비보강 조적벽체 전단내력산정에 관한 연구

이봉근,이정한,이원호,오상훈,나정민 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

In Korea, more than four hundred earthquakes with medium intensity centered on off-coastal and inland of Korea during the past 20 years and due to the great earthquakes which occurred recently in neighboring countries the importance of the future earthquake preparedness measures in Korea is highly recognized. More than 80 percents of residential buildings are constructed with unreinforced masonry structure, in Seoul. In general, unreinforced masonry structure don't have enough strength against the lateral force. And low rise buildings such as unreinforced masonry structure didn't adopted seismic design. So, a huge damage is expected when an earthquake occurs. It is that the major variables of shear strength are the aspect ratio, the vertical strength and the method of masonry. The objectives of this study are, 1) to find out the shear behavior of masonry wall and the variables affect the shear capacity of masonry wall such as aspect ratio of the unreinforced masonry wall, and the vertical strength, 2) to propose the equation of the shear capacity of masonry wall by regression analysis using the test data.

공기재생용 고온건식탈황제의 가압유동층 반응기에서의 사이클 성능실험

조성호,이봉희,이중범,류청걸,진경태,이창근 한국화학공학회 2002 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.40 No.2

고온고압 기포유동층 반응기에서 분무건조기로 성형제조한 아연계 탈황제(ZAC C)에 대하여 총 6회 황화-재생 반복실험을 500℃, 5atm 조건에서 수행하였다. 1% H_2S를 포함한 석탄모사가스를 반응기에 주입하여 황화반응을 시킨 결과 배출가스 중 H_2S 농도는 10ppmv 이하로 유지되었다. ZAC C의 황흡수력은 6회 황화반응 동안 각각 11.1, 10.9, 11.1, 11.1, 10.9, 10.5g S/100g sorbent으로 유지되어 초기 황흡수력을 유지하였다. 공기를 이용한 500℃ 재생반응에서 배출되는 SO_2의 최대농도는 양론적으로 이론값과 일치하였다. 재생반응에서 탈황제 층의 온도는 발열반응에 의해 500℃에서 최대 750℃까지 상승하였다. 연속 70시간 동안 유동층 반응기내에서 실시된 ZAC C 탈황제의 비산되어 유출된 양은 1.07%이고, 실험 후 탈황제의 크기와 조직특성의 변화도 적었다. 고온고압반응기 multi-cyclone 실험결과 ZAC C 탈황제는 이론 황흡수력의 50% 이상을 유지하였고, 공기를 사용한 500℃의 재생반응이 원활하고 완전히 이루어졌고, 황산염생성과 같은 부반응이 없었다. Two desulfurization-regeneration experiments for a spray-dried zinc-based sorbent(ZAC C) were performed at 500℃ and 5 atm in a fluidized-bed reactor(ID 0.097㎜) facility. The H_S concentration after each desulfurization run was maintained below 10 ppmv from a simulated coal gas of 1% H_2S. The estimated sulfur absorption capacities of ZAC C sorbent were 11.1, 10.9, 11.1, 11.1, 10.9, 10.5 g S/100g sorbent, and the sorption capacity of sorbent was maintained in spite of six times sorption experiments. The maximum SO_2 concentration in regeneration effluent gas agreed with a stoichiometric value of 500℃(ca. 14vol%). In regeneration run, the peak temperature of sorbent bed in the reactor reached up to 750 due to the vigorous exothermicity of regeneration reaction with neat air. While entrainment rate for 70h continuous run in fluidized-bed reactor is 1.07%, the size and the textural properties of ZAC C sorbent also show a little change. Multi-cycle tests in fluidized-bed show that ZAC C sorbent maintains over 50% of its theoretical sorption capacity during 70h run and regeneration reaction undergoes smoothly and completely without side reactions such as sulfate formation.

고온건식탈황 유동층 반응기에서 아연계 탈황제의 재생반응에 미치는 산소농도의 영향

조성호,이봉희,진경태,이창근 한국화학공학회 2001 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.39 No.6

Zinc titanate 탈황제를 사용하여 내경 4.5㎝인 소형유동층 반응기에서 재생반응특성을 연구하였다. 산소농도를 5%에서 21%까지 변화시키면서 재생실험을 수행하였다. 산소의 농도변화에 따라 배출되는 SO_2의 최대농도는 양론적으로 이론치와 일치하였다. 발열반응으로 인한 재생반응기의 온도상승은 산소농도가 증가함에 따라 증가하였다. 2차 황화반응 초기에 SO_2가 발생되지 않는 것으로 보아 sulfate가 형성되지 않았다는 것을 확인할 수 있었다. 재생반응 후 시료의 물리-화학적 특성 분석결과 zinc titanate 탈황제는 부반응 및 물성변화가 없는 것으로 판단할 수 있었다. 이와 같은 실험으로 분무 건조법으로 성형된 zinc titanate 탈황제는 유동층 반응기에서 산소농도 21%의 공기로 재생 가능성을 보여 주었다. The regeneration characteristics of spray-dried zinc titanate sorbent in a fluidized bed reactor were examined at temperatures of 650℃ and 700℃ with the regenerated gas of the oxygen concentrations from 5% to 21%. The outlet SO_2 peak concentrations were coincided with the theoretical values depending on inlet O_2 concentration. As the oxygen concentration was increased, the temperature rise in the regeneration reactor was increased due to the heat of exothermic reaction. During the initial stage of the second sulfidation reaction, SO_2 was not detected in the outlet gases. It was an indirect indication that zinc sulfate had not been formed during the first regeneration reaction. The various analysis results showed little differences in physical and chemical properties between fresh and regenerated sorbent.

공업계고등학교 '공작기계 Ⅰ' CAD수업에서 JigsawⅡ 협동학습이 학업성취도에 미치는 효과

이세계,이상봉,금영충 한국직업능력개발원 2004 직업능력개발연구 Vol.7 No.1

이 연구는 공업계고등학교 '공작기계 Ⅰ' CAD수업에서 JigsawⅡ 협동학습이 학생들의 학업성취도에 미치는 효과를 알아보는 데 그 목적이 있다. 실험은 '정적집단 비교 설계' 를 실험 모형으로 적용하여 실험 집단은 JigsawⅡ 협동학습 집단으로, 통제 집단은 전통적 수업방법을 시행하는 집단으로 구성하였다. 실험결과를 통해 CAD수업에서 JigsawⅡ 협동학습은 학업성취도를 향상하는 데 전통적 수업방법보다 효과가 없는 것으로 나타났다. 그 원인은 이 연구의 CAD수업 내용이 기초적인 내용이었고, 또 대상 학생들이 공업계고등학교에 입학한 1학년 학생들로 CAD수업에 대한 내용을 처음으로 공부하게 되어 수업 내용에 대한 이해가 충실하지 못했기 때문인 것으로 판단된다. 따라서 학생들이 처음으로 접하게 되는 수업내용이나 기초적인 수업 내용에 대한 JigsawⅡ 협동학습 관련연구를 시행하고자 할 때에는 수업에 대한 준비가 더 필요할 것으로 판단된다. 특히 공업계고등학교에서는 학생들의 기본 학습 능력의 부족, 학업에 대한 흥미 저하, 재학생의 중도탈락증가 등의 여러 가지 문제들이 나타나고 있는데, 학교 현장에 종사하는 교사들은 이러한 문제를 해결하기 위해서 학생들이 학업에 흥미를 갖도록 다양한 교수학습 방법을 구안 후 적용해야 할 것이다. The purpose of this study was to verify the effects of JigsawⅡ cooperative learning on academic achievement of Computer Aided Design(CAD) instruction, the Machine Tool Ⅰsubject of technical high school. To verify the hypotheses of this study, 2 parts(16 students in each part) of the first grades from technical high school in Cheong-Ju were selected. Each part was divided into three sub-groups by the level of entering behavior levels. Static-Group Comparison Design was applied for experimental planning. The content of the experiment was the CAD instruction in the Machine Tool Ⅰ textbook. The experimental group was taught using a JigsawⅡ cooperative learning method and the control group using a traditional teaching method. The independent variable was teaching method and the dependent variable was academic achievement. The data was analysed using a t-test with a significance level of 0.05 Significance level established prior to data treatment. The result of this study were as follows; First, the JigsawⅡ cooperative learning in CAD instruction had little effect on the academic achievement Second, the JigsawⅡ cooperative learning in CAD instruction had little effect on the academic achievement in the entering behavior levels. Finally, the JigsawⅡ cooperative learning in CAD instruction had little effect on the academic achievement in the cognitive and functional domain of the brain.

소 수정란의 공배양 및 동결이 체외발생에 미치는 영향에 관한 연구

이종진,이명헌,남윤이,이만휘,이봉구,김상근 충남대학교 수의과대학 동물의과학연구소 1996 動物醫科學硏究誌 Vol.4 No.-

The studies on the carried out to investigate the effects of co-culture with cumulus cells and oviduct epithelial cells on the in vitro fertilization and cleavage rate of bovine follicular oocytes, and to determine the optimum thawing temperature and equilibration time of frozen bovine embryos and on survival rate and in vitro developmental rate of bovine embryos. The ovaries were obtained from slaughtered Korean native cows. The follicular oocytes were cultured in TCM-199 medium containing 10 IU/㎖의 PMSG(Sigma, USA), 10 IU/㎖의 hCG, 1 ㎍/㎖의 β-estradiol(Sigma, USA) and 10% FCS(Sigma, USA) for 24-48 hrs in incubator with 5% CO_2 in air at 38.5℃ and then matured oocytes were again cultured for 12-18 hrs with motile capacitated sperm by preincubation of heparin. The bovine embryos following dehydration by cryoprotective agents and a various concentrations of sucrose were directly plunged into liquid nitrogen and thawed in 30℃ water. The results are summarized as followes : 1. The in vitro fertilization and in vitro developmental rates of bovine oocytes co-cultured with cumulus cells in TCM-199 media were 75.0%-76.8% and 17.3%-27.6%, respectively. And in-vitro fertilization rates of cumulus-enclosed oocytes(55.4%) were significantly(p<0.05) higher than cumulus-denuded oocytes(23.1%). 2. The in vitro fertilization and in vitro developmental rates of bovine oocytes co-cultured with 1 ×10^4 cells/㎖, 1 ×10^6 cells/㎖, 1 ×10^8 cells/㎖ and 1 ×10^15 cells/㎖ oviduct epithelial cells in TCM-199 media were 74.5%-77.8% and 15.7%-21.2%, respectively. 3. The in-vitro fertilization and in vitro developmental rates of bovine oocytes co-cultured in TCM-199 media containing PMSG, hCG, PMSG + hCG, PMSG + β-estradiol, hCG + β-estradiol 0 to 40 hrs after insemination were 74.0%-77.4% and 18.9% - 23.1, respectively. 4. The survival rates of bovine embryos thawed after rapid freezing in the media containing various kinds of cryoprotective agents added 0.25M and 0.50M sucrose were 14.7% - 35.1% and 17.6% - 31.6%, respectively. The survival rates of bovine embryos thawed after rapid freezing in the freezing media containing a various concentration of sucrose added 1.5M and 2.0M glycerol, 1.5M and 2.0M DMSO, and 1.5M and 2.0M propanediol were 23.5% -31.4% and 20.6% - 34.1%, respectively. 5. The temperature thawed at 30℃ after rapid freezing of bovine embryos resulted in a significantly higher embryos survival rate than did at 20℃ and 35℃. 6. The equilibration time on the survival rates of bovine embryos was attained after short period of time(2.5-5 min.) in the freezing medium higher than ling period of time(10-20min.).

Alkalic to tholeiitic magmatism near a mid-ocean ridge: petrogenesis of the KR1 Seamount Trail adjacent to the Australian-Antarctic Ridge

Yi, Sang-Bong,Lee, Mi Jung,Park, Sung-Hyun,Han, Seunghee,Yang, Yun Seok,Choi, Hakkyum,Baek, Jongmin 극지연구소 2022 극지연구소 초록집 Vol.- No.-

Triassic mafic/intermediate paired magmatism associated with continental collision in the Gyeonggi Massif, South Korea

Sang-Bong Yi,Chang-Whan Oh,Seon Gyu Choi,Taesung Kim,Seung Yeol Lee,Keewook Yi 대한지질학회 2014 대한지질학회 학술대회 Vol.2014 No.10

Early Paleozoic metamorphism in the Mountaineer Range of northern Victoria Land, Antarctica

Sang-Bong Yi,Mi Jung Lee,Seunghee Han 대한지질학회 2019 대한지질학회 학술대회 Vol.2019 No.10

Triassic mafic and intermediate magmatism associated with continental collision between the North and South China Cratons in the Korean Peninsula

Yi, Sang-Bong,Oh, Chang Whan,Lee, Seung-Yeol,Choi, Seon-Gyu,Kim, Taesung,Yi, Keewook Elsevier 2016 Lithos Vol.246 No.-

<P><B>Abstract</B></P> <P>Triassic coeval mafic and intermediate magmatism occurred in the area suggested to be the southern margin of the North China Craton (NCC) in the Gyeonggi Massif (GM) of the Korean Peninsula. This study investigates aspects of the mafic and intermediate magmatism using SHRIMP zircon ages and whole-rock chemical and isotopic Sr–Nd data. The mafic and intermediate rocks intruded into a basement paragneiss in three areas (Yangpyeong, Odesan and Yangyang) within the GM at ca. 230Ma. The paragneiss was metamorphosed in both the Paleoproterozoic and Triassic. Gabbros (hornblende gabbro and pyroxene–mica gabbro) from the study areas exhibit strong light REE (LREE) enrichment relative to chondrite (La<SUB>N</SUB>/Yb<SUB>N</SUB> =11.1–30.6) and a high LILE/HFSE pattern, Ta–Nb–P–Ti troughs and positive Ba–K–Pb–Sr spikes on the N-MORB-normalized multi-element variation diagram. These features are typical characteristics of arc-related gabbros. The gabbros also show strongly enriched initial isotopic compositions (<SUP>87</SUP>Sr/<SUP>86</SUP>Sr<SUB>(i)</SUB> =0.7100–0.7137; ε<SUB>Nd</SUB>(t)=−13.1 to −19.7). The coeval intermediate intrusive rocks also exhibit whole-rock chemical and isotopic features (<SUP>87</SUP>Sr/<SUP>86</SUP>Sr<SUB>(i)</SUB> =0.7099–0.7143; ε<SUB>Nd</SUB>(t)=−10.8 to −18.6) similar to those of the gabbros. The mafic and intermediate intrusive rocks plot in the within-plate and/or post-collisional fields on tectonic discrimination diagrams. These data indicate that the mafic and intermediate magmatism in the study areas occurred during the Triassic post-collisional relaxation period via partial melting of sub-continental lithospheric mantle (SCLM) that was enriched in a subduction environment prior to (or during) the Permo-Triassic continental collision between the NCC and the South China Craton (SCC). The highly enriched mantle signatures revealed by the gabbros from the study areas are matched to the enriched features identified in Cretaceous mafic igneous rocks (ca. 130Ma) on the southern margin of the NCC. Thus, this study suggests that the lithospheric mantle beneath the Yangpyeong, Odesan and Yangyang areas are comparable to the SCLM of the NCC southern margin. The highly enriched nature of mafic and intermediate rocks from the study areas indicates that their source is the SCLM that was metasomatized by Permian to early Triassic subduction–continental collision processes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Mafic and intermediate magmatism may have occurred during post-collisional setting. </LI> <LI> The magma source of these rocks appears to be the enriched sub-continental lithospheric mantle (SCLM). </LI> <LI> This lithospheric mantle is comparable to the SCLM of the southern margin of the North China Craton. </LI> </UL> </P>

Timing and Metamorphic Evolution of the Ross Orogeny in and around the Mountaineer Range, Northern Victoria Land, Antarctica

Yi, Sang-Bong,Lee, Mi Jung,Lee, Jong Ik,Kim, Hwayoung 극지연구소 2021 극지연구소 초록집 Vol.- No.-