• Journal of Korean Society for Atmospheric Environment
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• 제19권E3호
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• pp.137-148
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• 2003

In this study, we examined the influence of long-range transport of dust particles and air pollutants on the photochemistry of NO$_3$on Jeju Island, Korea (33.17 N, 126.10$^{\circ}$E) during the Asian Dust-Storm (ADS) period of April 2001. Three ADS events were observed during the periods of 10∼12, 13∼14, and 25∼26 April. Average concentration level of nighttime NO$_3$on Jeju Island during the ADS period was estimated to be about 2 x 10$^{8}$ molecules cm$^{-3}$ ( - 9 pptv). Decreases in NO$_3$levels during the ADS period was likely to be determined mainly by the enhancement of the $N_2$O$_{5}$ heterogeneous reaction on dust aerosol surfaces. The reaction of N20s on aerosol surfaces was a more important sink for nighttime N03 during the ADS due to the significant loading of dust particles. The reaction of $N_2$O$_{5}$ with NMHCs and the gas-phase reaction of N20s with water vapor were both significant loss mechanisms during the study period, especially during the NADS. However, dry deposition of these oxidized nitrogen species and a heterogeneous reaction of NO$_3$were of no importance. Short-term observations of $O_3$, NO$_2$, DMS, and SO$_2$in the MBL indicated that concentrations of most of these chemical species were different between the ADS and non - Asian - Dust-Storm (NADS) periods, implying that their levels were affected sensitively by the differences in air mass trajectories.

• 품질경영학회지
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• 제43권3호
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• pp.359-372
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• 2015

Purpose: Through studying the expert's and non-experts panel responses to the questions regarding the attributes of chemical-biological protection cloth quality in terms of the levels of customer demand and technical factors has been studied. We are applied to a QFD matrix with find out the relationship between the selective removal efficiency of chemical-biological cloth and the guidelines of technical approach. Methods: We fabricated several composite of ion-exchange resins with selectively permeable performance designed to facilities water vapor transport and selective adsorption of the harmful gases. With these materials, we characterized on the selectively permeable performance to identify ion-exchange resin with chemical-biological protective cloth. Results: Results showed that ion exchange materials possessed performance with selectively efficiencies as NH3, SOx, NOx and HCl gas. The selective adsorption amount of ammonia and hydrogen gases were $90-80{\mu}g/g$ with TRILITE SCR-BH sulfonated ion exchange resin. The PP non-woven/ion exchange resin adsorbent materials possessed performance with water vapor permeability were 1,100-1,350 g/m2/day, it's was two times high value compare with activated carbon. With these materials, we characterized selectively removal efficiency to identify new ion-exchange material with chemical-biological protective capability. Conclusion: This study shows that a QFD aids in deciding with of the adsorption parameters to optimized with chemical-biological protection cloth manufacturing.

• 한국측량학회지
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• 제29권6호
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• pp.553-559
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• 2011

자동차 보유대수 증가에 따른 고유가와 온실가스 배출로 자전거이용의 중요성이 대두되고 있지만, 자전거이용률은 현저하게 낮은 실정이다. 자전거이용 활성화를 위한 대책으로 전국자전거도로 사업이 진행되고 있으며 각 지방자치단체에서도 자전거도로 기본계획을 수립하여 진행되고 있다. 노선 선정에 대한 연구가 활발히 진행되고 있지만, 자료 처리에 대한 연구는 명확한 결과를 도출하기엔 부족한 실정이다. 자전거도로 설계 기준에 명시되어진 종단경사도 지형상황 등으로 인하여 부득이하다고 인정되는 경우에는 예외로 한다고 되어 있다. 본 연구에선 기존 자전거도로가 여수시의 지형상황을 고려하여 개설되어 졌는지, 종단경사 기준을 고려하여 연결 가능한 자전거도로 노선 선정을 제시했다. 추가요소로 차선 수, 도로 폭을 포함시켜 개설 가능한 자전거도로 중 적합한 자전거도로 노선이 산출되었다. 향후 산지가 많은 지역을 대상으로 자전거도로 선정 시 종단경사 기준의 활용 방안으로 이용될 것이다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.454-454
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• 2011

Graphene shows unusual electronic properties, such as carrier mobility as high as 10,000 $cm^2$/Vs at room temperature and quantum electronic transport, due to its electronic structure. Carrier mobility of graphene is ten times higher than that of Silicon device. On the one hand, quantum mechanical studies have continued on graphene. One of them is quantum Hall effect which is observed in graphene when high magnetic field is applied under low temperature. This is why two dimension electron gases can be formed on Graphene surface. Moreover, quantum Hall effect can be observed in room temperature under high magnetic field and shows fractional quantization values. Quantum Hall effect is important because quantized Hall resistances always have fundamental value of h/$e^2$ ~ 25,812 Ohm and it can confirm the quantum mechanical behaviors. The value of the quantized Hall resistance is extremely stable and reproducible. Therefore, it can be used for SI unit. We study to measure quantum Hall effect in CVD graphene. Graphene devices are made by using conventional E-beam lithography and RIE. We measure quantum Hall effect under high magnetic field at low temperature by using He4 gas closed loop cryostat.

• 한국염색가공학회지
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• 제21권1호
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• pp.1-9
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• 2009

A lot of research has been made over the recent decade to develop testing packages with antimicrobial properties to improve food safety. In this study, a new method, experimental device and technology for environmental corresponding packages of polypropylene (PP) film has been developed to provide effective temperature buffering during the transport/long-term storage of grains or foodstuffs from the supplier to the market. This quantitatively optimized mixing system enabled to produce PP films with the 700$\sim$1,400d (width;1.5$\sim$3mm, thickness;0.01$\sim$0.5mm). In the whole mixing systems, the finely-granulated inorganic illite and PP virgin chip for master batch (M/B) chip was calculated by digital measurement methods, and then the M/B chip for PP film was adapted through a air jet and PP grinding method. The prepared PP film was characterized with tensile strength and elongation, far infrared radiation (FIR) emissivity, antimicrobial activity and deodorization properties. The results revealed that the two differently grain-sized illite could be show homogeneously dispersed on PP chip surface, and as the increasing of illite content, the FIR emissivity and the anion emission rate of film was increasingly improved. In both of 325 and 1,500 mesh-sized illite contained PP chip, of course the antimicrobial activity was good. But the ultimate deodorization rate for ammonia gas of PP film were found to be approximately the same.

• 한국자동차공학회논문집
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• 제17권1호
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• pp.137-145
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• 2009

The steady-state kinetics of the selective catalytic reduction (SCR) of $NO_X$ with $NH_3$ has been investigated over a commercial ${V_2}{O_5}/TiO_2$ catalyst. In order to account for the influence of transport effects the kinetics are coupled with a fully transient two-phase 1D+1D monolith channel model. The Langmuir-Hinshelwood (L-H) mechanism is adopted to describe the steady-state kinetic behavior of the ${V_2}{O_5}/TiO_2$ catalyst. The reaction rate expressions are based on previously reported papers and are modified to fit the experimental data. The steady-state chemical reaction scheme used in the present mathematical model has been validated extensively with experimental data of selective $NO_X$ reduction efficiency for a wide range of inlet conditions such as space velocity, oxygen concentrations, water concentration, and $NO_2/NO$ ratio. The parametric investigations are performed to examine how the $NH_3$ slip from a SCR $DeNO_X$ catalyst and the conversion of $NO_X$ are affected by the reaction temperature, $NH_3/NO_X$ feed ratio, and space velocity for feed gas compositions with $NO_2/NO_X$ ratios of 0 and 0.5.

• 대한공간정보학회지
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• 제20권4호
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• pp.3-9
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• 2012

화석연료 사용의 급격한 상승은 연료의 고갈과 막대한 온실가스배출을 초래했다. 특히, 건설 분야는 전체 이산화탄소 배출량의 약 1/4 이상을 차지하는 환경문제의 원천이다. 이에 본 연구에서는 건설 현장의 탄소배출량 감소를 위한 GIS기법의 적용 강화를 목표로 사토장 선정에 네트워크분석기법을 적용하였다. 그 결과 후보지별로 최단거리 및 최소시간에 따라 예상되는 탄소배출량 및 운반단가를 구할 수 있었다. 이 결과를 바탕으로 사토장을 선정할 경우 소나무 한그루를 심는 것과 비슷한 효과의 탄소배출량을 감소할 수 있을 것이다. 또한, 건설 분야 전반에서 발생하는 탄소배출에 영향을 주는 복합적인 요소들을 고려하여 적용한다면 탄소배출량을 획기적으로 줄일 수 있을 것이다.

• KEPCO Journal on Electric Power and Energy
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• 제6권2호
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• pp.157-161
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• 2020

온실 가스 감축과 관련하여 BIPV (Building Integrated Photovoltaics)는 청정 에너지 자원을 바탕으로 도심의 빌딩에서 자체적으로 전력을 생산할 수 있는 중요한 기술이다. 특히, 페로브스카이트 물질은 투명성을 지니고 있으며, 다양한 색상 구현이 가능하여 BIPV용 태양전지로 주목받고 있다. 그러나 태양전지의 투과도와 효율은 서로 반비례 관계에 있어 두 인자를 모두 높이는 것은 쉽지 않은 과제이다. 따라서 본 논문에서는 투과도와 효율을 모두 높일 수 있는 반투명 페로브스카이트 태양전지 구조를 제안하고, 이를 평가하였으며, 안정성 평가를 위해 국제표준에 따른 내구성 평가를 수행하였다.

• 한국농림기상학회지
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• 제1권1호
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• pp.52-59
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• 1999

Vegetation canopy plays an important role in $CO_2$/$H_2$O exchange between the biosphere and the atmosphere by controlling leaf stomata. In this study, rice (Oryza sativa L.), a staple crop in Asia was investigated to formulate its single leaf model of photosynthesis and stomatal conductance. Photosynthesis and stomatal conductance were measured with a portable infrared gas analyzer system. Other plant and meteorological variables were also measured. To evaluate empirical constants in this biochemical leaf model, nonlinear least squares technique was used. The maximum catalytic activity of enzyme and the maximum rate of electron transport were $ 100\mu$㏖ $m^{-2}$ $s^{-1}$ and $140 \mu$㏖ m$^{-2}$ s$^{-1}$ (@ 35$^{\circ}C$), respectively. The empirical constants, m and b, associated with stomatal conductance model were 9.7 and $0.06 m^{-2}$ $s^{-1}$ , respectively. On a leaf scale, agreements between the modeled and the measured values of photosynthesis and stomatal conductance were on average within 20%, and the simulation of diurnal variation was also satisfactory On a canopy scale, the Simple Biosphere model(SiB2) was tested using the derived parameters. The modeled energy fluxes were compared against the micrometeorologically measured fluxes over a rice canopy. Agreements between the modeled and the measured values of net radiation, sensible heat and latent heat fluxes, and $CO_2$ flux (i.e., net canopy photosynthesis) were on average within 25%.

• 콘크리트학회논문집
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• 제13권3호
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• pp.277-284
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• 2001

경화콘크리트는 골재와 시멘트 수화물에 의한 매트릭스 구조로 되어진 다공체이기 때문에 내부에 다양한 크기와 형태의 공극을 갖으며, 공기투과성을 갖게 된다. 이러한 투기성능은 탄산가스의 침투.확산에 따른 중성화속도와 산소와 물의 침투에 따른 철근의 부식속도를 결정하게 되어 철근콘크리트 구조물의 내구성과 밀접한 관련이 있는 것으로 보고되고 있다. 한편, 중성화속도 및 투기성능은 표면 마감재 및 콘크리트의 함수율에 의해 크게 영향을 받게 된다. 이에 본 연구는 물-시멘트비 및 마감재의 종류, 양생조건이 콘크리트의 중성화속도 및 투기성에 미치는 영향을 검토하고, 양생조건에 따른 함수상태가 투기성에 미치는 영향을 검토하였다. 본 실험결과 중성화속도 및 투기성은 물-시멘트비, 마감재의 유무 및 종류, 양생조건에 의해 크게 영향을 받으며, 콘크리트의 투기계수는 중성화속도계수와 밀접한 관련이 있는 것으로 나타나, 향후 중성화속도를 평가함에 있어서 투기계수를 요인으로 추정 가능할 것으로 사료된다.