• 실내환경 및 냄새 학회지
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• 제16권2호
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• pp.139-149
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• 2017

In order to reduce odor and methane emission from the landfill, open biocovers and a closed biofilter were applied to the landfill site. Three biocovers and the biofilter are suitable for relatively small-sized landfills with facilities that cannot resource methane into recovery due to small volumes of methane emission. Biocover-1 consists only of the soil of the landfill site while biocover-2 is mixed with the earthworm casts and artificial soil (perlite). The biofilter formed a bio-layer by adding mixed food waste compost as packing material of biocover-2. The removal efficiency decreased over time on biocover-1. However, biocover-2 and the biofilter showed stable odor removal efficiency. The rates of methane removal efficiency were in order of biofilter (94.9%)>, biocover-1(42.3%)>, and biocover-2 (37.0%). The methane removal efficiency over time in biocover-1 was gradually decreased. However, drastic efficiency decline was observed in biocover-2 due to the hardening process. As a result of overturning the surface soil where the hardening process was observed, methane removal efficiency increased again. The biofilter showed stable methane removal efficiency without degradation. The estimate methane oxidation rate in biocover-1 was an average of 10.4%. Biocover-2 showed an efficiency of 46.3% after 25 days of forming biocover. However, due to hardening process efficiency dropped to 4.6%. After overturn of the surface soil, the rate subsequently increased to 17.9%, with an evaluated average of 12.5%.

• 웰빙융합연구
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• 제4권2호
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• pp.19-25
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• 2021

Purpose: The purpose of this study is to reduce odor complaints by identifying problems with odor management at the site of the water regeneration center and researching odor management methods. Due to the high population density of Korea, sewage treatment facilities are adjacent to residential and industrial areas. According to previous studies, the main malodor-emitting facilities of sewage treatment facilities were preliminary treatment facilities (2,220 times), sedimentation basins (4,628 times), and sludge treatment facilities (9,616 times). Research design, data and methodology: Compound malodors and designated malodor-producing substances were collected from five site boundaries of the water regeneration center and analyzed according to the official methods to test malodor, and a total of two times (August and September 2020) were conducted. Results: As a result of the measurement, in the green area in front of the center office, compound malodors were detected at a maximum of 8 times and at least 3 times during the dawn time. As for the designated malodor-producing substances, 0.1ppm of ammonia was detected in the green area in front of the center office and the park golf course. This is within 15 times the maximum allowable emission level of compound malodors and within 1ppm of the maximum allowable emission level of ammonia. Conclusions: Even if the dilution rate of the compound malodors did not exceed the maximum allowable emission level, the odor could be recognized, and more research is needed in the future to establish effective reduction measures according to the subjective and individual and seasonal odor characteristics.

• 한국재료학회지
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• 제33권10호
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• pp.400-405
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• 2023

Tb³⁺-doped CaNb₂O₆ (CaNb₂O₆:Tb³⁺) thin films were deposited on quartz substrates at a growth temperature of 300 ℃ using radio-frequency magnetron sputtering. The deposited thin films were annealed at several annealing temperatures for 20 min and characterized for their structural, morphological, and luminescent properties. The experimental results showed that the annealing temperature had a significant effect on the properties of the CaNb₂O₆:Tb³⁺ thin films. The crystalline structure of the as-grown CaNb₂O₆:Tb³⁺ thin films transformed from amorphous to crystalline after annealing at temperatures greater than or equal to 700 ℃. The emission spectra of the thin films under excitation at 251 nm exhibited a dominant emission band at 546 nm arising from the ⁵D₄→⁷F₅ magnetic dipole transition of Tb³⁺ and three weak emission bands at 489, 586, and 620 nm, respectively. The intensity of the ⁵D₄→⁷F₅ (546 nm) magnetic dipole transition was greater than that of the ⁵D₄→⁷F₆ (489 nm) electrical dipole transition, indicating that the Tb³⁺ ions in the host crystal were located at sites with inversion symmetry. The average transmittance at wavelengths of 370~1,100 nm decreased from 86.8 % at 700 ℃ to 80.5 % at an annealing temperature of 1,000 ℃, and a red shift was observed in the bandgap energy with increasing annealing temperature. These results suggest that the annealing temperature plays a crucial role in developing green light-emitting CaNb₂O₆:Tb³⁺ thin films for application in electroluminescent displays.

• 한국멀티미디어학회논문지
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• 제15권2호
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• pp.234-241
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• 2012

최근 국내 공공기관 지방이전이 본격적으로 추진됨에 따라 영상회의 시스템의 활용과 중요성이 증대되고 있다. 영상회의 시스템은 출장으로 발생하는 온실가스 배출을 감소시키는데 중요한 역할을 할 것으로 기대되는 그린 IT 시스템이지만 이에 대한 경제적 효과 분석은 미비한 실정이다. 본 연구에서는 비용편익분석법을 활용하여 영상회의 시스템을 통한 온실가스 배출 감축 효과를 정량적으로 분석하였다. 한국정보화진흥원 19개 부서에 대한 설문결과를 바탕으로 투자비용 대비 경제적 효과를 추정하고 157개의 지방이전 공공기관으로 확대한 결과 영상회의 시스템 도입은 약 1,800억원의 경제적 효용이 있으며 향후 5년간 약 580톤에 달하는 이산화탄소를 감축할 수 있는 것으로 분석되었다. 본 연구의 결과는 유사산업 분야의 그린 IT 시스템 도입에 대한 의사결정시 경제적 타당성 평가를 위한 중요한 분석틀로 활용될 수 있을 것이다.

• 한국통신학회논문지
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• 제41권8호
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• pp.928-941
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• 2016

유선 데이터 네트워크(wired data network) 영역에서 가장 많은 에너지를 요구하는 영역은 액세스 네트워크(access network) 영역이다. 오늘날 그린 네트워킹(Green networking)은 유선 데이터 네트워크에서도 통합적인 에너지 관리를 통해 에너지 낭비와 $CO_2$ 배출 감소를 유도하기 위해 주요 관심분야가 되었다. 그러나 유선 액세스 네트워크의 에너지 소모량과 $CO_2$ 배출에 의한 환경적 영향에 대해서는 널리 알려져 있지 않으며, 그에 따른 범용적이고 정량적인 평가 기준도 매우 부족하다. 본 논문에서는 유선 액세스 네트워크의 에너지 소모량을 추정하는 기존의 모델링 기법들의 문제점을 비교 분석하고 하향식(top-down) 접근법을 이용하여 대규모 유선 액세스 네트워크의 에너지 소모량을 추정하는 모델링 기법을 제안한다. 또한 제안 모델로부터 도출된 추정치를 이용하여 액세스 네트워크들이 환경에 미치는 영향도를 산출하는 모델을 제안한다. 그리고 실제 사례를 적용하여 기존 모델과 제안 모델로부터 산출한 추정치와 해당 사례에 대한 기존의 조사와 실측 데이터와 비교 평가 한다.

• 한국산림과학회지
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• 제101권2호
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• pp.286-290
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• 2012

산불은 전 세계적으로 다량의 온실가스를 배출하여 지구온난화에 기여한다. 본 연구에서는 산불로 인한 지표층 연료의 연소량과 이로 인한 온실가스 배출량을 분석하고자 하였다. 이를 위해 51개 산불을 대상으로 소나무림과 활엽수림으로 구분하고, 다시 지표화와 수관화 피해 지역으로 나누어 잔존 연료량을 채취하여, 미연소 지역의 연료량과 일원분산분석을 수행하였다. 그 결과 활엽수 지표화 지역은 8,361 kg/ha, 소나무 지표화 지역은 8,055 kg/ha, 소나무 수관화 지역은 12,333 kg/ha이 연소되어, 수종별 산불행태별로 차이가 있었다. 이때의 연소율은 각각 78, 59, 90%이었다. 이산화탄소, 메탄, 아산화질소 등의 온실가스 배출량은 활엽수 지표화 연소지역 15,856 kg/ha, 소나무 지표화 연소지역 14,834 kg/ha, 소나무 수관화 연소지역은 약 22,709 kg/ha이었다.

• 한국자동차공학회논문집
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• 제25권2호
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• pp.207-218
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• 2017

Improving fuel consumption, particularly that of commercial vehicles, has become a global concern. The reduction in logistics cost has been a key issue in efforts to improve fuel economy and efficiency of transportation equipment. Typical technologies for reducing reduce fuel usage include air resistance reduction technologies, tire rolling resistance technologies, and idle technologies among others. Air resistance technology is a highly effective method that can be easily applied in a short period. As with air resistance technology, several devices involving side skirt, boat tail and gap fairing have been developed based on an analytical 3-D modeling technique for reducing air resistance attributed to the vehicle configuration. The devices were on a 45 feet tractor-trailer and the emission test was done using PEMS equipment. Fuel economy was evaluated by introducing several devices to reduce outer air resistance. The test was conducted by changing the experimental method of SAE J1321 Joint TMC/SAE Fuel Consumption Test Procedure - Type II test. As a result, air resistance decreased by at least 15 % and fuel economy improved by at least 13 %. This study sought to reduce greenhouse gas and improve fuel economy by applying several devices to a test vehicle to lower air resistance.

• 신재생에너지
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• 제6권2호
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• pp.27-32
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• 2010

Low Calorific Gas Turbine (LCGT) has been developed as a next generation power system using landfill gas (LFG) and biogas made from various organic wastes, food Waste, waste water and Livestock biogas. Low calorific fuel purification by pretreatment system and carbon dioxide fixation by green house system are very important design target for the optimum applications of LCGT. Main troubles of Low Calorific Gas Turbine system was derived from the impurities such as hydro sulfide, siloxane, water contained in biogas. Even if the quality of the bio fuel is not better than natural gas, LCGT may take low quality gas fuel and environmental friendly power system. The mechanical characterisitics of LCGT system is a high energy efficiency (>70%), wide range of output power (30 kW - 30 MW class) and very clean emission from power system (low NOx). A green house has been designed for four different carbon dioxide concentration from ambient air to 2000 ppm by utilizing the exhaust gas and hot water from LCGT system. LCGT is expected to contribute achieving the target of Renewable Portfolio Standards (RPS).

• 한국태양에너지학회 논문집
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• 제23권1호
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• pp.57-67
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• 2003

This study aims to presents Evaluation Method of Green Remodeling that analyze the value of environment through expense, using the method of life cycle cost and life cycle assessment simultaneously. The results of this study are summarized as follows. Evaluation Model developed in this study can convert economical value of environment into cost by integrating. In addition, the model can apply as a useful tool to estimation of economical design alternative as well as quantification of environmental loads and costs. Evaluation Model presented In this study observe energy consumption and the environmental load emission with qualification, it can forecast effect of environmental cost that cost estimation is expected to be added to energy cost rate by being possible. Synthetically, when Estimation Model and computer program that developed in this study is applies to the construction industry; reasonable management of environmental load is convenient at each step of Green Remodeling. In addition, at preliminary design phase, practical use may be possible by reasonable yardstick about various alternatives and improvement of design alternatives likewise by grasping environmental effect.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.546-546
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• 2013

Zinc silicate ($Zn_2SiO_4$) has been identified as a suitable host material for a wide variety of luminescent activators, such as transition metal and rare earth elements. In particular, manganese-activated $Zn_2SiO_4$ exhibits highly efficient photoluminescenceand cathodoluminescence, which allows this material to be used in fluorescent lamps and display applications. In this study, we investigated the green and yellow luminescence from Mn-doped $Zn_2SiO_4$ thin films that were synthesized using radio frequency magnetron sputtering followed by annealing at $600{\sim}1,200^{\circ}C$ The refractive index of the $Zn_2SiO_4$: Mn films showed normal dispersion behavior. It was found that the $Zn_2SiO_4$: Mn films annealed at $800^{\circ}C$ ossessed a mixture of alpha and beta phases. The obtained photoluminescence spectrum consisted of two emission bands centered at 525 nm in the green range and 574 nm in the yellow range. The green luminescence originates from the divalent Mn ions in alpha phase of $Zn_2SiO_4$, while the yellow luminescence comes from the divalent Mn ions in beta phase. The films annealed at and above $900^{\circ}C$ xhibited only the alpha phase. The broad PL excitation band was observed ranging from 220 to 300 nm with a maximum at around 243 nm.