• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.28 no.5
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• pp.359-367
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• 1999

최근 10년 동안 우리들은 성층권의 오존층 고갈(depletion of ozone layer), 지구온난화(global warming) 및 산성비(acid rain) 등을 포함하는 지구환경문제를 해결하여야 하는 많은 도전을 받고 있다. 몬트리올조약과 Montreal Protocol)이 수정되어 특정 CFC계 냉매들의 생산삭감계획이 앞당겨짐에 따라 우리들은 조속히 이들 문제를 해결해야될 심각한 국면에 직면하고 있다.

• Journal of Information Display
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• v.11 no.3
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• pp.113-118
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• 2010

The effect of hydrogen in the alumina gate insulator on the bottom gate oxide thin film transistor (TFT) with an InGaZnO film as the active layer was investigated. TFT with more H-containing alumina films (TFT A) fabricated via atomic layer deposition using a water precursor showed higher stability under positive and negative bias stresses than that with less H-containing alumina deposited using ozone (TFT B). While TFT A was affected by the pre-vacuum annealing of GI, which resulted in $V_{th}$ instability under NBS, TFT B did not show a difference after the pre-vacuum annealing of GI. All the TFTs showed negative-bias-enhanced photo instability.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.56-56
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• 2010

We report a low-temperature fabrication of organic/inorganic nanohybrid dielectrics for organic thin film transistors. The self-assembled organic layers (SAOLs) were grown by repeated sequential adsorptions of C=C-terminated alkylsilane and metal (Al or Ti) hydroxyl with ozone activation, which was called "molecular layer deposition (MLD)". The $TiO_2$ and $Al_2O_3$ inorganic layers were grown by ALD, which relies on sequential saturated surface reactions resulting in the formation of a monolayer in each sequence and is a potentially powerful method for preparing high quality multicomponent superlattices. The MLD method combined with ALD (MLD-ALD) was applied to fabricate SAOLs-$Al_2O_3$-SAOLs-$TiO_2$ nanohybrid superlattices on polymer substrates at relatively low temperature. The MLD method is an ideal fabrication technique for various flexible electronic devices.

• Journal of the Korean Institute of Gas
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• v.9 no.1 s.26
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• pp.16-20
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• 2005

CFC-11 and HCFC-l4lb have been used as blowing agents for rigid polyurethane foam insulation of LNG storage tank. But CFC-11 and HCFC- l4lb deplete ozone layer in the stratosphere. So in leading countries, the use of CFC-11 has been prohibited since 1995 and the use of HCFC-l4lb will be prohibited from 2005. Much efforts and studies have been done about alternative blowing agents and insulations blown by alternative blowing agents. This paper deals with polyurethane foams (PUFs) blown by HFC-365mfc, shows their physical and mechanical characteristics and thermal performance. These data are compared with the results of PUFs blown by HCFC-l4lb. From these test results, PUFs blown by HFC-365mfc show good mechanical and thermal characteristics. It is possible to use PUFs blown by HFC-365mfc as main insulation of membrane type LNG storage tank.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.12
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• pp.615-641
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• 1999

Trade and the environment emerged as a major and complex issue for trade negotiators in the final stages of the Uruguay Round negotiations. The agreements and other international measures employing trade measures and trade sanctions for achieving global environmental objectives are Vienna Convention on the Protection of the Ozone Layer(1985), the Montreal Protocol on Substances that deplete the Ozone Layer(1987), The Framework Convention on Climate Change(1992), the Convention on Biological Diversity(1992), the Basel Convention on the Control of Transboundary Movement of Hazardous Waste and their Disposal(1992), the Convention on International Trade in Endangered Species of Wild Faunna and Flora(1975), the Rio Declaration, the Agenda 21, etc. The texts of the World Trade Organization(WTO) incorporated certain provisions which were designed to reflect some of the environmental concerns are Trade-Related Aspects of Intellectual Properity Rights(TRIPs), Trade-Related Investment Measures (TRIMs), the General Agreement on Trade in Services(GATS), and Technical Barriers to Trade(TBT) There is the possibility of conflict between multilateral environmental agreements and WTO agreements granting waivers against trade measures and sanctions. This remains a possibility, especially between countries which are Member of WTO and which are not Members of the relevant multilateral environment agreements, and countries which are Members of both the WTO and the relevant MEAs. Measures taken under the trade-related provisions of MEAs could potentially give rise to conflicts under obligations arising in WTO texts. If the parties in dispute are WTO members while they are not members of MEAs, the WTO provisions can be granted a certain priority in terms of international norms and vice versa. When the parties concerned are both WTO members and MEAs, it will be rational to grant the WTO provisions a priority. However, such measures should neither constitute a means of arbitrary or unjustifiable discrimination between countries where similar conditions prevail, nor create a disguised restriction on trade. Also any trade measures taken should be necessary to prevent developments in trade from endangering the effectiveness of an MEA and they should be proportional and least trade restrictive.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.304-304
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• 2010

The study on the catalytic oxidation of carbon monoxide (CO) to carbon dioxide ($CO_2$) using the noble metals has long been the interest subject and the recent progress in nanoscience provides the opportunity to develop new model systems of catalysts in this field. Of the noble metal catalysts, we selected ruthenium (Ru) as metal catalyst due to its unusual catalytic behavior. The size of colloid Ru NPs was controlled by the concentration of Ru precursor and the final reduction temperatures. For catalytic activity of CO oxidation, it was found that the trend is dependent on the size of Ru NPs. In order to explain this trend, the surface oxide layer surrounding the metal core has been suggested as the catalytically active species through several studies. In this poster, we show the influence of surface oxide on Ru NPs on the catalytic activity of CO oxidation using chemical treatments including oxidation, reduction and UV-Ozone surface treatment. The changes occurring to UV-Ozone surface treatment will be characterized with XPS and SEM. The catalytic activity before and after the chemical modification were measured. We discuss the trend of catalytic activity in light of the formation of core-shell type oxide on nanoparticles surfaces.

• Asian Journal of Atmospheric Environment
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• v.9 no.4
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• pp.259-271
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• 2015

This study conducted analyses on biogenic volatile organic compounds (BVOC) emission sources contributing to urban ozone ($O_3$) concentration in Osaka Prefecture, Japan in summer 2010 by using the Weather Research and Forecasting model (WRF) version 3.5.1 and the Community Multiscale Air Quality model (CMAQ) version 5.0.1. This prefecture is characterized by highly urbanized area with small forest area. The contributions of source regions surrounding Osaka were estimated by comparing the baseline case and zero-out cases for BVOC emissions from each source region. The zero-out emission runs showed that the BVOC emissions substantially contributed to urban $O_3$ concentration in Osaka (10.3 ppb: 15.9% of mean daily maximum 1-h $O_3$ concentration) with day-by-day variations of contributing source regions, which were qualitatively explained by backward trajectory analyses. Although $O_3$ concentrations were especially high on 23 July and 2 August 2010, the contribution of BVOC on 23 July (35.4 ppb: 25.6% of daily maximum $O_3$) was much larger than that on 2 August (20.9 ppb: 14.2% of daily maximum $O_3$). To investigate this difference, additional zero-out cases for anthropogenic VOC (AVOC) emissions from Osaka and for VOC emissions on the target days were performed. On 23 July, the urban $O_3$ concentration in Osaka was dominantly increased by the transport from the northwestern region outside Osaka with large contribution of $O_3$ that was produced through BVOC reactions by the day before and was retained over the nocturnal boundary layer. On 2 August, the concentration was dominantly increased by the local photochemical production inside Osaka under weak wind condition with the particularly large contribution of AVOC emitted from Osaka on the day.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.1 no.1
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• pp.19-33
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• 1997

The high oxidants, which occur the daily maximum concentrations in the afternoon, are transported into the other region via long range transport mechanisms or trapped within the shallow mixing boundary layer and then removed physically (deposition, transport by mountain wind, etc.) and chemically (reaction with local sources). Therefore, modeling formation of photochemical oxidants requires a complex description of both chemical and meteorological processes. In this study, as a part of air quality studies, we reviewed various aspects of photochemical modeling on the basis of currently available literature. The result of the review shows that the model is based on a set of coupled continuity equations describing advection, diffusion, transport, deposition, chemistry, emission. Also photochemical oxidant models require a large amount of input data concerned with all aspects of the ozone life cycle. First, emission inventories of hydrocarbon and nitrogen oxides, with appropriate spatial and temporal resolution. Second, chemical and photochemical data allowing the quantitative description of the formation of ozone and other photochemically-generated secondary pollutants. Third, dry deposition mechanisms particularly for ozone, PAN and hydrogen peroxide to account for their removal by absorption on the ground, crops, natural vegetation, man-made and water surfaces. Finally, meteorological data describing the transport of primary pollutants away from their sources and of secondary pollutants towards the sensitive receptors where environmental damage may occur. In order to improve our present study, shortcomings and limitation of existing models are pointed out and verification process through observation is emphasized.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.6
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• pp.791-804
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• 2011

Numerical simulations were carried out to investigate the impact of PBL (Planetary boundary layer) scheme implemented in WRF on the result of meteorological fields and CMAQ modeling. 25-day period, representing high ozone concentration, was selected for the simulations. The three WRF domains covered East Asia region, Korean Peninsula and Seoul metropolitan area. The sensitivity of WRF-CMAQ modeling to the various PBL schemes was assessed and quantified by comparing model output and against observation from the meteorological and the air quality monitoring network within the domain. The meteorological variables evaluated included temperature, wind speed and direction over surface sites and upper air sounding sites. The CMAQ variables included gaseous species $O_3$ and $NO_x$ over monitoring stations. Although difference of PBL schemes implemented in WRF, they did not appreciably affect the WRF and CMAQ performance. There are partially differences between non-local and local mixing scheme, but are not distinct differences for the results of weather and air quality. It is suggested that impact of parameterization of vertical eddy diffusivity scheme in CMAQ also need to be researched in the future study.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.6
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• pp.102-108
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• 2001

To prevent green house effect and destruction of an ozone layer, an ozone destruction potential(OBP) must be zero and a refrigerant for low global warming potential(GWP) is needed. HFC-l34a, in which hydrogen is mixed instead of chlorine is a refrigerant used for automobile conditioners and its destruction potential is ecologically zero. However, it is not consid- ered as a perfect substitutive refrigerant as its GWP is high. It is studied refrigerant mixtures in which HFC-l52a and $CF_3 I$ in HFC-l52a with low GWP and zero ODP are mixed by experimentally and concluded as follows: 1) With the variation of speed of compressor outside temperature and flow rate, 7he heat of evaporator and compressor and coefficient of perfor- mance was varied, and influenced the air conditioner. 2) The pressure of evaporator was decreased with increasing the speed of compressor and the pressure of evaporator with the refrigerant HFC-l52a was higher 24% than that of azotrope refrigerant mixed with $CF_3 I$