• Title/Summary/Keyword: Efficiency enhancement

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Enhanced Light Harvesting from F$\ddot{o}$rst-type resonance Energy Transfer in the Quasi-Solid State Dye-Sensitized Solar Cells (F$\ddot{o}$rst energy transfer 를 적용한 준고체 DSSC 의 효율향상)

  • Cheon, Jong Hun;Lee, Jeong Gwan;Yang, Hyeon Seok;Kim, Jae Hong
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.117.1-117.1
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    • 2011
  • We have demonstrated Forst-type resonance energy transfer (FRET) in the quasi-solid type dye-sensitized solar cells between organic fluorescence materials as an energy donor doped in polymeric gel electrolyte and ruthenium complex as an energy acceptor on surface of $TiO_2$. The strong spectral overlap of emission/absorption of energy donor and acceptor is required to get high FRET efficiency. The judicious choice of energy donor allows the enhancement of light harvesting characters of energy acceptor in quasi-solid dye sensitized solar cells which increase the power conversion efficiency. The enhanced light harvesting effect by the judicious choice/design of the fluorescence materials and sensitizing dyes permits the enhancement of photovoltaic performance of DSSC.

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Efficiency Enhancement in Sheet Metal Forming Analysis with a Mesh Regularization Method (격자 정방형화 방법을 이용한 박판 성형해석의 효율개선)

  • Yoon, J.H.;Huh, H.
    • Transactions of Materials Processing
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    • v.12 no.4
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    • pp.401-407
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    • 2003
  • This paper newly proposes a mesh regularization method for the enhancement of the efficiency in sheet metal forming analysis. The regularization method searches for distorted elements with appropriate searching criteria and constructs patches including the elements to be modified. Each patch is then extended to a three-dimensional surface in order to obtain the information of the continuous coordinates. In constructing the surface enclosing each patch, NURBS(Non-Uniform Rational B-Spline) surface is employed to describe a three-dimensional free surface. On the basis of the constructed surface, each node is properly arranged to form unit elements as close as to a square. The state variables calculated from its original mesh geometry are mapped into the new mesh geometry for the next stage or incremental step of a forming analysis. The analysis results with the proposed method are compared to the results from the direct forming analysis without mesh regularization in order to confirm the validity of the method.

Second Harmonic Generation of Low Power Laser Diode Using a Ring Enhancement Cavity (고리형 Enhancement Cavity 를 이용한 저출력 반도체 레이저의 제2조화파 발생)

  • 오차환
    • Korean Journal of Optics and Photonics
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    • v.4 no.2
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    • pp.206-211
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    • 1993
  • We carried out the second harmonic generation of low power CW laser diode with maximum power of 30 mW in $LilO_3$ crystals. We used a ring enhancement cavity to increase the second harmonic conversion efficiency. The ring enhancement cavity was Composed of two flat mirrors and two concave mirrors. The focal length of concave mirrors was 25 mm, and 5 mm long and 10 mm long $LilO_3$ crystals were used. We measured the second harmonic power according to the pumping power and compared with theoretical value. We obtained 397 nm second harmonic power of about $6.6{\mu}W$ in 10 mm long $LilO_3$ crystal with the fundumental 794 nm pumping power of 28 mW.

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Study on Evaluation of Energy Efficiency Rating of the Buildings (건축물의 에너지효율등급 평가에 관한 연구)

  • Son, Won-Tug;Choi, Young-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.15 no.3
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    • pp.65-69
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    • 2012
  • Since 2010, enhancement of the building energy efficiency and certification system and public office building should have been acquiring the first grade of Building Energy Efficiency. The Building Energy Efficiency Rating evaluation tool and Dynamic Analysis Energy simulation program for Building Energy Efficiency are widely used. The suitability to those programs have been discussed as a variety of programs have been used accordingly. In this study, evaluated the characteristic of Building Energy Efficiency Rating tool(ECO2) of the business building. At a result, the variables on the Weather Data, building Profile and building Load property in hourly between those Building Energy Efficiency evaluation tools have different.

Removal of Heavy Metal Contaminants from Cohesive Soil by Electrokinetics (Electrokinetic 기술에 의한 점성토의 중금속 오염물 제거)

  • 정하익;강병희
    • Geotechnical Engineering
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    • v.13 no.6
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    • pp.123-138
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    • 1997
  • Electroosmotic tests were performed on saturated marine clay specimens contaminated with lead to investigate the efficiency of the electrokinetic technique for removal of heavy metals from the cohesive soils. For this purpose, testing program included variable conditions such as the concentration of lead (500, 5, 000, 50, 000mg/kg), the level of electrical current (10, 50, 100 mA), operating duration (5, 15, 30days), and the application of three dirtferent chemicals for enhancement in efficiency. The pH of inflow and outflow, electroosmotic flow and electrical conductivity during the test, and the pH and the concentration of lead across the specimen after the test are presented. Test results came to the conclusion that the electrokinetic technique was very effective to remove heavy metals such as lead from the contaminated cohesive soil. Adding ecetic acid at the cathod to dissolve the procipitates of lead hydroxide as found to be effective for the enhancement of the efficiency in remediation.

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Optical Characteristics of LGP with Nanometer-patterned Grating (나노미터 패턴 회절격자 도광판의 광특성)

  • Hong, Chin-Soo;Kim, Chang-Kyo;Lee, Byoung-Wook;Lee, Myoung-Rae
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.4
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    • pp.353-360
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    • 2008
  • The LGP with nanometer structures resulted in enhancement of optical efficiency. Its fundamental mechanism is to recycle the polarized light via one round-trip through QWP(Quarter-Wave Plate) but the maximum efficiency to reach with this method is limited up to 2. To get the larger efficiency than this limited one a LGP with nanometer-patterned grating is suggested. For its optimum design the computer simulation is performed and suggests a grating that the spatial frequency between adjacent patterns is 500nm, its height 250nm, duty cycle 50%, and its cross section is rectangular. On the basis of simulation results the LGP with nanometer-patterned grating is fabricated and its optical properties such as angular intensity distribution and CIE color coordinates are characterized. The angles of transmitted light are nearly the same as the results expected from the generalized Snell's law. Thus the Mathematica code, developed in this experiment, will be applied to designing the optimized LGP. The LGP with nanometer-patterened grating shows the enhancement of transmitted intensity distribution up to 4.9 times.