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        검색결과 323

        141.
        2013.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본고에서는 2011년 국토지리정보원 발간 세계전도 및 대한민국 주변도의 표준매트릭스를 기초로 다국어 매트릭스의 스페인어 매트릭스를 작성한 과정을 다루었다. 매트릭스의 작업 과정은 기존 스페인어 지명 표기의 수집 과정과 공인된 스페인어식 표기법이 없는 한국, 중국, 일본 등의 지명을 스페인어로 표기하는 과정으로 구성되었다. 스페인의 식민지 지배의 역사적 경험으로 인해 스페인어는 16세기 초 이후 외국 지명의 스페인어식 표기가 지속적으로 이루어졌다. 스페인어 사용자들에게 익숙한 발음으로 전환하고 언중들이 지명의 의미를 알기 쉽게 스페인어로 의미를 표기하는 것이 특징이었으며, 외국 지명의 상당 부분이 ‘스페인어화’된 경향이 있었다. 이에 비해 우리나라의 외국 지명 표기는 의미의 전달보다는 한국어의 발음을 중요시하는 경향이 있었다. 스페인어 매트릭스 작성 과정에서는 스페인어 지도집을 기준으로 삼았고, UNGEGN의 자료 및 각국의 지도관련 사이트 등을 이용하여 공인된 지명을 최대한 반영하였다. 스페인어 표기가 없는 상세한 지명은 국립국어원의 로마자어 표기법 및 스페인어 표기세칙을 따라 스페인어로 변환하였다.
        4,800원
        143.
        2013.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        (Y123) powders for the fabrication of bulk superconductors were synthesized by the powder reaction method using (99.9% purity), (99.75%) and CuO (99.9%) powders. The raw powders were weighed to the cation ratio of Y:Ba:Cu=1:2:3, mixed and calcined at in air with intermediate repeated crushing steps. It was found that the formation of Y123 powder was more sensitive to reaction temperature than reaction time. The calcined Y123 powder and a mixture of (Y123 + 0.25 mole + 1 wt.% , (Y1.5)) were used as raw powders for the fabrication of poly-grain or single grain superconductors. The superconducting transition temperature () of the sintered Y123 sample was 91 K and the transition width was as large as 11 K, whereas the of the melt-grown Y1.5 sample was 90.5 K and the transition width was 3.5 K. The critical current density () at 77 K and 0 T of the sintered Y123 was 700 , whereas the of the top-seeded melt growth (TSMG) processed Y1.5 sample was . The magnetic flux density (H) at 77 K of the TSMG-processed Y123 and Y1.5 sample showed the 0.53 kG and 2.45 kG, respectively, which are 15% and 71% of the applied magnetic field of 3.5 kG. The high H value of the TSMG-processed Y1.5 sample is attributed to the formation of the larger superconducting grain with fine Y211 dispersion.
        4,000원
        144.
        2013.04 구독 인증기관 무료, 개인회원 유료
        Slips and falls are associated with many occupational injuries in Korea. It is also estimated that slipping are major contributors to slip, trip and fall injury burden. So「LOCAL RULE ON OCCUPATIONAL SAFETY AND HEALTH STANDAR D」must be improved, especially article 3(prevention of slip, trip and fall). The primary purpose of the present study is to determine if , and to what extent, the standard could be improved in present environment. In order to fulfill our objective, the another regulation in Korea and foreign countries were investigated and reviewed. Many kind of standard, mandatory documents and guideline were also reviewed. And then, regulations, standard, guideline etc. reviewed were compared with each others. The article 3 was revised as below. 1. The floors of the traffic route in workplace shall have no hole or slope, or be uneven or slippery so as, in each case, to expose employees to slip, trip and fall risk, except if adequate measures have been taken to prevent a employees falling. 2. The employer shall design, install and fix the drain for effective drainage if fluid contaminants were frequently occurred. So far as is reasonably practicable, An employer shall keep the workplace clean, sanitary, and dry so that employees won't have any risk to tripping or slipping at the workplace. 3. To facilitate cleaning, every floor, workplace, and passageway shall be, so far as is reasonably practicable, kept free from protruding objects, splinters, holes, etc. Also, some criteria was developed in this study. Standard and criteria developed in this study will help to prevent slip, trip, and fall injuries.
        4,200원
        146.
        2013.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        현재 고준위 방사성 폐기물 심층 처분 시스템에서 기본 완충재 물질로서 건조밀도 1.6 g/cm3의 경주산 칼슘 벤토나이트 를 사용하고 있으나, 열전도도가 낮은 단점이 있다. 따라서 본 연구에서는 기준 완충재의 열전도율을 0.8 W/mK에서 1.0 W/mK로 향상시키기 위한 목적으로 다양한 첨가제를 다양한 혼합 방법을 통해 배합하고 열전도도를 측정하였다. 첨가제는 CNT(Cabon Nano Tube), Graphite, Alumina, CuO 및 Fe2O3 등을 사용하였다. 혼합 방법의 경우, 핸드 믹서기를 통한 건식 혼합, 습식 Milling 혼합, 건식 Ball Mill 혼합 등을 실시하였다. Ball Mill 혼합의 경우가 가장 균일하게 혼합되었기 때문에, 값 의 편차가 가장 적었고 열전도도 증가율이 가장 좋았다. 지금까지 수행된 시험에서 소량의 고열전도 물질의 첨가로 경주산 칼슘 벤토나이트의 열전도도를 1.0 W/mK 수준으로 용 이하게 증가시킬 수 있음을 실험적으로 확인할 수 있었다. 결론적으로, 본 연구에서 제시된 열전도 향상 방법은, 첨가제 혼합 이 벤토나이트의 기본 성질인 팽윤압과 수리전도도에 미치는 영향까지 제시된다면, 국내 고준위폐기물 처분장의 개념 설계에 유용하게 활용될 수 있을 것으로 기대된다.
        4,200원
        147.
        2013.03 구독 인증기관 무료, 개인회원 유료
        전도성 고분자 PFO(Polyfluorene)에 양전극 ITO와 음전극으로 AI 를 추가한 단순한 양극성 구조의 ITO/PFO/Al 소자를 제작하였다. PFO에 BaTIO₃나노세라믹스 분말을 중량비로 0wt%, 10wt%, 20wt% 와 30wt% 로 달리한 4종류의 시편에 만들고, Keithley 사의 2400 Sourcemeter를 이용하여 0V에서 21V까지 DC전압을 인가하면서 소자에 흐르는 전류량을 관찰하였다. 수 나노 크기의 BaTIO₃분말의 첨가는 PFO/AI 계면에서의 전위장벽을 감소시켜 Fowler-Nordheim Tunneling이 시작되는 전압이 BaTIO₃가 첨가되지 않은 시편의 경우에 비하여 7V에서 최대 10V가 낮아진 결과를 얻었다. 소자에 흐르는 최대 전류값은 인가 전압 DC21V일 때 BaTIO₃첨가량에 비례하여 4배에서 5.5배까지 증가하였다. BaTIO₃의 첨가효과는 20wt% 이상 첨가된 경우 효과가 포화되기 시작하여, 30wt%의 BaTIO₃를 첨가한 시편의 전류량은 오히려 감소하였고 전류주입도 어려워지는 상반된 결과를 얻었다. 이것은 첨가한 나노 분말의 표면전하가 만드는 미세전계의 영향이 인접한 거리에서 서로 중첩되어 전류의 흐름이 오히려 감소하는 결과를 보인 것을 판단된다. 이로서 강유전체가 첨가된 전도성 고분자/금속 계면의 I-V 특성은 나노 세라믹스 분말의 표면전하가 만드는 국소미세전계의 영향을 받아 Trap Charge Limited Current 모델에 부합하는 결과를 가짐을 알 수 있었다.
        4,000원
        148.
        2013.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, a three dimensional numerical analysis tool was applied to study the PEMFC performance characteristics. The porosity and electrical conductivity of GDL and CL as well as the relative humidity of anode and cathode channel gas were selected as simulation parameters. The porosity of GDL and CL was varied as 0.3, 0.5, and 0.7. The relative humidity of anode and cathode was varied as 0, 20, 40, 60, 80, and 100 percent. The electrical conductivity of GDL and CL was varied as 1, 5, 10, 50, 102, and 104 1/Ω·m. For a constant cell voltage condition, the maximum current density was obtained at GDL porosity of 0.7, anode relative humidity of 100 percent, cathode relative humidity of 60 percent, and electrical conductivity of 104 1/Ω·m for GDL and CL. As the porosity of GDL and CL increases, current density increases because reactant gases diffuse well. As the electrical conductivity of GDL and CL increases, current density increases due to increased electron transfer rate. As anode relative humidity increases, current density increases. Unlike anode, current density increases when cathode relative humidity increases from 0 percent to 60 percent. Then current density decreases when cathode relative humidity increases from 60 percent to 100 percent.
        4,000원
        149.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        With increase in operating temperature of gas turbine for higher efficiency, it is necessary to find new materials of TBC for replacement of YSZ. Among candidate materials for future TBCs, zirconate-based oxides with pyrochlore and fluorite are prevailing ones. In this study, phase structure and thermal conductivities of oxide system are investigated. system are comprised by selecting as A-site ions and as B-site ion in pyrochlore structures. With powder mixture from each oxide, oxides are fabricated via solid-state reaction at . Either pyrochlore or fluorite or mixture of both appears after heat treatment. For the developed phases along compositions, thermal conductivities are examined, with which the potential of compositions for TBC application is also discussed.
        4,000원
        150.
        2012.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Large single grain Gd1.5Ba2Cu3O7-y (Gd1.5) bulk superconductors were fabricated by a top-seeded melt growth (TSMG) process using an NdBa2Cu3O7-y seed. The seeded Gd1.5 powder compacts with a diameter of 50 mm were subjected to the heating cycles of a TSMG process. After the TSMG process, the diameter of the single grain Gd1.5 compact was reduced to 43 mm owing to the volume contraction during the heat treatment. The superconducting transition temperature (Tc) of the top surface of the single grain Gd1.5 sample was as high as 93.5 K. The critical current densities (Jcs) at 77 K and 1T and 1.5 T were in ranges of 25,200-43,900 A/cm2 and 10,000-23,000 A/cm2, respectively. The maximum attractive force at 77 K of the sample field-cooled using an Nd-B-Fe permanent magnet (surface magnetic field of 0. 527 T) was 108.3 N; the maximum repulsive force of the zero field-cooled sample was 262 N. The magnetic flux density of the sample field-cooled at 77 K was 0.311T, which is approximately 85% of the applied magnetic field of 0.375 T. Microstructure investigation showed that many Gd2BaCuO5 (Gd211) particles of a few μm in size, which are flux pinning sites of Gd123, were trapped within the GdBa2Cu3O7-y (Gd123) grain; unreacted Ba3Cu5O8 liquid and Gd211 particles were present near the edge regions of the single grain Gd1.5 bulk compact.
        4,000원
        151.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper reports the microstructures and thermal conductivities of -SiC composite ceramics with size and amount of SiC. We fabricated sintered bodies of -x vol.% SiC (x=10, 20, 30) with submicron and nanosized SiC densified by spark plasma sintering. Microstructure retained the initial powder size of especially SiC, except the agglomeration of nanosized SiC. For sintered bodies, thermal conductivities were examined. The observed thermal conductivity values are 40~60 W/mK, which is slightly lower than the reported values. The relation between microstructural parameter and thermal conductivity was also discussed.
        4,000원
        154.
        2012.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Li1+xAlxTi2-x(PO4)3(LATP) is a promising solid electrolyte for all-solid-state Li ion batteries. In this study, LATP isprepared through a sol-gel method using relatively the inexpensive reagents TiCl4. The thermal behavior, structuralcharacteristics, fractured surface morphology, ion conductivity, and activation energy of the LATP sintered bodies areinvestigated by TG-DTA, X-ray diffraction, FE-SEM, and by an impedance method. A gelation powder was calcined at 500oC.A single crystalline phase of the LiTi2(PO4)3(LTP) system was obtained at a calcination temperature above 650oC. The obtainedpowder was pelletized and sintered at 900oC and 1000oC. The LTP sintered at 900~1000oC for 6 h had a relatively low apparentdensity of 75~80%. The LATP(x=0.3) pellet sintered at 900oC for 6 h was denser than those sintered under other conditionsand showed the highest ion conductivity of 4.50×10−5S/cm at room temperature. However, the ion conductivity of LATP(x=0.3) sintered at 1000oC decreased to 1.81×10−5S/cm, leading to Li volatilization and abnormal grain growth. For LATPsintered at 900oC for 6 h, x=0.3 shows the lowest activation energy of 0.42eV in the temperature range of room temperatureto 300oC.
        4,000원
        155.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the effects of the secondary tasks such as sending text message (STM) and searching navigation (SN) on skin conductance level (SCL) and driving performance of relatively aged and high-experienced drivers. The s
        4,000원
        158.
        2012.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        John Wesley(1703-1791), an excellent evangelist and leader of renewal movement of the 18th century in both sides of the Atlantic, regarded evangelism as his life-long mission. To use Wesley’s terminology, evangelism is the dispensation of the gospel. Chapter 2 treats Howard A. Snyder’s missional flavor of John Wesley. According to Snyder, the following five significant biblical themes are full of missional flavor: image of God(imago Dei), prevenient(or preceding) grace, salvation as healing, the “perfecting” of Christian character, and the restoration of all things. Chapter 3 handles Wesley’s evangelism revealed in his sermons. Evangelism is not just a special task of designated gifted ones, but a general task of all believers. An evangelist should be a (wo)man of love. Wesley suggests a four-step evangelism method based on the means of grace. The first two steps are providing the opportunities of listening/conversation and reading the Bible and good books. The last two steps are having exaltation in small groups and praying together. The social religion, Wesley’s renowned terminology, contains a good lesson for Christians. This can be applied not only for evangelistic purposes, but for building Christian virtue as well. As stated by Wesley, the focus of the parable of salt and light is evangelism in the world. The author concludes this article by emphasizing an occasion which reveals Wesley’s ceaseless zeal for evangelism. Despite heavy rainfall early in the morning and difficulties in borrowing a horse, Wesley was determined to carry out his scheduled rural area evangelism. Nothing stopped Wesley’s passion to spread the glad tidings of salvation.
        6,400원
        159.
        2012.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        양극산화 알루미나(AAO)막의 나노 사이즈 미세공(세공 크기 20 nm, 10 nm 및 200 nm)을 주형으로 사용하여 전도성 고분자인 폴리피롤, 폴리아닐린 중합체 및 폴리피롤/폴리아닐린 공중합체 나노와이어를 제조하였다. 미세공 주형 내에서 전도성 고분자의 성장은 세공의 벽면을 따라 튜브 형태로서 성장하였으며, 3시간 이후에는 내부가 완전히 채워진 나노와이어가 형성되었다. AAO 막을 수산화나트륨 용액으로 퍼리하여 세공 내에 형성된 전도성 고분자 나노와이어를 회수 하였으며. 회수된 나노와이어 직경과 길이는 주형 막의 세공 형상과 일치하였다. 통상의 용액 중합법으로 제조된 전도성 고분자 분말과 비교하여 주형 합성법으로 제조된 전도성 고분자 나노와이어는 결정성과 열적 안정성이 향상되었으며, 전기 저항은 4~60% 감소하였다.
        4,200원
        160.
        2011.12 구독 인증기관 무료, 개인회원 유료
        그라비어 오프셋 인쇄 공법을 이용하여 미세 패턴 전극을 형성하였고, 패턴 형성에 대한 블랭킷의 영향을 알아보기 위해 블랭킷의 용제 흡수량과 경도의 차등을 주어 실험을 하였다. 그라비어 오프셋은 블랭킷이 얼마나 용제의 흡수와 배출을 적절한게 하느냐에 따라서 연속 인쇄성과 여러 가지 인쇄적성에 큰 영향을 끼치게 된다. 총 4가지의 종류별 블랭킷의 테스트 결과 흡수량이 가장 높고 경도가 가장 낮은 블랭킷이 4가지 블랭킷 중 가장 인쇄적성과 전도성이 우수함을 알 수 있었다.
        4,000원