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The heat pump is increasingly popular for the electric vehicles (EVs), however, there are no appropriate refrigerants. To provide long-term and environmental-friendly refrigerants in the heat pump for EVs, a test bench that can investigate the performance of an R410A prototype was built. The drop-in tests of three refrigerants (M1, M2, M3) developed previously with ultra-low GWP were carried out. The cooling and heating cycle performance were measured for R410A and alternative refrigerants. Experimental results showed the optimal refrigerant charge for the alternatives was less by 36-44% than that of the R410A system. For M1 and M2, the heating capacities showed 85-99% of those of the R410A system, with COP being 94-112%; the cooling capacities showed 94-109% of those of the R410A system, with COP being 99-107%. M3 showed much better COP than that of R410A system. The pressure drops were lower than those of R410A up to 21.6%, 25% and 55.7% for M1, M2 and M3, respectively. Furthermore, the alternative refrigerants showed better temperature match with air in the evaporator and condenser, the irreversible loss in the heat exchangers was also analyzed. This research will contribute to providing appropriate refrigerant substitutes in heat pump for EVs.

A new experimental method, i.e., isochoric cooling/heating cycle measurement using differential scanning calorimetry (DSC), is applied to investigate the hysteretic phenomenon of pure components an...

The knowledge of the dielectric properties of oils is of great importance for several industrial applications, such as microwave-assisted oil frying for foods and high voltage electric power transmission. In this paper, we present the complex permittivity of vegetable oils (canola, olive, soybean, coconut) at 2.50 GHz using the cavity perturbation technique from 28 to 200 °C (temperature close to the smoking point of oils). The measurements were taken with a cylindrical cavity operating at the TE(111) mode with an unloaded Q of 4950. In addition, free fatty acids, peroxide index and color were measured before and after heating.

Hydrocolloids are commonly used in canned pet food. However, their functional effects have not been quantified in this food format. The objective was to determine the effects of select hydrocolloids on batter consistency, heat penetration, and texture of canned pet food. Treatments were added to the formula as 1% dextrose (D) and 0.5% guar gum with 0.5% of either dextrose (DG), kappa carrageenan (KCG), locust bean gum (LBG), or xanthan gum (XGG). Data were analyzed as a 1-way ANOVA with batch as a random effect and separated by Fisher’s LSD at p &lt, 0.05. Batter consistency (distance traveled in 30 s) thickened with increasing levels of hydrocolloids (thinnest to thickest: 23.63 to 2.75 cm). The D treatment (12.08 min) accumulated greater lethality during the heating cycle compared to all others (average 9.09 min). The KCG treatment (27.00 N) was the firmest and D and DG (average 8.75 N) the softest with LBG and XGG (average 15.59 N) intermediate. Toughness was similar except D (67 N·mm) was less tough than DG (117 N·mm). The D treatment showed the greatest expressible moisture (49.91%), LBG and XGG the lowest (average 16.54%), and DG and KCG intermediate (average 25.26%). Hydrocolloids influenced heat penetration, likely due to differences in batter consistency, and affected finished product texture.

The appearance quality of plastic parts in weld lines can be improved significantly through the rapid heating cycle molding (RHCM) process. However, there is no evaluation method for measuring the appearance quality of weld lines to determine whether they are in a good or bad condition. In this study, RHCM parts were molded with electric heating and the total color difference dE of the Commission Internationale de l’Eclairage (CIE) Lab system was employed as the quantitative evaluation method for the appearance quality of weld line. The dE of weld lines under different heating temperature conditions was analyzed. The results indicate that the mold heating temperature significantly influences the appearance quality of weld lines and the CIE Lab system accurately assesses the appearance quality of weld lines. Moreover, the experimental results further demonstrate that the lightness difference ΔL has a significant influence on the dE of weld lines in plastic parts, whereas the color differences Δa and Δb have only a slight influence.

In this study, kamaboko gels were tyndallized at various temperatures and sterilization efficiency and impact on quality parameters were assessed.The microbiological, physical, and chemical properties of kamaboko gels were determined throughout the tyndallization process.Superior sterilization efficiency was achieved by tyndallization at a higher temperature; and the combination of heat-induced germination and thermal inactivation of spores was proposed as the main reason.The process had minimal effect on the color of gels. While tyndallized gels heated at 80 °C possessed superior physical properties, all gels showed impaired quality with the progress of heating cycles.Sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the cause of alterations in quality differed depending on the processing temperature.This study suggests that the sterility of products could be improved by increasing the processing temperature, time or number of heating cycle., 公開日: 2022-07-31

This paper deals with the study of the effects of thermal stress through partial discharge characteristics of 6/10kV XLPE insulated power cables. To study the effects of thermal stress through PD (Partial discharge) characteristics thermal aging is considered for healthy cable insulation. In this study, a cable under measurement is subjected to thermal aging or heating cycle. The measurement method followed is as per the specified method in the standard IEC: 60502-2 (2014). The experimental results are presented under the rated and at higher operating voltages of the cable. The analysis has been carried out and it is observed that due to the thermal aging effects on the cable insulation, the measured discharge quantity of PD is on the higher side. The results are presented for PD patterns of the specimen of cable sample considering the case of fresh sample and after the thermal stress. The PD patterns and the values obtained in both the cases shows dissimilarity, which can be utilized as samples for further PD pattern recognition.

The aim of this study was to simulate olive oil use and to monitor changes in the profile of fatty acids in home-made preparations using olive oil, which involve repeated heat treatment cycles. The material used in the experiment consisted of extra virgin and refined olive oil samples. Fatty acid profiles of olive oil samples were monitored after each heating cycle (10 min). The outcomes showed that cycles of heat treatment cause significant (p< 0.05) differences in the fatty acid profile of olive oil. A similar trend of differences (p< 0.05) was found between fatty acid profiles in extra virgin and refined olive oils. As expected, the main differences occurred in monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs). Cross-correlation analysis also showed differences between the fatty acid profiles. The most prolific changes were observed between the control samples and the heated (at 180°C) samples of refined olive oil in PUFAs, though a heating temperature of 220°C resulted in similar decrease in MUFAs and PUFAs, in both extra virgin and refined olive oil samples. The study showed differences in fatty acid profiles that can occur during the culinary heating of olive oil. Furthermore, the study indicated that culinary heating of extra virgin olive oil produced results similar to those of the refined olive oil heating at a lower temperature below 180°C.

We use molecular dynamic simulations to study the phase behavior of a coarse-grained lamella-forming A-b-B di-block copolymer under thin-film soft confinement for different heating cycle lengths, f...

This work investigates the effect of internal seeding and an initial cooling/heating cycle on the final crystal size distribution (CSD) during a combined cooling/antisolvent crystallization of l -asparagine monohydrate from it’s aqueous solution using isopropyl-alcohol as antisolvent. Internal seeds were generated by one-pot addition of various amounts of antisolvent to the crystallizer. It was then followed by a cooling/heating cycle to dissolve the fines produced and thus obtain a suitable initial seed. A combined cooling/antisolvent crystallization was then followed by employing a linear cooling profile with simultaneous addition of antisolvent with a constant mass flow rate to promote the growth of the internally generated seeds. The amount of initial antisolvent influences the characteristics of the internal seeds generated and the effect of initial amount of antisolvent on the final CSD is investigated. It was found that the introduction of a single cooling/heating cycle significantly improves the reproducibility of final CSD as well as the mean size. Overall, the study indicates that the application of internal seeding with a single cooling/heating cycle for fines dissolution is an effective technique to tailor crystal size distribution.

In situ age hardening phenomenon observed in as-sprayed Al-Sc binary alloys is reported. This, along with substantial grain refinement in the as-sprayed alloys exhibited hardness in the range of 605 MPa (Al-0.3 wt% Sc) to 923 MPa (Al-0.8 wt% Sc) that are comparable to the optimum hardness values typically obtained by age hardening in similar as-cast alloys. Transmission electron microscopy of the spray deposits revealed densely spaced Al3Sc precipitates of about 10 nm suggesting in-situ age hardening of these alloys during spray forming. This behavior is attributed to the inherent heating cycle associated with the spray forming process and the rapid kinetics of Al3Sc precipitation.

The automated complex is developed for precise heating of cylindrical titanium billets with various length and diameter. The high homogeneity temperature field of the billet is reached during the heating process. Achievement accuracy of the final temperature is $5\div 10\ {}^{\circ}\mathbf{C}$ . Billets of $400\div 750$ mm length and 165-275 mm diameter are exposed to heating. The heating cycle of billet in the inductor and the resistance furnace includes high-speed heating in induction heater and endurance of billet in the resistance furnace. Temperature control of a billet surface is made by means of a pyrometer located over a surface of billet in the middle of the inductor. Billet transportation from the induction heaters store and then into the resistance furnace is made by means of carts in automatic and manual modes.

The measurement of wood thermal expansion at fixed values of moisture content (MC) between the dry state and the cell wall saturation point is a very difficult task, as MC varies with temperature. Being hygroscopic deformations much larger than thermal ones, in order to evaluate the latter, when changing temperature also relative humidity should be adapted. To achieve this goal a special apparatus was designed to vary relative humidity as a function of temperature to keep MC constant, and thus to measure the thermal expansion coefficient without hygroscopic effects. The moisture content was assessed to remain constant by testing the heating cycle of each specimen, keeping the specimen itself on a precision balance before the thermal expansion measurement. The radial coefficients of thermal expansion of ten specimens of Norway spruce were measured at 7.0% and 11.4% MC. No statistically significant differences were found between the two data sets, indicating a negligible effect of moisture content on wood thermal expansion at MC values typical of indoor environments. However, the thermal expansion coefficients measured at 7.0% and 11.4% MC seem to be higher than the values for dry state reported in literature, indicating an effect of the moisture content.

Determining the optimal operating mode of equipment is an important task of modern energy. When planning the operating modes of thermal power plants (TPPs) in the short term (from several hours to several weeks), the following requirements are usually taken into account: production and distribution between the generating units of a given amount of electricity, supply of a given capacity in accordance with the schedule for each group of generation supply points, heat supply to external consumers in accordance with the planned schedule of heat supply. Accounting for heat supply to external consumers allows us to consider in more detail the influence of the volume of heat withdrawals on the area of permissible loads of generating units. This article pays special attention to the optimization of equipment operating modes taking into account the volumes of heat withdrawals from generating units.

Botez, Martinez, Price, Martinez and Leal claim in J. Phys. Chem. Solids 129 (2019) 324–328 that superprotonic CsH2PO4 (CDP) is stable in dry air at 260 °C. We discuss their observations and conclude that CDP is not stable unless sufficiently confined under a high humidity and high-pressure atmosphere, eventually formed from the sample itself. Temperature- and time-resolved impedance spectroscopy data show that a superprotonic CDP pellet measured in a hermetically sealed chamber holds a stable superprotonic conductivity of ~2×10−2 S cm−1 over a time span of 50 h at a temperature of 260 °C if the amount of sample is large enough and the container small and tight. Nyquist plots have confirmed the superprotonic nature of the conduction. X-ray diffraction data have revealed that CDP is present after the heating cycle to obtain superprotonic conductivity, but possibly CDP partly was decomposed to Cs2H2P2O7 during the heating and was reformed reacting with water during the cooling.

Background: Bhasmas are unique Ayurvedic organometallic preparations used for medicinal purpose. Quality of bhasma depends upon quality of starting materials, processing ingredients, meticulous trituration and heating cycle. In Ayurveda, Vanga bhasma is traditional Indian medicine which is an organometallic preparation treated with plant extract. It is especially used in the treatments of diseases related to gastrointestinal tract and genitor urinary system. However detailed characterization studies after synthesis are important which shows authenticity of product. Objective: The present study deals with the preparation of Vanga bhasma according to the procedure mentioned in the Ayurvedic literature. Synthesized bhasma was characterized by various analytical techniques and also compared with commercial sample. Material and method: Different steps involved in synthesis of Vanga bhasma include shodhan (purification/detoxification), jaran (heating and stirring), bhavan (levigation) and maran (incineration). Bhasma was incinerated (maran process) by traditional method of heating as well as using muffle furnace. These two products obtained from Maran (incineration) and commercial sample were analyzed for quality control checks, on the parameters described in Ayurvedic texts as well as modern techniques such as TEM, SEM, EDX, XRD, DLS and FTIR were done to find out the nature and form of the drug prepared. The in vitro gastric and gastrointestinal (pancreatic) bioaccessibility of Bhasma were also determined. Results: The study reveals that the synthesized Bhasma was converted into its nontoxic oxide form and had a highly reduced particle size observed from SEM images. These studies reveal that Vanga Bhasma prepared by traditional method of heating (Sn1) has 50% nanoparticles (150–300 nm range) that prepared by using electric muffle furnace (Sn2) has 100% nanoparticles (50–100 nm range) while commercial samples (Sn3) has 50% nanoparticles (100–300 nm range). Conclusion: The study confirmed the formation of organometallic compound (SnO2) at the end of the manufacturing process. The percentage bioaccessibility for gastrointestinal digestion is more than the gastric digestion. Hence, it is concluded that Vanga Bhasma can be useful nanomedicine. Keywords: Vanga Bhasma, Jaran, Levigation, Purification, Characterization, Bio-accessibility

Background: There are a lot of techniques to obturate the root canals, but lateral condensation of gutta-percha is the most used one. An important aspect of thermafil is the error margin tolerated by the manufacturer in the production of plastic carriers. In literature, there is no evidence about discrepancy percentage between different carriers. It is demonstrated that the error margin of gutta-percha is 0.5% and is 0.2% for metal files (ISO standards). Objective: The aim of this study was to evaluate the real dimensions of thermafil plastic carriers observed by the stereo microscope measuring the dimensional discrepancy between them. Methods: For this study, 80 new thermafil (Dentsply Maillefer) have been selected. 40 thermafil 0.25 and 40 thermafil 0.30. Through 60X stereo microscope, the dimensions of the plastic carrier tips have been measured. The dimensions of the plastic carrier were also measured after a heating cycle. ZL GAL 11TUSM (Zetaline stereo evolution) microscope was used to observe the samples. Measurements were made through a dedicated software (Image Focus). All samples were analysed at 60X. Results: A non-parametric paired test (Wilcoxon test) was used to compare baseline and after heating values; p-values ≤ 0.05 were assumed to be statistically significant. Conclusion: The samples we measured showed a mean value of the diameters in Thermafil 25 that was 0.27 mm, for Thermafil 30 the mean value was 0.33 mm. We have measured a dimensional variable of 8% in the 25 group while in group 30 the maximum possible variation found was 4%, that’s why we propose a new protocol of obturation with thermafil. We can also conclude that a single heating process does not affect clinically the plastic carrier dimensions.

The paper presents selected technical and economic aspects related to the use of air heat pumps for the preparation of domestic hot water DHW. The research shows that heating the water in the 130 dm3 storage tank with the A21/W30-50 profile lasted an average of 130 minutes, and the heat pump consumed about 2.2 kWh of energy per one heating cycle. Heating water in a 130 dm3 storage tank from 25°C to 40°C lasted an average of 60 minutes, while heating water for another 5°C took 30 minutes. The operation of the heat pump in the higher temperature of the water in the storage tank is less effective, making the heating of water in the tank above 50°C is ineffective.

Current defrosting methods for air source heat pumps always implement defrosting in the frost layer growth period. As a result, the heating performance decays because of the frost layer growth, and large amounts of energy and time are consumed to melt the frost layer. Moreover, the heating cycle is interrupted when defrosting cycle starts, which leads to discontinuous heating. Frost layer forms and grows on the surfaces of embryos which form in the initial stage of frosting process. If the embryos are removed timely, the frosting process can be cut off. Thus, a comprehensive defrosting method, which combines surface characteristic of superhydrophobic fin and high-speed hot airflow, is proposed in this paper. Its mechanism and realization process are analyzed, and preliminary experiments are performed to verify its feasibility. When the high-speed hot airflow acts on the fin surface, most of the embryos are instantaneously blown away by the airflow due to the weak adhesion of the superhydrophobic surface. Only a few small embryos remain on the surface, which are evaporated quickly in 3.5 s. Preliminary results indicate that the novel defrosting method is feasible which can avoid the disadvantages of current defrosting methods.

The mountain pine beetle emergence is temperature dependent. We hypothesize that heating cycles defined and determined by summer (July and August) daily temperature series represent reliable windows for potential beetle emergence. In this study, we first downscaled two coarse resolution meteorological datasets (the North American Regional Reanalysis data and provincial gridded climate data) using an elevation correction approach. We mapped heating cycles spatially and temporally across the province using the maximum daily temperatures derived from the downscaled meteorological data. The mean absolute errors (MAEs) and mean bias errors (MBEs) in the downscaled maximum daily temperature based on 30 weather stations reveal that the elevation-based downscaling approach is effective and the average errors do not significantly affect the spatial and temporal patterns of heating cycles in terms of the four key variables and frequency distributions of heating cycles. The temporal patterns of heating cycles for most of the monitoring years sufficiently capture the major emergence peaks observed at 16 monitoring sites. Therefore, the hypothesis above is valid and potential beetle emergence can be spatially and temporally mapped using heating cycles at the landscape scale.

Registration of thermoluminescence (TL) spectra technique for irradiated samples in Perkin Elmer LS 55 spectrometer using developed high-temperature accessory during single heating cycle is shown. Functionality of serial instrument for RT–773 K temperature range is significantly widen. Spectrally resolved TL dependencies for h-BN micropowders and bulk AlN single crystals following UV irradiation are studied. TL spectral features of h-BN powders, synthesized by carbamide and plasma-chemical techniques, are determined and quantified. It is shown that the difference between TL curves obtained by the described and the standard modes does not exceed 10%.

In rotational moulding, due to bi-axial nature of mould rotation, there is a dearth of accurate and cost-effective thermal data measurement techniques and equipment. This necessitates reliable prediction of thickness for different temperatures and critical timings of the process like switching off the oven. Therefore, an attempt has been made to estimate the appropriate heating cycle time and thickness variation using process simulation. The thickness of polymer layer during intermediate temperatures and cycle time can be perceived from the simulation. It is also predicted that, a rotomoulded product of thickness 5mm requires an overall heating cycle time of 24.5minutes.

The experimental results on stability of the relative elongation of isostatic isotropic GIP-4 graphite under cyclic thermal loads within the temperature range of 1240–2270 K are presented.

Asphalt pavement is form an integral part of any transportation system. Temperature is the significant factor that effect on the performance and life span of a pavement. This paper study the relationship between the air temperature and asphalt pavement temperature and using Excel in order to predicate surface asphalt pavement model for Muscat climate. The models were compared with the standard models SHRP and LTPP models [3]. The development models resulted the surface pavement temperature was taken more time in heating cycle than air temperature. When compared the air temperature and surface asphalt pavement temperature with the standards models SHRP and LTPP models. There was difference between them due to the standards models was design for low temperature under zero where in Muscat temperature cannot be under zero [2].

Objective To analyse the linear coefficient of thermal expansion (LCTE) of different tooth regions using thermal mechanical analysis (TMA). Methods Specimens (n = 12) were sectioned from different anatomical areas from recently extracted molars using a slow-speed diamond saw. During analysis the specimens were kept saturated with phosphate-buffered saline using a specially designed quartz container that was placed inside the TMA unit. Specimens were subjected to a 15–50 °C heating cycle as well as a 50–15 °C cooling cycle at a 5 °C/min rate. LCTE was determined using the slope of each respective cycle with each specimen being run three times with the mean representing the LCTE of each specimen. Mean results between heating and cooling for each sample were compared with paired t-test while results between regions were compared with ANOVA and Tukey post hoc (p = 0.05). Results Significant differences in LCTE were noted between tooth regions with caries-affected dentine, cervical, and root surfaces exhibited significantly lower LCTE. Furthermore, cooling LCTE was significantly greater than heating in all areas. Conclusions Under the conditions of this study, molar LCTE was found not to be uniform in all areas. Furthermore, cooling LCTE was found to be greater than heating.

This paper presents an experimental investigation on flexural strength of concrete subjected to thermal cyclic loads. The tests were carried out on normal weight concrete specimens of size 100 mm × 100 mm × 500 mm. The concrete was subjected to a constant temperature of 200°C for 7, 14, 21 and 28 heating cycles. One heating cycle corresponds to eight hours heating and subsequent cooling in twenty four hours. After the desired number of thermal cycles, the specimens were tested for flexural strength of concrete. Test results were critically examined and the effects of various parameters in the present work have been discussed.

This paper describes a method of measuring the glass transition temperature, by dynamic mechanical analysis, in which the glass transition temperature can be obtained by determining the temperature at which the peak value of damping is observed. The novelty of the method reported here is to use a fast heating technique with a feedback circuit that maintains the specimen at resonance. By doing the test in about a minute, polymer cure is not altered significantly by the heating cycle.

Precipitation during the industrial cool down takes place predominantly above 300 degrees C in the EN AW-6082 and 6005 alloys. The phase precipitation throughout cooling is equilibrium beta phase. A considerable capacity is retained after the cool down for further precipitation during a subsequent heating cycle. The beta-Mg2Si is once again the predominant phase that forms during a scan heating cycle employed in exactly the same manner with the industrial billet preheating operation. The precipitation in the 6060 alloy, on the other hand, occurs predominantly below 300 degrees C with additionally beta'-Mg2Si particles formed below 200 degrees C.