L.P SCR의 촉매 반응을 위해 선박의 발전기용 4행정 디젤엔진의 배기가스 온도를 높게 설계 할 수밖에 없었다. 본 연구의 목적은 밸브개폐시기와 연료분사시기를 조정을 통한 배기가스의 온도 감소가 L.P SCR의 운전조건을 만족시키고 고온으로 인한 발전기 엔진의 사고를 예방하기 위함이었다. 배기가스 온도를 하강시키기 위해 캠샤프트의 각도를 조정하고 연료분사펌프의 Shim을 추가하였다. 그 결과 최대폭발압력은 12.8 bar 증가하였고 터보차저 출구온도 평균값은 13.3 ℃ 하강하였다. 터보차저 출구에서 SCR 입구까지의 열손실을 감안하더라도 L.P SCR 운전조건인 SCR 챔버 입구 온도인 290 ℃를 만족하였다. 배기가스 온도 하강을 통해 디젤발전기의 안전운전이 가능하게 한 연구였다.

Upo Wetland is the largest riverine wetland in Korea which has been inscribed on the Ramsar List of Wetlands of International Importance in 1998. In this study, sedimentological study was carried out in order to understand the environmental changes in Upo Wetland during the Holocene. The drilling work for recovering the Quaternary sediments was conducted on the inner part (UPW17-01, UPW17-02, and UPW17-03) and the outer part (UPL17-01, UPL17-02) of the Upo Wetland. The recovered sediments are commonly characterized by gravel-dominated deposits in the lower part and silty clay-dominated deposits in the middle to upper parts respectively, which are seemed to be changed from fluvial to palustrine/lacustrine environments around 4,000 cal yr BP. In order to establish the Holocene diatoms distribution from Upo Wetland, we identified 63 diatom taxa. Of these, 14 species were new records for Korea: Gomphonema consector, Gomphonema jadwigiae, Hantzschia abundans, Luticola pseudomurrayi, Luticola spauldingiae, Neidium suboblongum, Ninastrelnikovia gibbosa, Oricymba rhynchocephala, Pinnularia borealis var. lanceolata, Pinnularia latarea, Pinnularia paliobducta, Pinnularia saprophila, Sellaphora laevissima, Stauroneis pseudoschimanskii. All identified diatom species are illustrated by high-quality scanning electron microscopic and light microscopic microphotographs. The ecological habitat for all taxa are presented.

본 연구에서는 국제해사기구(IMO)의 뜨거운 관심분야로 부상되고 있는 선박기인 입자상물질(PM)과 오염물질 배출에 관하여 한국해양대학교 실습선 한바다호를 이용하여 계측하였다. 특히, PM은 TEM 그리드를 이용해 채취하고 전자현미경으로 구조를 파악하였으며, NOx, CO₂, CO 등의 배기가스는 연소가스분석기(PG-250A, HORIBA)를 이용해 측정하였다. 본 연구의 결과는 다음과 같다. 1) 선박이 항구에서 출항할 때, Bunker Change로 인한 PM 배출량은 최대 30 % 정도 차이가 있었다. 2) 정속 운항을 하면서 Bunker-A에서 L.R.F.O(3 %)로 변경할 때 측정한 PM 배출량은 1.34㎎/㎥, L.R.F.O(3 %)로 고정해 측정한 PM 배출량은 1.19㎎/㎥, L.R.F.O(3 %)만 사용하며 주기관 회전수를 20 % 증가시키면서 계측한 PM 배출량은 1.40㎎/㎥이었다. 또한, 저질유(L.R.F.O(3 %))로 변경시 CO 농도는 약 16 % 증가하는데 비해 RPM을 20 % 상승시킨 경우에는 152 % 이상 급격한 증가를 보였다. 이러한 결과로부터 배기가스 배출의 증가는 연료유종의 영향도 있으나, RPM의 변화에 민감하다는 것을 알 수 있었다. 3) TEM 그리드로 채취한 PM은 약 4~10㎛ 정도의 다양한 입경을 가지는 다공질 응집체 형상의 구조인 것으로 확인하였다.

본 연구에서는 한국해양대학교 실습선 한바다를 이용하여 선박의 입․출항 및 약 150 rpm의 정속 운항 할 때 주기관에서 배출되는 배기가스를 실시간 계측하였다. 실측 결과 질소산화물의 농도는 정속 운항시 800 ppm 에서 1,000 ppm 사이인데 반해, 입․출항시에는 210 ppm 에서 1,230 ppm 까지 큰 범위에서 값이 변화하였다. 일산화탄소의 농도 역시 정속운항 상태 보다 입․출항시 측정값의 변화가 크게 나타났다. 이러한 결과는 입․출항시 가능한 한 주기관의 부하변동이 급격히 발생되지 않도록 하는 선박 조종 스킬이 필요하다는 것을 의미한다. 또한, 배기가스 저감 기술의 적용에 있어 입․출항시와 정속 운항할 때 그 차이를 고려할 필요가 있다는 것을 나타낸다.

This research was done to clarify the cooling effect of water particles generated from a fountain. This effect is a one way to control the heat island effect of big cities. The result of this research was drawn by setting the jets of water in a certain height, and then studying the diffusion of water particles, which is affected by the size of the particles and the wind speed, and the cooling effect caused by the diffusion. 1) When a diameter of a water drop was 500 ㎛ and the wind speed was 2.0 to 6.0 m/sec, the water drop diffused 75 to 190m, and the water vapor spread over 175 to 440 m. As a result, there was more than 0.5℃ of cooling effect on the temperature in the atmosphere 130 to 330m around the water fountain. 2) When a diameter of a water drop was 750 ㎛ and the wind speed was 2.0 to 6.0 m/sec, the water drop diffused 65 to 150 m, and the water vapor spread over 160 to 405 m. Moreover, there was more than 0.5℃ of cooling effect on the temperature in the atmosphere 110 to 275 m around the water fountain. 3) After studying on the relationship between the diameter of water drop and the wind speed, and the diffusion of water particles and the range of the atmosphere that was cooled, a result could be drawn from the research that the smaller the diameter of the water vapor gets and the faster the wind speed becomes, the wider the water particles diffuse and the cooler the atmosphere around the fountain becomes. 4) This research further extrapolates that when the ordinary water(tap water, water from river and stream) is used in a fountain, the cooling effect of the air near the fountain can be approached similarly. If the seawater is used in a fountain, there is to be more to concern not only on cooling effect on the air, but also on other effects on surrounding environment generated by the salt in seawater.

The present study applied an atmospheric flow field model in Gwangyang-Bay which can predict local sea/land breezes formed in a complex terrain for the development of a model that can predict short term concentration of air pollution. Estimated values from the conduct of the atmospheric flow field were used to evaluate and compare with observation data of the meteorological stations in Yeosu and the Yeosu airport, and the effect of micrometeorology of surround region by the coastal area reclamation was predicted by using the estimated values. Simulation results, a nighttime is appeared plainly land breezes of the Gwangyang-bay direction according to a mountain wind that formed in the Mt. of Baekwooun, Mt. of Youngchui. Land winds is formed clockwise circulation in the north, clockwise reverse direction in the south with Gangyang-bay as the center. Compared with model and observation value, Temperature is tend to appeared some highly simulation value in the night, observation value in the daytime in two sites all, but it is well accorded generally, the pattern of one period can know very the similarity. And also, wind speed and wind direction is some appeared the error of observation value and calculation results in crossing time of the land wind and sea land, it can see that reproducibility is generally good, is very appeared the change land wind in the nighttime, the change of sea wind in the daytime. And also, according to change of the utilization coefficient of soil before and after development with Gwangyang-Bay area as the center, Temperature after development was high 0.55～0.67℃ in the 14 hours, also was tend to appear lowly 0.10～0.22℃ in the 02 hours, the change of u, v component is comparatively tend to reduced sea wind and land wind, it is affected ascending air current and frictional power of the earth surface according to inequality heating of the generation of earth surface.

In this study, characteristics of fog at Mokpo as the west coastal area of Jeonnam were investigated, using statistical analysis of observed fog and meteorological data. Higher frequency of the fog occurrence at Mokpo was showed in spring(32%) and summer(34%) due to the seasonal high atmospheric pressure. Regional characteristics as radiation cooling, advection of fog and water vapor from surrounding sea and Yeongsan lake, and frontal fog had major effect on the coastal fog at Mokpo on the meteorological conditions of north-west/south wind and calm(0～2m/s). Also, as the results of analyzing data of before and after the construction of Yeongsan dam, the frequency of annual mean fog days increased 41%, specially increased 178% in autumn. The increase of fog days mainly resulted from evaporation during colder seasons and from temperature inversion during warmer seasons over the water surface of Yeongsan lake. The construction of Yeongsan dam had a little effect on the meteorological conditions concerning fog occurrence, because Yeongsan dam which only supplies the water for use do not always carry out outlet of the cold water. In addition, the sea fog at Heuksando located in offshore had not effect on the occurrence of fog at Mokpo.

A three-dimensional photochemical air pollution model considered advection, dispersion, photochemical reactions, and precipitation processes was developed. The calculated results of meteorological observation clearly exhibited geographical effects of Gwangyang Bay, in which land and sea breezes, mount-valley winds and local circular winds occurred. The observed results of daytime NOx concentrations were slightly higher than the calculated NOx concentrations in Yosu industrial complex, Gwangyang iron mill, and container yard. Eventually, the calculated NOx results generally agreed well with the observed ones.

In genneral, Businger expression is used for determining a turbulance diffusion coefficient. In this study, it is applied to the surface elements of cities such as Asphalt, Ground, Grass, Pond. We set up 5 m-height bar and measured the dry temperature and wet temperature at the height of 0.13, 0.27, 0.5, 1.0, 3.0, 5.0 m. In addition we measured the wind gradient and wind velocity at the height 3 m, solar radiation continuously for 48 hours on the surface. Compared the measured data to Businger expression, the result showed that Businger expression can be well applied to the complex surface of the city.