In this paper, a novel structure and a control method to improve the performance of inductive Heating circuits is proposed. In the presented structure, with the combination of the performance of a half-bridge resonant converter with voltage-boost capability, the reduction in output efficiency at low power and at high power is compensated to an acceptable level. The use of the low number of switches and diodes, the use of the high-quality capacitors with low capacities, good quality of the input current and also high power factor ensures the proper operation of the proposed converter. The switching of high frequency switches in the proposed structure is carried out as soft-switching where resulting in very low switching losses. In this converter, the design of the input filter in order to prevent the effects of electromagnetic interference has been prepared. Finally, to demonstrate the proposed structure operation, the simulation and experimental results are presented.

There is always a difference between the numerical, theoretical and experimental values of a physical quantity which is due to measurement errors. Electromagnetic hyperthermia using micro/nano particles is not an exceptional case. This deviation could affect the temperature distribution of domain. In this paper, the deviation of any effective parameter on temperature distribution, including concentration, injection area and radius of micro/nano particles, power and frequency of electromagnetic field are studied and uncertainty analysis is performed. The study was based on the Induction Heating by micro/nano particles in an electromagnetic field hyperthermia. The finite difference method was used to solve the equations numerically. Results show that the measurement of parameters such as electromagnetic field power, radius of micro/nano injection region should be done accurately.

In this article, we investigate the effect of frequency as one of the important factors in the three-dimensional process of Induction Heating through numerical modelling. Induction Heating is the process of Heating electrically conductive materials by electromagnetic Induction, which induces an eddy current within the material. Using the finite element method (FEM) and the comsol multiphysics software, we calculate the eddy current and the distribution of heat generated in both the workpiece and the inductor for different frequencies within the range of 0.75-5 kHz. To accomplish this, we utilize a real coil with a helix shape and a cylindrical workpiece. The results demonstrate that as the frequency increases, both the eddy current and the generated heat are transferred to the outer surface of the workpiece, becoming concentrated in a thin layer. In other words, these parameters exponentially decrease along the radius of the workpiece from the surface towards its interior.

Hyperthermia is one of the first applications of nanotechnology in medicine by using micro/nano magnetic particles that act based on the heat of ferric oxide nanoparticles or quantum dots in an external alternating magnetic field. In this study, a two-dimensional model of body and tumor tissues embedded is considered. Initially, the temperature distribution is obtained with respect to tumor properties and without the presence of an electromagnetic field. Then, the effect of the electromagnetic field on the temperature distribution is studied. The results are compared with those of other papers. The results indicate that the use of the electromagnetic field causes a significant rise in the tumor temperature; however, the risk of damage to the healthy tissues surrounding the cancerous tissue seems to be high. Then, the micro/nanoparticles are injected into the tumor tissue to focus energy on cancerous tissue and maximally transfer the heat onto the tissue. The temperature distribution in the state is compared with the case with no nanoparticles and other numerical works. The results demonstrate that with the injection of nanoparticles into the tumor, the maximum temperature location is transferred to the center of the tumor and also increases to 6° C. After determining the temperature distribution in the presence of nanoparticles, the effects of different variables of the problem are studied. According to the obtained results, the increase in the concentration and radius of nanoparticles have a positive effect on the temperature distribution in the tissue; on the other hand, the increase in the frequency and size of the electrodes have a negative effect. The relevant equations are solved numerically using the finite difference method.

Introduction: Heating of milk for the purpose of removing the bacterial pathogens should be done for the shortest time, and sufficient pasteurization must be ensured. The limitation of the classical methods of pasteurization is due to the high sensitivity of the milk to coagulation by the application of high temperature, which sometimes prevents the proper process and causes problems such as milk clotting and the formation of non-washable layers (milk stones) on the interior surface of the pasteurization tubes. These layers prevent the sufficient heat transfer and the adequacy of the pasteurization of the next inlet milk, and as a result, the mentioned milk contains high levels of microbial contamination that will be hazardous to consumers. Therefore, the aim is to find a suitable pasteurization method that does not have the above-mentioned disadvantages and also the milk obtained from the pasteurization process will have a higher quality. Therefore, in this research, the inductive electromagnetic flow heat was used for pasteurization of the milk. In this method, the milk container acts as the second coil of the electromagnetic current (transformer) and allows direct flow of electricity in the milk. In the preparatory steps of the project (stages 1 to 3), whose results are not mentioned in this article, milk pasteurized was done by Induction Heating in an attempt to modify, revise, and refine the usual classical process. In order to obtain the best conditions for milk pasteurization by the Induction method, the effect of four different factors were investigated, namely three diameters of the test vessel (23, 17 and 12 cm), three electrical conductivities (350, 1000 and 1600 watts), three temperatures (72, 75 And 84 ° C), three storage periods at pasteurization stage (15, 20 and 30 seconds) and three replications; Where 243 samples were selected in a completely randomized factorial experiment design. And the tested samples were categorized based on 1) the lowest percentage of residual microbial load, 2) the minimum time spent for pasteurization, and (3) the least Energy consumption for pasteurization. Material and methods: Three selected samples in the third stage of the previous project were prepared using the standard method in this study with the correct mixing at a certain temperature and used for the organoleptic test by the taste Group during the following steps. 1) Selection of 10 panelists. 2) Explaining the method and providing relevant questionnaires; 3) Checking and assuring the qualification of the panelists for evaluation (no smoking, medication, etc. ); 4) explaining the evaluation method to the testers. Then, the physical and organoleptic characteristics of the produced samples were determined by the panelist group using a grading method based on the color, aroma, taste, texture, consistency and concentration of the samples. Results and discussion: In the samples pasteurized using the Induction pasteurization method with 1600 W power transmission intensity, 30 seconds holding time, temperature of 84 ° C and 23 cm cross section of the container, desirable organoleptic and physical properties were obtained compared to the other samples and the control (pasteurized under conventional conditions). So, there was a significant difference between consistency, concentration, and aroma and customer satisfaction in two treatments at the level of 5% confidence and for the color attribute at 1% level due to the high speed of heat transfer in milk. Conclusion: The Induction method of pasteurization is superior to the HTST method in favor of the production of desirable organoleptic properties, and is a very good substitute for the classic method of the factory under the same conditions.

Induction Heating is widely used in metal industry for melting or Heating thin slabs in a continuous casting plant. The wide application is based on good efficiency, high production rate and non-polluting conditions. For designing a parallel resonant Induction Heating system, calculating the capacitance for the resonant circuit is important, because its value affects resonance frequency, output power, power quality factor, Heating efficiency and power factor.In this paper, phase controlled rectifier and H-bridge inverter are modeled. Then a method of finding an optimal value for the capacitance under voltage constraint is presented. This value is selected for maximizing output power of an Induction heater, while minimizing the power loss of capacitor at the same time. For this purpose, the role of equivalent series resistance in the choice of capacitance value is significantly recognized. In this regard, the Heating coil and the load of Induction Heating are modeled at first, and then the optimal value of capacitance is selected. Finally a complete model of heater and its power is simulated and effectiveness of the proposed method is verified.

Increasing the pasteurizing temperature of contaminated milk in classic method for completing the Heating process causes burning the milk layer on pasteurizer and creates thick milk stone. This event in addition to prevents the sufficient transfer of heat, produces carcinogenic compounds, changes milk color and increases remained microbial load in the milk, therefore threaten the product's safety. In the method used in this study (Induction Heating), electromagnetic current was induced into milk which could rise milk temperature faster than classic method. In this research, milk was pasteurized by using an Induction heater in 243 different conditions and optimized method was selected for adequate process via a factorial experiment design. In this experiment, the effects of four different factors including: 1) 3 intensities of electricity transmittance (350, 1000 and 1600 watts), 3 levels of test containers surface (12, 17 and 23 cm), 3 temperatures (72, 75 and 84oC) and 3 pasteurization time (15, 20 and 30 seconds) were used in three replications. The optimized method was selected in three steps based on 1) the minimum percentage of microbial load, 2) a minimum elapsed time for milk pasteurization and 3) the lowest energy consumption for processing, respectively. Consequently, the results showed that the destruction of total bacterial load was 99.5% in selected induced Heating method in comparison to classic method (98.23%). Moreover, coliform and Escherichia counts in induced Heating method have been one tenth to classic method. In induced Heating method, milk stone was not produced due to the fast Heating transfer.

This paper presents a design procedure and a new control method for power regulation of series resonant Induction Heating (IH) systems using a self-oscillating tuning loop. The proposed power regulator can accurately estimate the instantaneous phase angle and the main parameters of the resonant load. Moreover, the power control algorithm is devised based on a combination of Phase Shift (PS) and Pulse Density Modulation (PDM) methods. For simplicity, the tuning loop utilizes the PS control method for power regulation. Moreover, the Pulse Density Modulation (PDM) and frequency-sweep methods can be used in the proposed tuning loop. The new method is verified by a laboratory prototype with an output power of about 220 W and an operating frequency of about 60 kHz.

A B S T R A C T Temperature is one of the climate elements that has fluctuated a lot over time. When these fluctuations increase and decrease more than normal and are placed in the upper and lower regions of the statistical distribution, if continued, it can lead to the creation of Heating and cooling waves. The purpose of this study is to analyze the temporal and spatial changes in Heating and cooling waves in Iran during a period of 50 years. For this purpose, the temperature of 663 synoptic stations from 1962 to 2004 was obtained from the Esfazari database. Then, in order to complete this database, the daily temperature from 2004 to 2011 was obtained from the Meteorological Organization of the country and added to the aforementioned database. In order to perform calculations and draw maps, Matlab, grads and Surfer software have been used. The results of this study showed that the index of cooling waves and Heating waves, while having a direct effect on each other, had an increasing trend in most of the area of Iran. The statistical distribution of the index of cooling waves is more heterogeneous than that of the index of Heating waves. So that the spatial variation coefficient for cold waves is 84.22%. Also, the index of cooling waves has more spatial variability. The highest common diffraction of the index of Heating and cooling waves has been seen in the northwest, east and along the Zagros mountains. Analysis of the indexes trends show that heat waves have intensified in 65.8% of Iran and the intensity of cold waves has decreased in 48.5% of Iran Extended Abstract Introduction Temperature is one of the major climatic variables, which it has a direct impact on different aspects of human life. It plays an essential role in the growth of crops and is considered a key driver of the biological system(Reicosky et al, 1988). It is associated with several types of extremes, for example, heat and cold waves which caused human societies maximum damage. Past occurrences of heat waves hitherto had significant impacts on several aspects of society. Have increased Mortality and morbidity. Ecosystems can be affected, as well as increased pressure on infrastructures that support society, such as water, transportation, and energy(Dewce, 2016). The long-term change of extreme temperatures has a key role in climatic change. The form of statistical distribution and the variability of mean values and also extreme event indicate a change in the region. It can be a small relative change in the mean as a result of a large change in the probability of extreme occurrence. Also, the variation in temperature data variance is significantly more important than the mean, for assessing the extreme occurrence of climate(Toreti and Desiato, 2008). The average surface temperature has increased the world between 0.56 and 0.92 ° C over the past 100 years(IPCC, 2007). Meanwhile, it was in the Middle East, the average daily temperature increased by 0.4-0.5 ° C in decades(Kostopoulou et al, 2014; Tanarhte et al, 2012). Considering that not many studies have been done in the field of spatio-temporal Variations of the Heating and cooling waves thresholds in Iran, in this study, the spatio-temporal Variations of the Heating and cooling waves thresholds in Iran during 50 years were examined and analyzed.   Methodology The daily temperature from the beginning of the year 21/03/1967 to 19/05/2005 was obtained from the Esfazari database prepared by Dr. Masoudian at the University of Isfahan. In order to increase the time resolution of the mentioned database, the daily temperature of observations from 05/21/2005 to 05/12/2012 has been added to the mentioned database using the same method, and the exact spatial resolution (15 x 15 km) is used as a database. Threshold indices of Heating waves are the average numbers between the 95th and 99th percentiles, that is, the extreme hot threshold to the limit of excessively extreme hot. For extreme cool, from the 5th percentile down to zero is used. Of course, a condition was added to these thresholds, which is that these thresholds must be repeated two days in a row. These thresholds were extracted for each day in the 50 years of the study period and used as the original database. In order to analyze the relationship between cooling and Heating waves, Pearson's correlation coefficient was used and regression was used to analyze the trend.   Results and discussion The average of cold waves was 5.26 ° C and for the heat waves is 30.20° C. Generally, if the temperature is upper or lower than this threshold, it is considered as hot or cold temperatures. A comparison of the median, mode, and average of cold waves with heat waves shows that the distribution is more heterogeneous for cold waves and its CV is 84.22%. In southern Iran, the average threshold heat waves are higher. This situation can be caused by the effects of subtropical high-pressure radiation, low latitude, and proximity to the sea. Though the threshold is higher in these areas, fewer fluctuations and changes are seen in the area. Heights moderate the temperature so they pose a minimum threshold for heat waves i.e. an iso-threshold of 25 ° C is consistent along the Zagros mountain chains, but in the west and east of Zagros Mountains, the threshold of heat waves is increased. Heat waves have increased in most areas of the country. So nearly 85 percent of the Iran has been an increasing trend, of which 65.8 percent is statistically significant at the 95% confidence level. Still, more areas of the country (60 percent) have a trend between 0.00828 and 0.00161. As can be seen, only 15% of the land area (including the southwest and northwest of the Country) had decreased heat waves. Cold waves, in most parts of the country, have a Positive Trend. However, about 25 percent of the study area's cold waves have a negative trend. they are located in areas higher than Latitude 30°. The largest decline of the wave's trend along the country is highlands. Nowadays, most of the country, has a trend between 0.01494 and 0.00828 ° C, respectively. Conclusion Common changes and effects of heat and cold waves had a direct relationship in many parts of the country. It is remarkable common variance in the East reached 55 percent, according to statistical significance. In some areas of the northwest and southwest, which have been impressive heights, the common variance is 40 percent. This common variance in mountains area has been high values. Investigation of heat waves trend shows that 65.8% of Iran significant positive trend and 7.1% significant negative trend. Also, the cold waves trend has indicated a 48.5% significant positive trend and a 10.8% significant negative trend. Climate change and global warming have changed the frequency and severity of temperature extremes. The present study, by examining the number of warm waves, concluded that the warm waves have increased in magnitude in 65.8% of the Iran zone. Also, the study of the cold waves trend showed that 48.5 percent of Iran had a positive trend, which means that the amount of temperature in the cold waves increased In other words, the severity of the cold has been reduced And only 10.8 percent of Iran had a negative cold wave trend And it shows the intensity of these waves is reduced.   Funding There is no funding support.   Authors’ Contribution The authors contributed equally to the conceptualization and writing of the article. All of the authors approthe contenttent of the manuscript and agreed on all aspects of the work declaration of competing interest none.   Conflict of Interest The authors declared no conflict of interest.   Acknowledgments  We are grateful to all the scientific consultants of this paper.

One of the well-known methods regarding the return of asphalt mixture failures and, as a result, increasing its lifespan is self-healing, which has always been of interest to researchers due to its many benefits. Applying thermal energy or Heating the asphalt mixture leads to self-healing the asphalt mixture by accelerating the bitumen healing process. Two main methods of Induction Heating and microwave are used in this field. This article compares these two Heating-healing methods and introduces the more appropriate option. For this purpose, both Induction and microwave Heating methods have been used to apply heat to the components of the asphalt mixture, including bitumen, filler, and aggregates. The research results showed that the microwave Heating rate of bituminous mastic containing conductive materials is higher than its Induction Heating rate, so the microwave Heating rate of the mastic sample containing 10% by weight of iron powder (0.100 °C/s) was more than three times its Induction Heating rate (0.031 °C/s). Additionally, bituminous mastic heated with microwaves exhibits a more consistent thermal distribution, which enhances its self-healing properties. Unlike Induction Heating, which requires conductive additives and aggregates, the microwave method can heat components with or without conductive materials. However, addition of conductive materials can accelerate the microwave Heating process. For instance, adding 10% by weight of iron powder to bitumen could increase its microwave Heating rate from 0.083 to 0.100. In contrast, achieving the same results with the Induction Heating method requires several times more energy than the microwave method. Therefore, it is advisable to use the microwave Heating method instead of Induction Heating for thermal healing of asphalt mixtures.