• Journal of the Korean Wood Science and Technology
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• v.41 no.4
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• pp.293-301
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• 2013

This study discusses the feasibility of coffee bean residue as a raw material of medium-density fiberboard (MDF). In this relation, the effect of coffee bean residue known as an absorbent material on the physical and mechanical properties of MDF manufactured at its different addition level. Coffee bean residue which is a by-product of coffee mill and large amount of waste left over after processing for instant coffee was added at the level of 3, 6, and 9% on dry basis and urea formaldehyde resin was used as the adhesive. The MDF made with mixture of wood fiber and coffee bean residue was tested for physical and mechanical properties as well as formaldehyde emission. The bending strength and internal bonding strength of the MDF made with mixture of wood fiber-coffee bean residue were higher than that of the KS standard in randomized mat structure type, but not in layered mat structure type. Also, the physical properties of MDF made with mixture of wood fiber-coffee bean residue showed a considerable improvement in thickness swelling over the commercial MDF. More importantly, the formaldehyde emission rate of MDF made with mixture of wood fiber-coffee bean residue met the KS standard and was close to that of commercial MDF. These results showed the feasibility of coffee bean residue as a raw material for the production of environmentally-friendly MDF. Additional works on adhesive-coffee bean compatibility, improvement of moisture absorption effect and reduction the formaldehyde emission rate by carbonization of coffee bean residue may be required.

• Journal of Environmental Impact Assessment
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• v.16 no.6
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• pp.467-483
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• 2007

Environmental Impact Assessment (EIA) is a kind of planning technique to seek ways to minimize environmental impact, a scheme to encourage sustainable development. With the launch of the Ministry of Environment in 1980, the EIA was introduced in Korea. Its full operation was initially driven by regulations on documenting EIA reports in 1981, which was piloted as a decision-making scheme where final decision were made at the development department after considering opinions suggested by the Ministry of Environment. At that time, dominance of the economic logic overwhelmed environ-friendly opinions, but thanks to the fourth revision of the Environmental Conservation Law in 1986, private projects came to be included on the EIA list. This was a turning point for the EIA to become a regulatory system. Local governments are also conducting the EIA regardless of the national-level EIA. In order to prevent and resolve increasingly severe environmental problems in Seoul in advance due to various construction projects, the Seoul Metropolitan Government, for the first time as a local government in Korea, legislated city decrees to introduce the EIA which has been underway from September 1, 2002. In particular, the Seoul government, unlike the Ministry of Environment, has included construction works on the list of evaluation projects, adopting the scoping and screen procedure scheme. In addition, complementing operational setbacks, the city government has revised and implemented decrees and enforcement laws on the Impact Assessment on Environment, Transportation and Disasters by shortening the consultation period, eliminating the submission of reports on construction, and expanding the waiver requirements in consultation over the reports. Therefore, development measures for the EIA scheme of the Seoul Metropolitan Government will be the target of the research. To that end, the up-to-date data of the Ministry of Environment, the Seoul government and local governments was collected, and latest materials from the EU, previous research and the Internet were gathered for analyses. By doing so, the flow of the EIA was reviewed, and the EIA schemes of local governments under the national EIA were analyzed. Furthermore, based on the Seoul government's recent data on the EIA based on the decrees, the background and legislation of the Seoul government's EIA were analyzed along with the developments for the environmental organizations. Setbacks were derived from the implementation period, evaluation procedures, consultation period and details of the EIA, and corresponding development measures were proposed.

• The Korean Journal of Pesticide Science
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• v.19 no.4
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• pp.411-417
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• 2015

This study is conduced to investigate control efficacy of mixture of plant extracts which has been reported to control pest and Bacillus thuringiensis or alone. Control efficacy of 0.025% matrine or mixture of 0.016% matrine and BT ($5{\times}10^4cfu$) against $3^{rd}$ instar larvae of beet armyworm were best as 98.7% and 93.3%. Treatment of mixture of 0.01% matrine and BT ($5{\times}10^4cfu$) showed the mortality of 69.3%. In the case of neem, when the mixture of 0.1% neem and BT was applied to larvae of S. exigua, their mortality was 50.0% and weight of larvae were significantly different compare with control and only neem treatment. Therefore For effective control reducing population of beet armyworm and possibility to develop resistance against BT and eco-friendly agents, mixture of 0.016% Matrine and BT ($5{\times}10^4cfu$) could be used.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.6
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• pp.706-714
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• 2020

Currently, 90 % of the world's population breathes air with a fine dust content exceeding the World Health Organization's annual average exposure limit (10 ㎍/㎥). Global efforts have been devoted toward reducing secondary pollutants and ultra-fine dust through regulations on nitrogen oxides released over land and sea. Domestic efforts have also aimed at creating clean marine environments by reducing sulfur emissions, which are the primary cause of dust accumulation in ships, through developing and distributing environment-friendly ships. Among the technologies for reducing harmful emissions from diesel engines, electrostatic precipitator offer several advantages such as a low pressure loss, high dust collection efficiency, and NOx removal and maintenance. This study aims to increase the durability of a ship by improving equipment quality through failure mode effects analysis for the preventive maintenance of an electrostatic precipitator that was developed for reducing fine dust particles emitted from the 2,427 kW marine diesel engines in ships with a gross tonnage of 999 tons. With regard to risk priority, failure mode 241 (poor dust capture efficiency) was the highest, with an RPN of 180. It was necessary to determine the high-risk failure mode in the collecting electrode and manage it intensively. This was caused by clearance defects, owing to vibrations and consequent pin loosening. Given that pin loosening is mainly caused by vibrations generated in the hull or equipment, it is necessary to manage the position of pin loosening.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.557-562
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• 2018

Unlike live ammunition which has killing power due to the use of high explosives, training ammunition has only the limited explosive effect needed for training purposes, so the risk of accidents is lowered. Because training ammunition is used in large quantities during military drills, the problem of environmental pollution occurs. As most of the waste is left out in the training field, using bio-degradable polymers such as Polylactic Acid (PLA) can provide a solution to these environmental issues. However, bio-degradable polymers such as PLA usually have poor thermal and mechanical properties compared with other general purpose polymers, so they need to be improved before they can be used for military purposes. In this study, Talc is added to the PLA used for the parts of Training Grenades to improve some of their properties and the changes of their thermal and mechanical properties were verified. In the case of the 1 wt.% ~ 5 wt.% PLA/Talc blends, the thermal properties were improved in proportion to the content of Talc, but the best mechanical properties were observed for the 1 wt.% and 3 wt.% PLA/Talc blends.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.615-622
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• 2020

Frangible bullets, which are shredded after impact on a target, reduce the possibility of both ricochet and unexpected injury in shooting training and in mission acts in dams, nuclear power plants, and cultural properties. Reducing the levels of hazardous materials in shooting ranges, such as lead, has become an important agenda for the government and environmental groups. In this study, the shape of a frangible bullet was designed for efficient shredding, and the safety and reliability were confirmed by actual firing under different process conditions. In addition, the physical characteristics, such as compaction pressure, density, and frangibility of each process, were compared by analyzing the microstructure of the sintered frangible bullet. The experiment revealed the smallest fragmentation after impact on the target under the following conditions: Cu-Sn 85:15; sintering temperature, 600℃; sintering time, one hour. Further development of the process conditions and experimental methods will contribute to the performance and environmental improvement of a frangible bullet.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.1
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• pp.27-36
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• 2020

The study was compared for growth and yield of cherry tomato (Lycopersicon esculentum var. cerasiforme) crops as affected by various homemade liquid fertilizer (LF), commonly applied in the environmentally friendly farmhouses. LF treatment included UT (untreatment, water), OC (oil cake), BF (bone+fish meal), FA (fish amino meal), SO (sesame oil meal), and SF (starfish). Seasonal pH and EC in SO- and SF-LF rapidly decreased at 30 days after the storage, which were the highest EC of 0.6 - 0.8 dS/m, followed by BF-LF with 0.4 dS/m EC. T-N concentration in LF was the highest on the SF (0.0062%), followed by SO (0.0059%) and BF materials (0.0030%), which were all the great for the K concentration in the LF. P and Ca concentrations were the highest on the FA-LF, with the highest Mg concentration observed on the vegetable SO-LF. Soil EC was the highest on the SF-LF plots of 0.74 dS/m, with no significant differences between the treatments observed on the macro-nutrient concentrations in the soil and leaf. Leaf dry weight, leaf temperature, stem diameter, and plant height were investigated at once per 15 days. UT-LF reduced the leaf dry weight at all the measurement time while the plant height was low at an initial measurement but increased and similar to the other homemade LF treatments at a later measurement. Fruit yield and average fruit weight were the lowest on the UT-LF plots at 75 days after fertigation. Fruit diameter was increased by the BF-LF and SF-LF, with the highest fruit soluble solid contents and fruit coloring observed on the FA-LF. BF-LF maintained high fruit firmness.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.9
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• pp.527-533
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• 2017

Environmental concern about smart phone is growing because it has short product life span while having intensive production technology and cost. In this study environmental impact of the smart phone is quantified using the LCA methodology based on the ISO 14040 series standards. The assessment considers potential environmental impacts across the whole life cycle of the smart phone including; pre-manufacturing; manufacturing; distribution; product use; and end-of-life stages. The pre-manufacturing stage is the most dominant life cycle stage causing the highest environmental impacts among all 10 impact categories assessed. The global warming impacts of the smart phone in the pre-manufacturing, distribution, use, manufacturing, and end-of-life stages were 52.6% 23.9%, 15.7%, 7.0%, and 0.8%, respectively. Sensitivity of the life cycle impact assessment results to the system boundary definition and assumptions made were quite high. Three components of the smart phone, PCB, battery, and display module were identified as the key components causing majority of the potential environmental impact in the pre-manufacturing stage. As such the slim and light-weight design and the use of environmental friendly materials are important design factors for reducing the environmental impact of the smart phone.

• KIEAE Journal
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• v.15 no.3
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• pp.43-48
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• 2015

Purpose: Recently, many countries around the world are actively looking for the ways to make full use of natural energy sources and also develop and apply an environmentally friendly system designed to save building energy consumption. Under these circumstances, this study intended to determine the applicability and energy saving effect by deriving the indoor thermal performance characteristics and the PCM temperature appropriate for a double skin façade to reduce indoor energy consumption through the application of different PCM temperatures to double skin façade and perform a performance evaluation depending on the application or non-application of PCM to a double skin façade. Method: For this study, the physical variables of the double skin façade with PCM were configured through a preliminary examination based on an experimental measurement, and experimental measurements were taken with a total of 7 types of mockup cases: Type-1 (Basic), the basic double skin façade, Type-2 (PCM $18^{\circ}C$) which was applied to the inner skin of the double skin façade depending on the phase-change temperature of PCM, Type-3 (PCM $20^{\circ}C$), Type-4 (PCM $22^{\circ}C$), Type-5 (PCM $24^{\circ}C$), Type-6 (PCM $26^{\circ}C$), and Type-7 (PCM $28^{\circ}C$) with reference to the data analysis of the basic double skin façade which preceded this study, to analyze the indoor thermal performance of the double skin façade depending on PCM temperature and the installation or non-installation of a double skin façade applying PCM based on the selected unit space. Result: Indoor thermal performance was analyzed depending on the PCM temperature applicable to double skin façade, and the analysis of heating energy reduction showed that Type-2 (PCM $18^{\circ}C$) gained 15.9% more heat compared with Type-1 (Basic) and secondly, Type-3 (PCM $20^{\circ}C$) gained 11.5% more heat. Based on these findings, it is deemed possible that the use of energy for heating can be reduced when heat coming indoors increases during the heating period, and the appropriate temperature for PCM applied to the inner skin of a double skin façade to reduce heating energy in winter, Type-2 (PCM $18^{\circ}C$) showed the highest efficiency and Type-3 (PCM $20^{\circ}C$) was also deemed appropriate.

• Elastomers and Composites
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• v.46 no.2
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• pp.164-170
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• 2011

In this study, silicone rubber filled with environmentally-friendly perlite was prepared by mechanical mixing in order to improve thermal properties, such as heat and fire resistances. We found that the properties of silicone rubber composites depended on perlite concentration by various characterization methods. Thermogravimetric analysis(TGA) indicated that the initial degradation temperature of silicone/perlite composite was higher than that of pristine silicone rubber. The gas torch test showed that the opposite side temperature of composite materials was remarkably low as compared to that of pristine silicone rubber. In addition, the composites containing 5 wt% and 10 wt% of perlite showed remarkable thermal stability at elevated temperatures according to the results of both fireproof furnace tests under the RABT condition and carbonization furnace tests. The images from a scanning electron microscope(SEM) showed the degree of dispersion of perlite in silicone rubber. Finally, it was confirmed that limited oxygen index(LOI) was increased with perlite concentration.