• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.6
• /
• pp.1185-1194
• /
• 2011

This study was carried out to estimate carbon emission using LCA (Life Cycle Assessment) and to establish LCI (Life Cycle inventory) DB for lettuce production system in protected cultivation. The results of data collection for establishing LCI DB showed that the amount of fertilizer input for 1 kg lettuce production was the highest. The amounts of organic and chemical fertilizer input for 1 kg lettuce production were 7.85E-01 kg and 4.42E-02 kg, respectively. Both inputs of fertilizer and energy accounted for the largest share. The amount of field emission for $CO_2$, $CH_4$ and $N_2O$ for 1 kg lettuce production was 3.23E-02 kg. The result of LCI analysis focused on GHG (Greenhouse gas) showed that the emission value to produce 1 kg of lettuce was 8.65E-01 kg $CO_2$. The emission values of $CH_4$ and $N_2O$ to produce 1 kg of lettuce were 8.59E-03 kg $CH_4$ and 2.90E-04 kg $N_2O$, respectively. Fertilizer production process contributed most to GHG emission. Whereas, the amount of emitted nitrous oxide was the most during lettuce cropping stage due to nitrogen fertilization. When GHG was calculated in $CO_2$-equivalents, the carbon footprint from GHG was 1.14E-+00 kg $CO_2$-eq. $kg^{-1}$. Here, $CO_2$ accounted for 76% of the total GHG emissions from lettuce production system. Methane and nitrous oxide held 16%, 8% of it, respectively. The results of LCIA (Life Cycle Impact assessment) showed that GWP (Global Warming Potential) and POCP (Photochemical Ozon Creation Potential) were 1.14E+00 kg $CO_2$-eq. $kg^{-1}$ and 9.45E-05 kg $C_2H_4$-eq. $kg^{-1}$, respectively. Fertilizer production is the greatest contributor to the environmental impact, followed by energy production and agricultural material production.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2001.11a
• /
• pp.360-361
• /
• 2001

VOCs 배출원은 크게 인위적인 배출원과 자연적인 배출원으로 나눌 수 있다. 식물은 자연 발생적 VOCs(NVOCs)의 가장 주요한 배출원이며, 대기 중으로 유입되는 반응성이 강한 탄소의 주요한 배출원이다. 이소프린, terpene, 알콜, 카르보닐화합물, 에스테르 등은 식물에서 발생되는 대표적인 탄화수소화합물들이다. 이러한 물질들은 에어로졸의 형성 등 전지구적 대기화학반응, 광역적 광화학산화제 (특히 오존)의 형성, 탄소순환의 수지균형 비도시지역의 산성침적에 기여하는 유기산의 생성 등에 주요한 영향을 끼친다. (중략)

• Cement Symposium
• /
• s.49
• /
• pp.21-22
• /
• 2022

The purpose of this study is to reduce carbon dioxide emissions in the cement industry and to collect carbon dioxide generated in industrial facilities such as cement factories and thermal power plants, store and utilize it, and convert high-value-added resources. While conventional Ordinary Portland Cement is characterized by hardening through hydration reactions, basic research is underway to develop cement that reacts with carbon dioxide and converts it into carbonate mineralization.

• Proceedings of the Korea Contents Association Conference
• /
• 2012.05a
• /
• pp.107-108
• /
• 2012

본 논문은 건설산업의 신뢰성 있는 온실가스 추정을 위해 건설단계에서 사용되는 장비, 자재 및 에너지 사용량에 따른 온실가스 배출량 추정방법론을 고찰하였다. 그리고 온실가스 배출량 추정모델인 Road Construction Emission Model과 시설물탄소배출량 산정 프로그램을 비교분석하였다. 건설장비만을 고려한 배출량 추정은 사용장비의 각종 특성에 따라 차이가 발생할 수 있고, 자재 및 에너지사용에 따른 배출량 추정은 장비의 사용이 대부분을 차지하는 토목공사에서 배제한 단점이 있다. 따라서, 건설산업의 온실가스배출량 측정은 장비의 사용 또는 자재 및 에너지사용에 따른 포괄적인 온실가스 배출량 추정과 이를 위한 기반확충이 이루어져야 한다.

• Korean Journal of Ecology and Environment
• /
• v.39 no.4 s.118
• /
• pp.435-444
• /
• 2006

A suite of extracellular enzyme activities involved in organic carbon decomposition were determined in three northern peatlands (a bog, a fen, and a swamp) over a 12 month period along with trace gas ($CO_2$ and $N_2O$) flux and DOC dynamics in the wetlands. The activities varied $0.008-0.066\;{\mu}mole\;g^{-1}\;min^{-1}$, $0.003-0.021\;{\mu}mole\;g^{-1}\;min^{-1}$, $0.003-0.016\;{\mu}mole\;g^{-1}\;min^{-1}$, $0.004-0.047\;{\mu}mole\;g^{-1}\;min^{-1}$, for ${\beta}-glucosidase$, cellobiohydrolase, ${\beta}-xylosidase$, and N-acetylglucosaminidase, respectively. In general, the activities were highest in the forested swamp followed by the fen and the bog. When the data from three wetlands are combined, the enzyme activities exhibited significant positive correlations with trace gas emission and available carbon. Further, the average activity of 4 enzymes explained about 20-40% of the variations of trace gas emssion and available carbon. The results indicate that enzymes related to the mineralization of organic carbon may play an important role in trace gas flux and DOC dynamics in northern peatlands.

• Composites Research
• /
• v.17 no.6
• /
• pp.1-7
• /
• 2004

The studies of particulate reinforced composites have been conducted for many years. The nanocomposites to be studied vigorously in recent years are one of them. We fabricated and studied multi-walled carbon nanotube(MWNT)/epoxy composites which may be useful as matrix for continuous fiber-reinforced composites. We investigated tensile properties of MWNT/epoxy composites as a function of MWNT concentration, which were prepared by the fabrication method established in this study. Tensile stiffness and strength increased 19% at 0.5 wt% and 12% at 0.2 wt%, respectively. We observed the reaggregation phenomenon of MWNTS during curing, which should be controlled to obtain higher tensile properties.

• Membrane Journal
• /
• v.33 no.6
• /
• pp.390-397
• /
• 2023

Conventional extraction methods for polyhydroxybutyrate (PHB), a sustainable alternative to petroleum-based plastics, cause a decrease in molecular weight and a change in properties. In this work, we developed a method to extract PHB accumulated in microorganisms by physical disruption through filtration using a spiked carbon nanotube (CNT) membrane with functionalized CNT. In addition, filtration of the PHB-containing microbial solution was performed to confirm PHB extraction, which was found to be 4% more efficient than chloroform, the most used extraction method. These results indicate that the spiked CNT membrane has potential in the bioplastics recovery process.

• Annual Conference of KIPS
• /
• 2013.05a
• /
• pp.1055-1057
• /
• 2013

국내외적으로 온실가스 저감을 위한 방안 마련이 필요한 이유로 산업분야에 온실가스 사용량에 대한 산정방법 마련이 시급하다. 물류산업에서도 물류 프로세스상에서 발생하는 온실가스 데이터의 산정을 위해 많은 연구가 진행되고 있지만, 운송에 관련된 분야에 한정적으로 진행되고 있다. 따라서 본 논문에서는 물류프로세스 사이에서 물품의 보관 시 발생하는 전력사용량을 수집하여 온실가스 데이터를 확보하고, 탄소배출량을 산정하는 방안을 제안하고 개발한다.

• Journal of Korean Society of Environmental Engineers
• /
• v.35 no.12
• /
• pp.867-876
• /
• 2013

To promote the carbon emission trading scheme and reduce greenhouse gas (GHG) emission as following 'Korean GHG & Energy Target Management System', GHG emissions should be accurately determined in each industrial sector. For the estimation method of GHG emission from waste landfill, there are several error parameters, therefore we reviewed the estimation method and proposed a revised method. Methane generation from landfill must be calculated by the selected method based on methane recovery rate, 0.75. However, this methodology is not considered about uncertainty factor. So it is desirable that $CH_4$ generation is estimated using first order decay model and methane recovery should use field monitoring data. If not, $CH_4$ recovery could be applied from other study results; 0.60 of operational landfill with gas vent and flaring system, 0.65 of operational site with landfill gas recovery system, 0.90 of closed landfill with final cover. Other parameters such as degradable organic carbon (DOC) and fraction of DOC decompose ($DOC_f$) need to derive the default value from studies to reflect a Korean waste status. Proper application of MCF that is selected by operation and management of landfill requires more precise criteria.

• Journal of Radiation Protection and Research
• /
• v.23 no.3
• /
• pp.175-184
• /
• 1998

In order to calculate dose rates from steam generators to be replaced from Kori unit 1 in 1998, radionuclide inventories inside steam generator were evaluated from smear test results and measured dose rates from S/G tubes withdrawn for the metallographical examination of damaged tubes. Based on the inventories, contact dose rates and dose rates at 1 m from the surface of a steam generator were calculated using the QAD-CG computer code. Contact dose rates ranged from 11.5 mR/hr at the bottom of channel head to 37.7 mR/hr at the middle of shell barrel, and showed no significant difference with dose rates at 1 m from the surface of steam generator. Shielding effects of lead and carbon steel were compared to provide basic shielding data. Lead shield showed excellent shielding effects. Dose rate at 1 m from the middle of S/G shell barrel decreased from 38.6 mR/hr to 15.5 mR/hr with the lead shield of 2 mm thickness. However, carbon steel showed a poor shielding effect even with the thickness of 2.0 cm. This can be explained with the great differences in the attenuation effect and buildup factor between lead and carbon steel for low energy photons.