it to accurately predict optimal heating times based on input parameters such as food type, weight, initial temperature, water content, and desired doneness level. The results demonstrate that the neural-network-controlled microwave oven achieves precise and desirable heating durations, mitigating the risk of overheating and ensuring superior food quality and taste. Moreover, the solar-powered vending machine showcases a commitment to sustainable energy sources, effectively reducing dependence on non-renewable energy and minimizing greenhouse gas emissions. To maintain food quality and freshness, a food refrigeration unit is integrated into the vending machine, employing load-balancing technology to control the refrigeration chamber's temperature effectively. Energy efficiency is prioritized in both the refrigeration unit and the microwave oven through intelligent algorithms and system optimization. The combination of a neural-network-controlled microwave oven, a solar-powered vending machine, and a food refrigeration unit introduces a novel and sustainable approach to food preparation and energy management. [ABSTRACT FROM AUTHOR]

Thermal treatment of pine wood was carried out at 80, 120, 160, and 200 °C for 2, 4, and 6 hours. The highest mean values were, for specific gravity (0.492), moisture content (29.1%), and maximum moisture content (191%), whereas the lowest mean values were for specific gravity (0.418), moisture content (1.20%), and maximum moisture content (127%). The maximum mean values were for shrinkage in longitudinal plane (0.42%), radial plane (4.63%), volumetric shrinkage (9.28%), and maximum mean value tangential plane (3.67%). The minimum mean values were for shrinkage in longitudinal plane (0.04%), radial plane (2.22%), tangential plane (1.55%), and volumetric shrinkage (4.88%). Maximum mean values were for swelling in longitudinal (0.41%), radial (5.22%), and tangential plane (3.15%) and maximum mean volumetric swelling (7.71%), while minimum mean values were for swelling in longitudinal plane (0.08%), radial plane (2.26%), and tangential plane (1.29%) and minimum mean volumetric swelling (3.15%). The highest mean values were for tensile strength (57.3 MPa) and compression parallel to the grain (50.3 MPa), the maximum mean value of bending strength (84 MPa) and compression strength perpendicular to grain (27 MPa), whereas the lowest values were for tensile strength (42.7 MPa), bending strength (7.33 MPa), compression parallel to the grain (7.33 MPa) and compression strength perpendicular to grain (12.3 MPa). [ABSTRACT FROM AUTHOR]

Effects of thermal modification were determined relative to chemical parameters of Pinus roxburghii. Thermal modification of wood was carried out at 80, 120, 160, and 200 °C for 2, 4, and 6 h. The chemical properties were different for different temperatures and different heating time. All parameters were similar except for cold water soluble extractives. Among the chemical properties studied, the maximum mean value of cold water extractives (8.20%), hot water soluble extractives (12.7%), holocellulose content (71.8%), and ash content (1.46%) were recorded at 120 °C, whereas the maximum mean values of alcohol benzene soluble extractives (13.9%) and lignin content (33.7%) were observed at 200 °C. The minimum mean value of cold water soluble extractives (5.82%), hot water soluble extractives (9.27%), holocellulose content (65.8%), and ash content (1.03%) were found to be at 200 °C, while the highest value of alcohol benzene soluble extractives 12.2% (control) and lignin content (28.0%) were found to be at 80 °C.

Asphalt pavements are prone to cracking in low-temperature environments, and microwave heating (MH) can heal the cracks effectively. This research mainly investigates the different MH effects on the self-healing properties of asphalt mixtures. With this objective, the three-point splitting test is conducted to generate the cracks. A microwave oven is employed to heat the samples, and a thermal camera measures the surface temperature. Results indicate that heating power and time show a positive linear correlation with healing efficiency, and the HI of the samples can reach over 80%. The HI of the samples decreases with the heating cycle, but the sample with reasonable power and time still has a HI higher than 70% after 5 cycles. The temperature peaks on thermal images indicate that uneven heating exists during heating, but the heating uniformity is within an acceptable range. The healing efficiency level (HEL) suggests that asphalt mixtures have very low inefficient healing behavior if the heating time is below 45 s, but HEL can reach 86.14% at 700 W after 60 s. Furthermore, although the HI of strength shows ideal results, the recovery of other crack parameters, including stiffness, fracture energy, flexible index, and crack resistance index, are not satisfactory.

Recovering useful materials from agricultural waste into electronic materials remains challenging. SiO2 nanoparticles were successfully extracted from rice straw ash by a sol–gel process. Then, magnesiothermic reduction with various heating times was employed to form the Si phase. The phase, structure and photoluminescence were investigated by different analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) and photoluminescence spectroscopy (PL). With a 2 h reduction process, an incomplete phase change from SiO2 to Si was found in terms of the SiO2/Si composite, whereas the SiO2/Si/Mg2SiO4 composite formed at 3 h. A dense agglomeration of irregularly shaped nanoparticles was observed when the magnesiothermic process was extended to 3 h. The photoluminescence excitation spectra show different emissive energies at approximately 425 nm (blue), 540 nm (green), and 700 nm (red), confirming the formation of SiO2, Si, and oxygen defects, respectively. A chromaticity diagram by the Commission Internationale de I'Eclairage (CIE) reveals a blue emission for SiO2, which develops to a yellow emission in SiO2/Si and SiO2/Si/Mg2SiO4 composites. Owing to their cost advantage, the obtained composites have the potential to be applied in optical functions. [ABSTRACT FROM AUTHOR]

Effects of thermal modification were determined relative to chemical parameters of Pinus roxburghii. Thermal modification of wood was carried out at 80, 120, 160, and 200 °C for 2, 4, and 6 h. The chemical properties were different for different temperatures and different heating time. All parameters were similar except for cold water soluble extractives. Among the chemical properties studied, the maximum mean value of cold water extractives (8.20%), hot water soluble extractives (12.7%), holocellulose content (71.8%), and ash content (1.46%) were recorded at 120 °C, whereas the maximum mean values of alcohol benzene soluble extractives (13.9%) and lignin content (33.7%) were observed at 200 °C. The minimum mean value of cold water soluble extractives (5.82%), hot water soluble extractives (9.27%), holocellulose content (65.8%), and ash content (1.03%) were found to be at 200 °C, while the highest value of alcohol benzene soluble extractives 12.2% (control) and lignin content (28.0%) were found to be at 80 °C. [ABSTRACT FROM AUTHOR]

Homogeneous fruit juice in a sealed container available in the commercial market exhibits some degree of non-Newtonian behavior with a wide viscosity range. During thermal processing, it is necessary to understand the effect of viscosity on thermal behavior, which may guide insight into the choice of physics involved in the conservation law equations. In this context, the present study considered the Carboxyl Methyl Cellulose (CMC) solutions (a viscosity-enhancing agent) as model foodstuffs to understand the effect of viscosity on the heat transfer mechanism in the thermal treatment of canned liquid products. Computational Fluid Dynamics (CFD) was employed to analyze the thermal behavior of different concentrations of CMC solutions, estimated based on averaged wall heat flux, averaged heat transfer coefficient, volume-averaged temperature, and minimum temperature. The effect of the CMC solutions' rheological properties on the thermal behavior was evaluated by comparing it with the pure conduction simulations. The time–temperature history obtained from the simulations was coupled with the kinetic parameter of microbial destruction to predict the heating time. When the viscosity increases due to increasing the concentration of CMC solution, the natural convection is suppressed, which leads to the heat transfer in almost pure conduction mode.

Aiming at the problems of real-time monitoring of the temperature of the heat source in the goaf and accurate positioning of the high-temperature point, the temperature variation law of the high-temperature heat source in the goaf model is studied by using the non-contact infrared temperature measuring device. The relationship between heat source temperature, heating time, temperature measured by sensor and temperature measurement distance is analyzed, and the equation of heat source location under ideal conditions is deduced. Based on the heat source temperature change rate, the heat source temperature time piecewise fitting model and the sensor measured temperature iterative compensation model correct the fitting error of the data and the systematic error of the device. The results show that the temperature of the heat source changes as a quadratic function with the heating time, and the heating rate of the heat source increases first and then decreases; the temperature measured by the sensor is directly proportional to the temperature of the heat source, and the temperature receiving rate of the sensor is inversely proportional to the temperature measurement distance; the maximum relative error of the corrected heat source temperature is 0.48%, and the average absolute error of the temperature measurement distance is 0.1 m.

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article presents novel research on the utilization of a neural-network-based time control system for microwave oven heating of food items within a solar-powered vending machine. The research aims to explore the control of heating time for various food products, considering multiple variables. The neural network controller is calibrated through extensive experimentation, allowing it to accurately predict optimal heating times based on input parameters such as food type, weight, initial temperature, water content, and desired doneness level. The results demonstrate that the neural-network-controlled microwave oven achieves precise and desirable heating durations, mitigating the risk of overheating and ensuring superior food quality and taste. Moreover, the solar-powered vending machine showcases a commitment to sustainable energy sources, effectively reducing dependence on non-renewable energy and minimizing greenhouse gas emissions. To maintain food quality and freshness, a food refrigeration unit is integrated into the vending machine, employing load-balancing technology to control the refrigeration chamber’s temperature effectively. Energy efficiency is prioritized in both the refrigeration unit and the microwave oven through intelligent algorithms and system optimization. The combination of a neural-network-controlled microwave oven, a solar-powered vending machine, and a food refrigeration unit introduces a novel and sustainable approach to food preparation and energy management.

In order to explore the effect of heating method and heating time on physicochemical properties of fish gelatin, the protein composition, viscosity, rheological properties and thermal stability of heated gelatin solutions, and the gel strength, texture profile analysis (TPA) parameters and microstructure of gelatin gels were analyzed and compared. The results showed that the viscosity, rheological properties and thermal stability of fish gelatin solutions decreased significantly with the increase of heating time, while the change extents of these properties in the intermittent heated gelatin were less than those in the continuous heated gelatin. When gelatin was heated for 48 h continuously, the β band disappeared in the electrophoresis pattern, and the α1 and α2 subunits degraded obviously after being heated for 96 h. When gelatin was heated for 96 h intermittently, the β band disappeared. The gel strength and TPA parameters of the gel prepared by fish gelatin gradually decreased with the increase of heating time, whereas the gel properties of the intermittent heated gelatin were superior to those of the continuous heated gelatin. Scanning electron microscope results showed that the surfaces of continuous heated gels were smooth and flat, while the structure of gel prepared by intermittent heated gelatin was rougher and more porous. The results suggested that intermittent heating and the heating less than 12 h could reduce the heat degradation of gelatin.

The deep geological disposal has been considered as safe and effective way to dispose high-level radioactive nuclear waste internationally. When nuclear waste is sealed in the repository, it will continue to decay and release a large amount of decay heat, and therefore, the bentonite used as a buffer/backfill layer in the repository will remain in a high temperature state for a long time. After experiencing continuous high temperature, whether the hydro-mechanical behaviour of bentonite will change significantly needs to be resolved. In this paper, the swelling, shrinkage and water retention behaviour of compacted MX80 bentonite experiencing different heating times at temperature of 200 °C were investigated by the swelling pressure, shrinkage and vapour equilibrium technique, together with the thermogravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscopy (SEM) tests. The test results show that with increasing the heating time, the swelling and shrinkage indexes (swelling pressure, free swelling rate, shrinkage limit, and shrinkage coefficient) dropped sharply in the first 15–30 days, after that the indexes changed very little. In addition, the total reduction rates in the swelling pressure, free swelling rate, shrinkage limit, and axial shrinkage coefficient of MX80 bentonite experiencing 0 to 120 days heating are 35.4, 45.1, 49.8 and 25.5%, respectively. After experiencing high temperature of 200 °C, the main mineral montmorillonite in the MX80 bentonite was partially transformed into a low-swelling mineral paragonite from the XRD test results. From the TGA test results, the adsorbed water content decreased first and then remained unchanged with increasing the heating time, and the total reduction rates of free water, strong and weak bound waters were 82.5, 68.8 and 96.5%, respectively. From the SEM test results, the high temperature caused the layered structure to shrink and become tighter. [ABSTRACT FROM AUTHOR]

[Display omitted] • The viscous effect was examined systematically on the thermal behavior. • When the natural convection is suppressed, it leads to the conduction mode. • As viscosity rises, the convective heating time approaches the conduction heating time. • Conduction simulation may capture the thermal behavior of the highly viscous fluid. Homogeneous fruit juice in a sealed container available in the commercial market exhibits some degree of non-Newtonian behavior with a wide viscosity range. During thermal processing, it is necessary to understand the effect of viscosity on thermal behavior, which may guide insight into the choice of physics involved in the conservation law equations. In this context, the present study considered the Carboxyl Methyl Cellulose (CMC) solutions (a viscosity-enhancing agent) as model foodstuffs to understand the effect of viscosity on the heat transfer mechanism in the thermal treatment of canned liquid products. Computational Fluid Dynamics (CFD) was employed to analyze the thermal behavior of different concentrations of CMC solutions, estimated based on averaged wall heat flux, averaged heat transfer coefficient, volume-averaged temperature, and minimum temperature. The effect of the CMC solutions' rheological properties on the thermal behavior was evaluated by comparing it with the pure conduction simulations. The time–temperature history obtained from the simulations was coupled with the kinetic parameter of microbial destruction to predict the heating time. When the viscosity increases due to increasing the concentration of CMC solution, the natural convection is suppressed, which leads to the heat transfer in almost pure conduction mode. [ABSTRACT FROM AUTHOR]

Aspects of regenerative heat exchange in a piston compressor are investigated. The most thermodynamically advantageous situation occurs when compression approaches an isothermal process. The heat balance equation, which compares the amount of heat released per piston compressor cycle and that removed through the outer surface of the working chamber, was used to develop a method for calculating heat absorbed by working chamber walls in a compressor depending on the duration of compressor operation. The developed procedure provided a basis for parametric analysis to determine the influence of the main operating parameters (pressure ratio in a stage, angular velocity of crankshaft rotation) on the final temperature and heating time of the walls. This procedure can be used for preliminarily estimating the operating time of a piston machine employing regenerative cooling in compressor mode. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum Polonorum: Architectura is the property of Wydawnictwo SGGW and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, the performance improvement of an electric injera baking stove is studied experimentally using copper powder as additive material for baking plate preparation. The performance of conventional electric injera baking stove is low because of the poor thermal conductivity of the backing plate material. This leads to a high energy consumption ranging from 1.23 to 1.41 kWh for initial heating and observed uneven temperature distribution on the baking surface. Therefore, this study focuses on reducing the time required for initial heating so that the energy consumption will be reduced which will result in overall thermal efficiency improvement. The composite material is developed in four different samples with mixture of different ratios of clay soil and copper powder. Then the performance is studied experimentally. The experiments are conducted for analyzing the initial heating time, plate surface temperature distribution and energy consumption. The results show that the composite material thermal conductivity property has been improved due to addition of copper powder. The sample with 20% copper powder and 80% clay soil ratio mixture has given a better overall performance than other composition (i.e. less initial heating time, better uniform baking surface temperature and less energy consumption/kg of injera). The thermal efficiency of the improved baking stove is 88.55% which is of Grade 1 as per the Ethiopian Standard 'ES 04090 sub article 4.2 while that of the conventional electric baking stove is 53.36%. Hence, the addition of copper powder to clay has resulted in an overall improvement in thermal efficiency. The quality of injera baked is also very nice with bubbly eye in the front and smooth back side. • Thermal efficiency of electric Injera baking stove • Composite material for electric Injera baking plate • Copper powder as additive material for improving Injera baking plate efficiency • Minimize electric heating-up time to reduce consumption and improve efficiency [ABSTRACT FROM AUTHOR]

The application of chemical analysis on bituminous materials has increased drastically over the past decades. One of the most common spectroscopic methods used in the field of research is Attenuated Total Reflection (ATR) Fourier Transform Infrared (FTIR) spectroscopy. Since ATR-FTIR is a surface sensitive method, sample or specimen handling of a complex material like bitumen prior to its analysis needs to be considered, especially for people new to the field or analysis technique. This study looks at the impact of heating time and temperature as well as storage time and conditions on the oxidation of the bituminous specimen. Four binders from the same crude oil source but different specification classes (unmodified and styrene–butadiene–styrene polymer modified) and two binders from different crude oil sources were investigated. The results show that heating small quantities of bitumen at 180 °C for up to 30 min has little impact on the formation of oxidized species, when proper thermal monitoring is conducted. Special cases where oxidation does occur are reported in detail. Furthermore, strong oxidation is induced by day light, when bitumen is stored behind glass with no UV radiation present, which can reach short-term ageing level within 1 h. Thus, heating bitumen at 180 °C for 5–10 min followed by storage in the dark, climatized room and measured within one hour after preparation is recommended. These results should act as recommendation for future specimen handling prior to FTIR spectroscopic analysis to ensure unbiased and comparable measurements. [ABSTRACT FROM AUTHOR]

Deep and ultra-deep layers in the petroliferous basins of China are characterized by large temperature difference and complicated thermal evolution history. The control effects of temperature and thermal evolution history on the differences of hydrocarbon phase states and the hydrocarbon generation history in deep and ultra-deep layers are researched less and unsystematically. To deal with this situation, based on a large number of temperature and pressure data of deep layers and combined with the complicated historical situation of deep layer evolution in the oil and gas basins of China, the effects of temperature, heating time and pressure on the hydrocarbon formation temperature and phase state were analyzed, and the types of temperature and pressure relationships were classified. Finally, based on the classification of thermal evolution history of deep and ultra-deep layers, We discussed the control effects of basin thermal evolution history on the hydrocarbon generation and phase state, and the following research results were obtained. First, the hydrocarbon phase states of deep layers in different basins and regions are greatly different, and they are mainly affected by temperature, heating time, heating rate, pressure, source rock types and other factors. And temperature is the most important factor controlling hydrocarbon generation and phase state distribution. Second, under the conditions of rapid temperature increasing and short heating time, there still may be oil reservoirs and condensate gas reservoirs in deep and ultra-deep layers in the case of high temperature. Third, overpressure inhibits hydrocarbon generation and pyrolysis. Fourth, there is a close relationship between temperature and formation pressure of deep layers, which can be divided into three types, i.e., low–medium temperature and high pressure type, high temperature and high pressure type, and medium temperature and low–medium pressure type. Fifth, the thermal evolution history of deep and ultra-deep layers can be divided into four types, namely the late rapid subsidence, heating and low geothermal gradient type, the late rapid subsidence, heating and high geothermal gradient type, the middle–late rapid heating and late uplifting and cooling type, and the early great subsidence and rapid heating and middle–late great uplift erosion and cooling type. In conclusion, deep and ultra-deep layers in the basins with different types of thermal history are different in hydrocarbon phase states, accumulation stages and prospects.

A laminated mouthguard is made by fusing sheets of mouthguard materials together. Adequate adhesive strength is required to use mouthguards in stable condition for a long time. To date, adhesive strengths have been investigated on a flat surface. However, an actual mouthguard is made on a player's model with different inclination. Therefore, in this study, the exfoliation test was applied to determine the adhesive strength during thermoforming using a special simulation model with three different flat surfaces of 0 degree, 45 degrees, and 90 degrees against a pressurizing force. Air pressure type samples were made by EVA blank. Samples were laminated with two pieces of mouthguard material and cut out with an adhesive area of 5 × 5 mm2, the other end was the holding part. Three different heating times of 100, 115 and 130 s were employed. The delamination test was carried out by employing Autograph. Original jigs with screws were used to grip the specimen firmly. Adhesive strength was measured at the center of the 0-degree and 45-degree surfaces, and upper and lower positions on 90-degree surface. The result was measured at the time of breakage of the maximum load, and the form of destruction was examined. At a heating time of 100 seconds, all four surfaces showed interface failures. The 0-degree surface showed the largest failure load, and the greater inclination and lower measuring position of a 90-degree surface reduced the adhesive strength significantly. At a heating time of 115 seconds, the 0-degree surface showed material failures. The other three surfaces showed interface failures and the greater inclination and lower measuring position of a 90-degree surface reduced the adhesive strength significantly. At a heating time of 130 seconds, all four surfaces showed material failures; these failures do not represent adhesive strength, but material thickness after thermoforming. [ABSTRACT FROM AUTHOR]

This work presents two-dimensional numerical investigations of fast pyrolysis of red oak in a free fall reactor. The Euler-Lagrange approach of multiphase flow theory was proposed in order to describe the behaviour of solid particles in the gaseous domain. The main goal of this study was to examine the impact of the flow rate of inert gas on the pyrolysis process. Calculation domain of the reactor was made according to data found in the literature review. Volume flow rates were 3, 9, 18, and 25 l/min, respectively. Nitrogen was selected as an inert gas. Biomass pyrolysis was conducted at 550°C with a constant mass flow rate of biomass particles equal to 1 kg/h. A parallel multistage reaction mechanism was applied for the thermal conversion of red oak particles. The composition of biomass was represented by three main pseudo-components: cellulose, hemicellulose and lignin. The received products of pyrolysis were designated into three groups: solid residue (char and unreacted particles), primary tars and noncondensable gases. In this work the impact of the volume flow rate on the heating time of solid particle, temperature distribution, yields and char mass fraction has been analysed. The numerical solutions were verified according to the literature results when the flow of nitrogen was set at 18 l/min. The calculated results showed that biomass particles could be heated for longer when the flow rate of nitrogen was reduced, allowing for a greater concentration of volatile matter. [ABSTRACT FROM AUTHOR]

In wood processing, wood is exposed to an environmental temperature of less than 0 °C for some time, which mainly occurs during the air drying of wood in the winter months, or when lumber is stored in wood piles outdoors before the kiln drying process. In these cases, the wood freezing process increases the degree of freezing of the wood, subsequently significantly affecting the process of its heating during further processing (for example, in the cutting process). The most common method is heating by humid air, during the hot air drying of wood. We analyzed the temperature profiles on a cross-section of wood and moisture losses due to the freezing process and the size of moisture gradients. We compared theoretical calculations of the time required for defrosting and heating of wood with the experimentally measured values. The results show that the moisture content (MC) of wood has a remarkable effect on the wood freezing process. In samples with an average MC of 35.47%, the temperature drop was faster. After 10 h, the temperatures on the entire cross-section of the samples reached the lowest value of −13.2 °C. In samples with an average initial MC of 81.38%, three stages of temperature reduction in the wood were observed. The temperature dropped and the lowest temperature of −20.11 °C was reached after 24 h. The defrosting and heating process of samples with lower MC was significantly easier. The desired temperature of 65 °C in the middle of the samples was reached in 2 h and 20 min. The total time to defrost and heat the second group of samples (MC > FSP) was 3 h 30 min. [ABSTRACT FROM AUTHOR]

Through decades of research and development efforts, Microwave Assisted Thermal Sterilization (MATS) systems started commercial operation for production of shelf-stable meals in 2019. It is now highly desirable to develop user-friendly tools to facilitate the development of commercial MATS processes. The aim of this research was to develop engineering charts by applying Maxwell's and heat transfer equations to illustrate the relationships among dielectric properties, temperature, salt content, product thickness and heating rate for microwave heating in a MATS system. Three G-T (Gezahegn-Tang) charts were developed for mashed potato, peas, and rice products with MATLAB software. The charts can be used to determine the heating temperature, time and optimum salt content for a maximum heating rate at the center of a product. Experimental validation tests using mashed potato samples confirmed that the temperature profiles measured at the cold spots of the samples in the microwave heating section of the MATS system were positively correlated with predicted temperatures from the chart (R2 = 0.94–0.99). Furthermore, the predicted optimal salt contents for 23 mm thick mashed potato (0.1%), 18 mm thick pea (0.5%) and 25 mm thick rice (1%) samples agreed with the experimental heating pattern test results. The optimal salt content is inversely proportional with a product temperature and thickness, which increases the microwave power decay before reaching the center. With the help of these charts, the food industry practitioners can save significant time and resources during the development of food products and schedules for the MATS processes. • Engineering charts were developed for selected products in the MATS. • The heating rate of the samples were accurately determined with the charts. • The required sterilization heating time can be estimated accurately. • The charts are useful in determining the optimal salt content. • The charts can significantly save time and resources in MATS process development. [ABSTRACT FROM AUTHOR]

The determination of oil physicochemical properties is a useful strategy to monitor oil quality to avoid the use of potentially toxic oil. It is relevant in determining the physical and chemical changes that oil undergo during heating. In this work, the effect of prolong heating time from 1–7 h on the physicochemical properties of soybean oil, palmolein oil, groundnut oil and palm kernel oil was examined. Properties such as specific gravity, viscosity, saponification value (SV), iodine value (IV), free fatty acid and peroxide value (PV) were studied to evaluate the compositional quality of oils. Results revealed that heating at the different times did not have any significant effect on the physicochemical properties of the oils. There was however, significant differences of the physicochemical properties on the oil types. Results further reveal that based on the peroxide value, soybean oil was the most stable oil out of the four oils studied while palm kernel oil was found to be the least stable oil; as the stability of palm olein oil was found greater than that of groundnut oil.

Although the urban environment pollution is decreased by electric buses, the driving range is still a problem for the electric car. Especially, there is a dramatic decline in driving range while heating the electric bus cabin in winter. To solve this problem, the authors propose an eddy‐current braking and heating system. The braking energy is converted to thermal energy directly by the electromagnetic method. The energy conversion efficiency of the system is higher than that of the regenerative braking system. A braking energy management control strategy based on fuzzy control is proposed. A dynamic programming algorithm is simulated and analysed by extracting the design parameters. In the MATLAB/Simulink environment, the authors build a simulation platform for calculating efficiency. Compared with the normal strategy, the proposed fuzzy braking strategy can improve 9.8% of the electricity consumption. The heating time of the bus cabin to reach 20°C by the proposed strategy is only 60 s, whereas it is 700 s by the normal strategy. [ABSTRACT FROM AUTHOR]

The development of electric vehicles is an important trend in the automotive industry, in which the performance of power batteries is greatly affected by temperature. In recent years, it has been widely concerned that the performance of power batteries at low temperature will lead to the vehicle failure to start because of the bad thermal equilibrium of power battery heating system. This paper studies the thermal equilibrium performance of battery liquid heating system at low temperature. Inlet temperature, heating time, ambient temperature, and their coupling relationship to battery thermal equilibrium performance are studied by orthogonal experimental design method. It is expected that this study can provide reference for the parameter selection of battery heating system. [ABSTRACT FROM AUTHOR]

Thermal-assisted machining (TAM) is an effective processing solution to improve productivity and product quality made from materials with high strength and hardness. This method is widely used in nonchip machining such as forging, stamping, deep drawing, etc. For the method of heating on the molds, it is possible to control local heat or uniform heat on the workpiece. However, the calculation of heat capacity, heat transfer as well as the heating time to achieve the temperature on the workpiece is necessary to design suitable molds and heating system. This study focuses on a heating system that uses single-sided thermostatic heating rods to heat the molds, verify the effect of the heating time on the temperature of the workpieces and then control the temperature on the workpieces at various heat levels through a heating control system. Thereby, this study proposes to build a mathematical model between temperature and heating time on the workpiece. [ABSTRACT FROM AUTHOR]

To obtain enough hardness of the die-quenched products after hot stamping using direct resistance heating, the effects of the electrifying condition and initial microstructure of the quenchable steel sheet on hardness were examined in a hot bending experiment. The steel sheet was heated up to 900 °C in 3 to 10 s. The required heating time was shortened by normalising heat treatment due to the fine grain size of the sheet. The standard deviation of the hardness of the sheet heated to 900 °C in 3.2 s without temperature holding at the austenitising temperature was 12 HV, whereas the deviation reduced to 5 HV for temperature holding at the austenitising temperature of 3 s. [ABSTRACT FROM AUTHOR]

The effect of the time and temperature on the weight loss ratio of oil shale was studied. Oil shale from an open-pit oil shale mine of Fushun in Liaoning Province, China was used. The results show that crack width, length and quantity, and the weight loss rate, increase with increased temperature. The fastest increase rate was between 400 ℃ to 600 ℃. The weight loss rate level tended to be flat when above 700 ℃, which means the change in the weight loss ratio is not obvious. In the process of oil shale pyrolysis, there is an optimal constant temperature time of about 8 hours. At this time, the big, medium and small cracks within the oil shale connect. When the number of cracks reaches its maximum, the weight loss ratio of the oil shale will also reach its maximum (21.67 %). The condition for the highest weight loss ratio of the sample shale oil occurred under a constant heating temperature of 600 ℃ for 8 hours. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Copyright of Wool Textile Journal is the property of National Wool Textile Science & Technology Information Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Highlights • New insights into starch gelatinization were provided in this study. • Gelatinization initiated earlier than onset temperature of DSC endotherm. • Longer heating caused greater structural disruption at high water content. • DSC endotherm does not represent fully behavior of starch gelatinization. Abstract In this study, the gelatinization behavior of wheat starch was investigated using starch-water mixtures that were heated under different conditions. Heating starch-water mixtures at 50 °C, a temperature below onset temperature (T o) of starch gelatinization, resulted in disruption of long- and short-range ordered structure, as measured by differential scanning calorimetry, X-ray diffraction and laser confocal micro-Raman spectroscopy, and the extent of disruption was greater when starch was heated at higher water content. At low water content (23–44%), heating duration had little effect on gelatinization behavior of starch, whereas at higher water content (54–75%), longer duration of heating resulted in greater disruption of multiscale structure of starch. From this study, we concluded that the gelatinization endotherm of starch does not represent the complete gelatinization behavior, and starch gelatinization initiates earlier than T o. Longer duration of heating caused a greater disruption of starch structure at high water content than at low water content. [ABSTRACT FROM AUTHOR]

In the present work, zinc oxide (ZnO) thin films were prepared by heating, at 500 ∘C, metallic Zn films deposited onto Si (100) substrates by RF magnetron sputtering. According to the x-rays diffraction patterns, the polycrystalline hexagonal ZnO phase (wurtzite) was obtained with a preferential orientation along the (101) planes. The increase of both the crystallites size and the Zn-O bond length, as a function of the heating time, reflect the improvement of the crystalline quality of the investigated films. The investigated films emitted in ultraviolet, visible and infrared regions. The ultraviolet emission was linked to the crystalline quality of the films. All the visible emission related defects were identified. Their concentrations vary differently as a function of the heating time. The infrared emission originated from the oxygen anti-sites (OZn). The correlation between the decrease of the electrical resistivity and the increase of both 2 + charged oxygen vacancies ( V O + +) and hydrogen impurities (H-I) defects suggested that the unintentional n-type conductivity in ZnO came from the collective contribution of V O + + and H-I defects. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Spectral emissivity of oxidized copper is studied. • Strong oscillatory behavior is found at four temperatures. • The interference effect and lattice oscillation of the oxide film are demonstrated to be the reason for the oscillation. Abstract The normal spectral emissivity of oxidized copper is measured by an experimental setup based on a Fourier transform infrared spectrometer (Bruker 70V) in the wavelength range of 3–20 μm at four temperatures (573 K, 673 K, 773 K, 873 K) during thermal oxidation. Normal spectral emissivity of the samples is obtained every ten minutes for 60 min while the samples are heated at each temperature. The influence of wavelength, temperature, and heating time on the normal spectral emissivity of pure copper during the oxidation process is analyzed. It was found that the spectral emissivity at 12 μm, 15 μm, and 17 μm remained constant for different heating times at 673 K. At the other three temperatures, the normal spectral emissivity demonstrated only a marginal increase with the increase of the heating time at the same wavelength. The oscillation of normal spectral emissivity of pure copper during oxidation was also found. At shorter wavelengths, the theory of radiation interference between the oxide layer and substrate is introduced to explain the spectral emissivity oscillation. In the long wavelength band, the lattice oscillation of the oxide film is used to explain the spectral emissivity oscillation. To better understand these phenomena and the radiative properties of pure copper during thermal oxidation process, the X-ray diffraction, scanning electron microscope and evaluation of surface roughness were performed to describe the compositions and surface micromorphology of the oxide film. [ABSTRACT FROM AUTHOR]