PURPOSES : The objective of this study is to investigate the capability of the combined model of traffic simulation, emission and air dispersion models on the impact analysis of air quality of mobile sources such as vehicles. METHODS : The improvement of the quality of life brings about the increasing interest of the public environment. Many endeavors including the travel demand management, the application of the state-of-the-art ITS technologies, the promotion of eco-friendly vehicles have been tried in transportation area to reduce the modal emissions. Especially, it is expected that the increasing number of eco-friendly vehicles in the road network would be able to reduce the pipe-tail emissions tremendously. From this perspective, we have performed a study on the impact analysis of the popularization of the eco-friendly vehicle in the place of the fossil fuel energy powered vehicles on the surrounding air quality using the combined framework of microscopic traffic simulation, emission and air dispersion model. RESULTS : The combined model successfully captured the effect of moving to the eco-friendly vehicles on the air quality, and the results showed that the increasing usage of eco-friendly vehicles can improve the surrounding air quality tremendously and that the air dispersion model plays a crucial role in the investigation of the air quality change around the main corridor. CONCLUSIONS : This study demonstrated the capability of the combined model showing the spatio-tempral change of emission concentration.

This paper investigates the downwash effect of a rooftop structure (RTS) representing a typical RTS with jet diffusion. The effect of rooftop structure height on the severity of the downwash effect is assessed. As a result, design guidance provided for determining structure height required to avoid the downwash effect.

A novel route to prepare Nd-Fe-B magnetic particles by utilizing both spray drying and reduction/diffu- sion processes was investigated in this study. Precursors were prepared by spray drying method using the aqueous solu- tions containing Nd salt, Fe salt and boric acid with stoichiometric ratios. Precursor particles could be obtained with various sizes from 2 to 10 µm by controlling concentrations of the solutions and the average size of 2 µm of precursors were selected for further steps. After heat treatment of precursors in air, Nd and Fe oxides were formed through desalt- ing procedure, followed by reduction processes in Hydrogen (H2) atmosphere and with Calcium (Ca) granules in Argon (Ar) successively. Moreover, diffusion between Nd and Fe occurred during Ca reduction and Nd2Fe14B particles were formed. With Ca amount added to particles after H2 reduction, intrinsic coercivity was changed from 1 to 10 kOe. In order to remove and leach CaO and residual Ca, de-ionized water and dilute acid were used. Acidic solutions were more effective to eliminate impurities, but Fe and Nd were dissolved out from the particles. Finally, Nd2Fe14B magnetic particles were synthesized after washing in de-ionized water with a mean size of 2 µm and their maximum energy prod- uct showed 9.23 MGOe.

Poor oral hygiene can cause severe periodontal disease. Therefore, it is necessary to educate individuals regarding the importance of maintaining good oral hygiene. To this end, in this study, we evaluated the efficacy of using a phase contrast microscope as an instructional tool for oral hygiene. Forty patients, randomly divided into test and control groups, were recruited 6 months after receiving oral prophylaxis. A phase control microscope was used as a demonstration tool for the test group, and a dentiform model was used to demonstrate the ideal tooth-brushing method for the control group. In the test group, awareness regarding the importance of proper oral hygiene was found to increase by 30%, and in the control group, awareness was increased by 20%. The overall satisfaction with the instructional program was 80% in the test and 70% in the control group. The level of understanding was 99% in the test and 80% in the control group. Instructions were easily followed by 80% of the test and 60% of the control group. Understanding of the program was significantly higher in the test group than in the control group (p < 0.05). The overall satisfaction and understanding of proper oral hygiene was over 70% for both the groups. The phase contrast microscope-based instructional program yielded higher actual practice rates. The phase contrast microscope is desirable tool for motivating patients and spreading awareness regarding the importance of maintaining good oral hygiene.

Even though offensive odor control law was enforced in 2005, the civil appeal of odor doesn’t decrease all parts of the country. On Effluent Quality Standard site, the reason why the civil appeal is filed could be the restriction which is regulated by odor concentration(dilution threshold) without considering odor emission. When regulating odor concentration only, the different scenarios were considered and analyzed for diffuse form through odor concentration, stack height and flow rate using AERSCREEN. Oder compounds from the analyzed scenarios were fluctuated by not only odor concentration but flow rate. Therefore, flow rate regulation introduction is necessary because odor concentration regulation of Effluent Quality Standard doesn’t make the civil appeal reduce. Now, Odor Effluent Quality Standard is managed by Effluent Quality Standard like air pollutants in Korea. It means, the concept conversion of Receptor-centric is need for preventing civil appeal and complaint of odor. For the odor management of receptor-centric, workplace emission is regulated in accordance with odor concentration at receptor. but it’s hard to regulate all of workplace respectively because all workplace condition is different each other In Japan, odor diffusion modeling for calculating the causal relationship between receptor and emission is used for the method to figure out the problem. By expanding odor automatic monitoring network that some of local governments have, odor emission management and continues receptor current status analysis are needed to combine and operate for resolving odor problem.

Clay dispersion has been applied in Korean coasts since 1996 to minimize fisheries impact by Cochlodinium polykrikoides blooms. Understanding of spreading and sedimentation pattern of yellow clay in the sea after dispersion would be helpful for the counter measure of possible impact on marine environment and ecosystem by the clay. Tidal current movement and sedimentation of clay targeted on Obido island, Tongyong, Korea where clay had been frequently introduced to control red tide was calculated based on numerical model. The tidal current in the Obido channel showed northwestward flow during flood tide and southeastward flow during ebb tide with the highest water velocity of 15 cm/s, particularly, in the west mouth of the channel. Overall, the velocity of residual current in Obido channel with the highest value of 10 cm/s was higher than that between Obido and Mireukdo showing 1~3 cm/s of velocity with westward flow. Spreading and sedimentation of clay by the application of numerical model in the Obido channel was calculated under the assumption that 360 tons of clay had been introduced every day for 20 days in the area during red tide period in 2003. Clay particle spreaded toward westward in the channel and subsequently northward in the outside of the channel from the release point located in the center of the channel. It was calculated that 1.5 km2 in total nearby Obido area could be affected by the clay water with more than 1 mg/L of clay concentration within five tidal cycle after dispersion. The majority of the clay particle could be settled within 100 m from the release point with the sedimentation height of 10 mm. Also, it was calculated that the clay could show 0.2 mm of sedimentation height in the west and east mouth of Obido channel.

일반적으로 액체가스운반선은 인화성 화물이나 독성물질을 운반한다. 이러한 화물들은 폭발, 화재 및 인명손상을 가져올 수 있기 때문에, 액체가스운반선의 거주구역, 서비스 구역 및 통제실은 가스의 유입이 원천적으로 차단되도록 설계한다. 이러한 이유로, IMO IGC 코드의 멤브레인형 LNG선박의 화물탱크에 설치되는 벤트 출구의 높이는 노출갑판상 B/3 또는 6m 중 큰 것 이상으로 하고 작업구역 및 전후부 통행로, 갑판상의 저장탱크 및 화물설계 액위보다 6m 이상 높게 설치하여야 한다라고 규정하고 있다. 또한 LNG 시장이 점진적으로 증가하면서, LNG선박의 크기도 증가해 왔다. 때문에 현 규정에 의하면 LNG선박의 벤트의 높이는 선박 폭(B)에 비례하기 때문에 상당히 높아져야 할 것이며, 이는 높은 벤트 마스트(Mast)로 인하여 작업의 어려움 및 전방 시야를 방해하는 등 항해의 어려움을 초래한다. 본 연구에서는 멤브레인형 LNG선의 Sea-trial시에 측정하였던 데이터 및 CFD유동해석을 통해 LNG선박 화물탱크의 벤트 출구의 높이에 대한 적합성 평가를 수행한다.

구제역 바이러스는 소나 돼지 등의 우제류 가축에 경구 또는 흡입 노출 등의 다양한 노출 경로를 통해 심각한 감염성을 유발하는 생물학적 유해인자로 국내 축산업 운영에 있어 막대한 경제적 손실을 초래하는 병원균들 중 하나다. 구제역 발병에 대한 사전적 예방 관리를 도모할 수 있는 조치 방안 중 하나는 공기를 통해 전파되는 구제역 바이러스 확산에 대해 수학적 모델 적용을 통해 예측된 분석 결과에 따라 설정될 수 있다. 대기 확산 모델들은 일반적으로 구제역 바이러스의 주요 전파 경로인 경구 및 접촉 감염의 노출 시나리오를 예측할 수는 없으나, 상대적으로 예측도가 높은 대기 확산 모델의 경우 공기 전파에 대한 구제역 바이러스의 위해성 관리 방안을 결정하는 데 주요 역할을 담당할 수 있는 유용가능한 수단으로 여러 나라에서 활용되어 왔다. 구제역 바이러스 전파를 억제하기 위한 엄격한 관리 방안 중 다량의 가축 살처분 방법은 축산 농가들에게 심각한 경제적 손실을 초래하여 심각한 경우 새로운 자립의 여건마저도 상실시킬 수도 있다. 반면 낮은 수준의 대응 방안은 향후 구제역 발생에 따른 추가적 피해를 근원적으로 억제할 수 없는 역학적 한계에 봉착할 수 있다. 본 연구는 구제역 바이러스의 기본 특성 및 발생 모델 적용에 따른 공기 중 전파의 감염 위험성 평가 관련 선행 문헌들을 고찰하였다. 또한 1970년대 이후 구제역 바이러스의 공기 전파 경로를 예측하기 위해 여러 나라에서 실제 활용된 다양한 대기 확산 모델들의 적용 사례 및 장/단점을 비교 분석하였다.

미국선녀벌레[Metcalfa pruinosa (Say, 1830)]는 2009년 서울, 경기(수원), 경남 (김해)에서 처음으로 발견된 선녀벌레과(Flatidae) 외래해충이다. 이 해충은 원산 지인 북미지역에서는 피해가 미미하였으나 1979년 이탈리아를 시작으로 2000년 대 중반까지 유럽지역에서 꾸준히 분포가 확대되면서 농작물 및 산림해충으로서 널리 알려지게 되었다. 과수, 채소 등 농작물 피해는 약충과 성충의 흡즙과 분비물 (밀납)에 의한 직접적인 피해 이외에도 잎, 줄기에 서식하는 약충 집단의 감로 분비 에 따른 그을음에 의한 피해가 매우 위협적이다. 우리나라에서 미국선녀벌레에 의 한 농작물 피해는 아직 초기단계로서 이 해충의 주요한 증식처인 산림 인근에 위치 하는 사과, 배, 감 등 과수원에서 부분적으로 관찰되고 있다. 이 해충의 분포확산은 알이나 약, 성충이 부착된 식물의 인위적인 이동, 약충의 도약 또는 성충의 비행을 통한 자연확산, 그리고 성충이 차량에 부착하여 원거리 이동에 의한 것으로 추정되 고 있다. 지난 2년간(2010-2012) 중부지역을 중심으로 미국선녀벌레의 분포확산 을 추적한 결과, 2010년도에는 인천(남구), 경기(과천, 안성, 용인, 이천, 파주), 충 북(단양, 음성, 진천, 청원, 충주), 충남(공주, 태안)에서, 2011년도에는 인천(중구), 충북(괴산), 충남(금산, 예산), 전북(익산)에서, 그리고 2012년도에는 경기(여주), 강원(원주), 충남(천안), 부산(해운대)에서 추가 발생하여 누적 분포지역은 2012년 현재 6개도 31개시군이었다. 주요한 확산경로로 추정되는 고속도로 휴게소 및 진 출로의 발생지점과 주요한 기주식물을 제시하고자 한다.

In the present study, we systematically investigated the effect of Mn addition on nitrogenation behavior and magnetic properties of Sm-Fe powders produced by reduction-diffusion process. Alloy powders with only single phase were successfully produced by the reduction-diffusion process. The coercivity of powder rapidly increased during nitrogenation and reached the maximum of 637 Oe after 16 hours. After further nitrogenation, it decreased. In contrast, the coercivity of powder gradually increased during nitrogenation for 24 hours. The coercivity of powder was higher than that of powder at the same condition of nitrogenation. It was considered that the Mn addition facilitates the nitrogenation of powder and enhances the coercivity.

In this paper, a three dimensional numerical analysis tool was applied to study the PEMFC performance characteristics. The porosity and electrical conductivity of GDL and CL as well as the relative humidity of anode and cathode channel gas were selected as simulation parameters. As the porosity of GDL and CL increases, current density and temperature increase because reactant gases diffuse well. As the electrical conductivity of GDL and CL increases, current density and temperature increase due to increased electron transfer rate. As anode relative humidity increases, current density and temperature increase. Unlike anode, current density and temperature increase when cathode relative humidity increases from 0 percent to 60 percent. Then current density and temperature decrease when cathode relative humidity increases from 60 percent to 100 percent.

During the laser-assited endoscopic surgery, the laser light is delivered to the deep tissue or the internal organ using a light transmitting delivery system. It is necessary to modify the direction of the light emission at the distal end of fiber tip for some application of in laser-assisted surgery. The homemade diffusing fiber and the forward firing fiber are used for the endoscopic delivery system of the continuous IR laser into the water rich tissue. The beam emission and the laser-assisted ablation and coagulation pattern were compared for two distinctive fiber systems. The diffusing fiber produced cavity and coagulation zone more or less a circular shape, while the forward fiber produced an elongated cavity and coagulation region. The diffusing fiber produced wider and shorter coagulation and cavity zone compared to that of forward-firing fiber

담배가루이(Bemisia tabaci)는 유전적 형질이 다르지만 형태적 구별이 어려운 다양한 biotype의 집합체로서 species complex 형태로 존재한다. 최소한 20여개의 biotype이 알려져 있으며 각 biotype은 발생율, 기주식물의 선호도, 환경적응성, 및 특정 살충제 저항성 등 다양한 생리적 및 생태적 차이를 나타낸다. 이 중에서 B biotype과 Q biotype이 전세계적으로 확산되어 분포하며 특히 최근에 확산된 Q biotype은 imidacloprid 계통의 살충제에 저항성이 높은 것으로 보고되었다. 또한 담배가루이는 100여종 이상의 식물바이러스를 매개하는 매개충으로서 다양한 작물에 간접적인 피해를 끼친다. 바이러스 매개작용과 관련하여 담배가루이의 내부공생균(endosymbiont)이 매개작용에 중요한 역할을 한다. 특히, 최근 국내뿐만 아니라 전세계적으로 심각한 피해를 끼친 토마토황화잎말림병 바이러스(TYLCV)는 담배가루이 체내의 Hamiltonella 내부공생균이 존재함으로서 매개될 수 있다. Q biotype 중에서지중해지역에 분포하는 Q2 biotype은 이 공생균이 존재하지 않아서 TYLCV를 매개하지 못하지만 2008년 국내에 침입한 Q1 biotpype은 이 공생균이 존재하며 TYLCV를 매개하여 전국에 확산시킨 바 있다. 즉, 담배가루이와 같이 복잡한 형질을 가진 종들은 종수준이하의 subgroup 수준에서 확산 및 위해성 정도가 다르게 나타날 수 있다. 그르므로, 외래침입해충의 위해성 분석 측면에서 종내의 subgroup에 대한 유전적 형질의 분석이 필요하며 특히 식물 질병 매개충의 경우에는 매개충의 바이러스 보독 여부 및 각 subgroup의 내부공생균과 같은 특징에 대한 분석 및 진단체계가 확립되어야 한다고 판단된다.

Kang Hui-suk. 2012. A Sociolinguistic Analysis of Fetus Naming and Its Diffusion. The Sociolinguistic Journal of Korea 20(2). pp. 33-61 . This study attempted a socilinguistic analysis on the fetus naming and its diffusion as a new custom. The subjects of the study were 248 first-graders of elementary schools, 175 young children from nurseries and 423 parents who are living in Gwangju and Damyang in Jeonnam. The results are summarized as follows: First of all, the types of fetus naming and naming principles were analysed and it was discovered that most of fetus names were Korean, not Chinese, such as bokdeongi, teunteuni or ttolttori while real names were usually Chinese. Real names were made by parents or name experts in consideration of Saju or meanings of names after babies were born. However, fetus names were given by their parents in the early or middle periods of pregnancy. As a result of examining how many children had fetus names in each class, it was discovered that 43.5% of the first graders had fetus names and 76.9% of young children in nurseries had them. It shows that the custom of fetus naming is expanding very fast and such expansion was found both in urban and rural areas. When motives to give fetus names were analysed, it was discovered that parents intended to talk to their babies calling their names every day, thinking the fetus are lives with personality. They believed that when names are called frequently, the meanings of the names can be achieved. 66.5% responded that fetus names are necessary. Also, parents felt babies exist through fetus names. The names weremeans of conversation and worked to enhance friendliness and rapport between parents and their babies. The names gave helps to prenatal care as well as delivered what parents expect to the babies, enhanced rapport between parents and babies, removed anxiety of pregnancy and added happiness to their life.