• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2000.04a
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• pp.255-260
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• 2000

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.6
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• pp.523-538
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• 2009

Recently, there has been a keen demand for real-time automatic monitoring of VOCs not only in Korea but other developed countries. We carried out this study to evaluate and to optimize the performance of a continuous automatic monitoring system for hazardous VOCs (HVOCs) in the ambient atmosphere, using an on-line GC system. The online system normally consisted of a Nafion dryer prior to a cold trap of an automatic thermal desorption apparatus and a GC system equipped with two detectors, i.e. PID and ECD. Preliminary tests conducted to check out any contamination of the system revealed an evidence of significant artifact formation of benzene, and it was found that the Nafion dryer (even brand new one) is the source of the benzene artifact. Thus, all the subsequent experiments in this study was carried out inevitably by removing the Nafion dryer. The on-line GC method was investigated with a variety of QC/QA performance criteria such as repeatability, linearity, lower detection limits, and accuracy. In order to find out the best operating condition for the on-line GC system, three different types (in terms of adsorption strength) of cold trap combinations were tested, i.e. (i) Tenax-TA and Carbopack-B combination (weak and hydrophobic); (ii) Tenax-TA, Carbopack-X and Carboxen-1000 combination (strong and hydrophilic); and (iii) Tenax-TA and Carbopack-X combination (medium and hydrophobic/hydrophilic). The USEPA TO-17 manual method was selected as a reference method to evaluate the performance of the on-line method. A series of experiments revealed that the system performance was superior to others when a cold trap packed with hydrophilic adsorbents (Tenax-TA/Carbopack-X/Carboxen-1000 combination) was used and operated at $25^{\circ}C$. However, the system with a cold trap packed with a combination of Tenax-TA and Carbopack-X is more recommended for field applications since the carboxen-1000 adsorbent is too sensitive to water vapor, and hence the performance of the system might be very unstable to humid samples or during rainy days. Furthermore, the precision and accuracy criteria of the Tenax-TA/ Carbopack-X combination were generally compatible with the triple adsorbents cold trap. The continuous automatic monitoring method is, thus, considered very useful to real-time monitoring to understand the variations of VOCs concentrations in ambient air, as it adopts much simpler procedures in sampling, analysis, and data integration steps than manual monitoring methods. However, it should be noted that there is a high possibility of benzene artifacts formation through the Nafion dryer, which is often installed to remove water vapor in air samples before being adsorbed onto the cold trap. Therefore, if a Nafion dryer is used in any studies of monitoring VOCs, the benzene contamination should be carefully examined before carrying out obtaining the data.

• Journal of the Semiconductor & Display Technology
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• v.23 no.1
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• pp.92-96
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• 2024

The application of the technology for forming Al₂O₃ thin films using ALD(atomic layer deposition) method is rapidly increasing in the semiconductor and display fields. In order to increase the efficiency of the ALD process in a mass production line, metallic by-products generated from the ALD process chamber must be effectively collected. By collecting by-products flowing out of the chamber with a cold trap device before they go to the vacuum pump, damage to the vacuum pump can be prevented and the work room can be maintained stably, resulting in increased process flow rate. In this study, a cold trap was installed between the ALD process chamber and the dry pump to measure and analyze by-products generated during the Al₂O₃ thin film deposition process. As a result, it was confirmed that Al and O elements were discharged, and the collection forms were two types: bulk and powder. And the binding energy peaked at 73.7 ~ 74.3 eV, the binding energy of Al 2p, and 530.7 eV, the binding energy of O 1s, indicating that the binding structure was Al-O.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.93.1-93.1
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• 2015

근래 디스플레이 분야에서 OLED가 시장을 주도하면서 이 공정에 가장 적합한 진공펌프로 크라이오 펌프가 주목을 받고 있다. 화소 형성 공정에 사용되는 유기물이 수분에 취약하기 때문인데, 크라이오 펌프가운데서 특별히 수분만 집중적으로 배기할 수 있는 워터펌프(CWP or cold trap)가 각광받고 있다. 이에 HM GVT는 중소기업청 중소기업개발지원사업의 일환으로 진행된 2014년도 구매조건부 신제품 개발사업에 선정되어 '극저온 G-M냉동기를 이용한 대용량 Cold Trap개발' 과제를 수행하면서 32인치 급으로 수분에 대해서 30,000 [L/s] 이상의 배기속도를 가지는 대형 CWP를 개발하고 있다(수요처: (주)아바코). 통상적으로 흡기구가 30인치라면 수분 배기속도는 대략 65,000 L/s에 이르고 200 W 냉각능력이면 최대 수분 분압 0.008 mbar에서 작동시킬 수 있다. 따라서 1차년도의 목표는 큰 배기용량과 대형 사이즈의 CWP를 개발하기 위해 80 K에서 200 W 이상의 냉동능력을 보유한 단단 G-M 극저온냉동기를 선행 개발하는 것이다. 이에 현재 최대 냉동능력 80 K에 130 W의 냉동능력을 가지는 HPS055모델을 이용하여 다양한 예비시험들을 수행하여 최적의 설계인자들을 도출하였고 이를 근거로 80 K에서 200 W 이상의 냉동능력을 가지는 HPS80200모델을 설계 및 제작, 성능시험을 수행하였다. 이에 국내 최초로 80 K에서 200 W의 냉동능력을 가지는 단단 G-M냉동기를 개발하였고 설계 및 제작에 대한 원천기술을 확보할 수 있었다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.11 no.4
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• pp.183-188
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• 1978

In this study, gas chromatographic analysis was carried out on volatile constituents of cooked squid for the object of obtaining information on the characteristic flavor of the cooked squid meat. The results obtained are as follows: 1) Methanol was the most effective solvent for the extraction of volatile constituents of squid meat. 2) Twenty five and thirty two peaks were detected from the condensate collected in cold traps which were immersed in ice water and dry ice-acetone, respectively. In these compounds, five kinds of volatile organic acids such as acetic acid, butyric acid, iso-valeric acid, valeric acid, and caproic acid were identified. 3) Eleven peaks were detected from the head space vapor collected in cold trap which is immersed in liquid nitrogen. Volatile amines identified in these components are as follows; methylamine, trimethylamine, dimethylamine, ethylamine, and iso-propylamine.

• Journal of Welding and Joining
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• v.5 no.1
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• pp.34-41
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• 1987

To explore the possible application of thermal analysis technique as a probe for finding weld defects, Hydrogen trapping phenomena in Heat Affected Zone (HAZ) of the AISI 5160 spring steel were investigated. HAZ was divided into five parts, which were used as thermal analysis specimens. Two types of trap sites were found in HAZ, ferrite/cementin interface and microvoid. The thermal analysis peak due to the ferrite/cementite interface increased its height toward the weld deposit. The thermal analysis peak due to the microvoid was the highest where the grain size was the smallest. The correspondence between the cold cracking and hydrogen trap nature is also discussed.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.1
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• pp.61-68
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• 2000

Gas-phase hydrogen peroxide(H2O2) concentrations were measured to investigate it's distribution in the ambient air in downtown Seoul(Kwanghwamum and Mullae-dong). These measurements were made during four season, from April 30, 1998 to January 29, 1999, using Cold Trap and HPLC. Measurements were also made of other photochemical oxidants and trace gases(O3, NO2, CO and SO2) and meteorological parameters(relative humidity, temperature, solar radiation and wind speed). The mean of all observations was 0.10 ppbv and the range measured was below the level of detection(>0.01 ppbv) to 0.47ppbv. The higher seasonal mean concentrations showed during the summer(0.21 ppbv) and concentrations of H2O2 showed a diurnal variation with maximum concentrations in the afternoon(12:30∼14:00). The results from the corrrelation analysis showed that the concentration of gaseous H2O2 is strongly dependent on the other air pollutants(NO2, CO and O3) and meteorological parameters(relative humidity, temperature and solar radiation.)

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.109.1-109.1
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• 2016

진공산업 분야에서 OLED 디스플레이가 큰 시장으로 성장하며 크라이오 펌프가운데서 특별히 수분만 집중적으로 배기할 수 있는 워터펌프(CWP or cold trap)가 각광받고 있다. 이에 현민지브이티(Genesis)는 중소기업청 중소기업개발지원사업의 일환으로 진행된 2014년도 구매조건부 신제품 개발사업에 선정되어 '극저온 G-M냉동기를 이용한 대용량 Cold Trap개발'과제를 수행하면서 32인치 급으로 수분에 대해서 30,000[L/s] 이상의 배기속도를 가지는 대형 CWP를 개발하고 있다. 그 일환으로 본 CWP에 장착할 80K에서 200W급 단단 G-M 냉동기를 2015년 국내 최초로 개발하였다. 본 HPS80200(200W @80K) 단단 G-M냉동기에 대한 성능시험을 수행하던 중 기존 평가방식에 보완할 부분이 있음을 확인하였다. 통상적으로 G-M냉동기의 냉동능력은 저온 스테이지 상단에 온도센서와 히터가 설치된 히터 블럭을 장착한 후 일정한 열부하를 인가하면서 77K 또는 80K에서의 냉동능력을 측정한다. 문제는 여기에 설치하는 온도센서의 장착 위치의 중요성이다. 즉, 어느 부위의 온도를 냉동기의 대표 온도로 정하느냐에 따라 냉동기의 성능 값에 큰 차이를 나타내기 때문이다. 실제 확인 결과, 온도는 히터블럭 내의 위치뿐 아니라 저온 스테이지 부위별로도 크게 차이를 보였다. 따라서 본 연구에서는 보다 합리적이고 정확한 냉동 능력 측정을 위해 77K 에서 냉동기의 질소 액화 능력으로 냉동능력을 평가하고자 하였다. 이를 통해 개발된 HPS80200냉동기의 보다 정확한 냉동능력(77K에서 200W 이상임을 확인함)을 측정할 수 있었고 냉동기의 저온 스테이지에서 대표온도로 설정할 수 있는 위치도 확인할 수 있었다.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.89-90
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• 2005

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.5
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• pp.208-215
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• 2016

This study was conducted to improve the performance of low-temperature vacuum dryer by applying desiccant to cold trap. Performance evaluation was carried out using several desiccants. The amounts of absorption and diffusivity were measured based on analytic model. Results of desiccant performance evaluation revealed that silica-gel had the most excellent performance for conditions of low-temperature vacuum drying process. Silica-gel was applied to cold trap for evaluating the drying performance. The experiment results showed that the drying time was extended as the thickness of sample was increased due to increased heat and mass transfer resistance of drying sample. In addition, as heating plate temperature was increased, drying time was decreased due to increased evaporation pressure of drying sample. Furthermore, drying time with desiccant was decreased approximately 20% than that without desiccant.