• 제목/요약/키워드: High-$T_{c}$

검색결과 4,296건 처리시간 0.034초

하계 마산만 혐기성 환경에서의 미량금속의 거동 (Behavior of trace metals in Masan Bay, Korea during oxygen deficient period)

  • 진용현;김경태;정창수;김석현;양동범;홍기훈;이광우
    • 한국해양환경ㆍ에너지학회지
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    • 제3권4호
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    • pp.56-64
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    • 2000
  • 1999년 8월, 마산만의 용존산소는 표층으로부터 저층으로 가면서 급격히 감소하는 수직분포를 보였다. 모든 정점에서 저층수중 빈산소현상이 나타났으며 무산소 상태인 정점도 있었다. 마산수로에서 표층수의 용존성 Cd, Zn은 마산만 안쪽에서 바깥쪽으로 가며 점차 감소하였고 Pb의 경우 안쪽에서부터 바깥쪽으로 가며 증가하는 경향을 보였다. 저층수중 Cd, Cu Pb, Zn의 용존성 미량금속농도는 표층수보다 대체로 낮은 농도를 보였으나 Co는 빈산소 상태이거나 혐기성 환경인 저층수와 퇴적물로부터 용출되었기 때문에 저층수에서 높은 값을 보였다. 입자성(acid-teachable fraction) Cd, Cu, Pb 그리고 Zn은 표층보다 저층에서 대체로 높은 함량을 나타냈다. 본 조사에서는 저층수의 용존산소의 포화율이 낮을수록 Cd, Cu, Pb 그리고 Zn의 K/sub d/ 값이 증가하는 경향을 보였다. 표층퇴적물에서 Cd, Cu 그리고 Zn 등 원소들은 내만 육수유입원으로부터 멀어질수록 농도가 감소하는 경향을 보였다.

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예비유아교사의 소프트웨어 교육에 대한 관심도 분석: 관심중심수용모형(CBAM)을 중심으로 (Analysis on Pre-service Early Childhood Teachers' Stage of Concerns about Software Education According to the Concerns-Based Adoption Model)

  • 정지현
    • 한국산학기술학회논문지
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    • 제18권7호
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    • pp.431-440
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    • 2017
  • 본 2018년 소프트웨어 교육 필수화를 앞두고 최근 초 중등교육현장에서는 소프트웨어 교육 운영 및 지원방안 마련에 한창이다. 이러한 시점에서 본 연구는 소프트웨어 교육의 유아교육에의 도입가능성을 전제로 예비유아교사의 소프트웨어 교육에 대한 관심도를 조사하였다. 이를 위해 B광역시 소재 4년제 대학교 예비유아교사 132명을 대상으로 관심중심수용모형(CBAM)에 따른 설문을 실시하였다. 수집된 자료는 원점수 평균을 도출한 후 간이 채점표를 적용하여 상대적 강도로 전환하고 이를 관심도 프로파일 그래프로 나타내었으며, 배경변인에 따른 관심도 차이를 알아보기 위해 독립 t-test와 ANOVA를 실시하였다. 연구결과, 예비유아교사의 소프트웨어 교육에 대한 관심도는 0단계(지각)가 95%로 가장 높고, 정보적, 개인적, 운영적 관심이 높은 수준으로 나타나 대체적으로 비사용자 패턴을 나타내었다. 그러나 전형적 비사용자 패턴에 비해 개인적, 정보적 관심도가 다소 높고 6단계(재초점)로의 '꼬리 올리기'현상이 나타남으로써 어느 정도 비판적 비사용자에 가까운 패턴 양상을 띠기도 하였다. 필요성 인식, 향후 실행계획 유무, 테크놀로지 효능감 수준에 따라 운영을 제외한 모든 단계에서 유의미한 수준의 관심도 차이를 나타내었고 교육 및 연수경험에 따른 차이에서는 6단계(재초점)에서만 유의미한 차이를 나타내었다. 이러한 결과를 바탕으로 향후 유아 소프트웨어교육의 도입을 앞두고 새로운 테크놀로지 활용에 대한 예비교사의 개방적인 인식전환이 요구되는 가운데, 코딩교육 등으로 대변되는 사교육 기반의 유아소프트웨어 교육이 아닌, 유아의 발달수준에 적합할 뿐만 아니라 누리과정과 연계된 교육활동으로서의 가치를 확인시켜줄 수 있는 유아 소프트웨어 교육을 위한 교사 교육의 필요성이 제안되었다.

유치원 교사의 소프트웨어 교육에 대한 관심도 분석: 관심중심수용모형(CBAM)을 중심으로 (Analysis on Kindergarten Teachers' Stage of Concerns about Software Education: An Application of the Concerns-Based Adoption Model(CBAM))

  • 박선미;정지현;강민정
    • 한국산학기술학회논문지
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    • 제19권2호
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    • pp.462-471
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    • 2018
  • 올해부터 시행되는 소프트웨어 교육의 초 중 고등교육에의 정규 교육과정 편성을 앞두고 유아를 대상으로 한 소프트웨어 교육에 대한 관심 역시 높아지고 있다. 이러한 시점에서 본 연구는 유치원 교사의 소프트웨어 교육에 대한 관심도를 관심중심수용모형(CBAM)을 통해 알아봄으로써 유아 소프트웨어교육의 도입을 위한 유아교사교육 방안에의 시사점을 얻고자 하였다. 이를 위해 B광역시 소재 유치원에 재직하고 있는 교사 219명을 대상으로 설문을 실시하였다. 수집된 자료는 간이 채점표를 적용하여 상대적 강도로 전환하고 이를 관심도 프로파일 그래프로 나타내었고 배경변인에 따른 관심도 차이를 알아보기 위해 독립 t 검증을 실시하였다. 연구결과, 유치원 교사의 소프트웨어 교육에 대한 관심도는 0단계(지각)가 가장 높고, 운영적, 개인적, 정보적 관심 순으로 높은 수준으로 나타나 대체적으로 비사용자 패턴을 띄었으나 전형적 비사용자 패턴에 비해 비판적 비사용자에 가까운 패턴을 나타내었다. 필요성 인식에 따른 소프트웨어교육에 대한 관심도에 차이를 분석한 결과 모든 단계에서 통계적으로 유의한 차이를 보였고, 교육 및 연수 경험에 따른 소프트웨어 교육에 대한 관심도 차이를 분석한 결과는 0단계(지각)에서만, 그리고 향후 실행 계획 유무에 따른 소프트웨어 교육에 대한 관심도 차이를 분석한 결과는 0단계(지각), 6단계(재초점)에서 통계적으로 유의한 차이를 보였다. 프로파일 그래프 형태는 전체 평균에 의한 패턴과 비교적 유사한 비사용자 형태를 유지하였다. 이러한 결과를 바탕으로 유아교사의 소프트웨어 교육에 대한 관심도 패턴을 전환시키고 소프트웨어 교육역량을 증진시키기 위한 방안이 제안되었다.

난소 낭종이 체외수정시술을 위한 과배란유도 주기에 미치는 영향에 관한 연구 (The Effects of Ovarian Cysts on the Controlled Ovarian Hyperstimulation Cycles for In Vitro Fertilization and Embryo Transfer Program)

  • 황태영;김석현;신창재;김정구;문신용;이진용;장윤석
    • Clinical and Experimental Reproductive Medicine
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    • 제16권2호
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    • pp.205-210
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    • 1989
  • To investigate the effects of ovarian cysts on the controlled ovarian hyper-stimulation cycles, 16 patients with 16 paired cycles for IVF-ET were analyzed. These patients had taken both type of cycles, i.e., with cyst(cyst group) and without cyst(control group). Mean diameter of ovarian cysts in cyst group was 18.2mm. There were no significant differences in hormone levels in early follicular phase between two groups. No significant differences were found in total dosage of hMG(IU) administered during the ovarian stimulation $843.8{\pm}123.0$ vs $891.0{\pm}129.8$, serum estradiol level (pg/ml) on the day of hCG administration($1542.8{\pm}1100.6$ vs $1567.5{\pm}1193.0$), the number of aspirated follicles $10.0{\pm}3.4$ vs $11.2{\pm}4.3$ and oocytes $5.3{\pm}3.3$ vs $6.2{\pm}3.1$, the fertilization rate(51.2 % vs 57.2 %) and the cleavage rate(40.5 % vs 52.0 %). Serum estradiol terminal patterns during COH in one group tended to be repeated in the other group. In conclusion, this study suggests that small ovarian cysts do not adversely impact on the controlled ovarian hyperstimulation parameters in IVF - ET program and the presence of small ovarian cyst without concomitant high basal serum estradiol level is not an indication of the cancellation of the controlled ovarian hyperstimulation for IVF-ET.

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성선자극호르몬이 흰쥐 난소의 GnRH와 GnRH mRNA의 발현에 미치는 영향 (Effect of Gonadotropin on the Expression of GnRH and GnRH mRNA in Rat Ovary)

  • 백원영;정파진;박신근;김완영;이종학;김종화;김명옥;최완성
    • Clinical and Experimental Reproductive Medicine
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    • 제21권1호
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    • pp.121-130
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    • 1994
  • Expression of gonadotropin releasing hormone(GnRH) has been described in the rat ovary. It remains, however, unkown whether GnRH is synthesized as a prohormone. Therefore, this study was performed to verify the expression of pro-GnRH by in situ hybridization and further to investigate the effect of gonadotropin on GnRH or GnRH mRNA in rat ovary by immunohistochemical and in situ hybridization techniques. Adult female Sprague-Dawely rats were used and the estrous cycle was synchronized by intraperitoneal injection of pregnant mare's serum gonadotropin(PMSG). Ovaries were fixed with 4% paraformaldehyde and embedded with G.C.T. compound and cut by cryostat. For immunohistochemistry, avidin-biotin peroxidase complex(ABS) method was employed and for in situ hybridization, $^{35}S$-end labeled oligonucleotide was used and followed by autoradiography. By in situ hybridization using GnRH oligomer and GAP(GnRH associated protein) oligomer, GnRH mRNA and GAP mRNA were co-localized in the fullicular cells, luteal cells, interstitial cells and theca cells. GnRH or GnRH mRNA signals in the ovary increased by human chorionic gonadotropin(hCG) injection. At the 3 and 6 hrs after hCG injection, the number of GnRH and GnRH mRNA containing cells increased rapidly and the density of GnRH and GnRH mRHA culminated at 9 hrs after heG injection. With the follicular development, the high expression of GnRH and GnRH mRNA was also observed within the follicles. After ovulation, the density of GnRH or GnRH mRNA decreased in the follicles but increased in the corpus lutea.

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Lack of Influence of an XRCC3 Gene Polymorphism on Oral Cancer Susceptibility: Meta-analysis

  • Zhang, En-Jiao;Cui, Zhi-Gang;Xu, Zhong-Fei;Duan, Wei-Yi;Huang, Shao-Hui;Tan, Xue-Xin;Yin, Zhi-Hua;Sun, Chang-Fu;Lu, Li
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권23호
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    • pp.10329-10334
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    • 2015
  • Background: To systematically summarize the association between the X-ray repair cross complementing 3 (XRCC3) gene polymorphism and oral cancer susceptibility by meta-analysis. Materials and Methods: Databases including PubMed, EMbase, CNKI, VIP and WanFang Data were searched to identify case-control studies concerning the association between an XRCC3 gene polymorphism and the risk of oral cancer from the inception to June 2014. Two reviewers independently screened the literature according to the criteria, extracted the data and assessed the quality. Then meta-analysis was performed using Stata 11.0 software. Results: Seven published case-control studies including 775 patients with oral cancer and 1922 controls were selected. Associations between the rs861539 polymorphism and overall oral cancer risk were not statistically significant in all kinds of comparison models (CT vs CC: OR=0.94, 95%CI=0.74-1.18; TT vs CC: OR=0.94, 95%CI=0.64-1.38; dominant model: OR=0.95, 95%CI=0.76-1.18; recessive model: OR=0.94, 95%CI=0.69-1.29; allele T vs C: OR=0.97, 95%CI=0.84-1.11). In the stratified analysis by ethnicity, no significant associations were found among Asians and Caucasians. On stratification by tumor type, no significant associations were found for cancer and oral premalignant lesions. Conclusions: The XRCC3 gene polymorphism was not found to be associated with the risk of oral cancer. Considering the limited quality of the included case-control studies, more high quality studies with large sample size are needed to verify the above conclusion.

DLC 필름의 마찰마모 특성의 습도 의존성에 대한 연구 (Humidity Dependence of Tribological Behavior of DLC Films)

  • 박세준;이광렬;이승철;고대홍
    • 한국진공학회지
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    • 제15권3호
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    • pp.287-293
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    • 2006
  • R.F. PACVD법을 이용하여, 벤젠을 반응기체로 사용하여 순수한 DLC필름을 증착하였다. DLC필름의 마찰마모특성은 시험 환경을 제어하기 위하여 챔버로 고립된 ball-on-disk형식의 마모시험기를 이용하여 측정하였다. 상대습도에 따른 필름의 마찰특성을 관찰하기 위하여, 상압에서 챔버 내의 습도를 0-90%로 조절하면서 관찰하였다. 그리고 상대면 물질의 영향을 알아보기 위하여 스틸볼과 함께 DLC필름이 코팅된 스틸볼을 사용하였다. 스틸볼을 사용시 습도가 0%에서 90%로 증가함에 따라 마찰계수가 0.025에서 0.2로 크게 증가하였다. Ferich debris가 생성되지 않는 DLC가 코팅된 볼을 사용하여 실험한 경우에, 마찰계수는 상대 습도가 90%인 경우에도 0.08정도로, 스틸볼을 사용하였을 경우보다 훨씬 더 낮은 습도의존성을 보여주었다. 스틸볼 사용시 나타나는 DLC필름의 마찰계수의 큰 습도의존성은 습도가 증가함에 따라 debris의 크기 증가와 함께 스틸볼의 마모로 인한 Fe-rich debris의 생성과 밀접한 관계가 있음을 확인 할 수 있었다. 그리고 스틸볼을 사용하여 90%의 습도에서 마모시험을 하는 중간에 습도를 0%로 변화시키며 관찰한 결과, 마찰계수 값이 급격히 감소하였다. 이와 같은 결과를 통하여, Fe-rich debris가 마찰계수에 미치는 영향은 debris내의 Fe원소가 습도에 매우 민감한 흑연상의 전이층을 형성시킨다는 것을 확인 할 수 있었다.

재배 지대에 따른 참당귀의 추대 변이와 FLC 유전자 특성 (Variation of Bolting at Cultivation of Different Regions and Molecular Characterization of FLC homologs in Angelica gigas Nakai)

  • 김영국;여준환;안태진;한신희;안영섭;박충범;장윤희;김정국
    • 한국약용작물학회지
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    • 제20권5호
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    • pp.359-364
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    • 2012
  • This study were carried out to find bolting response of cultivation in different regions and to isolate FLC (FLOWERING LOCUS C) homologs in Angelica gigas Nakai. The mean temperature of different regions, ordering in altitude, were as follows: 100 m > 350 m > 530 m > 700 m. The largest amount of rainfall was occurred in the region of 350 m while the longest time of sunshine was occurred in the region of 100 m. The content of soil chemical properties in regions showed pH 6.2 ~ 7.4, T-N 0.17 ~ 26, organic mater $1{\sim}32gkg^{-1}$, $P_2O_5$ ${151{\sim}664_{mgkg}}^{-1}$, exchangeable potassium and calcium and magnesium were 0.78 ~ 1.15, 3.9 ~ 10.0, ${0.7{\sim}3.2_{cmol}}^{+kg-1}$. L5 line of A. gigas was occurred in bolting at all regions, but the bolting ratio was 60.0% in 700 m region with non-mulching treatment. Manchu of A. gigas was not occurred in bolting at all regions. The accumulation bolting ratio of L5 line by non-mulching was higher than that of mulching as 90.4% and 72.8% in 100 m region. The MADS-box transcription factor FLC is one of the well-known examples as a strong floral repressor. We decided to isolate FLC homologs from A. gigas as a starting point of flowering mechanism research of this plant. We have isolated two RT-PCR products which showed very high amino acid sequence homology to Arabidopsis FLC.

Effects of Tiam 1 on Invasive Capacity of Gastric Cancer Cells in vitro and Underlying Mechanisms

  • Zhu, Jin-Ming;Yu, Pei-Wu
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권1호
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    • pp.201-208
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    • 2013
  • Objective: To investigate changes in the invasive capacity of gastric cancer cells in vitro after expression inhibition of T lymphoma invasion and metastasis inducing factor 1 (Tiam 1) and underlying mechanisms. Methods: Using adhesion selection, two subpopulations with high ($M_H$) or low ($M_L$) invasive capacity were separated from the human gastric cancer cell line MKN-45 ($M_0$). Tiam 1 antisense oligodeoxynucleotide (ASODN) was transfected into $M_H$ cells with liposomes, and expression of Tiam 1 mRNA and protein was determined by RT-PCR and quantitative cellular-ELISA. Changes in the cytoskeleton, invasive capacity in vitro and expression of ras-related $C_3$ botulinum toxin substrate 1 (Rac 1), integrin ${\beta}1$ and matrix metalloproteinase 2 (MMP 2) between Tiam 1 ASODN transfected $M_H$ cells and non-transfected cells were observed by HE staining, cytoskeletal protein staining, scanning electron microscopy, Boyden chamber tests and cyto-immunohistochemistry. Results: A positive correlation existed between the expression level of Tiam l mRNA or protein and the invasion capacity of gastric cancer cells. After ASODN treatment ($0.43{\mu}M$ for 48 h), Tiam 1 mRNA transcription and protein expression in $M_H$ cells were decreased by 80% and 24% respectively (P < 0.05), compared with untreated controls, while invasive capacity in vitro was suppressed by 60% (P < 0.05). Morphologic and ultrastructural observation also showed that ASODN-treated $M_H$ cells exhibited smooth surfaces with obviously reduced filopodia and microspikes, which resembled $M_0$ and $M_L$ cells. Additionally, cytoskeletal distribution dramatically altered from disorder to regularity with reduced long filament-like structure, projections, pseudopodia on cell surface, and with decreased acitn-bodies in cytoplasm. After Tiam 1 ASODN treatment, the expression of Rac 1 and Integrin ${\beta}1$ in $M_H$ cells was not affected (P > 0.05), but that of MMP 2 in $M_H$ cells was significantly inhibited compared with untreated cells (P < 0.05). Conclusion: Over-expression of Tiam-1 contributes to the invasive phenotype of gastric cancer cells. Inhibition of Tiam 1 expression could impair the invasive capacity of gastric cancer cells through modulating reconstruction of the cytoskeleton and regulating expression of MMP 2.

Validating the Structural Behavior and Response of Burj Khalifa: Synopsis of the Full Scale Structural Health Monitoring Programs

  • Abdelrazaq, Ahmad
    • 국제초고층학회논문집
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    • 제1권1호
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    • pp.37-51
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    • 2012
  • New generation of tall and complex buildings systems are now introduced that are reflective of the latest development in materials, design, sustainability, construction, and IT technologies. While the complexity in design is being overcome by the availability and advances in structural analysis tools and readily advanced software, the design of these buildings are still reliant on minimum code requirements that yet to be validated in full scale. The involvement of the author in the design and construction planning of Burj Khalifa since its inception until its completion prompted the author to conceptually develop an extensive survey and real-time structural health monitoring program to validate all the fundamental assumptions mad for the design and construction planning of the tower. The Burj Khalifa Project is the tallest structure ever built by man; the tower is 828 meters tall and comprises of 162 floors above grade and 3 basement levels. Early integration of aerodynamic shaping and wind engineering played a major role in the architectural massing and design of this multi-use tower, where mitigating and taming the dynamic wind effects was one of the most important design criteria established at the onset of the project design. Understanding the structural and foundation system behaviors of the tower are the key fundamental drivers for the development and execution of a state-of-the-art survey and structural health monitoring (SHM) programs. Therefore, the focus of this paper is to discuss the execution of the survey and real-time structural health monitoring programs to confirm the structural behavioral response of the tower during construction stage and during its service life; the monitoring programs included 1) monitoring the tower's foundation system, 2) monitoring the foundation settlement, 3) measuring the strains of the tower vertical elements, 4) measuring the wall and column vertical shortening due to elastic, shrinkage and creep effects, 5) measuring the lateral displacement of the tower under its own gravity loads (including asymmetrical effects) resulting from immediate elastic and long term creep effects, 6) measuring the building lateral movements and dynamic characteristic in real time during construction, 7) measuring the building displacements, accelerations, dynamic characteristics, and structural behavior in real time under building permanent conditions, 8) and monitoring the Pinnacle dynamic behavior and fatigue characteristics. This extensive SHM program has resulted in extensive insight into the structural response of the tower, allowed control the construction process, allowed for the evaluation of the structural response in effective and immediate manner and it allowed for immediate correlation between the measured and the predicted behavior. The survey and SHM programs developed for Burj Khalifa will with no doubt pioneer the use of new survey techniques and the execution of new SHM program concepts as part of the fundamental design of building structures. Moreover, this survey and SHM programs will be benchmarked as a model for the development of future generation of SHM programs for all critical and essential facilities, however, but with much improved devices and technologies, which are now being considered by the author for another tall and complex building development, that is presently under construction.