페탄광 주변 하천의 수질조사

정경훈,최형일,정오진,정재경,강성환,조영찬 조선대학교 환경공해연구소 1998 環境公害硏究 Vol.14 No.-

The Water quality for river surrounding closed coal mine in Hwasun area Chunnam was investigated. The investigated factors were pH, turbidity, conductivity, Fe, SO_(4)^(-2), Ca, and Mg concentration, and the crystallization form and components of suspended solids were also investigated by scanning electron microscope and energy dispersion system Extremely high value of turbidity and conductivity were represented in Honam Kwangup (N-7) and Honam Tanza (N-3)area, respectively. Fe concentration was lower in all sampling sites, and the concentration of SO_(4)^(-2) ion was higher than 200mg/L in all sampling sites excepting Dongyang Tanggwang area (N-2) and Hwail wetland (N-11). The SEM micrograph and EDS analysis showed that the crystallization form of the suspended solids was formless, These particles have size of less than 10??and the main components was O, Al, Fe and S. The corelation values between conductivity and Mg, SO_(4)^(-2), and Ca were 0.967, 0.959, 0.931, respectively, and the results indicate good corelation.

소아 감염성 질환에서 경구용 Cefixime(Suprax^�)의 임상 효과에 관한 연구

정수미,오만택,최재각,김종덕 圓光大學校 醫科學硏究所 1994 圓光醫科學 Vol.10 No.1-2

The effect of cefixime was evaluated clinically from March 1 to April 30, 1994. The drug was administered orally to the 30 pediatric patients of acute pharyngo-tonsillitis, pneumonia and urinary tract infections. We compared the result with the other 30 pediatric patients of same diseases whom were administered intrave-nousely augmentin and gentamycin or augmentin and cefotaxime. The results are as follows : 1. The clinical improvements of the cefixime administered group is similar to the control group. 2. The abnormal laboratory findings, such as leukocytosis and elevated ESR and pneumonic infiltrations on chest x-ray were normalized in both groups. 3. Clinically observed cure rate of acute pharyngotonsillitis was 100%, pneumonia 84.6%, UTI 100% respectively on cefixime administered group. 4. The adverse drug reaction was noticed on cefixime administered group as follows; diarrhea were two cases and vomiting one case.

폐탄광 주변 하천의 수질조사

정경훈,최형일,정오진,정재경,강성환,조영찬 조선대학교 환경연구소 1998 環境硏究 Vol.14 No.1

The Water quality for river surrounding closed coal mine in Hwasun area Chunnam was investigated. The investigated factors were pH, turbidity, conductivity, Fe, SO_^-2, Ca, and Mg concentration, and the crystallization form and components of suspended solids were also investigated by scanning electron microscope and energy dispersion system. Extremely high value of turbidity and conductivity were represented in Honam Kwangup (N-7) and Honam Tanza (N-3)area, respectively. Fe concentration was lower in all sampling sites, and the concentration of SO_4^-2 ion was higher than 200㎎/L in all sampling sites excepting Dongyang Tanggwang area (N-2) and Hwail wetland (N-11). The SEM micrograph and EDS analysis showed that the crystallization form of the suspended solids was formless, These particles have size of less than 10㎛ and the main components was O, Al, Fe and S. The corelation values between conductivity and Mg, SO_4^-2, and Ca were 0.967, 0.959, 0.931, respectively, and the results indicate good corelation.

알루미늄의 전기분해를 이용한 인 제거

정경훈,최형일,정오진,최칠남,정재경 한국환경과학회 2000 한국환경과학회지 Vol.9 No.1

Laboratory experiments were performed to investigate the effects of various factors on the phosphorus removal by electrolysis with aluminium electrodes. The efficiency of phosphorus removal increased with increasing of voltage applied, surface area of electrodes and electrolyte concentration, and decreasing of electrode distance. The phosphorus removal was not affected by the connection number of an electric circuit. The amount of aluminium ion eluted from electrodes according to Faraday's law was 4.47 ㎎ and the Al/P mole ratio was 2.14 at the electric current value of 20 ㎃.

소아 신장질환에 대한 임상 통계적 관찰 : 11년간의 고찰 An Eleven-Years Experience

이재호,정기영,유재홍,최동석 충남대학교 의과대학 지역사회의학연구소 1989 충남의대잡지 Vol.16 No.1

Statistical analysis of renal inpatients admitted to the department of pediatric ward of Chungnam National University Hospital from 1978 to 1988 was performed according to their annual incidence of each disease, disease pattern, and age distribution. Renal diseases were found in 628(6.16%) among 10,194 total inpatients from 1978 to 1988. Male to famale ratio of renal disease was 1.99 to 1. Annual incidence of acute glomerulonephritis was decreased but no significant change was noted in the incidence of nephrotic syndrome and urinary tract infection. Acute glomerulonephritis was the leading cause of admission in all age groups and it constituted 28.82% of total renal patients. It was followed by nephronic syndrome(23.24%), urinary tract infection(16.56%). Wilms’ tumor(7.64%), Henoch-Schonlein nephritis(6.21%), and recurrent hematuria(4.45%). Urinary tract infection showed relatively high incidence in infancy and acute glomerulonephritis and nephrotic syndrome were high in older age group. Renal diseases were most frequently found in 7-9 years old age group. Chronic renal failure and recurrent hematuria were relatively frequent in over 12 years old age group.

국내 의료종사자에서 HHV-8의 항체양성률에 대한 연구

주우철,최용준,박재은,이혜명,이진수,정문현,김수미,문지혜 대한감염학회 2008 감염과 화학요법 Vol.40 No.4

HHV-8 virus is known to be associated with Kaposi's sarcoma (KS) in HIV seropositive patients and its seroprevalence has geographic difference, In South Korea, incidence of KS is low not only in general population but also in HIV patients compared to other countries, It is speculated that low seroprevalence of HHV-8 has contributed to the low incidence of KS in South Korea. We examined the seroprevalence of anti HHV-8 IgG of HIV seronegative health care workers in one University hospital. Enzyme-linked immunosorbent assay(ELISA) was used for diagnosis. One person (0.6% 1/164) was seropositive, six were equivocal (3.7%,6/164) and 157 people were seronegative (95.73%, 157/164). This study revealed that seroprevalence of HHV-8 in general population was. low in South Korea. Further studies are needed to be carried out to evaluate the low HHV-8 seroprevalence in Korea.

절삭공구 팁의 TiCN코팅 특성

황경층,윤종호,최재하,김성청 충북대학교 산업과학기술연구소 2002 산업과학기술연구 논문집 Vol.16 No.2

As the machine tool industry progresses, the performance of cutting tools also needs to be of good quality and specialized. If the existing metal cutting tool tip is coated properly, its life would be longer and the machining of a difficult-to-cut material also could be possible. For the development of the high quality cutting tool, the applicabilities of TiCN coating deposited by PVD on the cutting insert were experimentally investigated. The various analyses such as SEM micrograph, XRD pattern, AFM surface morphology, and hardness were performed to cross-check the possibility and availability of TiCN coated tool in the field.

선인장 양심실 보조장치의 설계 및 임상적용을 위한 평가

민병구,박찬영,최재순,이혁수,황창모,김삼성,윤걸중,김종원,선경,이경갑,정종태,김원곤 제주대학교 인공심장이식연구소 2001 인공심장 연구 Vol.2 No.1

현재 개발되고 있는 맥동형 이식형 인공심장은 완전이식형 인공심장과 좌심실보조장치 뿐이다. 좌심실보조장치를 장착한 환자의 10~15%가 우심실의 보조를 필요로하고 완전이식형 인공심장의 장착을 위해서는 자연심장을 제거해야하는 상황에서 이식형 양심실보조장치에 대한 필요성이 대두되고 있다. 본 연구진은 완전이식형 인공심장으로 개발된 한국형 인공심장을 개선하여 양심 실 보조장치를 개발하였다. 양심실보조장치는 이동형 작동기식 미케니즘을 이용하고 있으며 에너지 변환장치와 감속기로 구성된 작동기와 혈액주머니, 그리고 내장형 제어기로 구성되어 있다. 선인장 펌프로 명명된 KAH350은 캐뉼라의 연결을 위한 커넥터를 포함하여 길이 177mm, 폭 164mm, 높이 67 이고 무게 780g이며 최대 심박출량은 5L/min 이다. 양심실보조장치로 개발된 선인장펌프는 좌심실보조장치로도 응용이 가능하다. 이식적합성과 생체적합성을 평가하기 위하여 좌심실보조장치로 5회, 양싱실보조장치로 6회의 동물실험을 수행하였다. 각각 최장 28일간 생존하였으며 11회의 동물실험중 장치의 결함에 의한 것이 3회 있었는데 이들은 모두 전자장치의 결함과 방수처리문제였다. 현재 이식적합성과 일박출량을 향상시킨 KAH400모델이 개발중이다. The types of pulsatile implantable artificial hearts that are on the way of development and have been developed are totally implantable artificial heart and implantable left ventricular assist device (LVAD). Approximately 10% to 15% of all patients Implanted with wearable VADs have required right heart support with another device. And it is reluctant to patient who should remove his or her own heart to be implanted with total artificial heart. These situations drive the development of implantable bi-ventricular assist device (BVAD). The Korean BVAD was develophed by modifying the moving actuator type Korean artificial heart. This electro-mechanical BVAD comprises actuator including energy converter and reduction gear train, blood sacs, and internal motor and energy controllers. The KAH350 which is named as 'Cactus Pump' is 177mm in length, 164mm in width, and 67mm in thickness including connectors and nuts. The weight and maximum cardiac output of Cactus Pump is 780g and 5L/min, respectively. The Cactus Pump that was developed as BVAD could be used as LVAD by attaching compliance caps on the 2 ports of one ventricle. The animal experiments were undergone 5 times for LVAD, and 6 times for BVAD. The best records were 28 days survival in both applications. There were 3 times of device failure and they were all associated with electrical connection and hermetic sealing. The KAH400 that has improved anatomical fitting characterisitcs and stroke volume is on development.

인코넬 690 합금의 크리프거동

황경충,윤종호,최재하,김성청 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.4

Inconel 690 alloy has widely been used in power plant and high temperature facilities because it has high thermal resistance and toughness. But, we have little design data about the creep behaviors of the alloy. Therefore, in this study, an apparatus has been designed and built for conduction creep tests under constant load conditions. A series of creep tests on Inconel 690 alloy have been performed to get the basic design data and life prediction of inconel products and we have gotten the following results. First, the stress exponents decrease as the test temperatures increase. Secondly, the creep activation energy gradually decreases as the stresses becomes bigger. Thirdly, the constant of Larson-Moller parameters on this alloy is estimated about 10. And last, the fractographs at the creep rupture show both the ductile and the brittle fracture according to the creep conditions.

접합부의 비선형 거동을 고려한 강뼈대 구조물의 고등해석과 최적설계

최세휴,박문호,송재호,임청권,Choi, Se Hyu,Park, Moon Ho,Song, Jae Ho,Lim, Cheong Kweon 한국강구조학회 2003 韓國鋼構造學會 論文集 Vol.15 No.6

The advanced analysis and optimal design of semi-rigid frame were presented. Advanced analysis can predict the combined nonlinear effects of connection, geometry, and material on the behavior and strength of semi-rigid frames. The Kishi-Chen power model was used to describe the nonlinear behavior of semi-rigid connections. Geometric nonlinearity was determined using stability functions. On the other hand, material nonlinearity was determined using the Column Research Council (CRC) tangent modulus and parabolic function. The direct search method proposed by Choi and Kim was used as optimization technique. The member with the largest unit value evaluated using the LRFD interaction equation was replaced one by one with an adjacent larger member selected from the database. The objective function was assumed as the weight of steel frame, with the constraint functions accounting for load-carrying capacities, deflections. inter-story drifts, and ductility requirement. Member sizes determined by the proposed method were compared with those derived using the conventional LRFD method. 본 논문에서는 접합부의 비선형을 고려한 강뼈대 구조물의 고등해석과 최적설계를 수행하였다. 고등해석은 접합부의 비선형, 기하학적 비선형 및 재료적 비선형을 고려한다. 접합부의 비선형은 Kishi와 Chen이 제안한 3가지 매개변수를 가지는 파워모델을 사용하여 고려하였다. 기하학적 비선형은 안정함수를 사용하여 고려하였으며, 재료적 비선형은 CRC 접선 탄성계수와 포물선 함수를 사용함으로서 고려하였다. 최적화 기법으로는 Choi와 Kim이 제안한 직접탐색법을 사용하였다. 직접탐색법은 LRFD의 상관방정식으로 계산된 값중에서 최대값을 가지는 부재의 크기를 단계별로 증가시키는 방법이다. 목적함수는 구조물의 중량을 사용하였으며, 제약조건식은 구조시스템의 하중-저항능력, 처짐, 층간 수평변위 및 연성요구 조건을 고려하였다. 제안된 방법에 의한 설계결과를 LRFD방법과 비교하였다.