• Korean Journal of Organic Agriculture
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• v.26 no.3
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• pp.351-367
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• 2018

This study aimed to analyze socioeconomic effect of eco-friendly free school food supply system by Seoul, which has been consistently extended since 2011. To do so, effect of eco-friendly free school food supply system on the beneficiaries, Seoul citizens, was analyzed by using 'labor & income panel', while that on rural society was analyzed by using the surveys on the eco-friendly agricultural product supply performance by the 'Eco-friendly Agricultural Products Retail Center' as well as for students, school parents, nutrition teachers and nutritionists. The results of analysis showed that eco-friendly school food supply system contributes to income redistribution among the Seoul citizens to a certain extent, provides the eco-friendly agricultural product producers in the rural society with the stable market, and positively influences them to secure stable incomes. In addition, eco-friendly free school food reduced the amount of carbon emissions through the use of environmentally friendly agricultural products resulting in environmental improvements and economic benefits. Considering such effects, free school food supply using the eco-friendly agricultural products needs to be consistently maintained in the future without politic change by political ideology and to be extended to middle school level in medium and short-term.

• The Microorganisms and Industry
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• v.26 no.1
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• pp.18-30
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• 2000

Three kinds of organic matter such as glucose, oxalic acid, and ethanol were added to the media(N-free or NO$\_$3/-riched) and their effects on the nitrogen fixation of Nostoc pruniforme were measured by manometric technique through the experiments in vivo. 1) The organic matters used in this experiments showed effective results as a role of substrate for the fixation of atmospheric nitrogen. 2) In the nitrogen-free medium treated with the both of flucose nad ethanol, the highest nitrogen uptakes were detected in the treated of low concentrations (glucose ; 0.1%, 0.5%, ethanol : 0.1%, 0.5%). On the contrary, the highest nitrogen uptakes in NO$\_$3/-riched medium were measured at the treated of high concentrations (glucose ; 2%, 1%, ethanol ; 1.5%, 1.0%). 3) The highest nitrogen uptakes in N-free medium treated with oxalic acid were measured at the concentration of 2% and 1%, respectively. In the medium of NO$\_$3/-riched, the nitrogen uptakes were in the opposite directions.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.306-312
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• 1998

Free sugar, organic acid, naringin, hesperidin and inorganic elements change of six varities of Cheju citrus fruits; Citrus natsudaidai, C. grandis, C. platymamma., C. sudachi, C. aurantiun and C. unshiu Marc. var. miyagawa by harvest date were investigated. Changes in free sugar of citrus fruits on the different harvesting stages and varieties showed a little differencies. The content of sucrose, glucose and maltose in citrus juice were $44.9{\sim}66.0%,\;15.7{\sim}25.7%\;and\;17.5{\sim}30.1%$, respectively. As the fruits were matured, free sugar was increased, but organic acid was decreased gradually. The major organic acids from the fruit juice were citric acid, malic acid and oxalic acid. Citric acid content exceeded 90%, oxalic acid ranged less than 3.58% and malic acid ranged $0.98{\sim}9.45%$ in total organic acids. Both naringin and hesperidin content showed markedly high in immature fruits, and in rind compare to fruit juice. Naringin and hesperidin content decreased as peel coloration progressed. It was estimated that fully matured fruits would be useful for making processed products, which lead to less turbity and less bitterness.

• Journal of the Korean Society of Food Science and Nutrition
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• v.5 no.1
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• pp.61-64
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• 1976

A survey of the free amino acids and organic acids in the shoot of Phyllostachys edulis was made by means of amino acid autoanalyzer and gas chromatograph. The results of the survey are summerized as follows. 1. Eighteen amino acids found in bamboo shoot were lysine, histidine, arginine, tryptophan, aspartic acid, glutamic acid, threonine, serine, proline, glycine, alanine, valine, leucine, isoleucine, methionine, tyrosine and phenylalanine, and an unknown was found. Serine showed the highest amount and more than about 44% of total free amino acids. 2. Oxalic acid was the major organic acid, and formic acid, acetic acid, maleic acid, succinic acid, fumaric acid, citric acid, tartaric acid and sorbic acid were determined, and two unknown were found.

• Korean Journal of Human Ecology
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• v.5 no.1
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• pp.94-106
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• 2002

The present study investigated free sugar, organic acid, volatile components in fresh leaf and root of the coriander respectively, and in blanched leaf and root of the coriander, respectively. The research results are as follows : Glucose, fructose and sucrose were detected in leaf and root of the coriander. The content of total free sugar was 22.91mg% in leaf and 23.84mg% in root. By blanching, the contents of total free sugar decreased to 21.28mg% and 21.89mg% in leaf and root respectively. Malic acid, trataric acid were detected in leaf and root of the coriander. The content of total organic acid in leaf was higher than that in root of the coriander. By blanching, the content of total organic acid significantly decreased in leaf and slightly decreased in root. A total of 98 flavor components were detected in the leaf of coriander and total contents of those were 878.485mg/kg. The major components were (E)-2-Decen-1-ol, (E)-2-Decenal, and (E)-2-Tetradecenal. And a large amount of aldehydes and alcohols were shown in the leaf of coriander. By blanching, a total of 75 flavor components were detected in the leaf of coriander and total contents of those were 846.49mg/kg. The major components were (E)-2-decenal, (E)-2-Tetradecenal, decanal. The amounts of aldehydes were increased more. However, the amounts of alcohols were decreased more than those of the fresh leaf, respectively. A total of 77 flavor components were detected in the root of coriander and total contents of those were 455.064mg/kg. The major components were (E)-2-Tetradecenal, (E)-2-Decenal, and (E)-2-Dodecenal. By blanching, the kinds and the contents of the flavor components decreased and the major components is the same of the fresh root. And the contents of aldehydes and alcohols, acids decreased. However, the contents of esters and ketons increased.

• Journal of Applied Biological Chemistry
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• v.64 no.2
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• pp.159-164
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• 2021

Heavy metals exist in soils in various chemical forms including free metal ions and organo-metal complexes. The ratio of free metal ions has been known to be highly associated with the plant absorption of heavy metals. This study aims to understand the effect of free ions and organo-metal complexes on the absorption of lead (Pb) and cadmium (Cd) by plants. For this, lettuce grown in a hydroponic system for 28 days was consequently grown another 48 hours using Pb and Cd solutions. The ratios of free ion to organo-metal complexes in the solutions were adjusted at 100:0, 90:10, 70:30, 60:40 by four different organic acids (citric, oxalic, acetic, and humic acid). After that, the concentration of Pb and Cd in lettuce were analyzed. The Pb and Cd absorption by lettuce was more relied on the types of organic acids treated and the type of metals rather than the ratio of free metal ions. For example, citric acid increased the Pb absorption while it decreased the Cd absorption by lettuce. There was no significant relationship between free metal ion ratios and both Pb and Cd uptake by lettuce. It could be explained that citric acid, a relatively higher molecular weight organic acid, has higher ion binding capacity, so it forms organo-Pb complex easily due to the higher affinity of Pb on the binding site in comparison with Cd. Consequently, this complexation would assist Pb uptake by lettuce.

• Journal of Sensor Science and Technology
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• v.26 no.3
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• pp.186-191
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• 2017

In this study, we investigated the simultaneous detection properties of organic vapor, pressure difference, and magnetic field using a single rugate-structured free-standing porous silicon (RFPS) thin film. Both the wavelength and the intensity of the rugate peaks were changed in the reflectivity spectrum measured at the thin film surface while the organic vapor was exposed to the RFPS thin film. However, when the pressure difference and the magnetic field were exposed to the film, only the rugate peak intensity was changed. Therefore, it is possible to distinguish whether or not the organic vapor is detected by simultaneously changing the rugate peak wavelength and intensity. In addition, a method of distinguishing between the pressure difference and the magnetic field detection signal has been derived by rapidly modulating the direction of the magnetic field. This study shows that it is possible to simultaneously detect and distinguish various objects using a single RFPS thin film, and it is found that porous silicon can be utilized as a sensor sufficiently.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.1
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• pp.42-47
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• 2002

The major free sugars of buckwheat plants were fructose, glucose, and maltose but their contents and compositions were influenced by the different wavelength of light. Free sugar contents of Clfa 39 (Fagopyrum tataricum) were higher than those of Yangjul-maemil (Fagopyrum esculentum) regardless of the light sources. As treated with red and blue light, the free sugar contents in the leaves of buckwheat plants were slightly increased, but their contents in the stems and flowers were lower than those of natural light condition. Under the natural light condition, maltose was detected in every tissues of buckwheat plants, but as treated with blue and red light, it was not detected in the flowers of buckwheat plants. Citric, malic and acetic acid were detected as major organic acids in buckwheat plants. Red and blue lights decreased the total organic acid contents in buckwheat plants as compared with natural light condition. It was considered that blue light are less active than red light for the accumulation of organic acids. Tataric acid was detected only in the leaves of buckwheat plants, however, as treated with red and blue light, it was not detected in the leaves of Clfa 39. Flowers of Yangjul-maemil contained a considerable amount of rutin and quercitrin. Only small amount of quercitrin was detected in leaves, but it was not detected in stems. On the other hand, Clfa 39 leaves contained a considerable amount of rutin, quercetin and small amount of quercitrin, but quercitrin and quercetin were detected only in the stems of Clfa 39. Red and blue lights significantly decreased the contents of rutin, quercitrin, and quercetin in buckwheat plants as comparing with natural light condition. Rutin content in the flowers of Clfa 39 was increased under the red and blue light conditions.

• ETRI Journal
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• v.27 no.3
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• pp.319-325
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• 2005

In this paper the effect of temperature on the electrical properties of organic semiconductor disperse orange dye 25 (OD) have been examined. Thin films of OD have been deposited on $In_{2}O_{3}$ substrates using a centrifugal machine. DC current-voltage (I-V) characteristics of the fabricated devices $(Al/OD/In_{2}O_{3)$ have been evaluated at varying temperatures ranging from 40 to $60^{\circ}C$. A rectification behavior in these devices has been observed such that the rectifying ratio increases as a function of temperature. I-V characteristics observed in $Al/OD/In_{2}O_{3)$ devices have been classified as low temperature $({\leq} 50^{\circ}C)$ and high temperature characteristics (approximately $60^{\circ}C$). Low temperature characteristics have been explained on the basis of the charge transport mechanism associated with free carriers available in OD, whereas high temperature characteristics have been explained on the basis of the trapped space-charge-limited current. Different electrical parameters such as traps factor, free carrier density, trapped carrier density, trap density of states, and effective mobility have been determined from the observed temperature dependent I-V characteristics. It has been shown that the traps factor, effective mobility, and free carrier density increase with increasing values of temperature, whilst no significant change has been observed in the trap density of states.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1714-1715
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• 2011

In this work, highly conductive organic solvent-based polyaniline(PANI) was used as an anode in organic photovoltaic cells (OPV) based on poly - (3-hexylthiophene) and [6,6] - phenyl - C60 - butyricacid methyl ester (P3HT : PCBM). The transmittance of the used PANI film were 87.67% and 86.57% at 550nm, and its sheet resistance were 454 ${\Omega}/{\Box}$ and 298 ${\Omega}/{\Box}$. We fabricated ITO-free OPV cells using PANI as an anode, which exhibited an external power conversion efficiency of 2.28% with a result of Jsc of 6.922mA/cm2, Voc of 0.6093V, and FF of 54.10% under an illumination of air mass(AM) 1.5G (100mW/$cm^2$). We used ink-jet printing to deposit buffer layer and active layer on a glass substrate.