• Journal of Advanced Marine Engineering and Technology
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• v.38 no.7
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• pp.877-882
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• 2014

The reduction of CO2 emission has been discussed in the Marine Environment Protection committee in the International Maritime Organization as the biggest causes of GHG for the purpose of indexing CO2 amounts released into the atmosphere from ships. Accordingly, various methods including the change in the hull design to improve energy efficiency, the coating development to reduce friction resistances, the additives development for improving thermal efficiency in an engine, the low-speed operation to reduce fuel consumptions, and etc. have been applied. The main engine of a ship is an electronic engine for improving the efficiency of the whole load area. However, marine generator engines still use mechanical drive engines in intake, exhaust, and fuel injection valve drive cams. In addition, most of marine generator engines in ships apply a part-load operation of less then 80% due to an overload protection system. Therefore, marine auxiliary diesel engine set at 100% load is necessary to readjust in order to efficient operation because of part-load operation. The objective of this study is to report the results of the part-load fuel consumption improvement by injection timing readjust to identifying the operational characteristics of a marine generator engine currently operated in a ship.

• Journal of the Korean GEO-environmental Society
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• v.12 no.11
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• pp.51-57
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• 2011

The calcium hydroxide($Ca(OH)_{2}$) which is flowed into the deteriorated tunnel by groundwater is reacted with carbon dioxide($CO_{2}$) and the vehicle's exhaust gas ($SO_{3}$). So its by-products are precipitated at the drainage pipe and these cause the drainage clogging. Most by-products are composed of $CaCO_{3}$ with calcite from a chemical experiment. The purpose of this study is mainly focused on comparison of attachment on each material of drainage pipe (teflon-coated steel pipe, silicon-Oil coated pipe, acrylic pipe and PVC pipe). The test was progressed to disembogue the CaO aqueous solution and tunnel outflow into each of the pipes. The experimental results show that the most produced scale pipe is PVC material and the followings are Acrylic pipe, Silicon-Oil coating pipe and Teflon coating pipe. But the long-term test results showed that teflon-coated steel pipe had a problem with durability because soil which was contained in the tunnel outflow occurred detachment of coating and corrosion of the steel pipe.

• Journal of Preventive Medicine and Public Health
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• v.16 no.1
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• pp.153-156
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• 1983

1950년(年) 이후(以後) 무연탄(無煙炭)으로 만든 연탄(煉炭)을 취사(炊事), 난방용(煖房用)으로 가정(家庭)에서 광범위(廣範圍)하게 사용(使用)하게 되면서 연탄(煉炭)가스내(內)의 일산화탄소(一酸化炭素)로 인(因)한 중독사고(中毒事故)가 빈발(頻發)하여 심각(深刻)한 국민보건(國民保健)의 문제(問題)가 되어왔다. 저자(著者)들의 실태조사(實態調査)(1975년도(年度))에 의(依)하면 서울특별시일원(特別市一圓)에 있어 일산화탄소중독(一酸化炭素中毒)의 년간발생(年間發生)은 인구(人口), 10만당(萬當) 경증(輕症) 260명(名), 혼수상태(昏睡狀態)의 중증중독(重症中毒) 45명(名), 사망(死亡) 1명(名)으로 위험인구(危險人口)를 3,000만명(萬名)으로 하였을 때 전국적(全國的)으로 일산화탄소중독(一酸化炭素中毒)의 추정발생수(推定發生數)는 년간(年間) 경증(輕症) 78만명(萬名), 중증(重症) 13만(萬) 5천명(千名), 사망(死亡) 3,000명(名)으로 그 피해(被害)의 규모(規模)가 100만을 육박(肉薄)하는 가공(可恐)할 수자(數字)를 보여주고 있다. 저자(著者)들은 이러한 심각(深刻)한 국민보건(國民保健)의 문제(問題)를 우선(于先) 실천가능(實踐可能)한 제이차예방(第二次豫防)에 역점(力點)을 두어 고압산소요법(高壓酸素療法)을 보급(普及)할 목적(目的)으로 일인용고압산소장치(一人用高壓酸素裝置)를 개발(開發)하고 1969년(年) 1월(月)에 서울대학교병원(大學校病院)에 고압산소치료실(高壓酸素治療室)을 개설(開設)하여 급성일산화탄소(急性一酸化炭素) 중독환자(中毒患者)에 대(對)한 응급치료(應急治療)를 실시(實施)하여 1978년(年)까지 10년간(年間)의 치료결과(治療結果)를 요약(要約)한바 다음과 같다. 1. 총치료환자수(總治療患者數)는 2,242명(名)이고 회복(回復)된 수(數)는 2,202명(名)으로 98.2%의 회복률(回復率)을 보였다. 2. 계절적(季節的)으로 10월(月)에서 4월(月)까지가 연중최성기(年中最盛期)이나 5월(月)에서 9월(月)까지도 적지않은 환자(患者)의 발생(發生)을 볼 수 있었다. 3. 연령별분포(年齡別分布)를 보면 15세(歲)${\sim}29$세군(歲群)이 전체환자(全體患者)의 반이상(半以上)인 52.7%를 차지하고 있고 $0{\sim}14$세군(歲群)은 인구비(人口比)에 대해 발생(發生)이 훨씬 적은 결과(結果)를 보이고 있다. 4. 도착시간별(到着時間別) 입원율(入院率)은 오전(午前) 10시이후(時以後) 도착군(到着群)서부터는 입원율(入院率)이 급증(急增)하는데 이는 병원도착(病院到着)이 늦일수록 당일회복(當日回復)이 되지못하고 입원가료(入院加療)하게 됨을 나타내주는 결과(結果)라 할 수 있다. 5. 병발증(倂發症)으로는 급성욕창, 폐렴(肺炎) 및 신경학적(神經學的) 이상등(異常等)의 소견(所見)을 많이 볼 수 있었다.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.1
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• pp.42-52
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• 2013

Carbon Capture and Storage (CCS) is a mitigation technology essential in tackling global climate change. In Korea, many research projects are aimed to commercialize CCS business around 2020. Public acceptance can be a key factor to affect the successful proceeds of CCS near future. Therefore this paper provides a concise insight into the application of environmental impact assessment and risk assessment procedures to support the sustainable CCS projects. Futhermore, bottlenecks regarding the environmental impacts assessment and related domestic and foreign legislation are revised. Finally, suggestions to overcome these bottlenecks and recommendations for future research are made in conclusion.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.1
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• pp.61-70
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• 2012

Feasibility of co-digestion was investigated by a series of anaerobic batch experiments using sewage sludge, swine waste, and food waste leachate as substrates. The organic solid wastes were collected from M city, where the daily productions of sewage sludge, swine waste, and food waste leachate were 178 ton/d, 150 ton/d, and 8 ton/d, respectively. Both swine waste and food waste leachate showed superior methane yields, methane productivities, and organic pollutant removal efficiencies compared to sewage sludge. Co-digestion of the total amounts of organic solid wastes would enhance methane production by 5.60 times $(530\;m^{3}\;CH_{4}/d\;{\rightarrow}\;2,968\;m^{3}\;CH_{4}/d)$. However, it also increase the amount of digestate by 1.88 times with 3.79 to 4.92 times higher pollutants (chemical oxygen demands total nitrogen, and total phosphorus) loading rates. Co-digestion of organic solid wastes is a valid strategy to enhance the performance of an anaerobic sludge digester and the energy independence of a wastewater treatment plant. Anyhow,the increment of digestate with higher pollutant loading would need a careful counterplan in the operation of the main stream of the treatment plant.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.443-450
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• 2019

We studied to find the optimal manufacturing conditions of coffee grounds sludge RDF with oil drying method. We expanded the lab scale to pilot scale to compare the efficiency of the oil-drying equipment and The selection of the ratio of coffee grounds and oil, the setting temperature, and the temperature change and water content with time were measured. In order to analyze the characteristics of the research results, characteristics of solid fuels produced(Coffee grounds of oil-dried) by calorimeter, TGA, combustion equipment, and combustion gas measuring instrument were analyzed. As a result, the ratio of oil to coffee grounds was 4: 1, and when the setting temperature was set to $300^{\circ}C$, the water content reached 10wt.% or less within 20 minutes. ln addition, it showed high calorific value of 6,273kcal/kg. However, coffee grounds had a similar composition to wood and showed high luminance and produced a lot of CO in combustion gas. As a result, it is considered to be unsuitable for thermoelectric power plant and camping fuel, but the initial ignition speed is high and the heat generation is high, so it is considered that it can replace the fuels for current use.

• Journal of the Korea Organic Resources Recycling Association
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• v.2 no.1
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• pp.51-64
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• 1994

To compost the food garbage with the dry bean curd and sawdust as the bulking agents, the method of high-speed fermentation by the characteristic microorganisms group was applied. The results of experiments are summarized as follows ; 1. Korean food garbage, which is high in water content, is difficult to compost only by microorganism fermentation without the addition of bulking agents such as dry bean curd cake and sawdust. 2. Weight reduction rates are ranging from 35.6% to 64.5% and varying with the composition of food garbage. The less weight reduction rate is, the longer continuous-fermentation is. And the color of compost is changing sequentially as yellow -> brown -> black. 3. Comparing with the controlled microorganism group, the weight reduction rate and $H_2CO_3$ production rate in the characteristic microorganism group fermentation reactors are higher. And the fermentation rate is satisfactory when the characteristic microorganism group is added. 4. The value of fermented composting as fertilizer diminishes, and the contents of Total Nitrogen, $P_2O_5$, $K_2O$ increase on the condition that the fermentation continues. However, the organic contents and C/N ratio diminish as the fermentation continues. 5. The high-speed fermentation technology demonstractes the possibility of recycling as well as the reduction of composting time provided that it is applied as a pretreatment process for composting.

• The Korean Journal of Food And Nutrition
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• v.30 no.3
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• pp.591-598
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• 2017

To prolong the shelf-life of strawberry, samples were treated with gel packs containing slow-released chlorine dioxide($ClO_2$) gas at 3~7 ppm for 6 days at room temperature. The weight loss and decay ratio as well as changes in pH, color and texture properties of the treated samples were investigated. The weight of the control and $ClO_2$ gas treated samples decreased slightly, but the weight of the control changed faster than those of the $ClO_2$ gas treated samples during the storage period. The decay ratio of control was higher than those of the $ClO_2$ gas treatments since 4 days of storage. The pH and acidity in the control and in the $ClO_2$ gas treated samples were no differences during storage period. The lightness of strawberry decreased during storage, but there was no difference in lightness among the treatments even when storage time was extended. The redness and yellowness of the control showed higher change than those of the $ClO_2$ gas treatments during 6 days. The firmness of the control changed more rapidly than those of the $ClO_2$ gas treatments during 6 days. Especially, the samples treated 3 and 5 ppm $ClO_2$ gas were the least changed. And the scores for appearance, firmness and overall acceptance control and 7 ppm $ClO_2$ gas treatment decreased more rapidly than those of 3 and 5 ppm treatment.

• Korean Journal of Remote Sensing
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• v.36 no.6_1
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• pp.1449-1463
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• 2020

As recent global warming and climate changes become more serious, the importance of CO2 absorption by forests is increasing to cope with the greenhouse gas issues. According to the UN Framework Convention on Climate Change, it is required to calculate national CO2 absorptions at the local level in a more scientific and rigorous manner. This paper presents the gridded expansion of forest flux observations and mapping of daily CO2 absorption by the forests in Korea using numerical weather prediction data and satellite images. To consider the sensitive daily changes of plant photosynthesis, we built a machine learning model to retrieve the daily RACA (reference amount of CO2 absorption) by referring to the climax forest in Gwangneung and adopted the NIFoS (National Institute of Forest Science) lookup table for the CO2 absorption by forest type and age to produce the daily AACA (actual amount of CO2 absorption) raster data with the spatial variation of the forests in Korea. In the experiment for the 1,095 days between Jan 1, 2013 and Dec 31, 2015, our RACA retrieval model showed high accuracy with a correlation coefficient of 0.948. To achieve the tier 3 daily statistics for AACA, long-term and detailed forest surveying should be combined with the model in the future.

• Journal of the Korean Chemical Society
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• v.35 no.2
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• pp.111-118
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• 1991

The kinetic of the gas phase reactions of ozone(0.5 torr) with sulfur dioxide was studied. The SO2 reaction was conducted in the 7∼22 torr range at 90∼155$^{\circ}$C. The reaction rate was faster than the reaction rate of O$_3$ in the presence of CO$_2$ alone. The reaction of O$_3$ with SO$_2$ follows the rate law: -d(O$_3)/dt=k_0(SO_2)(M)(O_3)+2k _1(SO_2)(O_3$). The first term of this rate law arises from a third order molecular reaction predominating in the lower temperature range and gave a rate constant k$_0$ = (9.35 $\pm$ 8.6) ${\times}$ 10$^9$e$^{-(11.05{\pm}2.04)kcal/RT}(M^{-2}s^{-1}$). The second term of the above rate law derived from a second order thermal decomposition reaction which was the major part of the reaction and gave a rate constant k$_0 =(9.35{\pm}8.6){\times}10^9e^{-(11.05{\pm}2.04)kcal/RT}(M^{-2}s^{-1}$). The overall reaction proceeds with kinetics of complex order composed mainly of second order and third order components.