Odor compounds and air-born microorganisms are simultaneously emitted from various aeration processes such as aerobic digestion, food-waste compositing, and carcass decomposition facilities that are biologically-treating wastes with high organic contents. The air streams emitted from these processes commonly contain sulfur-containing odorous compounds such as hydrogen sulfide(H2S) and bacterial bioaerosols. In this study, a wet-plasma method was applied to remove these air-born pollutants and to minimize safety issues. In addition, the effects of a gas retention time and a liquid-gas ratio were evaluated on removal efficiencies in the wet-plasma system. At the gas reaction time of 1.8 seconds and the liquid-gas ratio of 0.05 mLaq/Lg, the removal efficiency of bioaerosol was approximately 75 %, while the removal efficiency of H2S was lower than 20 %, indicating that the gaseous compound was not effectively oxidized by the plasma reaction at the low liquid addition. When the liquid-gas ratio was increased to 0.25 mLaq/Lg, the removal efficiencies of both H2S and bioaerosol increased to greater than 99 %. At the higher liquid-gas ratio, more ozone was generated by the wet-plasma reaction. The ozone generation was significantly affected by the input electrical energy, and it needed to be removed before discharged from the process.

연안에서 발생하는 부유물질에 의한 해양생물영향을 평가하기 위한 기초자료를 제공하기 위하여, 유용 해양생물(패류, 어류, 해조류 등)에 대한 부유물질의 영향에 관한 문헌을 수집하고 분석하였다. 1) 부유물질에 의한 해양생물들의 영향에 관한 논문은 주로 패류에 대해서 이루어져 있다. 2) 해양생물에 대한 부유물질의 영향은 주로 급성독성에 대해서 조사가 이루어져 있다. 3)부유물질에 의한 영향 실험은 성패와 치패기의 패류, 난 및 치어기의 어류에 집중되어 있으며, 해조류는 포자를 이용한 연구가 주로 이루어졌다. 부유물질에 의한 생물학적 영향은 부유물질의 농도, 노출기간, 생물의 성장단계에 따라 다양하게 나타날 것이며, 이에 대한 검토는 부유물질의 영향에 대한 이해를 향상시킬 것이다.

This study investigated the emission characteristics of airborne particles and bacteria from six types of household vacuum cleaners in the closed chamber. A test cleaner without HEPA filter was examined focusing on the first one minute of initial operation, observing significant generation of airborne particles, and especially for particle size of 0.5 to 2.5 μm, the generation rate increased up to 68.5 × 103 particles/min. Concentrations of airborne particles and bacteria depends on the production year, the motor power, and the dust filter efficiency of the vacuum cleaner. The observed results should be taken into consideration in the design of the vacuum cleaner as well as how they are operated in indoor environment.

Considering a rigorously fluid-structure interaction, a method for an earthquake response analysis of a floating offshore structure subjected to vertical ground motion from a seaquake is developed. Mass, damping, stiffness, and hydrostatic stiffness matrices of the floating offshore structure are obtained from a finite-element model. The sea water is assumed to be a compressible, nonviscous, ideal fluid. Hydrodynamic pressure, which is applied to the structure, from the sea water is assessed using its finite elements and transmitting boundary. Considering the fluid-structure interaction, added mass and force from the hydrodynamic pressure is obtained, which will be combined with the numerical model for the structure. Hydrodynamic pressure in a free field subjected to vertical ground motion and due to harmonic vibration of a floating massless rigid circular plate are calculated and compared with analytical solutions for verification. Using the developed method, the earthquake responses of a floating offshore structure subjected to a vertical ground motion from the seaquake is obtained. It is concluded that the earthquake responses of a floating offshore structure to vertical ground motion is severely influenced by the compressibility of sea water.

본 연구에서는 부유토사로 인한 탁도 증가가 어류에게 미치는 영향에 대해 실험실 모의실험을 수행하였다. 국내 강 또는 호소에서 출현 비율이 높은 붕어, 잉어, 송사리를 대상으로 수정란 부화율 평가를 수행한 결과 붕어, 잉어는 4,040 NTU 수준까지 수정란 부화에 미치는 영향이 없었지만, 송사리는 254 NTU 이상의 구간에서 부화율이 저해되는 영향을 보였다. 붕어, 잉어, 송사리 치어의 4일간 노출 결과 생존에 미치는 영향은 없었다. 반면 성장률 결과에서 잉어와 붕어는 7일, 14일, 21일 모두 143 NTU 구간부터 성장저해 영향을 보였다. 송사리는 14일 노출 시 254 NTU, 21일간 노출 시 501 NTU 구간부터 성장저해 영향을 보였다. 따라서 강 또는 호소에서 143 NTU 이상의 탁도가 발생할 경우 붕어, 잉어의 성장을 저해시킬 수 있고, 250 NTU 이상의 탁도는 송사리와 같이 민감 어종의 부화율이 저해될 수 있을 것으로 사료된다.

본 연구에서는 금강 하구역의 부유사 변동과 퇴적물의 상호연관성을 정량적으로 평가하고 그 기작을 규명하기 위하여 현장조사 및 수치실험을 수행하고 최종적으로 금강하구의 퇴적물 분포 및 이동 패턴 특성을 제시하고자 하였다. 1) 대조기 평균 부유사농도는 PC4를 제외한 모든 정점에서 하구둑 방류에 의한 영향이 미치는 것으로 보인다. 동계에는 PC3과 PC5에서 다른 정점에 비해 높게 나타나며, 이는 파랑과 방류량에 의해 발생된 부유사가 장항항 진입항로에서..

The floating PV generation structure installed on the surface of water has been recently issued as a representative items for the low carbon and green growth campaign. Moreover, the studies and developments for the structure and construction improvements of floating PV generation structure have been in progress. For example, in the previous research, the floating PV generation structure consisted of pultruded FRP and SMC FRP members is suggested. In this study, we conduct the analytical and experimental studies for estimating the structural characteristics of SMC FRP vertical members. From the analytical and experimental results, it is found that SMC FRP vertical members used for floating PV generation structure have sufficient structural safety and stability.

The current interest in atmospheric particulate matter (PM) is mainly due to its effect on human health.Exposure to outdoor PM is associated with a wide range of adverse health effects. Indoor air contains a complexmixture of bioaerosols such as bacteria, fungi and allergens. Children are known to be more susceptible tothe exposures of PM and bioaerosols which are represented by airborne bacteria, fungi, and allergens. Thisstudy is to assess concentrations of the atmospheric PM and bioaerosols indoors and outdoors at 15 daycarecenters for children located in Seoul. Particles were measured indoors and outdoors with automatic particlemonitoring using beta radiation absorption. Airborne bacteria and fungi were sampled by Anderson sampler.Analysis shows that average indoor PM10 was 95.7µg/m³ (SD 26.6µg/m³) and average level of airbornebacteria and fungi were 575.0CFU/m³ (SD 431.6CFU/m³) and 77.9CFU/m³ (SD 45.6CFU/m³), respectively.Finally, efficient ventilation and effective air cleaning strategies are necessary to reduce indoor concentrationsof particles and bioaerosols.

Recently SARS and bird flu has been infected widely in the world; we have to care about germs and virus in indoor air environment. Especially that transmission by means of transportation is a major infection route. In this study, a private car simulated with CFD for prediction of indoor airborne microbe transport. Simulation performed with real situation in car, four occupants with a infected driver and four stage air ventilation controled by HVAC system. Result show that CFD can be visualized microbe transport other occupants and who is more exposed to airborne microbe. also it make a prediction of microbe transport in car.

발아기를 전후한 이상기후로 감나무의 신초 생장이 늦어지는 경우가 많다. 본 연구는 봄철의 생장 지연이 ‘부유’의 신초 및 과실 생장에 미치는 영향을 파악하고자 수행되었다. 신초 생장 지연을 유도하기 위해 탈순화 과정에 있는 눈의 온도조건을 달리하였는데, 발아 전인 3월 12일부터 정상 나무의 발아3일 후인 4월 8일까지 3~4년생 측지에 폴리에틸렌 비닐주머니를 씌우는 방법으로 하였다. 비닐주머니를 설치했던 가지는 낮 온도가 2~5℃ 높아진 반면 밤 온도는 외기온과 같아 주야간 온도변화 폭이 커졌고, 그 결과 4월 동안 발아와 신초 생장 지연 정도가 달라졌다. 4월 27일에 길이 0.5~10 cm 범위의 신초를 30개 선정하여 길이를 측정하고 각각의 생장을 추적 조사하였다. 생장 지연이 심한 신초일수록 개화가 늦어 7일까지 차이가 있었고 엽장이 짧아졌으나 신장이 종료된 신초장은 차이가 없었다. 신초 생장 및 개화가 지연될수록 수확 과실의 크기가 작아진 반면, 색도, 경도, 당도는 유의적인 변화가 없었다.

Since airborne fungi have been known to aggravate indoor air quality, studies on developing anti-fungal filters increase recently. In this study, silver (Ag) nanoparticle was selected as anti-fungal agent. HEPA filter was coated with silver nanoparticles which were generated via spark discharge system operating at atmospheric pressure and temperature. The anti-fungal effect of the Ag-filter was evaluated with the conventional culture assay. When the number of Ag nano particle per a fungal particle in the filter was 1.91X106, the fungicidal efficiency was higher than 99%. As another anti-fungal test, ATP bioluminiscence detection method was also carried out and the results were correlated with those of the culture assay.

Recently, airborne fungi as indoor air pollutant have attention due to its health related problems such as asthma, rhinitis, sinusitis, atopy, pneumonia, building syndrome and etc.. However, it is considered that current laws and policies in Korea are not efficient to deal with these problems. Our research investigated influential factors and species distribution on the basis of previous research related to airborne fungi issue conduced in Korea by applying meta analysis technique. We selected 15 articles containing variables affecting fungi population such as outdoor air characteristics, temperature, location, and ventilation to evaluate significant factors. It was confirmed that airborne fungi level has partial correlation to those factors despite of limited sample size. It is required that the consistent and systematic research effort should be extended to characterize health effect caused by these fungi as well as to control them efficiently.

본 연구는 2011년 3월부터 2012년 5월까지 부영양수 계에 네 가지 여재(스펀지, 화산석, 활성탄, 수산화마그네 슘)를 사용한 부유습지를 설치하여 장기적인 수질변화를 조사하였다. 또한 부유습지에 유입되는 유입수와 네 가지 여재를 거쳐 최종적으로 통과된 유출수내의 식물플랑크 톤과 동물플랑크톤 군집을 분석하였다. 실험기간 동안 탁 도(66%), SS (79%), Chl-a (80%), COD (24%)의 농도는 유 입수에 비해 유출수에서 뚜렷하게 높은 감소율을 나타냈 다(p⁄0.001). NO2-N와 NH3-N은 각각 24%, 20%로 유 의한 감소를 나타냈으나(p⁄0.05), NO3-N와 TN은 평균 10% 미만의 제거율을 나타내었다(p¤0.05). 한편 PO4-P 와 TP는 모두 평균 65% 이상의 제거율을 나타냈다(p⁄ 0.01). 또한 식물플랑크톤밀도는 유출수에서 유입수보다 2.6배 정도 낮게 나타낸 반면, 동물플랑크톤은 유입수보 다 유출수에서 평균 3.5배 이상 높은 밀도를 나타내었다. 본 연구에서 네 가지 여재를 이용한 수질개선용 부유습 지는 특히, 입자성 물질(SS, Chl-a, COD, TP)과 용존성 영양염(NO2-N, NH3-N, PO4-P)에 대하여 높은 제거율을 나타내어, 결과적으로 부영양 호소에서 수질개선 및 조류 저감에 대한 적용가능성을 보여주었다.