• 한국응용과학기술학회지
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• 제32권4호
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• pp.649-660
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• 2015

Calpuff 역모델링 기법을 이용해 산출된 자료는 오염물질 발생량을 예측할 수 있으며, 여러 가지 자료 비교를 통해 감축 가능성 및 목표 수립이 가능해졌다. 본 연구에서는 동해항 주변지역을 대상으로 Calpuff 역모델링 기법을 이용하여 대기 중 미세먼지 저감량 설정하기 위한 기초자료 구축에 목적을 두었으며, 모델링을 이용한 동해항을 포함한 5개 지역 배출농도 산출결과는 다음과 같다. 대기환경기준인 $50{\mu}g/m^3$을 적용하여 대상 지역별 허용배출량 산출 결과 site-D에서 가장 많은 $4.95{\mu}g/m^2{\cdot}S$의 배출량 저감이 요구되었으며, $4.95{\mu}g/m^2{\cdot}S$의 배출량을 감소시킬 경우 영향예측지점(동해하수종말처리장)의 PM10 평균 예측농도는 $42.6{\mu}g/m^3$로 감소될 것으로 나타났다. site-A(동해항)에서 배출되는 오염물질만을 적용하여 모델링 진행 결과 동해항 주변 민가의 기여농도는 평균 $40{\sim}50{\mu}g/m^3$으로 나타났으며, 배경농도를 고려하면 대기환경기준인 $50{\mu}g/m^3$을 상회 할 것으로 예상됨에 따라 더 이상의 오염물질 배출량은 허용되지 않을 것으로 판단된다. site-B는 상가와 나대지로 차량 통행과 나대지에서 비산되는 먼지로 인해 $0.11{\mu}g/m^2{\cdot}S$의 배출량 저감이 요구되었으며, site-C와 E는 오염물질 저감량은 발생하지 않았으나 지속적인 관리가 요구된다.

• 환경영향평가
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• 제30권4호
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• pp.237-246
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• 2021

경기도 도시대기측정망의 시간별 PM₁₀과 PM_2.5 농도에 대하여 측정소별로 상관성을 분석하여 측정소별 미세먼지 농도자료의 유사성을 파악해보았다. 미세먼지 경보제를 위해 사용되고 있는 기존의 권역구분을 그대로 이용했을 때, 동일한 권역 내의 측정소들은 PM₁₀의 경우 0.68, PM_2.5는 0.70 이상의 피어슨 상관계수 값을 보였으나, 일부 측정소는 타 권역과 높은 상관성(예, 0.80 이상)을 보여주고 있었다. 또한, 현재 구분하고 있는 권역은 주로 고농도 사례 횟수에 따른 군집분석 결과와 지리적 요인 등을 복합적으로 고려하여 결정된 것이므로, 미세먼지 관리를 위해서는 농도 특성에 따라 권역을 재분류할 필요성이 있다. 따라서 본 연구에서는 다차원척도법을 이용하여 미세먼지의 시간별 농도변화와 지역별 배출 기여율을 고려한 재범주화를 진행할 수 있었고, 이를 시각적으로 도시화할 수 있었다. 그 결과, PM₁₀은 5개의 권역으로 분류되고, PM_2.5는 4개의 권역으로 구분되었다.

• 환경영향평가
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• 제32권5호
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• pp.318-337
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• 2023

본 연구는 시스템다이내믹스를 활용하여 미세먼지 저감 정책이 미세먼지 농도와 건강에 미치는 영향을 살펴보았다. 시스템다이내믹스는 미세먼지 발생원, 저감 정책, 미세먼지 농도, 건강영향 간의 동태적이며 순환적인 관계의 모델링을 구축할 수 있는 장점이 있다. 연구에서는 국내의 대표적 미세먼지 저감 정책인 산업부문 미세먼지 배출규제, 디젤차 규제, 전기차 확대, 공원·녹지면적 확대를 대상으로 정책 시나리오를 작성하여 현재 추세가 유지될 때와의 2030년 기준 결과를 비교하였다. 분석 결과, 전기차 지원정책은 0.21㎍/m³의 PM₁₀ 농도 저감과 494명의 순환기계 질환자 수 감소 효과가 있었으며 전국적으로 고르게 효과가 나타났다. 산업 배출량 규제 시나리오에서는 0.22㎍/m³의 가장 높은 PM₁₀ 농도가 감소하였으나 전기차 지원보다 적은 질환자 수 감소 효과(358명)가 나타났는데 이는 해당 정책이 충북 단양군, 부산 사하구 등 일부 공업지역을 중심으로 높은 미세먼지 저감 효과를 보였기 때문이다. 이러한 결과는 지역의 배출원 특성에 맞는 정책 선정의 필요성을 제시하였다.

• 한국산업보건학회지
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• 제3권1호
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• pp.110-126
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• 1993

Worker exposures to total chromium, hexavalent chromium (VI), sulfuric acid and alkaline dust at electroplating operations and worker exposures to trichloroethylene (TCE) and methyl chloroform (MCM) at degreasing operations in eleven small industrial plants were evaluated. Appropriate local exhaust ventilation systems for both operations were designed and recommended. Results of the study are summarized as follows ; 1. Out of 134 measurements for airborne hexavalent chromium concentrations, seven were exceeding the Korean occupational health standard of $50{\mu}g/m^3$ and 45 were exceeding the NIOSH standard of $1{\mu}g/m^3$. With an exception of one measurement, concentrations of total chromium were below the Korean standard of $500{\mu}g/m^3$. 2. Worker exposures to chromium were closely related to the existing control methods at the electroplating operations. Local exhaust systems, partial coverage of the tank surface, and antifoaming agents on liquid surface were adopted as control methods. 3. With an exception of one sample, airborne concentrations of sulfuric acid and alkaline dusts were below the applicable occupational heatlth standards. 4. Three plants indicated that airborne concentrations of TCE and MCM were exceeding the Korean standards. Other plants showed lower concentrations than the standards. It should be noted that generally, the activities and workloads on the day of surveys were less than normal. 5. Since the most existing ventilation systems did not satisfy the ACGIH criteria, the ventilation systems should be improved. Some examples for designing appropriate ventilation systems are presented.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2327-2332
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• 2007

This study investigates on the inhalation force improvements of hood consisted one of the local ventilation systems attached the new device named as gas-guidance-device for removed a pollution source. The numerical method applying finite element method is calculated the velocity and pressure distributions of a moving fluid at the beginning and the inside of a hood with and without the gas-guidance-device in hood. And, the experimental study is measured the wind velocity using the anemometer at the same condition of numerical study. Also, the optimum shape of gas-guidance-device which is suitable for hood shape derived from the numerical and experimental results. The results of this study is supplied the important data to an industrial field for control of a pollution source in the engineering aspect. Moreover, the introduced technique of hood attached the gas-guidance-device is very useful to remove the harmful materials such as dust and waste happened in the manufacturing factory.

• Asian Journal of Atmospheric Environment
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• 제8권3호
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• pp.115-125
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• 2014

In this study, particle composition data for $PM_{10}$ samples were collected every 3 days at Seoul, Korea from August 2006 to November 2007, and were analyzed to provide source identification and apportionment. A total of 164 samples were collected and 21 species (15 inorganic species, 4 ionic species, OC, and EC) were analyzed by particle-induced x-ray emission, ion chromatography, and thermal optical transmittance methods. Positive matrix factorization (PMF) was used to develop source profiles and to estimate their mass contributions. The PMF modeling identified nine sources and the average mass was apportioned to secondary nitrate (9.3%), motor vehicle (16.6%), road salt (5.8%), industry (4.9%), airborne soil (17.2 %), aged sea salt (6.2%), field burning (6.0%), secondary sulfate (16.2%), and road dust (17.7%), respectively. The nonparametric regression (NPR) analysis was used to help identify local source in the vicinity of the sampling area. These results suggest the possible strategy to maintain and manage the ambient air quality of Seoul.

• 천문학논총
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• 제27권4호
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• pp.275-279
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• 2012

We investigate the mid-infrared (MIR) to far-infrared (FIR) properties of a nearly complete sample of local active galactic nuclei (AGNs) detected in the Swift/Burst Alert telescope (BAT) all-sky hard X-ray (14-195 keV) survey, based on the cross correlation with the infrared survey catalogs of AKARI, IRAS and WISE. Out of 135 non-blazar AGNs in the Swift/BAT 9-month catalog, we obtain the MIR photometric data for 128 sources in either the 9, 12, 18, 22, and $25{\mu}m$ band. We find a good correlation between their hard X-ray and MIR luminosities ranging three orders of magnitude (42 < log ${\lambda}L_{\lambda}$(9, $18{\mu}m$) < 45), which is tighter than that with the FIR luminosities at $90{\mu}m$. Both X-ray unabsorbed and absorbed AGNs follow the same correlation, implying isotropic infrared emission, as expected in clumpy dust tori models rather than homogeneous ones.

• 천문학회보
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• 제39권2호
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• pp.58.1-58.1
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• 2014

Energetic gas outflows from active galactic nuclei (AGNs) may have a crucial role in galaxy evolution. In this contribution, we present a census of ionized gas outflows using a large sample (~23,000) of local (z < 0.1) type-2 AGNs selected from the Sloan Digital Sky Survey DR 7. By measuring the velocity offset of narrow emission lines, i.e., [O III] ${\lambda}5007$ and the Balmer lines, with respect to the systemic velocity measured from the stellar absorption lines, we find ~47% of AGNs showing an [O III] line-of-sight velocity offset ${\geq}20km\;s-1$. The fraction in type-2 AGNs is similar to that in type-1 AGNs after considering the projection effect. AGNs with larger [O III] velocity offsets, in particular with no or weak $H{\alpha}$ velocity offsets, tend to have higher Eddington ratios, implying that the [O III] velocity offset is related to on-going black hole activity. Also, we find the different distributions of the host galaxy inclination between the AGNs with blueshifted [O III] and the AGNs with redshifted [O III], supporting the model of biconical outflow with dust obscuration. Meanwhile, for ~3% of AGNs, [O III] and $H{\alpha}$ exhibit comparable large velocity offsets, suggesting a more complex gas kinematics than decelerating outflows in the narrow-line region.

• 천문학회보
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• 제42권1호
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• pp.38.3-39
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• 2017

The N159 and N160 ionized regions in the Large Magellanic Cloud are an important extragalactic star-forming complex. The physical environments and the star formation stages are different in N159 and N160. We performed near-infrared polarimetry to those star forming regions with IRSF/SIRPOL 1.4-m telescope. Near-infrared polarization enabled us to trace the detailed structure of magnetic fields in star-forming regions. Through the polarimetric data of J, H, and Ks bands, we examined the magnetic field structures in the N159/N160 complex. In this presentation, we show complex distribution of the magnetic fields associated with dust and gas structures. We verify the local magnetic fields in each star-forming region, which appear to be related with local environments, such as interior and boundary of shell structure, star-forming HII regions, and boundaries between HII regions and dense dark clouds. We discuss the formation scenario of the N159/N160 complex suggested from the magnetic field structure.

• 천문학회보
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• 제36권2호
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• pp.55.1-55.1
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• 2011

Luminous infrared galaxies (LIRGs; $L_{IR}$ > ${10^{11}}_{Lsun}$) are the most powerful objects in the local Universe. Previous work suggested that dust re-processing of starburst and/or active galactic nuclei (AGN) activity, triggered by galaxy interactions, is responsible for their enormous infrared emission. To understand the nature of LIRGs, it is essential to determine their spectral types. Optical spectral types of 115 ultraluminous infrared galaxies in the southern sky are presented using CTIO observations. The AGN fraction is on average 50% and increases with infrared luminosity. Near-infrared spectral types of 36 LIRGs are also presented based on AKARI observations. In the sample, 12 optically elusive buried AGNs are found. To investigate the evolutionary sequence of LIRGs, star formation histories of ~6000 LIRGs in the SDSS and IRAS/AKARI matched sample are derived by comparing observed optical spectra and stellar population models. AGN-dominated LIRGs are currently massive relative to starburst-dominated LIRGs, which originates from an enhancement of star formation at intermediate-ages. For ~1100 early-type LIRGs, optical and NIR fundamental planes (FPs) are constructed. The FP of LIRGs is significantly different from that of normal early-type galaxies, but the difference is minimized in low luminous and AGN-like LIRGs. These findings support that the importance of AGN is growing as infrared luminosity increases and that LIRGs follow at least in the high mass regime the standard evolutionary scenario: starburst LIRGs evolve into AGN LIRGs and finally into normal early-type galaxies.