• Title/Summary/Keyword: new chemicals

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Environmental Biosensors for Organochlorines, Cyanobacterial Toxins and Endocrine Disrupting Chemicals

  • Sadik, Omowunmi A.;Ngundi, Miriam M.;Yan, Fei
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.6
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    • pp.407-412
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    • 2000
  • Environmental biosensors and related techniques for monitoring organochlorines, endocrine disrupting chemicals and cyanobacterial toxins are described. The practical requirements for an ideal environmental biosensor are analyzed. Specific case studies for environmental applications are reported for triazines, chlorinated phenols, PCBs, microcystins, and endocrine disrupting chemicals. A new promising approach is reported for microcystins and alkylphenols that utilize electrooptical detection.

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Reactive Mesogen Mixtures for Integrated Optical Films

  • Lee, Hee-Kyu;Lee, Seung-Eun;Cumming, S.A.;Verrall, M.;Parri, O.;Harding, R.;Marden, S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.266-269
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    • 2003
  • TFT LCD mode has some well-documented performance limitations, namely limited viewing angle, inversion of the gray scale levels and poor luminance efficiency because of the necessity of using crossed polarisers attached to the display cell. During the last few years many initiatives have been undertaken to solve these problems by incorporation birefringent films of various designs into the LCD module. Controlling the optical performance of LCDs often requires combination of liquid crystal material properties, cell parameters and optical films. Such optical films have traditionally been made with stretched polymer materials such as polycarbonate, but recently coated liquid crystalline materials have been used to give improved optical films which can greatly enhance the performance of LCDs. We have now developed reactive mesogen materials to add ultra-thin optical layers into the display structure, and these allow the potential for many new applications.

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Biaxial integrated optical film for VA mode LCD's made from in-situ photopolymerised reactive mesogens.

  • Kim, Kyeong-Hyeon;Lyu, Jae-Jin;Chung, Dong-Hoon;Verrall, M.;Slaney, K.;Perrett, T.;Parri, O.;Lee, Seung-Eun;Lee, Hee-Kyu
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.773-775
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    • 2004
  • For high end, large area displays, all current LC modes require some degree of optical compensation to improve the front of screen viewing experience. Currently most optical films are laminated to the outside of the LCD cell, between the glass and polariser. In this paper we wish to show how it is possible to integrate the compensating optical film within a VA mode LCD cell. The paper will describe the process of making the biaxial film through the process of in-situ photopolymerisation of an aligned film of reactive mesogens in the cholesteric phase using polarised UV light. The film can be made on the colour filter array side of the LCD panel. In addition the process of fabricating a VA mode LCD containing this film will be described and the performance of this module will be presented

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Biaxial Integrated Optical Film for VA Mode LCD's Made from In-situ Photopolymerised Reactive Mesogens

  • Kim, Kyeong-Hyeon;Lyu, Jae-Jin;Chung, Dong-Hoon;Verrall, M;Slaney, K;Perrett, T;Parri, O;Lee, Seung-Eun;Lee, Hee-Kyu
    • Journal of Information Display
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    • v.5 no.2
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    • pp.23-26
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    • 2004
  • For high end, large area displays, all current LC modes require some degree of optical compensation to improve the front of screen viewing experience. Currently most optical films are laminated to the outside of the LCD cell, between the glass and polariser. In this paper we wish to show how it is possible to integrate the compensating optical film within a VA mode LCD cell. The paper will describe the process of making the biaxial film through the process of in-situ photopolymerisation of an aligned film of reactive mesogens in the cholesteric phase using polarised UV light. The film can be made on the colour filter array side of the LCD panel. In addition the process of fabricating a VA mode LCD containing this film will be described and the performance of this module will be presented.

Effect of Extraction Solvent on the Separation of Sulfur Components in Light Cycle Oil (접촉분해경유로부터 산화황화합물의 분리에 관한 추출용매의 영향)

  • Park, Su-Jin;Jeong, Kwang-Eun;Chae, Ho-Jeong;Kim, Chul-Ung;Jeong, Soon-Yong;Koo, Kee-Kahb
    • Korean Chemical Engineering Research
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    • v.46 no.5
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    • pp.965-970
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    • 2008
  • The separation of sulfone components using light cycle oil(LCO) after oxidation was carried out by solvent extraction method using various polar solvents such as water, n-methyl-2-pyrrolidone(NMP), dimethyl sulfoxide, ethyl acetate, acetonitrile, dimethyl formamide, and methyl alcohol. It was found that phase separation between LCO layer and solvent occurred under mixed solvent adding a proper amount of water. The mixture solvent of NMP and water was a promising extraction solvent due to the selective removal and high distribution coefficient of sulfone component in LCO. 99.5% over of sulfur contents in LCO can be removed by 4 stages equilibrium extraction.

Risk Assessment in OECD High Production Volume Chemicals Program and its Countermeasure (OECD 대량생산화학물질 위해성평가 및 대책)

  • Kim, Myungjin;Bae, Heekyung;Choi, Yeonki;Kim, Mi Kyoung;Koo, Hyun-Ju;Song, Sang-Hwan;Choi, Kwang-Soo
    • Journal of Environmental Impact Assessment
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    • v.14 no.5
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    • pp.347-353
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    • 2005
  • The risk assessment is the qualitative or quantitative evaluation of the risk posed to human health and the environment by the actual or potential presence or release of hazardous substances, pollutants or contaminants. The environmental impact assessment (EIA) is assessed by the environmental criteria, and risk assessment is assessed by the risk rate. Risk rate based on dose-response values may not be easy to apply on regulatory basis like EIA for uncertainty. Internationally there is an example of OECD program. Risk assessment of High Production Volume (HPV) Chemicals has started since the OECD Program with the 1990 Council Act on the Co-operative Investigation and Risk Reduction of Existing Chemicals. These HPV chemicals include all chemicals produced or imported at levels greater than 1,000 tonnes per year in at least one Member country or in the European Union region. The SIDS called the Screening Information Data Set is regarded as the minimum information needed to assess an HPV chemical to determine whether any further work should be carried out or not. All the data elements of SIDS including assessment for environment and health are prepared as three formats of the full SIDS Dossier, the SIDS Initial Assessment Report (SIAR), and the SIDS Initial Assessment Profile (SIAP) of an HPV chemical. In 1998 the global chemical industry through the International Council of Chemical Associations (ICCA) has joined to work with OECD. The OECD has assessed approximately 1,000 chemicals from 1991 through 2004 with ICCA. Till the February of 2005, 592 chemicals of those chemicals completed SIDS reports. Member countries have been targeted the goal of 1,000 new chemicals from 2005 to 2010 and Korea shared 36 chemicals from the 1,000 new chemicals. Currently Korea has completed SIDS reports of 7 chemicals among sponsored 24 chemicals. In conclusion SIDS project will be linked to national program for outputs application with more reliable production. Both the OECD and industry will carry out their commitment to complete assessments for more and the remaining chemicals assessment. The major outputs will contribute to cope with international chemical management.

Analysis and management of new hazard chemicals in foods (식품 중 신종유해물질의 관리 및 분석)

  • Choi, Dongmi;Hu, Soojung;Suh, Junghyuck;Yoon, Taehyung;Kim, Eunju;Choi, Jangduck;Park, Sung-Kug;Lee, Kwangho
    • Analytical Science and Technology
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    • v.22 no.2
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    • pp.172-185
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    • 2009
  • To help understanding about hazard chemicals occurring newly in food, it has been reviewed characteristics, mechanism, food standards and analytical trend of the hazard chemicals occurring avoidably in food manufacturing process. The new hazard chemicals in food are classified by 4 regarding mechanism such as heat, fermentation, additives and unknowns. The new hazard chemicals by heat process are acrylamide, furan, HCAs and PAHs. By the fermentation, ethylcarbamate and biogenic amines are occurred. According to food additives, 3-MCPD, benzene and nitrosamines can be produced. And the last group is the illegal compounds including anti-impotence drug analogues and anti-obesity drug analogues. To analyze the new hazard chemicals in food, GC or LC with UVD, FLD or MSD are used mainly after sample pretreatment by LLE, SPE or headspace method.