• Title/Summary/Keyword: Green emission

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Synthesis and Optical Characteristics of Green-Emitting (Mg,Zn)$Al_2O_4:Mn^{2+}$ Phosphor for 3D- PDP Applications

  • Han, Bo-Yong;Yoo, Jae-Soo;Heo, Eun-Gi;Yoo, Young-Gil
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.272-275
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    • 2009
  • A new green phosphor, ($Mg_{1-x-yZnx)$)$Al_2O_4:Mn^{2+}{_y}$ (0 x 0.6, 0.001 y 0.01), was synthesized by a flux-assisted solid reaction and its vacuum ultraviolet (VUV) excitation and emission characteristics were examined in this study. The chromaticity and peak intensity of the $(Mg_{0.79}Zn_{0.2})Al_2O_4:Mn^{2+}{_{0.01}}$ (x = 0.177, y = 0.745) phosphor were found to be more desirable than that of $Zn_2SiO_4:Mn^{2+}$ (x = 0.216, y = 0.72) phosphor as a green primary color.

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Preparation and Luminescent Properties of Zn2SiO4:Mn,Al Green Phosphors (Zn2SiO4:Mn,Al 녹색 형광체의 제조와 발광특성)

  • Lee, Ji-Young;Yu, Il
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.4
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    • pp.363-366
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    • 2007
  • [ $Zn_2SiO_4:Mn$ ] green phosphors doped with $NH_4Cl$ and Al for PDP were synthesized by solid state reaction method. The luminescence of 532 nm in $Zn_2SiO_4:Mn$ phosphors was associated with $^4T_1{\to}^6A_1$ transition. Photoluminescence intensity of $Zn_2SiO_4:Mn$ doped with $NH_4Cl$ 15 mol% increased about two times as compared with that of $NH_4Cl$ non-doped sample. The color of the emission of Al-doped $Zn_2SiO_4:Mn$ phosphors changed to yellowish green.

Preparation and Luminescent Properties of Zn2SiO4:Mn, Ga Phosphors (Zn2SiO\4:Mn, Ga 형광체의 제조와 발광특성)

  • Lee, Ji-Young;Yu, Yun-Sik;Yu, Il
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.2
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    • pp.158-162
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    • 2009
  • $Zn_2SiO_4$:Mn green phosphors doped with Ga for PDP were synthesized by solid state reaction method. Photoluminescence measurements showed a new emission peak at around 600 nm for $Zn_2SiO_4$:Mn phosphors doped with Ga. Also, the luminescent color with doping $Ga^{3+}$ in the $Zn_2SiO_4$:Mn phosphors changed to green from yellowish green. Consequently, the new peak and charge of the luminescent color in the $Zn_2SiO_4$:Mn, Ga phosphors were attributed to $^2E{\rightarrow}^6A_2$ transition of $Mn^{4+}$.

Information and Communications Technology, Economic Growth, and Carbon Emission Levels: The Case of South Korea

  • Lee, Jung-wan;Unger, Barry
    • Journal of Distribution Science
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    • v.10 no.6
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    • pp.7-15
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    • 2012
  • The paper deals with the impact of information and communications technology on carbon emissions and economic growth in South Korea. The quarterly time series data from the first quarter of 1970 to the third quarter of 2010 (163 observations) are collected and retrieved from the Bank of Korea database. The paper examines long-run equilibrium relationships using cointegration techniques and Granger causality with vector error correction models. In directional causality tests, information and communications technology shows highly significant positive effects on economic growth and marginal effect on carbon emissions. Carbon emissions and economic growth exhibit an inverse relationship with each other; that is, carbon emissions have an inverse relation to economic growth and economic growth does not significantly affect carbon emissions in South Korea. We also note possible implications regarding growth policies and the information communications technology and "green" technology sectors for economies in the range represented by Korea's 1970 - 2010 data.

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$Nd^{3+}$ ACTIVARED OXIDE NONLINEAR LASER CRYSTALS IN THE GREEN

  • Garcia Sole, J.;Jaque, D.;Molero, F.;Capmany, J.
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1998.06a
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    • pp.19-22
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    • 1998
  • In this work, nonlinear crystals are investigated as investigated ad future diode pumped host laser materials in the green. Optical properties( absorption, emission, secind harmonic generation, and continuous wave lader oscillation in the green) of the most relevant neodymium activeated oxide lader crystals{{{{ ({LiNbO }_{ 3}:MgO, YAI({BO }_{3})_{4} and {LaBGeO }_{ 5})}}}} are investigated and compared under similar experimental conditions

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Effect of Si-doping on the luminescence properties of InGaN/GaN green LED with graded short-period superlattice

  • Cho, Il-Wook;Lee, Dong Hyun;Ryu, Mee-Yi;Kim, Jin Soo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.280.1-280.1
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    • 2016
  • Generally InGaN/GaN green light emitting diode (LED) exhibits the low quantum efficiency (QE) due to the large lattice mismatch between InGaN and GaN. The QE of InGaN-based multiple quantum wells (MQWs) is drastically decreased when an emission wavelength shifts from blue to green wavelength, so called "green gap". The "green gap" has been explained by quantum confined Stark effect (QCSE) caused by a large lattice mismatch. In order to improve the QE of green LED, undoped graded short-period InGaN/GaN superlattice (GSL) and Si-doped GSL (SiGSL) structures below the 5-period InGaN/GaN MQWs were grown on the patterned sapphire substrates. The luminescence properties of InGaN/GaN green LEDs have been investigated by using photoluminescence (PL) and time-resolved PL (TRPL) measurements. The PL intensity of SiGSL sample measured at 10 K shows stronger about 1.3 times compared to that of undoped GSL sample, and the PL peak wavelength at 10 K appears at 532 and 525 nm for SiGSL and undoped GSL, respectively. Furthermore, the PL decay of SiGSL measured at 10 K becomes faster than that of undoped GSL. The faster decay for SiGSL is attributed to the increased wavefunction overlap between electron and hole due to the screening of piezoelectric field by doped carriers. These PL and TRPL results indicate that the QE of InGaN/GaN green LED with GSL structure can be improved by Si-doping.

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A Sustainable BSC-IT based Framework for Assessing the Strategic Impacts of Green IT Initiatives (그린IT 이니셔티브들 전략적 영향들을 평가하기위한 지속가능한 BSC-IT 기반 프레임워크)

  • Ruiz, Luis;Park, Jeong-Sun
    • Journal of the Korea Safety Management & Science
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    • v.14 no.4
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    • pp.205-210
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    • 2012
  • We don't have time to waste, time is running, and the global warming is an issue that concerns to all of us. Information technology, which on a global level is responsible for 2% of emission of greenhouse gases. However, the remaining 98% is seen as an opportunity for IT to help our planet, our companies and our society. The purpose of this paper is to analyze green information technology (IT) initiatives and their strategic impact. And to have done this, we develope and create a very useful balanced-scorecard framework to explain, understand, and identify the direct and indirect contribution of green IT initiatives. The green IT evaluation framework, called here a sustainable green IT balanced scorecard, integrates the four BSC-IT perspectives with the Zuboff's automate/informate goals of information systems and the contribution of the sustainability (economic, social and environment). This study also seeks to answer the following questions: 1) what are the driving forces for implementing green IT initiatives? 2) How can an analytical framework be built to systematically analyze the benefits and strategic contribution of green IT initiatives? And 3) how green IT initiatives impact the strategic goals of a firm and how they can contribute to the triple bottom line? The framework demonstrates to be useful as a management tool to hopefully integrate environmental and social management with the general management of a company. Besides, the strategy map and measures for each cell of the framework are provided.

Emission Characteristics of Vehicles in CVS-75 Mode Under Various Conditions of Driving Distance, Driving Pattern, and Engine Pre-Heating (CVS-75모드에서 차량의 주행거리, 주행패턴 및 엔진 예열상태에 따른 배출가스 특성)

  • Eom, Myung-Do;Baik, Doo-Sung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.5
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    • pp.503-508
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    • 2012
  • Recently green house gas emission problem has been issued because $CO_2$ emission is known to cause global warming. Hence, introduces more stringent emission and fuel economy requirements in various countries, including Korea. In this research, $CO_2$ emission factor characteristics of in-use cars, which are the most dominant vehicle type in Korea, were studied, and 129 gasoline vehicles, 100 diesel vehicles, and 34 LPG vehicles were tested on a chassis dynamometer. In the tests, CO and $CO_2$ emissions as well as fuel reduction rates weremeasured. The tests were conducted in the CVS-75 mode, which has been considered for developing emission factors for regulating emissions from light-duty vehicles in Korea. Through experiments, correlations among displacement, fuel consumption efficiency, fuel type, mileage, driving pattern, and $CO_2$ emission were investigated.

A Research on the Status of Greenhouse Gas Emission Factors from Livestock Sector to Create a National Greenhouse Gas Inventories (국가 온실가스 인벤토리 축산부문 작성을 위한 온실가스 배출계수 개발 현황에 관한 연구)

  • Lee, Jin Eui;Lee, Hyun Ju;Park, Kyu Hyun;Choi, Byong Yang;Ra, Chang Six
    • Journal of Animal Environmental Science
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    • v.17 no.sup
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    • pp.21-34
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    • 2011
  • In this study, researches on the development of country specific greenhouse gas measurement and sampling methods from the livestock sector were reviewed. Research on greenhouse gas emission factors was started in early 2000 but was not actively involved in the development of livestock sector based emission factor: since 2009, works are underway for the development of livestock sector based emission factor. Most of the research on greenhouse gas emission in the field of animal studies were done by National Institute of Animal Science, because of the uniqueness of the research laboratories. Methods of emission measurement are still not internationally certified and therefore, measurement and sampling methods for Korea livestock sector are being studied, consulting the worldwide research trends. Flux chamber method are commonly using in Korea for green house gas emission factors measurement. In recent years, continuous measurement of the microclimate was introduced to measure greenhouse gases from livestock manure storage facilities and the micrometeorology method should be adapted as recommended by Intergovernmental Penal on Climate Change (IPCC) Guideline.

The Domestic Response Strategies for the Mutual Recognition Arrangement System to Greenhouse Gas (온실가스 국제상호인정 체계에 관한 국내대응방안)

  • Lee, Hae-Jung;Chung, Young-Bae
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.40 no.3
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    • pp.83-91
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    • 2017
  • Climate change has been identified as one with the greatest challenges facing nations, government, business and over future decades. Activities to reduce greenhouse gas emissions by the Kyoto Protocol, the international community has been in progress. Korea also has introduced the Emission trading system to reduce greenhouse emission from the supervision of the government. Greenhouse gases emissions quantity should be internationally recognized. Mutual Recognition Arrangement should be recognized as the same greenhouse gas emission. International recognition of domestic verification body of international mutual recognition is required. Efforts are needed to secure the equivalence between the emission rights through direct cooperation with the relative nation accreditation body. Early entry into the IAF/PAC GHG MLA is essential for demonstrating equivalence between greenhouse gas emissions. Emissions trading will also require connection to the EU ETS, California, USA, and Tokyo, Japan to link Emissions trading. In the case of establishing accreditation standards and accreditation criteria, it will be necessary to distinguish between the domestic Energy Target Management System and the Emission Trading System. Independent greenhouse gases verification bodies should be established to meet the requirements of IAF and PAC. It is necessary to revise the qualification criteria for the verification of the greenhouse gas verification body according to international standards requirements. It is necessary to support the role of accreditation bodies of domestic greenhouse gas verification bodies. It is required to join international organizations of international mutual recognition of international trade and the need for pilot projects to link greenhouse gas emissions. The core link to our emission trading system is called EU-ETS, and we will need to join the IAF/PAC GHG MLA GHG. The International Mutual Recognition Agreement (IAF) is expected to allow international interoperability of GHG emissions verification between EA and the PAC. By signing a PAC GHG MLA, it will need to be prepared to prepare for the pilot project to link the emission trading system.