HFCVD법에 의한 H₂ 다이아몬드 박막 제조에 수소가 미치는 영향

이권재,신재수,권기홍,이민수,고재귀,Lee Kwon-Jai,Shin Jae-Soo,Kwon Ki-Hong,Lee Min-Soo,Koh Jae-Gui 한국재료학회 2004 한국재료학회지 Vol.14 No.12

The diamond thin films was deposited on Si(100) substrate by Hot Filament Chemical Vapor Deposition (HFCVD) method using supplied the $CH_{3}OH/H_{2}O$ mixtured gas with excess H_{2} gas. The role of hydrogen ion as the growth mechanism of the diamond deposit was examined and compared the $CH_{3}OH/H_{2}O$ with the $CH_4/H_2$. Pressures in the range of $1.1\sim290{\times}10^2$ Pa were applied and using $3.4\sim4.4$ kw power. It was investigated by Scanning Electron Microscopy(SEM) and Raman spectroscopy The H ion was etching the graphite and restrained from $sp^3\;to\;sp^2$. But excess $H_2$ gas was not helped diamond deposit using $CH_{3}OH/H_{2}O$ mixtured gas. It was shown that the role of hydrogen ion of deposited diamond films using $CH_{3}OH/H_{2}O$ was different from $CH_4/H_2$.

γ-Fe₂O₃ nano 입자의 광학적 특성에 관한 연구

이권재,안정희,신재수,김창만,오자끼 하지메,고재귀,Lee, Kwon-Jai,An, Jeung-Hee,Shin, Jae-Soo,Kim, Chang-Man,Ozaki, Hajime,Koh, Jae-Gui 한국재료학회 2006 한국재료학회지 Vol.16 No.12

The ${\gamma}-Fe_2O_3$ nano particles in the size range of $5{\sim}30$ nm were prepared by a chemical coprecipitation method. The nano particles were coated with 2nd surfactants for obtaining the water-based. The size effect of ${\gamma}-Fe_2O_3$ nano particles for the ultraviolet protection was investigated. The variation of the UV-Vis transmittance spectra as a function of wavelength for a ${\gamma}-Fe_2O_3$ nano particles were showed red-shifted increase with the particle size. The protective effects of UVA onset at near 469, 494, 591 nm for a particle size of 8.7, 9.1 and 12 nm. It is shown that the ${\gamma}-Fe_2O_3$ nano particles was good materials for protect of UV.

세포독성 평가를 통한 γ-Fe₂O₃ 나노입자의 생체안정성 및 약물전달효율

이권재,안정희,신재수,김동희,유화승,조종관,Lee, Kwon-Jai,An, Jeung-Hee,Shin, Jae-Soo,Kim, Dong-Hee,Yoo, Hwa-Seung,Cho, Chong-Kwan 한국재료학회 2010 한국재료학회지 Vol.20 No.3

This study examined the biostability and drug delivery efficiency of g-$Fe_2O_3$ magnetic nanoparticles (GMNs) by cytotoxicity tests using various tumor cell lines and normal cell lines. The GMNs, approximately 20 nm in diameter, were prepared using a chemical coprecipitation technique, and coated with two surfactants to obtain a water-based product. The particle size of the GMNs loaded on hangamdan drugs (HGMNs) measured 20-50 nm in diameter. The characteristics of the particles were examined by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-TEM) and Raman spectrometer. The Raman spectrum of the GMNs showed three broad bands at 274, 612 and $771\;cm^1$. A 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay showed that the GMNs were non-toxic against human brain cancer cells (SH-SY5Y, T98), human cervical cancer cells (Hela, Siha), human liver cancer cells (HepG2), breast cancer cells (MCF-7), colon cancer cells (CaCO2), human neural stem cells (F3), adult mencenchymal stem cells (B10), human kidney stem cells (HEK293 cell), human prostate cancer (Du 145, PC3) and normal human fibroblasts (HS 68) tested. However, HGMNs were cytotoxic at 69.99% against the DU145 prostate cancer cell, and at 34.37% in the Hela cell. These results indicate that the GMNs were biostable and the HGMNs served as effective drug delivery vehicles.

CH₃OH/H₂O 가스의 기상활성법을 이용한 다이아몬드 박막성장 과정에서의 OES분석

이권재,고재귀,신재수,Lee, Kwon-Jai,Koh, Jae-Gui,Shin, Jae-Soo 한국재료학회 2003 한국재료학회지 Vol.13 No.1

The intensity is measured as functions of both distance from filament to substrate and $CH_3$OH/($CH_3$OH+$H_2$O) ratio by OES(Optical Emission Spectroscopy) to investigate the effects of activation species such as $H_{\alpha}$, $H_{\beta}$, H$\Upsilon\;C_3$, CH on diamond film growth.$ H_{\alpha}$ increases as $CH_3$OH composition decreases, while CH increases as $CH_3$OH composition increases. The intensity of $H_{\alpha}$ decreases as the distance increases and that of CH increases as the distance increases. The intensities of other activation species of $H_{\beta}$, H$\Upsilon\;C_3$, do not vary as a function of measured position distance. It varies randomly. It means that various parameters for depositing diamond thin film can be explained by the intensity(density) change of activation species, as a function of the distance of the filament.

공기열원 히트펌프의 난방 성능특성에 관한 실험적 연구

이권재(Kwon Jae Lee),권영철(Young Chul Kwon),전종균(Chong Keun Chun),박삼진(Sam Jin Park),권정태(Jeong Tae Kwon),허철(Cheol Huh) 대한설비공학회 2011 설비공학 논문집 Vol.23 No.6

This paper presents the heating performance characteristics of the air source heat pump with air to water type. The heating capacity, COP, P-h diagram were measured at various operating conditions, air-side temperatures, relative humidities, and inlet/outlet water temperature under the standard heating condition of KS B 6275. The experimental data for the heat pump were measured using the air-enthalpy calorimeter and the constant temperature water bath. As the air-side temperature increases, the heating capacity and COP increase. The effect of the air-side relative humidities on the heat pump performance is insignificant. The heat pump performance on inlet and outlet water temperatures and air-side temperatures(-7, -11, -15℃) were studied. Heating capacity and COP increased about 27~39% with the air-side temperature increasing. Enthalpy between the front and the rear of condenser decreased about 6% by increasing of the inlet water temperature. These results can be utilized in the design of the air source heat pump system with air to water type.

이중관형 열교환기의 증발 열전달 특성에 관한 실험적 연구

이권재(Kwon Jae Lee),권오경(Oh Kyeong Kwon),김용찬(Yong Chan Kim),설원실(Won Sil Seol) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.11

An experimental investigation was carried out to examine the evaporative heat transfer characteristics in the double pipe heat exchanger using R-410a. The double pipe heat exchanger was helical coil type. The inner tube of double pipe heat exchanger was two types, spiral and circle. The experimental runs were carried out at a saturation temperature of refrigerant ranging between 5℃ and 15℃, and mass fluxes are 103.3~258.2 ㎏/㎡s. The inlet temperature of the water in the test section were 9℃, 12℃, 19℃ and 22℃. Heat transfer coefficient of refrigerant side of spiral type and circle type were 3.36~4.66 ㎾/㎡℃ and 2.64~3.86 ㎾/㎡℃. The pressure drop of refrigerant side for circle type was higher than that of spiral type at same mass flux. The effectiveness of spiral type and circle type were 0.34~0.66 and 0.19~0.57.

사회상황이야기를 활용한 실과 수업에서 얻게 된 특수교사의 실천적 지식

이권재 ( Lee Kwon-jae ),임경원 ( Lim Kyoung-won ) 대구대학교 특수교육재활과학연구소 2017 특수교육재활과학연구 Vol.56 No.3

이 연구의 목적은 지적장애·정서장애 특수학교에서 사회상황이야기를 활용한 실과 수업을 실행하는 과정에서 얻게 된 특수교사의 실천적 지식이 무엇인지 알아보는데 있었다. 연구목적을 달성하기 위해 실행연구 방법을 채택하였고, 연구 참여자는 연구자로서의 교사와 수업을 관찰하고 조언해줄 4명의 수업전문가로 구성하였다. 수업은 총 5차시를 실시하였고, 수업 실행, 관찰, 협의 및 반성, 그리고 개선된 수업을 실행하는 순환 과정에서 나타난 자료를 수집하였다. 수집된 자료는 반복적인 읽기와 분석적 메모를 추출하는 개방적 코딩방법을 사용하여 의미단위를 하위범주와 상위 범주로 분류하였고, 최종으로 도출된 자료는 삼각검증을 통해 연구의 진실성을 확보하고자 노력하였다. 사회상황이야기를 활용한 실과 수업에서 얻게 된 연구 결과는‘교사, 수업에서 사회상황이 야기를 만나다’, ‘수업, 준비부터 평가까지’, ‘수업 지킴이; 좌(左)환경, 우(右)자료!’의 3개 상위범주와 11개 하위범주, 39개의 의미단위로 분석되었다. 이 연구에서 얻어진 연구결과를 토대로 도출해 낸 결론은 다음과 같다; 첫째, 사회상황이야기를 활용한 실과 수업은 장애학생의 관심을 높이고 자발적인 참여를 유도할 수 있다. 둘째, 특수교사는 수업을 설계할 때, 수업 내용선정에서부터 수업평가에 이르기까지 각 단계별로 고려해야할 사항들을 꼼꼼히 체크해야 하며, 학생 중심의 수업이 될 수 있도록 노력하여야 한다. 셋째, 특수교사는 교육환경 조성과 수업자료 준비에 대하여 충분한 지식과 이해를 갖추어야 한다. The purpose of this study was to investigate what practical knowledge elementary special education teachers would acquire in a process of giving Practical Art lessons based on social stories at a special school for students with intellectual disabilities or emotional disorders. For that purpose, the study employed the method of action research. The research participants included four lesson experts to observe the investigator's lessons as a teacher and provide her with advice. Total five lessons were given, and all data were collected throughout the cyclic process of implementation of a lesson, observation, consultation and reflection, and implementation of an improved lesson. Collected data were processed with repetitive reading and open coding to identify analytical memos. The meaning units were divided into upper and lower categories. The final data were tested in triangulation to secure their truthfulness. There were total three upper categories of findings generated from the elementary Practical Art lessons based on social stories, and they were "the teacher, encountering a social story in a lesson," "a lesson, from preparation to evaluation," and "a lesson guard with the environment in the left and the data in the right!" The findings led to the following conclusions: First, social stories-based Practical Art lessons were able to increase the interest of students with disabilities and induce them to take voluntary part in. Secondly, special education teachers need to reflect the considerations and the students' needs at each stage from lesson organization, which marks the beginning of a lesson, to evaluation, which marks the conclusion of a lesson. Finally, special education teachers should equip themselves with enough knowledge and understanding about the creation of an educational environment and the preparation of lesson materials, which hold significant importance in the organization of lessons.

EEV를 적용한 지열히트펌프의 냉매절환 및 수절환 방식 성능특성 비교

이권재(Kwon Jae Lee),권오경(Oh Kyoung Kwon),차동안(Dong An Cha),김용찬(Yong Chan Kim) 대한설비공학회 2012 대한설비공학회 학술발표대회논문집 Vol.2012 No.6

This study is investigated performance characteristics of ground source heat pump using refrigerant switching and water switching. Ground source heat pump was tested performance characteristics by EEV opening. Pressure ratio of compressor with counter flow was lower than that of parallel flow about 10%. Pressure ratio was decreased about 35% with EEV opening increasing. Superheat on counter flow was higher than that of parallel flow about 10℃. Superheat was decreased about 6℃ with EEV opening increasing. Subcooling was slight changed with counter flow, parallel flow and EEV opening. Cooling capacity and COP with counter flow was higher than that of parallel flow about.

실외온습도 변화에 따른 히트펌프 칠러의 난방성능에 관한 실험적 연구

이권재(Lee, Kwon-Jae),이상재(Lee, Sang-Jae),김정석(Kim, Jung-Seok),이수광(Lee, Soo-Kwang),박경만(Park, Kyoung-Man) 한국산학기술학회 2010 한국산학기술학회 학술대회 Vol.- No.-

본 연구에서는 외기온습도에 따른 히트펌프 칠러의 난방성능을 조사하고자 하였다. 난방표준 온도조건에서 건구온도 및 습구온도 변화에 따른 히트펌프 칠러의 난방능력과 COP를 획득하기 위하여 항온항습 챔버와 항온수조를 사용하였다. 실험은 건구온도 7℃~17℃, 상대습도 67%~87%에서 수행하였다. 외기온도가 증가함에 따라 난방능력은 약 27%, COP는 약 28% 증가하였지만, 상대습도 증가에 따른 난방능력과 COP의 변화는 거의 없었다. 따라서 난방운전 시 건구온도의 영향은 크고, 상대습도의 영향은 미미함을 알 수 있었다.

냉각방법에 따른 산소발생기용 공기압축기 실험 연구

이권재(Kwon Jae Lee),김정석(Jung Seok Kim),이기원(Ki Won Lee),권영철(Young Chul Kwon),홍승훈(Seung Hun Hong) 대한설비공학회 2011 대한설비공학회 학술발표대회논문집 Vol.2011 No.7

In this experimental study, a water cooling system was applied for cooling the air compressor of a oxygen generator, instead of a conventionally used an air cooling system. At the outside temperature condition of 20℃ and 35℃, temperature of the air compressor head and the outlet air of the oxygen generator were measured for the water cooling system and the air cooling system. Temperature of the air compressor head and the outlet air of the oxygen generator increased with increase of the outside temperature. Temperature of the air compressor head and the outlet air of the water cooling system decreased about 10℃ at the outside temperature of 35℃.