• 해양환경안전학회지
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• 제25권3호
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• pp.381-394
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• 2019

The marine industry contributes a large proportion of the air pollutant emissions along coastal regions, and this air pollution has been strongly linked to cardiovascular diseases and other illnesses. To alleviate the problem, many ports have installed alternative maritime power (AMP) facilities that enable onboard marine auxiliary engines with generators (gensets) to be shut down while a ship is at berth. This study compared the emissions from conventional gensets with those from AMP facilities, focusing on four emission types: greenhouse gases (GHG), sulphur oxides (SOX), nitrogen oxides (NOX), and particulate matter (PM). Both direct (combustion / operation) and indirect (upstream) emissions were considered together for the emission comparison. The results showed that AMP has lower emissions than conventional onboard gensets, and this benefit is highly dependent on the electricity generation mix onshore. On average, GHG emissions could be reduced by about 18.3 %, while the other emissions (SOX, NOX, and PM) would decrease more dramatically (88.4 %, 90.1 %, and 91.5 %, respectively). Additionally, future benefits of the AMP would increase due to the expansion of renewable energies. Thus, this study supports the potential of AMP as a promising solution for environmental concerns at ports worldwide.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2579-2585
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• 2022

Ceramics of quaternary garnets (Gd,Y)₃Al₂Ga₃O₁₂ doped with Ce, Tb have been fabricated and evaluated as prospective materials for indirect energy converters of α-and β-voltaic. Samples were characterized at excitation with an X-ray source and an intense 150 keV electron beam and showed good temperature stability of their emission and tolerance to irradiation. The role of X-rays accompanied the α-particle emitting in the increase of the conversion efficiency is clarified. The garnet-type structure of the matrix in the developed materials allows the production of quality crystalline mass with a light yield exceeding that of the commonly used YAG: Ce scintillator by a factor of two times.

• 한국자동차공학회논문집
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• 제13권3호
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• pp.87-95
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• 2005

Most of the motorcycle engines have used carburetors in the fuel system, because of its simple structure and reliability but the fuel economy and the emissions of those engines are bad when we compared with automobile engines .To meet with the tighten emission regulations and the higher requirements for fuel economy, the application of the carburetor on the motorcycle engines would be limited. Therefore, it is important to develope a ECU control system for motorcycle engines. Since the fuel injection system is expensive, it is necessary to decrease the cost of ECU system for motorcycle engines, but the accuracy of the ECU control system should be increased as high as possible. In this paper, we studied about the AFS characteristics of motorcycle engine controled by indirect method.

• 한국자동차공학회논문집
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• 제18권3호
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• pp.88-94
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• 2010

In this paper, the effect of the ultrasonic energy on the diesel engine's smoke reduction has been investigated for indirect injection diesel engine. The smoke concentration of the ultrasonically reformed diesel fuel was reduced remarkably in comparison with conventional diesel fuel. And in-cylinder pressure, heat release rate and mass fraction burned was improved but combustion duration was decreased. However, The combustion durations and the smoke concentrations of both diesel fuels were proportional to the increases of engine loads. Also, When the combustion duration has been increasing, the smoke emission has been augmenting in the shape of the exponential functions.

• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1503-1507
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• 2004

New synthetic methodology of the saturated and unsaturated Er(III)-chelated prototype complexes based on benzoate and pentafluorobenzoate ligands was developed through ligand-exchange reaction. The saturated 8-coordinated Er(III) complexes exhibit stronger near-IR emission than those of the unsaturated 6-coordinated Er(III) complexes, obtained from the direct photoexcitation of Er ions with 488 nm. Three $H_2O$ molecules coordinated in the unsaturated 6-coordinated complexes seriously quenched the near IR emission by the harmonic vibration relaxation decay of O-H bonds. Also, the stronger emission of the Er(III) complexes was obtained by the indirect photoexcitation of ligands than by the direct photoexcitation of the Er(III) ions, due to the energy transfer between the excited ligand and the erbium ion. Furthermore, the saturated Er(III)-chelated complex with C-F bonds shows much stronger near IR emission than that of the saturated Er(III)-chelated complex with C-H bonds. It is attributed to the influence of C-F bonds on near IR emission.

• 에너지공학
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• 제18권3호
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• pp.169-174
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• 2009

본 연구에서는 수송용 경유를 연료로 사용하고 있는 간접분사식 디젤기관에 있어서 연료에 초음파 에너지를 조사하였을 때의 기관성능 및 배출물질 특성 변화에 대해 조사하였다. 실험은 경유에 초음파 에너지를 조사한 연료와 상용 경유를 간접분사식 디젤기관에 적용하여 다음과 같은 결론을 얻었다. 본 운전조건하에서, 초음파 에너지를 조사한 경유로 디젤기관을 운전하였을 경우,상용 경유 운전 시에 비해 지압선도, 열발생율 및 출력이 상승하고 질량연소율이 단축되었으며 제동연료소비율과 매연은 감소하였다. 또한, 보다 안정화되면서 완전한 연소가 이루어졌으며 질소산화물은 증가하였다.

• 동력기계공학회지
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• 제9권3호
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• pp.15-20
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• 2005

In this paper, the effect of oxygen component in fuel on the exhaust emissions has been investigated for an indirect injection diesel engine. It was tested to estimate change of engine performance and exhaust emission characteristics for the commercial diesel fuel and oxygenated blended fuel which has four kinds of mixed ratio. And, the effects of exhaust gas recirculation(EGR) on the characteristics of NOx emission have been investigated. Ethylene glycol mono-n-butyl ether(EGBE) contains oxygen component 27% in itself, and it is a kind of effective oxygenated fuel of mono-ether group that the smoke emission of EGBE is reduced remarkably compared with commercial diesel fuel, that is, it can supply oxygen component sufficiently at higher loads and speeds in diesel engine. It was found that simultaneous reduction of smoke and NOx was achieved with oxygenated fuel(10vol-%) and cooled EGR method(10%).

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.125-126
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• 2022

As environmental problems around the world become serious, Korea has also raised the greenhouse gas reduction in the building sector to 32.8% compared to 2018, and efforts to reduce carbon in buildings are expanding. Recently, research is being actively conducted to reduce carbon in the long term by expanding the scope of greenhouse gas indirect emissions (Scope3), and even within the domestic Green Standard for Energy and Environmental Design(G-SEED) by quantitatively evaluating the environmental impact of buildings during the entire life cycle. However, it is difficult to accurately evaluate the carbon emission of the transportation process by assuming the material transport distance in the evaluation of the Life Cycle Assessment(LCA). Therefore, in this study, the main building materials of the building were selected through case evaluation and the carbon emission of the material transport process was derived based on the actual transport distance, and this was compared and analyzed with the theoretical LCA results.

• 환경영향평가
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• 제19권1호
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• pp.1-13
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• 2010

Ammonia ($NH_3$) is an important pollutant that plays a key role in several air pollution problems. It can create odors and have negative impacts on animal and human health. The largest source contributing to Ammonia emission is the agricultural production, in particular animal operation, in Korea. The present study evaluated flux profiles of Ammonia emitted from the cattle housing using a dynamic flux chamber. We have developed the emission factor of Ammonia from the cow housing. Analysis of Ammonia flux variation was made with respect to manure surface temperature, pH, and ammonium concentration. Ammonia has been measured from calf and cattle housing between October and December in 2007. In the fall, average Ammonia flux from calf and cattle housing was estimated 1.342(${\pm}0.728$) and 1.323(${\pm}0.655$)mg/$m^2$/min, respectively. In the winter, average Ammonia flux was estimated 0.889(${\pm}0.362$)mg/$m^2$/min from the calf housing and 0.925(${\pm}0.511$)mg/$m^2$/min from the cattle housing. The correlation coefficient between Ammonia flux and ammonium concentration showed stronger relationship than the relationship between manure pH and temperature. In the fall, Ammonia emission factor from calf and cattle housing was estimated 4.46(${\pm}2.39$) and 6.03(${\pm}3.27$)kg-$NH_3$/animal/yr, respectively. In the winter, average Ammonia flux was estimated 2.88(${\pm}1.53$) from the calf housing and 4.24({$\pm}1.63$)kg-$NH_3$/animal/yr from the cattle housing.

• 한국환경과학회지
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• 제29권7호
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• pp.729-737
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• 2020

This study estimates the greenhouse gas (GHG) emissions reduction resulting from photovoltaic and wind power technologies using a bottom-up approach for an indirect emission source (scope 2) in South Korea. To estimate GHG reductions from photovoltaic and wind power activities under standard operating conditions, methodologies are derived from the 2006 IPCC guidelines for national GHG inventories and the guidelines for local government greenhouse inventories of Korea published in 2016. Indirect emission factors for electricity are obtained from the 2011 Korea Power Exchange. The total annual GHG reduction from photovoltaic power (23,000 tons CO_2eq) and wind power (30,000 tons CO_2eq) was estimated to be 53,000 tons CO_2eq. The estimation of individual GHGs showed that the largest component is carbon dioxide, accounting for up to 99% of the total GHG. The results of estimation from photovoltaic and wind power were 63.60% and 80.22% of installed capacity, respectively. The annual average GHG reductions from photovoltaic and wind power per year per unit installed capacity (MW) were estimated as 549 tons CO_2eq/yr·MW and 647 tons CO_2eq/yr·MW, respectively. Finally, the results showed that the level of GHG reduction per year per installed capacity of photovoltaic and wind power is 62% and 42% compared to the CDM project, respectively.