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        검색결과 18

        1.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Low-cost particulate matter (PM) sensors based on the light scattering principle measure the concentration of particles by the change of scattering intensity after light is irradiated onto the particles. It has been reported that when the relative humidity is high, water vapor may cause the expansion of airborne particles and affect the accuracy of the light scattering method for PM measurement, but it has also been shown that the effect of humidity is not significant or even negligible. Therefore, to determine the effect of humidity on the Plantower PMS7003 light scattering sensor, in this study, a BAM1020 (Beta Attenuation Monitoring) was installed alongside to continuously monitor the ambient atmospheric PM concentration for approximately four weeks. The sensors collected data at 10-minute intervals, resulting in a 1-hour average for comparative analysis. To accurately measure humidity, the performance of the Arduino + DHT22 humidity sensor was also pre-evaluated using a series of saturated salt solutions. The humidity was grouped into five intervals and analyzed by visual analysis. The results confirmed that there was no significant correlation between PM2.5 differences and humidity, which were randomly and uniformly distributed around the mean. However, since in the very low and high concentration ranges based on the beta-ray monitor measurements, the difference between the light scattering sensor PM10 measurement and the reference value is much larger than the difference between the PM2.5 and the reference value., there is an additional need to investigate the appropriate correction method for dust season or PM10. The results show that the outcomes of the light scattering sensor are more influenced by particle size and concentration than by humidity.
        4,200원
        6.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A coal dust scattered from storage and transfer facilities of coal power plant is led to a air pollution. It is difficult to reduce some scattered coal dust by used filter system such as bag filter and electric precipitator because of being scattered in the large area. The need to cut down coal dust generation has been increased as being reinforced regulation to reduce dust from coal power plant. So this is a experimental basic study which reduces coal dust generation. This study is to reduce scattering rate of the coal dust by collision and interception between fine fog droplet and coal dust particles. The reducing rate of coal dust is evaluated by droplet size of 10㎛ sprayed. It is evaluated that capture efficiency is lower as a coal dust concentration become higher. And also it is increase as droplet size is decrase and droplet density is increase. It is resulted that coal dust coefficient to optimize the fog system design is 25μg/m3/l/hr and capture efficiency of coal dust is about 80%.
        4,000원
        7.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Conventional rotary sawing machine for cutting lumber generates severe amount of dust scattering to the environment. In this research, the design improvement of the rotary sawing machine is achieved to significantly reduce the dust scattering by the design process utilizing computational fluid dynamics (CFD) analysis. Several design candidates for the design improvement of the rotary saw system were proposed and modeled, and CFD analyses were performed to choose the best design in viewpoint of the least dust scattering. CFD analysis proved to be very useful to predict the characteristics of the air flow inside the saw system. The movement of dust particles with the air flow during the sawing process was analyzed for various design features of the saw system. The most efficient design to minimize the amount of dust particles ejected from the saw system was chosen based on the CFD analysis results. Then, the prototype of the best candidate of the improved rotary saw machine was built and the amount of dust particles were measured to verify its performance.
        4,000원
        10.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We developed an efficient Monte-Carlo algorithm to solve dust-scattering radiative transfer problems for continuum radiation. The method calculates the scattered intensities for various anisotropic factors ( gi) all at once, while actual photon packets are tracked following a scattering phase function given by a single anisotropic factor ( g0). The algorithm was tested by applying the method to a dust cloud embedding a star at the cloud center and found to provide accurate results within the statistical fluctuation that is intrinsic in Monte-Carlo simulations. It was found that adopting g0 = 0.4 - 0.5 in the algorithm is most efficient. The method would be efficient in estimating the anisotropic factor of the interstellar dust by comparing the observed data with radiative transfer models.
        4,000원
        12.
        2009.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We present a Monte-Carlo simulation code, which solves the problem of dust-scattering in interstellar dust clouds with arbitrary light source distribution and dust density structure, and calculate the surface brightness distribution. The method is very flexible and can be applied to radiative transfer problems occurring not only in a single dust cloud, but also in extragalactic dust environment. We compare, for performance test, the result of Monte-Carlo simulation with the well-known analytic approximation for a spherically symmetric homogeneous cloud. We find that the Code approximation gives a very accurate result.
        4,000원
        13.
        2008.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We present analytical approximations for calculating the scattering and escape of non-ionizing photons from a plane-parallel medium with uniformly illuminated by external sources. We compare the results with the case of a spherical dust cloud. It is found that more scattering and absorption occur in the plane-parallel geometry than in the spherical geometry when the optical depth perpendicular to the plane and the radial optical depth of the sphere are the same. The results can provide an approximate way to estimate radiative transfer in a variety interstellar conditions and can be applied to the dust-scattered diffuse Galactic light.
        4,000원
        18.
        2019.10 서비스 종료(열람 제한)
        최근 정부의 미세먼지 특별법이 발효됨에 따라 비상저감조치 시행시 건설현장 및 공장 작업시간을 조정 및 단축하도록 권고하고 있지만 정량적인 기준 및 저감기술 부재로 인해 기업의 자발적 참여를 유도하는 수밖에 없는 실정이다. 또한 최근 도로포장 재료생산 플랜트에서 발생하는 비산먼지 및 유해가스로 인한 피해사례가 다수 발생하고 있으며 이로 인한 공장 주변 주민들과의 갈등이 심각한 실정이다. 이에 본 연구에서는 국내외 도로포장 관련 비산먼지 발생현황 및 관련법에 대한 조사를 수행하고, 도로포장 전주기(생산-시공-운영)에서의 단계별 발생량 조사를 통해 각 단계에 적합한 비산먼지 저감기술 개발 및 적용방안을 제시하고자 한다.