• The Korean Journal of Community Living Science
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• v.26 no.4
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• pp.775-783
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• 2015

This study investigates gender differences in cold perceptions and wearing behaviors for cold adaptation. A questionnaire composed of items on cold perceptions, intentions toward wearing additional clothing, and clothing for outdoor environments, among others, was used. Each item in the survey targeted 260 male (MS) and female (FS) college students evaluated using a five-point Likert-type scale. Data were statistically analyzed using the independent sample t-test and correlations. Main results can be summarized as follows: MS subjects showed lower dependence on the thermal insulation of clothing because they felt less cold and had the better ability to cope with cold. MS subjects had higher dependence on underwear during cold seasons, and FS subjects tended to wear heavier clothing to compensate for their cold feet with insufficient insulation. In addition, it was preferable to estimate thermal effects of actual wear by taking into account gender differences in the physique. The study is limited in that the room temperature and the actual amount of clothing were not measured, which offers an avenue for future research.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.1
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• pp.46-53
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• 2013

Impedance spectroscopy is a non-destructive evaluation (NDE) method first proposed and developed for evaluating TGO layers with compressive stress inside thermally degraded plasma-sprayed thermal barrier coatings (PS TBCs). A bode plot (phase angle (h) vs. frequency (f)) was used to investigate the TGO layer on electrical responses. In our experimental study, the phase angle of Bode plots is sensitive for detecting TGO layers while applying compressive stress on thermal barrier coatings. It is difficult to detect TGO layers in samples isothermally aged for 100 hrs and 200 hrs without compressive stress, and substantial change of phase was observed these samples with compressive stress. Also, the frequency shift of the phase angle and change of the phase angle are observed in samples isothermally aged for more than 400 hrs.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2005.11a
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• pp.301-306
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• 2005

The purpose of this study is to make clear the cross-ventilation effect by floor plan type in apartment house during summer. The questionnaire survey was carried out during the 26$^{th}$ of August ${\sim}$ the 4$^{th}$ of September 2004. The respondents were 174 residents living in two subject apartment estates. One subject estate (we call A estate) was consisted apartment houses having cross-ventilation floor plan. The other subject estate (we cail B estate) was constructed apartment houses having ordinary floor plan. The field measurements of indoor thermal elements reflecting natural cooling effect by cross-ventilation were carried out at A house in A estate and at B house in B estate. The measurements in two subject houses were taken on simultaneously the 27$^{th}$ of August. The residents living in A apartment estate planed cross-ventilation type show positive responses on thermal sensation and airflow sensation. The averages indoor temperature and air velocity in the A house were 0.9 $^{\circ}$C lower and 0.29 m/s higher than the B house. Therefore, it was found that indoor thermal environment during summer in the house having cross-ventilation floor plan maintained more comfortable than the house having ordinary floor plan by natural cooling effect of cross-ventilation.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.262-268
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• 2022

This paper introduces a novel concept of the pulsed neutron facility (PNF) for maximizing the production of the thermal neutrons and its application to medical use based on prompt gamma neutron activation analysis (PGNAA) using Monte Carlo simulations. The PNF consists of a compact D-T neutron generator, a graphite pile, and a detection system using Cadmium telluride (CdTe) detector arrays. The configuration of fuel pins in the graphite monolith and the design and materials for the moderating layer were studied to optimize the thermal neutron yields. Biological samples - normal and cancerous breast tissues - including chlorine, a trace element, were used to investigate the sensitivity of the characteristic γ-rays by neutron-trace material interactions and the detector responses of multiple particles. Around 90 % of neutrons emitted from a deuterium-tritium (D-T) neutron generator thermalized as they passed through the graphite stockpile. The thermal neutrons captured the chlorines in the samples, then the characteristic γ-rays with specific energy levels of 6.12, 7.80 and 8.58 MeV were emitted. Since the concentration of chlorine in the cancerous tissue is twice that in the normal tissue, the count ratio of the characteristic g-rays of the cancerous tissue over the normal tissue is approximately 2.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.14 no.1
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• pp.21-30
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• 1985

One of the problems with the Boiling Water Reactor involves the flow and thermal mixings in the suppression water pool high pressure steam discharge into the pool in case of emergency core relief. Varioos heat sensitive devices and pumps for the reactor core cooling are installed in the middle of the suppression pool. Especially the pumps utilize pool water in order to cool the reactor core in emergency cases. In this case, the water temperature for the reactor cool ins should be below a certain temperature specified by the reactor design. In the present investigation, in other to determine the optimum locations of these pumping devices, numerical solutions have been obtained for the model to determine the f low mixing characteristics. Experimental investigations have also been carried out for the flow mixing and for the thermal mixing in the pool during the discharge. Considering that the discharge steam through the Quenching Device becomes hot water immediately in the water pool, the steam- equivalent hot water has been utilized. Examining these characteristices, it becomes possible to deform me the best locations for RCIC, LPCI , HPCI pumps in the suppression water pool for the emermency reactor core cooling.

• Journal of the Ergonomics Society of Korea
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• v.17 no.3
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• pp.41-59
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• 1998

Thermal comfort aspect of a locally-cooled target space in warm and humid environments(typically in the rainy summer season) was studied in view of PPD index. First. theoretical analyses were conducted to examine the effect of the governing parameters(such as air temperature, relative humidity and air velocity, etc.) using a computer model. Secondly, experimental investigations were also performed in a climatic room designed to simulate corresponding thermal conditions of outdoor environments. During the tests, temporal variation of PPD was recorded as functions of climatic variables(outdoor and indoor temperatures, relative humidity and air velocity) for the given human factors(metabolic heat generation and clothing). From both theoretical and experimental investigations, air temperature and air velocity were found to be the most dominant parameters affecting PPD of the target space. Results were summarized as: 1. Relative humidity of the locally-cooled target space tends to approach that of outdoor's as the space is subjected to an ON-OFF mode of cooling, since moisture potential of the two rooms reaches an equalized state as a result of moisture diffusion. 2. It was recognized that changes in relative humidity did not show any significance in view of thermal comfort as was reported in the previous studies, while variations of both temperature and air velocity caused relatively large changes in the degree of thermal comfort. 3. In-door environment should be evaluated in terms of PPD instead of relative humidity commonly recognized as an important climatic variable particularly in warm and humid environments.

• The Korean Journal of Community Living Science
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• v.17 no.4
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• pp.49-56
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• 2006

The purpose of this study was to evaluate the thermal and subjective comfort of various pesticide-proof clothes made from different material. Seven male adults took part in the study, conducted in a climate-chamber controlled with an ambient temperature of $30^{\circ}C$ and a relative humidity of 60%RH. The thermal and subjective responses of subjects wearing pesticide-proof clothing made of Goretex(coating treatment), polyester (water-repellent treatment), non-woven(coating) and nylon(coating) were measured. The main results were summarized as follows: (1) Change of rectal temperature and clothing microclimate were inhibited more effectively in pesticide-proof clothing made of Goretex, polyester and non-woven than nylon materials. (2) Mean skin temperature at the end of the experiment was significantly higher in subjects who wore nylon than non-woven and Goretex, and was lowest in those with pesticide-proof clothing made of polyester. (3) Change of heart rate was significantly lower in subjects with Goretex and polyester clothiing than those with non-woven, and in those with nylon, it was highest. (4) Subjective comfort was greater in subjects with Goretex, polyester and nonwoven clothing than nylon, except for thermal sensation. Thermal sensation was greater in order of polyester, Goretex, non-woven and nylon. Thus, it was concluded that pesticide-proof clothing made of Goretex, polyester and non-woven material could reduce thermal stress during the spraying of pesticides in summer.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.10
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• pp.699-705
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• 2001

Six types of planar thermal converters from TC 1 to TC 6 were designed and fabricated for the purpose of being used as practical standards to alternating current. The respective voltage responses in air and in a vacuum of TC 6, which has the smallest thermal loss, were about 4.03mV/mW and about 6.38 mV/mW. Thermal time constant of TC 6, which has also the smallest heater thermal inertia, was about 8 ms. The respective variations of AC-DC voltage and current transfer errors from sample to sample, which were measured by FRDC(fast reversed DC) method, were about $\pm$0.41 ~$\pm$0.85 ppm and about $\pm$0.15~$\pm$1.16 ppm in the frequent range of 40 Hz~10 KHz with appling 1 V and 5 mA rms sine waves to the converters. All converters investigated exhibited sufficiently low AC-DC transfer errors to be used as practical standards.

• Journal of Industrial Convergence
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• v.22 no.10
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• pp.53-63
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• 2024

This study evaluates the potential effects of the Ceragem spinal thermal massage device on sleep quality and analyzes how its thermal and mechanical massage stimuli influence physiological responses. Clinical studies and case reports suggest that the device's thermal stimulation may help regulate the autonomic nervous system, reduce stress and pain, and potentially improve sleep quality. Additionally, mechanical massage may induce muscle relaxation and stabilize the nervous system, contributing to overall body relaxation. Electromyography (EMG) results indicate that mechanical stimulation may reduce muscle tension and help recalibrate autonomic balance. In conclusion, the Ceragem device shows promise as a non-pharmacological tool for improving sleep quality, though further systematic and rigorous research is needed.

• Journal of Microbiology and Biotechnology
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• v.30 no.8
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• pp.1207-1213
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• 2020

Aflatoxin B1 (AFB1) is a mycotoxin produced by Aspergillus flavus (A. flavus). AFB1 is reported to have high thermal stability and is not decomposed by heat treatment during food processing. Therefore, in this study, knowing that AFB1 is metabolized by cytochrome P450 (CYP), our aim was to develop a method to detoxify A. flavus-contaminated maize, under normal temperature and pressure, using Escherichia coli expressing human CYP3A4. First, the metabolic activity of AFB1 by recombinant human CYP3A4 was evaluated. As a result, we confirmed that recombinant human CYP3A4 metabolizes 98% of AFB1. Next, we found that aflatoxin Q1, a metabolite of AFB1 was no longer mutagenic. Furthermore, we revealed that about 50% of the AFB1 metabolic activity can be maintained for 3 months when E. coli expressing human CYP3A4 is freeze-dried in the presence of trehalose. Finally, we found that 80% of AFB1 in A. flavus-contaminated maize was metabolized by E. coli expressing human CYP3A4 in the presence of surfactant triton X-405 at a final concentration of 10% (v/v). From these results, we conclude that AFB1 in A. flavus-contaminated maize can be detoxified under normal temperature and pressure by using E. coli expressing human CYP3A4.