• 대한의용생체공학회:의공학회지
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• 제38권5호
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• pp.232-236
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• 2017

In this study, We investigated the effect of foot cooling on the reduction of body temperature after hard exercise at the high temperature of $40^{\circ}C$. We performed a total of 30 subjects, and the subjects performed treadmill exercise for 30 minutes. We produced the cooling device to cool the foot using Peltier module. After the end of the exercise, We performed normal recovery method and cooling recovery method(one foot, both feet) for 1 hour on the same indoor environmental conditions and confirmed the change of body temperature of subjects. The results of deep body temperature measurement showed average $38.78{\pm}0.22^{\circ}C$ to $38.54{\pm}0.15^{\circ}C$ when the normal recovery method was performed. Cooling recovery method on one foot showed average $38.69{\pm}0.14^{\circ}C$ to average $38.06{\pm}0.17^{\circ}C$ and Cooling recovery method on both feet showed average $38.69{\pm}0.15^{\circ}C$ to average $37.84{\pm}0.21^{\circ}C$. There was a significant difference between the normal recovery method and the one foot cooling recovery method(p < .05), there was a significant difference between the normal recovery method and the both feet cooling recovery method(p < .05) and there was a significant difference between the one foot cooling recovery method and the both feet cooling recovery method(p < .05). Body temperature showed the lowest decrease rate when the normal recovery method was performed, and body temperature showed the highest decrease rate when the both feet cooling recovery method was performed. Therefore, recovery of cooling on the foot after hard exercise have decreased body temperature, delay fatigue in the body, and will be contributed to improvement of athlete performance.

• 대한치과기공학회지
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• 제23권2호
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• pp.203-210
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• 2002

This test is to conduct applied research the reaction area of the Ti-cast metal body which is made use of Dental Phosphate-silica alumina bonded investment material selling at a market, and the cooling method is how to effect on the acicular. The experimentation is as followings, 1. Experimental specimens After invest with Dental Phosphate-silica alumina bonded investment material, the $10{\times}10{\times}1.0mm^3$ wax pattern was casted by Dental high vacuum argon centrifugal casting machine. 2. Test We can analyze SEM/EDS, XRD utilize the fractography(an optical microscope). 3. Conclusion The pure cast metal body constituted of reaction products layer, stability layer and contamination layer. This pure cast have no connection with the cooling condition. The pure Titanium shows difference in a component distribution according to the cooling condition. Through this experimentation we can establish that acicular in the pure Ti-cast metal is consist of Hexagonal structure a=2.9505$\AA$, c=4.6826$\AA$.

• 대한의용생체공학회:의공학회지
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• 제38권4호
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• pp.163-167
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• 2017

The purpose of this study is to perform integrated body temperature cooling of the arteriovenous anastomosis site. In the arteriovenous anastomosis site, heart cooling was performed using the palm of the hand, Cooling was achieved by using Peltier and copper plates to cool the palm of the hand with the heat transferred. The control range of the conducted heat is adjustable from 25 degrees to 30 degrees. The experimental environment was to place the treadmill in the house, The temperature in the house was set at 40 degrees and the experimenter treadmill at a speed of 5 Km. The subjects were exercised until the body temperature reached about $39^{\circ}C$. As a method to lower the body temperature after the experiment, the data of the body temperature was obtained by the general rest, onehand cooling, two-hand cooling. Experiment result better than normal rest when Two hands cooling and an average decrease of 0.66 degrees. if you develop a cooling glove with Peltier, it will be an epoch-making athletic assistant to achieve thermal fatigue.

• Design & Manufacturing
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• 제16권2호
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• pp.46-52
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• 2022

As the consumer market in the eco-friendly vehicle industry grows, the demand for water pump in a electric car parts market. This study intend to propose a mathematical model that can verify the effect of improving thermal properties when a non-conductive cooling filler liquid is introduced into an electric vehicle water pump. Also, the pros and cons of the immersion cooling method and future development way were suggested by analyzing the cooling characteristics using on the derived analysis solution. Thermal characteristics analysis of electric water pump applied with non-conductive filler liquid was carried out, and the diffusion boundary condition in the motor body and the boundary condition the inside pump were expressed as a geometric model. As a result of analyzing the temperature change for the heat source of the natural convection method and the heat conduction method, the natural convection method has difficulty in dissipating heat because no decrease in temperature due to heat release was found even after 300 sec. Also, it can be seen that the heat dissipation effect was obtained even though the non-conductive filling liquid was applied at the 120 sec and 180 sec in the heat conduction method. It has proposed to minimize thermal embrittlement and lower motor torque by injecting a non-conductive filler liquid into the motor body and designing a partition wall thickness of 2.5 mm or less.

• Human Ecology Research
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• 제56권5호
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• pp.473-491
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• 2018

This study identifies Japanese study content on heat stroke prevention measures using clothes, provides basic data for quantitative wearing assessment studies, presents a developmental direction for those, and helps invigorate further research. Studies were collected concerning clothing-based heat stroke measures in order to analyze the following factors: current status of heat stroke by industry and working environment, heat stroke and body cooling method, clothing microclimate and air circulation in a hot environment, hot environments and wearable sensors, and heat stress reduction and skin exposure. The current WBGT standard does not consider the diversity of wearing clothes according to the working environment. Therefore, it is preferable to add a correction value in consideration of design, materials, and ventilation to prevent heat strokes. For the heat stroke and body cooling method, wearing water-perfused clothing is effective to reduce heat stress and maintain exercise ability. Changing the material and design of clothing or wearing air-conditioned clothing can improve ventilation and the clothing microclimate. However, further evaluation is needed on the effectiveness of air-conditioned clothing as a heat stroke prevention product. The measurement method using a wearable sensor can provide real-time data on the body response due to working in a hot environment. Therefore, it is an effective alarm for heat stroke. Skin exposure area and heat dissipation efficiency should be considered to prevent heat stroke. Reducing the covering area by exposing the head, neck, and limbs, and wearing breathable material can prevent heat stroke from increased body temperature.

• 한국전기전자재료학회논문지
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• 제17권3호
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• pp.348-352
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• 2004

The mold transformers have been widely used in underground substations in large building and have some advantages in comparison to oil-transformer, that is low fire risk, excellent environmental compatibility, compact size and high reliability. In addition, the application of mold transformer for outdoor is possible due to development of epoxy resin. The mold transformer generally has cooling duct between low voltage coil and high voltage coil. A mold transformer made by one body molding method has been developed for small size and ow loss, but it needs some cooling method because heat radiation between each winding is difficult. The life of transformer is significantly dependent on the thermal behavior in windings. Many transformer designers have calculated temperature distribution and hot spot point by finite element method(FEM) to analyze winding temperature rise. In this paper, The thermal analysis of pole mount mold transformer with one body molding by duct condition is investigated and the test result of temperature rise is compared with simulation data.

• 한국유체기계학회 논문집
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• 제14권3호
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• pp.33-38
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• 2011

Medicated water electrolysis apparatus, which electrolyzes water into acidic water and alkaline water, was in the spotlight as becoming known the effect of alkaline water. It is known as good for health as removing active oxygen in the human's body and promoting digestion. But, the customers could not get that desired water temperature because these apparatuses are directly connected with a water pipe. So, the cooling system was developed for controlling the temperature of the alkaline water. One of the typical way is to store water in water tank and control the temperature. But, in this way, storing water can be polluted impurities coming from outside. For protecting this pollution, the cooling system based on indirect heat exchange method through phase change between water and ice was developed. In this study, we have calculated efficiency of the cooling system with phase change by experiment and commercial CFD(Computational Fluid Dynamics) code, ANSYS CFX. To consider the effect of latent heat that is generated by melting ice, we have simulated two phase numerical analyses used enthalpy method and found the temperature, velocity, and ice mass distribution for calculating the efficiency of cooling. From the results of numerical analysis, we have obtained the relationship between the cooling efficiency and each design factor.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.1135-1138
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• 2003

The transformer is major equipment in power receiving and substation facilities. Necessary conditions required for the transformer are compactness, lightness, high reliability, economic advantages, and easy maintenance. The pole-mount transformer installed in distribution system is acting direct role in supply of electric power and it is electric power device should drive for long term. Most of modem transformer are oil-filled transformer and accident is happening considerable. The mold transformers have been widely used in underground substations in large building and have some advantages in comparison to oil-transformer, that is low fire risk, excellent environmental compatibility, compact size and high reliability. In addition, the application of mold transformer for outdoor is possible due to development of epoxy resin. The mold transformer generally has cooling duct between low voltage coil and high voltage coil. A mold transformer made by one body molding method has been developed for small size and low loss. One body molding transformer needs some cooling method because heat radiation between each winding is difficult. In this paper, The thermal analysis of pole mount mold transformer with one body molding by duct condition is investigated and the test result of temperature rise is compared with simulation data.

• 한국기계가공학회지
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• 제21권5호
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• pp.98-104
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• 2022

When processing parts, the cutting oil can improve the cooling performance of the workpiece and tool to increase the precision of the workpiece or extend the life of the tool and facilitate chip extraction. Since such cutting oil has a harmful effect on the environment and the human body due to additives such as sulfur, research on a minimum lubrication supply method using an eco-friendly oil is recently underway. The minimum lubrication supply method minimizes the amount of cutting oil used during processing and processes it, which can reduce the amount of cutting oil used, but has a problem in that cooling performance efficiency is poor. Therefore, this study conducted a study on mist cooling of lubricants to reduce the amount of cutting oil used and maximize the cooling effect of processing heat generated during tapping processing. Spray pressure, processing speed, direction, and lubricant spray amount, which are considered to have an effect on cooling performance, were set as process conditions, and the effect on temperature was analyzed by performing an experiment using the box benquin method among experiments were analyzed. Through the experimental analysis results, the optimal conditions for mist and processing that maximize the cooling effect were derived, and the validity of the results derived through additional experiments was verified. In the case of processing by applying the mist lubrication method verified through this study, it is considered that high-precision processing is possible by improving the cooling effect.

• 한국전기전자재료학회논문지
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• 제19권12호
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• pp.1154-1159
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• 2006

The mold transformers have been widely used in underground substations of large building and have some advantages when compared with oil-transformer. Those advantages are low fire risk, environmental compatibility, compact size and high reliability. The mold transformer is generally known to have cooling duct between low voltage and high voltage coil. To achieve better compact structure and low loss, mold transformers made by one body molding method has been developed. Nevertheless, such kinds of transformer need better cooling method because heat radiation between each winding is still of problem. The life of transformer is significantly dependent on the thermal behavior in windings. Many designers have calculated temperature distribution in transformers and hot spot point by finite element method(FEM) to analyze winding temperature rise. In this paper, the temperature distribution analysis of 100 kVA pole mold transformer for power distribution were investigated by FEM program and the thermal analysis results were compared with temperature rise test.