• 상하수도학회지
• /
• 제12권3호
• /
• pp.65-74
• /
• 1998

Life cycle assessment (LCA) on two different sludge treatment systems, on-site treatment and pipe-collected intensive treatment was performed to estimate the environmental impact in the aspect of global warming effect. As a main parameter of the estimation, $CO_2$ was chosen and quantified through the whole life cycle of the treatment systems including construction, operation and dismantlement. In this study, the changes of $CO_2$ production unit (CPU) by up-scaling n currently used sludge treatment processes were also calculated. As the result, a larger amount of $CO_2$ was exhausted from the construction step of intensive treatment system than that of on-site treatment system, because an additional pipe-collection system was needed in intensive treatment system. However, the total amount of $CO_2$ exhausted from whole life cycle including not only construction and dismantlement but also 15 year-operation and maintenance was reduced by appling intensive treatment.

• Journal of the Korean Wood Science and Technology
• /
• 제35권1호
• /
• pp.17-26
• /
• 2007

본 연구에서는 수증기댐처리 또는 횡단면 코팅처리 등이 오동나무 장고용 초갈이재의 송풍오븐건조 특성에 미치는 영향을 구명코저하였다. 건조개시 직후의 중량감소량은 무처리(C-NC treatment), 엔드코팅처리(C-CO treatment), 수증기댐처리(V-NC treatment), 수증기댐-엔드코팅처리(V-CO treatment)재의 순으로 크게 나타났다. V-CO처리재는 V-NC처리재와 비교하여 전(全)건조기간에 걸쳐 더 완만한 온도경사를 보였으며 내층과 외층간에 온도경사가 거의 존재하지 않았다. C-CO처리재의 경우 C-NC처리재와 비교하여 건조중기까지는 외층과 내층의 수증기압 모두가, 그리고 건조중기 이후에는 내층의 수증기압이 더 높게 나타났다. V-CO처리재의 경우 건조초기에는 V-NC처리재와 유사한 분포를 보였으나, 건조초기 이후 통공, 외층, 내층의 순으로 절대수증기압이 큰 분포를 보이면서 V-NC처리재와는 전혀 다른 분포모형이 관찰되었다. 재면할렬과 윤할은 모든 처리재에서 전혀 발생하지 않았으나 엔드코팅을 실시하지 않은 C-NC와 V-NC에서는 횡단면할렬이 심하게 발생하였다.

• 한국수산과학회지
• /
• 제51권1호
• /
• pp.54-63
• /
• 2018

We investigated the effect of $CO_2$ exposure on the reproductive process of chameleon goby Tridentiger trigonocephalus. Rearing aquaria were exposed for 90 days to $CO_2$ gas through diffuser connected with pH controller maintaining at pH 7.2 ($156.31{\pm}7.90ppm$) in low treatment, and at pH 6.5 ($274.17{\pm}6.51ppm$) in high treatment. $CO_2$ treatment had no significant effects on survival rates although the value was decreased compared to the controls. In female fish, $CO_2$ treatment had no significant effects on gonadosomatic index (GSI), hepatosomatic index (HSI) and condition factor (CF). However, high $CO_2$ treatment decreased HSI and CF in males significantly compared to the controls (P<0.05). The spawning occurrence was 6 times in the low level $CO_2$ treatment, and 4 times in the high level $CO_2$ treatment although only once in the controls. For the histological observations, there was no significant difference in $CO_2$ treatments. However, in male fish, $CO_2$ treatment delayed the formation of sperm from spermatid compared to controls. These results suggest $CO_2$ may disrupt reproductive process by delaying gametogenesis in chameleon goby and it was more sensitive in males.

• Korean Chemical Engineering Research
• /
• 제58권1호
• /
• pp.150-162
• /
• 2020

The proprietary post-combustion CO₂ solvent (KoSol) developed by the Korea Electric Power Research Institute (KEPRI) was applied at the Shanghai Shidongkou CO₂ Capture Pilot Plant (China Huaneng CERI, capacity: 120,000 ton CO₂/yr) of the China Huaneng Group (CHNG) for performance evaluation. The key results of the pilot test and data on the South Korean/Chinese electric power market were used to calculate the predicted cost of CO₂ avoided upon deployment of CO₂ capture technology in commercial-scale coal-fired power plants. Sensitivity analysis was performed for the key factors. It is estimated that, in the case of South Korea, the calculated cost of CO₂ avoided for an 960 MW ultra-supercritical (USC) coal-fired power plant is approximately 35~44 USD/tCO₂ (excluding CO₂ transportation and storage costs). Conversely, applying the same technology to a 1,000 MW USC coal-fired power plant in Shanghai, China, results in a slightly lower cost (32~42 USD/tCO₂). This study confirms the importance of international cooperation that takes into consideration the geographical locations and the performance of CO₂ capture technology for the involved countries in the process of advancing the economic efficiency of large-scale CCS technology aimed to reduce greenhouse gases

• 약학회지
• /
• 제24권2호
• /
• pp.79-86
• /
• 1980

CO-intoxication is a serious problem in public health since the coal briquette has been used as one of fuels from 1950's. It has been discussed that the treatment with acetic acid vapor may be effective for CO-intoxication. This study was undertaken to investigate the action of acetic acid therapy, comparing with the spontaneous air treatment The acetic acid vapor was introduced to the blood combined with CO (in vivo and in vitro). The dissociation of COHb, the production of COHb, the levels of Hb and adrenaline and nor-adrenaline were measured. The effect of acetic acid vapor on dissociation of COHb was about 7-9% more effective than the spontaneous air treatment. The acetic acid vapor treatment for the dissociation of COHb was similar effect to the spontaneous air treatment. In an experiment of the combining CO gas with blood, the acetic acid vapor treatment was less effective in the production of COHb than that of spontaneous air treatment. Treatment with the acetic acid vapor to rabbit intoxicated with CO gas induced a little amount of Hb in blood comparing with the spontaneous air treatment. But, it is not a significant increment statistically. By the acetic acid vapor treatment after CO gas intoxication the adrenaline was increased and noradrenaline was decreased. With these results, it is assumed that the effect of acetic acid therapy on CO-gas intoxication would be caused by inductions of Hb and adrenaline and to be reduction of nor-adrenaline.

• Journal of Ecology and Environment
• /
• 제33권3호
• /
• pp.195-204
• /
• 2010

In the study, the effects of elevated $CO_2$ and temperature on the photosynthetic characteristics, chlorophyll content, nitrogen content, carbon content, and C/N ratio of Phytolacca insularis and Phytolacca americana were examined under control (ambient $CO_2+$ ambient temperature) and treatment (elevated $CO_2+$ elevated temperature) for 2 years (2008 and 2009). The photosynthetic rate, transpiration rate and water use efficiency of two plant species were higher under the treatment than the under the control. The stomatal conductance of P. insularis was higher under the control, but that of P. americana was not significantly affected by $CO_2$ and temperature under the treatment. The chlorophyll contents of two species were decreased about 72.5% and 20%, respectively, by elevated $CO_2$ and temperature. The nitrogen contents of two species were not significantly altered by increase in $CO_2$ and temperature. The carbon contents of the two species were higher under the treatment than under the control. The C/N ratio of P. insularis was higher under the treatment but that of P. americana was not significantly affected by $CO_2$ and temperature. These results demonstrated that the physiological responses of P. insularis native plants might be more sensitively influenced by a $CO_2$-mediated global warming situation than those of the P. americana invasive plants.

• 농업과학연구
• /
• 제41권1호
• /
• pp.9-16
• /
• 2014

This experiment was conducted to examine the effects of a short-term treatment of high pressure $CO_2$ on shelf-life of strawberry fruit. A short-term treatment (12 hr) of 100% $CO_2$ resulted in the increase of fruit firmness up to 71.9% compared to that at harvest. The firmness of $CO_2$ treated fruit remained a significantly higher than that of control (air) up to 15 days. The alteration of pectic polymers was observed by $CO_2$ treatment such as an increase of EDTA soluble pectins and decrease of water soluble ones. The $CO_2$ treatment resulted in the increase of total amount of wall bound calcium. Pectate lyase activity, an important agent of strawberry fruit softening, was also significantly reduced by $CO_2$ treatment. Contents of soluble solids and acids of $CO_2$ treated fruit were higher than those of control fruit. Short-term treatment of high pressure $CO_2$ affected shelf-life through firmness increase whereas the visual quality and decay incidence of strawberry fruit were not affected.

• 상하수도학회지
• /
• 제11권2호
• /
• pp.50-64
• /
• 1997

Life cycle assessment (LCA) on total sewage sludge treatment system from thickening to incineration and melting was performed for estimating global environmental impact as $CO_2$. In general, the life cycles of actual treatment facilities consist of construction, operation and dismantlement. In this study, the amount of $CO_2$ produced from both whole and each life cycle step of currently used unit sludge treatment processes were calculated by inventory analysis. In addition, in the all processes investigated in this study, individual $CO_2$ production unit (CPU), i.e. total produced $CO_2$ by treating a unit weight of sludge was also calculated. By using the CPU matrix of the unit processes, it was possible to simulate the $CO_2$ production for any type of complex-system as well as to trace a dominant cause of $CO_2$ production in each process. Four selected alternatives examined here, each involve the same disposal way but differ substantially in the $CO_2$ exhaust.

• 열처리공학회지
• /
• 제23권3호
• /
• pp.137-141
• /
• 2010

The Co-Cr alloys have clinical histories in dental and orthopaedic implants, and recently in cardiovascular stent applications because the alloys exhibit a high elastic modulus and radiopacity. In order to improve mechanical property of the Co-Cr alloys, electropolishing is employed as the final process. Electropolishing, an anodic dissolution process in the transpassive state, is sensitively affected by process conditions such as current density, machining time, electrode gap. In this study, the effect of heat treatment conditions on surface roughness and inclusion analysis is investigated in Co-Cr alloy (L605). The most smooth surface of Co-Cr alloy is obtained when electropolishing is performed at 15-20 V for 15-30 sec with a electrode gap of 3.5 mm.

• 한국세라믹학회지
• /
• 제34권7호
• /
• pp.747-757
• /
• 1997

ZSM-5 zeolite composite membranes have been synthesized from a silica sol solution containing TPABr as an organic template by the dip-coating and the pressurized-coating hydrothermal treatment techniques. The CO2 separation efficiency of synthesized composite membranes was also investigated. The permeation mechanism of CO2 through ZSM-5 membranses was the surface diffusion, and that of N2, O2, and He gases was Knudsen diffusion or activated diffusion depending on the synthetic method of membranes and the measurement temperature. The CO2/N2 separation factor of the membrane prepared by the dip-coating hydrothermal treatment was 2.5 at about 12$0^{\circ}C$, while the ZSM-5 composite membrane synthesized by the pressurized-coating hydrothermal treatment technique showed the CO2/N2 separation factor of 9.0 at room temperature higher than that ever reported in the literature.