• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.3
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• pp.375-388
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• 2017

In order to solve the traffic congest and environmental issues, small-cross section tunnel for small car only is increasing, but there is not standard for installation of disaster prevention facility. In this study, in order to investigate the behavioral characteristics of thermal environment and smoke in a small cross section tunnels with a large port exhaust ventilation system, the A86, the U-Smartway and the Seobu moterawy tunnel, Temperature and CO concentration in case of fire according to cross sectional area, heat release rate and exhaust air flow rate were analyzed by numerical analysis and the results were as follows. As the cross-sectional area of the tunnel decreases, the temperature of the fire zone increases and the rate of temperature rise is not significantly affected by heat release rate. However, there is a difference depending on the change of the exhaust air flow rate. In the case of applying the exhaust air flow rate $Q_3+2.5Ar$ of the large port exhaust ventilation system, the temperature of the fire zone was 7.1 times for A86 ($Ar=25.3m^2$) and 5.4 time for U-smartway ($Ar=37.32m^2$) by Seobu moterway tunnel ($Ar=46.67m^2$). The CO concentration of fire zone also showed the same tendency. The A86 tunnels were 10.7 times and the U-Smartways were 9.5 times more than the Seobu moterway. Therefore, in the case of a small section tunnel, the thermal environment and noxious gas concentration due to the reduction of the cross-sectional area are expected to increase significantly more than the cross-sectional reduction rate.

• Journal of the Korean Applied Science and Technology
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• v.34 no.2
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• pp.289-295
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• 2017

The International Maritime Organization (IMO) in accordance with the regulations with respect to the combustion gases, such as NOx, SOx generated by the marine engine. The combustion gases must be equipped with a device to reduce emissions from all ships passing through the Baltic SECAs. In Korea, the International Maritime Organization (IMO) and the development of a device for NOx, SOx reduction. Scrubber is used in the ammonia water and the Urea solution in the waste water. The waste water containing ammonium nitrate and ammonium sulfate, react of the NOx and SOx gas. In this study, the recovery of by-product, which contains the waste water was used as an organic solvent extraction method of salting out. Ammonium nitrate and ammonium sulfate, the recovery process. A qualitative analysis of the collected by-product FT-IR analysis. Through the elemental analysis and SEM-EDS, characteristic evaluation was performed with an impurity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6581-6589
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• 2013

This study reset the Examination Criteria for Energy Use Plan by the project sector so that the Consultation about Energy Use Plan would play an effective role in reaching the National Energy Policy Issues, and to prevent complaints from the superintendent of the project & agent engaged in the project. To achieve this aim, consultation case analysis was carried out from 2001 to 2010 and the National Energy Master Plan was reviewed. The predicted effect of energy savings calculated by reset Examination Criteria on the $1^{st}$ energy demand target at 2030 was 2.5%, the effect of new and renewable energy utilization on a new and renewable energy supply target at 2030 was 3% and the rate of $CO_2$ reduction to greenhouse gas emission BAU at 2020 was 1.1%.

• Journal of the Korean Electrochemical Society
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• v.8 no.1
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• pp.24-31
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• 2005

Ion shower doping with a main ion source of $P_2H_x$ using a source gas mixture of $PH_3/H_2$ was conducted on excimer-laser-annealed (ELA) poly-Si.The crystallinity of the as-implanted samples was measured using a UV-transmittance. The measured value using UV-transmittance was found to correlate well with the one measured using Raman Spectroscopy. The sheet resistance decreases as the acceleration voltage increases from 1kV to 15kV at the moderate doping conditions. It, however, increases as the acceleration voltage increases under the severe doping conditions. The reduction in carrier concentration due to electron trapping at uncured damage after activation annealing seems to be responsible for the rise in sheet resistance. Three different annealing methods were investigated in terms of dopant-activation and damage-recovery, such as furnace annealing, excimer laser annealing, and rapid thermal annealing, respectively.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.229-235
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• 2004

A study was conducted to examine the effect of dietary supplementation of multiple probiotics (EM) on growth performance, blood cholesterol, intestinal micro flora, and fecal gas emission in broiler chicks. A total of 450 one day old male broiler chicks (Ross $\times$ Ross) were divided into six treatments with five replications in each treatment for five weeks. Treatments were factorially designed with two levels of diet containing probiotics (DW; 0, $0.2\%$) and three levels of drinking water containing probiotics (DW; 0, 0.01, $0.1\%$). Basal diets contained $21.5\%$ CP and 3,100 kcal/kg ME for starting and $19\%$ CP and 3,100 kcal/kg ME for finishing period. Weight gain, feed intake, and feed conversions of birds fed with probiotics were not significantly different between Ds. Total cholesterol and triglyceride levels were significantly lower (P<0.05) in birds fed with DW $0.01\%$ or $0.1\%$ compared with no probiotics group, but there was no significant difference between D treatments. The number of E. coli, Salmonella and Lactobacillus in the ileum and cecum of the birds fed multiple probiotics were not significantly different from those of no probiotic groups. There were no significant differences in the $CO_2$ gas emissions of fecal between birds fed with Ds or among birds fed with DW. However, $NH_3$ gas emissions of DW $0.1\%$ were significantly lower (P<0.05) than DW $0\%$. In the results of this study, supplementation of probiotics tended to decrease the serum cholesterol and triglyceride compared to those of control groups and reduction of fecal $NH_3$ gas emission.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.2
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• pp.87-91
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• 2015

As negative effects of climate change have been visualized and its direct damages to economy have been realized, the global efforts to respond to climate change by reducing greenhouse gas emission were accelerated. Korea's Carbon Footprint Labeling gets a lot of attention as one of the effective methods to contribute to national GHG reduction goal, and for enterprises to show customers how much effort the company put into global warming prevention. Consumers' interest on low-carbon products has been increasing. This study uses Life Cycle Assessment method to calculate the amount of carbon emission of dishwashing detergent, LG Household & Healthcare, which reduced carbon emissions by using raw materials that has relatively lower environment load. Life Cycle Assessment Method is based on guidelines of Carbon Footprint Labeling, Ministry of Environment, and pre-manufacturing, manufacturing, and disposal phase are included while use phase of the product is excluded from assessment. In order to understand the effects of eco-design on carbon emissions, the dishwashing detergent's carbon emissions are compared before and after the change of main raw materials. The result shows the improvement from $0.47kgCO_2eq/kg$ to $0.38kgCO_2eq/kg$ per product, and this means the main raw materials' carbon emissions could be reduced by around 9.4%, which is equivalent to 916tons of GHG emissions per year.

• Journal of Climate Change Research
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• v.2 no.2
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• pp.93-106
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• 2011

Republic of Korea officially announced its mid term reduction target which reduce about 30% of BAU GHG emission by 2020 in the 15th meeting of UNFCCC(COP 15) held in Copenhagen, Denmark 2009. To achieve this goal, it is necessary to understand the serious of climate change and take part in GHG reduction not only industry but also the nation. However, such positive participation in green life which may cause inconvenient of the life of the people. It should be accomplished with providing reliable information. This study suggests the scientific potentialities of GHG emission by guideline on low carbon life and green life to form and change a lifestyle suitable for coping with climate change. And also, this study quantitate the GHG reduction which may reduce demand for air conditioning by cool biz and warm biz. In Korea, this campaign has become known as 'CoolMaebsi' by Ministry of Environmental of Korea. 'CoolMaebsi' is a compound word of 'Cool' which means feel refreshed, and 'Maebsi' is a Korean word which means attire. Though this campaign is effective and significant to reduce the GHG emission yet there were no study on quantitative analysis. Therefore this study calculated reduced energy consumption and potential GHG emission by measuring variation of skin temperature. As the result, wearing warm biz and cool biz have an effect of reducing not only the energy consumption but also GHG emission. To achieve the low carbon society, it is necessary to improve the energy saving system and introduce the policy which guide to change a life style.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.2
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• pp.45-53
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• 2009

Today, reduction of $CO_2$ exhaustion gas for global-warming prevention becomes important issues in all industrial fields. Hydraulic systems have been widely used in industrial applications due to high power density and so on. However hydraulic pump is always being operated by engine or electric motor in the conventional hydraulic system. Therefore most of the conventional hydraulic system is not efficient system. Recently, an electro-hydraulic hybrid system, which combines electric and hydraulic technology in a compact unit, can be adapted to a wide variety of force, speed and torque requirements. In the electro-hydraulic hybrid system, hydraulic pump is operated by electric motor only when hydraulic power is needed. Therefore the electro-hydraulic system can reduce the energy consumption drastically when compared to the conventional hydraulic systems. This paper presents a new kind of hydraulic load simulator which is composed of electro-hydraulic hybrid system. Disturbances in the real working condition make the control performance decrease or go bad. QFT controller is designed to eliminate or reduce the disturbance and improve the control performance of the electro-hydraulic load simulator. Experimental results show that the proposed controller is verified to apply for electro-hydraulic hybrid system with varied external disturbances.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.1
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• pp.30-35
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• 2016

Rice cultivation in paddy field affects the global balance of methane ($CH_4$) as a key greenhouse gas. To evaluate a potential use of by-product gypsum fertilizer (BGF) in reducing $CH_4$ emission from paddy soil, $CH_4$ fluxes from a paddy soil applied with BGF different levels (0, 2, 4 and $8Mg\;ha^{-1}$) were investigated by closed-chamber method during rice cultivation period. $CH_4$ flux significantly decreased (p<0.05) with increasing level of BGF application. $8Mg\;ha^{-1}$ of BGF addition in soil reduced $CH_4$ flux by 60.6% compared to control. Decreased soil redox potential (Eh) resulted in increasing $CH_4$ emission through a $CO_2$ reduction reaction. The concentrations of dissolved calcium (Ca) and sulfate ion (${SO_4}^{2-}$) in soil pore water were significantly increased as the application rate of BGF increased and showed negatively correlations with $CH_4$ flux. Decreased $CH_4$ flux with BGF application implied that ${SO_4}^{2-}$ ion led to decreases in electron availability for methanogen and precipitation reaction of Ca ion with inorganic carbon including carbonate and bicarbonate as a source of $CH_4$ formation under anoxic condition. BGF application also increased rice grain yield by 16% at $8Mg\;ha^{-1}$ of BGF addition. Therefore, our results suggest that BGF application can be a good soil management practice to reduce $CH_4$ emission from paddy soil and to increase rice yield.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.3
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• pp.376-380
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• 2006

An experiment was conducted to study the effect of temperature and pH on in vitro nutrient degradability, volatile fatty acid profile and methane production. The fermenter used was the semi-continuous system, known as the rumen simulation technique (RUSITEC). Sixteen cylinders were used at one time with a volume of 800 ml, the dilution rate was set at 3.5%/hour, the infused buffer being McDougall's artificial saliva. Basal diet (9.6 g DM) used in RUSITEC consisted of (DM) 6.40 g Timothy hay, 1.86 g crushed corn and 1.34 g soybean meal. The food for the fermentation vessel was provided in nylon bags, which were gently agitated in the liquid phase. The experiment lasted for 17 d with all the samples taken during the last 5 d. Treatments were allocated at random to four vessels each and were (1) two temperature levels of $39^{\circ}C$ and $41^{\circ}C$ (2) two pH levels of 6.0 and 7.0. The total diet contained ($g\;kg^{-1}$ DM) 957 OM, 115 CP and $167MJ\;kg^{-1}$ (DM) GE. Although increase in temperature from $39^{\circ}C$ to $41^{\circ}C$ reduced degradation of major nutrients in vitro, it was non-significant. Interaction effect of temperature with pH also reflected a similar trend. However, pH showed a significant (p<0.05) negative effect on the degradability of all the nutrients in vitro. Altering the in vitro pH from 7 to 6 caused marked reduction in DMD from 60.2 to 41.8, CPD from 76.3 to 55.3 and GED from 55.3 to 35.1, respectively. Low pH (6) depressed total VFA production (61.9 vs. 34.9 mM) as well as acetate to propionate ratio in vitro (from 2.0 to 1.5) when compared to pH 7. Compared to pH 7, total gas production decreased from 1,841 ml to 1,148 ml at pH 6, $CO_2$ and $CH_4$ production also reduced from 639 to 260 ml and 138 to 45 ml, respectively. This study supported the premise that pH is one of the principal factors affecting the microbial production of volatile fatty acids and gas. Regulating the ruminal pH to increase bacterial activity may be one of the methods to optimize VFA production, reduce methane and, possibly, improve animal performance.