• Journal of the Korean Wood Science and Technology
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• v.48 no.5
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• pp.732-744
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• 2020

In this study, a torrefaction of Quercus serrata to manufacture a molded charcoal was performed, investigated material properties, fuel characteristics, and performed a quantitative analysis of hazardous gases which occur during a combustion process. In addition, a molded charcoal in market was selected as a control group, and a comparative analysis was performed. As a result, the higher heating value (HHV) of the torrefied specimen was about 14% higher than that of molded charcoal, and its ash content was about 51 times lower. Moreover, after performing a quantitative assessment of hazardous gases (carbon monoxide, nitrogen oxide, and sulfur dioxide) which were produced when each specimen was combusted for 900 seconds in an enclosed chamber, it was confirmed that the maximum value of generated amount of carbon monoxide on the torrefied specimen was about 50 times lower than that of the existing molded charcoal. Therefore, it was shown that the torrefied specimen produced in this study had a higher heating value than the molded charcoal in the market, and a very low amount of carbon monoxide generated during the combustion process.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.639-647
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• 2022

The use of flames is essential in cutting, bending, and welding steel during a ship's construction process. While acetylene fuel is commonly used in steel cutting and the manufacturing process in shipyards, the use of propane as an alternative fuel has recently been increasing, due to the lower risk of explosion and propane's relatively low calorific value. However, propane fuel has a relatively slow processing speed and high slag generation frequency, thereby resulting in poor quality. Propylene is another alternative fuel, which has an excellent calorific value. It is expected to gain wider use because of its potential to improve the quality, productivity, and efficiency of steel processing. In this study, the combustion characteristics of propane and propylene fuel during steel plate processing were analyzed and compared. The reduction of greenhouse gases and other harmful gases when using propylene flame was experimentally verified by analyzing the gases emitted during the process. Heat distribution and tensile tests were also performed to investigate the effects of heat input, according to processing fuel used, on the mechanical strength of the marine steel. The results showed that when propylene was used, the temperature was more evenly distributed than when propane fuel was used. Moreover, the mechanical tests showed that when using propylene, there was no decrease in tensile strength, but the strain showed a tendency to decrease. Based on the study results, it is recommended that propylene be used in steel processing and the cutting process in actual shipyards in the future. Additionally, more analysis and supplementary research should be conducted on problems that may occur.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.9
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• pp.1577-1582
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• 2016

Now we are facing severe environmental issues such as global warming. Due to these, the concerns about eco-friendly energy have been increased. Kyoto protocol and Copenhagen climate change conference are circumstantial evidence of it. With these trends, the interests for the Electric Vehicles(EVs) which do not emit any harmful gases have gradually been raised. Unfortunately, however, massive connection of EVs to the power system could cause negative impacts such as voltage variations, frequency variations and increase of demand power. To prevent the mentioned issues, KEPCO adopts Time-of-Use(ToU) price for EVs charging. Nevertheless, it is important to verify the propriety of the charging system. In this paper, therefore, we used pre-introduced price elasticity concept to predict possible Demand Response(DR) on charging of EVs. And analyzed possible demand power increase according to various price elasticities. Simulation results show that given ToU based charging system would not enough to control the increase of demand power by EVs on the power system. It is concluded, therefore, additional methods and/or algorithms are required.

• Journal of Microbiology and Biotechnology
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• v.26 no.4
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• pp.717-724
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• 2016

Methane (CH₄) is the most abundant component in natural gas. To reduce its harmful environmental effect as a greenhouse gas, CH₄ can be utilized as a low-cost feed for the synthesis of methanol by methanotrophs. In this study, several methanotrophs were examined for their ability to produce methanol from CH₄; including Methylocella silvestris, Methylocystis bryophila, Methyloferula stellata, and Methylomonas methanica. Among these methanotrophs, M. bryophila exhibited the highest methanol production. The optimum process parameters aided in significant enhancement of methanol production up to 4.63 mM. Maximum methanol production was observed at pH 6.8, 30℃, 175 rpm, 100 mM phosphate buffer, 50 mM MgCl₂ as a methanol dehydrogenase inhibitor, 50% CH₄ concentration, 24 h of incubation, and 9 mg of dry cell mass ml^-1 inoculum load, respectively. Optimization of the process parameters, screening of methanol dehydrogenase inhibitors, and supplementation with formate resulted in significant improvements in methanol production using M. bryophila. This report suggests, for the first time, the potential of using M. bryophila for industrial methanol production from CH₄.

• Journal of Ocean Engineering and Technology
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• v.34 no.1
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• pp.46-54
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• 2020

Oil spill accidents at sea result in a wide range of damages, including the destruction of ocean environments and ecosystems, as well as human illnesses by the generation of harmful gases caused by phase changes in crude oil. When an oil spill occurs, an immediate initial action should be performed to minimize the potential damage. Existing studies have attempted to identify crude oil spillage by calculating the crude oil spill range using synthetic aperture radar (SAR) satellite images. However, SAR cannot capture rapidly evolving events because of its low acquisition frequency. Herein, an algorithm for estimating an oil spill area from an image obtained using a digital camera is proposed. Noise that may occur in the image when it is captured is first eliminated by preprocessing, and then the image is analyzed. After analyzing the characteristics of the digital image, a strategy to binarize an image using the color, saturation, or lightness contained in it is adopted. It is found that the oil spill area can be readily estimated from a digital image, allowing for a faster analysis than any conventional method. The usefulness of the oil spill area measurement was confirmed by applying the developed algorithm to various oil spill images.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.75-82
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• 2018

Efforts to reduce damages from micro dust and harmful gases in life have been led by national or local governments, and information on air quality has been provided along with real-time weather forecast through TV and internet. It is not enough to provide information on the individual indoor space consumed. So in this paper, we propose a IoT-based Real-Time Air Quality Sensing Board Corresponding Fine Particle for Air Quality Management in Buildings. Proposed board is easy to install and can be placed in the right place. In the proposed board, the air quality (level of pollution level) in the indoor space (inside the building) is easy and it is possible to recognize the changed indoor air pollution situation and provide countermeasures. According to the advantages of proposed system, it is possible to provide useful information by linking information about the overall indoor space where at least one representative point is located. In this paper, we compare the performance of the proposed board with the existing air quality measurement equipment.

• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.465-470
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• 2010

Korea government declared that "low carbon, green growth" through green technologies and clean energy to be the new national vision for the next 60 years(President's Liberation Day speech on Aug. 15, 2008). And succeeding "Green New Deal" plan involves nine core projects including energy saving, recycling, clean energy development. It is because hydrogen fuel cell vehicles, using electricity from chemical reaction of hydrogen and oxygen, let out water which is a by-product of such chemical reaction instead of emitting harmful particulate and gases such as NOX, SOX and CO2 that hydrogen fuel cell vehicles and its technology are drawing public attention as one of the sensible solutions in accomplishing "low carbon, green growth" agenda. Nevertheless There are many chances that let the people have a practical experience of hydrogen fuel cell vehicles. Sometimes new products, including hydrogen fuel cell vehicles, made by advanced technology can not penetrate through the market when it faces public skepticism that is stimulated from lack of knowledge and experience. That is the reason why not only cost benefit analyses and scientific risk assessments but also public acceptance studies toward hydrogen fuel cell vehicles have to be performed [Schulte, 2004]. This research address a need for comprehensive study on factors influencing public acceptance of hydrogen fuel cell car, specifically focusing on impacts of personal experience related to governmental science and technology policy toward public acceptance.

• Journal of Yeungnam Medical Science
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• v.21 no.2
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• pp.133-142
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• 2004

Chronic obstructive pulmonary disease(COPD) is characterized by a not entirely reversible limitation in the airflow. An airflow limitation is progressive and associated with an abnormal inflammatory response of the lung to gases and harmful particles. In COPD, the weight loss is commonly observed and there is a negative impact on the respiratory as well as skeletal muscle function. The pathophysiological mechanisms that result in weight loss in COPD are not fully understood. However, the mechanisms of weight loss in COPD may be the result of an increased energy expenditure unbalanced by an adequate dietary intake. The commonly occurring weight loss and muscle wasting in COPD patients adversely affect the respiratory and peripheral muscle function, the exercise capacity, the health status, and even the survival rates. Therefore, it is very valuable to include management strategies that the increase energy balance in order to increase the weight and fat free mass. A Better understanding of the molecular and cellular pathological mechanisms of COPD can improve the many new directions for both the basic and clinical investigations. The Nutritional supply is an important components of a multidisciplinary pulmonary rehabilitation program. Future studies combining an exercise program, the role of anabolic steroids, nutritional individualization, a more targeted nutritional therapy, and the development of new drugs including anti-cytokines is needed for the effective management of COPD.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.1
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• pp.20-31
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• 2008

A respirator is useful to protect a worker from the harmful gases and vapors in the workplace, and the evaluation of respirator cartridge service life is important for the worker's health and safety. The performance of cartridge is effected by several factors such as concentration of gas and vapor, humidity, temperature, adsorbents and cartridge packing density. Adsorption model was applied to both sampling tube and respirator cartridge to predict the service life for organic vapors. The variables of the adsorption model were measured from the experiment with the sampling tube, and it was used to predict the service life of respirator cartridge. In the experiment, we used carbon tetrachloride as a organic vapor and activated carbon take out respirator cartridge as activated carbon. As a result, it was possible to predict the service life of respirator cartridge and predicted service life was quite correct. Breakthrough time decreased with increase of CCl4 concentration. In case of sampling tube, adsorbed amount of CCl4 was larger than respirator cartridge due to linear velocity. Also, rate constant of sampling tube was larger than respirator cartridge, because of, effect of flow rate, packing density. In the prediction of service life of respirator cartridge by using sampling tube, the time required for 50% contaminant breakthrough(${\tau}$) is more effective than the rate constant(k').

• Advances in concrete construction
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• v.9 no.4
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• pp.345-354
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• 2020

Cement is the most significant component in concrete. Large scale manufacturing of cement consumes more energy and release harmful products (Carbon dioxide) into the atmosphere that adversely affect the environment and depletes the natural resources. A lot of research is going on in globally concentrating on the recycling and reuse of waste materials from many industries. A major share of research is focused on finding cementitious materials alternatives to ordinary Portland cement. Many industrial waste by-products such as quartz powder, metakaolin, ground granulated blast furnace slag, silica fume, and fly ash etc. are under investigations for replacement of cement in concrete to minimize greenhouse gases and improve the sustainable construction. In current research, the effects of a new generation, ultra-fine material i.e., alccofine which is obtained from ground granulated blast furnace slag are studied as partial replacement by 25% and with varying amounts of sulfonated naphthalene formaldehyde (i.e., 0.3%, 0.35% and 0.40%) on mechanical, water absorption, thermal and microstructural properties of concrete. The results showed moderate improvement in all concrete properties. Addition of SNF with combination of alccofine showed a significant enhancement in fresh, hardened properties and water absorption test as well as thermal and microstructural properties of concrete.