• Environmental Engineering Research
• /
• 제17권1호
• /
• pp.27-34
• /
• 2012

This paper deals with the evaluation of environmental impact of rail and road transport in South Korea. A framework of energy input-output analysis is employed to estimate the total energy consumption and $CO_2$ emission in acquiring and using a life cycle of passenger and freight transport activity. The reliability of $CO_2$ emission based on uncertainty values is assessed by means of a Monte Carlo simulation. The results show that on a passenger-kilometers basis, passenger roads have life cycle emissions about 1.5 times those of rail, while that ratio is ten times greater when the scope of evaluation regards the tailpipe. In the case of freight transport, on a million ton-kilometers basis, the value for road mode is estimated to be about three times compared to those of rail mode. The results also show that the main contribution of $CO_2$ emission for road transport is the operation stage, accounting for 70%; however, the main contribution for rail transport is the construction and supply chain stage, accounting for over 50% emission.

• 생물환경조절학회지
• /
• 제19권4호
• /
• pp.177-183
• /
• 2010

연소식 $CO_2$ 발생기 사용시 사용하는 연료에 따라서 발생되는 $CO_2$ 농도 및 유해가스 농도를 비교 분석하는 것을 목표로 하였다. 사용 연료로는 등유, LPG, LNG를 이용하였다. 연소식 $CO_2$ 발생기는 등유사용 국내제품을 설치한 온실(A), 외국제품을 설치한 온실(B), LPG 사용 국내제품과 외국제품을 설치한 온실 2개소(C와 D) 및 LNG 사용 온실(E)을 선정하였다. 측정은 서울대학교 농생명과학공동기기원(NICEM)의 실내공기질 분석 시스템의 일부 측정시스템을 온실로 이동하여 측정하였다. 연소식 $CO_2$ 발생기 작동 유무에 따른 $CO_2$ 가스 증감은 $NO_x$류의 증감에 정의 상관을 보였으며, 사용 연식에 따른 버너의 내구성 저하에 따른 유해가스 발생량이 증가하였다. CO 농도가 매우 높게 나올 경우에는 발생기 내부에 컨버터를 장착하여 농도를 저감시켜 직물의 생리장해를 예방시킬 필요가 있었다. 전체적으로 $CO_2$ 발생에 따른 유해가스 농도는 최근 설치된 장치에서는 큰 문제가 없었으며 가장 낮은 유해가스 발생량은 국산 LPG 제품을 사용한 D 온실이었다.

• 지적과 국토정보
• /
• 제46권2호
• /
• pp.137-153
• /
• 2016

농산물의 가격은 해마다 변화가 있으며, 가격변화는 수급불균형이 주요한 원인이다. 배추 생산량 예측모델에서 주로 사용되는 자료는 경사 면적 산출이 불가능한 지적성과를 사용하고 있다. 이런 이유로 고랭지 등의 경사지에서 재배되고 있는 밭작물의 수급 예측의 정확도가 떨어져 가격 폭등과 폭락이 반복되고 있는 상황이다. 따라서 이 연구에서는 고랭지 등 경사지를 대상으로 2차원 자료인 지적 성과와 3차원 자료인 라이다데이터를 분석하여 동일지역에서의 데이터 상호간 경작 면적 차이를 비교해 보는 실험을 실시하였다. 이와 함께 경사도 증가에 따른 면적의 변화율을 계량적으로 분석해 낼 수 있는 회귀 모델을 제시하여 지적도와 같은 2차원 평면성과에 의한 경사지 면적 산출의 신뢰도를 향상시킬 수 있는 대안적 방법론을 제시하였다.

• Journal of Microbiology and Biotechnology
• /
• 제26권2호
• /
• pp.233-240
• /
• 2016

FK506, a widely used immunosuppressant, is a 23-membered polyketide macrolide that is produced by several Streptomyces species. FK506 high-yielding strain Streptomyces sp. RM7011 was developed from the discovered Streptomyces sp. KCCM 11116P by random mutagenesis in our previous study. The results of transcript expression analysis showed that the transcription levels of tcsA, B, C, and D were increased in Streptomyces sp. RM7011 by 2.1-, 3.1-, 3.3-, and 4.1-fold, respectively, compared with Streptomyces sp. KCCM 11116P. The overexpression of tcsABCD g enes in Streptomyces sp. RM7011 gave rise to approximately 2.5-fold (238.1 μg/ml) increase in the level of FK506 production compared with that of Streptomyces sp. RM7011. When vinyl pentanoate was added into the culture broth of Streptomyces sp. RM7011, the level of FK506 production was approximately 2.2-fold (207.7 μg/ml) higher than that of the unsupplemented fermentation. Furthermore, supplementing the culture broth of Streptomyces sp. RM7011 expressing tcsABCD genes with vinyl pentanoate resulted in an additional 1.7-fold improvement in the FK506 titer (498.1 μg/ml) compared with that observed under non-supplemented condition. Overall, the level of FK506 production was increased approximately 5.2-fold by engineering the supply of allylmalonyl-CoA in the high-yielding strain Streptomyces sp. RM7011, using a combination of overexpressing tcsABCD genes and adding vinyl pentanoate, as compared with Streptomyces sp. RM7011 (95.3 μg/ml). Moreover, among the three precursors analyzed, pentanoate was the most effective precursor, supporting the highest titer of FK506 in the FK506 high-yielding strain Streptomyces sp. RM7011.

• 자원환경지질
• /
• 제33권6호
• /
• pp.505-517
• /
• 2000

This study was undertaken to provide a drinking water quality on the basis of physicochemical properties. In this study, the 25 samples of supply waters of the Taejon area were sampled twice (February and August in 1999). Hydrochemistry of the supply water belongs to the $Ca^{2＋}$-${HCO_3}^{-1}$ type, whereas the supply water was characterized by the relatively significant enrichment of ${Ca}^{2+}$, ${Na}^{2+}$, ${K}^{2+}$, ${Cl}^{2+}$ ions and heavy metals compared to the original water from the Daecheong lake. Generally, the supply water has a mean values for $10.7^{\circ}C$ of temperature, 6.86 of pH, -12 mV of Eh, 88 ${\mu}S$/cm of EC and 70.379 mg/l of TDS in February, whereas the waters of the same sites in August are a slightly high temperature ($26.1^{\circ}C$), TDS (78.069 mg/l) and extremely high EC (442 ${\mu}S$/cm) value. These values are similar with physicochemical properties of the original lake water depending on the seasonal differences. Results of speciation calculation indicate that potentially toxic ions might exist mainly in the forms of free metal (${Cu}^{2+}$ or ${Zn}^{2+}$) and a small amount of ${CO_3}^{2-}$and ${OH}^{-}$in the supply water. The water seemed to be in equilibrium with kaolinite field of the normal stability diagrams for the natural water. Based on enrichment parameter of the supply water normalized by original lake water composition, the average value of those parameter can be calculated with nearly 1.00, but the those values for Cu＋Zn possible source of decrepit pipe lines are 126.75 in February and 115.63 in August samples. The parameter values varied with sampling sites, however, do not exceed by chemistry of drinking water standard. Solid compounds remained on the membrane filter papers after filtration are adhered to pale yellow or yellowish brown colored dissolved solids and precipitates, which are coated by 0.02 to 0.35 mm thick per 500 ml with colloidal particles of about 1 to 2${\mu}m$ size. The particles are mainly Fe-Cu-Zn compounds and partly detected to Mn and Pb.

• Journal of Microbiology and Biotechnology
• /
• 제8권4호
• /
• pp.409-411
• /
• 1998

The effects of iron and EDTA on the growth of Chlorella sp. KR-1, a highly$CO_2$tolerant fresh water micro alga, have been determined. The algal growth was significantly affected not only by iron concentrations in the medium but by the ratio of iron to EDTA. The linear growth rate and the final cell concentration are increased with the supplementation of EDTA. Enhanced growth of Chlorella sp. KR-1 by the supplementation of EDTA was mainly due to the fact that the supply of iron to the algal culture had been possible for a longer time. When Chlorella sp. KR-1 is cultured in the medium of iron-15H-EDTA, the linear growth rate and the final cell concentration are at their maximum, 0.88 g/l${\cdot}$day and 9.1 g/l, respectively. The results show that Chlorella sp. KR-1 may be used for mass cultivation to fix$CO_2$from stack gases.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
• /
• pp.46-48
• /
• 2006

WASP which is used to plan generation expansion has disadvantages that can't manage environmental factors and regional supply-demand planning. But with the effectuation of the United Nations Framework Convention on Climate Change (UNFCCC) and Kyoto Protocol, it is expected that reducing greenhouse gases affects power system in its long-term generation expansion planning. Therefore national countermeasures is needed. This paper formulates a mathematical model considering CO2 emission constraints and Emission Trading that will be enforced. This model is based on the ORIRES which was made by ESI, Russia and manages generation expansion planning. And this mathematical model is verified by studying a case system.

• 한국광학회:학술대회논문집
• /
• 한국광학회 2000년도 제11회 정기총회 및 00년 동계학술발표회 논문집
• /
• pp.316-317
• /
• 2000

펄스형 $CO_2$레이저는 적외선 영역인 10.6 $mu extrm{m}$ 파장의 매우 안정된 고출력 펄스를 방출시킬 수 있으므로 산업용, 군사용, 의료용, 각종 물리.화학의 기초 연구용 등의 광범위한 응용 분야에서 각광을 받고 있다. 특히 금속의 정밀절단, 심용접에서는 수 십 Hz로부터 수 kHz의 펄스 출력이 필요하다. 펄스방식은 Normal Pulse와 Super Pulse로 크게 나눌 수 있다. Normal Pulse의 경우에는 Pulse의 파고치가 연속파의 파고치와 동일하기 때문에 펄스시의 평균 출력은 연속파의 경우보다 낮다. Super Pulse의 경우에는 Pulse 파고치를 연속파의 파고치보다 훨씬 높게 할 수 있으므로 평균 출력은 낮지만 첨두 출력이 높아서 유리 등 세라믹 재료의 가공에 널리 사용된다$^{(1)}$ (중략)

• 자원환경지질
• /
• 제33권6호
• /
• pp.469-489
• /
• 2000

The hydrogeochemical and isotopic studies on deep groundwater (below a 550 m depth from the ground surface) in the Munkyeong area, Kyeongbuk province were carried out. Two types of deep groundwater (${CO_2}$-rich groundwater and alkali groundwater) occur together in the Munkywong area. ${CO_2}$-rich groundwater (Ca-${HCO_3}$ type) is characterized by low pH (5.8~6.5) and high TDS (up to 2,682 mg/L.), while alkali groundwater (Na-${HCO_3}$ type) shows a high pH (9.1~10.4) and relatively low TDS (72~116 mg/L). ${CO_2}$-rich water may have evolved by ${CO_2}$ added at depth during groundwater circulation. This process leads to the dissolution of surrounding rocks and Ca, Na, Mg, K and ${HCO_3}$ concentrations are eniched. The low $Pco_2$ ($10^{-6.4}$atm) of alkali groundwaters seems to result from the dissolution of silicate minerals without a supply of ${CO_2}$. The ${\delta}^{18}O$ and ${\delta}^D$values and tritium data indicate that two types of deep groundwater were both derived from pre-thermonuclear meteoric water and have evolved through prolonged water-rock interaction. The carbon isotope data show that dissolved carbon in the ${CO_2}$-rich water was possibly derived from deep-seated ${CO_2}$ gas, although further studies are needed. The ${\delta}^{34}S$ values of dissolved sulfate show that sulfate reduction occurred at great depths. The application of various chemical geothermometers on ${CO_2}$-rich groundwater shows that the calculated deep reservoir temperature is about 130~$l75^{\circ}C$. Based on the geological setting, water chemistry and environmental isotope data, each of the two types of deep groundwater represent distinct hydrologic and hydrogeochemical evolution at depth and their movement is controlled by the local fracture system.

• 한국태양에너지학회 논문집
• /
• 제31권5호
• /
• pp.126-133
• /
• 2011

The current world wide interest in environmental issues has moved from energy conservation to $CO_2$emission reduction. Recently, according to the increase in demand for water resources, insufficient potable water circumstance is supposed, unless there are corresponding in crease in water conservation and water recycling. This study has attempted to analyze $CO_2$emission reduction by water saving strategies like installation water saving devices, rain water harvesting and grey water system. To do this, this research investigates applicable water conservative strategies by literature review and calculated total water saving. The results show that (1) firstly, the water usage and $CO_2$ emission could be reduced up to 44%, (2) $CO_2$ emission reduction by water saving devices and rainwater harvesting system is about 47.7%, and (3) water usage and $CO_2$ emission reduction by grey water system is about 66%. In the future, this paper will be utilized for water management from the early design stage to maintenance stage of water glutton building.