• Title/Summary/Keyword: DRE

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Decomposition Characteristics of Non-Degradable Liquid Waste under High Temperature and High Pressure Conditions (고온 고압 조건에서의 난분해성 액상폐기물 분해 특성)

  • Lee, Gang-Woo;Shon, Byung-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.6
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    • pp.1572-1578
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    • 2007
  • The specified wastes consist of waste acid, waste alkali, waste oil, waste organic solvent, waste resin, dust, sludge, infectious waste, and others. Among these specified wastes, a great portion is liquid phase wastes. The purpose of this study is to develop the high temperature and high pressure (HTHP) treatment system for decomposition of the liquid phase specified waste (LPSW). For this, we analyzed the physical and chemical properties of the LPSW such as density, proximate analysis, ultimate analysis, heating values, and designed 0.3 ton/day HTHP treatment system. The LPSW tested in this experiment were prepared by adding TCE(trichloroethylene) and toluene to liquid phase waste which was brought into the commercial waste treatment company. The average density of waste oil (25 samples), waste resin (5 samples), and waste solvent (12 samples) was 0.99 g/mL, 0.91 g/mL, and 0.93 g/mL, respectively. And the average lower heating value of waste oil, waste resin, and waste solvent was 8,294 kcal/kg, 5,809 kcal/kg, and 7,462 kcal/kg, respectively. The DRE (Destruction & Removal Efficiency) of TCE and toluene were 99.95% and 99.73% at atmospheric pressure conditions and that were 99.99% and 99.82% at pressurized conditions, respectively. These results showed that TCE/toluene mixtures were properly decomposed over about 99.73% of DRE by the HTHP treatment system and pressurized conditions were more effective to destroy those pollutants than atmospheric pressure conditions. Also these systems could be directly applied to industries which try to treat the liquid phase specified waste within the regulation limit.

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The progress in NF3 destruction efficiencies of electrically heated scrubbers (전기가열방식 스크러버의 NF3 제거 효율)

  • Moon, Dong Min;Lee, Jin Bok;Lee, Jee-Yon;Kim, Dong Hyun;Lee, Suk Hyun;Lee, Myung Gyu;Kim, Jin Seog
    • Analytical Science and Technology
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    • v.19 no.6
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    • pp.535-543
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    • 2006
  • Being used widely in semiconductor and display manufacturing, $NF_3$ is internationally considered as one of the regulated compounds in emission. Numerous companies have been continuously trying to reduce the emissions of $NF_3$ to comply with the global environmental regulation. This work is made to report the destruction and removal efficiency (DRE) of electrically heated scrubbers and the use rate in process chambers installed in three main LCD manufacturing companies in Korea. As the measurement techniques for $NF_3$ emission, mass flow controlled helium gas was continuously supplied into the equipment by which scrubber efficiency is being measured. The partial pressures of $NF_3$ and helium were accurately measured for each sample using a mass spectrometer, as it is emitted from inlet and outlet of the scrubber system. The results show that the DRE value for electrically heated scrubbers installed before 2004 is less than 52 %, while that for the new scrubbers modified based on measurement by scrubber manufacturer has been sigificentely improved upto more than 95 %. In additon, we have confirmed the efficiency depends on such variables as the inlet gas flow rate, water content, heater temperature, and preventative management period. The use rates of $NF_3$ in process chambers were also affected by the process type. The use rate of radio frequency source chambers, built in the $1^{st}$ and $2^{nd}$ generation process lines, was determined to be less than 75 %. In addition, that of remote plasma source chambers for the $3^{rd}$ generation was measured to be aboove 95 %. Therefore, the combined application of improved scrubber and the RPSC process chamber to the semiconductor and display process can reduce $NF_3$ emmision by 99.95 %. It is optimistic that the mission for the reduction of greenhouse gas emission can be realized in these LCD manufacturing companies in Korea.

An analysis of the Impact of Policies Toward the Urbar Poor (도시 저소득층 생활안정 대책의 효과분석)

  • 남성일;김경환
    • Journal of the Korean Regional Science Association
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    • v.9 no.2
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    • pp.59-69
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    • 1993
  • This paper empirically analyzes economic impacts of policy instruments and suggests policy alternations to improve the urban poor's alternatioes to improve the urban poor's standard of living in Korea. By estimating a joint decsim model of hours of work and housing demand utilizing a sample of 270 urban poor housholds, the study finds that the efects of policies dre diverse. The dncome subsidy to msst effectwe in increasing comsumption while the wage increase is least likely to decrease hours of work. Policy suggection are firstly that policies to ward the urban poor should hot be overlapping or contradictory, and secondly that the policies should be able to increase the poor's wage earning abiliby.

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Estimation Properties of Kalman Filter for the System with Unobservable Bias (관측 불가능한 바이어스가 있는 시스템의 칼만필터 추정특성)

  • Song, Gi-Won;Lee, Sang-Jeong
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.10
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    • pp.874-881
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    • 2001
  • By showing the existence of the ARE solution and the convergence property of the DRE solution, this paper proves that a Kalman filter for the linear system with the unobservable bias is stable. It is also shown that the Kalman filter has a biased steady state estimation error whose covariance is affected mainly by the unobservable bias. Finally, the results are illustrated through a 2nd order system example including the inertial navigation system.

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A Survey of Robotic Technologies for Diagnosis and Treatment of Prostate Cancer (전립선 암 진단 및 치료를 위한 로봇기술 응용 현황)

  • Ahn, Bum-Mo;Park, Ki-Han;Lee, Hyo-Sang;Kim, Jung
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.9
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    • pp.852-859
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    • 2010
  • Robotic techniques can be one of the promised solutions to address the prostate cancer which is one of the most important public health problems in medical fields. Despite several past and on-going dedicated researches, the systematic techniques and completed theories have not been established well. Therefore we review the state-of-the-art literature on the applications of engineering technologies with particular focus on diagnosis and treatment of prostate cancer. The current status of the elastography and systematic DRE are presented as novel diagnostic tools, and an overview of the applied technologies to address the limits of the treatment (radical prostectomy and brachytherapy) is reviewed.

Fabrication of Beta-phase Poly(9,9-dioctylfluorene) Nanowire Arrays for Polymer Light-Emitting Diode Using Direct Printing Method

  • Baek, Jang-Mi;Lee, Gi-Seok;Seong, Myeong-Mo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.560-560
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    • 2012
  • We report a one-step fabrication method of Poly(9,9-dioctylfluorene) (PFO) nanowire array with pronounced ${\beta}$-Phase. We use liquid-bridge-mediated nanotransfer molding (LB-nTM) which is a new direct nano-patterning method based on the direct transfer of various materials from a mold to a substrate via liquid layer. The formation of the ${\beta}$-phase morphology in the resulting PFO nanowire array was evidenced by the presence of an absorption peak at 435nm. With the collection polarizer oriented parallel to the wire long axis, the PL emission was most intense and an emission dichroic ratio, DRE, of 3.7 was determined. The nanowire array have been investigated by scanning electron microscopy (SEM). Also, we simply fabricated structure of device of ITO/PFO nanowire arrays/Al and the electroluminescence spectra were recorded at various applied voltage.

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A Numerical Simulation of Hazardous Waste Destruction in a Dump Incinerator (덤프 소각기에서 유해폐기물 분해에 대한 수치해석)

  • 전영남;정오진;채종성
    • Journal of Korean Society for Atmospheric Environment
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    • v.16 no.6
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    • pp.665-674
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    • 2000
  • A major source of the hazardous waste generated is from chemical industries producing plastics, herbicides, pesticides and chlorinated solvents. All of these processes produce a class if hazardous waste termed the chlorinated hydrocarbons(CHCs), either directly or from undesirable side reactions. In this study, we investigated the destruction characteristics of hazardous waste through incineration. A nonequilibrium combustion model was used to describe the effect of the chemical kinetics due to the flame inhibition characteristics of $CCl_4$ which was used as the surrogate of hazardous waste. A parametric screening studies was made in a dump incinerator proposed in this study. The dump incinerator showed high $CCl_4$ DRE(Destruction and Removal Efficiency) as 5 nines. $CCl_4$/CH$_4$ ratio appeared to be most important in the destruction of $CCl_4$ through incineration.

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Adsorption of Specific Organics in Water on GAC and Regeneration of GAC by Countercurrent Oxidative Reaction

  • Ryoo, Keon-Sang;Kim, Tae-Dong;Kim, Yoo-Hang
    • Bulletin of the Korean Chemical Society
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    • v.23 no.6
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    • pp.817-824
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    • 2002
  • Granular activated carbon(GAC) is highly effective in removing organic compounds which are resistant to biological disintegration in wastewater treatment. However, GAC has reached its full adsorptive capacity, GAC needs to be regenerated before it can be used for a further adsorption cycle. Countercurrent oxidative reaction (COR) technique has been developed and evaluated for the regeneration of spent GAC. Various parameters such as flame temperature, the loss of carbon, destruction and removal efficiency (DRE) of organic compounds, surface area, surface structure, adsorptive capacity, etc. were examined to determine the performance of COR. The results of these tests showed that adosorptive capacity of regenerated GAC was completely recovered, the loss of carbon was controllable, flame temperature was high enough to insure complete destruction and removal $(\geq99.9999%)$ of specific organics of interest, polychlorinated biphenyls (PCBs), that are thermally stable, and on formation of toxic byproducts such as polychlorinated dibenzo-p-dioxins (PCDDs) or polychlorinated dibenzofurans (PCDFs) were detected during the regeneration process. The COR technique is environmentally benign, easy to use and less copital intensive than other available regeneration technologies.

Regulation of Cyp 1A1 Gene Expression by Retinoic Acid Receptor, Retinoid X Receptor and Constitutive Androstane Receptor in Rainbow Trout Hepatoma Cells(Rth 149)

  • Kim, Ji-Sun;Yang, So-Yeun;Seo, Mi-Jung;Sheen, Yhun-Yhong
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2003.10b
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    • pp.136-136
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    • 2003
  • Exposure of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes a variety of biological and toxicology effects, most of which are mediated by aryl hydrocarbon receptor (AhR). The ligand-bound AhR as a heterodimer with AhR nuclear translocator (ARNT) binds to its specific DNA recognition site, the dioxin-responsive element (DRE), and it results in increased transcription of CVP1A1 gene.(omitted)

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THERMAL PLASMA DECOMPOSITION OF FLUORINATED GREENHOUSE GASES

  • Choi, Soo-Seok;Park, Dong-Wha;Watanabe, Takyuki
    • Nuclear Engineering and Technology
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    • v.44 no.1
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    • pp.21-32
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    • 2012
  • Fluorinated compounds mainly used in the semiconductor industry are potent greenhouse gases. Recently, thermal plasma gas scrubbers have been gradually replacing conventional burn-wet type gas scrubbers which are based on the combustion of fossil fuels because high conversion efficiency and control of byproduct generation are achievable in chemically reactive high temperature thermal plasma. Chemical equilibrium composition at high temperature and numerical analysis on a complex thermal flow in the thermal plasma decomposition system are used to predict the process of thermal decomposition of fluorinated gas. In order to increase economic feasibility of the thermal plasma decomposition process, increase of thermal efficiency of the plasma torch and enhancement of gas mixing between the thermal plasma jet and waste gas are discussed. In addition, noble thermal plasma systems to be applied in the thermal plasma gas treatment are introduced in the present paper.