• 분석과학
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• 제30권5호
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• pp.240-251
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• 2017

1,1,1,2-수소불화탄소(HFC-134a)는 에어컨에 주로 사용되는 냉매로, 최근 온실가스로 규제되어 정제를 통한 재사용 방법이 권장되고 있다. 폐냉매의 재사용 기준 평가를 위해서는 폐냉매에 존재하는 미량 성분의 정량분석이 매우 중요하다. 본 연구에서는 표준 물질이 없어서 정량화하기 어려웠던 C, H, Cl, F가 포함된 미량 성분들을 GC/AED (gas chromatograph-atomic emission detector)를 이용하여 정량분석하였다. 이를 위하여 GC/MSD (mass selective detector)를 통한 정성분석을 선행하였다. 또한 성분의 원자 수와 비례하여 반응하는 AED의 특성을 조사하기 위하여, 탄화수소 혼합 표준물질을 이용하여 선형성을 확인하였다. 시료 중 C, H, Cl, F가 포함된 미량 성분의 정성 분석 결과, 주성분인 HFC-134a와 유사 냉매류들을 포함한 총 15 개의 성분이 검출되었다. MSD 결과를 토대로 AED를 이용한 미량 성분들을 정량 분석한 결과, 한 시료는 $CHClF_2$ 성분($45438.38{\mu}mol/mol$), 또 다른 시료는 $C_2H_2ClF_3$ 성분($1311.47{\mu}mol/mol$)이 가장 높은 몰분율을 나타냈다. 본 연구에서는 이 분석법을 기반으로 하여, 표준 물질이 존재하지 않아 정량화하기 어려운 복합 성분들의 정성 및 정량 분석의 확장 적용이 가능할 것으로 보인다.

• 대한환경공학회지
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• 제32권10호
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• pp.957-964
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• 2010

경유차 배출가스에 의해 활성이 크게 저하된, 촉매가 담지된 자연 재생식 매연 저감장치인 DPF를 대상으로 여러 가지 조건에서 재제조를 수행한 후 재제조된 DPF의 일산화탄소(CO)와 총 탄화수소(THC) 그리고 입자상 물질(PM)의 저감효율과 DPF 표면 물성 특성을 분석하여 사용후 DPF에 대한 재제조 효과를 관찰하였다. 재제조된 DPF에 대한 오염물질 저감성능 평가는 제작된 디젤 엔진 다이나모 장치를 이용, 배기가스를 일부 우회시켜 온도와 공간속도 조절이 가능한 촉매 반응장치로 수행 하였으며, DPF 표면 물성 분석은 광학현미경, EDX, ICP, TGA 그리고 porosimeter를 이용 하였다. 연구 수행 결과 사용 후 DPF를 본 연구에서 적용된 고온 배소 세정, 산성/염기성 용액에 의한 초음파 세정, 세정 후 촉매 활성성분 재 함침에 의한 재제조를 수행할 경우, 재제조된 DPF의 성능이 신품 성능대비 95% 이상으로 회복되는 것을 확인 하였으며, 광학현미경, EDX, TGA와 ICP등의 분석을 통해 본 연구 조건에서의 재제조 과정으로, DPF의 활성저하 원인이 되었던 각종 불순성분 대부분이 사용후 DPF 표면으로 부터 제거되는 것을 확인 하였다.

• Journal of Preventive Medicine and Public Health
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• 제6권1호
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• pp.27-41
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• 1973

In order to provide some basic data for the control of air and water pollution in Korea, the authors have estimated the amount of air and water pollutants emitted from industries which are employed over 20 employees. This study have done from July 1, 1972 to the end of March 1973. The results are as followings; 1. Total number of establishments with over 20 employees is 5,197 in Korea and the largest group establishments was the manufacturing of textiles with 1,363 establishments (26.2%). 2. By order of number of employees it was observed that there 2,800 industries with 20-59(53.9%) employees, 1,101 with 50-99 (21.2%), 571 with 100-199 (11.0%), 501 with 200-499 (9.6%) and 225 with over 500 (4.3%) respectively. 3. By order of regional distribution, it was observed that there were 2,257 industries in Seoul (43.2%) and 736 industries in Pusan(14.2%). 4. Industrial coal consumption was 596,154 M/T in 1972, but it' 11 be 315,000 M/T in 1980. Fuel consumption was 4,972,000 K1 in 1972, and estimated volume will be 19,370,000 K1 in 1980. 5. Total amounts of air polutants entitled from industries by fuel combustion were sulfur oxides 79,459 tons, carbon monoxide 33,908 tons, particulate 31,304 tons and hydrocarbon 30,280 tons in 1972 but in 1990 there will be sulfur oxides 1,010,474 tons, nitrogen oxides 204,575 tons, carbon monoxide 68,014 tons, particulate 64,820 tons and hydrocarbon 67,622 tons, respectively. 6. Annual emitted air pollutants through the working processes were sulfur oxides 91,250 tons and nitrogen oxides 32,485 tons in 1972, but sulfur oxides 118,625 tons and nitrogen oxides 42,555 tons will be present in 1980, respectively. 7. Annual emitted air pollutants by national unit area amounted to $0.77ton/km^2/year$ in 1965 and $14.7ton/km^2/year$ in 1980. 8. Total industrial wastes from all industries in Korea were estimated at 810,360 tons/day in 1972; manufacturing of chemicals and plastic products showed the highest amount of wastes at 470,000 tons/day. 9. The amounts of water pollutants due to industrial wastes were the B.O.D., 471.5 tons/day, suspended solid 331.5 tons/day, CN, 2.3 tons/day, and Cr. 3.4 tons/day in 1972, but it might be evident of a B.O.D. of 3,388 tons/day, suspended solid 2,544 tons/day, CN 20.1 tons/day, and 26.5 tone/day in 1990. 10. Total population equivalent of B.O.D. was 943,000 in 1972, and the estimated value in 1950 will be 6,780,000.

• Korean Chemical Engineering Research
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• 제52권5호
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• pp.672-677
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• 2014

반탄화는 $200{\sim}300^{\circ}C$의 불활성분위기에서 바이오매스를 전처리하는 열처리공정이며 이러한 반탄화 공정은 바이오 매스에 함유된 섬유질성분의 분해온도에 크게 영향을 받은 것으로 알려져 있다. 본 연구에서는 사탕수수 부산물의 반탄화 특성에 관한 연구를 수행하였으며 반탄화 온도 및 반탄화 시간에 따른 에너지 수율, 발열량 및 발생가스 그리고 가연분과 회분의 관계에 중점을 두었다. 또한 본 연구에서는 TGA(Thermogravimetric Analyzer)를 이용한 사탕수수 부산물의 반탄화 반응에 대한 활성화 에너지의 변화도 함께 고찰하였다. 본 연구로부터 반탄화 온도에 따라 회분 및 발열량은 증가하였으나 가연분 및 에너지 수율은 감소하였으며 또한 산소성분을 함유한 일산화탄소가 탄화수소 화합물, $C_xH_y$ 보다 더 낮은 온도에서 분해되기 시작하는 것을 확인할 수 있었다.

• 공업화학
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• 제25권5호
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• pp.510-514
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• 2014

본 연구에서는 고형연료로써의 에너지 잠재성을 평가하기 위하여 하수슬러지의 기본특성에 대한 반탄화의 영향을 고찰하였으며, 이를 위하여 $150{\sim}600^{\circ}C$의 온도조건에서 하수슬러지의 반탄화 실험을 수행하였다. 반탄화된 하수슬러지는 에너지 수율, 회분, 가연분 및 고위발열량에 의하여 분석되었으며, 반탄화 과정에서 발생되는 가스성분 또한 분석하였다. 또한 본 연구에서는 하수슬러지의 반탄화 반응에 대한 속도론적 해석을 위하여 열중량 분석을 수행하였다. 본 연구로부터 반탄화 온도가 증가함에 따라 회분함량은 증가하는 반면에 에너지 수율, 고위발열량 및 가연분은 감소하는 것으로 나타났으며, 또한 $300^{\circ}C$에서 하수슬러지 내에 함유된 가연성 성분의 열분해로 인하여 일산화탄소 및 탄화수소 가스가 발생하기 시작함을 확인할 수 있었다.

• 천문학논총
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• 제27권4호
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• pp.209-212
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• 2012

We present the results of the near-infrared (NIR) to mid-infrared (MIR) slit spectroscopic observations of the diffuse emission toward nine positions in the nearby irregular galaxy Large Magellanic Cloud (LMC) with the Infrared Camera (IRC) on board AKARI. The unique characteristic of AKARI/IRC provides a great opportunity to analyze variations in the unidentified infrared (UIR) bands based on continuous spectra from 2.5 to $13.4{\mu}m$ of the same slit area. The observed variation of $I_{3.3}/I_{11.3}$ suggests destruction of small-sized UIR band carriers, polycyclic aromatic hydrocarbons (PAHs) in harsh environments. This result demonstrates that the UIR $3.3{\mu}m$ band provides us powerful information on the excitation conditions and/or the size distribution of PAHs, which is of importance for understanding the evolutionary process of hydrocarbon grains in the Universe. It also suggests a new diagnostic diagram of two band ratios, such as $I_{3.3}/I_{11.3}$ versus $I_{7.7}/I_{11.3}$, for the interstellar radiation conditions. We discuss on the applicability of the diagnostic diagram to other astronomical objects, comparing the LMC results with those observed in other galaxies such as NGC 6946, NGC 1313, and M51.

• 한국수소및신에너지학회논문집
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• 제21권6호
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• pp.519-525
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• 2010

Ethanol was used as reductant to remove $NO_x$ over Ag/$Al_2O_3$ catalyst via SCR from stationary emission source. Among the tested hydrocarbon reductants, ethanol showed highest de-$NO_x$ performance over the Ag/$Al_2O_3$ catalyst. De-$NO_x$ efficiency of about 83% was obtained in the condition of GHSV 20,000 $hr^{-1}$, $NO_x$ 200 ppm, CO 200 ppm, $O_2$ 13%, $H_2O$ 5% and mole ratio of ethanol/$NO_x$ = 2 between temperature of $300^{\circ}C$ and $400^{\circ}C$. While $SO_2$ presence in the $NO_x$ exhaust suppressed the catalytic activity, catalyst with acid (0.7% $H_2SO_4$) treatment of catalyst showed higher catalytic activity, where In-Situ DRIFT showed S presence over catalyst surface was increased after acid treatment of catalyst. From in-situ DRIFT and SCR results, it was concluded that sulfur presence over the surface of Ag/$Al_2O_3$ catalyst was the dominant factor to control the de-$NO_x$ reaction yield via HC-SCR from the exhausted gas including $SO_2$.

• 한국대기환경학회지
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• 제30권1호
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• pp.77-87
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• 2014

In this study, an experimental approach to measure a suite of low weight hydrocarbons was investigated with an emphasis on ethylene (EL) along with many others (ethane (EA), propane (PA), propylene (PL), n-butane (BA), acetylene (AL), methyl acetylene (ML)). Their concentrations were quantified using GC-FID system equipped with thermal desorption (TD) system. The TD-based analysis was conducted using both Link Tube/Thermal Desorber (LT/TD) method and Modified Injection through a Thermal Desorption (MITD) method. The results of these analyses were evaluated in a number of respects. The system allowed the detection of all compounds except methane with the mean response factor (RF) of 10.28 (EA) to 11.94 (PL). The method detection limits of target compounds were seen in the range of 0.027 (ML) to 0.146 ng (BA). The emission flux of some environmental samples (fruits), when measured using a small flux chamber system, fell in the range of 0.14 (AL: Kiwi) to $181ng{\cdot}g^{-1}{\cdot}hr^{-1}$ (EL: Apple Peel). The results of this study confirm that the experimental approach developed in this study allows to accurately measure emissions of low weight hydrocarbons (LWHC) like ethylene from various natural and man-made source processes.

• 대한기계학회논문집B
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• 제27권11호
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• pp.1548-1562
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• 2003

This paper is the first of several companion papers which compare the methods of Air-fuel ratio determination. There are many methods which calculate Air-Fuel ratio from exhaust emission. Most of them are based on the simple chemical equations, which use balance of atom, and the error of the calculation is negligible as far as the instrumentation accuracy is guaranteed. They assume homogeneous mixture and complete combustion to the extent of oxygen availability. Because of these simple assumptions, they cannot offer the information about the fuel distribution state and the malfunction of instrument. For these limitations, Eltinge offered new one based on stricter mathematical model. This result coincides with the others very well and gives more information about the mixture state and instrumentation. Consequently this might be a general solution for Air-fuel ratio determination and exhaust composition. The objects of the calculation, however, were not commercial fuels except gasoline and the compensation method of unburned hydrocarbon was not appropriate to recent analyzer. Moreover he did not consider the fuel which contains oxygen, such as methanol, ethanol and blend of gasoline-alcohol. In this paper, Eltinge chart is expanded to the arbitrary fuel composition as the reference exhaust compositions for the purpose of further discussions about Air-fuel ratio determination methods and the charts fur gasoline, diesel, methanol, M85, liquefied petroleum gas(LPG), natural gas(NG), propane, butane are illustrated.

• 한국자동차공학회논문집
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• 제25권3호
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• pp.380-388
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• 2017

Wood pyrolysis oil(WPO) has been regarded as an alternative fuel for diesel engines. However, WPO is not feasible for use directly in diesel engines due to its poor fuel quality such as low energy density, high acidity, high viscosity and low cetane number. The most widely used approach to improve WPO fuel quality is to blend WPO with other hydrocarbon fuels that have a higher cetane number. However, WPO and fossil fuels are not usually blended because of their different polarity. Also, clogging and polymerization problems in the fuel supply system can occur when the engine is operated with WPO. Polymerization can be prevented by diluting WPO with other alcohol fuels. However, WPO-alcohol blended fuel does not produce self-ignition. Therefore, additional cetane enhancement to the blended fuel is required to enhance auto-ignitability. In this study, WPO was blended with n-butanol and two cetane enhancements(PEG 400 and 2-EHN) for application to a diesel generator. Experimental results showed that the WPO-butanol blended fuel achieved a very stable engine operation under maximum WPO content of 20 wt%.