• 한국입자에어로졸학회지
• /
• 제9권3호
• /
• pp.149-161
• /
• 2013

Experiments on photochemical reactions of purified air alone in an indoor smog chamber were carried out after flushing Teflon bags with purified air for many hours in order to check the level of contamination on the chamber wall. Ozone concentrations were linearly increased from <4 ppb up to about 8 ppb with irradiation time for four hours. Outgassing of NOx from the chamber wall was found to be less than 1 ppb. New ultrafine particles were formed and grown up to about 70 nm during the photochemical reactions, and then total number and mass concentrations of particles were increased from <10 particles/$cm^3$ up to about 4,000 particles/$cm^3$ and $1.3{\mu}g/m^3$, respectively. The wall conditions of these Teflon bags flushed with purified air might not severly affect the chamber experimental results for photochemical reactions of polluted urban ambient air. The difference of gaseous species between two chambers was 2.4 ppb of ozone at most, indicating that the wall cleaning performance of two chambers was nearly similar.

• 대한건축학회논문집:계획계
• /
• 제36권4호
• /
• pp.71-81
• /
• 2020

The purpose of this study is to propose the planning methods for pollution prevention in the initial design stage by identifying the pollution phenomena on the exterior of the building. It is important to catch the problem early on because exterior troubles begin with an initial design defect and causes rapid aging. The scope of this study is seoul public borough offices that should be sustainable for long as landmark located at the center of the district. Field survey was conducted three times in six months. Twenty-six borough offices were diagnosed with three levels of contamination through visual inspection and the contaminated locations, types, materials, and characteristics were checked. Fourteen common contaminated locations were identified in the first and intensively rechecked in the second. Five locations vulnerable to contamination were designated and the contamination and cleanliness situations were checked by location in the third. As a result, main polluted types and locations are sloping wall, upper wall, protruded wall, canopy, and wall under window. The key to avoiding these pollution problems is to minimize the horizontal plane on which dust can be deposited. In other words, it can be considered variously by shape and location, such as the slope of the horizontal plane, the floating of the surface, the installation of the roof surface, and the vertical louvers. And throating plans and material plans suitable for each location are presented. Various methods of the shape and location, material are expected to use as useful basic data for preventing pollutions during the initial design stage.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2003년도 추계학술발표회
• /
• pp.285-288
• /
• 2003

When the soil vapor extraction as a remediation method of contaminated soil and groundwater has been used, the effects of curtain wall, mode of pump operation were examined by numerical simulation. Consequently, it was found that the removal rate was enhanced in case that the curtain wall was established around the extraction well with the extraction pumps operated alternatively. It was because that the removal of high density gas around the extraction well was possible.

• 반도체디스플레이기술학회지
• /
• 제14권1호
• /
• pp.45-49
• /
• 2015

Process gases with vapor or liquid phase as well as gas phase may experience alteration in itself or be contaminated in the fluid pipe to the process chamber. And thus it result in as particles or defects on the substrates in semiconductor, LCD, LED manufacturing. Purifiers and filters are used for control of contamination. However, none of detection device is available in the delivery line. In this paper, we propose simple device with lighting and sensing in order to predict contamination of the fluid or the tube wall. For some general purpose gases, it showed constant voltage output regardless of the flow rates. But, the smoke and the moisture in the air lowered the figure due to its concentration. Numerical values for several solid and liquid media were obtained. And, the operating temperature tendency was investigated.

• 한국환경과학회지
• /
• 제11권11호
• /
• pp.1183-1187
• /
• 2002

Existing retaining walls are usually made from only one cast form and any damage must be promptly repaired. However, when a part of a retaining wall is repaired, a gap can be created between the repaired and existing parts, along with an unpleasing visual effect. As such, the whole structure is often reconstructed, rather than repairing one part, resulting in construction waste and possible contamination of the environment. Accordingly, the current study proposes a construction method for a retaining wall that uses separate blocks to downsize of quantity of construction waste. In addition, by changing the color or modifying the block cover a more environmentally friendly retaining wall construction method is achieved.

• 대한지하수환경학회지
• /
• 제7권1호
• /
• pp.1-7
• /
• 2000

김포매립지 내의 침출수의 누출에 의한 매립지 주변의 지하수오염을 감소시키기 위해, 매립지 내부에 5조의 수평방사형 수집정(Radial Collector Well Laterals(RCWL))을 설치하는 방법, 응축수 배제정을 이용하는 방법, 매립지의 주변에 차수벽을 2층까지 설치하고 매립지 내부에 22조의 RCWL을 설치하는 방법, 그리고 매립지 둘레에 차수벽을 3층까지 설치하고 매립지 내부에 40조의 RCWL을 설치하는 방법 등을 연구했다. 이를 위해, 수리파라미터를 측정하고, MODFLOW과 MT3D 모델을 사용하여, 김포매립지주변의 지하수 이동과 오염물질 이동체계를 분석했다. 분석결과 차수벽을 2층까지 그리고 2조의 RCWL을 설치하는 방법이 지하수 오염농도를 먹는물 수질기준까지 감소시킬 수 있는 가장 경제적인 방법으로 평가되었다.

• 한국방사성폐기물학회:학술대회논문집
• /
• 한국방사성폐기물학회 2009년도 학술논문요약집
• /
• pp.84-85
• /
• 2009

New approaches for detecting, preventing and remedying environmental damage are important for protection of the environment. Procedures must be developed and implemented to reduce the amount of waste produced in chemical processes, to detect the presence and/or concentration of contaminants and decontaminate fouled environments. Contamination can be classified into three general types: airborne, surface and structural. The most dangerous type is airborne contamination, because of the opportunity for inhalation and ingestion. The second most dangerous type is surface contamination. Surface contamination can be transferred to workers by casual contact and if disturbed can easily be made airborne. The decontamination of the surface in the nuclear facilities has been widely studied with particular emphasis on small and large surfaces. The amount of wastes being produced during decommissioning of nuclear facilities is much higher than the total wastes cumulated during operation. And, the process of decommissioning has a strong possibility of personal's exposure and emission to environment of the radioactive contaminants, requiring through monitoring and estimation of radiation and radioactivity. So, it is important to monitor the radioactive contamination level of the nuclear facilities for the determination of the decontamination method, the establishment of the decommissioning planning, and the worker's safety. But it is very difficult to measure the surface contamination of the floor and wall in the highly contaminated facilities. In this study, the poly(styrene-ethyl acrylate) [poly(St-EA)] core-shell composite polymer for measurement of the radioactive contamination was synthesized by the method of emulsion polymerization. The morphology of the poly(St-EA) composite emulsion particle was core-shell structure, with polystyrene (PS)as the core and poly(ethyl acrylate) (PEA) as the shell. Core-shell polymers of styrene (St)/ethyl acrylate (EA) pair were prepared by sequential emulsion polymerization in the presence of sodium dodecyl sulfate (SOS) as an emulsifier using ammonium persulfate (APS) as an initiator. The polymer was made by impregnating organic scintillators, 2,5-diphenyloxazole (PPO) and 1,4-bis[5-phenyl-2-oxazol]benzene (POPOP). Related tests and analysis confirmed the success in synthesis of composite polymer. The products are characterized by IT-IR spectroscopy, TGA that were used, respectively, to show the structure, the thermal stability of the prepared polymer. Two-phase particles with a core-shell structure were obtained in experiments where the estimated glass transition temperature and the morphologies of emulsion particles. Radiation pollution level the detection about under using examined the beta rays. The morphology of the poly(St-EA) composite polymer synthesized by the method of emulsion polymerization was a core-shell structure, as shown in Fig. 1. Core-shell materials consist of a core structural domain covered by a shell domain. Clearly, the entire surface of PS core was covered by PEA. The inner region was a PS core and the outer region was a PEA shell. The particle size distribution showed similar in the range 350-360 nm.

• 한국기계연구소 소보
• /
• 통권19호
• /
• pp.31-42
• /
• 1989

To investigate design factors of dilution ventilation system, numerical analysis of air contamination flow and concentration distribution have been made, by using the low Reynolds number turbulent model. And flow visualization and measurement of particle concentration for that model also have been made. By comparing of these results we have secured the essential data for the adequate counterplan of dilution ventilation system. The results of this study are as follows: 1) Inlet should be located near the wall for the prevention of the formation of the recircula¬tion zone. 2) In case of natural exhaust, air contamination flow is driven to the far outlet from the inlet. 3) It is favorable for dilution to make turbuence as much as possible.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
• /
• pp.81-85
• /
• 1998

In the present study, the design method of containment walls is proposed by utilizing an existing site. The selected remedy for the Source Area of Operable Unit 2 at Hill Air Force Base stipulated containment of the pure-phase trichloroethylene contamination. The in-place-mixed wall construction was selected because of the irregular topography, small area of the site, and the requirement to reach depths of greater than 90 feet below ground surface. Bench-scale compatibility studies were performed for the containment wall mix design on three commercial bentonite clays. The samples were subject to screening tests and long-term tests for evaluation of changed soil properties when exposed to the contaminated groundwater.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
• /
• pp.45-49
• /
• 2010

The contamination(stain phenomenon) of natural marble(sipeol, bianko) of art wall of on-site interior finishing system and wall of elevator hall has occurred. The bottom of the art wall of stone junction tile has defects as cracks. To solve these problems, our research team developed eco-friendly complex stone panel(stone 4T + cement board 6T) and high-frequency hot-melt construction method that can construct in winter.