• Title/Summary/Keyword: heat-cold test

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A Comparative Study of Response of KS-15 Questionnaire between Migrant Vietnam and Daejeon Women (대전시 여성과 베트남 이주여성의 단축형 사상체질진단 설문지(KS-15) 응답 비교)

  • Baek, Younghwa;Kim, Hoseok;Jang, Eunsu
    • Journal of Sasang Constitutional Medicine
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    • v.33 no.2
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    • pp.25-36
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    • 2021
  • Objectives The aim of this study was to reveal the difference of body shape, personality, physiological characteristics between migrant Vietnam and Daejeon women using propensity matching. Methods The number of 274 Vietnamese migrant women and Daejeon city women participate in this study. We surveyed Sasang Constitution (SC) expressive factor, such Body Mass Index (BMI) using Korea Sasang Constitutional Diagnostic Questionnaire (KS-15). A Chi-square test and a T-test were used. Significant p was .05. Results The height, weight and BMI of Daejeon women was bigger than those of Vietnam(p<.001). There was significant difference in personality characteristics in 'broad mind-narrow mind'(p<.001), 'Active-Passive'(p<.001), 'Masculine-Feminine'(p=.002). There was significant differentce in physio-pathological symptom in 'digestion'(p<.001), 'urine time'(p<.001), 'feeling cold/heat'(p=.006). There was significant differentce in distribution of SC between Vietnam and Daejeon women(p=.025). Conclusions This study reveals that there is differentce in body shape, personality, physiological characteristics between Vietnam and Daejeon women. These factors might influence on SC distribution between Vietnam and Dajeon women

Effect of Post Heat Treatment Temperature on Interface Diffusion Layer and Bonding Force in Roll Cladded Ti/Mild steel/Ti Material (압연 클래드된 Ti/Mild steel/Ti 재의 계면확산층과 접합력에 미치는 후열처리온도의 영향)

  • Lee, Sangmok;Kim, Su-Min;We, Se-Na;Bae, Dong-Hyun;Lee, Geun-An;Lee, Jong-Sup;Kim, Yong-Bae;Bae, Dong-Su
    • Korean Journal of Metals and Materials
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    • v.50 no.4
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    • pp.316-323
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    • 2012
  • The aim of this study is to investigate the effect of post heat treatment on bonding properties of roll cladded Ti/MS/Ti materials. First grade Ti sheets and SPCC mild steel sheets were prepared and then Ti/MS/Ti clad materials were fabricated by a cold rolling and post heat treatment process. Microstructure and point analysis of the Ti/MS interfaces were performed using the SEM and EDX Analyser. Diffusion bonding was observed at the interfaces of Ti/MS. The thickness of the diffusion layer increased with post heat treatment temperature and the diffusion layer was verified as having $({\epsilon}+{\zeta})+({\zeta}+{\beta}-Ti)$ intermetallic compounds at $700^{\circ}C$ and an $({\zeta}+{\beta}-Ti)$ intermetallic compound at $800^{\circ}C$, respectively. The micro Knoop hardness of mild steel decreased with post heat treatment temperature; however, those of Ti decreased at a range of $500{\sim}600^{\circ}C$ and showed a uniform value until $800^{\circ}C$ and then increased rapidly up to $900^{\circ}C$. The micro Knoop hardness value of the diffusion layer increased up to $700^{\circ}C$ and then saturated with post heat treatment. A T-type peel test was used to estimate the bonding forces of Ti/Mild steel interfaces. The bonding forces decreased up to $800^{\circ}C$ and then increased slightly with post heat treatment. The optimized temperature ranges for post heat treatment were $500{\sim}600^{\circ}C$ to obtain the proper formability for an additional plastic deformation process.

Overall Performance characteristic for 300MW Taean IGCC Plant (300MW 태안 IGCC 플랜트 종합성능 특성)

  • Kim, Hakyong;Kim, Jaehwan
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.129.2-129.2
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    • 2010
  • As a part of the government renewable energy policy, KOWEPO is constructing 300MW IGCC plant in Taean. IGCC plant consists of gasification block, air separation unit and power block, which performance test is separately conducted. Overall performance test for IGCC plant is peformed to comply with ASME PTC 46. Major factors affected on the overall efficiency for IGCC plant are external conditions, each block performance(gasification, ASU, power block), water/steam integration and air integration. Performance parameters of IGCC plant are cold gas efficiency, oxygen consumption, sensible heat recovery of syngas cooler for gasification block and purity of oxygen, flow amount of oxygen and nitrogen, power consumption for air separation unit and steam/water integration among the each block. The gas turbine capacity applied to the IGCC plant is 20 percent higher than NGCC gas turbine due to the low caloric heating value of syngas, therefor it is possible to utilize air integration between gas turbine and air separation unit to improve overall efficiency of the IGCC plant and there is a little impact on the ambient condition. It is very important to optimize the air integration design with consideration to the optimized integration ratio and the reliable operation. Optimized steam/water integration between power block and gasification block can improve overall efficiency of IGCC plant where the optimized heat recovery from gasification block should be considered. Finally, It is possibile to achieve the target efficiency above 42 percent(HHV, Net) for 300MW Taean IGCC plant by optimized design and integration.

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Effects of Humidity and Velocity on Frost Distribution Characteristics of Humid Air Flow on Cold Surfaces (차가운 표면위에서의 습공기 유동의 습도 및 속도가 착상분포 특성에 미치는 영향)

  • Kwon Jeong-Tae;Rew Keun-Ho;Lim Hyo-Jae;Han Ji-Won;Kwon Young Chul
    • Journal of Energy Engineering
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    • v.14 no.4 s.44
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    • pp.213-218
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    • 2005
  • In order to understand the heat and mass transfer characteristics of humid airflow in frosting conditions, a flat plate of aluminum with cooling modules located in the central part of the plate was used. A microscope system (resolution of 0.05 mm) was used for the measurement of local thickness of frost at seven points along the plate in the flow direction. For the total mass of frost at each test operation, an electronic balance (resolution of 1 mg) was used. The local frost thickness distributions far various test conditions were presented along with the frost mass data measured at the given operating times. The effect of humidity and velocity of humid air on frosting were analyzed.

Thermal Comfort of the Sports/Leisure Clothing with the Heat Storage/Reflection Function - Wearing Evaluation under the Condition of 0x00B1;1℃ and 50±5% RH - (축열/체열반사기능을 가진 스포츠 레저복의 온열쾌적성 - 0±1℃, 50±5% RH 환경에서의 착의평가 -)

  • Kim, Tae-Gyou;Song, Min Kyu;Lee, Chang Min;Kwon, Oh Kyung
    • Fashion & Textile Research Journal
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    • v.20 no.4
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    • pp.474-481
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    • 2018
  • For this study, we developed clothing in which textile materials that were excellent weather control function for the cold environment and we performed the human subject test with developed clothing to determine the thermal comfort. We used 2 clothing samples developed (A and B, hollow yarn+moisture absorption/quick drying yarn, 3 layers, high stretchable, heat reflection film and lamination treated) and a control sample (Ctrl.) for the human subject test and 8 adult males were used as a human subjects and environmental conditions of chamber were $0{\pm}1^{\circ}C$. $50{\pm}5%RH$, 0.3m/sec. The results were as follows: The average skin temperature and hand, thigh temperature of B were higher than B and Ctrl. (p<.05). The micro-climates of B were near to thermal comfort range which is $32{\pm}1^{\circ}C$ and $50{\pm}10%\;RH$. The chest temperature of B was significantly higher than others (p<.05). The relative humidity of B was lower than others and kept stable rather than others. The thermal sensation of B was near the "neutral" and was significantly different from Ctrl. (p<.01) and the weight loss of B was lower than Ctrl. (p<.05). The counting task and hand temperature was positively related and the counting task value of B and A is bigger than Ctrl. and that of A was bigger than Ctrl. (p<.05).

Study on the Room Temperature Degreasing Conditions of Steel Sheet for Electrogalvanizing (전기아연도금용 강판의 상온 탈지 조건 연구)

  • Tae-Yeon Park;Chae-Won Kim;Su-Mi Yang;Hee-Jun Hong;In-Chul Choi
    • Journal of the Korean Society for Heat Treatment
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    • v.37 no.1
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    • pp.16-22
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    • 2024
  • The conventional degreasing process involves removing oil and contaminants at temperatures above 80℃, resulting in excessive energy consumption, increased process costs, and environmental issues. In this study, we aimed to find the optimal degreasing conditions for the pre-treatment process of electro-galvanizing cold-rolled steel sheets, conducted efficiently at room temperature without the need for a separate heating device. To achieve this, we developed a room temperature degreasing solution and a brush-type degreasing tool, aiming to reduce energy consumption and normalize the decrease in degreasing efficiency caused by temperature reduction. Alkaline degreasing solution were prepared using KOH, SiO2, NaOH, Na2CO3, and Sodium Lauryl Sulfate, with KOH and NaOH as the main components. To enhance the degreasing performance at room temperature, we manufactured additives including sodium oleate, sodium stearate, sodium palmitate, sodium lauryl sulfate, ammonium lauryl sulfate, silicone emulsion, and EDTA-Na. Room temperature additives were added to the alkaline degreasing solution in quantities ranging from 0.1 to 20 wt.%, and the uniformity of degreasing and the adhesion of the galvanized layer were evaluated through Dyne Test, T-bending Test, OM, SEM, and EDS analyses. The results indicated that the optimal degreasing solution composition consisted of NaOH (30 g/L), Na2CO3 (30 g/L), SLS (6 g/L), and room temperature additives (≤1 wt%).

Study on the Characteristics of Ordinary Symptoms in Overweight and Obesity Patients according to Sasang Constitution (사상체질에 따른 과체중 및 비만 환자의 소증(素證) 특성 비교)

  • Shin, Seung Won;Lee, Junhee
    • Journal of Korean Medicine for Obesity Research
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    • v.13 no.1
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    • pp.33-45
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    • 2013
  • Objectives: This study was aimed to find out the characteristics of ordinary symptoms between the control and patient groups, diagnosed as overweight or obesity, in Soyang, Taeeum, and Soeum Constitutions and among those 3 groups. Methods: As a prospective cross-sectional study based on medical records, 9213 patients, who visited Kyung Hee University Medical Center from May in 2007 to June in 2010, were included. To diagnose the constitution, Revised Questionnaire for the Sasang Constitution Classification II and examinations by oriental medical doctors who majored in Sasang Constitution Medicine were performed. Based on the World Health Organization criteria for Asian obesity assessment, body mass index (BMI) was classified into 3 groups; more than 25 as obesity, 23 to 25 as overweight, and less than 23 as normal. Ordinary symptoms questionnaire, which consists of 46 questions in 8 categories, were given to the subjects. One-way ANOVA test in continuous variables and chi-square test in categorical variables were carried out to analyze statistical significance. Results and Conclusions: 1) In general characteristics, we could find out the significant differences in age, sex, height, weight, BMI, waist circumference, blood pressure, total cholesterol, triglyceride, low density lipoprotein cholesterol, high density lipoprotein cholesterol, fasting blood sugar, and hemoglobin A1c among the 3 Constitutional groups. 2) Soyang Constitution of overweight and obesity has tendency to have higher appetite, like cool or cold water, defecate more, swear more, dislike heat, and have warmer or hotter extremities in the ordinary symptoms, compared with the control group. 3) Taeeum Constitution of overweight and obesity has tendency to have higher appetite, like cool or cold water, defecate more, swear more, dislike heat, and have warmer or hotter extremities in the ordinary symptoms, compared with the control group. 4) Soeum Constitution of overweight and obesity has tendency to have higher appetite and less fatigue in the ordinary symptoms, compared with the control group. 5) Soeum Constitution showed the slightest increase in appetite, preference about room temperature water, less number of feces, and feeling of chill and warmer extremities in ordinary symptoms, compared with Soyang and Taeeum Constitutions. Taeeum Constitution showed the distinct increase in appetite and sweating in ordinary symptoms, compared with Soyang and Soeum Constitutions.

Development and Validation of Cryopanel Cooling System Using Liquid Helium for a Satellite Test (액체헬륨을 이용한 위성시험용 극저온패널 냉각시스템 개발 및 검증)

  • Cho, Hyok-Jin;Moon, Guee-Won;Seo, Hee-Jun;Lee, Sang-Hoon;Hong, Seok-Jong;Choi, Seok-Weon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.2
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    • pp.213-218
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    • 2010
  • A cooling system utilizing liquid helium to chill the cryopanel (800 mm $\times$ 700 mm dimensions) down to 4.2 K was designed, implemented, and tested to verify the role of the cryopanel as a heat sink for the payload of a spacecraft inside the large thermal vacuum chamber (effective dimensions : 8 m ($\Phi$) $\times$ 10 m (L)) of KARI (Korea Aerospace Research Institute). Two LHe (Liquid Helium) Dewars, one for the main supply and the other for refilling, were used to supply liquid helium or cold helium gas into this cryopanel, and flow control for the target temperature of the cryopanel within requirements was done through fine adjustment of the pressure inside the LHe Dewars. The return helium gas from the cryopanel was reused as a thermal barrier to minimize the heat influx on the core liquid helium supply pipe. The test verified a cooling time of around three hours from the ambient temperature to 40 K (combined standard uncertainty of 194 mK), the capacity for maintaining the cryopanel at intermediate temperatures, and a 1 K uniformity over the entire cryopanel surface at around 40 K with 20 W cooling power.

A Study on the Standard Test Method for Thermal Resistance of Military Textile Thermal Insulator for Winter Season (방한을 목적으로 하는 군용 섬유제품 충전재의 보온성 시험방법에 대한 표준화 연구)

  • Yeo, Yong-heon;Hong, Seong-don;Lee, Min-hee;Kim, Kyung-pil;Chung, Il-han
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.9
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    • pp.492-500
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    • 2018
  • The performance evaluation of cold weather clothing is mainly carried out with thermal resistance. However, the results of the revised test method regarding the same specimen were decreased compare to previous one. In addition, there were deviations of the results among the authorized testing institutes according to the different interpretation of the KS test method. This makes it a considerable difficulty to the quality assurance of combat supplies. The purpose of this study is to minimize the variation of the results before and after the revision by analyzing the cause of the decrease in the heat insulation rate according to the revised test method. For this purpose, the difference between the test conditions before and after the revision of KS is analyzed and the possible results are reviewed. In addition, we want to minimize the result deviation between testing laboratories by analyzing the cause of the result deviation between test laboratories according to arbitrary interpretation of the standard. Based on this, we propose a standardized test method to prevent the decrease of the heat insulation rate by checking the pre-revision test method and the condition with the least deviation.

Development and Performance Test of a l00hp HTS Motor

  • Sohn, M.H.;Baik, S.K.;Lee, E.Y.;Kwon, Y.K.;Yun, M.S.;Moon, T.S.;Park, H.J.;Kim, Y.C.;Ryu, K.S.
    • Progress in Superconductivity and Cryogenics
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    • v.6 no.4
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    • pp.27-31
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    • 2004
  • This paper describes the development and fabrication of a high temperature superconducting motor which consists of HTS rotor and air-core stator. The machine was designed for the rated power of 100hp at 1800 rpm. The HTS field windings are composed of the double-pancake coils wound with AMSC's SUS-reinforced Bi-2223 tape conductor. These were assembled on the support structure and fixed by a bandage of glass-fiber composite. The cooling system is based on the heat transfer mechanism of the thermosyphon by using GM cryocooler as cooling source. The cold head is in contact with the condenser of a Ne-filled thermosyphon. The rotor assembly was tested independently at the stationary state and combined with stator. Characteristic parameters such as reactances, inductances, and time constants were determined to obtain a consistent overview of the machine operation properties. This motor has met all design parameters by demonstrating HTS field winding, cryogenic refrigeration systems and an air-core armature winding cooled with air. The HTS field winding could be cooled down below 30K. No-load test of open-circuit characteristics(OCC) and short-circuit characteristics(SCC) and load test with resistive load bank were conducted in generator mode. Maximum operating current of field winding at 30K was 120A. From OCC and SCC test results synchronous inductance and synchronous reactance were 2.4mH, 0.49pu, respectively. Efficiency of this HTS machine was 93.3% in full load(100hp) test. This paper will present design, construction, and basic experimental test results of the 100hp HTS machine.