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This paper presents a refined full‐domain model for the fluidic‐thermal coupled analyses of a 15‐kW 30,000‐rpm high‐speed permanent magnet synchronous machine (HS‐PMSM) considering the heat generation and dissipation of the bearing components. In order to analyse the heat dissipation capacities of the bearing components, firstly, the fluid flow conditions inside the bearings with different revolution and rotation ratios are researched, and the most serious case is taken in the full‐domain calculations. Secondly, the three‐dimensional (3D) full‐domain model is established, and the fluidic‐thermal analyses are conducted based on the basic principles of numerical heat transfer and CFD. During calculations, in order to obtain the temperature rise precisely, the angular contact ball bearings are well modelled with all the internal components including the oil films, and the frictional loss in the bearings are computed by the Palmgren model. A 15‐kW 30,000‐rpm HS‐PMSM prototype is established and tested to verify the full domain thermal modelling methodologies and indirectly validate the bearing performance calculations. Finally, a self‐ventilated structure is employed to prevent the bearing temperature rise, and the cooling effectiveness is validated by numerical calculations.

The axial permanent magnet magnetic bearingless flywheel machine (APM-BFM) mostly operates under the state of high-power fast charging and discharging. Due to the characteristics of high-power density per unit volume, the centralized windings have small heat dissipation area and high thermal loads, the temperature rise on APM-BFM is a very important issue. Thermal analysis is thus of particular importance particularly for modern machines since the temperature rise and distribution are significant during their running under higher electromagnetic loads commonly used nowadays. In this paper, the equivalent thermal network method is proposed to evaluate the temperature rise of the APM-BFM. The equivalent thermal network model is established based on the basic theorem of heat transfer. The thermal resistance and heat source in the machine are analyzed and calculated, and the thermal balance equation is established. The temperature rise of each node is solved, and finally the validity of the model is verified by finite element magnetic-thermal coupling simulation.

Loss and temperature increase due to DC bias occurring in power transformers may lead to damage and reduced lifespan. To study the influence of different levels of DC bias on the temperature rise in transformer structural components, 0, 8, and 16 A DC were introduced into the MV side of a test transformer. A 2D axisymmetric finite element model was also established to calculate and analyze the distribution of winding loss under DC bias. Combined with the 3D field-circuit coupling model, the core loss under DC bias was calculated on the basis of the half-wave average algorithm. The eddy loss of the steel structure was also obtained using a 3D field-circuit coupling model. On the basis of the thermal-fluid coupling model, the transient temperature changes of typical points were simulated. Results showed that the calculation error of loss and temperature are small when the DC current is 0 A. Moreover, the error of loss and temperature increases when the DC current is 8 or 16 A. The methods used in this study lay the foundation for subsequent research on the temperature rise of large-capacity power transformers under DC bias, especially for the single phase transformers with ONAN cooling mode.

Based on the theory of porous electrodes and the properties of lithium iron batteries, an electrochemical‐thermal coupling model of a single cell was established. The model was mainly used to study the temperature rise and temperature distribution characteristics in different regions of lithium iron batteries under different working conditions. In addition, a heat dissipation comparison analysis was carried out for different types of liquid cold runners, the optimal runner scheme was selected, and a structural optimization analysis was carried out. The simulation results show that the lithium iron battery discharges under the same ambient temperature and different C rates, and the battery temperature continuously increases with C. The temperature rise is mainly affected by Joule heat, and when the lithium iron battery is discharged at the same C but different ambient temperatures, the temperature rise of the lithium iron battery shows a decreasing trend with the increase in ambient temperature in a certain temperature range. The serial flow channel solution induces the best thermal behavior. Using the response surface optimization analysis, the three independent variable factors at which the temperature equilibrium R reaches the largest value under the liquid cooling module model are the rectangular flow channel length‐to‐width ratio, flow rate, and thermal conductivity.

This work presents a physics-based predictive model for temperature rise in cylindrical solids heated by constant-strength, periodic-motion heat source. The heat source motion path, heat transfer boundary conditions and solid dimension are considered in the theoretical model. Analytical solutions to both the infinite or finite length cylinders are constructed with respect to convection and corresponding boundary conditions. Dimensionless controlling parameters are discussed to reveal temperature field evolution. The predicted results in the temperature rise agreed well with the measured data for a Z-direction feeding drive screw shaft system. The proposed model provides an efficient and accurate design tool for engineering calculation and process-parameter planning through inverse analysis.

For highly viscous polymer melts, considerable fluid temperature rises produced by viscous heating can be a disturbing factor in viscosity measurements. By scrutinizing the experimental and simulated capillary pressure losses for polymeric liquids, we demonstrate the importance of applying a viscous heating correction to the shear viscosity, so as to correct for large errors introduced by the undesirable temperature rises. Specifically, on the basis of a theoretical derivation and 3-D nonisothermal flow simulation, an approach is developed for retrieving the equivalent shear viscosity in capillary rheometry, and we show that the shear viscosity can be evaluated by using the average fluid temperature at the wall, instead of the bulk temperature, as previously assumed. With the help of a viscous Cross model in analyzing the shear-dominated capillary flow, it is possible to extract the viscous heating contribution to capillary pressure loss, and the general validity of the methodology is assessed using the experiments on a series of thermoplastic melts, including polymers of amorphous, crystalline, and filler-reinforced types. The predictions of the viscous model based on the equivalent viscosity are found to be in good to excellent agreement with experimental pressure drops. For all the materials studied, a near material-independent scaling relation between the dimensionless temperature rise (Θ) and the Nahme number (Na) is found, Θ ~ Na0.72, from which the fluid temperature rise due to viscous heating as well as the resultant viscosity change can be predicted.

The ambient temperature has a great influence on the discharge and charging performance of a lithium battery, which may cause thermal runaway of the battery pack in extreme cases. In terms of the poor cooling effect caused by only using the cooling bottom plate for liquid cooling and the fact that the battery pack needs to be preheated before it can be used normally, a new cooling structure design was carried out, and a variety of cooling schemes and preheating schemes were proposed for analysis and comparison. The Star ccm+ simulation software was used to analyze and study their liquid cooling performance and preheating performance under different conditions. The best cooling scheme and preheating scheme were obtained by comparing the results of the simulation analysis. The simulation results show that the cooling performance of the cooling scheme using two vertical cooling plates and one cooling bottom plate is the best, and the preheating performance is best when the preheating liquid is used with a certain temperature flow through the preheating pipe of the battery pack for a period of time, and then the battery pack is discharged until the battery pack temperature reaches the working temperature range. The research results have reference value for the control of the ambient temperature of a vehicle lithium iron phosphate battery.

The continuous operation of the wireless power transfer system (WPTS) under high-frequency switching activity might cause a temperature rise in various system's components. That temperature rise might increase the resistance of the primary and secondary coils, which will lead to a significant decline in the system's efficiency. To address this problem at the design stage, we investigate the optimal range of the coupling coefficient that suppresses the efficiency drop due to the increasing resistance of the WPTS components. The proposed optimal range of the coupling coefficient can also ensure the output power requirements of the WPTS. Using four different WPTSs, the determination method for the optimal range of coupling coefficients under different system operational frequencies was developed and implemented. A 3-kW resonant experimental prototype WPTS was designed and built to validate the proposed coupling coefficients experimentally. The experimental results show that the optimized coupling range successfully suppressed the efficiency decline resulting from the increasing resistance caused by temperature rise.

Electromagnetic forming is a well-developed high-rate forming technology. An important issue of this technology is the temperature rise of the driving coil, which can adversely affect the coil service life. This paper is aimed at addressing this issue through detailed investigation of an electromagnetic forming based on half-wave current method. On the basis of the principle of electromagnetic forming and finite element modelling, this paper compares and analyzes the temperature rise profile of the driving coil along with the forming efficiency of the workpiece in the traditional discharge, the crowbar discharge and the half-wave current discharge models. Results show that with the same system discharge parameters, the half-wave current method can reduce the Joule heating of the driving coil from 1.82kJ to 1.3kJ, which effectively reduces the temperature rise of the driving coil. At the same time, the workpiece forming efficiency is improved from 9.6% to 11.8%. Thus, the half-wave current method can solve the issue of the temperature rise of the driving coil to some extent and promote the process of industrial applications of the electromagnetic forming technology.

The objective of this article is to study the performance characteristics of the journal bearing experimentally having different geometries operating with commercial Mobil grade lubricants that are used in power plant. Three grades of Mobil lubricants (DTE 24, DTE 25, and DTE 26) have been considered during the study. TiO2 nanoparticle additives have also been considered during the study as a lubricant additive to examine the performance of journal bearings. An analytical approach was presented in the author’s earlier work to obtain pressure and temperature profile. The dynamic characteristics such as stiffness and damping properties of journal bearings are represented in this paper. An experimental test rig is developed to accommodate any geometrical type of bearing. An elliptical journal bearing shows the superior performance than that of a plain bearing. The obtained experimental results are in a very good agreement with theoretical results for pressure and temperature profile.

This paper aims at studying the effect of cable characteristics on the thermal instability of 320 kV and 500 kV Cross-Linked Polyethylene XLPE-insulated high voltage direct-current (HVDC) cables buried in soil for different values of the applied voltages, by the means of sensitivity analysis of the insulation losses to the electrical conductivity coefficients of temperature and electric field, a and b. It also finds the value of dielectric loss coefficient βd for DC cables, which allows an analytical calculation of the temperature rise as a function of insulation losses and thermal resistances. A Matlab code is used to iteratively solve Maxwell’s equations and find the electric field distribution, the insulation losses and the temperature rise inside the insulation due to insulation losses of the cable subjected to load cycles according to CIGRÉ Technical Brochure 496. Thermal stability diagrams are found to study the thermal instability and its relationship with the cable ampacity. The results show high dependency of the thermal stability on the electrical conductivity of cable insulating material, as expressed via the conductivity coefficients of temperature and electric field. The effect of insulation thickness on both the insulation losses and the thermal stability is also investigated.

Enhanced mechanical properties in terms of strain hardening capacity and uniform strain have been measured for recently developed TRIP-TWIP β − metastable Ti alloys. However, hardly anything has been reported about their fracture properties. An original fracture scenario including adiabatic shear banding is proposed for both flat and cylindrical tensile specimens of Ti-12wt.% Mo tested in quasi-static conditions at room temperature. The geometry of the tensile specimens has a strong influence on the fracture mechanism. The fusible coating method was used with Sn and Cu coatings to qualitatively evaluate the evolution of the temperature during fracture, colder than 232°C during crack initiation and increasing up to the melting temperature of the alloy during crack propagation. High-speed imaging was also used to estimate the evolution of the crack propagation speed, increasing up to 1,840 m . s − 1 , a level corresponding to unstable crack propagation. The evolution of the temperature rise and of the crack speed is linked to the specific fracture patterns.

The highly complex contact interface phenomena require analysis at different length scales ranging from nanometer up to nearly centimeter scales. When two nominally smooth surfaces are brought into contact, solid-solid interaction across their contact interface is confined at multiple protrusions (asperities) of various shapes, sizes, and heights. The deformation mechanisms encountered at the asperity level control the surface conformity, which, in turn, influences the transmission of traction, heat, and electric current across the contact interface. Thus, the multiscale roughness of real surfaces necessitates the advance of methodologies and contact models that bridge the spectrum of relevant length scales. Rough surfaces have been traditionally charac¬terized by statistical parameters, which cannot be uniquely deter-mined because they depend on the sampling interval and the resolution of the mea¬sur¬ing device. On the contrary, the scale-invariant parameters employed in fractal geometry provide an unbiased representa¬tion of the surface topography. This article provides an appraisal of the multiscale mechanical, thermal, and electrical characteristics of rough contact interfaces demonstrating fractal behavior. Theoretical treatments of elastic, elastic-plastic, and fully plastic deformation, heat conduction, temperature rise, and electrical contact resistance are presented for contact interfaces characterized by fractal geometry, providing a fundamental basis for developing multiscale thermo-electro-mechanics analytical treatments for contacting solid bodies.

Multi-break vacuum circuit breakers (VCBs) are the most potential approach for applying VCBs to high voltage power system. However, it has higher thermal stability requirements than normal single break VCBs due to its complex structure and high rated current. In this paper, a novel 363 kV/5000 A/63 kA SF6 gas insulate (GI) VCB with series and parallel structure is proposed. To analyze its temperature rise, a 3D coupled electromagnetic-thermal-fluid model is established based on actual size and calculated by finite element method under rated condition, which enables prediction of the temperature distribution of the contacts of VCB and bus bar. In the numerical model, the vacuum chamber is modelled as solid material with temperature dependent effective thermal conductivity while skin effect, nonlinear property of conductor resistivity and turbulence model are taken into consideration. The simulation results show that the hot spot is the contacts of VCB with a temperature of 102.2 K, while the temperature of busbars reach at 92.3 K. In addition, the influences of contact resistance, short circuit current on the temperature rise are discussed. Finally, the simulation results are validated by temperature rise experiment on prototype. Using the proposed model, the temperature rise and hot spot area can be predicted in advance, which could finally facilitate the design and performance evaluation of the 363 kV GI-VCB.

Over-temperature is a fatal problem when a motor is running. In this work, the temperature and temperature rise of the motor are investigated experimentally and numerically. The experiment is conducted by means of both voltmeter-ammeter method and embedding thermal resistors, to obtain the mean temperature and the local temperature of the stator coils, respectively. The numerical calculation is carried out to study the temperature field of the stator and the rotor, which agrees well with the experimental result. What?s more, the sensitivity analysis of eighteen factors to the temperature is investigated using combined CFD-Taguchi method. The main conclusions are drawn. Firstly, according to the numerical results, the maximal temperature and the maximal temperature rise at rated speed are 143? and 99 K, respectively. The values are 145.8? and 90 K, according to the experimental results, which are lower than the temperature allowed, 180? and temperature rise allowed, 125 K. Secondly, the sensitivity analysis results suggest that the key factors influencing the temperature are in sequence the ambient temperature, the copper loss, the thickness of the layers, the outside convection heat transfer coefficient of crate, the iron loss at the tooth and thermal conductivity of the insulation. The contact thermal resistance and the thermal conductivity of the core in axial direction have little influence on the temperature. The rank to the temperature rise is similar except the ambient temperature, which has little effect on the temperature rise.

Transient characteristics in the starting process play an important role in the design and operation of high-power-density and high-voltage induction motor. A field-circuit coupling model is proposed to analyze the transient fluid flow and temperature rise of a YJKK 500-4 2500 kW HPDHV induction motor in the starting process. The wind resistance network model is built to investigate the transient fluid flow and is used to obtain the heat dissipation boundary condition of the transient temperature calculation. The transient electric current is the key to the heat source of the temperature distribution and is calculated by the dynamic mathematical model. According to the obtained heat dissipation boundary condition and heat source, the 3-D fluid-solid coupling model is solved to obtain the transient temperature distribution. Moreover, the highest temperature rise in the starting process is greatly affected by the load. The simulation results show that the smaller fluid flow and the starting current make the winding temperature rise rapidly before the rotating speed of the motor reaches the rated value. When the load is much heavier, the starting time becomes longer and the winding temperature in the starting process will rise rapidly. The experimental results indicate that the proposed model is validated.

This paper elucidates the damage characteristics, microstructure response and temperature rise of steel alloy Q235B suffered from lightning currents, which is the basis for lightning protection of oil tanks. Damage is inflicted in the designed Q235B specimens by using the multi-waveform multi-pulse impulse current generator to characterize the damage response induced by four typical lightning current components. The changes in the element composition and micro-hardness of Q235B are documented in the experiment. The microstructure changes in response to the temperature rise are analyzed by the proposed lightning-metal temperature rise model. The results reveal that, first, return stroke current with an amplitude of 201.2 kA leads to the largest damaged area of 3523.8 mm2. Continuing current in the stroke intervals with a charge transfer of 12.1 C results in the damaged area of 12.6 mm2 and the damaged depth of 0.5 mm. Long continuing current after stroke with a charge transfer of 210.1 C leads to the deepest damaged depth of 3.0 mm. The demixing phenomenon occurs on the cross-section, forming the damage zone, transition zone, and origin zone. The damage zone mainly consists of martensite transferred from pearlite and ferrite at temperature 990 °C. The transition zone is mainly martensite and ferrite forming at temperature 900 °C. The hardness of the three zones is 450, 310, and 180, respectively. The damaged depth is only 0.001 mm caused by the subsequent return stroke current with an amplitude of 102.2 kA.

This study investigates the thermal response of titanium alloy fretting sliding through a numerical approach with the consideration of the friction dissipation, plastic dissipation, surface roughness and wear. The fretting sliding of a cylindrical pad on a specimen with surface roughness is modeled to predict the temperature distribution, the evolution of the wear profile, and the fields of surface and subsurface stresses. Specifically, a thermo-elasto-plastic constitutive model considering the thermal-induced softening of material properties is developed to evaluate the contact pressure and the tangential stress on the surfaces as well as the subsurface stresses in the contacting components. The friction and plastic energy dissipations function together as the heat source to cause the temperature rise in the contact zone. A modified Archard model is used to predict the wear profile of the contact surface and change the contact geometry. The models are then incorporated in the finite element analysis of the fretting sliding to evaluate the thermal response. The influences of the plastic dissipation and the surface roughness on the temperature rise in the fretting sliding are discussed.

Cutting temperature, machining parameters, workpiece material, and cutting tool geometry have a significant influence on the achievement of the desired quality of product at a satisfactory cost. The aim of the present study was to develop an empirical model for predicting temperature rise (Tr) and surface roughness (Ra) in terms of spindle speed (N), feed rate (F), axial depth of cut (Da), radial depth of cut (Dr), and radial rake angle (γ). The experiment was conducted on Al 6061-T6 by using a high-speed steel (HSS) end cutter based on the central composite design of response surface methodology (RSM). A second order mathematical model in terms of machining parameters was developed. The Analysis of Variance (ANOVA) was used to study the performance characteristics in the machining process. The values of Prob>F less than 0.05 indicate that the model terms are significant. The experimental results indicate that the formation of surface defect in the end milling of Al 6061-T6 results from the re-deposited tool material, plucking, feed marks, micro-pits, and chip layer formation. The high quality of the surface texture is obtained in the combined conditions of high spindle speed, optimal feed rate, lower axial and radial depths of cut, and radial rake angle. Multi objective genetic algorithm (MOGA) has been applied to optimize the machining parameters that simultaneously minimize temperature rise and surface roughness. A set of Pareto-optimal solutions provides flexibility to the manufacturer and the process engineer to select the best setting based on the quality requirements and applications. A verification and validation process shows that the predicted values were found to be in good agreement with the observed values.

Purpose: To investigate the temperature changes in the primary teeth pulp chambers during the curing of different colored compomers Materials and Methods: Class II cavities were prepared in primary mandibular second molars (n=5). Gold, blue, green, berry, and tooth (control group) colored compomers were tested in two steps (aproximal and occlusal). Measurement of pulp chamber temperature changes during curing was performed with a J type thermocouple. The data including differences between the highest and initial temperature values were recorded and analyzed by two-way ANOVA and Mann-Whitney U tests Results: There were statistically significant differences temperature changes in groups (p < 0.05). Cümle yeniden kurulabilir. Gold colored compomer Demonstrate the highest temperature increase in both proximal and occlusal surfaces. Tooth colored compomer (A2) Demonstrate the lower temperature increase. The temperature increase in aproximal cavities was found higher than the temperature increase in occlusal cavities. Conclusions: Colored compomer can be an alternative restorative materials in superficial class I and II cavities in primary teeth. Dark coloured compomers should be used in deep cavities. Running Title: Temperature Changes During Curing of Colored Compomers. © 2018 Cumhuriyet University Faculty of Dentistry., Amaç: Farklı renkli kompomerlerin ışıkla sertleşimesi sırasında süt dişi pulpa odasındaki sıcaklık değişikliklerin araştırılması amaçlanmaktadır. Materyal ve Metod: İkinci molar süt dişleri Sınıf II kaviteler hazırlandı (n=5). Altın sarısı, mavi, yeşil, mor ve diş rengindeki kompomerler iki aşamada (aproksimal ve oklüzal) test edildi. Işıkla sertleşme sırasında meydana gelen pulpa odasındaki sıcaklık değişimi ölçümleri J tipi termokupl ile gerçekleştirilmiştir. En yüksek sıcaklık ve başlangıç sıcaklıkları arasındaki farklar veri olarak kaydedildi ve analizleri iki yönlü-ANOVA ve MannWhitney U testi ile yapıldı. Results: Sıcaklık değişimleri arasında istatiksel olarak anlamlı farklar vardı (p

Adiabatic shear banding propagating at very large speed was observed during the unstable fracture of TRIP-TWIP β -metastable Ti-12 wt.% Mo alloy under quasi-static loading. The fusible coating method was used with five different coatings to assess the predicted temperature variations. Two one-dimensional models are compared based on parameters measured on fractured samples of Ti-12 wt.% Mo alloy. The importance of the thickness of the shear band as well as of the shearing time are highlighted. A new two-dimensional model is then developed to represent the nucleation and propagation of the shear band. Finally, an analytical one-dimensional model is proposed to estimate the temperature rise occurring during adiabatic shear banding of other metallic alloys from easily accessible physical and mechanical properties.

The main objective of this paper is to propose an algorithm to predict and compare the sizes of the bus bar with materials like copper and aluminum by considering the allowable ampacity and allowable temperature rise with natural and forced convection cooling arrangement. Theoretical analysis is carried out with modified size of the copper bus bar using MATLAB, to analyze the ampacity and temperature variation under the natural and forced convection mode. The algebraic equation developed from thermal model is solved using MATLAB for the determination of the allowable temperature rise and ampacity of rectangular-section bus bars of copper and aluminum and also for different sizes of bus bar. An algorithm has been developed for the analysis. Experimental observations of temperature variation in copper bus bar with standard size under natural and forced cooling mode are validated with the algebraic equation developed from thermal model is solved using MATLAB. It is concluded that bus bar dimensions are compared for the materials copper and aluminum to predict the suitable equivalent dimensions for the same ampacity level and within the allowable temperature rise to reduce the cost of panel.

Oil-paper insulation will inevitably endure impulse voltage with a superimposed dc voltage (superimposed voltage) because of introduced lightning or switching, which can induce charge accumulation and trigger flashover during the operation of a converter transformer. Temperature rise is also a nonnegligible factor that can significantly influence the performances of oil-paper insulation. This paper aims to reveal the effects of ambient temperature and superimposed voltage on surface charge and flashover behaviors in an oil-paper insulation system. Surface potential decay (SPD) experiments were performed under superimposed voltage with various polarity and amplitude combinations and at the temperature ranging from 20 °C to 80 °C. The results show that the initial surface potential and decay rate increase as the amplitude of the impulse voltage increases at 20 °C. The initial surface potential declines, and the process of SPD is accelerated at higher temperatures because of the increased concentration of shallow traps. Subsequently, flashover tests were conducted under superimposed voltage. It is found that flashover occurs after applying superimposed voltages even with a rather low dc voltage. In addition, the dc voltage component is primarily responsible for flashover. Weibull results also indicate that it is prone to trigger flashover at higher temperatures, because thermal excitation helps more carriers to escape from deep traps and participate in the process of flashover. Accordingly, the insulation characteristics of oil-paper system can be significantly influenced by superimposed voltage and temperature, which should draw great concern among the power grid.

Herein, we successfully designed a ventilation system for a new 350-MW air-cooled turbogenerator based on a reasonable lectotype choice and optimization analysis. Fluid field and thermal analysis based on computational fluid dynamics were performed to guide the optimization of cooling structures and ensure temperature rise under the limit of insulation grade B. The measured values obtained from recent factory assembly-type testing were found to coincide with the design expectations for generator efficiency and temperature rise. The results confirmed the feasibility of a multi-chamber forward-flow cooling path for 400-MVA-class air-cooled generators.

Fast charging of lithium-ion batteries is an essential problem that constrains the large-scale deployment of electric vehicles. To solve this problem, a new charging strategy is proposed in this paper. Three original contributions are made in this paper: 1) development of a novel multistage constant heating rates optimization method that reduces both the charging time and charging temperature increase, with the tradeoff between the charging time and charging temperature increase analyzed using the genetic algorithm (off-line strategy); 2) reduction of the charging time via ensuring a state of charge region by balancing the charge capacity and charge time; and 3) demonstration that the proposed method can be used under different temperatures by comparing the proposed method to the average constant current constant voltage (CCCV) under different temperatures; the comparison results suggest that the charging time of proposed method is reduced by 1.9%, 5.3%, 8.56%, and 9.54% compared to the average CCCV method under ambient temperature, 10 °C, 25 °C, and 40 °C, respectively. Moreover, the proposed method temperature rise is reduced by 48.6%, 28.3%, 67.3%, and 17.9% compared to the average CCCV method under ambient temperature 10 °C, 25 °C, and 40 °C, respectively.

Background: To evaluate temperature changes in pulp chamber during light activation of newer pulp- capping materials and composite resin using light-emitting diode. Materials and Methods: A standardized Class I cavity was prepared in 80 extracted, intact, noncarious mandibular first molars, keeping remaining dentin thickness of 0.5 mm. The teeth were divided into four groups of 20 teeth each. Following this, apical third of the mesial root of each tooth was cut and a K type thermocouple attached to digital thermometer was inserted into pulp chamber from the sectioned mesial root. Whole assembly with teeth was suspended in water bath with constant temperature at 37°C. The previously divided teeth in four groups, were lined with Calcimol LC (Group A), Activa (Group B), TheraCal LC (Group C), and Ionoseal (Group D), followed by 3 increments of Filtek Z350 × T universal restorative. The temperature rise following light activation of pulp-capping material, bonding agent, and composite was noted. Results: The temperature rise in the pulp chamber after light activation of Activa was highest among all pulp-capping materials, followed by teeth lined with Calcimol LC, Ionoseal, and least in teeth with TheraCal LC. Conclusions: Temperature rise in the pulp chamber after light activation of newer pulp-capping materials and composite was below critical threshold for irreversible pulpal damage. Among all the pulp-capping materials, TheraCal LC showed lowest temperature rise in pulp chamber.

Emergency motor switch-on happens occasionally while operating a doublesquirrel- cage motor at full supply voltage with the rotor blocked (e.g., in coal mills). After releasing the blockage, the by now heated motor is started up again. However, the mechanical stress caused by the increased temperature poses considerable hazards to the squirrel-cage winding. This paper presents a double-cage induction motor model for analysis of thermal fields in transient operation. The thermal field for the rotor of a doublesquirrel- cage motor of soldered or cast structure, operating in the conditions described, has been calculated in the present paper using a thermal network method. Measurement results have been presented for the double-squirrel-cage winding temperature for a soldered cage construction in the blocked rotor state.

International audience; The aim of this study was to determine the interest in and relevance of the use of infrared thermography, which is a non-invasive full-field surface temperature measurement technique, to characterize the heterogeneous heating caused by ultrasound in biological tissue. Thermal effects of shear wave elastography, pulse Doppler and B-mode were evidenced in porcine tissue. Experiments were performed using a high-frequency echography Aixplorer system (Supersonic Imagine, Aix-en-Provence, France). For all three modes, ultrasound was applied continuously for 360 s while the temperature at the sample surface was recorded with a Cedip Jade III-MWIR infrared camera (Flir, Torcy, France). Temperature changes were detected for the three modes. In particular, “heat tunnels” crossing the sample were visualized from the early stages of the experiment. Heat conduction from the transducer was also involved in the global warming of the sample. The study widens the prospects for studies on tolerability, potentially in addition to classic approaches such as those using thermocouples.

International audience; Crack nucleation issue is addressed in a comprehensive micromechanics-based framework allowing to bridge the 2D model with the more realistic 3D representation of a crack. The sudden and abrupt nature of the nucleation process argues in favour of adiabatic conditions rather than isothermal so that the formulation of the energy balance is formulated in terms of internal energy instead of Helmholtz free energy. The proposed theory provides the mean to evaluate the temperature rise as a function of the created entropy at the microscopic scale and the internal energy crack density at the macroscopic one.

Background: The aim of this study was to investigate cuspal deflection caused by material shrinkage and temperature rise occurring in the pulp chamber during photopolymerization. The aim of this study was also to investigate the effect of flowable and packable bulk-fill composites on cuspal deflection occurring in mesio-occlusal&ndash, distal (MOD) cavities restored through the bulk-fill or through the incremental layering technique. Additionally, mechanical and thermal properties of bulk-fill composites were considered. Methods: Two bulk-fill composites (high-viscosity and low-viscosity), largely differing in material composition, were used. These composites were characterized through linear shrinkage and compressive test. Cuspal deformation during restoration of mesio-occlusal&ndash, distal cavities of human premolars was evaluated using both the bulk-fill and the incremental layering techniques. Temperature rise was measured through thermocouples placed 1 mm below the cavity floor. Results: Shrinkage of the flowable composite was significantly higher (p &lt, 0.05) than that of packable composite, while mechanical properties were significantly lower (p &lt, 0.05). For cusp distance variation, no significant difference was observed in cavities restored through both restorative techniques, while temperature rise values spanned from 8.2 &deg, C to 11.9 &deg, C. Conclusions: No significant difference in cusp deflection between the two composites was observed according to both the restorative techniques. This result can be ascribed to the Young&rsquo, s modulus suggesting that the packable composite is stiffer, while the flowable composite is more compliant, thus balancing the cusp distance variation. The light curing modality of 1000 mW/cm2 for 20 s can be considered thermally safe for the pulp chamber.

Background: Deep dental cavities can be restored through a single step according to the bulk-fill technique. Due to the great amount of resin to be cured, a main concern is the temperature rise occurring in the pulp chamber, potentially higher than that developed through the incremental layering technique. Temperature rise of bulk-fill composites have been evaluated. Methods: Bulk-fill composites, differing in material composition and viscosity, were used. Maximum temperature and temperature rate occurring in the composites were measured. Mesio-occlusal-distal cavities of human premolars were restored through the bulk-fill or the incremental layering techniques, and peak temperature and temperature rate occurring in the dentin, 1 mm below the cavity floor, were evaluated. Results: Temperature peak and temperature rise of flowable composites were significantly higher (p &lt, 0.05) than packable composites. For both the techniques, higher temperature peaks were recorded in the dentin for flowable composites. Peak temperatures higher than 42 &deg, C were recorded for the incremental layering technique considering flowable composites. Conclusions: For all the composites, the light curing modality of 1000 mW/cm2 for 20 s can be considered safe if the bulk-fill technique is performed. Instead, for the incremental layering technique, potentially dangerous temperature peaks have been recorded for flowable composites.

Recent uptake in the use of lithium-ion battery packs within electric vehicles has drawn significant attention to the selection of busbar material and corresponding thickness, which are usually based on mechanical, electrical and thermal characteristics of the welded joints, material availability and cost. To determine joint behaviour corresponding to critical-to-quality criteria, this study uses one of the widely used joining technologies, ultrasonic metal welding (UMW), to produce tab-to-busbar joints using copper and aluminium busbars of varying thicknesses. Joints for electrical and thermal characterisation were selected based on the satisfactory mechanical strength determined from the T-peel tests. Electrical contact resistance and corresponding temperature rise at the joints were compared for different tab-to-busbar joints by passing current through the joints. The average resistance or temperature increase from the 0.3 mm Al tab was 0.6 times higher than the 0.3 mm Cu[Ni] tab, irrespective of busbar selection.

Multi-layer, metallo-dielectric structures (screens) have long been employed as electromagnetic band filters, either in transmission or in reflection modes. Here we study the radiation energy not transmitted or reflected by these structures (trapped radiation, which is denoted—absorption). The trapped radiation leads to hot surfaces. In these bi-layer screens, the top (front) screen is made of metallic hole-array and the bottom (back) screen is made of metallic disk-array. The gap between them is filled with an array of dielectric spheres. The spheres are embedded in a dielectric host material, which is made of either a heat-insulating (air, polyimide) or heat-conducting (MgO) layer. Electromagnetic intensity trapping of 97% is obtained when a 0.15 micron gap is filled with MgO and Si spheres, which are treated as pure dielectrics (namely, with no added absorption loss). Envisioned applications are anti-fogging surfaces, electromagnetic shields, and energy harvesting structures.

The effects of die radius in a streamlined die on design factors, such as the distribution of strain, stress, temperature, damage, and drawing force of a wire, were investigated during wire drawing for a better understanding of streamlined die and improvement in drawing quality of the wire. A numerical simulation was performed with the die radius of the streamlined die. The behavior of the design factors of the drawn wire fabricated by the streamlined die was different from that of the conventional die and was highly dependent on the die radius. The different behaviors of the design factors with the die radius can be explained by the frictional work and redundant work of the wire with die angle. The temperature rise and drawing force were high at a greater die radius because of the great frictional stress and heating effect stemming from the high contact length of the wire and die. Meanwhile, the higher redundant work at the surface area with decreasing die radius led to higher strain inhomogeneity, effective stress, damage value, temperature rise, and drawing force due to the abrupt change in the metal flow of the wire stemming from the high die angle. After the optimization of several design factors with die radius, it was concluded that the optimum IDR values ranged from 0.14 to 0.18, indicating that a streamlined die with a radius of 70 to 90 mm was the most suitable in the present process condition. In particular, the damage value of the wire was reduced in this range of die radii compared to the conventional die.

WOS: 000400956500004, PubMed ID: 30894999, Background/purpose: Nowadays, laser systems play crucial roles in endodontic treatments. Therefore, these systems should be investigated in terms of parameters that may prevent periodontal tissues damages during laser irradiation. In this context, the purpose of this study was to evaluate temperature rises during the application of different power levels of potassium titanyl phosphate (KTP) and neodymium-doped:yttrium aluminum garnet (Nd:YAG) lasers to external primary root canals. Materials and methods: Sixty primary mandibular molars were selected and chemomechanical preparation was performed. KTP laser treatment was applied to 30 of these 60 samples and the remaining 30 received Nd:YAG laser treatment. The teeth samples received laser application (KTP or Nd:YAG) at three different power levels (1 W, 1.5 W, and 2 W, respectively, applied to 10 samples from each group). Nine holes were drilled (1 mm in diameter) through the level of the coronal, middle, and apical third of each tooth canal to provide entry for a Type L thermocouple wire, which was used to measure temperature changes. Data were assessed with two-way analysis of variance and the Tukey test. Results: All power levels indicated statistically significant differences between Nd:YAG and KTP laser systems (P < 0.05). Moreover, the same regional (apical, middle, and coronal) comparisons performed between Nd:YAG and KTP laser systems showed statistically significant differences (P < 0.05). Conclusion: All parameters of KTP laser indicated lower temperature rises than Nd:YAG laser. Therefore, KTP laser may be preferable to protect the periodontal tissues from harmful thermal effects during the endodontic treatment of primary root canals. Copyright (C) 2016, Association for Dental Sciences of the Republic of China. Published by Elsevier Taiwan LLC.

White etching layer (WEL) is a frequently observed microstructural phenomenon in rail surface, formed during dynamic wheel/rail contact. It is considered as one of the main initiators for rolling contact fatigue cracks. There are several hypotheses for the formation mechanism of WEL. However, due to the complicated wheel/rail contact conditions, none is directly proven. Currently, the most popular hypotheses refer to either formation of martensitic WEL by phase transformations or formation of nanocrystalline ferritic WEL by severe plastic deformation. In this work, WEL formation by martensitic transformation in R260Mn grade pearlitic rail steel was simulated by fast heating and quenching experiments. Microstructural characteristics of the simulated WEL and WEL observed in a field rail specimen were characterized by microhardness, optical microscopy, scanning electron microscopy and electron backscatter diffraction. Microstructures of the two WELs were compared and similarities in morphology were identified. Numerical simulation shows the possible temperature rise up to austenitizing temperatures. Combining comparisons of experimental simulation with observation of WEL in the rail and the thermodynamic calculations, the hypothesis for WEL formation via martensitic transformation is supported.

Aim: To compare the rise in temperature using trephines over conventional ones during bone site preparation. Setting and Design: An-vitro, evaluative study Materials and Methods: Twenty implant sites were prepared using pilot drill up to depth of 10 mm on bovine femoral bone. In first part, no irrigation was used. Five sites were prepared using conventional drill of 2.8 mm, and other five were prepared with help of trephine drills. On completion of each drill, infrared thermometer was used to measure temperature on both the drill tip and the shaft. The same procedure was repeated with bone immersed in saline. Statistical Analysis Used: Student t test was used to evaluate the significance of difference. Result: Study showed that the temperature rise at drill tip was significantly higher for trephine drill (52.98 ± 1.67 °C) than conventional drills (48.20 ± 0.67 °C), however the temperature difference in trephine and conventional drills was statistically insignificant. Conclusion: The temperature increase was more distributed in conventional drills than trephine. Copious irrigation is thus mandatory for trephine drills. Intermittent drilling is preferred with conventional drills.

Piezoelectric devices are widely used in oral surgical procedures, including implant site preparation. However, little is known about the influence of working movement on temperature elevation in bone. The aim of this study was to assess the effects of two different working cycles on temperature elevation during piezoelectric implant site preparation. Sixty osteotomies at a depth of 10 mm were performed on bone blocks of bovine ribs using a piezoelectric tip with external irrigation (IM1s, Mectron Medical Technology, Carasco, Italy). A mechanical positioning device was used to guarantee reproducible working and measuring conditions. Two different working cycles, of 4 and 6 s, respectively, were tested, including both longitudinal and rotational movements. Temperature was recorded in real time with a fiber optic thermometer and applied pressure was maintained under 150 g. For each test, the highest recorded temperature (Tmax) and the mean temperature recorded from 30 s before to 30 s after the highest recorded temperature (T&plusmn, 30) were extrapolated. Tests duration was also recorded. Both Tmax and T&plusmn, 30 were significantly higher in the &lsquo, 6 s cycles&rsquo, group than the &lsquo, 4 s cycles&rsquo, group (42.44 &plusmn, 7.3 &deg, C vs. 37.24 &plusmn, 4.6 &deg, C, p = 0.002, 37.24 &plusmn, C vs. 33.30 &plusmn, 3.3 &deg, C, p = 0.003). Test duration was also significantly higher using 6 s cycles compared to 4 s cycles (143.17 &plusmn, 29.4 s vs. 119.80 &plusmn, 36.4 s, p = 0.002). The results of this study indicate that working cycles of 4 s effectively reduce heat generation and working time during piezoelectric implant site preparation.

Background: Management of caries using minimally invasive dentistry is prevalent in dentistry today. A newer technology is to disinfect/sterilize caries in depth of the dental tissue with diode laser. However, to have a bactericidal effect, increased energy density of light amplification by stimulated emission of radiation (LASER) may be required which in turn may lead to higher thermal load causing harmful effects on vital pulpal tissue. Aims: The aim was to evaluate temperature rise and efficacy of cavity disinfection with diode laser. Materials and Methods: Twenty permanent molar teeth with dentinal caries were randomly assigned into two groups on the basis of LASER irradiation: Group 1 – at 1 W, Group 2 – at 2 W. The elevation of subsurface temperature during irradiation was measured using thermocouples positioned in the center of a prepared cavity. Dentinal samples were collected before and after disinfection of the cavity. These samples were subjected to microbiological evaluation for Streptococcus mutans on Mutans-Sanguis agar and Lactobacilli on Rogosa agar. Statistical Analysis: Log transformed “t”-test and paired “t“-test were used for the statistical analysis. Results: Although the reduction in microbial count revealed insignificant difference at two different wattages, the rise in temperature with 1 W was less than that with 2 W. Conclusion: Efficacy of 1 W and 2 W is similar, but 1 W causes less thermal changes, thus, 1 W is recommended over 2 W.

The aim of this research was to compare the pulp temperature (PT) rise induced by four light-emitting diode light-curing units (LED LCUs) (Bluephase 20i, Demi Ultra, SPEC 3, and Valo) in different curing modes. Immediately after extraction, the pulp chamber of 11 premolars was accessed from the palatal cervical third of the crown for insertion of fiber Bragg grating (FBG) sensors for temperature measurement and kept in a 37.0&deg, water bath. The teeth were then submitted to a random sequence of curing modes with four irradiations at 30 s intervals. Care was taken to ensure complete pulp temperature reset between curing modes. The curing modes were classified as high-energy (above 80 J/cm2) or low-energy (below 40 J/cm2) according to the total energy density delivered. Statistical analysis was performed with repeated ANOVA measures and Pearson&rsquo, s correlation for the association between energy density and temperature variation. The significance level was set to 0.05. All curing units promoted a statistically significant PT rise (p &lt, 0.01). After four emissions, the PT rise was higher than 5.0 &deg, C for the high-energy curing modes. The low-energy modes induced approximately a 2.5 &deg, C rise. A strong positive correlation was found between energy density and PT increase (R = 0.715, p = 0.01). Exposure of intact premolars to LED LCUs induced significant and cumulative PT rise. Curing modes emitting high energy densities produced higher PT variations. Radiant exposure was positively correlated to PT variation.

Erbium, chromium: yttrium, scandium, gallium, garnet (ErCr:Ysgg) lasers have been frequently used in oral surgical procedures and are almost seen as alternatives to diode lasers. The aim of this comparative study was to analyze in an animal model the thermal elevation induced by ErCr:Ysgg and diode lasers in soft tissue and bone.Thirty freshly dissected sheep mandibles containing bone and soft tissue were divided into 120 equal parts. Gallium-aluminum-arsenide (Ga-Al-As) diode laser (λ=940 nm) with 1, 2 and 5 W output powers and ErCr:Ysgg laser (λ=2780 nm) with 2.75, 4.5 and 6 W output powers were used on soft and bone tissues separately for 3 seconds with point application. Mean temperature values before and after application of the lasers were compared in soft tissue and bone.The minimum mean temperature value was observed with 2.75 W ErCr:Ysgg laser while irradiation with 5 W diode laser created the maximum values (p0.05).ErCr:Ysgg laser (λ=2780 nm) with 2.75 W power generates low levels of heat compared to diode lasers and may provide safer surgery in soft and bone tissues without destructive effects of temperature increase.Erbiyum, krom: itriyum-skandiyum-galyum-garnet (ErCr:Ysgg) lazerler oral cerrahi işlemlerde yaygın biçimde kullanılmakta olup, diyot lazerlere neredeyse alternatif olarak düşünülmektedir. Bu çalışmanın amacı, ErCr:Ysgg lazerler ve diyot lazerlerin kemik ve yumuşak dokuda meydana getirdikleri sıcaklık artışının bir hayvan modeli üzerinde karşılaştırılmasıdır.Otuz adet koyun mandibulası her biri kemik ve yumuşak doku içeren 120 eşit parçaya bölünmüştür. Yumuşak doku ve kemik üzerine ayrı ayrı olacak biçimde, 3 saniye süre ile 1, 2 ve 5 W çıkış güçlerinde galyum-aluminyum-arsenid (Ga-Al-As) diyot lazer (λ=940 nm) ve 2,75, 4,5 ve 6 W çıkış güçlerinde ErCr:Ysgg lazer (λ=2780 nm) uygulaması gerçekleştirilmiştir. Uygulama öncesi ve uygulamadan hemen sonraki ortalama sıcaklık değerleri karşılaştırılarak veriler analiz edilmiştir.En düşük ortalama sıcaklık değeri 2,75 W gücünde Er,Cr:YSGG lazer uygulamasında gözlenirken, 5 W gücünde diyot lazer uygulamasının en yüksek sıcaklık değerini oluşturduğu görülmüştür (p0,05).ErCr:Ysgg lazerin (λ=2780 nm) 2,75 W güçte uygulanması, diyot lazerlerle kıyaslandığında daha düşük sıcaklık artışına neden olmakta ve sıcaklık artışının neden olabileceği yıkıcı etkiler bakımından, kemik ve yumuşak doku cerrahilerinde daha güvenli sonuçlar sağlayabileceği düşünülmektedir.

The aim of this study was to evaluate the effect of different peak wavelengths (450nm, 468nm and 490nm) of experimental LEDs on hardness, elastic modulus, degree of conversion and temperature rise of a microhybrid resin composite – Venus® (Heraeus Kulzer). Hardness and elastic modulus were determined by nanoindentation technique (n=5), degree of conversion was measured by FTIR (n=5) and temperature rise was measured with a thermistor (n=30). Data were submitted to ANOVA and multiple comparisons tests (α=0.05). Mechanical properties and degree of conversion (p

Recently, the engineering structural ceramics as friction and wear components in manufacturing technology and devices have attracted much attention due to their high strength and corrosion resistance. In this study, the tribological properties of Si3N4/Si3N4 sliding pairs were investigated by adding few-layer graphene to base lubricating oil on the lubrication and cooling under different experimental conditions. Test results showed that lubrication and cooling performance was obviously improved with the addition of graphene at high rotational speeds and low loads. For oil containing 0.1 wt% graphene at a rotational speed of 3000 r&middot, min&minus, 1 and 40 N loads, the average friction coefficient was reduced by 76.33%. The cooling effect on Si3N4/Si3N4 sliding pairs, however, was optimal at low rotational speeds and high loads. For oil containing 0.05 wt% graphene at a lower rotational speed of 500 r&middot, 1 and a higher load of 140 N, the temperature rise was reduced by 19.76%. In addition, the wear mark depth would decrease when adding appropriate graphene. The mechanism behind the reduction in friction and anti-wear properties was related to the formation of a lubricating protective film.

Objectives Light-curing of resin-based materials (RBMs) increases the pulp chamber temperature, with detrimental effects on the vital pulp. This in vitro study compared the temperature rise under demineralized human tooth dentin during light-curing and the degrees of conversion (DCs) of three different RBMs using quartz tungsten halogen (QTH) and light-emitting diode (LED) units (LCUs). Materials and Methods Demineralized and non-demineralized dentin disks were prepared from 120 extracted human mandibular molars. The temperature rise under the dentin disks (n = 12) during the light-curing of three RBMs, i.e. an Ormocer-based composite resin (Ceram. X, Dentsply DeTrey), a low-shrinkage silorane-based composite (Filtek P90, 3M ESPE), and a giomer (Beautifil II, Shofu GmbH), was measured with a K-type thermocouple wire. The DCs of the materials were investigated using Fourier transform infrared spectroscopy. Results The temperature rise under the demineralized dentin disks was higher than that under the non-demineralized dentin disks during the polymerization of all restorative materials (p < 0.05). Filtek P90 induced higher temperature rise during polymerization than Ceram.X and Beautifil II under demineralized dentin (p < 0.05). The temperature rise under demineralized dentin during Filtek P90 polymerization exceeded the threshold value (5.5℃), with no significant differences between the DCs of the test materials (p > 0.05). Conclusions Although there were no significant differences in the DCs, the temperature rise under demineralized dentin disks for the silorane-based composite was higher than that for dimethacrylate-based restorative materials, particularly with QTH LCU.

The dynamic response and microstructure evolution of oxygen-free high-conductivity copper in a shaped charge liner are investigated through microstructural examination of a soft-recovery EFP. Adiabatic shear bands and voids which is the failure original of copper EFP can be observed in the rear part of the projectile. Numerical simulation results illustrate that the highest plastic strain reaches about 2.9 which can fully accommodate the grains deformation of copper EFP during the formation process at strain rates of the order of 104s−1. Theoretical calculation results indicate that the highest temperature increase of EFP caused by shock wave and plastic deformation can reach 747K, which is 0.55T m (where T m is the melting temperature of copper). The main body of the EFP undergoes completely dynamic recrystallisation, and the average size of the refined grains significantly decreases to approximately 10µm. A slight increase in grain size occurs mainly away from the center and extends towards the head and rear sections of the EFP. During the DRX process, the dislocation movement is believed to be the controlling mechanism significantly refining the microstructure.

The estimation of cage slips and ball slips, i.e. skidding, in ball bearings used for the main shafts of jet engines, gas turbines, and turbo machines is necessary to clarify the phenomenon of wear and smearing in the bearings. Therefore, in this study, a new method for estimating skidding has been developed by taking lubricating oils to be non-Newtonian fluids, by considering oil temperature rises caused by slips occurring in the ball-to-raceway contacts, and by considering the equilibrium of forces acting between the cage and balls. These factors were not taken into consideration in Harris’ theory. To establish the adequacy of our analysis, analytical data of our study have been compared against experimental data published by Poplawski. Our analysis can also calculate oil film thicknesses and traction coefficients under skidding conditions.

Contact temperature in fretting has a significant effect on the process. Since direct temperature measurement is impossible, analytical models are required to estimate the friction-induced temperature rise for the optimization of the system performance. The objective of this work is to present models for the micro and macro thermal constriction phenomena in fretting. The effect of the process parameters is examined. The analysis showed that the contact temperature rise can be quite significant when the contact pressure-to-hardness ratio is high and when the material thermal conductivity is low. The paper is concluded with recommendations for future work. © 2010 Elsevier Ltd. All rights reserved.

The time dependence of the temperatures T(z, t) has been measured along the thickness direction z in several drilled holes in a superconducting bulk during pulsed field magnetization (PFM) and the heat generation and heat transfer in the bulk have been discussed. In the previous paper [H. Fujishiro, S. Kawaguchi, K. Kakehata, A. Fujiwara, T. Tateiwa, T. Oka, Supercond. Sci. Technol. 19 (2006) S540], we calculated the T(z, t) profiles in the bulk by solving a three-dimensional heat-diffusion equation to reproduce the measured T(t) on the bulk surface; the heat generation took place adiabatically and the calculated T(z, t) was isothermal along the z direction. In this study, the measured T(z, t) at the top surface was higher than that at the bottom surface just after the pulse field application at t < 0.5 s, and then became isothermal with increasing time. These results suggest that the magnetic flux intrudes inhomogeneously into the bulk from the edge of the top surface and the periphery at the early stage. The inhomogeneous magnetic flux intrusion and the flux trap during PFM change depending on the strength of the pulsed field and the pulse number in the successive pulse field application.