• 방사성폐기물학회지
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• 제5권2호
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• pp.145-154
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• 2007

벤토나이트 완충재의 열수거동 실험에서는 고준위폐기물처분장 완충재로 유력하게 고려되고 있는 국산 벤토나이트를 대상으로 열수특성을 규명하고, 또 그 결과를 바탕으로 KRS 처분환경에서 벤토나이트 완충재의 장기건전성을 평가하였다. 실험결과, 벤토나이트 완충재의 열수반응은 주 구성광물인 스멕타이트의 일라이트화를 통해 진행되었으며, 온도, $K^+$농도, pH는 이러한 일라이트화에 중요한 열수반응인자 역할을 하였다. KRS 처분환경에 대한 국산벤토나이트 완충재의 장기건전성을 분석한 결과, 정상상태에서는 벤토나이트 완충재가 오랜 기간 동안 방벽재기능을 유지하였지만, 보수적인 조건에서는 약 $5{\times}10^4$년이 경과했을 때 벤토나이트 완충재를 구성하는 스멕타이트의 50%이상이 일라이트로 전환되어 방벽재로서의 팽윤능력을 상실할 수 있음을 예상할 수 있었다.

• Earthquakes and Structures
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• 제5권5호
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• pp.499-526
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• 2013

Seismic isolation is an effective method for the protection of buildings and their contents during strong earthquakes. This research work aims to assess the appropriateness of the linear and nonlinear models that can be used in the analysis of typical low-rise base isolated steel buildings, taking into account the inherent nonlinearities of the isolation system as well as the potential nonlinearities of the superstructure in case of strong ground motions. The accuracy of the linearization of the isolator properties according to Eurocode 8 is evaluated comparatively with the corresponding response that can be obtained through the nonlinear hysteretic Bouc-Wen constitutive model. The suitability of the linearized model in the determination of the size of the required seismic gap is assessed, under various earthquake intensities, considering relevant methods that are provided by building codes. Furthermore, the validity of the common assumption of elastic behavior for the superstructure is explored and the alteration of the structural response due to the inelastic deformations of the superstructure as a consequence of potential collision to the restraining moat wall is studied. The usage of a nonlinear model for the isolation system is found to be necessary in order to achieve a sufficiently accurate assessment of the structural response and a reliable estimation of the required width of the provided seismic gap. Moreover, the simulations reveal that the superstructure's inelasticity should be taken into account, especially if the response of the structure under high magnitude earthquakes is investigated. The consideration of the inelasticity of the superstructure is also recommended in studies of structural collision of seismically isolated structures to the surrounding moat wall, since it affects the response.

• 대한치과교정학회지
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• 제24권4호
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• pp.933-943
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• 1994

The present study was undertaken to determine the effect of tensile force on DNA and protein biosynthesis in bone cells, and to identify the cell type(s) which primarily respond to external physical force among the heterogenous bone cell populations. As a prerequisite for this study, two bone cell populations which retain fibroblastic and osteoblastic feature were isolated from fetal rat calvaria with sequential enzyme digestion scheme. Tensile force was delivered to each bone cell population by two acrylic resin plates connected with a orthodontic expansion screw during culture period. Rate of DNA and protein synthesis in each bone cell population were assessed by the incorporated radioactivity of $[^3H]-thymidine$ into DNA and $[^3H]-proline$ into fraction of collagenase-digestible protein and noncollagenous protein, respectively. DNA synthesis of osteoblast-like calvarial cell populations was increased significantly by the application of tensile force for 24 hours. In contrast, no alteration in DNA synthesis of fibroblast-like populations could be observed in response to applied force. Tensile force induced the change in protein synthesis of bone cell populations with the same pattern. Total protein and collagen synthesis were increased whithin 24 hours in osteoblast-like populations, but not in fibroblast-like populations by tensile force application. These findings indicate that physical force can affect cellullar activity of the particular cell population, not all cell Populations residing in bone and osteoblasts respond more sensitively than fibroblasts. So osteoblasts can modulate the behavior of other bone cells including osteoclasts by producing several local regulating factors of bone metabolism. In this context, preferential responsiveness of osteoblasts to applied tensile force observed in this study suggests that osteoblasts may play an important role in regulation of physical force-induced remodelling process.

• 한국초전도ㆍ저온공학회논문지
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• 제18권4호
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• pp.1-4
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• 2016

We investigated the relation between the Cu-O bond length and the superconducting properties of $BaSnO_3$ (BSO)-added $GdBa_2Cu_3O_{7-x}$ (GdBCO) thin films by using extended x-ray absorption fine structure (EXAFS) spectroscopy. 4 wt.% $BaSnO_3$ (BSO) added $GdBa_2Cu_3O_{7-x}$ (GdBCO) thin films with varying thickness from $0.2{\mu}m$ to $1.0{\mu}m$ were fabricated by using pulsed laser deposition (PLD) method. The transition temperature ($T_c$) and the residual resistance ratio (RRR) of the GdBCO films increased with increasing thickness up to $0.8{\mu}m$, where the crystalline BSO has the highest peak intensity, and then decreased. This uncommon behaviors of $T_c$ and RRR are likely to be created by the addition of BSO, which may change the ordering of GdBCO atomic bonds. Analysis from the Cu K-edge EXAFS spectroscopy showed an interesting thickness dependence of ordering behavior of BSO-added GdBCO films. It is noticeable that the ordering of Cu-O bond and the transition temperature are found to show opposite behaviors in the thickness dependence. Based on these results, the growth of BSO seemingly have evident effect on the alteration of the local structure of GdBCO film.

• Asian Pacific Journal of Cancer Prevention
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• 제16권17호
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• pp.7497-7500
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• 2015

Background: Tumor markers, designated as a broad group of substances produced by malignancies, could be in the form of biochemical substances, immunological substances, cell surface changes and genetic alterations. Cancer, a disorder of cellular behavior is characterized by alteration of serum glycoproteins. L-fucose, a hexose, which is the terminal sugar in most of the plasma glycoproteins, may be useful as a tumor marker for the detection, monitoring and prognostic assessment of malignancies. The aim of the study was to ascertain the role of serum fucose as a biomarker for early detection of oral cancer and to compare serum fucose levels in healthy controls, leukoplakia and oral cancer patients. Materials and Methods: The study included 60 (100.0%) subjects, who were grouped as 20 (33.3%) control subjects, 20 (33.3%) squamous cell carcinoma patients and 20 (33.3%) leukoplakia patients. Fucose estimation was done using UV-visible spectrophotometry based on the method as adopted by Winzler using cysteine reagent. The results were analyzed statistically using ANOVA with Bonferroni post hoc tests. Results: Results showed a high significance in serum fucose in oral squamous cell carcinoma (OSCC) and leukoplakia subjects compared to normal controls. There was a gradual increase in the values noted from control to leukoplakia and to squamous cell carcinoma. Conclusions: Estimation of serum fucose may be a reliable marker and can be used as an effective diagnostic biomarker in oral squamous cell carcinoma patients.

• 한국습지학회지
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• 제14권2호
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• pp.289-301
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• 2012

조석의 영향에 의해 해수의 유 출입이 용이한 해수호수를 친수 친환경으로 조성하는 계획이 인천 송도에서 수행되었다. 본 연구는 조석의 영향을 받는 해수호수의 수리동역학적 거동을 분석하기 위해서 1차원 수치모형인 CEA모형과 2차원 수치모형인 FLOW2DH를 이용하여 수로의 폭에 따라서 변화하는 해수호수 내의 수위 및 유속을 계산하였다. 연구 결과, CEA모형을 이용하여 수로의 적정 폭은 100.0m로 선정되었고, 외해 조위와 인공호수 수위의 지체시간과 수로 내 최대 유속이 계산하였다. 이 결과를 FLOW2DH와 연동하여 해수호수 내의 수위 및 유속을 각각 선정된 관측점에 대하여 비교 분석하였다. 또한, 인공호수의 유지관리 측면에서 수문이 설치된 경우에 대하여 수치모형 실험을 추가하여 수문이 설치되지 않은 경우보다 유속이 창조 시 약 20%, 낙조 시 약 50% 감소하는 효과를 얻었다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.169-174
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• 1999

The reclamation area of Saemangeum (Kunsan) located between 126$^{\circ}$10' -126$^{\circ}$50'E and and 35$^{\circ}$35'N -36$^{\circ}$05'N at the western coast of Korea. The construction of the 33km sea dike is building in the Saemangeum area. When the construction of the sea dike in the coastal region takes plase, there exists a certain amount of soil which is diffused by the tidal current. Behavior of the soil diffusion usually depends on its intrinsic characteristics, bathymetry, construction method and used mchinery. The amount of soil at the construction acts as a pollutant which is the cause of changing the marine environment. When the soil material is diffused , it may form a layer which obstructs the light passing into the sea and causes the extinction or alteration of the living beings on the sea bottom. The settlement of soil material could change the sea bottom deposit. The purpose of MITIGATION is to harmonize the development and the conservation of environment, to restrict environmental destruction and to reproduce the enviroment damaged by the construction in the coastal region. The purpose of this study is to find the method by which we minimize the anti-function of development in the coastal region. Tide and tidal current are calculated using a two-dimensional numerical model before the construction of sea dike in Saemangeum Bay. The numerical results are compared well with field observations. On the basis of these results, we caculated the tide and tidal current after the construction of the sea dike in order to investigate the change of the tide and tidal current after the construction of the sea dike. Moreover, we calculated the tide and tidal current after the construction of submerged breakwater in order to preserve the enviornmental condition of creature habitat . We compared the tide and tidal current before and after the construction of submerbed breakwater, to investigate the possbility of MITIGATION in the fisheries.

• The Korean Journal of Physiology and Pharmacology
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• 제11권3호
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• pp.113-119
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• 2007

Developmental disability shows life-long behavioral abnormality with no significant physical malformation. This study was undertaken to develop an animal model for developmental disability by using two-factor approach. Lipopolysaccharide (LPS), a bacterial toxin, and NAN-190, a $5-HT_{1A}$ receptor antagonist, were administered to Sprague-Dawley rats on postnatal day (PND) 5 to induce inflammation and an altered 5-HT system, respectively. Long-term alteration of behavior occurred in the drug-treated groups. The LPS-treated group showed impaired motor coordination in the Rota-rod test. The LPS- treated or both LPS and NAN-190-treated groups showed impaired fore-paw muscle power in the wire maneuver test. These groups also showed decreased white matter volume and increased serotonergic fibers. The LPS and NAN-190-treated group also exhibited neurologic deficit in the placing reaction test and impaired equilibrium function in the tilt table test. The results showed that a variety of altered behaviors can be generated by two factor model, and suggested that combination of important etiologic factors and possible underlying defects is a promising strategy of establishing an animal model for developmental disabilities.

• 자원환경지질
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• 제43권6호
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• pp.543-553
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• 2010

이 연구는 부여 정동리 꿩바윗골 유적에서 출토된 백제시대 경작토양의 광물학적 및 지구화학적 특정을 조사하고, 이를 사용하여 제작한 것으로 추정되는 무령왕릉 및 송산리 전(벽돌)과 토양을 비교하여 태토로서의 가능성을 검토하였다. 연구대상 토양시료들은 모두 미사질 양토로 가장 하부층을 제외하고는 모두 유사한 토양입도를 가지고 있다. 토양은 산성으로 일부 시료에서 유기물, P, S 등의 집적현상이 나타났다. 또한 지구화학적 원소 분포경향이 유사하며 석영, 사장석, 정장석, 질석, 운모, 고령석 등으로 구성되어 동일한 광물조성을 보인다. 부분적으로 붉은 철산화물의 농집이 관찰되는데, 강의 범람과 배수에 따른 산화와 환원환경이 반복되었던 환경이 토양 내 철산화물의 농집을 일으킨것으로 보인다. 이는 자연현상과 인간의 경작활동에 의한 풍화양상으로 볼 수 있다. 특히 무령왕릉과 송산리고분군 출토 전에서 발견되는 철산화물의 농집현상은 연구지역 토양이 전의 태도로 추정될 수 있는 추가적인 증거로 판단된다.

• 한국산림과학회지
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• 제78권4호
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• pp.372-380
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• 1989

주요(主要) 조림수종(造林樹種)의 하나인 현사시나무를 Agrobacterium rhizogenes의 agropine 계통(系統)인 A4를 이용(利用)하여 유전적(遺傳的)으로 형질전환(形質轉換)시켰다. 형질전환(形質轉換) 여부는 조직(組織)내의 opine(agropine) 존재를 분석(分析)하여 확인(確認)하였다. 형질전환(形質轉換)으로 얻어진 hairy root는 1/4MS+sucrose 30g/L에서 가장 좋은 생장(生長)을 보였으며, 식물체(植物體) 재분화(再分化)는 BAP 0.5mg/l를 첨가한 MS배지(培地)에 배양(培養)하였을 때 가장 좋은 결과(結果)를 얻었다. 재분화(再分化)된 식물체(植物體)는 뿌리가 많고 형태적(形態的)으로 변형(變形)되어 정상의 식물(植物)과 구별(區別)할 수 있었다. 부분적(部分的)으로 뿌리부분(部分)만 형질전환(形質轉換) 시킴으로써 보다 많은 뿌리를 가진 개체(個體)로 만들 수 있었고 이는 임목(林木)의 지상부(地下部) 형질개량(形質改良)에 유리(有利)한 것으로 나타났다.