• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.348-361
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• 2015

To reduce the effects of greenhouse gas (GHG) emissions, the government has announced the special platform of technologies as parts of an effort to minimize global climate change, and the government distributed biodiesel since 2006 as the further efforts. Although there are some debates about some quality specifications and unbalanced of source (44% from palm oil), more than 400kton/year of biodiesel was produced in 2013. Moreover the amounts will be increased when the RFS is activated. To solve the unbalanced situation and to achieve the diversity of feeds, it is essential that many researches should be considered. Especially, free and bond glycerines are one of the important properties seriously affected to the combustion system in vehicle & cold properties. Previous method (KS M 2412) couldn't cover the biodiesel derived from lauric oil($C_{12:0}$) such as PKO (Palm Kernel Oil), Coconut oil because those compositions are lighter than other conventional biodiesel sources. In this study, we review the existed method and figure out the factors should improve to analysis the glycerine from PKO and Coconut oil biodiesel. Modifying the analysis conditions to enhance the resolution and change the internal standards to avoid the overlapped- peaks between Capric acid ME ($C_{10:0}$) and standard#1(1,2,4-butantriol). From this revised method, we could solve the restrictions of previous methods. And check the possibility of new method to analyze the glycerine in biodiesel regardless of sources.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.1-8
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• 2016

Current sensors are used widely in the fields of current control, monitoring, and measuring. They have become more popular with the increasing demand for smart grids in a power network, generation of renewable energy, electric cars, and hybrid cars. Although open loop Hall effect current sensors have merits, such as low cost, small size, and weight, they have low accuracy. This paper describes the design and fabrication of a 300A open loop current sensor that has high accuracy and temperature performance. The core of the current sensor was calculated numerically and the signal conditioning circuits were designed using circuit analysis software. The characteristics of the manufactured open loop current sensor of 300 A class was measured at currents up to 300 A. According to the test of the current sensor, the accuracy error and linearity error were 0.75% and 0.19%, respectively. When the temperature compensation was carried out with the relevant circuit, the temperature coefficients were less than $0.012%/^{\circ}C$ at temperatures between $-25^{\circ}C$ and $85^{\circ}C$.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.9
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• pp.793-802
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• 2009

Adsorption properties were estimated for the organic silicon compounds (siloxanes) in an actual landfill gas (LFG) using adsorbents such as coconut activated carbon, coal activated carbon, silica gel, sulfur adsorbent, carbonized sludge, and molecular sieve 13X. Coconut activated carbon showed the highest removal efficiency of more than 95%. The desorption of hexamethyldisiloxane (L2) from the adsorbent, however, resulted in the remarkable concentration variation of the compound in the treated gas. Silica gel, which had high adsorption capacity for L2 in single substance adsorption experiment in the other study, could not remove the component in the actual landfill gas while it adsorbed well octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) in the LFG. Therefore the elimination of hexamethyldisiloxane is an important factor to determine the level of total organosilicon compound in pretreated landfill gas. Moreover, the L2 from the actual landfill gas was effectively adsorbed by the serial adsorption test using two columns packed with coconut activated carbon which has the great capacity of siloxanes removal among others. In order to utilize efficiently LFG as a renewable energy, the emission and adsorptive characteristics of the substance to be treated should be considered for the organization, operation, and management of pretreatment process.

• Journal of Environmental Policy
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• v.10 no.3
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• pp.21-48
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• 2011

The paper affirms the weight proportion concept as an element, which could be empirically analyzed quantitatively through the developmental expansion of qualitative empirical analysis on taxonomy that is required for the construction Low-Carbon Green Cities and their eco-friendly elements, such as a pleasant residential environment The weight proportion concept is proposed as a new measure to identify eco-friendly elements and as an objective assessment indicators. To perform an empirical analysis, surveys were first given to the residents of Metropolitan Newtown (50 persons) and outside experts (50 persons) for the total of 100 persons. Second, the paper surveyed 74 sites of Eco-Environmental Certified Apartment Housing Complexes. Upon analysis of eco-friendly elements by their type and total weight, the largest weight proportion was expressed in the interior and eco-environmental elements, carbon-decrease types, and carbon-absorption types. The results of this paper confirm recent positive sentiments and preference toward a variety of future-oriented and sustainable eco-friendly elements like the eco-housing and new renewable energy, In addition, the paper affirmed the new housing trend towards constructing eco-friendly elements, such as carbon-decrease and carbon-absorption, that induce long-term investments, despite their need for higher investments.

• Journal of Mushroom
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• v.8 no.4
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• pp.161-164
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• 2010

For the development of a sporeless strain of P. ostreatus we used sporeless strain ASI 2069. We have recovered both nuclear types of strain ASI 2069 as monokaryons of nh9, nh15, nh26 and nh36 (here after referred to as neohaplonts) by protoplasting the mycelium. Crosses between neohaplonts and SSI's(single spore isolates) obtained from a sporulating commercial strain ASI 2180. Five excellent strains are selected from 30 bred strains by quality of fruitbodies and spore number. To development of molecular markers linked to sporeless strain of P. ostreatus, we are screened helicase, recombinase(DMC1) and topoisomerase(Spo11) genes related meiosis by PCR and sequencing. Among three genes, Spo11 gene was identified into molecular marker of sporeless from neohaplonts and bred strains of P. ostreatus.

• Economic and Environmental Geology
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• v.45 no.5
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• pp.589-597
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• 2012

Recently, an understanding of new sources of liquid hydrocarbons such as bioethanol is economically very important. Bioethanol is actually ethyl alcohol or also referred to as ethanol, identical to drinking alcohol by its composition. There are mainly two ways of producing ethanol, namely by synthesis of hydrocarbons and from biomass. Only the second approach deserves the terminology 'bioethanol'. The present dissertation is also designed with purpose of developing the energy-saving process for the separation of bioethanol. The world population is expected to grow past 8 billion by 2030 which are almost 60% in Asia Pacific. History has shown that energy use rises much faster than population expands. World wide demand for energy will increase significantly during the next 15 years driven by population growth and the transition of emerging markets into the global economy. In developing nations, a smaller increment in GDP per capita yields a higher increment in energy consumption compared to developed countries. In this study, we analised total 2,454 dissertations for the bioethanol during the 2001~2012 periods by the programs of 'web of science' and 'recently developped program by Korea Institute of Science Technology Information'.

• Korean Journal of Plant Tissue Culture
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• v.25 no.1
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• pp.63-68
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• 1998

Multiple shoots obtained in MS medium suppler with 5.0 mg/L BA though shoot-tip culture. The frequency of vitrified shoot was lower on Bacto-agar medium than on Gelrite as gelling agent. Addition of activated charcoal at concentrations of 0.1~0.3% reduced vitrification and markedly increased shoot growth, and formation and growth of roots, but significantly reduced the number of shoots formed. The ratio of fresh weight to dry weight was decreased by increasing light intensity and agar concentration. Eight-tenths times of macroelement of MS medium was observed to be effective for shoot formation. Addition of IAA effectively promoted shoot formation in both shoot tip and node-bud explants. Supplement of 5.0 mg/L BA, 0.3 mg/L IAA to MS medium was most effective in shoot proliferation on shoot tip and node-bud explants.Multiple shoots obtained in MS medium suppler with 5.0 mg/L BA though shoot-tip culture. The frequency of vitrified shoot was lower on Bacto-agar medium than on Gelrite as gelling agent. Addition of activated charcoal at concentrations of 0.1~0.3% reduced vitrification and markedly increased shoot growth, and formation and growth of roots, but significantly reduced the number of shoots formed. The ratio of fresh weight to dry weight was decreased by increasing light intensity and agar concentration. Eight-tenths times of macroelement of MS medium was observed to be effective for shoot formation. Addition of IAA effectively promoted shoot formation in both shoot tip and node-bud explants. Supplement of 5.0 mg/L BA, 0.3 mg/L IAA to MS medium was most effective in shoot proliferation on shoot tip and node-bud explants.

• Korean Journal of Plant Tissue Culture
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• v.21 no.4
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• pp.239-246
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• 1994

The genotypic (2n, 3n, 4n) response of watermelon in vitro shoot tip culture was evaluated. Different genotypes had similar response in terms of shoot formation and growth. Shoot formation was better at lower concentration of 0.3 mg/L BA and higher concentration of 5-10.0 mg/L 2iP and kinetin, but growth of newly formed shoot was inhibited. With further subculture, kinetin did not promote shoot formation Better shoot formation was observed at 0.3-0.5 mg/L BA. Combination of 0.3 mg/L BA and 0.3-0.5 mg/L BA was effective in shoot multiplication, growth and induction of more internodes. Varrying levels of light intensity and agar concentration did not affect the performance of tetraploid plants. Higher light intensity and agar concentrations decreased the number of shoot formed in triploid plane. Growth in both genotype, however was inhibited. Higher light intensity was found to promote leaf senescence in all genotypes. All growth inhibitors decreased the number of shoots formed and slowed plant growth there by prolonging duration of cultures. Growth inhibitors were to observed to decrease incidence of hyperhydricity in culture. No difference in shoot formation was observed in each of the concentrations used in Ancymidol, TIBA, CCC and PP333. Shoot formation and growth was more inhibited in ABA treatments. Leaf expansion and growth was poor in all treatments.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.396-400
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• 2015

To investigate the optimal conditions for shoot organogenesis in Astragalus sinicus L., hypocotyl explants were cultured in Murashige & Skoog's (MS) medium supplemented with 0.1, 1.0, 2.0, or 4.0 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) for 6 weeks. 2,4-D concentration significantly effected morphogenesis: some produced calli with adventitious shoots and roots, some produced calli with adventitious roots, some produced only calli, and some produced deep-brownish calli with roots. The formation of calli with shoots and/or roots was observed at lower levels of 2,4-D, whereas calli without shoots or with deep-brownish roots were formed after treatment with higher levels of 2,4-D. Also, a shoot organogenesis ability of callus clones was observed after treatment with medium with 0.1 or 1.0 mg/L 2,4-D grown in MS medium with combinations of benzyl adenine (BA) and 2,4-D for 4 weeks. Medium with a combination of BA and 2,4-D was effective for shoot formation, whereas root organogenesis from calli decreased. The greatest amount of shoot formation was obtained when calli were cultured in MS medium containing 1.0 mg/L 2,4-D and 0.5 mg/L BA. Upon shoot transfer into 1/2 MS basal medium, plantlets developed, and the plantlets grew well in soil in a greenhouse.

• Journal of the Korean Vacuum Society
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• v.16 no.3
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• pp.161-166
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• 2007

Photovoltaic (PV) technology permits the transformation of solar light directly into electricity. For the last five years, the photovoltaic sector has experienced one of the highest growth rates worldwide (over 30% in 2006) and for the next 20 years, the average production growth rate is estimated to be between 27% and 34% annually. Currently the cost of electricity produced using photovoltaic technology is above that for traditional energy sources, but this is expected to fall with technological progress and more efficient production processes. A large scale production of solar grade silicon material of high purity could supply the world demand at a reasonably lower cost. A shift from crystalline silicon to thin film is expected in the future. The technical limit for the conversion efficiency is about 30%. It is assumed that in 2030 thin films will have a major market share (90%) and the share of crystalline cells will have decreased to 10%. Our research at Sungkyunkwan University of South Korea is confined to crystalline silicon solar cell technology. We aim to develop a technology for low cost production of high efficiency silicon solar cell. We have successfully fabricated silicon solar cells of efficiency more than 16% starting with multicrystalline wafers and that of efficiency more than 17% on single crystalline wafers with screen printing metallization. The process of transformation from the first generation to second generation solar cell should be geared up with the entry of new approaches but still silicon seems to remain as the major material for solar cells for many years to come. Local barriers to the implementation of this technology may also keep continuing up to year 2010 and by that time the cost of the solar cell generated power is expected to be 60 cent per watt. Photovoltaic source could establish itself as a clean and sustainable energy alternate to the ever depleting and polluting non-renewable energy resource.