• 유기물자원화
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• 제27권3호
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• pp.27-39
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• 2019

본 연구에서는 음식물류 폐기물과 하수슬러지의 효과적인 병합 혐기성 처리를 위한 열화학적 가수분해 방법의 최적 조건 평가와, 열화학적 가수분해에 따른 병합 혐기성 소화 효율에 대해 평가 하였다. 열화학적 가수분해는 온도 (80, 100, 120, 140, 160, $180^{\circ}C$)와 NaOH (5, 20, 40, 60, 100 meq/L) 조건에 따른 solubilization COD, CST(Capillary Suction Time), TTF(Time to Filter), volatile fatty acids (VFAs) 등에 대해 평가를 하였으며, 병합 혐기성 소화 효율평가는 biochemical methane potential (BMP) test를 통해 평가하였다. 실험결과 음식물류폐기물과 하수슬러지의 열화학적 가수분해 시 온도 $140^{\circ}C$, NaOH 60 meq/L에서 solubilization COD 20 % 이상, CST와 TTF가 60초 이하, VFAs 농도가 12,000 mg-COD/L 이상으로 최적조건으로 규명되었다. 병합 혐기성 소화 결과도 열화학적 가수분해 조건과 동일한 조건에서 가스발생량이 가장 높았다. 따라서, 음식물류폐기물과 하수슬러지의 효과적인 병합혐기성소화를 위한 열화학적 가수분해 전처리 조건은 온도 $140^{\circ}C$, NaOH 주입농도 60 meq/L라 판단된다.

• Bulletin of the Korean Chemical Society
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• 제27권10호
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• pp.1613-1617
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• 2006

Optimum analytical conditions for cyclic voltammetry (CV) and square wave (SW) stripping voltammetry were determined using mercury-mixed carbon nanotube paste electrode (PE). The results approached the microgram working ranges of SW: 10.0-80.0 $ugL^{-1}$ and CV: 100-700 $ugL^{-1}$ Cd (II); working conditions of 300-Hz frequency, 100 mV amplitude, 1.6 V accumulation potential, 400 sec accumulation time, and 40 mV increment potential. First, analysis was performed through direct assay of cadmium ions deep into the fishs brain core and plant tissue in real time with a preconcentration time of 400 sec. The relative standard deviation of 10.0 $mgL^{-1}$ Cd (II) observed was 0.064 (n = 12) at optimum conditions. The low detection limit (S/N) was set at 0.6 $ugL^{-1}$ ($5.33{\times}10^{-9}$ M). The methods can be used in direct analysis in vivo or in real-time monitoring of plant tissue.

• 한국자동차공학회논문집
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• 제10권3호
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• pp.136-142
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• 2002

HFC-134a is currently used as the refrigerant in automobile air-conditioner, replacing the ozone depleting refrigerant CFC-12. Although HFC-l34a has no ozone depletion potential, it has a relatively high global warming potential, approximately 1300 tins that of CO$_2$ over a 100 year time horizon. Therefore, HFC- l34a does not seem to be a perfect alternative refrigerant due to high GWP. For this reason, non-azeotrope refrigerant mixture have been proposed as a long-term and drop-in alternative to HFC-l34a in the automobile air-conditioning system which has variable operating conditions with changes in RPM and pressure ratio. In this study,OS-l2a of which thermodynamic properties are similar to those of HFC-l34a is selected among the mixed refrigerant. HFC-l34a and OS-l2a are examined experimently by the performance test in the same automobile air-conditioning system.

• Asian-Australasian Journal of Animal Sciences
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• 제13권2호
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• pp.265-276
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• 2000

Crop-animal systems which form the backbone of agriculture in the tropics are discussed with reference to their characteristics, economic importance of animals, genesis and types of crop-animal systems, relevance and potential importance, and priorities for research and development. These production systems are found across all agroecological zones: rain-fed temperate and highland systems, semi-arid and arid tropics, and sub-humid and humid tropics: the last four are priority areas in Asia. The potential importance of these systems in Asia is reflected in their advantages, synergism and complimentarity, economic benefits and contribution to sustainability. Illustrative case studies are cited which are appropriate to the two broad types of mixed farming systems: systems combining animals and annual cropping, and systems combining animals with perennial cropping with reference to Indonesia, Philippines, Malaysia, Sri Lanka, China and Nigeria. Priorities for research and development should address more complete use of the animal genetic resources, intensive utilisation of the feed resources, development-oriented utilisation of research results, minimizing animal diseases, and implementation of appropriate institutional and policy issues.

• Journal of Forest and Environmental Science
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• 제32권4호
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• pp.392-399
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• 2016

This review paper presents guidelines which stakeholders use in addressing on-farm tree planting configuration, establishment, tending, silvi- cultural management, management of pests and diseases, challenges and opportunities as practiced in the medium to high potential areas of Kenya. The tree planting configurations discussed includes blocks planting (woodlot), boundary, compound planting, home/fruit gardens, trees intercropped or mixed with pasture, trees on riverbanks and roadside. Participatory monitoring and evaluation techniques have been highlighted. The main challenges facing tree planting activities include culture and attitude of local people, land and tree tenure, inadequate technical support, lack of recognition and integration of technical information and indigenous knowledge, capital and labour shortages, lack of appropriate incentives measures, damage by domestic and wild animals, conflict over trees on the boundary and policy and legal issues. This guideline targets forest managers, extension agents, students and other practitioners in policy and day to day decision making processes in Kenya.

• Bulletin of the Korean Chemical Society
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• 제32권2호
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• pp.620-624
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• 2011

In recent years, the study of self-assembly peptide used in drug delivery system has been attracted great interest from scientists. In the category are self-assembly peptides in the structure either with one hydrophobic surface and another hydrophilic or a hydrophobic head and a hydrophilic tail. Here, we focus on a novel designed peptide EYK with double amphiphilic surfaces, investigating on the capability of peptide as a carrier for hydrophobic compound model pyrene. The fluorescence data presented the dynamic process of the transfer, showing that the pyrene was in the crystalline form in peptide solution, and molecularly migrated from its peptide encapsulations into the membrane bilayers when the peptide-pyrene suspension was mixed with liposome vesicles. The results indicated that the peptide EYK could stabilize hydrophobic pyrene in aqueous solution and delivered it into EPC liposome as a potential carrier.

• Asia pacific journal of information systems
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• 제13권3호
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• pp.63-84
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• 2003

Business process redesign(BPR) has been widely adopted as an organizational change method since 1990s as the competitive pressures have forced organizations to constantly change. Although BPR has provided successful stories to gain dramatic improvement in performance and has been promoted as an enabler of organizational change, many organizations have faced serious challenges with widely mixed results due to the lack of understanding for potential organizational conflicts and the improper targeting of critical processes in the initial stage of BPR. This paper proposes a cognitive map based method to help organizational members identify potential organizational conflicts, capture core business activities, and suggests guidelines to lead to the necessary organizational change. A computerized tool has been developed to support the real world cases. Working procedure of the proposed method is illustrated with its application to the real BPR project of a dairy company.

• Transactions on Electrical and Electronic Materials
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• 제7권3호
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• pp.108-111
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• 2006

The oxidizer-induced corrosion state and microstructure of surface passive metal-oxide layer greatly influenced on the removal rate of tungsten film according to the slurry chemical composition of different mixed oxidizers. In this paper, the actual polishing mechanism and pH-potential equilibrium diagram obtained from potentiodynamic polarization curve were electrochemically compared. An electrochemical corrosion effect implies that slurries with the highest removal rate (RR) have the high dissolution rate.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2544-2547
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• 2008

A micro channel heat sink has been studied and optimized for mixed pressure driven and electroosmotic flows through three-dimensional numerical analysis. The effects of ionic concentration represented by zeta potential and Debye thickness are studied with the various steps of externally applied electric potential. Optimization of the micro channel heat sink has been performed considering two design variables related to the micro channel width, depth and fin width. The surrogate-based optimization is performed using a search algorithm taking overall thermal resistance as objective function. The thermal resistance is found to be more sensitive to channel width-to-depth ratio than fin width-to-depth of channel ratio.

• 한국컴퓨터정보학회논문지
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• 제21권9호
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• pp.165-176
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• 2016

This study developed the learning ability-based smart education program. The effectiveness of the developed materials was investigated using the quantitative-qualitative mixed method, and the process and results of the investigation are as follows. The quantitative investigation was conducted using the non-equivalent pretest-posttest design, in which the smart education method was applied to the experimental group, while the conventional education method was applied to the control group to analyze students' creative problem-solving potential, task concentration, and the variables required for the learning activity. The results showed significantly higher performance in the experimental group over the control group. Regarding data collection in the qualitative investigation, an analysis of the class from the instructor and class consultation logs from the class analyst were collected; the comments on the experience of each class period were collected from students. The results of the analysis of the data suggest that the perception of smart education improved for the instructor, class analyst, and learners as the course progressed.