ZnO:In 가스 감지막의 특성 및 응용

김영범,박종아,김진해,김권태,김정규,마대영,박기철 경상대학교 생산기술연구소 2001 工學硏究院論文集 Vol.1 No.-

The microsensors to detect NH3 gas were fabricated by continous deposition of In film by evaporation and ZnO film by rf magnetron sputtering onto the Si3N4 diaphragm that was prepared by MEMS technology. The sensors were heat-treated to dope In into the ZnO thin film. The electrical characteristics of sensitive films were studied as a function of heat-temperature by 4-point probing method and electrometer. The dependence of the sensitivity, selectivity and time response of sensor on heat-treatment temperature was investigated. The microsensor heat-treated at 400℃ that 3000 A ZnO:In film was chosen as gas sensitive film, showed the highest sensitivity 23% at 350ppm NH3 under 366mW heater power. The time response was 90sec. The sensitivity for CO and NOx was not observed.

다발성 대장암 간전이 환자의 간절제를 위한 새로운 시도

주종우,김형철,임철완,신응진,조규석,유기원,송옥평,홍대식,박성진,조준희,이혜경,김희경,권계원,고은석 순천향의학연구소;Soonchunhyang Medical Research Institute 2004 Journal of Soonchunhyang Medical Science Vol.10 No.2

Multiple bilobar liver matastases (MBLM) are the main cause of low resectability in the colon cancer liver metastases. The authors experienced one case of initially non-resectable colon cancer liver metastases. He was curatively and safely treated with a two-stage hepatectomy using the new method of future remnant liver volume growing. A 54-year-old man was referred to our department with the sigmoid colon cancer combined with MBLM, which were checked in two small metastatic lesions in the left lobe and five large sized lesions in the right lobe in the computed tomogram (CT). A laparoscopic assisted anterior resection was primarily performed. We performed the 1^(st) stage hepatectomy 3 weeks after the colon resection. Intra-operative Ultrasonogram (US) found 9 small superficial metastatic lesions in the left lobe. All that lesions were completely removed by non-anatomical wedge resection. An occlusion ballon catheter was placed in the right portal vein through a small branch of the inferior mesenteric vein at that time. The future remnant liver volume was sufficiently increased 3 weeks after the 1^(st) hepatectomy. A right hepatectomy was safely performed 22 days after the 1^(st) hepatectomy. The patient received a regional chemotherapy (interleukin2 based immuno-chemotherapy through hepatic artery) for 4 months, then received 9 cycles of systemic chemotherapy (biweekly Oxaliplation, leucovorin, plus 5-fluorouracil) without any recurrence evidence.

수종 유기산 용액에서 글라스 아이오노머 시멘트의 표면조도 및 색 변화에 관한 연구

김용대,문현정,임범순,김철위 대한치과기재학회 1997 대한치과재료학회지 Vol.24 No.2

The chemical bonding ability of glass ionomer cement to tooth structure and sustained fluoried release render glass ionomer cements advantageous over other restorative materials, such a amalgam and composite resins. Poor polishability and high solubility in organic solvents, however, are still a significant disadvantage of the existing glass ionomer cements. The purpose of this study was to estimate the aging effect of glass ionomer cements in organic acid solutions on surface change and color change. Using metal molds, disk type speciments, 100mm×1mm were prepared from three chemical-curing and three light-curing glass ionomer cements. Specimens were prepared from each material following the manufacturer's intructions, and setted against a mylay matrix strip supported by a glass slab. Three specimens were prepared for each experimental groups. Profilometric analyses were carried out using the surface roughness tester(Surtronic 3P, Rank Taylor Hobson Ltd. England). R?? valuse, which were the mathematical mean values of the departure of the roughness profile from the mean line calculated by the machine, recorded. Color measurements(CIE coefficients ; L, a, b) were peformed using the spectrophotometer(CM-3500d, Minolta, Japan). Before aging treatment and after 1, 7, 14, 21, and 28 days aged at 37℃ in a various organic and solutions(such as acetic acid, lactic acid and citric acid) and deionized water, surface roughness and color coefficients measuements were carried out. Then, surface roughness changes(ΔRa) and (ΔE) of specimens were calcuiated. From the experiment, the following results were obtained : 1. Chemical-cured glass ionomer cements showed statistically surface roughness changes after aged in the deionized water(P<0.10), and light-cured glass ionomer cements showed statistically significant color changes after aged in the deionized water(P<0.10). 2. Chemical-cured glass ionomer cements showed statistically color changes after aged in acetic acid solutions (P<0.10), and light-cured glass ionomer cements did not showed statistically significant surface roughness changes, but showed statisticall significant color changes after aged in acetic acid solutions (P<0.10). 3. Chemical-cured glass ionomer cements did not showed statistically significant color changes as a function of concentration of lactic acid solutions (p>0.10), and light-cured glass ionomer cements showed statistically significant color changes after aged in acetic acid solutions. 4. Chemical-cured glass ionomer cements did not showed statistically significant surface roughness changes as a function of concentration iof lactic acid solutions (p>0.10), but showed significantly less solubility in lactic acid solutions than chemical-cured glass ionomer cements.

Diethyl 1-chloro-2-phenyl-2-(tosyl) aminoethylphosphonate 의 결정 및 분자구조

김대영,이재혁,신준철,김문집 순천향대학교 기초과학연구소 1997 순천향자연과학연구 논문집 Vol.3 No.1

The crystal and molecular structure of diethyl 1-chloro-2-phenyl-2-(tosyl)aminoethyl phosphonate has been determined from single crystal X-ray diffraction study ; C19H25NO5PCIS, Monoclinic, P2₁/a, a=10.8507(11)Å, b=16.1201(12)Å, c=12.7354(12)Å, β=90.192(7)°, V=2227.6(3)ų, T=293(2)K, Z=4, Cuk α(λ=1.54178Å). The structure was solved by direct method and refined by full-matrix least squares to a final R=5.17% for 2444 unique observed F0> 4σ(F0) reflections and 254 parameters.

김치의 N-Nitrosamine오염

김수현,오창경,오명철,송대진,Hotkchiss, J.H. 濟州大學校 産業技術硏究所 1999 산업기술연구소논문집 Vol.10 No.1

Changes in N-nitrosamines during Kimchi fermentation were investigated. Thirteen unknown N-nitrosamines were detected during Kimchi fermentation, but N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) were not. Most of these N-nitrosamines were originated from chinese cabbage and some of from fermented anchovy sauce. The content of N-nitrosamines decreased remarkably at the initial stage of fermentation, but increased slightly at the final stage.

窒素施用量에 따른 콩의 收量 및 種實成分의 變化

金鍾喆,鄭大守 東亞大學校 大學院 1997 大學院論文集 Vol.22 No.-

The effects of nitrogen treatment on the yield and seed components of soybean(Glycin max (L.) Merrill), Bokwangkong and Muhankong were estimated. Increasing the amount of nitrogen, stem length, the numbers of branches, main stem node, and pod were respectively increased. Hundred grain weight and yield showed the highest value in the plot treated with 4g/10a of nitrogen. The composition rate of protein showed the highest value at the plt treatd with 4kg/10a of nitrogen, and oil components was respectively high at the plot treated with 2kg/10a of nitrogen for Bokwangkong and at the plot treated with 4kg/10a of nitrogen for Muhankong. Amino acid was generally high at the plot treated with 4kg/10a of nitrogen, and there were no correlation between the variation of mineral contents and nitrogen treatment.

개량형 치과용 시멘트의 용해도 및 피막도에 관한 비교연구

김철위,김종배,백대일,이용근 대한치과기재학회 1987 대한치과재료학회지 Vol.14 No.1

The purpose of this study was to evaluate the solubility, disintegration and film thickness of twenty-five commercially available cements-zinc phosphate (AD, AS, DH, FZ, GCB, HC, HZ, LZ, LMZ, SC and TZ), polycarboxylate (DA, DR, GCC, HPC, LC, PF, SCB, and SU) and glass jonomer (HB and OS) cements used in Korea. These tests were performed according to the modified methods of KDA Specification No. 1, 2, ISO 1566, 4104, and ANSI/ADA Specification No. 8, 61. The following results were obtained: 1. The solubility of the glass ionomer cements was higher than that of the zinc phosphate and the polycarboxylate cements. 2. The film thickness of the zinc phosphate cements was slightly higher than that of the polycarboxylate and the glass ionomer cements. 3. The solubility and the disintegration of the glass ionomer cements showed considerable differences according to the products.

감사인의 양적 중요성 판단 기준의 적용에 관한 연구

金大根,趙徹衍 韓日經商學會 2001 韓日經商論集 Vol.21 No.-

This thesis studied if, under the varied audit environment, there is any significant difference on the degree of strictness (rigidity) of an auditor's quantitative materiality judgement when an auditor formulates audit opinion regarding to the exception out of gathered evidence. This study defined the degree of strictness as : the lower the average of threshold between unqualified and qualified opinion, the stronger the degree of strictness of an auditor's quantitative materiality judgment. This research found the followings: First, there is no statistically significant difference in the degree of strictness of an auditor's quantitative materiality judgment affected by the scale of the auditor. Second, the scale of the client affects an auditor in the degree of strictness of an auditor's quantitative materiality judgment. Third, there is a significant difference in the degree of strictness of an auditor's quantitative materiality judgment for listed vs. non-listed corporation. Fourth, the higher the debt ratio of the client, the stronger the degree of strictness of an auditor's quantitative materiality judgment. Fifth, an auditor applied quantitative materiality judgment more strictly for the client corporation with any turnover between net profit and net loss.

상아질 표면처리제 및 결합제가 레진강화형 글라스 아이오노머와 상아질의 전단결합강도에 주는 영향

김용대,이용근,임범순,김철위 대한치과기재학회 2000 대한치과재료학회지 Vol.27 No.4

Resin-modified glass ionomers (RmGIs) have been widely used and are recommended for restoring cervical lesions that include enamel and dentin margins, and for caries-prone patients because of the possible anticariogenic effect of fluroride. The purpose of this study was to evaluate the shear bond strength of two resin-modified glass ionomers to dentin using four different dentin surface treatments and two one-bottle bonding agents. Human dentin was pretreated with 35 % phosphoric acid, 10 % citric acid and 3 % ferric chloride, 10 % polyacrylic acid and EDTA 3-2 solution, and was applied with One-Step and Single Bond. Two resin-modified glass-ionomers, Fuji Ⅱ LC(FLC) and Vitremer (VTM), were then adhered to the dentin. After 24 h in distilled water at 37 ℃ the shear bond strength between the resin-modified glass-ionomers and the pretreated dentin was measured with an Instron at a crosshead speed of 0.5 mm/min and the dentin-dentin bonding agent-RmGI interface of the specimen was observed by SEM. From the experiment, the following results were obtained : 1.For the dentin treated only with surface treatments except EDTA 3-2 solution, the shear bond strength of resin-modified glass ionomers to dentin was statistically significant higher than that of resin-modified glass ionomers to dentin treated with dentin surface treatments (p<0.05). 2.For the dentin applied with dentin bonding agents subsequent to pretreatment with dentin surface treatments, the shear bond strength of resin-modified glass ionomers to dentin was statistically significant higher than that of resin-modified glass ionomers to dentin treated only with dentin surface treatments (p<0.05). 3.When the specimens were applied with One-Step or Single Bond subsequent to four different dentin surface treatments, the shear bond strength of resin-modified glass ionomers to dentin was not statistically different between One-Step and Single Bond (p<0.05). 4.With applications of dentin bonding agent, 35 % phosphoric acid or 10 % citric acid + 3 % ferric chloride solutions were found to be the most effective in improving bond strength to dentin, followed by 0.5 M EDTA 3-2 solution and 10 % polyacrylic acid solution. 5.From SEM observations, 10 % polyacrylic acid solution did not completely remove the smear layers, but 35 % phosphoric acid, 10 % citric acid + 3 % ferric chloride, and 0.5 M EDTA 3-2 solution completely removed the smear layers so that could form resin tag.

인공망막칩과 형상기억합금을 이용한 평활 안구운동시스템 구현

김원철,김현수,박종호,박대식,이민호,신장규 한국뇌학회 2001 한국뇌학회지 Vol.1 No.2

본 논문에서는 인간의 평활 추적안구운동을 모방하는 능동시각시스템(active vision system)을 구현하였다. 평활 추적 안구운동을 모방하는 능동시각시스템을 구현하기 위해 인간의 안구운동 중에 관찰되는 신경생리학적인 특징들을 이해하고, 다양한 안구운동 중에서 평활 추적안구운동 중에 관찰되는 중측관자(medial temporal) 세포의 역할을 자기조직화 형상지도(self-organizing feature map)와 승자독점(winner take all)을 이용하여 구현하였다. 회전속도계 궤환 모델(tachometer feedback model)로 중상측관자(medial superior temporal) 세포의 역할을 모델하였다. 그리고 인공망막칩으로 인공 안구를 구성하고 형상기억합금 구동기(actuator)를 이용하여 인공 안근육을 구성하여, 빛의 밝기 변화인 윤곽(edge) 정보에 반응하는 인공 안구모형을 제작하였으며, 실험을 통하여 시스템의 동작성능을 보였다. In this paper, we proposed a model of smooth pursuit eye movement, and developed a human-like active vision system using a retina chip and a shape memory alloy actuator. The model of smooth pursuit eye movement is to imitate the role of MT and MST area of human brain in smooth pursuit eye movements. We fabricated the 8×8 retina chip for the edge detection. The developed retina chip is an image sensor to extract edge information and the shape memory alloy actuator is a driver to imitate the role of eye muscles to follow a moving object.