• International Journal of Advanced Culture Technology
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• v.3 no.2
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• pp.67-76
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• 2015

This paper aims to study and design of Organic Rankine Cycle (ORC) Machine using Isopentane as working fluid expanding through Tesla turbine. The study on ORC machine expanding through Tesla turbine has result on the efficiency of Tesla turbine. In addition, Thermodynamics theory on isentropic efficiency proved to be a successful method for overcoming the difficulties associated with the determination of very low torque at very high angular speed. By using an inexpensive experiment device and a simple method, the angular acceleration method, for measuring output torque and power in a Tesla turbine is able to predict a tendency of output work. The experiments using two Tesla turbine sizes, the first size is 1.6 bigger than the second one. In comparison with the first size, the tesla turbine can produce power output more than 62% of the second size. Further study on the machine can be developed throughout the county due to its low cost and efficiency.

• Bulletin of the Korean Chemical Society
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• v.13 no.1
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• pp.83-87
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• 1992

The ring expansion of 1,3-thiazolidines 4 derived from ${\beta}$-ketoacid derivatives to the corresponding dihydro-1,4-thiazines 1 by using the action of chlorine on 4 has been achieved. In the chlorinolysis unisolable sulfenyl chlorides 5 may be formed from chlorosulfonium ions 11 by ${\beta}$-elimination involving carbonyl activated methylene hydrogens. Addition of sulfenyl chloride to the internal double bond appears to form probable thiiranium ions 14, which in turn gave 1 with loss of acidic proton. Imminium ions 15 could be hydrolyzed easily to give enol 8. As a side reaction, dihydrothiazine that was formed was further chlorinated to produce dichlorides 16 which were rearranged readily to the chloromethyl compounds 10.

• The Korean Journal of Food And Nutrition
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• v.35 no.2
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• pp.150-158
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• 2022

The purpose of this study was to assess consumption and satisfaction with fresh-cut produce in Korean adults. In this study, an online survey November 9~13, 2020 was conducted with 982 Korean adults age 19~64 (490 males and 492 females) with experience in purchasing fresh-cut produce in the past year. Among all respondents, the percentage with experience in buying 'washed or peeled vegetables' was the highest (71.18%), followed by those in buying 'packaged salads/sprouts/ssam vegetables' (64.15%), 'pre-cut fruits/fruit cups' (59.98%), 'pre-cut or minced vegetables' (56.01%), and 'washed or peeled fruits' (53.67%), respectively. Among the types of fresh-cut produce, 'packaged salads/sprouts/ssam vegetables' showed the highest satisfaction score at 3.73 pts, and the overall satisfaction score of fresh-cut produce consumption was also 3.73 pts. Compared to male respondents, female respondents showed a significantly higher percentage of respondents that purchased 'packaged salads/sprouts/ssam vegetables' (p=0.0409), significantly higher satisfaction scores (p=0.0124), and a higher percentage of respondents considering 'freshness' important when purchasing (p<0.0001). Additionally, the group with high household income comprised a significantly higher ratio of respondents considering 'eco-friendly or organic status' important. The study results may facilitate identify areas for improvement of fresh-cut produce in the future.

• Korean Journal of Food Science and Technology
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• v.38 no.5
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• pp.712-716
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• 2006

Saccharomyces cerevisiae and Zygosaccharomyces rouxii were electrofused and fermented in germaniumfortified nutrients to produce high-yield, organic germanium. The conditions for the preparation of protoplasts from both strains and for electrofusion were studied. The protoplasts of both cells formed long pearl chains and the cell membranes were lysed and fused through cellulase and high frequency voltage $(450{\sim}750V/128{\sim}512\;{\mu}sec)$. The fusants with the fastest growth were selected, and then characterized for their carbohydrate usage and tolerance to glucose and salts. The glucose tolerance of the fusants was better than that of S. cerevisiae and similar to that of Z. rouxii. The fusants appeared to have resistance to 12% NaCl. The cell size of the fusants was greater than that of the parental strains. The fusant cells contained more gemlanium than the parental cells did. The electrofusion of S. cerevisiae and Z. rouxii increased the cell capacity and accumulation of germanium in the yeasts. This method was proved to be effective to produce a high quantity of organic germanium.

• Korean Journal of Organic Agriculture
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• v.9 no.1
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• pp.1-16
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• 2001

With increasing global concern that intensively synthetic-chemical based farming systems accelerated the decline in environmental quality, the sustainability of modem agriculture became the subject of great concern. It is well known that the movement of Community Supported Agriculture(CSA) has been contributed significantly to the development of organic agriculture in USA and Japan. It was supposed that CSA could be one of the best way to promote the movement of organic agriculture since there is little reliability on the organically grown food by consumer. In this paper it was focussed to study the movement of CSA in USA and Europe in order to provide an idea for establishment and movement of CSA in Korea to support the organic agriculture. In a CSA system, the farmer grows food for a group of shareholders who pledge to buy a portion of the farm's crop that season. This arrangement gives growers up-front cash to finance their operation and higher prices for produce, since the middleman has been eliminated. For most shareholder for CSA saving money is a secondary consideration, but fresh safe products and environmentally sound farming system. People become shareholder of CSA since they expect an organic farming which can ; \circled1protect the environment, minimize pollution, promote health, \circled2replenish and maintain long-term soil fertility by providing optimal conditions for soil biological activity, \circled3maintain diversity within the farming system and its surroundings and protect plant and wildlife habit, \circled4recycle materials and resources to the greatest extent possible within the farm and its surrounding community, \circled5maintain the integrity of organic food and processed products through each step of the process from planting to consumption, \circled6develop and adopt new technologies with consideration for their long range social and ecological impact. In all CSAs, the farmer develops a crop plan and a budget, which details costs for a growing season, including fair wages for the farmers. Experienced Information on increasing shareholder retention, the future of CSA, and getting started such as ideas for ongoing marketing, printed materials that set realistic expectations, working members, production, pick-up and delivery, setting prices, and receiving feedback were also briefly introduced.

• Journal of Environmental Science International
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• v.10 no.5
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• pp.365-371
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• 2001

The optimum dosage of quicklime in producing organic fertilizer using livestock wastes vith a greater than 80% water content was analysed. After one day had elapsed to allow for the organic fentilizer to dry, the quicklime dosage and the composition of the organic fertilizer were analysed. Any from done to the organic fertilizer was also assessed. The amount of the quicklime required to stabilize livestock wastes was determined by water content of livestock wastes. For J farm(slurry style) of which livestock wastes have 94.6% of water concentration, less than 3% of total amount of livestock wastes, for H farm (scraper style) of which livestock wastes have 85% of water concentration, less then 4% of total livestock wastes and Y farm(traditional style) of which livestock wastes have 80% of water concentration, less then 5% of total livestock wastes. Generally, in order to pack the organic fertilizer, water containing quicklime0stabilized livestock wastes should be less than 35%. It takes 9 days to keep this water content for the wastes from H and Y farms(less than 85% in water content), and 12 days for the wastes from J (94.6% in water content). According to the classification standard for compost constitution by Higgins, the crude fertilizers from all 3 farms had high grade $K_2O$ and CaO, the middle grade T-N and middle or low grade $P_2O_5$. Stabilization by quicklime is known to inhibit bacterial decomposition of organic matter and the activity of pathogenic organisms. In this study, more then 99.99% of coliform group, fecal group and viable cell count were reduced. Our results indicate that livestock wastes of greater 80% water content could be used to produce organic fertilizer without the addition of a material for moisture control.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.4
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• pp.69-76
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• 2016

To produce the primary data for best management of soil nutrient in organically practiced soils, 75 leading organic farms whose paddy fields were certified as organic were selected. Soil samples were collected from the paddy fields before plowing, and then analyzed for the determination of physico-chemical properties. Soil pH, organic matter and available phosphate were analyzed and averaged 6.2, $25.6mg\;kg^{-1}$ and $88.4mg\;kg^{-1}$, respectively. Contrary to the national-scale-surveyed paddy soils including organic and conventional farming, pH was higher, available phosphate was lower in the organically practiced soils, but organic matter was similar. With the increasing cultivation period in organic, soil pH and porosity were also increased, EC, available phosphate, bulk density and soil hardness were lower than those from the national survey. Organic matter, however, was not significantly changed. The bulk density was negatively correlated with the organic matter content for both surface topsoil ($R^2=-0.5424$) and subsoil ($R^2=-0.6429$) (p<0.05). Soil quality is improved in most of soil chemical and physical composition factors excluding organic matter and available phosphate. However, it is necessary to establish the counter measure plan for organic matter management and to develop phosphate-containing materials which can be used as organic agricultural material in the future.

• Microbiology and Biotechnology Letters
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• v.50 no.2
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• pp.202-210
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• 2022

Aflatoxin contamination in rice has been documented in a number of studies, and has a high incidence in Asian countries, and as such, there has been a growing interest in alternative biocontrol strategies to address this issue. In this study, 147 strains of yeasts and yeast-like fungi were screened for their potential to produce volatile organic compounds (VOCs) active against Aspergillus flavus strains that produce aflatoxin B₁ (AFB₁). Five strains within four different genera showed greater than 50% growth inhibition of some strains of A. flavus. These were Anthracocystis sp. DMKU-PAL124, Aureobasidium sp. DMKU-PAL120, Aureobasidium sp. DMKU-PAL144, Rhodotorula sp. DMKU-PAL99, and Solicococcus keelungensis DMKU-PAL84. VOCs produced by these microorganisms ranged from 4 to 14 compounds and included alcohols, alkenes, aromatics, esters and furans. The major VOCs produced by the closely related Aureobasidium strains were found to bedistinct. Moreover, 2-phenylethanol was the most abundant compound generated by Aureobasidium sp. DMKU-PAL120, while methyl benzeneacetate was the major compound emitted from Aureobasidium sp. DMKU-PAL144. On the other hand, 2-methyl-1-butanol and 3-methyl-1-butanol were significant compounds produced by the other three genera. These antagonists apparently inhibited A. flavus sporulation and mycelial development. Additionally, the reduction of the AFB1 in the fungal-contaminated rice grains was observed after co-incubation with these VOC-producing strains and ranged from 37.7 ± 8.3% to 60.3 ± 3.4%. Our findings suggest that these same microorganisms are promising biological control agents for use against aflatoxin-producing fungi in rice and other agricultural products.

• Food Science and Preservation
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• v.13 no.2
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• pp.246-251
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• 2006

Organic compost is a useful fertilizer for organic farming. However, it poses a microbiological hazard to the farm produce because most of the compose are originated from excrementitious matters of domestic animals. Irradiation was performed to improve microbiological safety of organic compost and the effectiveness of gamma-irradiation for inactivating Salmonella typhimurium and E. coli was investigated. Total aerobic bacteria and coliform bacteria in 16 produce or commercial compose were ranged from $10^5\;to\;10^7\;CFU/mL\;and\;0\;to\;10^3\;CFU/mL$, respectively. All coliform bacteria in the composts were eliminated by irradiation at 5 kGy, while about $10^2\;CFU/mL$ of total aerobic bacteria survived up to 10 kGy of irradiation. In the inoculation test the test organisms (inoculated at $10^7\;CFU/mL$) were eliminated by irradiation at 3 kGy. $D_{10}$ values of inoculated Salmonella typhimurium and E. coli in the compost were $0.4{\pm}0.05\;and\;0.39{\pm}0.03kGy$. It was considered that $3{\sim}5kGy$ of gamma irradiation was effective for radicidation (radiation sterilization of pathogenic microbes) of organic fertilizer.

• KSBB Journal
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• v.23 no.4
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• pp.340-344
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• 2008

Coprinus cinereus peroxidase (CiP) was often used as a catalyst for oxidative polymerization of a variety of phenol derivatives to produce a new class of polyphenols. Economical point of view, to know the mechanism of enzyme deactivation is significantly important because cost of enzyme is critically high. Hydrogen peroxide being used as oxidizing agent induced deactivation of peroxidase by destruction of heme structure. In the presence of hydrogen peroxide the stability of peroxidase was unexpectedly improved by adding organic solvent. Especially 2-propanol significantly improved enzyme stability among tested solvents. Radical scavenging by organic solvents may play a major role in protecting peroxidase from the oxidation of oxidizing radicals.