• Title/Summary/Keyword: green development

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Effects of Laser Doping on Selective Emitter Si Solar Cells (레이져를 이용한 도핑 특성과 선택적 도핑 에미터 실리콘 태양전지의 제작)

  • Park, Sungeun;Park, Hyomin;Nam, Junggyu;Yang, JungYup;Lee, Dongho;Min, Byoung Koun;Kim, Kyung Nam;Park, Se Jin;Lee, Hae-Seok;Kim, Donghwan;Kang, Yoonmook;Kim, Dongseop
    • Current Photovoltaic Research
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    • v.4 no.2
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    • pp.54-58
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    • 2016
  • Laser-doped selective emitter process requires dopant source deposition, spin-on-glass, and is able to form selective emitter through SiNx layer by laser irradiation on desired locations. However, after laser doping process, the remaining dopant layer needs to be washed out. Laser-induced melting of pre-deposited impurity doping is a precise selective doping method minimizing addition of process steps. In this study, we introduce a novel scheme for fabricating highly efficient selective emitter solar cell by laser doping. During this process, laser induced damage induces front contact destabilization due to the hindrance of silver nucleation even though laser doping has a potential of commercialization with simple process concept. When the laser induced damage is effectively removed using solution etch back process, the disadvantage of laser doping was effectively removed. The devices fabricated using laser doping scheme power conversion efficiency was significantly improved about 1% abs. after removal the laser damages.

A Character Analysis of the Woodland Edge in point of Landscape Ecology (수림가장자리의 경관생태적 특성분석)

  • Cho, Hyun-Ju;Ra, Jung-Hwa
    • Current Research on Agriculture and Life Sciences
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    • v.25
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    • pp.13-18
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    • 2007
  • The aim of this research is to set improvement guidance a character analysis of woodland edge to cope with the ecological dysfunction of woodland which was caused by massive development project and thoughtless development in country areas. The summary of research result are as follows. 1) From the result of landscape ecology characteristic analysis of woodland in all seven research sites, to begin with, in proportion of appearance by vegetation layer and condition of composition, site 5 showed to be most satisfactory. 2) A width of woodland edge was revealed 7.5m as a minimum, 17.0m as a maximum, and 11.4m as a average and minimum edge was set as 10m according to integrated analysis on each example place. 3) As a result of flexibility analysis, site 1, 2 and 5 was shown high value 3, and it is thought that curve rather than linearity should be maintained in order to increase the ecological function. Also, a phenomenon of straight was prominent, and as a woodland edge, green network and buffering system showed to be somewhat unsatisfactory. 4) Based on the result of character analysis of landscape ecology, main guidelines for improvement of woodland edge were categorized into five in parallel structure and three in vertical structure respectively. The guidelines for improvement of woodland edge suggested by the research has a deep meaning in that it is used as a basic material to induce for controling more systematically or landscape-friendly the defamed forest problems caused by road construction, various development projects, and enlargement of agricultural lands.

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Effect of Color Development of Willemite Crystalline Glaze by Adding NiO (Willemite 결정유에 NiO 첨가가 발색에 미치는 영향)

  • Lee, Chi-Youn;Lee, Byung-Ha
    • Journal of the Korean Ceramic Society
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    • v.47 no.6
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    • pp.598-602
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    • 2010
  • When metal oxides are added into crystalline glaze, colors of glaze and crystals are similar as colorants generally. But the case of NiO in zinc crystalline glaze is different from general color development. When NiO is added to zinc crystalline glaze it can develop two or three colors. The active use of color development mechanism by adding NiO to the zinc crystalline glaze to control color of the base glaze and crystal with stability is investigated. This report is expected to contribute to the ceramic industry in improving application of zinc crystalline glaze. For the experiment of NiO, the quantity of NiO additives is changed to the base glaze for the most adequate formation of willemite crystal from previous research and firing condition: temperature increasing speed $5^{\circ}C/min$, holding 1 h at $1270^{\circ}C$, annealing speed $3^{\circ}C/min$ till $1170^{\circ}C$, holding 2 h at $1170^{\circ}C$ then naturally annealed. The samples are characterized by X-ray diffraction (XRD), UV-vis, and Micro-Raman. The result of the procedure as follows; Ni substitutes for Zn ion then glaze develops blue willemite crystals, as if cobalt is used, on brown glaze base. When NiO quantity is increased to over 5 wt%, willemite size is decreased, and the density of the crystal is increased, at the same time $Ni_2SiO_4$ (olivine) phase, the second phase, has been developed. The excessive NiO is reacted with silicate in the glass then developed green $Ni_2SiO_4$ (olivine), and quantity of $Ni_2SiO_4$ (olivine) is increased as quantity of willemite is decreased. It is proved to create three colors, blue, brown and green by controlling the quantity of NiO to the zinc crystalline glaze and it will improve the multiple use of colors to the ceramic design.

Vision and Developmental Tasks for Korea Agricultural Extension Services for the 21 st Century (21 세기 한국 농촌지도사업의 비전과 발전과제)

  • Lee, Soo-Chul;Lee, Chae-Shik
    • Journal of Agricultural Extension & Community Development
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    • v.7 no.1
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    • pp.101-119
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    • 2000
  • Agricultural Extension Services in Korea have accomplished a significant role in self- sufficiency of rice, a national staple food, through green revolution in 1970's; supplying green vegetables even during the winter season through white revolution in 1980's; and establishing technical agriculture by organizing rural leaders and 4-H members. In 1990s changes were made in international situations under the Uruguay Round multilateral trade negotiations and inauguration of the World Trade Organization. This was followed by localization of the extension staffs and the functions of extension services in Korea changed dramatically from national government to local governments. Thus, a weakened national function resulted in loosening of the linkages of research and extension in central government and local extension offices. Difficulties were reported in diffusion of new agricultural technology and efficient management of extension personnel. Developmental tasks for better extension services for the 21st century in Korea would include recovering national functions of agricultural extension, and developing a new paradigm for extension service. This should include the following measures; 1) Cooperative extension service should be adapted to involve national as well as local governments and non-government organization. 2) The target groups for extension services should be expanded to include farmers, noel residents as well as urban consumers. 3) The role of the extension service should cover agricultural technological diffusion of innovations as well as managerial skills and leadership development for rural organizations. 4) Extension services should be introduced to small farmers as well as consultation services for advanced farms. Diversified approaches should be employed for mama effective services. 5) Pre-service as well as in-service education should be offered to secure better extension educators equipped with knowledge, understanding and abilities on agricultural technology, information, agricultural philosophy, instructional methods and communication skills.

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Variable-color Light-emitting Diodes Using GaN Microdonut Arrays

  • Tchoe, Youngbin;Jo, Janghyun;Kim, Miyoung;Heo, Jaehyuk;Yoo, Geonwook;Sone, Cheolsoo;Yi, Gyu-Chul
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.280-280
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    • 2014
  • We report the fabrication and electroluminescent characteristics of GaN/InxGa1-xN microdonut-shaped light-emitting diode (LED) microarrays as variable-color emitters. The diameter, width, height, and period of the GaN microdonuts were controlled by their growth parameters and the geometrical factors of the growth mask patterns. For the fabrication of microdonut LEDs, p-GaN/p-AlxGa1-xN/u-GaN/u-InxGa1-xN heteroepitaxial layers were coated on the entire surface of n-GaN microdonuts. The microdonut LED arrays showed strong light emission, which could be seen with the unaided eye under normal room illumination. Additionally, magnified optical images of microdonut LED arrays exhibited microdonut-shaped light emissions having spatially resolved blue and green colors. Their electroluminescence spectra had two dominant peaks at 460 and 560 nm. With increasing applied voltage, the intensity of the blue emission peak increased much faster than that of the green emission peak, indicating that the color of the LEDs is tunable. We also demonstrated that EL spectra of the devices could be controlled by changing the size of microdonut LEDs. What we want to emphasize here with the microdonut LEDs is that they have additional inner sidewall facets which did not exist for other typical three-dimensional structures including nanopyramids and nanorods, and that InxGa1-xN single quantum well formed on the inner sidewall facets had unique thickness and chemical composition, which generated additional EL color. The origin of the electroluminescence peaks was investigated by structural characterizations and chemical analyses.

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Protoplast Isolation and Differentiation of Marine Green Alga Monostroma nitidum (해산 녹조류 참홑파래, Monostroma nitidum의 원형질체 분리와 분화)

  • CHO Yong Chul;GONG Yong Gun;YOON Jang-Taek;SUN Sang-Mi;CHUNG Gyu-Hwa
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.32 no.1
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    • pp.117-120
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    • 1999
  • High yields of protoplasts were obtained following enzymatic digestion of the vagetative thalli of marine green alga Monostroma nitidum. The enzyme mixtures containing $4\%$ Cellulase R-10+$3\%$ Macerozyme R-10+$3\%$ Abalone acetone power produced $4.41\times10^6$ protoplasts per 300 mg of fresh tissue. The highest yield of protoplasts was obtained by 270 minutes treatment of the thalli in enzyme solution. Freshly isolated protoplasts were spherical in shape and ranged between $13\~33\mu$m in diameter. The high efficiency of differentiation were obtained by incubating freshly isolated protoplasts in 0.4 M mannitol f/2 medium for 7 days and then transferring to 0.2 M mannitol f/2 medium. Protoplasts began to form new cell walls three days after initial culture and began to germinate after 10 days, and then form a leafy thallus after further culture in f/2 medium. The addition of antibiotics in media inhibited the differentiation of protoplasts in culture.

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A Study on the Urban climate Mitigation Effects with Ecological Landscape Planning with reference to Namyang-Ju Walsanli Master-plan (환경생태계획의 도시기후 변화 대응 가능성 연구 -남양주 월산리 마스터플랜을 중심으로)

  • Moon, Soo Young;Kim, Hyun Soo;Lee, Kwang Bok
    • KIEAE Journal
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    • v.10 no.6
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    • pp.11-19
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    • 2010
  • To meet with the nation's policy of Green Growth, local governments are rushing to propose an ecological urban development plan. And although various studies stress on the need of ecological planning to harmonize development with preservation, we have come to a point in which a quantitative evaluation of how much ecological planning contributes to the environmental load is needed. Through the increasing tendency of making plans based on the development of IT technology, capability of gathering environmental data and scientific instrument, studies on ecological planning's effect towards environmental load has recently begun. This study aims to perform a quantitative evaluation on how ecological planning mitigate urban heat island in the region of Namyang-ju Wallsanli. Three theories were used to mitigate urban heat island ; White network, Green network and Blue network. As a result, the atmosphere temperature was reduced the whole site $1.1^{\circ}C$ and partly $7^{\circ}C$ and the mean radiant temperature was reduced the whole site $1.1^{\circ}C$ and partly $8.7^{\circ}C$ on the modified ecological landscape plan in summer. The PMV index is 0~1 in ecologically modified landscape plan otherwise almost 3 in landscape plan. This study has its limits on the fact that results may differ from the actual plan as the study was performed based on the land use plan and building plan. However, what is important is that it shows a quantitative result of the effect that ecological planning has on surrounding environment and reducing environmental load.

A Development and Application of the Environmental Report for Children (어린이 환경백서 개발 및 적용)

  • Nam, Young-Sook;Jang, Ho-Chang;Park, Tae-Yoon;Moon, Yoon-Sub;Kim, Chan-Kook;Woo, Jung-Ae;Ahn, Mi-Young;Ji, Seung-Hyun;Moon, Kyoung-Hee
    • Hwankyungkyoyuk
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    • v.23 no.4
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    • pp.44-55
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    • 2010
  • The purpose of this study is to develop an environmental report for children and to examine the learning effects of the environmental report on elementary school students. This study is carried out by the survey. The results of this study are as follows. First, the Environmental Report for children, which consists of 8 subjects related to the environmental policy in Korea. 1) Green Growth and Sustainable Policy, 2) Climate Change, 3) Water Supply and Sewage Policy, 4) Sustainable Watershed Management, 5) Conservation of Biodiversity, 6) Resource Recirculation, 7) Environmental Health for Children, and 8) Environmental Dictionary, was systematically developed. Second, the Environmental report developed was examined the effects to third and fourth grade elementary school students in Incheon and Daegu. By dividing elementary school students into two groups: A Control group and an Experimental group, the lessons were respectively executed. In conclusion, the Environmental Report leads to good effects when it is applied to both Environmental Education and the public relation of the Environmental Policy in Korea. Finally, it would be expected to be efficient in learning Sustainable Development and the Environmental Policy.

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Current status on the development of GM plants based on the published articles and patents in Korea (논문 및 특허의 분석을 통한 국내 GM식물의 개발 현황)

  • Lee, Shin-Woo
    • Journal of Plant Biotechnology
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    • v.37 no.4
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    • pp.394-399
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    • 2010
  • During the last three years (2007 to 2009), 1,212 articles of SCI journals, 451 articles of non-SCI journals, and 348 items of registered patents were reported by the research scientists involved in the BioGreen 21 Project, Rural Development Administration and Crop Functional Genomics Center (CFGC), The 21st century Frontier Program, in Korea. Out of these, the percentages of articles or patents directly related to the development of GM plants were 6.0% (SCI), 10.2% (non-SCI) and 12.6% (patents) from BioGreen 21 Project while 15.7% (SCI), 21.1% (non-SCI) and 81.6% (patents) from CFGC, respectively. It was observed that rice and pepper were major host crops for genetic modification mainly to provide the resistance or tolerance activities against to biotic as well as abiotic stresses. Very low cases were reported for the field test of GM plants regarding to the commercialization (less than 15 articles). These observations indicates that more research grants needs to be invested for the risk assessment of GM plants under early developmental stage to commercialize in Korea.

Policy assessment of Agricultural Infrastructure Improvement Project for Preliminary Feasibility Study - Multipurpose Rural Water Development Project in Pangyo District - (농업생산기반정비사업의 예비타당성조사 정책효과 분석 - 판교지구 다목적 농촌용수개발사업을 중심으로 -)

  • Kim, Soo-Jin;Bae, Seung-Jong;Yoo, Seunghwan;Kim, Yoonhyung;Yoon, Sungeun;Kim, Jeonghoon
    • Journal of Korean Society of Rural Planning
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    • v.27 no.1
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    • pp.21-28
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    • 2021
  • Since 2001, the Pangyo district multipurpose rural water development project has been promoted as a new target project for stable supply of agricultural water and improvement of the living environment of rural areas in Seocheon-gun. Detailed data analysis and logic must be reinforced, focusing on the items reorganized by the reorganization of the preliminary feasibility study. The purpose of this study is to promote the smooth promotion of projects by conducting a policy effect assessment following the reorganization of the preliminary feasibility study system. This study conducted a policy assessment of agricultural infrastructure improvement project for preliminary feasibility study. The policy assessment is divided into three parts: project implementation conditions, policy effects and special assessments. The newly established policy effect is to assess the job effects, living conditions impact, environmental evaluation, and safety evaluation that contribute to the quality of life. Sixteen policy assessment items were selected and evaluated quantitatively and qualitatively. The results of the study are expected to provide basic data for the comprehensive judgment of the preliminary feasibility study of agricultural infrastructure improvement project in the future.