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        검색결과 307

        101.
        2011.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A high-quality CIGS film with a selenization process needs to be developed for low-cost and large-scale production. In this study, we used Cu2In3, CuGa and Cu2Se sputter targets for the deposition of a precursor. The precursor deposited by sputtering was selenized in Se vapor. The precursor layer deposited by the co-sputtering of Cu2In3, CuGa and Cu2Se showed a uniform distribution of Cu, In, Ga, and Se throughout the layer with Cu, In, CuIn, CuGa and Cu2Se phases. After selenization at 550˚C for 30 min, the CIGS film showed a double-layer microstructure with a large-grained top layer and a small-grained bottom layer. In the AES depth profile, In was found to have accumulated near the surface while Cu had accumulated in the middle of the CIGS film. By adding a Cu-In-Ga interlayer between the co-sputtered precursor layer and the Mo film and adding a thin Cu2Se layer onto the co-sputtered precursor layer, large CIGS grains throughout the film were produced. However, the Cu accumulated in the middle of CIGS film in this case as well. By supplying In, Ga and Se to the CIGS film, a uniform distribution of Cu, In, Ga and Se was achieved in the middle of the CIGS film.
        4,000원
        102.
        2011.06 구독 인증기관 무료, 개인회원 유료
        Grateloupia asiatica and G. divaricata are edibile marine red algae that commonly occur on the east coast of Korea: G. asiatica occurs in sheltered locations such as estuaries or tide pools, and G. divaricata usually grows at the depth of 2~5 meters under the sea where freshwater flows. We compared growth pattern of both species in Aninjin, Gyoam, Hosan, and Sacheon in order to find suitable location for mass culture of the Grateloupia species. In case of G. asiatica, vegetative and tetrasporangial thalli were found in Gyoam and Sacheon, while gametophytic thalli were found in Aninjin. Population from Aninjin was the largest on the average length of thalli (20.6 cm) among populations studied. Population of G. divaricata in Sacheon seems to be maintained mostly with sporophytes. However, Aninjin and Hosan populations consisted of gametophytes and sporophytes in summer. Population from Hosan was the largest on the average length of thalli (19.8 cm). Based on our results, G. asiatica and G. divaricata repeat a typical triphasic life history of red algae on the east coast of Korea.
        4,000원
        103.
        2011.05 구독 인증기관·개인회원 무료
        잠자리목은 3개 아목(실잠자리아목, 잠자리아목 및 옛잠자리아목)으로 구성 되어 있다. 형태형질 및 분자마커형질에 의한 다양한 가설이 제시된 가운데 실잠자리아목 및 잠자리아목의 단계통 여부, 옛잠자리아목의 계통분류학적 위치 에 대해서 그리고 각 아목내 상과별 및 과별 관계에 대해서 다양한 연구결과 가 존재하는 실정이다. 본 연구는 잠자리목내 7개 상과, 10개 과 총 71종을 대 상으로 COI, 16S rRNA, 28S rRNA 및 EF1-α 유전자의 염기서열을 이용하 여 한반도 내 분포하는 잠자리목내 두 아목간 및 아목내 분류군간의 계통분 석을 수행하였다. 계통수 작성은 Maximum Likelihood (ML), Baysian Inference (BI), Maximum Parsimony (MP) 및 Neighbor Joining (NJ)법을 이용하였다. 그 결과, 잠자리아목은 모든 분석에서 비교적 높은 노드 수치로 (78~100) 단 계통을 형성하였다. 반면 실잠자리아목은 MP 및 NJ 분석 결과 단계통을 형 성하였으나 ML 및 BI법을 이용한 분석 결과 청실잠자리과 (Lestidae)가 잠자 리아목의 기저부에 위치함으로 실잠자리아목의 비단계통 가능성을 제시하였 으며 이러한 결과는 타 연구에서 일부 제시된 바 있다. 보다 신뢰성 있는 계 통도 확보를 위하여 TOPOLOGY TEST 수행 결과 BI법에 의해 작성된 계통 도가 상대적으로 높은 수치로 지지됨을 확인하였다 (ELW, 0.912762; BP, 0.9129; KH, 1; SH, 1; WSH, 1 및 AU, 0.9182624). 추후 보다 심도 있는 분석을 수 행함으로 진화적 관련을 잘 반영하는 계통도를 작성할 수 있을 것으로 사료 된다.
        104.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        겨울철 유휴 논토양에 헤어리베치를 재배 이용하여 바이오에너지 원료작물인 옥수수를 재배할 경우 화학비료와 제초제를 절감하고, 옥수수의 무경운 재배법을 개발하고자 수행하였다. 헤어리베치 피복 이용 옥수수 무경운 직파재배 시 재식밀도에 따른 옥수수의 간장, 경태 및 엽색도 등은 관행재배에비하여 감소하였으며, 착수고는 밀식할 경우 증가하는 경향이었다. 그 밖의 옥수수의 출사기는 헤어리베치를 피복한 처리구에서 관행재배구에 비하여 평균 3일 지연되었으며, 재식밀도가 높을수록 또는 시비량이 감소될수록 지연되었다. 한편 경작지에서 우점하는 잡초는 여뀌, 바랭이 및 피였으며, 헤어리베치 피복량 증가는 잡초 건물중을 감소시켰다. 바이오에탄올생산량은 헤어리베치를 피복한 처리구에서 관행과 비교하여58.9~89.8%까지 확보할 수 있었으며, 재식밀도가 낮거나 시비량이 적을수록 감소 정도가 크게 나타났다. 바이오에너지 작물인 옥수수를 친환경적으로 생산하는 방법 중의 하나로 헤어리베치를 피복하고 무경운 직파하여 시비량을 50% 감량하고, 재식밀도를 125,000 주 ha-1로 높이면 총 건물수량과 바이오에탄올량을 관행과 유사한 수준을 얻을 수 있을 것으로 판단되었다.
        4,000원
        105.
        2011.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Sungnyemun roofing tiles were twice disassembled for maintenance work, in 1963 and 1997, and modern tiles were applied in 1997. However, besides differing in visual appearance, the modern tiles had distinctly different physical properties. A study has been carried out on 22 different tiles, including original Sungnyemun tiles, modern tiles applied during maintenance, traditional tiles made by tile-makers, and others, to examine their physical properties, such as bending strength, frost resistance, absorption, whole-rock magnetic susceptibility, chromaticity, differential thermal analysis, and other characteristics. Since the method of making modern tiles involves compressing clay in a vacuum, modern tiles showed relatively greater bending strength and specific gravity, while Sungnyemun tiles and those made by tile-makers, in comparison, demonstrated less bending strength and specific gravity owing to their production method of 'treading,' in which clay is mixed by having someone tread upon it repeatedly. Over time, the absorption rate of the original tile used for Sungyemun gradually decreased from 21% to 14.7%; traditional tiles from tile-makers showed absorption rates of 17%, while the absorption rate of modern tiles was just 1%, which is significantly low. As for frost resistance, Sungnyemun tiles and traditional tiles from tile-makers showed cracking and exfoliation after being subjected to testing 4 or 5 times, while slight cracking was seen on the surface for modern tiles after 1ngy, or 3 times. In other words, no significant difference from influence by frost was found. According to the results of differential thermal analysis, the plastic temperature was shown to have been no less than 1, on℃ for all types of tile, and cristobalite was measuredthrough XRD analysis from a Sungnyemun female tile applied during maintenance in 1963, which appeared to have been plasticized at between 1,200℃~1,300℃. Based on these research results on the physical properties of tiles from the Sungnyemun roof, a fundamental production method for tiles to be applied in the restoration of Sungnyemun has been identified.
        5,100원
        106.
        2011.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구의 목적은 경기도 소재의 한 과학관 전시 설명에 반영된 과학의 인식론적 특징을 탐색하는 것이다. 과학의 인식론적 이해는 오랜 시간 다양한 경험을 통해 형성되는 암묵적 차원이 크기 때문에, 학교 밖의 일상 경험을 통해 학생들은 다소 안정된 과학의 이미지를 형성하게 될 가능성이 크다. 따라서 본 연구의 대상은 학교 밖 과학교육 맥락의 하나인 과학관의 전시 설명으로 정하고, Ryder 등(1999)의 인식론적 범주를 사용하여 분석하였다. 연구의 결과는 '근거와 지식주장의 관계', '과학적 탐구의 본질', '과학의 사회적 차원'의 범주로 나누어, 각 범주에 대한 인식론적 특징을 세부적으로 탐색하고 해당 범주의 전시 설명 사례를 제시하였다. 전시 설명 사례는 주로 한 범주의 인식론적 특징을 반영하는 것으로 나타났다. 하나의 근거와 하나의 지식주장을 연결하거나, 개인적 흥미 혹은 과학 학문내적 탐구를 통해 지식을 생성하는 과정을 기술하거나, 과학 공동체 혹은 기관 차원의 과학 활동을 소개하는 등이었다. 본 연구의 결과를 토대로, 과학관 전시물의 여러 매체를 활용하여 다양한 범위의 인식론적 특징을 반영할 것이 제안되었다.
        4,900원
        107.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Zinc soap and Zn/Ba mixed metal soap were synthesized and PVC plastisol with mixed metal soap and various costabilizers were also synthesized with good structures and characterized by IR and 1H-NMR. The IR spectrums and 1H-NMR spectrums of the synthesized soaps were in very good accordance with the structures proposed by earlier workers. In using phosphite as a costabilizer, TIDP phosphite was shown to be the excellent thermal stabilization effect at the low temperature and TNPP phosphite was shown to be the excellent thermal stabilization effect at the high temperature. In case of antioxidant, it was revealed that antioxidant was not effective in the low temperature thermal stabilization effect while highly effective in the high temperature thermal stability. NaClO4 solution with sorbitol solvent had the best thermal stabilization effect among NaClO4 solution series at low and high temperature.
        4,000원
        108.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 우리나라의 고층기상 관측자료와 수치모델(RDAPS 10km) 예상 자료를 활용하여 대기 불안정도와 건조도를 포함하는 산불잠재 위험지수인 Haines Index(HI)와 산불과의 관계를 분 석하였고, 그 결과 산불 확산 잠재성이 높은 HI=5, 6은 4월에 가장 높게 나타났고, 대기의 안정도 보다는 건조도가 높게 나타났으며, 산불의 발생과 확산에 큰 영향을 주는 것으로 나타났다.
        4,000원
        109.
        2010.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This study examined the effect of current density on the surface morphology and physical properties of copper plated on a polyimide (PI) film. The morphology, crystal structure, and electric characteristics of the electrodeposited copper foil were examined by scanning electron microscopy, X-ray diffraction, and a four-point probe, respectively. The surface roughness, crystal growth orientation and resistivity was controlled using current density. Large particles were observed on the surface of the copper layer electroplated onto a current density of 25 mA/cm2. However, a uniform surface and lower resistivity were obtained with a current density of 10 mA/cm2. One of the important properties of FCCL is the flexibility of the copper foil. High flexibility of FCCL was obtained at a low current density rather than a high current density. Moreover, a reasonable current density is 20 mA/cm2 considering the productivity and mechanical properties of copper foil.
        3,000원
        110.
        2010.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The selenization process has been a promising method for low-cost and large-scale production of high quality CIGS film. However, there is the problem that most Ga in the CIGS film segregates near the Mo back contact. So the solar cell behaves like a CuInSe2 and lacks the increased open-circuit voltage. In this study we investigated the Ga distribution in CIGS films by using the Ga2Se3 layer. The Ga2Se3 layer was applied on the Cu-In-Ga metal layer to increase Ga content at the surface of CIGS films and to restrict Ga diffusion to the CIGS/Mo interface with Ga and Se bonding. The layer made by thermal evaporation was showed to an amorphous Ga2Se3 layer in the result of AES depth profile, XPS and XRD measurement. As the thickness of Ga2Se3 layer increased, a small-grained CIGS film was developed and phase seperation was showed using SEM and XRD respectively. Ga distributions in CIGS films were investigated by means of AES depth profile. As a result, the [Ga]/[In+Ga] ratio was 0.2 at the surface and 0.5 near the CIGS/Mo interface when the Ga2Se3 thickness was 220 nm, suggesting that the Ga2Se3 layer on the top of metal layer is one of the possible methods for Ga redistribution and open circuit voltage increase.
        4,000원
        111.
        2010.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 국내 31개 호소 지점을 대상으로 동식물플랑크톤 생체량 및 생태학적 모델 적용을 고려한 호소간의 플랑크톤 동태 비교에 목적이 있다. 조사기간 동안 총 89종의 동물플랑크톤(윤충류 70종, 지각류 14종, 요각류 5종)과 554종의 식물플랑크톤(규조류 176종, 녹조류 237종, 남조류 68종 그리고 기타 73종)이 동정 확인 되었다. 플랑크톤 밀도 및 종 다양도는 지점별 및 계절별 상이한 차이를 나타내었다. 전체 호소의 연평균 총 식물플랑크톤
        4,000원
        112.
        2010.05 구독 인증기관 무료, 개인회원 유료
        Recently, the rapid advances in information and communication and network technology and the expansion of digital convergence are changing to ubiquitous network society. Ubiquitous society, expand the temporal and physical space and develops many good thing. but, Hacking, cyber crime, increased privacy, and many problems will occur. In this study, the selection criteria for the appropriate authentication method for developing risk assessment procedures of the service is provided to step 4. (Services, and risk identification step, evaluation of risk-occurrence, evaluation of the extent of damage, Assessment of the level of risk) So, we can easily use the importance and risk to evaluate numerical value of the final risk result.
        4,000원
        116.
        2009.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The content of residual pesticides in commercial agricultural products in Gyeongsangbuk-Do area was investigated for 5 years extending the year 2004 through 2008. The detection rates of residual pesticides in agricultural products by year were similar in range of 11.6~16.4%. But the violation rates showed lower values in the last years from 4.5% of the year 2004 to 0% of the year 2007. The highest residual concentration of each pesticide detected in commercial agricultural products was investigated by year. That is, in the year 2004 and 2005, chlorpyrifos, chlorothalonil, diazinon, endosulfan, ethoprophos, fenarimol and procymidone were detected over the tolerance in kale, parsley, celery, chard and lettuce, and in the year 2006, permethrin in the soybean and peanut. The detection rate and violation rate of pesticides were highly increased in the order of the endosulfan, chlorpyrifos, procymidone, chlorfenapyr, fenitrothion, imazalil, isoprothiolane, methidathion and permethrin. The detection rate and violation rate of pesticides were increased after August every year.
        4,000원
        117.
        2009.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Metal(Zinc) soap and mixed metal(Zn/Ba) soap were synthesized with good structures and characterized by IR and H-NMR. The H-NMR spectrums of the synthesized soaps were in very good accordance with the structures proposed by earlier workers. The mixed metal soaps with various costabilizers(acid or metal content effect), which added in order to investigate the thermal stabilization effect at low and high temperature, were investigated the thermal stabilization effect. The temperature effect is relation to the metal content effect than acid effect. In case of mixed metal soap, the high thermal stabilization effect improved with increasing Barium content. As the Zinc content increase the low temperature thermal stabilization effect improved, but the high temperature thermal stabilization effect showed an opposite tendency.
        4,200원
        118.
        2009.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The types and quantities of Hazmat and Hazmat transportation are gradually increasing, keeping pace with industrialization and urbanization. At present the safety management for Hazmat transportation only considers reducing accident probability, but even when an accident involving Hazmat-carrying vehicles occurs, that is not regarded as a Hazmat-related accident if the Hazmats do not leak out from the containers carrying them. Thus the methods to reduce risk (Risk=Probability×Consequence) have to be developed by incorporating accident probability and consequence. By using Geographic Information System (GIS), a technical method is invented and is automatically able to evaluate the consequence by different types of Hazmat. Thus this study analyzed the degree of risk on the links classified by the Hazmat transport pathways. In order to mitigate the degree of risk, a method of 7-step risk management on Hazmat transportation in railway industries can be suggested. (1st step: building up GIS DB, 2nd step: calculating accident probability on each link, 3rd step: calculating consequence by Hazmat types, 4th step: determination of risk, 5th step: analysis of alternative plans for mitigating the risk, 6th: measure of effectiveness against each alternative, and 7th step: action plans to be weak probability and consequence by the range recommended from ALARP). In conclusion, those 7 steps are used as a standardization method of optimum transportation routing. And to increase the efficiency of optimum transportation routing, optional route can be revise by verification.
        4,200원
        120.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fisher-Tropsch synthesis for the production of hydrocarbon from syngas was investigated on 20% cobalt-based catalysts (20% Co/HSA, 20% Co/Si-MMS), which were prepared by home-made supports with high surface areas such as high surface alumina (HSA) and silica mesopores molecular sieve (Si-MMS). In the gas phase reaction by syngas only, 20% Co/Si-MMS catalyst was shown in higher CO conversion and lower carbon dioxide formation than 20% Co/HSA, whereas the olefin selectivity was higher in 20% Co/HSA than in 20% Co/Si-MMS. In the effect of n-hexane added in syngas, the selectivities of C5+ and olefin were increased by comparing the supercritical phase reaction with the gas phase reaction in addition to reduce unexpected methane and carbon dioxide.
        4,000원