Pd/C 촉매에 의한 2-(2-hydroxy-5-methyl-phenyl)-2H-benzotriazole 합성 반응의 특성

최주홍,이정원,이대광,이동근 慶尙大學校生産技術硏究所 1994 生産技術硏究所論文集 Vol.10 No.-

The reduction process using Pd catalyst is very attractive in the view points of the simple reaction step and the relatively less discharge of pollutants. The reduction characteristics of o-nitrohydroxyazobenzene(O-NHAB) with Pd/c catalyst was investigated in an autoclave and a reactor operated at atmospheric pressure. The reduction performance of O-NHBA in the auto clave showed high pressure gave good yield for tinuvin P. The maximum yield of tinuvin P based on o-nitroaniline was 63.3%. Some contents of water in the solution improved the reaction rate ad reduced the formation of impurities. Reaction temperature was able to be increased up to 75℃ with the relatively less impurities. The optimum content of NBA was about 10%.

우리나라 유방아마에서 CYPIA1, EPHX 유전자 다형성의 역할

최지엽,유정희,이은옥,유근영,박수경,안세현,노동영,최국진,강대희 대한암예방학회 2002 Journal of cancer prevention Vol.7 No.3

하악 제3대구치가 하악 우각부골절 정복술후 감염에 미치는 영향에 관한 연구

최문기,민승기,이동근,오승환 대한악안면성형재건외과학회 2001 Maxillofacial Plastic Reconstructive Surgery Vol.23 No.3

Any fracture passing through the socket of a teeth is compounded intraorally, even if the fracture is not displaced and the tooth is firm in its socket. Before the advent of antibiotic therapy the danger of infection in a compounded fracture posed severe problems in treatment. Infection is reduced by antibiotic therapy but prolonged use of antibiotics is not justified in an attempt to save a tooth which might eventually be sacrificed. There is still controversy in the management of third molar in mandibualr angle fracture, particularly in regard to their retention or removal at the time of fracture treatment. So we surveyed the 159 patients who were treated with open reduction of mandibular angle fracture containing third molar in fracture line, and compared with the postoperative infection rate depending on time intervals between injury and operation, eruption state of third molar, non-extraction or extraction of third molar related to eruption state, non-extraction or extraction of third molar related to condiition of third molar and its surrounding periodontium and were to propose treatment guidline of third molar in mandibular angle fracture The results obtained were as follows : 1.There were no statistical significance between the time from injury to operation and postoperative infection. 2.There were no statistical significance between eruption state of third molar and postoperative infection. 3.In case of retention of the third molar, there were no statistical significance between eruption state of third molar and postoperative infection, but in case of extraction, postoperative infection was high rate in complete impacted cases. 4.There were no statistical significance between non-extraction or extraction of third molar and postoperative infection depending on condition of third molar. There are no difference in infection rate statistically according to the time from injury to operation, eruption state and condition of third molar, but retention of third molar revealed lowered infection rate in completely impacted cases. By terms of the manegement of third molar, we should extract or preserve third molar in the line of the mandibular angle fracture according to possibility of infection.

햄스터 구강암 발생 과정에서 Heat Shock Protein에 관한 면역조직화학적 연구

최규환,이동근,김은철,정창주 대한악안면성형재건외과학회 2001 Maxillofacial Plastic Reconstructive Surgery Vol.23 No.2

A IMMUNOHISTOCHEMICAL STUDY ON HEAT SHOCK PROTEIN IN ORAL CARCINOGENESIS IN HAMSTER Heat shock protein (HSP) expression is unto·emulated in tumor cells and, HSP expression is likely marker of the malignant potential of oral epithelial lesion. Furthermore, the 70kDa HSP is implicated in the degree of tumor differentiation, the rate of tumor proliferation and the magnitude of the anti-tumor Immune response. Accordingly, the distribution and intensity of HSP70 and HSP47 expression was assessed in the DMBA induced oral carcinogenesis in hamster. Golden Syrian hamsters which were 3 months-age and 90∼120g were collected. 9,10-dimethyl -1,2-ben-zanthracene (DMBA) in a 0.5% solution in mineral oil was painted on the buccal pouch mucosa 3 times per week in the study group. In each control and experimental groups of 6, 8, 10, 12, 14, 16, 18, 20 weeks, specined for immunohistochemical study with anti-HSP47 and anti-HSP70 antibody. The following results were obtained. 1.HSP47 positive cells were race or negative of normal oral mucosa, increased mildly in basal and suprabasal basal layer, and spinous cell layer after experimental 6 weeks (dysplastic or CIS stage). In CIS stage, HSP47 expression is prominent in dysplastic free or normal adjacent epithelium. 2.HSP47 positive cells in connective tissue were mainly inflammatory cells, which is gradually increased from control to precancerous and cancer stage. But HSP47 positive cells after 14 weeks were decreased, especially normal and cancer adjacent epithelium. 3.The positive staining cells of HSP70 in control, dysplastic, and CIS stage were not seen. But they were mild findings in basal layer and moderate findings in spinous layer after experimental 14 weeks (cancer stage). 4.HSP70 positive cells were increased in precancerous and cancer stage than control group in connective tissue. After experimental 16 weeks, we could not find the HSP expression in cancer cells according to cancer differentiation or cancer stage. It is concluded that HSP70 or HSP47 expression is not a definitive marker of oral malignancy or malignant potential. However, with further development, HSP immunoreactivity may be valuable as an adjunct to conventional histology for assessing the malignant potential of oral mucosal lesions.

Mask modification for the shadow effect reduction by rigorous coupled-wave analysis in extreme ultraviolet lithography

최민기,신동수,오혜근 한양대학교 이학기술연구소 2005 이학기술연구지 Vol.8 No.-

극자외선 리소그래피는 파세대 리소그래피 기술로 유력시 되고 있으며 세계적으로 널리 연구되고 있는 기술이다, 극자외선 리소그래피에서 마스크의 구조는 near-field intensity 분포에 영향을 끼친다, 마스크로 들어가는 빛의 사입사 각도에 따라 흡수체 층과 버퍼층은 그림자를 만들며 이러한 그림자 효과는 극자외선 리소그래피 마스크에서 aerial image contrast를 줄이며 결과적으로 패턴의 위치 이동을 야기시킬 수 있는 중요한 요소로 작용한다. 우리는 극자외선 리소그래피에서 일반적인 사입사 각도인 5˚로 마스크 흡수체 패턴의 옆면을 변형하였다, 변현된 마스크 에서의 전자기파와 반사도는 rigorous coupled-wave analysis를 이용하여 계산하였다. Extreme ultraviolet lithogrphy (EUVL) is believed to be the next generation lithography and so it is seriously under study globally The near-field intensity on the EUVL mask is affected by the mask structure The absorber and the buffer layer make a shadow since the light is shining on the mask at some angle to the normal on-axis This shadow effect in th EUVL mask is an important factor that decreases the contrast of the aerial image and as a result causes line-width variation and pattern shift Among the several possible mask structures we focused on the mask edge slope variation with a typical incident angle of 5˚ We analyzed electromagnetic wave around the mask by rigorous coupled-wave analysis (RCWA) and reflectivity in the modified mask structure

2-Methylisoborneol(2-MIB)제거를 위한 산화 및 흡착공정의 특성

최근주,김상구,류동춘,신판세,손인식,오광중 한국환경과학회 2002 한국환경과학회지 Vol.11 No.3

One of the Musty and earthy smell compounds in raw water is generally attributed to 2-methylisoborneol (2-MIB). It is well known that activated carbon and oxidants such as O_3, ClO_2 are effective ways to control 2-MIB. In isotherm equilibrium experiments, 2-MIB in distilled water was much more adsorbed to the activated carbon(A/C) than raw water containing dissolved organic carbon (DOC). The Freundlich constants(k) of distilled water and raw water were 3.36 and 0.049, and 1/n values were 0.80 and 0.42, respectively. The 2-MIB residual rate were Y = e^(0.55_x)~ e^(-0.54_x) with Ozone(O_3) dose by 5 minutes contact time at the 241 and 353 ng/L initial concentrations. The 2-MIB residual rate were Y = e^(-0.32_X)~ e^(-0.35_X) with Chlorine dioxide(ClO_2) dose by 15 minutes contact time at the 89 and 249 ng/L initial concentrations. 2-MIB was decreased from 1911 ng/L to 569ng/L by post-ozonation(70%removal efficiency) and removal efficiencies of 2-MIB by the following 4 kinds Granular Activated Carbon(GAC) process such as coal base, coconut base, wood base and zeolite+carbon base were 95.8, 89.5, 88.4, and 93.7% respectively.

장애학생을 위한 검사 조정과 학업성취 수준 분석

최종근,김동일,김은주 국립특수교육원 2005 특수교육연구 Vol.12 No.1

본 연구는 장애학생들이 국가수준 학업성취도 평가에 본격적으로 참여하기에 앞서, 이들 장애학생들에게 요구되는 검사 조정 방안을 모색하고 이들의 기초학습 및 기본학습 능력 수준을 파악하기 위하여 이루어진 전국규모의 조사연구이다. 본 연구를 위해 일반학생 520명과 전국 29개 특수학교 중등부 3학년 학생(시각, 청각, 지체부자유) 144명의 성취수준과 부진학생 비율을 비교하였다. 분석 결과, 한국 장애학생의 기초학습 부진학생 비율은 일반학생의 3-5% 내외에 비해 훨씬 많은 30-50% 안팎에 이르고, 기본학습부진학생(보충학습 대상자) 비율도 일반학생의 10% 내외에 비해 훨씬 많은 60-70% 안팎에 이르는 것으로 나타났으며 특히 청각장애학생의 학업성취수준이 낮은 것으로 나타났다. 따라서 향후 정책적인 측면에서 장애학생들의 기초학습 기능 및 학업성취 수준을 향상시키기 위한 교육의 질 제고에 초점을 두어야 할 것이다. The purpose of this study was to compare the basic learning skill and academic achievement test score of students with disabilities(SWD) with those of general education students', and to identify the change of request for test modification or accommodations(TA) of SWD before and after the test. The participants of this study were 144 9th-grade SWD(the visually impaired, the hearing impaired, and the physically handicapped) from 29 special schools nation-wide, and 520 9th-grade general education students from a school from metropolitan area. In this study, SWD could choose any kind of TA among presentation, response, timing or scheduling, and setting/others. The results could be summarized as follows: (a) Compared to general 3-5%, 30-50% of SWD were categorized as defecting basic learning skill, and compared to general 10%, 60-70% of SWD were categorized as underachievers(in reading, writhing, and math). (b) SWD requested unexpectedly various test accommodations. (c) In order to attain the "appropriate" TA, a well-designed research on impacts of TA should be conducted in the future.

확산 화염 반응기에서의 TiO_2 입자생성 및 전달현상

최상근,김동주,김교선 江原大學校 産業技術硏究所 2002 産業技術硏究 Vol.22 No.A

We prepared the nano-sized TiO_2 particles by the diffusion flame reactor and investigated the effects of several process variables on the generation and transport properties of TiO_2 particle. As the length from the tip of diffusion flame reactor increases, the size of TiO_2 particle increases by the coagulation between particles. The structure of TiO_2 particles prepared is almost found to be anatase. It was found that the TiO_2 particle size depends more largely on the change of reactor temperature than on the change of inlet TiCl_4 concentration.

나노 사이즈 TiO_2 광촉매를 이용한 페놀 분해

최상근,김동주,김교선 江原大學校 産業技術硏究所 2001 産業技術硏究 Vol.21 No.A

In this study, we prepared nano-sized TiO2 particles for various process variables by the diffusion flame reactor and we collected TiO2 particles by thermophoresis. It is found that the size of TiO2 particles increases, as the flame temperature or the inlet TiCl4 concentration increase or the total gas flow rate decreases. We investigated the photo-degradation of phenol wish the prepared TiO2 particles. We found the optimum amounts of TiO2 photocatalysts for our experimental apparatus and investigated the photo-degradation efficiencies of phenol, changing the process variables such as size of TiO2 photocatlysts, phase ratio of rutile/anatase, concentration of phenol, input ratio of O2. Degradation efficiencies of phenol were almost 95% in 15 minutes for the standard conditions of our experiments.

분무 열분해에 의한 Ba1-xSrxFe12O19계 자성 미립자의 제조 및 특성 변화

김동현,김광만,김경남,최세영,심인보,이용근 大韓齒科器材學會 2004 대한치과재료학회지 Vol.31 No.1

Magnetic particles with alternating magnetic field are expected to be useful as thermoseeds in hyperthermic cancer treatment, since they can be targeted and confined to the cancer site. Hard magnetic ferrites such as barium ferrite and strontium ferrite are good candidates for thermoseeds of hyperthermia because of their great hysteresis loss. In order to verify the effect of Sr-substitution to Ba-site, synthesized Ba1-xSrxFe12O19 microspheres with various compositions through spray pyrolysis followed by sol synthesis using barium nitrate, strontium acetate and iron nitrate. Coercive force was increased with increasing substitution amount of Sr whereas magnetic saturation was almost constant. Spherical microspheres with average diameter of 11.7~17.0 ㎛ were produced by spray pyrolysis at 400~1000℃. The mean size was dependent on the pyrolysis temperature and flow rate of carrier gas. In order to obtain a single phase of SrFe12O19 crystal, the spray pyrolyzed spheres were undertaken subsequent heat-treatment above 1000℃. During the subsequent heat-treatment, however, spherical microspheres were agglomerated because of necking between particles. Further study has to be continued working on synthesis of pure SrFe12O19 crystal by means of improvement of pyrolysis temperature scheme and extend the heating period.