화학적 처리에 의한 1 차 하수처리장의 처리효과 개선 : 현장시험을 중심으로

곽종운,김승현,이찬원 대한상하수도학회 1997 상하수도학회지 Vol.11 No.1

슬라브의 연속주조시 냉각에 대한 수학적 모델

고창호,현종각,백영현 고려대학교 공학기술연구소 1986 고려대학교 생산기술연구소 생기연논문집 Vol.22 No.1

A mathematical model describing heat transfer in the continuous casting of slab is proposed. The model consists of a unidimensional transient conduction equation arid boundary condition equations which specify heat flux at the metal-mold interface. The proposed model is characterized by followings: 1) the length of the mush (liquid-solid) region was estimated by experimental data and 2) the internal heat generation term was introduced to the main heat balance equation. By using FDM, cooling of slab was simulated at various casting conditions, and surface temperature as well as the locations of liquidus and solidus were determined as a function of casting distance. The results thus obtained revealed that the model fits better for the measured temperature profile.

리튬 2 차 전지의 양극재료인 스피넬 망간산화물의 용해와 용량감소

오승모,이종화,홍진규,장동훈 한국공업화학회 2001 공업화학 Vol.12 No.2

대장 선종과 Apolipoprotein E 유전형과의 관계

김영호,최윤호,손희정,강태욱,최규완,최봉준,이종철,박상종,이지민,배문희,김재준,이풍렬 대한소화기내시경학회 2001 Clinical Endoscopy Vol.23 No.1

Background/Aims: Apolipoprotein B polymorphism plays an important role in the metabolism of cholesterol. And bile acids, which may be related to the development of colorectal adenomas, An association between apolipoprotein B genotype and colonic adenomas bas been reparted in a western country. This study was designed to determine whether the apolipopratein S was genotype would be associated with proximal or distal colonic adenomas in Koreans. Methods: On the colonoscopy, colonic adenomas were found in 132 patients. Proxima1 colonic adenoma was found in 35 patients and distal colonic adenoma was found in 97 patients. Serum leveis of total cholesterol, LDL-cholesterol, HDL-cholesterol and trlglyceride were measured. Apolipoprotein E genotype was determined by PCR and allele specific oligonucleotide hybridization. 279 contro1 subjects without an adenoma on the screening sigmoidoscopy were se1ecfed randomly. Results: The serum levels of total choles0'rol, LDL-cholesterol, HDL-cholesterol and triglyceride did not significantiy differ between each adenoma group and control group. The individual frequencies of ε2, ε3 and ε4 alleles in patients with colonic adenomas did not differ from those in control subjects. The frequency of either heterozygote or homozygote for g 4 allele in patients with proximal adenoma was lower than that in control subjects (0.029 vs O.I68, p $lt; 0.05). Conclnsions: The data suggest that g 4 allele may be associated with a lower risk for the development of proximal colonic adenoma in Korean men.

췌장암에서 Cyclooxygenase - 2 발현의 역할

김은경,이용욱,이규택,최규완,박동일,백승운,이준행,이종균,고광철,이풍렬,이종철,김재준,김완선,공구 대한소화기학회 2001 대한소화기학회지 Vol.38 No.3

Background/Aims: Accumulating evidence suggests that the use of NSAID may reduce the incidence of colorectal cancer. The likely mechanisms of these effects by NSAID is cyclooxygenase-2 (COX-2)-related inhibition of tumor proliferation and induction of apoptosis. The aim of our study was to examine possible roles and clinical significance of COX-2 expression in pancreatic cancer. Methods: Seventy-two pancreatic adenocarcinoma tissue specimens were obtained from surgical resection. After the immunohistochemical staining of the specimens, we examined proliferation activity (assayed by Ki-67 expression), apoptosis (by TUNEL stain), and microvessel density (by CD34 expression). We also investigated the relationship between the immunohistochemical expression of COX-2 and various clinicopathological characteristics. Results: The COX-2 positive rate in pancreatic epithelial cells was 41.7%. Proliferation index (PI) was significant higher in COX-2 positive specimens comparing to negative specimen (p=0.015) and the increase in intensity of COX-2 expression correlated with increasing PI (p=0.036). Apoptotic index (AI) was significantly higher in positivee COX-2 expression than in negative expression (p=0.044), but there was no significant difference in AI/PI between the COX-2 positive and negative specimens (p=0.44). The expression of COX-2 protein did not correlate with microvessel density, sex, age, differentiation, tumor size, stage, metastasis or patients survival. Conclusions: The expression of COX-2 enzyme in pancreatic cancer contributes to tumor proliferation, but is not related to apoptosis, angiogenesis or clinical characteristics. Further study is needed to examine the clinical usefulness of NSAID and COX-2 selective inhibitors.

간세포암과 주위 조직에서의 Transforming Growth Factor-beta 1과 그 수용체의 발현

최규완,백승운,최문석,김소정,이준혁,고광철,이풍렬,이종철,박상종,안병훈,김재준 대한소화기학회 2001 대한소화기학회지 Vol.37 No.4

Background/Aims: Transforming growth factor-beta 1 (TGF-β1) is a potent inhibitor of hepatocyte proliferation and its receptor is known to be involved in the carcinogenesis. This study was designed to compare the expression levels of the TGF-β1 and its receptor in neoplastic cells and its surrounding tissue and to assess their role in hepatic carcinogenesis. Methods: We measured the levels of TGF-β1 mRNA and TGF-β1 receptor II mRNA by semiquantitive RT-PCR for the tumor and its surrounding tissue of 30 patients with hepatocellular carcinoma (HCC). We analyzed the relationship between the expression of TGF-β1 mRNA, TGF-β1 receptor II mRNA and clinicopathological characteristics of HCC. Results: The expression of TGF-β1 mRNA showed no difference between HCC and its surrounding tissue, but the expression of TGF-β1 receptor II mRNA was lower in HCC than in its surrounding tissue (2.47±1.08 vs 3.53±1.50, p=0.00). There was no difference in the expression level of TGF-β1 mRNA and TGF-β1 receptor II mRNAo the clinicopathological characteristics of HCC. However, the ratio of TGF-β1 receptor II mRNA in HCC to that in surrounding tissue was more decreased in HCC with portal vein invasion (0.49±0.22 vs 0.77±0.21, p=0.01). Conclusions: Our data suggest that the loss of TGF-β1 receptor II may play an important role in carcinogenesis and tumor progression of HCC.

주철에서(鑄鐵)의 흑연구상화(黑鉛球狀化) 기구에 관한 연구

홍종휘 고려대학교 공학기술연구소 1971 고려대학교 생산기술연구소 연구보고 Vol.2 No.2

The mechanism of spheroidizing of graphite during melting was studied by analyizing distribution of nodulizing elements. The nodule formation of the graphite may be due to the adsorption on the graphite surface, or to the nucleation of graphite by some compounds of nodulizing elements during melting. To eliminate the problems as many composition variables as possible, the samples used in these experiments consisted simply of pure iron and charcoal with pure nodulizing element. Nodular graphite was produced by the addition of Mg, Ca, Ce, Bi and Zr, in the critical concentration and analyzed retained nodulizing elements in graphite, interface between graphite and matrix and matrix by X-ray micro-analyzer. The results were as follows. (1) The spheroidizing of graphite in Mg-treated cast iron seemed to be due to the adsorption of nodulizing element on graphite surface and nucleation of graphite both. (2) The spheroidizing of graphite in Ca, Ce-treated cast iron respectively seemed to be due to the adsorption of nodulizing element nn the graphite surface. (3) The spheroidizing of graphite in Zr, Bi-treated cast iron respectively seemed to be due to the nucleation of graphite by some compounds of nodulizing elements.

신장이식에 대한 마취경험

김종래,박광원,문영삼,정인석,손영은 대한마취과학회 1982 Korean Journal of Anesthesiology Vol.15 No.1

질소/인 동시제거를 위한 하수의 화학적 처리 : 소규모 파일럿실험을 중심으로

곽종운,최정환 한국수처리기술연구회 1994 한국수처리학회지 Vol.2 No.3

The main purpose of this paper is to illustrate how the chemical sewage treatment has been influenced on the removal of nitrogen and phosphorus from the municipal sewage water. A pilot system adjacent to a sewage treatment plant was designed to evaluate the efficacy in removing nitrogen and phosphorus. The chemical treatment step for this system included flocculation and sedimentation. In the test period of about four weeks, the pilot plant for chemical/biological treatment using a coagulant of prepolmerized Hi-PAX was operated in comparison with the conventional biological treatment. The appropriate dosage was 33 ㎕/ℓ to all tested process and the corresponding flow rate of sewage water to be treated was 500 ℓ/day. In our study, phosphorus was possible to remove up to 79% from 4.23 ppm of raw sewage water due to the precipitation with aluminium component from the coagulant used. Chemical precipitation had a positive effect on the denitrification because of a lower carbon to nitrogen ratio. In order to enhance denitrification rate, acetic acid as single carbon source was added to the reaction zone at equivalent rates, showing about 93% in the removal of nitrogen.

성인에서 반복적인 위장관출혈로 발현한 공장 거대 중복성 낭종

김영호,이경수,이상수,문원,강태욱,최규완,박동일,도재혁,백승운,이풍렬,이종철,김재준,류민규 대한내과학회 2001 대한내과학회지 Vol.61 No.3

Duplication of the alimentary tract is an unusual congenital anomaly which may occur at any level, from the oral cavity to the rectum. Jejunal duplication cyst is quite rare and most of them are presented in infancy with the symptoms of abdominal mass, obstruction, hemorrhage and perforation. But some cases has not been diagnosed till adult if duplication cyst was too small enough to cause symptoms. We report a case of a 28-year-old woman who presented with recurrent gastrointestinal hemorrhage as a result of an ulceration without ectopic mucosa in jejunal duplication cyst and was successfully treated with surgery.(Korean J Med 61:264-269, 2001)