• 한국기계가공학회지
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• 제13권4호
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• pp.50-55
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• 2014

Currently, flat cover glasses are widely applied to mobile devices. However, for a good design and for convenience of use, curved cover glasses are in demand. Thus, many companies are attempting to produce curved cover glasses using a shaving technique, but the production efficiency is very low. Therefore, a molding technique has been adopted to increase the efficiency of curved glass production systems. For a glass molding system, a uniform temperature distribution of the mold is crucial to produce high-quality curved cover glasses. Before setting the heating conditions of the molding system for a uniform temperature distribution by a thermal analysis, verification is required. Therefore, in this study, temperature measurements were conducted for a prototype molding system and the experimental results were compared with simulation computations. The temperatures of the heating block surface were in good agreement with the computational results for transient and steady conditions.

• 한국전기전자재료학회논문지
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• 제36권1호
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• pp.42-48
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• 2023

Abstract: In this study, an induction heating system using resonance is developed to remove remaining moisture and contaminations which could be generated during fabricating secondary batteries. This system is composed of power supply and induction coil. Power supply needs an oscillator, zero crossing detection, frequency tracking function, and induction coil needs a dummy coil to obtain a uniform temperature distribution. It is very important to obtain a uniform heating temperature distribution of battery cell case in the induction heating system before pouring electrolyte into battery cell. Experimental results show a temperature distribution deviation of below 1℃ in the external position of battery cell cases. As well, the temperature of battery cell itself shows distribution of 40℃±3℃.

• Nuclear Engineering and Technology
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• 제55권11호
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• pp.3983-3995
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• 2023

In fast reactors, restructuring of the fuel micro-structure driven by high temperature and high temperature gradient can cause the formation of columnar grains. The non-spheroidal shape and the non-uniform temperature field in such columnar grains implies that standard models for fission gas diffusion can not be applied. To tackle this issue, we present a reduced order model for the fission gas diffusion process which is applicable in different geometries and with non-uniform temperature fields, maintaining a computational requirement in line with its application in fuel performance codes. This innovative application of reduced order models as meso-scale tools within fuel performance codes represents a first-of-a-kind achievement that can be extended beyond fission gas behaviour.

• 복식
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• 제66권6호
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• pp.110-121
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• 2016

The purpose of this study is to develop high value-added uniform design in response to climate change, and produce high sensitivity uniforms that conserve the energy of its wearers. The scope of the study encompassed entire production stage from the product planning stage to developing a prototype to collecting consumer ratings to securing intellectual property. The results of the study are as follows. First, the material was developed that maximizes insulation by replicating human body heat radiation and raising the temperature by 5 degree Celsius. Second, through Time to Market system, a luxurious synthetic wool material was developed, and warm effect was achieved. Third, pattern design engineering for easy movement and design development allowed the realization of uniform design that is compatible indoors and outdoors as well as respond to highly active climate change. Fourth, Fifth, the developed design was registered and intellectual property rights were obtained.

• 열처리공학회지
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• 제28권4호
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• pp.200-205
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• 2015

Effects of austenite on the uniform corrosion in the solution of $1\;N\;H_2SO_4$ were investigated through the electrochemical polarization test. Two phases structures of martensite and austenite were obtained by annealing treatment at the range of $500^{\circ}C{\sim}700^{\circ}C$ for 10min. in 70% cold-rolled 202 stainless steel. Volume fraction of reversed austenite increased rapidly with an increase of annealing temperature. Uniform Corrosion was occur mainly on martensite phase in 202 austenitic stainless steel with two phase of austenite and martensite. Corrosion current density increased with an increase of volume fraction of austenite, therefore uniform corrosion was affected by volume fraction of austenite

• 한국초전도ㆍ저온공학회논문지
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• 제19권3호
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• pp.44-48
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• 2017

Current lead is a device that connects the power supply and superconducting magnets. High temperature superconductor (HTS) has lower thermal conductivity and higher current density than normal metal. For these reasons, the heat load can be reduced by replacing the normal metal of the current lead with the HTS. Conventional HTS current lead has same cross-sectional area in the axial direction. However, this is over-designed at the cold-end (4.2 K) in terms of current. The heat load can be reduced by reducing this part because the heat load is proportional to the cross-sectional area. Therefore, in this paper, heat load was calculated from the heat diffusion equation of HTS current leads with uniform and non-uniform cross-sectional areas. The cross-sectional area of the warm-end (65K) is designed considering burnout time when cooling system failure occurs. In cold-end, Joule heat and heat load due to current conduction occurs at the same time, so the cross-sectional area where the sum of the two heat is minimum is obtained. As a result of simulation, current leads for KSTAR TF coils with uniform and non-uniform cross-sectional areas were designed, and it was confirmed that the non-uniform cross-sectional areas could further reduce the heat load.

• 한국화재소방학회논문지
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• 제11권3호
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• pp.15-23
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• 1997

In this study, the alumina for gas sensor was prepared by anodic oxidation. It was stable thermally and chemically, and pore diameter and pore distribution was uniform. And the shape of pore was cylinderical. The aluminum plate was carried out by the thermal oxidation, chemical polishing and electropolishing pretreatment. The pore diameter, pore size distribution, pore density and thickness of alumina was observed with the change of reaction temperature, electrolyte concentration and current density. As a results, It was able to use for carrier because alumina which was prepared by anodic oxidationhas uniform pore size distribution.

• 한국축산시설환경학회지
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• 제3권2호
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• pp.77-85
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• 1997

Recently, local swine producers are rapidly adopting the indoor production system which developed in foreign countries. However, this imported system is reported as not functioning properly because of different climate conditions. The objective of this project was to investigate the environment characteristics of a windowless delivery swine building. The parameters studied were the heating and cooling loads, the daily changes of indoor temperature and relative humidity, the horizontal and the vertical distributions of indoor temperature, and the effect of mist cooling on indoor temperature. From this study, the following are founded : 1. The maximum cooling and heating loads were - 317.0kcal/㎡$.$h and 336.5kal/㎡$.$h in summer and in winter. The large loads seems to be on account of inappropriate operations of ventilating fans. 2. The daily variations of relative humidity in indoor were smaller than those in outside. Those values both in summer and in winter as relative humidities in door was lower than optimum for growing pigs, the additional humidifier might be helpful to increase the relative humidity in indoor. 3. The horizontal distribution of the indoor temperature was found to be uniform in the variation range of 1$^{\circ}C$. 4. The vertical distribution of the indoor temperature was not found to be uniform; the temperature of upper part was higher than that of slot part. 5. Average values of indoor temperature became lower by 3$^{\circ}C$ by mist cooling. But the variation of temperature was found to be larger; The middle part of the room was cooled down, but the corner part of the room was not affected by misting due to uneven nozzle configuration.

• Smart Structures and Systems
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• 제20권3호
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• pp.351-368
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• 2017

To peruse the free vibration of curved functionally graded piezoelectric (FGP) nanosize beam in thermal environment, nonlocal elasticity theory is applied for modeling the nano scale effect. The governing equations are obtained via the energy method. Analytically Navier solution is employed to solve the governing equations for simply supported boundary conditions. Solving these equations enables us to estimate the natural frequency for curved FGP nanobeam under the effect of a uniform temperature change and external electric voltage. The results determined are verified by comparing the results by available ones in literature. The effects of various parameters such as nonlocality, uniform temperature changes, external electric voltage, gradient index, opening angle and aspect ratio of curved FGP nanobeam on the natural frequency are successfully discussed. The results revealed that the natural frequency of curved FGP nanobeam is significantly influenced by these effects.

• 설비공학논문집
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• 제3권2호
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• pp.114-122
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• 1991

A thermal analysis method taking into account energy balance in each elements of heat exchanger was introduced. This method has a merit in predicting the temperature field over the heat exchanger in detail. To verify this method, the results were compared with the published ones. The thermal analysis of the radiator in vehicles was also conducted and the results were compared with experimental ones. It is concluded that this method can be used in thermal analysis with relatively small error. When the velocity profile of inlet air is not uniform, the outlet temperature of cooling water is higher than that of uniform velocity profile.