• 제목/요약/키워드: Down light

검색결과 469건 처리시간 0.031초

Characteristics of a Rhodobacter sphaeroides mutant selected by increased growth rate under light-limiting photoheterotrophic conditions

  • Lim, Soo-Kyoung;Lee, Il-Han;Lee, Jeong K.
    • 한국식물학회:학술대회논문집
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    • 한국식물학회 1999년도 Proceedings of the 17th Symposium on Plant Biology Environmental Stress and Photosynthesis
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    • pp.55-67
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    • 1999
  • A puc -deleted cell of Rhodobacter sphaeroides grows with a doubling time longer than 160 h under the light-limiting photoheterotrophic ( 3 Watts [W]/㎡) conditions due to an absence of the peripheral light-harvesting B800-850 complex. A spontaneous fast-growing mutant, R.sphaeroides SK101 was ioslate dto have∼40-h doubling at 3 Watts/㎡, while the growth of the mutant was not distinguished from its parental strain during both aerobic and light-saturating photoheterotrphic (10W/㎡) growth. The B875 complex of SK101 under the light-limiting conditions was elevated by 20 to 30% compared with that of the puc -deleted cell, reflecting parallel increase of bacteriochlorophyll and carotenoid contents of the mutant. The formation of B875 complex of SK101 under the anaerobic dark conditions with dimethylsulfoxide was the same as that of the puc-deleted cell. suggesting that the mutation of SK101 result in the altered control of B875 complex formation by light. When puc is restored in SK101 , it is not B875 complex but B800-850 complex which formation is elevated. The mutation of SK101 affected the bchF transcription most drastically to show two to tenfold increase during both aerobic and photoheterotrophic growth. The mutated phenotype of SK101 was complemented with pW2, which contains approximately 100-kb HNA of the photosynthetic gene clusters. The complementing DNA was narrowed down to a 1.1-kb DNA containing orfQ and pufKBA . The mutation of SK101 appeared to be exerted through the mutation of the orfQ gene encoding a putative bacteriochlorophyll -mobilizing protein.

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LED 등기구의 발열량 비교분석 (Comparative Analysis on Heat Radiation of LED Luminaires)

  • 김동건;김일권;유선영;권욱;길경석
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.1530-1535
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    • 2011
  • Heat radiation of LED luminaires has risen a problem when applied indoor. LEDs can save energy with higher efficacy than other light sources. However, their heat radiation may increase power consumption for air-conditioning. Therefore, this paper carried out a comparative analysis on the amount of heat radiation for MR16, E26 bulb, and down-light which will be replaced to LED luminaires. Heat amount of LED-MR16 and LED-downlight was 48% and 87.5% lower than that of conventional lamps, halogen MR16 and E26 CFL, respectively. Consequently, the heat amount and indoor temperature were proportional to the power consumption of luminaire. Therefore, the use of LED luminaire can reduce the amount of heat radiation as well as power consumption.

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광학적 열적 최적화를 통한 6인치 다운라이트 설계 (The Design of 6 inch Down-light by Optimization of the Optical and the Thermal Properties)

  • 김성현;정영기;서범식;양종경;박대희
    • 전기학회논문지
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    • 제60권6호
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    • pp.1178-1182
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    • 2011
  • The best methods for distribution controled of LED lighting fixtures is control to designed LED chip array, lens and reflector. However, lens design need distribution design to reflector for low-wattage LED lighting because of difficulty of production and reduction of light efficiency. In addition, it needs maximize of thermal performance to improve the efficiency and reliability of device. As a result, for the height of reflector 40[mm] and Inclination 25[$^{\circ}$], we can see the best distribution properties, and, in the thermal properties, junction temperature MCPCB 62.9 [$^{\circ}C$], FR4 PCB 89.6 [$^{\circ}C$], FR4 PCB from Via-hole is 63.1 [$^{\circ}C$]. it may improve for thermal properties for makes the Via-hole.

Fabrication of Three-Dimensional Reflective White Pattern using Dry-Film Resist

  • Jun, Hwa Joon;Na, Dae Gil;Kwon, Young Hoon;Kwon, Jin Hyuk
    • Journal of the Optical Society of Korea
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    • 제19권1호
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    • pp.80-83
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    • 2015
  • White reflective patterns are very difficult to fabricate, due to the scattering and reflection of light, especially when the pattern size goes down to micron size. A reflective white barrier structure of height $50{\mu}m$ and width $80{\mu}m$ was fabricated using dry-film resist as an intermediate reverse pattern. The reverse dry-film resist pattern was coated with an $SiO_2$ layer by sputtering, to protect the resist from chemical attack by the radical molecules in UV white resin. The UV white resin was applied on the dry-film resist pattern and then cured with ultraviolet light. The fine three-dimensional reflective patterns were finished by removing the dry-film resist.

장력제어 기법을 이용한 Hybrid형 케이블 구조물의 비선형 시공해석 (Nonlinear Analysis of Hybrid-Typed Cable Structures by Stress Control)

  • 정을석;김승덕
    • 한국공간정보시스템학회:학술대회논문집
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    • 한국공간정보시스템학회 2004년도 춘계 학술발표회 논문집 제1권1호(통권1호)
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    • pp.123-130
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    • 2004
  • The recent large-spatial structures are frequently made from light-weight structural system and it has a good mechanical efficiency and uses new materials. The large space is made by light-weight structural system using tension members mainly, and generally it is called a soft structure. The cable dome structures which are a soft structures are very flexible, the stresses and nodal coordinates of other members are changed when we control the stress of one member. Therefore, we have to do two kind of works for effective and accurate construction of the cable dome structures. The first work is making a working scenario to complete the final objective form and the second is revising constructional errors occurred in process of the actual works. These works are called constructional analysis. At this time, we have to consider geometric nonlinearity to reflect the sensitivity by the initial stresses of cable dome structures, and constructional analysis comes down to a nonlinear problem after all. In this study, we try to approach the constructional analysis of the cable dome structures using the numerical method, and then verify it.

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Genomics and Biotechnology of Plant Adaptation to the Environment

  • Mullet, John E.
    • Journal of Applied Biological Chemistry
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    • 제43권4호
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    • pp.192-196
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    • 2000
  • The molecular basis of plant adaptation to the environment is one of the most complex areas of plant science and an understanding of this subject is critical to our ability to feed an increasing word population. Research on plant adaptation to the environment often involves two complementary approaches; top-down studies of well-adapted plants with the goal of identifying and describing the biochemical basis of adaptation and bottom-up targeted analysis of specific biochemical mechanisms with the goal of understanding how these mechanisms contribute to overall plant performance. This brief review will provide examples of both of these approaches by describing the study of sorghum's adaptation to dry environments and the role of a blue light responsive chloroplast promoter that helps protect plants against damage by high irradiance.

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A Novel Module Control Technology for High-Power LED Backlight

  • Su, Chun-Wei;Chiang, Chin-I;Li, Tzung-Yang;Tsou, Chien-Lung
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.1326-1329
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    • 2009
  • In large-area LCD displays, we have developed two new control technologies for high-power LED backlight. The Novel control technology called scanning control and local gray control. In addition, a conceptual display system power management was developed. We have implemented high power-LED module driving system which can achieve power saving and cost down. Finally, we designed LED light-bar module of the side type as a backlight source. It not only achieved light & thin but also reduced the quantity of LEDs.

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알루미늄 압출재를 적용한 2층 열차 차체의 기초설계 및 구조강도해석 (The Concept Design and Structural Strength Analysis for Double-Deck Train Carbody using Alluminum Extruded Panels)

  • 황원주;김형진;강부병;허현무
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2002년도 춘계학술대회 논문집
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    • pp.364-369
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    • 2002
  • The purpose of this paper is to introduce the concept design and the structural strength of the double-deck rolling stock vehicle. Aluminum is very useful material for the carbody structure due to its characteristic of light weight. Large alumillum extrusion profiles(panels) have toe of merits such as easy production of complicated shapes, reduction of welding and cutting lines, and cutting down the labor cost. AED type is being applied to the standard EMUs and the EMUs Kwangju subway in Korea. Light material recommended the double-deck rolling stock vehicle because the center of gravity of the train is higher and its weight is heavier than those of the normal vehicle. So we applied the technology of the large aluminum extrusion profiles(panels) to the double-deck vehicle. We performed the structural strength analysis and examined its safety.

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접지극 형상에 따른 가로등 주변의 전위분포 (Potential Distribution near Street Linght according to the Grounding Electrode)

  • 이복희;백영환;정동철;안창환;심판섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 제38회 하계학술대회
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    • pp.1453-1454
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    • 2007
  • A street light is an electrical equipment to improve the traffic safety and the security for people in night. However, many accidents due to electric shock have happened in recent, people were interested in the safety of electrical facilities. And people want to know the danger by touch and step voltages. When the electric power lines fall down on the ground, the fault current flows to ground rod and the potential near the ground rod is increased to induce the high touch and step voltages. In this paper, we installed different ground rods with a street light and investigated the electrical potential according to ground methods and the types of ground rod. Finally, we examined the electrical facilities with the experimental result and present the improved technical data for the safety from electric shock

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Neutrinoless Double Beta Decay and Light Sterile Neutrino

  • Jang, C.H.;Kim, B.J.;Ko, Y.J.;Siyeon, K.
    • Journal of the Korean Physical Society
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    • 제73권11호
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    • pp.1625-1630
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    • 2018
  • The recent neutrino experiment results show a preference on normal mass ordering of neutrinos. The global efforts to search for neutrinoless double beta decays undergo a broad gap with the approach to the prediction in three-neutrino framework based on the normal ordering. Current research is to show that it is possible to find a neutrinoless double beta decay signal even with normal ordered neutrino masses. We propose the existence of light sterile neutrino as a solution to the higher effective mass of electron neutrino expected by experiments under operation. A few short-baseline oscillation experiments gave rise to exclusion bound to the mass of sterile neutrino and its mixing with the lightest neutrino. It is demonstrated that results of neutrinoless double beta decays can also narrow down the ranges of the mass and the mixing angle of sterile neutrino.