• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.120-127
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• 2011

For the development of the environment-friendly insulating composite materials, natural cellulose (wood chip and sawdust) was used as a core material and activated Hwangtoh was used as a binder. Various specimens were prepared with the water/binder ratio and natural cellulose/binder ratio. The physical properties of these specimens were then investigated through compressive and flexural strength test, absorption test, hot water resistance test, thermal conductivity, measurement of pore distribution and observation of micro-structures using scanning electron microscope (SEM). Results showed that the absorption ratio increased with the increase of natural cellulose/binder ratio but decreased remarkably with the increase of polymer/binder ratio. The compressive and flexural strength development varied appreciably with the increase of water/binder ratio and natural cellulose/binder ratio. On the other hand, thermal conductivity decreased with the increase of natural cellulose/binder ratio and polymer/binder ratio. Through SEM, it was found that activated Hwangtoh that reacted with water formed a hydrate crystal leading to the compact structure and the total pore volume of the specimen using activated Hwangtoh was smaller than that of the non-activated Hwangtoh.

• The Korean Journal of Pesticide Science
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• v.11 no.1
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• pp.38-45
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• 2007

Laboratory and greenhouse experiments were conducted to determine the herbicidal effect of two types of ${\delta}$-aminolevulinic acid (ALA), microbiologically-produced ALA (Bio-ALA) and synthetically produced ALA (Synthetic-ALA), on plant growth and chlorophyll content of Chinese cabbage. ALA effect on early plant growth was greatly concentration dependant, showing significant inhibition at higher concentrations. Both pre- and post-emergence application of ALA exhibited significant degree of photodynamic phytotoxicity. Older plants with many leaves were more tolerant to ALA than younger plants, showing less injury. No significant difference in herbicidal activity of two types of ALA, Bio-ALA and Synthetic-ALA, on plant height and chlorophyll content of Chinese cabbage was observed. However, residual biological activity and physico-chemical properties of Synthetic-ALA were more stable than those of Bio-ALA. Our results suggest that ALA had herbicidal potential with both pre- and post-emergence application, and that the chemical may be a valuable mean of eco-friendly weed control based on natural microbial substance.

• Applied Chemistry for Engineering
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• v.27 no.6
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• pp.573-576
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• 2016

In this study, hydrogenation of 1,2,3,3,3-pentafluoropropene was performed to produce R-1234yf as an environmentally friendly refrigerant. Palladium based carbon was prepared as a catalyst in the hydrogenation reaction. The effect of reaction conditions including the weight hourly space velocity (WHSV), reaction temperature and ratio of hydrogen and reactants on the catalytic performance was investigated. Under the identical reaction conditions, the effect of WHSV on the main product selectivity was insignificant, but a high reaction temperature was essential for the good product selectivity. A high product selectivity was also obtained when the ratio of hydrogen and reactants kept less than 1.5. Moreover, a correlation model involving the statistical approach to predict product yields was developed.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.2
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• pp.97-104
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• 2021

Together with the emerging of the Eco-ship, the application of large-diameter and high-efficiency propeller required more careful attention than before in the design of the shafting system. After the adoption of Environmentally Acceptable Lubricants (EAL) to the stern tube lubrication oil, a number of aft stern tube bearing accidents have been reported, and a variety of institutions have actively conducted research on the cause relationship. This study attempted to find the cause of the accident by measuring the alignment of the shafting system of a medium-sized product/chemical tanker with aft stern tube bearing damage and analyzing the reaction force of each bearing. In addition, a reasonable solution to the correction of the shaft alignment was suggested and the feasibility was reviewed. Through various measured data and analysis, the actual installation of shafting system was slightly different from the design drawing condition, but it was found that each bearing load distribution was within the allowable range. Therefore, it was confirmed that the cause of this accident was due to the dissatisfaction the misalignment slope of aft stern tube bearing rather than the effect of the bearing overload. As a solution to this cause, countermeasures such as double slope were suggested in the aft stern tube bearing, and the characteristics of EAL also seem to have an indirect effect.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.4
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• pp.17-31
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• 2023

Amidst escalating global warming fueled by indiscriminate fossil fuel consumption, concerted efforts are underway worldwide to mitigate atmospheric carbon dioxide (CO₂) levels. Electrochemical CO₂ reduction technology is recognized as a promising and environmentally friendly approach to convert CO₂ into valuable hydrocarbon compounds, deemed essential for achieving carbon neutrality. Copper, among the various materials used as CO₂ reduction electrodes, is known as the sole metal capable of generating C₂₊ compounds. However, low conversion efficiency and selectivity have hindered its widespread commercialization. This review highlights diverse research endeavors to address these challenges. It explores various studies focused on utilizing copper-based electrodes for CO₂ reduction, offering insights into potential solutions for advancing this crucial technology.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.100-107
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• 2007

People have spent lots of time inside building about 90% of these day. Industry has been developed rapidly after I960. Construction materials had changed from natural materials to chemical materials and confidentiality of building has been more higher than before by policy of saving energy. These have caused sick-building syndrome (SBS) for us. So people want environmental construction materials for their house. We designed a environmental loess (yellow soil) finishing material which was composed of loess, water, water-soluble resin, hardener and filler. The purposes of this study were that making an environmental loess finishing material with optimum ratio, evaluating the usability of loess finishing material for wall. Furthermore it was suitable for wall to evaluate mechanical properties that are impact test, cracking test, abrasion test and de-bonding test, environmental properties that were emission of VOCs, formaldehyde and far infrared radiation.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.322-322
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• 2009

국내산 밀을 유기농 재배하여 친환경 농산물 인증을 받으려면 파종에 필요한 종자도 유기농으로 생산된 것(유기종자)을 사용해야한다. 국립식량과학원에서는 유기종자 생산용 밀 품종 선발을 위한 연구를 수행하고 있으며, 관련 시험으로서 유기질 비료 시비가 밀의 농업형질 및 종자의 아미노산 함량에 미치는 영향을 검토하였다. 무비, 화학비료 및 유기질 비료를 시비한 시험구에 금강밀 등 24개 밀 품종을 파종하여 시험 구별로 출수기 등 농업형질과 수확된 종자의 아미노산 함량을 분석하였다. 밀의 출수기는 시비 조건에 따른 영향을 받지 않았으나 성숙기는 유기질 비료 시비조건에서 화학비료 및 무비보다 1일과 2일 지연되었다. 밀의 간장, 수장, 수수, 수당립수 및 L중은 시비의 종류에 따른 차이를 나타내지 않았다. 한편, 유기질 비료 시비에 따른 밀 종실수량(368.4kg/10a)은 무비 및 화학비료보다 각각 25%와 8% 유의하게 증가하였다. 밀 종자의 전체 아미노산 함량은 무비<화학비료<유기질비료 순으로 유의하게 증가하였다. 각각의 아미노산별로 시비조건에 따른 함량차이를 조사한 결과, Glutamate 등 13종의 아미노산은 시비조건에서 5~16% 증가하였다. Alanine 함량의 경우 무비조건에 비하여 유기질 비료 시비조건에서 38% 증가하였으나 화학비료 시비조건에서는 12% 감소하였다. 한편, tyrosine, phenylalanine 및 proline은 유기질 비료 시비조건에서 11~29% 감소하였으나, 화학비료 시비조건에서 9~36% 증가하였다.

• Membrane Journal
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• v.33 no.6
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• pp.369-376
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• 2023

In this study, the alternative to the energy-intensive conventional vacuum distillation process, an eco-friendly and energy-efficient pervaporation separation was employed in 1,2 hexane diol/water (HDO/water) mixture. The crosslinked PVA-glutaraldehyde was coated inside the alumina hollow fiber membrane (Al-HF). In the HDO/IPA pervaporation separation, optimization of the membrane concerning PVA/GA ratio, curing temperature, and pervaporation operating condition were performed. In the long-term stability test, the sustainable pervaporation separation performance giving flux in the range of 1.90~2.16 kg/m²h, and water content in permeate was higher than 99.5% (separation factor = 68) was obtained from the PVA/GA (molar ratio = 0.08, curing temperature = 80℃) coated Al-HF membrane from HDO/water (25/75, w/w, %) mixture at 40℃. Therefore, this work provides potential and inspiration for PVA-based membranes to mitigate excessive energy requirements in HDO/water separation by pervaporation.

• 농업기술회보
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• v.47 no.1
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• pp.33-34
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• 2010

최근 화학비료의 가격이 올라 농가경영에 부담이 될 뿐만 아니라 2012년 이후에는 가축분뇨의 해양배출을 전면 금지해야 하는 시점에서 농경지에 가축분뇨 액비의 환원은 매우 중요한 해결방안이 될 수 있다. 가축분뇨 액비를 농경지에 환원하면 직물에 양분공급, 토양 비옥도 증가 및 토양생물의 활성유지 등 다양한 효과가 있다. 그러나 필요량 이상으로 사용하면 작물이 웃자라 쓰러져 수량감소와 품질저하는 물론 생산기반인 토양과 수질 등 환경에 나쁜 영향을 초래할 수가 있어 사용기준을 잘 지켜야 한다.

• KOREAN POULTRY JOURNAL
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• v.35 no.11 s.409
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• pp.86-90
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• 2003

정부는 증산위주의 고투입농법에 의존한 결과 화학비료 과다사용으로 토양의 양분의 불균형을 초래하고 있으며, 환경보전 및 식품안전에 대한 국민의 관심이 커짐에 따라 2000년부터 친환경농업 5개년 계획을 수립하여 추진하고 있다. 이 계획에 따라 축산분뇨 자원화를 서두르고 있다. 특히 자원화 효율이 좋은 계분은 경정농가로부터 인기가 매년 상승하고 있는 상태이다. 그러나 경종농가에 판매되는 발효 계분은 현행 비료관리법상 1일 생산되는 부산물비료가 1일 1.5톤이상이면 비료업 등록을 하도록 되어 있으며, 비료업에 등록하여 발효계분을 판매하고 싶어도 각종 규제에 걸려 판매하지 못하는 농가가 많고, 계분판매는 엄두도 내지 못하고 오히려 비용을 지불하고 있는 농가들이 있어 이에 대한 현황을 점검하고 해결방안을 알아보았다.