• The Korean Journal of Food And Nutrition
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• v.10 no.3
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• pp.295-301
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• 1997

Among 120 microorganisms isolated from soil, KF-67 was the best producer of flocculant and was examined for flocculating ability in the kaolin clay and CaCl2 suspension. KF-67 was identified to be a species belong to the genus Agrobacterium sp. The influence of components of the culture medium for flocculant production by Agrobacterium sp. KF-67 was studied. The favorable carbon and inorganic nitrogen source for production of the flocculant were glucose and NH4NO3 and their addition concentrations were 2% and 0.1%, respectively. Addition of the organic nitrogen such as yeast extract, peptone and inorganic salt such as CaCO3 significantly increased the production of flocculant. These result indicated that the production of flocculant by Agrobacterium sp. was significantly affected by both organic nitrogen and inorganic salt. The components of the optimum culture medium were 2% glucose, 0.1% NH4NO3, 0.01% yeast extract, 0.01% peptone, 0.04% CaCO3, 0.03% NaCl in initial pH 7.5 when cultured with rotary shaker controlled at 3$0^{\circ}C$ and 120 rpm. Under the optimum culture medium, flocculant production was highly improved about 76% than that isolation medium.

• YAKHAK HOEJI
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• v.36 no.3
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• pp.278-284
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• 1992

This study was performed to investigate the effects of ginseng saponins on the cerebral energy metabolite's contents influenced by carbon monoxide(CO) intoxication. Each experimental group was divided young ($5{\sim}8$ weeks) and aged ($43{\sim}52$ weeks) rats, and they were exposed at 5,000 ppm CO (72%HbCO) for 30 min. One of the other groups was pretreated with ginseng saponins for 5 days before CO intoxication. The contents of cerebral energy metabolites in cerebral cortex, stratum and hypothalamus were measured. In cerebral cortex of both young and aged rats, the levels of ATP and creatine phosphate were significantly decreased, while those of lactate were significantly increased. There was no difference between the levels of cerebral energy metabolites of young and aged rats. Pretreatment of ginseng saponins before CO intoxication lowered decrease of the levels of cerebral energy metabolites and ATP levels were significantly recovered. On the other hands, contents of lactate in stratum and hypothalamus of young rats were significantly increased and the levels of ATP and creatine phosphate in stratum and hypothalamus were completely recovered at 2 weeks after CO intoxication. The results suggest that ginseng saponins have an ameliorating action against disturbance of the cerebral energy metabolites by CO intoxication.

• Journal of the Korean Vacuum Society
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• v.6 no.2
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• pp.151-158
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• 1997

Nitrogen incorporated diamond-like carbon films were deposited by r.f. glow discharge of mixtures of benzene and ammonia gases. Mechanical properties, composition and atomic bond structure were investigated when the fraction of ammonia increases from 0 to 0.79 and the negative self bias voltage of cathode from 100 to 900 V. Both the residual compressive stress and the hardness decrease from 1.7 to 1.0 GPa and from 2750Kgf/$\textrm{mm}^2$ to 1700Kgf/$\textrm{mm}^2$, respectively. In addition to hydrogen, triply bonded nitrogens also play a role of teminal sites of the three dimensional atomic bond network. By considering the hydrogen concentration and the nitrogen bond characteristics, it can be shown that the mechanical properties of the films are determined by the content of three dimensional inter-links of $sp^2$ clusters. Although the mechanical properties are affected by the nitrogen addition, its depedence on the negative bias voltage is qualitatively identical to that of pure diamond-like carbon films.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.6
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• pp.801-805
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• 2003

Volatile flavor components in chestnut (Castanea crenate Sieb. et Zucc.) flower were collected by SDE method using the mixture of n-pentane and diethylether as an extract solvent and were identified by GC-FID and GC/MS. A total of 122 components including 35 alcohols,5 hydrocarbons,20 terpene and derivatives,7 ketones, 24 aldehydes, 12 esters, 4 acids, 3 furans, and 2 miscellaneous were identified from total volatile extract of chestnut. Alcohols were comprise 36.58% of volatile extract and dominant constituents and the main components of flower volatiles were 1-phenylethanol (18.6%), (E)-geraniol, tricosane, heneicosane, benzyl alcohol, acetophenone and 2-phenylethanol as aromatic alcohols and odd carbon hydrocarbons. Especially 1-phenylethanol and acetophenone would be applicable to the markers to ascertain floral origin of chestnut honey. The powerful animal and floral notes of chestnut flower were characterized by compounds including nonanal.

• Resources Recycling
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• v.9 no.2
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• pp.33-39
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• 2000

Low density ceramic supporter was prepared by using fly ash as a starting material for the application to the biological aerated filter system. Wheat powders were used to control the porosity of the supporter and the carbon content of the raw material. Apparent density of 1.6~1.8 g/$\textrm{cm}^3$ was obtained when the fly ash was sintered at $1200^{\circ}C$ in a weak reducing atmosphere. By maintaining the reducing atmosphere and sintering at a high heating rate, the liquid phase was formed from the reduced composition of fly ash. This resulted in the closed pore formation which enabled the low apparent density.

• Journal of the Korea Organic Resources Recycling Association
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• v.3 no.1
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• pp.61-71
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• 1995

This study is concerned with the assessment of the possibility of alum sludge composting, as well as changes of some chemical properties during composting. Alum sludge was mixed in different proportions, which are 0%, 25%, 35% and 45%, respectively, with a sewage sludge and sawdust mixture. The final mixtures to be composted are placed on static piles constructed with a perforated aeration pipe on the ground, and composted for more than 50 days. During the composting of some alum sludge treatments, there was not notable difference in changes of pH, C/N ratio, and content of several minerals among the alum sludge treatments, while changes of pile temperatures and CEC were significant and these remarkable differences in related to the pile temperatures and CEC seem suitable for the evaluation of alum sludge maturity. Also, the results suggested that the proper mixing ratio of alum sludge for composting was 25% level.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.1
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• pp.64-74
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• 2017

In this study, we have analyzed relationship between the measured Water Soluble Organic Carbon (WSOC) concentrations and the estimated aerosol water content of $PM_{10}$ (particulate matter with an aerodynamic diameter of less than or equal to $10{\mu}m$) for the period between September 2006 and August 2007 at Seoul, Korea. Water content of $PM_{10}$ was estimated by using a gas/particle equilibrium model, Simulating composition of Atmospheric Particles at Equilibrium 2 (SCAPE2). The WSOC concentrations showed low correlation with Elemental Carbon (EC), but Water Insoluble Organic Carbon (WISOC) were highly correlated with EC. It seemed that hydrophilic groups were produced by secondary formation rather than primary formation. As with the previous studies, WSOC showed good correlation with secondary ions ($NO_3{^-}$, $SO_4{^{2-}}$, $NH_4{^+}$), especially WSOC was highly correlated with $NO_3{^-}$ that is a secondary ion formed by photochemical oxidation from more local sources than $SO_4{^{2-}}$. No apparent correlation between the measured WSOC and estimated water content was observed. However, WSOC showed good correlation with estimated water content when it was assumed that relative humidity was higher than the deliquescence relative humidity of the system. In conclusion, WSOC is correlated with water content by hygroscopic ions and it is expected that nitrate play an important role among the water content and WSOC.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.300-300
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• 2009

화학비료를 이용할 수 없는 유기농업에서의 양분관리를 위해서 녹비, 퇴비, 유박 등을 주 원료로 하는 유기질비료 등 다양한 유기물이 농경지에 투입되고 있다. 그러나 다양한 성분 및 탄소/질소비로 이루어진 유기물은 토양 중에서 분해되는 속도가 다르고, 토양수분함량, 통기성, 온도 등과 같은 토양조건에 따라서도 분해속도가 크게 차이가 난다. 본 실험에서는 유기농업에서 시비원으로 자주 이용하는 퇴비, 유박비료, 녹비조건의 알팔파 등을 이용하여 무기화율 및 양분이용률을 화학비료와 비교하였다. 농경지 투입시 유기물은 질소양분양(21kg N/10a)을 동일하게 투입하였으며 화학비료는 기비(전체량의 1/3)만을 투입하였는데 알팔파, 유박비료의 경우 노지조건에서 토양처리 후 1달 내에 가장 높은 무기화율을 보였으며 수분조건이 제한된 무기화통내에서의 무기화도 2개월 내에 대부분 이루어지는 것으로 나타났다. 수딘그라스를 2개월 재배한 결과 화학비료 질소 양분이용율은 70%, 탄질비가 낮은 유박 및 알팔파는 40%내외, 탄질비가 높고 분해가 어려운 가축분 왕겨퇴비는 10%에 불과했다. 즉 화학비료 대비 유기물 양분(질소)의 비효화 율은 알팔파는 60%, 유박비료는 54%, 퇴비는 14% 였다. 또한 화학비료(100%) 대비 인산 이용률(유박: 296%, 알팔파: 660%, 퇴비: 36%로, 인산의 이용율이 높은 것은 유기물로 투입된 인산의 량이 화학비료보다 낮아 상대적으로 유기물질에 의한 작물의 인산이용율이 높고, 화학비료는 토양중 고정화가 작물생육 초기에 일어나는데 비하여 유기물질은 서서히 분해되면서 작물에 흡수되어 인산이용율이 높은 것으로 추정된다. 수단그라스 1차수확 후 포장침수로 인한 생육불량으로 전 생육 과정을 통한 양분흡수율은 측정할 수 없었다.

• Applied Biological Chemistry
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• v.44 no.4
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• pp.251-256
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• 2001

To develop biofertilizer solubilizing inorganic phosphate, a bacterium having high abilities to solubilize inorganic phosphate were isolated from cultivated soils. The strain was identified to Aeromonas hydrophila DA57, based on the physiological and biochemical properties. The optimum temperature and initial pH to solubilize insoluvle phosphate in sucrose minimal medium were $30^{\circ}C$ and pH 7.0, respectively. In these conditions phosphate solubilizing activities of the strain against three types of insoluble phosphate were quantitatively determined. It was possivle to distinguish between solubilization through release of gluconic acid and still unknown mechanism. Aemmonas hydrophila DA57 harbored a 4.5 kb cryptic plasmid.

• Korean Journal of Medicinal Crop Science
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• v.10 no.2
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• pp.88-92
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• 2002

The production of anthraquinone has been dectected in transformed roots of Rheum undulatum L. The effects of medium, initial pH, concentration of sucrose, light irradiation and elicitors on anthraquinone production in transformed roots of Rheum undulatum L. were investigated. The maximum production of anthaquinone was achieved in WPM medium (pH 5.7) supplemented with 6% sucrose, 0.5 mg/l $GA_3$, and 50 mg/l chitosan at 16h light $(16{\mu}mol\;m^{-2}s^{-1})$ condition. Under the optimum conditions, the production of anthraquinone reached to 0.18 mg/g(F.W.) after 8 weeks. The content was estimated about 1.3 times of the level of native roots.