사면의 안정도 해석을 위한 입체투영법

이성대,이철우,이동우,이성규 公州大學校 基礎科學硏究所 1996 自然科學硏究 Vol.5 No.-

암반 사면의 안정성을 해석하는데 입체투영기법을 이용하였다. 안정도에 영향을 미치는 요인으로는 절리의 경사, 암석의 밀도, 내부마찰각등이 있으나, 가장 중요한 요인은 절리면의 경사이다. 이 연구에서는 암석의 점착력은 무시하고 단지 내부마찰각과 절리의 주향 및 경사만을 이용하였다. 그 결과 입체투영도에서 나타나는 암반사면의 안정도는 이동력과 저항력의 상대적인 크기에 의하여 좌우되는 것으로 나타났다. 동시에, 지반진동에 의한 영향도 입체 투영기법으로 찾아낼수 있다는 것이 밝혀졌다. Stereographic projection technique was used to analyze rock slope stability. Strike and dip of joints, rock strength, and internal frictional angle are major factor on slope stability. Among them, the most important factor is strike and dip of joints. In stereographgic projection technique, only internal frictional angle, and strike and dip of joints were used to interprete slope stability. Cohesion of rock was not considered. It is suggested that the rock slope stability on stereographic projection depends upon only the differential stress between driving and resisting force. At the same time, Stereographic projection technique on seismic loading was proposed in this study.

토양중 게르마늄 농도에 따른 벼의 생육 특성 및 게르마늄 흡수

이성태,이영한,최용조,이상대,이춘희,허종수 한국환경농학회 2005 한국환경농학회지 Vol.24 No.1

게르마늄의 약리효능이 알려짐에 따라 게르마늄이 깅화된 기능성 농산물의 요구도가 높아지는 추세이다. 본 연구는 게르마늄의 농업적 이용에 대한 기초 사료를 제공하고자 실시하였으며, 벼의 생육 및 게르마늄 흡수에 미치는 게르마늄처리 효과는 다음과 같다. 게르마늄을 0, 2.5, 5.0, 7.5 및 10.0 mg/kg으로 처리할 토양을 와그너포트에 넣어 벼를 재배힌 결과, 게르마늄 처리농도가 증가할수록 게르마늄 독성의 증가로 초장, 수장, 수수 및 수량이 급격히 감소하였으며 게르마늄 2.5 mg/kg 이상에서는 게르마늄 독성이 발생하였다. 게르마늄 처리농도가 증가할수록 벼의 게르마늄 흡수랑은 증가하였으나 벼의 게르마늄 이용율은 게르마늄 2.5, 5.0, 7.5 mg/kg 처리에서 각각 20.7, 12.5 및 7.5%로서 게르마늄 처리농도가 증가할수록 감소하였다. 벼의 부위별 게르마늄 함량은 볏짚>왕겨>현미 순으로 높았다. 게르마늄 2.5 mg/kg 처리시 볏짚, 왕겨 및 현미의 게르마늄 함량은 각각 103.4, 30.2 및 3.02 mg/kg 이었고, 볏짚과 왕겨에서는 게르마늄 무처리에서도 각각 2.9 및 3.9 mg/kg을 함유하고 있었다. 쌀의 아미노산 함량을 분석한 결과 게르마늄 처리농도가 증가할수록 Asx., Thr., Ser. 등 대부분 종류의 아미노산 함량이 증가하였으며, 그 결과 현미중 질소흡수량도 증가하였다. In order to obtain the basic information for agricultural utilization of Germanium(Ge), the growth characteristics and Ge absorption of rice plant were investigated with different Ge concentration in soil. Ge concentrations were treated with 0, 2.5, 5.0 7.5 and 10.0 mg/kg in pot(1/5,000a), respectively. As higher the Ge concentration in soil, the Ge absorption amount in straw, husk and brown rice were increased. But the yields were decreased with the increase of Ge phytotoxicity. When rice plant was grown more than 2.5 mg/kg Ge(as GeO₂) in the soil, growth was inhibited by germanium phytotoxicity and necrosis spots were observed in the rice leaf blades. Therefore the optimum concentration of Ge was less than 2.5 mg/kg in rice plant. When rice plant was cultivated on soil supplemented with 2.5 mg/kg Ge, Ge content in straw, husk and brown rice was 103.4, 30.2 and 3.02 mg/kg, respectively. The Ge content in plant was high in the order of straw > husk > brown rice. Most of the amino acids in rice were increased with the increase of Ge treatment, besides, total amino acid contents also increased.

혈액 투석 환자에서 중심정맥 협착에 대한 스텐트 삽입술 : Wallstent Placement

임대승,노상필,이유선,정승현,김보영,이정우,강정아,김정희,이민수,정준용,최시완,정진옥,성인환,이강욱,신영태 충남대학교 의과대학 의학연구소 2002 충남의대잡지 Vol.29 No.1

Stenosis of central vein is a common complication arising after percutaneous subclavian vein catheter insertion performed for temporary vascular access in chronic renal failure patients undergoing hemodialysis. There are several treatment methods for the condition like percutaneous angioplasty(PTA), stent insertion, and surgery, but recent trend is toward PTA and stents. Among the patients diagnosed with chronic renal failure from March 1993 to May 2002 and undergoing hemodialysis through AV fistula, the 14 Patients in whom central vein stenosis arose were selected for the study. A total of 28 percutaneous interventions(5 PTA and 23 stent placement) were performed, and restenosis rate and the time taken till the restenosis in de novo lesions and instant lesions were compared. All 28 cases were operated successfully. The 14 cases that received both anigioplasty and stent placement initially. (de novo lesion : 14 cases), Among the 10 cases with de novo lesion that followed up more than 1 year, 3 cases are currently undergoing hemodialysis without restenosis, and the remaining 7 cases have recurred stenosis with the mean time to restenosis of 10.9 months. In the 7 cases in whom stenosis recurred, 11 interventions were done(instent lesion: 11 cases). 4 of these were using only ballon angioplasty with 100% restenosis rate and the mean time of 3 months until restenosis. The remaining 7 cases were using both balloon angioplasty and stent placement, also with 100% restenosis rate but with the mean time of 12 months until restenosis, which was later than the group receiving only balloon angioplasty. In treating the patients with central vein stenosis, stent placement seems to be more advantageous over PTA in terms of restenosis rate and the mean duration of patency. In the case of instent lesion, inserting the stent for the second time after stenosis recurred lengthened the duration of patency compared to performing balloon angioplasty alone.

영구형 항서맥 심박조율기 환자의 장기추적관찰

최현석,이무용,최영진,최성준,김효수,손대원,오병희,이명묵,박영배,최윤식,이영우,이명용 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.5

Algal bioassay 에 의한 조류생장 제한영양염류 결정

오희목(Hee Mock Oh),이석준(Seog June Lee),김성빈(Seong Bin Kim),박미경(Mi Kyung Park),윤병대(Byung Dae Yoon),김도한(Do Han Kim) 한국하천호수학회 1998 생태와 환경 Vol.31 No.2

Determination of Limiting Nutrient for Algal Growth by Algal Bioassay. Oh, Hee-Mock, Seog June Lee, Seong-Bin Kim, Mi- Kyung Park, Byung-Dae Yoon and Do-Han Kim (Environmental Microbiology Research Unit, Korea Research Institute of Bioscience and Biotechnology, Taejon 305-333, Korea and Water Resources Research Institute, Korea Water Resources Corporation, Taejon 305-390, Korea) Water quaiity and algal growth potential (AGP) using Microcystis aeruginosa were investigated from April to September 1997 in Daechung Reservoir. Secchi disk transparency was 1.1 m in August. Chlorophyll-a concentrations were higher than 10㎍/l at all samples. Total phosphorus concentration was in a range of 0.020∼0.027mg/l which is at the approximate value of 0.03 mg/l, the general critical level of eutrophication. These results indicate that Daechung Reservoir is in an eutrophic state except some temporary times and restricted sites. Phosphorus uptake rate of M. aeruginosa was higher in the water from the epilimnion than in the hypolimnion and also higher under light condition than under dark condition. Therefore, phosphorus uptake rate appears to depend on cellular phosphorous content and light condition, a meaning of endergonic process. Phosphorus was the most frequently limiting nutrient: phosphorus was limiting algal gowth in April and May, nitrogen, phosphorus and trace elements were the limiting factors for algae in August, and trace elements in September. If a fast growing alga, M, aeruginosa, is used as a test organism for assaying AGP, in vivo fluorescence instead of dry weight can be measured for algal biomass and incubation period can be reduced from traditional 14 days to 7 days.

LaMnO₃형 페롭스카이트 산화물에서 입자상물질의 촉매연소반응

이용화,이근대,박성수,홍성수 한국환경과학회 2004 한국환경과학회지 Vol.13 No.7

We have studied the catalytic combustion of soot particulates over perovskite-type oxides prepared by malic acid method. The catalysts were modified to enhance the activity by substitution of metal into A or B site of perovskite oxide. In addition, the reaction conditions such as temperature and O₂ concentration were investigated. The partial substitution of alkali metals into A site in the LaMnO₃ catalyst, enhanced the catalytic activity in the combustion of carbon particulate and the activity was shown in the order: Cs>K>Na. For the La_(i_x)Cs_(X)MnO₃ catalysts, the catalytic activity showed the maximum value with x=0.3 but no more increase on the catalytic activity was shown with x> 0.3. For the La_(0.8)Cs_(0.2)MnO₃ catalyst, the substitution of Fe or Ni increased the ignition temperature. The ignition temperature decreased with an increase of O₂ concentration, however, no more increase in the catalytic activity was shown with O₂ concentration >0.2. The introduction of NO into reactants showed no effect on the catalytic activity.

갑상선 분화암 환자의 경과 관찰에서 수술전·후 혈청 갑상선글로불린 측정의 유용성

이성진,원종철,김하영,한정희,이은주,김상욱,류진숙,문대혁,홍석준,안일민 대한내분비학회 2000 Endocrinology and metabolism Vol.15 No.4·5

W/O 마이크로에멀젼에 의한 나노크기의 TiO₂/SiO₂ 합성에서 물/계면활성제의 몰 비(W_(0)) 영향 및 그 광분해 특성

이만식,주창식,이근대,홍성수 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.4

나노크기의 TiO₂/SiO₂입자는 음이온 계면활성제 AOT(sodium bis(2-ethylhexyl) sulfosuccinate)를 사용하여 W/O 마이크로 에멀젼에서 TTIP(titanium isopropoxide)와 TEOS(tetraethylorthosilicate)의 가수분해 반응에 의해 제조하였다. 그때 TEOS의 몰분율은 0.1이였다. 나노입자 제조시 W_(0)(H₂O/AOT)비에 따른 열적안정성, 표면적, 결정성 및 결정크기 등과 같은 물리적 특성은 TEM, XRD, BET, FT-IR, TGA-DTA 등을 사용하여 분석하였다. 또한 광촉매적 특성을 알아보기 위해 회분식 반응장치를 이용하여 p-니트로페놀의 광분해 활성을 조사하였다. 제조된 Ti0₂/SiO₂ 나노입자는 열처리 온도 105℃, 300℃에서 비결정구조를 가졌으며, 소성온도 800℃에서는 Ti0₂ 결정입자 내에 무정형의 SiO₂로 인해 열적 안정성이 증가되었고, 여전히 anatase 결정을 유지하였다. 그리고 Ti0₂/SiO₂(90/10) 입자에서 SiO₂ 결정은 관찰되지 않았다. 제조된 촉매는 대체로 구형이며 아주 균일한 분포를 갖는 것으로 관찰되었다. W_(0) 비가 증가할수록 결정크기는 증가되었고, 표면적은 감소하는 경향을 나타내었다. 또한 p-니트로페놀에 대한 광분해 활성은 순수한 Ti0₂ 보다 Ti0₂/SiO₂(90/10) 촉매가 우수하였다. Nanosized TiO₂/SiO₂ particles were prepared by hydrolysis of TTIP (titanium isopropoxide) and TEOT (tetra-ethylorthosilicate) in sodium bis (₂-ethylhexyl)sulfosuccinate (AOT) reverse micelles. The mole fraction of TEOS was 0.1. The physical properties, such as surface area. thermal stability, crystallite size and crystallinity according to W_(0), ratio have been investigated by TEM, XRD, BET, FT-IR, TGA and DTA. In addition. the photocatalytic degradation of p-nitrophenol has been studied by using batch reactor in order to compare the photocatalytic activity of prepared nanosized TiO₂/SiO₂, particles. It is shown that the XRD pattern of the particle heat treated at 105℃ and 300℃ indicates amorphous and the major phase of all the prepared particles were anatase structure. No significant rutile phase was observed although the calcination temperature at 800℃ and no peaks SiO₂ crystal were also observed for TiO₂/SiO₂ (90/10). The presence of amorphous SiO₂ in TiO₂/SiO₂ particle enhanced the thermal stability of TiOz particle resulting in the suppression of the phase transformation from anatase to rutile phase. The crystallite size of prepared particles decreased with decreasing W_(0) ratio. The surface area increased with decreasing W_(0) ratio. In addition, TiO₂/SiO₂ (90/10) particles shows higher photoactivity than that of pure TiO₂ particles.

만성 간질환에 대한 DDB(Biphenyl Dimethyl Dicaboxylate)의 임상적 효과

이헌영,임의혁,김성걸,김진희,육은주,성자원,김병호,정형용,강대영,김영건 충남대학교 의과대학 지역사회의학연구소 1994 충남의대잡지 Vol.21 No.2

To investigate the effects of short-term administration of DDB(Biphenyl Dimethyl Dicarboxylate) for decreasing elevated serum aminotransferase levels in chronic liver diseases, authors applied 3 capsules of DDB per day at each meal time for 35 patients and compared with 35 patients treated with other conservative management. The following results were obtained. 1. Serum alanine aminotransferase (ALT) levels significantly decreased from 247.1± 180.0 IU/L of pretreatment level to 96.6±126.0 IU/L, 61.1±62.7 IU/L and 38.0±26.8 IU/L after 1, 3 and 6 months of treatment(p<0.05) and effective rates were observed in 60.0%, 71.4% and 88.6% of patients after 1, 3 and 6 months of treatment. 2. Serum aspartate aminotransferase (AST) levels decreased also significantly from 167.8±96.9 IU/L of pretreatment levels to 124.4±155.0 IU/L, 77.9±49.6 IU/L, 60.6± 46.9 IU/L after 1, 3 and 6 months of treatment(p<0.05), but decreasing pattern of serum AST was less significant than that of serum ALT. 3. No significant difference were observed in the serum ALT and AST changes according to the cause and duration of hepatitis. 4. No significant adverse effects were observed in whole patients treated with DDB. It is suggested that small dose administration of DDB is effective for decreasing serum aminotrans ferase levels in chronic liver disease in which other conservative management was not effective.

Junctional Rhythm을 보인 한국형 출혈열 1례

이성원,이수훈,최대현,손영기,차광수,손춘희,정원태,김성은,김종성 동아대학교의과대학 1997 동아의대학술지 Vol.9 No.1