• Korean Journal of Human Ecology
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• v.8 no.1
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• pp.151-163
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• 1999

The purpose of this study was to investigate the thermal resistance and the liquid/vapor water transfer characteristics of four waterproof and water vapor permeable coated fabrics with the ground fabric called nylon taffeta. In order to establish the experimental environment, outdoor temperature and humidity in Taegu during the last three years were examined and the experiment was performed at (1) $15^{\circ}C$, 50% R.H., (2) $20^{\circ}C$, 60% R.H., (3) $25^{\circ}C$, 65% R.H., which were the average standards in spring and fall. The test results were as follows ; 1. Among physical parameters, the thinner the thickness was, the higher the water vapor permeability was. But the porosity in thickness was not proportional to water vapor permeability linearly. 2. The thicker the thickness of specimens was and the smaller the bulk density and porosity were, the higher the thermal resistance. And the results also shown that the larger the temperature difference between the environmental temperature and the hot plate was, the more the difference of CLO values was apparent. 3. Since the contact angle of all specimens are above $90^{\circ}$, the all specimens have a good performance in waterproof. The more the specimens surface were rough, the higher the thermal resistance was. 4. According to the result of performing moisture transfer test using the simulating body skin-clothing-environment system, the humidity sensor placed in between the fabric and the environment detected the full saturation in 10 minutes after the experiment had began at $15^{\circ}C$, 50% R.H. and in 15 minutes after the experiment both at $20^{\circ}C$, 60% R.H. and at $25^{\circ}C$, 65% R.H. 5. ${\Delta}$ values of the humidity sensors placed in between the human body and the fabric and in between the fabric and the environment fluctuated repeatedly within the range of $20{\sim}40%$ at $20^{\circ}C$, 60% R.H., and $15{\sim}30%$ at $25^{\circ}C$, 65% R.H.

• Design & Manufacturing
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• v.17 no.2
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• pp.9-14
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• 2023

In this study, an experiment was conducted to confirm the applicability of the external shape control of the ultrasonic knife to the CFRTP material, which is the base material of thermoplastic. TC910 based on polyamide6 (PA6) was used as the material. The slope 와 and tool transfer speed of the material and tool were selected as process factors for processing, and the following results were obtained. Under all cutting conditions using an ultrasonic knife, friction heat caused by high-frequency vibration was issued at 150℃ at the contact part between the material and the knife during cutting. As a result of the cutting force analysis, the faster the transfer speed, the higher the cutting force as the angle of entry of the blade increased, and the size of the cutting force changed during cutting. As for the size of the burr in accordance with the transfer speed condition, the smallest burr occurred at 150mm/min in the side part, and the smallest burr occurred at 150mm/min and 200mm/min in the case of the outlet burr. The size of the burr according to the entry angle tended to decrease as the tool entry angle increased, and the side part tended to increase as the tool entry angle increased. As a result of the cutting surface analysis, it was confirmed that the base material was eluted under all conditions, and the faster the transfer speed, the lower the elution phenomenon of the base material. Based on the above results, cutting the CFRTP material with an ultrasonic knife is possible, but the effect on heat generation caused by friction needs to be minimized, and further research needs to be conducted on this.

• Journal of Energy Engineering
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• v.21 no.2
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• pp.138-143
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• 2012

The present study has been carried out to elucidate the unsteady temperature characteristics of a refrigerator near gasket region by measuring time dependent temperature measurements. From the measured values of the time dependent temperature inside and outside region of a refrigerator, one could see that the temperature varies periodically with time from the effect of refrigerator operation. The measured mean temperatures at the wall had great different value from the previous other research results conducted by numeric ofheat transfer using improperfheat transfer boundary condition. The present study could give the experiment ofdata for the properfnumeric ofheat transfer an oysis and suggest more accuratefheat transfer boundary conditions for the inside and outside of a refrigerator.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.829-836
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• 1998

Immunogenicity of Escherichia coli pilus and LT were evaluated in 20-week-old hens. The antigens were consisted of K88, K99, 987p pilus and heat labile toxin purified from enterotoxigenic Escherichia coli. The durations of antibody titers in sera and egg yolk were investigated by an enzyme-linked immunosorbent assay(ELISA). After first inoculation, antibody titers in sera reached at peak 2 weeks postinoculation. However, peak antibody titers in egg yolk were detected 4 weeks postinoculation, indicating that transfer of immunoglobulin from serum to egg yolk took about two weeks period. Although there were slight reduction in titers, the specific antibodies in egg yolk lasted up to 3 months. Immune responses against monovalent and combined antigens were showed as almost same patterns. The transfer rate of antibodies from serum to egg yolk didn't show any significant differences among three pilus antigens in this study. Considering the concentrations of antigens in each inoculated group, multivalent antigens containing heat labile toxin of E coli were found to be more immunogenic than monovalent antigen in producing specific antibodies. From this experiment, it was demonstrated that multivalent antigens containing three pilus and heat labile toxin could be a promising candidate for the production of egg yolk antibodies for prophylactic use in preventing swine colibacillosis in future.

• Journal of the Korean Society of Safety
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• v.27 no.4
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• pp.7-12
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• 2012

In this study, the solidification characteristics inside the AC7A casting material was analyzed using the numerical analysis method and was verified using the experimental method by the pre-heated temperature conditions of metal casting device. For the numerical analysis, "COMSOL Multiphysics", the commercial code based on the finite element analysis(FEA), was used in order to predict the thermal deformation of the AC7A casting material including temperature, displacement and stress distribution. Also, in order to verify the results calculated by the numerical analysis, the experiment for temperature measurement inside the AC7A casting material was performed using the K-type thermocouple under the same condition of numerical analysis method. In the numerical results, thermal deformation inside AC7A casting material was well-suited for manufacturing products when the pre-heated temperatures of the metal casting device was $250^{\circ}C$. When the results of the temperature distribution were experimentally measured and were compared with those of the numerical result, it appeared that there was some temperature difference because of the latent heat by phase change heat transfer. However, the result of cooling temperature and patterns were almost similar except for the latent heat interval. The solidification characteristics was closely related to the temperature difference between the surface and inside of the casting.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.2
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• pp.130-137
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• 2012

In this paper, a post-analysis of cooling system for infrared(IR) window was performed based on heating experiment of IR window system. We applied the same experimental conditions to analysis, and then validated the analysis technique by comparing numerical and experimental results. For an analysis software, we used a professional heat/fluid analysis program and the numerical and experimental results were in fairly good agreement. We investigated the effect of thermal transfer between the frame and IR window and also a cooling efficiency between fluid and structure in order to determine the proper parameters for the analysis. In this study, 100 % thermal transfer between the frame and IR window and 30 % cooling efficiency between fluid and structure have been proposed, which can be used in the future conceptual design and analysis of similar IR windows.

• Journal of the Korean Society of Clothing and Textiles
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• v.43 no.4
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• pp.592-604
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• 2019

This study examines the stealth function of sputtered fabric with an infrared thermal imaging camera in terms of the thermal and infrared (IR) transmittance characteristics. Various base fabrics were selected, infrared imaging was performed, and infrared transmittance was measured. By infrared camera experiment it was found that the sample was concealed because it had a similar color to the surroundings when the aluminum layer was directed toward the outside. In addition, a comparison of the infrared thermographic image of the untreated sample and the sputtered sample in the laboratory showed that the difference in ${\Delta}E$ value ranged from 31 to 90.4 and demonstrated effective concealment. However, concealment was not observed in the case of the 3-layer (Nylon-Al-Nylon) model when a sputtered aluminum layer existed between two nylon layers. The direction of the sputtering layer did not affect the infrared transmittance in the infrared transmittance experiment. Therefore, it seems better to interpret the concealing effect in the infrared thermographic images by using thermal transfer theory rather than infrared transmittance theory. We believe that the results of this study will be applicable to developing high performance smart clothing and military uniforms.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.6
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• pp.629-637
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• 2021

For the stabilization of laser output power and wavelength of the high power fiber laser, the cooling plate must be properly taken into account. In this study, three analyzing methods which are heat transfer theory, CFD and experiment are used to analyze cooling plate performance by measuring pump Laser Diode(LD) temperature. Under limited operating conditions of a cooling plate, the internal flow of cooling plate is transitional flow so that the internal flow is assumed to be laminar and turbulence flow and conducted theoretical calculation. Through CFD, temperature of pump LD and characteristics of the internal flow were analyzed. By the experiment, temperature of pump LD was measured in real conditions and the performance of the cooling plate was verified. The results of this study indicate that three analyzing methods are practically useful to design the cooling plate for the high power fiber laser or similar things.

• Journal of the Korean Society of Combustion
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• v.19 no.4
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• pp.35-41
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• 2014

The experiment was conducted to measure temperature and pressure around operating portable butane gas ranges with oversized cookwares. In this experiment, portable butane gas range with different safety equipment and two kinds of oversized cookware, each of which is made of aluminum alloy and rock, was used. As a result, temperature of the bottom of the butane and the pressure of butane barrel tend to aligned with each other. Through this result, it is reasonable that a safety criteria can be decided based on the temperature of the bottom of butane. Especially, portable butane gas ranges are safely conducted under the condition of the temperature is under 50 degree and pressure is under 500 kPa, respectively, at the bottom of the butane barrel.

• Journal of Energy Engineering
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• v.23 no.4
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• pp.112-122
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• 2014

A main steam line break (MSLB) test at the ATLAS facility was simulated using the best-estimate thermal-hydraulic system code, MARS-KS. This has been performed as an activity at the third domestic standard problem for code benchmark (DSP-03) that has been organized by Korea Atomic Energy Research Institute (KAERI). The results of the MSLB experiment and the MARS input data prepared for the previous DSP-02 using the ATLAS facility were provided to participants. The preliminary MSLB simulation using the base input data, however, showed unphysical results in the primary-to-secondary heat transfer. To resolve the problems, some improvements were implemented in the MARS input modelling. These include the use of fine meshes for the bottom region of the steam generator secondary side and proper thermal-hydraulics calculation options. Other input model improvements in the heat loss and the flow restrictor models were also made and the results were investigated in detail. From the results of simulations, the limitations and further improvement areas of the MARS code were identified.