• 제목/요약/키워드: White-Metal

검색결과 228건 처리시간 0.043초

가변색온도 가로등 구현을 위한 혼색LED의 조명특성 (A Light Characteristics of Mixed-Color LED for the Variable Color Temperature Street Light)

  • 정병호;이강연;최연옥;김대곤;김남오;민완기
    • 전기학회논문지P
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    • 제58권2호
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    • pp.142-147
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    • 2009
  • Conventional HP(high pressure) sodium or Metal-halide lamps have a life span of around one year requiring at least annual replacement and maintenance. High Power LED lights require no regular maintenance further increasing savings on replacement bulbs, access equipment and labour costs. New installations benefit from a substantial reduction in the cost of expensive heavy duty cable required for sodium lighting. Especially, LED light can achieve variable color temperature, high functional performance in the field of street light. There are two main method to achieve variable color temperature function of the street light. one method is using RGB multi-chip LED, the other is using Orange-White LED method. In this paper, it was compare RGB Multi-chip LED with white-orange LED for there characteristics performance.

InGaN계 다중양자우물구조를 병렬 집적화한 백색광소자의 특성 연구 (White Light Emitting Diode with the Parallel Integration of InGaN-based Multi-quantum Well Structures)

  • 김근주;이기형
    • 반도체디스플레이기술학회지
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    • 제3권4호
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    • pp.39-43
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    • 2004
  • The parallel multi-quantum well structures of blue and amber lights were designed and grown in metal-organic chemical vapor deposition by utilizing integration process on epitaxial layers. Samples were deposited for 5 periods-InGaN multi-quantum well layers for blue light emission and partially etched in order to regrow the 3 periods-InGaN multi-quantum wells for amber light. The blue and amber photoluminescence spectra were observed at the peak wavelengths of 475 and 580 nm, respectively. The chromatic coordinates of the white emitting diode were 0.31 and 0.34.

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Volatile Discrimination of Irradiated and Fumigated White Ginseng Powders at Different Storage Times and Temperatures Using the Electronic Nose

  • Shin, Jung-Ah;Kwon, Joong-Ho;Lee, Ki-Teak
    • Preventive Nutrition and Food Science
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    • 제11권3호
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    • pp.237-242
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    • 2006
  • The pattern of volatile emissions from white ginseng powders (WGP) that were treated with selected preservatives was investigated during 5-months of storage (at -10 and $25^{\circ}C$) by an electronic nose system equipped with 12 metal-oxide sensors. WGP were treated with gamma radiation at 5 kGy, commercial methyl bromide (MeBr), and phosphine fumigations. Electronic nose differentiated the volatile patterns of the WGP with each different preservative treatment. In addition, each volatile pattern was affected by both storage time (1, 2 and 5 months) and temperature (-10 and $25^{\circ}C$). After 5-months of storage, the least change of volatile patterns was observed from WGP fumigated with phosphine at $-10^{\circ}C$. The result also showed that volatile changes in WGP were much more affected by storage time than by storage temperature.

문경 단붕탄광 폐석장 유출수의 조성변화 (Changes in Compositions of Effluent Water from Mine Wastes in Danbung Mine, Munkyung)

  • 지상우;김선준;안지현
    • 대한지하수환경학회지
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    • 제4권4호
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    • pp.169-174
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    • 1997
  • 경상북도 문경 부근에 위치하는 폐광산인 단붕탄광의 폐석장에서 유출되는 산성광산수의 조성변화를 보기 위하여 1995년 장마 전, 후 및 1997년 장마 전에 하천수와 퇴적물을 채취하여 금속원소의 함량을 분석하였다. 건기 동안에 폐석장 내에서 누적된 황철석의 산화산물이 강우량의 증가에 의해 유출됨으로써 장마 전보다 장마후에 하천수의 pH가 낮아지고 금속농도가 증가하였다. 2년의 시간이 경과한 후는 pH가 1이상 낮아졌으며 금속농도는 2배 이상 증가하여 산성광산수에 의한 오염의 진행이 심화되고 있음을 나타냈다. 적색과 백색으로 나타나는 Fe와 Al수산화물 및 황산염 등의 침전물의 공간적인 분포도 산성광산수의 조성변화를 반영하여 변화하였다. 1995년에 비해 1997년에는 적색침전물이 더 멀리까지 분포하고 백색침전물은 1995년도에는 발견되지 않던 하류까지 확장 분포하였으며 이들 침전물에 결합된 금속이온들의 함량도 수배 내지 수십 배 증가하였다.

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전도성 액체기반 정상표면탄성파(CL-SSAW)를 이용한 백혈구로부터의 말라리아 기생충 분리 (Malaria Parasite Separation from White Blood Cells Using Conductive Liquid-Based Standing Surface Acoustic Wave (CL-SSAW))

  • 지현슬;남정훈;임채승
    • 대한의용생체공학회:의공학회지
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    • 제40권5호
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    • pp.151-157
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    • 2019
  • An acoustofluidic device using conductive liquid-based electrodes was developed for malaria parasite separation from white blood cells. In this device, the electrode channels filled with a conductive liquid were used to generate standing surface acoustic waves (SSAWs) in a fluidic channel, which can overcome the limitation of conventional patterned metal electrodes. Separation performance of the device was evaluated using fluorescent polystyrene particles with two different sizes (2 and $10{\mu}m$ diameters), which were successfully separated. In addition, a mixture of malaria parasites and white blood cells were also efficiently separated with high purity of ~98% in the CL-SSAW device at the flow rate of $12{\mu}l/min$.

란탄계 금속 착화합물을 이용한 유기 전기 발광 소자의 에너지 밴드 구조의 연구 (Energy Band Schemes of Organic Electroluminescence Devices Using Lanthanide Metal Complexes)

  • 표상우;이재혁;이한성;이승희;김영관;김정수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 D
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    • pp.1735-1737
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    • 1999
  • In this study, several lanthanide complexes such as Eu$(TTA)_3$(Phen). Tb$(ACAC)_3$(Cl-Phen) were synthesized and the white-light electroluminescence (EL) characteristics of their thin films were investigated. where the devices having structures of anode/TPD/Tb$(ACAC)_3$(Cl-Phen)/Eu$(TTA)_3$(Phen)/$Alq_3$ or $Bebq_2$/ cathode and the low work function metal alloy such as Li:Al was used as the electron injecting electrode (cathode). Details on the white-light-emitting characteristics of these device structures were explained by the energy band diagrams of various materials used in these structures, where the energy levels of new materials such as ionization potential (IP) and electron affinity (EA) were measured by cyclic voltametric method.

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Scientific Analysis of Pigments in 20th Century Paintings for Selected Historical Churches of the Bohol, Philippines

  • Roxas, Gracile Celine;Han, Min Su;Moon, Dong Hyeok
    • 보존과학회지
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    • 제33권6호
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    • pp.507-518
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    • 2017
  • Through a combination of scientific analytical methods, the coloring materials used in $20^{th}$ century paintings in historical churches of Baclayon, Dauis and Loay, which are municipalities in Bohol, Philippines, were studied. Inorganic pigments were identified using SEM-EDS and XRD. Iron-based pigments were commonly found in the paintings, yielding dark yellow and brown colors. Zinc oxide was identified as the white pigment in the ceiling paintings of Dauis Church and Loay Church, while titanium dioxide was detected in the column painting in Baclayon Church. Organic analysis showed the presence of Pigment Yellow 3, a synthetic organic pigment. Paint layers, as well as other components of the samples such as grounds and metal leaves, were examined microscopically. It was observed that different types of grounds were applied on different types of surfaces. Moreover, organic pigments were found in combination with white extender materials. Microscopic examination also revealed alterations in the artworks, such as the overpaint layer found in the samples from Baclayon Church cornice and the imitation metal leaf layers applied over the original gilt surface in the Loay Church retablo.

The Material Analysis and Conservation of Porcelain Enamel - Focus of Porcelain Enamel Excavated at Former President Yoon Bosun's Birthplace -

  • Lee, Jung-Min
    • 보존과학회지
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    • 제35권1호
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    • pp.33-40
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    • 2019
  • During the conservation and maintenance of the birthplace center yard of President Asan Yoon Bosun, four porcelain enamel dishware were excavated from the central yard well. The glaze layer of excavated enamel was severely damaged; hence, the conservation process was done rapidly. In addition, scientific investigation and analysis were conducted to confirm the material properties of the glaze layer. It was confirmed that the outer surface was inverted and dried, while the inner surface was upright and fired during the glazing and drying process by measuring the film thickness. By examining the breakup phenomenon, the breaking up of the white enamel on the colored enamel was confirmed. This indicates that the colored glaze rose to the surface depending on the density of the colored glaze and white glaze. The investigation of the cross-section of the film confirmed that the lower layer formed according to the bonding properties with metal during the glazing process. Analysis of the constituents of the identified lower layer confirmed that there are differences between the specific components of the metal oxide of the lower layer and the surface color development of the upper layer.