• Journal of Magnetics
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• v.15 no.3
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• pp.138-142
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• 2010

This paper reports the development of an analysis method in a synchronous reluctance motor (SynRM) using the finite element method (FEM) coupled with the electromagnetic field of the Preisach model, which represents an additional thermal source due to hysteresis loss and a thermal field. This study focused on thermal analysis relative to hysteresis and copper losses in a SynRM.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.1
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• pp.66-73
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• 2017

In this work, graphene platelets were introduced into wax in an automotive electronic controlled thermostat for the purpose of enhancing its thermal-conductive property and improving response performance. Graphene content ranging from 10 % to 20% was added into and mixed with the wax to investigate the effect of graphene amounts on the performance of an automotive electronic controlled thermostat in terms of response time, hysteresis and melting temperature. The experimental results revealed that graphene in wax contributed to a reduction in the response time and hysteresis of an automotive electronic controlled thermostat. As a consequence, important improvement in thermal sensitivity, full lift, melting temperature and hysteresis were obtained. The thermal response of wax with graphene content of 20 % was improved by 25 %, as compared to that of wax with Cu content of 20 %. Hysteresis of wax with graphene was reduced by $0.6^{\circ}C$ as compared to that of wax with Cu content. The melting temperature of wax is lowered and hysteresis is also improved with increased graphene content of wax in an electronic controlled thermostat. We hope that this study can help further the transition of nano-fluid technology from small-scale research laboratories to industrial application in the automotive sector.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.40-46
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• 2001

The thermal stability of $Al_2TiO_{5}$ ceramics was improved by formation of solid solution with MgO, such as $MgAl_2O_4$ spinel through electrofusion in an arc furnance, and by limitation of grain size and microcracks with $SiO_2$, $ZrO_2$ and ${\alpha}$-$Al_2O_3$. The low thermal expansion properties of $Al_2TiO_{5}$ composites show the thermal hysteresis curves due to the strong anisotropy of $Al_2TiO_{5}$. These phenomena are explained by the opening and closing of microcracks. The relation between thermal hysteresis, microstructures and sintering temperature were studied by dilatometry.

• The Korean Journal of Ceramics
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• v.5 no.4
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• pp.414-418
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• 1999

The synthesis of polycrystalline $Al_2TiO_5$ ceramics with low thermal expansion by fusion in an electric arc furnance was investigated. The thermal expansion curves of $Al_2TiO_5$ ceramics were lowered because of microcracks caused by the strong thermal expansion anisotropy of the crystal axes and were accompanied by hysteresis curves. These phenomena are explained by the opening and closing of microcracks. The difference in microcracking temperatures of dilatometric cooling curves in the range of 400~$620^{\circ}C$ is caused by the difference in sintering temperature, grain size and stabilization status.

• Journal of Power System Engineering
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• v.5 no.3
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• pp.48-55
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• 2001

In many applications. rubber components undergo dynamic stresses or deformations of fairly large magnitude. Since rubbers are not fully elastic, a part of the mechanical energy is converted into heat due to the hysteresis loss. Heat generation without adequate heat dissipation leads to heat build up. i. e. internal temperature rise. The purpose of this paper is to predict temperature rise caused by the hysteresis loss, in a rubber pad subjected to complex dynamic deformation. In this unsteady thermal analysis, the temperature distributions of track components are displayed in contour shapes and the temperature variations of some important nodes are represented graphically with respect to the running time of the tank.

• The Korean Journal of Ceramics
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• v.2 no.4
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• pp.246-250
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• 1996

The thermomechanical properties of materials from the system Al2O3-SiO2-TiO2(Tialite-Mullite) were investigated by correlating the thermal expansion anisotroypy, flexural strength and Young's modulus with grain size and atructural microcracking during cooling. Microcracking temperatures were determined by measuring the hysteresis of the thermal expansion anisotropy with dilatometry. Single phase Aluminium Titanate is a low strength material, while composites with more than 10 vol% mullite as second phase enhance the Young's modulus, thermal expansion coefficient and room temperature strength.

• Journal of the Korean Chemical Society
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• v.62 no.2
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• pp.106-112
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• 2018

Ice-binding proteins have an affinity for ice. They create a gap between the melting and freezing points by inhibiting the growth of ice, known as thermal hysteresis (TH). Interestingly, moderately active LeIBP and hyperactive FfIBP are almost identical in primary and tertiary structures, but differ in TH activity. The TH of FfIBP is tenfold higher than that of LeIBP, due to a subtle difference in their ice-binding motifs. To further evaluate the difference in TH, the interactions were investigated by ice-etching and molecular docking. Ice-etching showed that FfIBP binds to the primary and secondary prism, pyramidal, and basal planes; previously, LeIBP was found to bind to the basal and primary prism planes. Docking analysis using shape complementarity (Sc) showed that the hyperactive FfIBP had higher Sc values for all four ice planes than LeIBP, which is comparable with TH. Docking can be used to describe the hyperactivity of IBPs.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.11
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• pp.59-65
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• 2015

By harnessing the thermal hysteresis behavior of vanadium dioxide($VO_2$), we demonstrated multi-resistance states in a two-terminal electronic device based on a $VO_2$ thin film by using a 966nm infrared laser diode as an excitation light source for resistance modulation. Before stimulating the device using 966nm laser pulses, the thermal hysteresis behavior of the device resistance was measured by using a temperature chamber. After that, the $VO_2$ device was thermally biased at ${\sim}71.6^{\circ}C$ so that its temperature fell into the thermal hysteresis region of the device resistance. Six multi-states of the device resistance could be obtained in the fabricated $VO_2$ device by five successive laser pulses with equal 10ms duration and increasing power. Each resistance states were maintained while the temperature bias was applied. And, the resistance fluctuation level was within 2.2% of the stabilized resistance and decreased down to less than 0.9% of the stabilized resistance 5s after the illumination.

• Journal of the Korean Ceramic Society
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• v.35 no.10
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• pp.1061-1069
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• 1998

The thermal instability of Al2TiO5 Ceramics was contrlled by solid solution with MgO SiO2 and ZrO2 through electrofusion in an arc furnace. The thermal expansion properties of Al2TiO5 composites show the hysteresis due to the strong anisotropy of The crystal axes of these material. These phenomena are ex-plained by the opening and closing of microcracks. The difference in microcracking temperatures e.g 587.6(ATG2), 405.9(ATG3) and 519.7$^{\circ}C$(ATG4) is caused by the difference in grain size and stabilizer type. The thermal shock behaviour under cyclic conditions between 750-1400-75$0^{\circ}C$ show no change in mi-crostructure and phase assemblage for all three stabilized specimens. After the thermal loading test at 110$0^{\circ}C$ for 100hrs. ATG1 and ATG2 materials decomposes completely to its components corundum and ru-tile in both cases. However with approximatelly 20% retention of the Al2TiO5 Thus in order to prevent decomposition of the stabilized material in the critical temperature range 800-130$0^{\circ}C$ it must be traversed within a short period of time.

• Journal of the Korean Society for Heat Treatment
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• v.9 no.2
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• pp.147-158
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• 1996

Generally, analytical consideration on the behaviour of metallic structures during quenching process, and analysis on the thermal stress and deformation after heat treatment are very important in presumption of crack and distorsion of quenched material. In this study a set of constitute equations relevant to the analysis of thermo elasto-viscoplastic materials with strain hysteresis during quenching process way presented on the basis of contimuum thermo-dynamics mechanics. The thermal stresses were numerically calculated by finite element technique of weighted residual method and the principle of virtual work. In the calculation process, the temperature depandency of physical and mechaniclal properties of the material in consideration. On the distribution of elasto-viscoplastic thermal stresses according to radial direction, axial and tangential stress are tensile stress(50MPa, 1.5GPa and 300MPa) in surface and compressive stress(-1.2GPa, -1.14GPa and -750MPa) in the inner part on the other hand, radial stress is tensile stress(900MPa) in area of analysis. According to axial direction, tangential stress gradients are average 60MPa/mm on the whole. The reversion of stress takes place at 11.5 to 16.8mm from the center in area of analysing.