강부재 T이음의 인장파괴 매커니즘

이승용,최진규 韓國交通大學校 2013 한국교통대학교 논문집 Vol.48 No.-

When a steel bridge is connected, usually friction type joint is used for high strength bolted joints. However, sometimes tension type joint is better than friction type joint. Though, it is partially applied on building structures, and is not possible to apply it on the civil structures, because of design specification absence and lack of research data about high strength bolt tension type joints. On the other hand, the various researches are conducted in the foreign countries to apply high strength bolt on the civil structures, and tension type joints are using for the civil structures based on the researches. Therefore, this study is to suggest basic data for investigation of high strength bolt tension type joint's fundamental mechanical behaviour through the static tensile test about T connection of steel members that focus on the short bolt type of high strength bolt tension type joint. The influences about the bolt diameter differences on the same flange thickness were examined. The plastic deformation is sharply increased through the flange buckling, when bolts procure enough diameter. Also, it was possible to find little weight changes in plastic section due to the bolts diameter differences, but the influences were insufficient. On the other hand, different yield load on bolts through the failure mode was recognized even the same bolts were used when influences on the flanges with different thickness and same diameter of bolts were examined.

팔라디움 복합막의 제조 및 응용

남승은,이규호 한국공업화학회 2002 공업화학 Vol.13 No.3

팔라디움(Pd)계 막들은 수소에 대한 선택투과도가 매우 높아서 고온의 혼합 기체 중에서 고순도 수소기체의 분리에 효과적으로 이용되고 있으며 탈수소 반응 등과 연계되어 많은 연구가 이루어져왔다. 순수한 팔라디움 금속 막의 경우 수소를 투과하면 수소농도에 따라 α 상 이외에 β 상이 형성되어 격자 평창에 의한 뒤틀림 현상이 발생하여 부스러지기 쉬우며 이를 보완하기 위해 니켈, 구리, 은 등 다른 금속과의 합금이 반드시 요구된다. 또한 높은 수소투과 속도와 기계적 강도를 함께 유지하기 위해 복합막 형태의 팔라디움 막이 제조되며 복합막 제조시 박막의 핀홀을 최소화하고 장기적 안정성을 유지하는 것이 매우 중요한 문제이다. 이러한 팔라디움 막을 막반응기에 활용함으로써 탈수소 반응이나 수증기 개질 반응 등의 반응효율을 크게 높일 수 있다. 본고에서는 팔라디움 막의 구조 및 수소와 다른 기체투과 메카니즘, 여러 팔라디움 복합막 제조 방법 및 이에 따른 특성 그리고 이들의 응용분야에 대해 살펴보고자 한다. Palladium(Pd) and palladium alloy membranes, which are well-known nonporous membranes with high perm-slectivity of hydrogen, have been used to separate hydrogen of high purity from vatious gas mixtures. The study of these membrane systems as hydrogen separation membranes and membrane reactors has been rather extensive for the past several decades. Pd alloys with other metals such as nickel, copper and silver are preferred over pure Pd, since pure Pd is subject to the α-β phase transformation due to the adsorption of hydrogen, which changes the atom spacing in the metal lattice and becomes brittle after repeated cycles of hydrogen sorption and desorption. For high flux of hydrogen permeation together with mechanical stability, Pd membranes have been mostly composite type structure with thin coating layer over a memchanically strong porous supporting layer. Minimization of pin holes and maintenance of long term stability of thin coating layer are very important factors in the preparation of composit membranes. The reaction effeciency of de-hydrogenation and water vapor reforming reaction was improve by the membrane reactors made with these palladium membranes. In this paper the structure of palladium membranes, the transport mechanism of hydrogen and gases, the preparation and characteristics of various composite palladium membranes and their applications will be discussed.

자동 안개 채취기 개발

이승규,김일환 강원대학교 산업기술연구소 2000 産業技術硏究 Vol.20 No.B

In this paper, we present a development of automatic fog water collector that operates during fog events. This collector consists of fraction collectors, a wind hall and a fog sensor. When a fog event is begin, then the fog sensor would judge whether it is a fog or not. If a fog is detected, the fog would be gathered by air suction fans, At the same time, the wind direction, the wind velocity. We are also developing a wireless communication system for the remote control and data analysis to collect, store and process data collected in the automatic fog water collector.

디메틸설폭사이드에서의 고분자량 아크릴로니트릴 중합체 및 공중합체의 합성과 그의 섬유에로의 응용

유승운,박환만,이수,문규열 國立 昌原大學校 基礎科學硏究所 1993 基礎科學硏究所論文集 Vol.4 No.-

To obtain polyacrylonitrile of high molecular weight (>1,000,000) under optimum solution polymerization condition in dimethylsufoxide, which has very low chain transfer constant, using an azobisisobutyronitrile as initiator, we examined the effect of water content in reaction mixture, and the concentration of monomer and initiator on the conversion rate and polymer properties. As a result, homo PAN with Mw=1,330,000 and about 12% of conversion was prepared under the condition of[AN]=7 mole/1 and[AIBN]=6.0x10-4 mole/1 at 50℃. Copolymers with AN and other vinylic monomers such as methyl acrylate, itaconic acid, and acrylamide, having considerably high molecular weight were also prepared under similar condition. These polymer solutions after direct dilution with DMSO were suitable enough to be applied to high strength fiber formation by dry-jet-wet spinning technique. Tensile strength was improved more than twice as high as that of common acrylic fiber used as apparel.

인삼투여가 체력 및 체중감량에 미치는 영향

이명복,김창규,박성순,김귀봉,이상구,김현덕 국민대학교 스포츠과학연구소 1985 스포츠科學硏究所論叢 Vol.4 No.-

The purpose of the study was to investigate and find the metabolic and strength response to the effects of Gin Seng intake on weight reduction in Wrestlers. Ten subjects experienced five to eight years fro were used for the study. They are attending at university and engaging in wrestling program. The subjects were divided into experimental and control groups. Five exeprimental group was supplemented Korean Gin Seng with the amounts of 600g for eight weeks. The pre-post test methods was conducted. The metabolic test using the Ergo-Oxyscreen (Jager co. German) were obtained during the ergometer bicycle tests. The subjects were seated on the bicycle for two minutes after two minutes resting period, and pedalled with 60rpm at the beginning with free loading for two minutes, and increased the 0.5KP load every one minute. The exercise on the bicycle was continued until the subjects were exhausted. The metabolic data such as weight, MV(minute ventilation)., BF(breathing frequency), Heart rate, Vo_2ml kg/min., and Time. were calculated automatically and printed out the data every minute. The grip and back strength tests were obtained using the dynamometer (T.KK. Japan), and leg strength(180/sec, 30/sec.), power, isometric maximal strength, and endurance were measured through Cybex-Ⅱ system. After pre-test, exprimental group was begin to intake Gin-Seng for eight weeks, and control was start to reduce their body weight. As the results of the study, conclusion to be drawn as follows; 1. There were no significant difference between before weight reduction and after weight

The Relationship between Virological Characteristics of Hepatitis C Virus ( HCV ) and Reactivity to the Regional Specific Proteins of HCV

(Seung Kew Yoon),(Young Min Park),(Byung Hoon Byun),(Si Hyun Bae),(Jin Mo Yang),(Byung Min Ahn),(Young Sok Lee),(Chang Don Lee),(Hee Sik Sun),(Boo Sung Kim) 대한내과학회 2000 The Korean Journal of Internal Medicine Vol.15 No.2

N/A Background : Although the polyproteins of hepatitis C virus(HCV) are processed and formed in nearly equimolar amounts, individual functional proteins have a discrepancy in their time of appearance following HCV infection and eliciting immune response. This study was conducted to compare the reactivity toward regional specific HCV protein in relation to virological characteristics, including HCV genotype and HCV replication. Methods : Sera from forty-five patients with chronic HCV infection were analyzed through the experiments of the recombinant immunoblot assay(RIBA-2), HCV genotyping and HCV RNA quantitation. Results : The frequencies of seropositivity to C22-3, C33C, C100-3 and 5-1-1 proteins were 91.1%, 91.1%, 64.4% and 53.3%, respectively, of all the patients, and thus the antibodies to C22-3 and C33C proteins were found more frequently (p <0.05). The antibody responses between core or NS3 proteins and NS4 proteins showed more discrepancy in the HCC group than that in the CH group, implying a possibility of oncogenic potential of core or NS3 gene in hepatocarcinogenesis. The detection rate of antibodies to C22-3 and C33C, in accordance with serum HCV RNA levels, was significantly higher in highly viremic patients than that in low viremic patients (p <0.05). Antibodies to C22-3, C33C, C100-3 and 5-1-1 were also found more frequently in patients with HCV genotype 1b, compared to those with HCV genotype 2a (p <0.05). Conclusion : These results suggest that antibody detection of HCV may depend on the virological characteristics of HCV, the levels of HCV replication and HCV genotype and, therefore, HCV RNA detection using RT-PCR technique is essential for confirmatory diagnosis for HCV infection. Furthermore, the HCV core or NS3 Protein may play important role in hepatocarcinogenesis.

Pure Signet Ring Cell Type Early Gastric Carcinoma with Extensive Lymph Node Metastases -A Case Report

Seung Kew Yoon,Sang Wook Choi,Chang Don Lee,Hee Sik Sun,Doo Ho Park,Boo Sung Kim,Mi Kyung Jee,Seok Jin Gang,Sun Moo Kim 대한내과학회 1987 The Korean Journal of Internal Medicine Vol.2 No.2

Review : The Biology of Cancer Stem Cells and Its Clinical Implication in Hepatocellular Carcinoma

( Seung Kew Yoon ) The Editorial Office of Gut and Liver 2012 Gut and Liver Vol.6 No.1

Hepatocellular carcinoma (HCC) is a highly malignant tumor with limited treatment options in its advanced state. The molecular mechanisms underlying HCC remain unclear because of the complexity of its multi-step development process. Cancer stem cells (CSCs) are defi ned as a small population of cells within a tumor that possess the capability for selfrenewal and the generation of heterogeneous lineages of cancer cells. To date, there have been two theories concerning the mechanism of carcinogenesis, i.e., the stochastic (clonal evolution) model and the hierarchical (cancer stem cell-driven) model. The concept of the CSC has been established over the past decade, and the roles of CSCs in the carcinogenic processes of various cancers, including HCC, have been emphasized. Previous experimental and clinical evidence indicated the existence of liver CSCs; however, the potential mechanistic links between liver CSCs and the development of HCC in humans are not fully understood. Although defi nitive cell surface markers for liver CSCs have not yet been found, several putative markers have been identifi ed, which allow the prospective isolation of CSCs from HCC. The identifi cation and characterization of CSCs in HCC is essential for a better understanding of tumor initiation or progression in relation to signaling pathways. These markers could be used along with clinical parameters for the prediction of chemoresistance, radioresistance, metastasis and survival and may represent potential targets for the development of new molecular therapies against HCC. This review describes the current evidence for the existence and function of liver CSCs and discuss the clinical implications of CSCs in patients demonstrating resistance to conventional anticancer therapies, as well as clinical outcomes. Such data may provide a future perspective for targeted therapy in HCC. (Gut Liver 2012;6:29-40)

Predictive Factors for Beneficial Response to Interferon-alfa Therapy in Chronic Hepatitis C

( Seung Kew Yoon ),( Sung Soo Kim ),( Young Min Park ),( Kyu Sik Shim ),( Chang Don Lee ),( Hee Sik Sun ),( Doo Ho Park ),( Boo Sung Kim ),( Wang Shick Ryu ),( Joong Myung Cho ) 대한내과학회 1995 The Korean Journal of Internal Medicine Vol.10 No.2

A Phase 3 Study Comparing Tenofovir Alafenamide (TAF) to Tenofovir Disoproxil Fumarate (TDF) in HBeAg-Negative CHB Patients at Week 96

( Seung Kew Yoon ),( Maurizia Brunetto ),( Young Suk Lim ),( Ed Gane ),( Wai Kay Seto ),( Marina Osipenko ),( Sang Hoon Ahn ),( Harry L. Janssen ),( Akash Shukla ),( Wan Long Chuang ),( Huy Trinh ),( 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: In this randomized, double blind study in HBeAg- negative patients comparing TAF to TDF, the efficacy of TAF was demonstrated to be noninferior to that of TDF at Week 48 in the proportion with HBV DNA <29 IU/mL with improved bone and renal effects. Here we present the results after two years of treatment. Methods: 425 patients were randomized to receive TAF 25 mg QD (n=285) or TDF 300 mg QD (n=140) and treated for 144 weeks.. Efficacy analyses at Week 96 included virologic (HBV DNA <29 IU/mL), and biochemical (ALT normalization) responses; key secondary safety endpoints were changes in hip and spine bone mineral density (BMD), and changes in serum creatinine and estimated GFR by Cockcroft- Gault method (eGFRCG). Serum markers of bone turnover and urine markers of renal tubular function were also assessed. Results: Baseline characteristics included: mean age 46 years, 61% males, 72% Asians, genotypes A through D (5%, 24%, 38%, 31%); 19% had HBV DNA ≥ 7 log10 IU/mL, and 21% were previously treated with nucleos(t)ides. Efficacy and safety results are summarized in the Table. At Week 96, virologic response rates were similar in the TAF and TDF groups.A greater percentage of TAF patients achieved normalization of serum ALT valuesPatients receiving TAF showed smaller declines in hip and spine BMD compared with TDF patients through Week 96. The smaller decline in eGFRCG and smaller changes in renal tubular markers observed with TAF. The rates of treatment discontinuations for adverse events (<2%) and serious adverse events were (≤11%) were similar. Conclusions: At Week 96, high rates of virologic suppression were maintained with a higher rate of ALT normalization seen in TAF patients relative to TDF and continued improved bone and renal safety with TAF compared with TDF.