• Applied Biological Chemistry
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• v.40 no.3
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• pp.209-214
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• 1997

The canned fruit flesh of orange (Onju, Citrus unshi Marc.) was stored at $5^{\circ}C,\;15^{\circ}C,\;and{\;}30^{\circ}C$ for 4 months and the contents of sugar, organic acids and vitamin C of stored orange were investigated. The contents of reducing sugar of orange stored for 4 months slightly increased from 4.91% to $5.39{\sim}7.95%$ and decreased as the temperature rised. The sugar was composed of $6.63{\sim}18.09%$ sucrose, $3.86{\sim}9.12%$ glucose and $3.59{\sim}9.51%$ fructose. The content of sucrose used in manufacturing process was the highest and decreased as the temperature rised and as the storage period prolonged, whereas the contents of glucose and fructose increased as the storage period prolonged. The content of citric acid in the sample was the highest $(50.41{\sim}90.15\;mg%)$ among the-citric, malic, maleic, ${\alpha}-ketoglutaric$ and oxalic acids. The organic acids decreased as the temperature rised after storage for 4 months. The content of vitamin C was $8.28{\sim}14.29\;mg%$ and decreased most pronouncedly at $30^{\circ}C$ after storage. The color of the samples did not change significantly, but the degree of transparency, L was $20.41{\sim}23.01$ after storing the sample.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.6
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• pp.313-320
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• 2005

Various by-product composts are applied in alpine farmland, and some of them generate many problems especially when they are not completely composted. The objective of this study was to investigate the physicochemical and spectroscopic properties of by-product composts used in Gangweon alpine uplands. Average organic matter content, C/N ratio and NaCl content in 3 species of registered composts were 33%, 13 and 0.8%, respectively, and the general quality were better than the guideline of by-product compost. Odor and contents of $NH_3$ and $CO_2$ in the registered composts were relatively lower than those in the unregistered composts. Among the 13 unregistered composts tested in this experiment, 3 species contained organic matter content less than 25%, 5 species had C/N ratio less than 10, and 8 species contained NaCl exceeded the acceptable level. Eight species in the unregistered composts contained more than 50% of water. Contents of heavy metals in both the registered and unregistered composts were lower than the acceptable level. In spectroscopic property analysis, registered composts were Band P types, and unregistered composts were Rp and P types.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.4
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• pp.365-372
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• 2006

A dynamic compartment model is presented to predict the contamination level of agricultural plant by $^{137}C_s$ as a result of a soil deposition. The model considered the processes of a percolation, soil mixing by a plowing before transplanting, plant uptake, leaching to a deep soil, and fixation to a clay mineral. The effects of the soil properties (pH, clay mineral, organic matter content, and exchangeable K), which are spatially varied, on a plant uptake and the leaching rates of $^{137}C_s$ in a root zone soil were modeled by the Absalom model. To test the validity of the model, the $^{137}C_s$ aggregated transfer factors(TFa) for rice plants were compared with those observed from some simulated $^{137}C_s$ soil deposition experiments, which were carried out with respect to rice plants cultivated in seventeen paddy soils of different properties for two consecutive years. Observed $^{137}C_s$ TFa values of the rice plants did not show an evident trend for the pH and clay content of the soil properties, while they increased with an increasing organic matter content or a decreasing exchangeable K concentration. Predicted $^{137}C_s$ TFa values of the rice plants were found to be comparable with those observed.

• Applied Chemistry for Engineering
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• v.19 no.2
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• pp.185-190
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• 2008

In order to increase the surface area of electrodes for electrosorption, porous carbon electrodes were fabricated by a wet phase inversion method. A carbon slurry consisting of a mixture of activated carbon powder (ACP), polyvinylidene fluoride (PVdF), and N-methyl-2-pyrrolidone (NMP) as a solvent was cast directly on a graphite sheet. The cast film was then immersed in pure water for phase inversion. The physical and electrochemical properties of the electrodes were investigated using scanning electron microscopy (SEM), porosimetry, and cyclic voltammetry. The SEM images verified that the pores of various sizes were formed uniformly on the electrode surface. The average pore sizes determined for the electrodes fabricated with various NMP contents ranged from 64.2 to 82.4 nm and the size increased as the NMP content increased. All of the voltammograms showed a typical behavior of charging and discharging characteristic at the electric double layer. The electrical capacitance ranged from 3.88 to $5.87F/cm^2$ depending on the NMP contents, and the electrical capacitance increased as the solvent content decreased. The experimental results showed that the solvent content is an important variable controlling pore size and ultimately the capacitance of the electrode.

• Korean Journal of Food Science and Technology
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• v.33 no.2
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• pp.256-263
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• 2001

Physicochemical characteristics of kochujang prepared with meju, koji and mixture of meju and koji were analyzed during fermentation in order to improve quality of traditional sikhe kochujang. Amino nitrogen content, an index of kochujang quality, was remarkably higher in kochujang prepared with p-2 koji, p-1 koji, mixture of p-2 koji and meju. Titratible acidity of kochujang slightly increased and pH of kochujang increased until 40 days of fermentation and then decreased there after. Citric acid was found as a major organic acid followed in decreasing order by malic, oxalic, succinic, acetic and lactic acids. As a free sugar, maltose, glucose and fructose were detected. Free sugar content was higher in kochujang prepared with p-1 koji than the others. The major free amino acids were aspartic acid, glutamic acid, alanine, phenylalanine and arginine, and total free amino acid content was higher in kochujang prepared with koji, and mixture of meju and koji than the one with traditional meju only. In sensory evaluation, all tested groups did not show a significant difference. This result indicates that addition of koji to sikhe kochujang influences on taste components like free sugars and free amino acids, but decisively not on the sensory properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1271-1278
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• 2011

This study was carried out to investigate the food components of the fruit, cladodes, and flowers of freezedried Cheonnyuncho harvested from Yeosu, Jeonnam in Korea. The major components of freeze-dried Cheonnyuncho in proximate composition were carbohydrates and crude ash. Ca, K, and Mg were the predominant minerals in Cheonnyuncho. Calcium content was higher in the fruit and cladodes than in the flowers. Two major amino acids, glutamic acid and aspartic acid, made up over 25% of the total amino acids in Cheonnyuncho. Palmitic acid and stearic acid were most abundant out of all the saturated fatty acids in Cheonnyuncho. The saturated fatty acid content of the fruit was higher than that of the flowers and cladodes. The major unsaturated fatty acid of Cheonnyuncho was oleic acid. The cladodes contained unusually high amounts of linoleic acid compared to the fruit and flowers. The major free sugar in the fruit was sucrose, whereas that of the cladodes and flowers was fructose. The total free sugar content was the highest in fruit, followed by cladodes. The most abundant organic acid in the fruits and cladodes was malic acid, while that of the flowers was citric acid. Vitamin A concentration was highest in the flowers whereas vitamin C concentration was highest in the fruit.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.4
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• pp.526-532
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• 2012

This study was conducted to investigate chemical properties of wild $Lactuca$ $indica$ (WL) and cultivated $Lactuca$ $indica$ (CL). The proximate composition, reducing sugar, free amino acids, organic acid, vitamin C, minerals, chlorophyll, and crude saponin were analyzed. WL and CL contained high levels of carbohydrate. The leaves and roots of CL contained higher levels of free amino acid than those of WL. Especially, the proline content of CL leaf was 12 times higher than that of WL leaf, and the arginine content of CL root was 100 times higher than that of WL root. The major organic acid and mineral of $Lactuca$ $indica$ were tartaric acid and potassium, respectively. CL showed significantly higher value of reducing sugar than WL. The vitamin C content of the samples ranged from 0.4 to 24.1 mg%, and CL leaf was the highest amount of vitamin C among the samples. CL leaf had a higher amount of chlorophyll than WL leaf, but WL root contained a higher amount of crude saponin than CL root. As in this study, CL showed better nutritional properties than WL, and these results will provide fundamental data in order to activate the cultivation of wild plants.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.63-71
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• 2009

In order to improve flame retardancy, the halogen free organic melamine phosphate(M-P) flame retardant was synthesized from melamine and phosphoric acid by the reaction of precipitation. The ignition test was carried out preparing hybrid flame retardant compound($H_bFRC$) consisting of organic M-P and inorganic Mg$(OH)_2$ as a flame retardant in the polyolefin resins. The flame retardancy and mechanical properties of flame retardant aluminum composite panel($H_bFRC$-ACP) were performed to investigate the possibility of the composite material, which was contained M-P, as a inner core for $H_bFRC$-ACP. For this study, the results of ignition test indicate that a char formation and drip suppressing effect, and combustion time reduced as the content of M-P increased. The limited oxygen index(LOI) values were measured 17.4vol% and 31.5vol% for LDPE only and $H_bFRC$-3(M-P content: 15wt%), respectively. And it was verified that the $H_bFRC$-3 was needed more oxygen quantity with the increase of M-P content when it combustion. Also, the results from thermogravimetric analysis were observed endothermic peak at $350^{\circ}C$ and $550^{\circ}C$, it was confirmed predominant thermal stability though the wide temperature range by the mixture of M-P and Mg$(OH)_2$. The LDPE-ACP (using only LDPE as a inner core), $35.13kW/m^2$ of heat release rate(HRR) and 13.43MJ/m2 of total heat release(THR) were measured while the $H_bFRC$-ACP, $10.44kW/m^2$ of HRR and 1.84MJ/m2 of THR were measured by results of cone calorimeter test. In case of $H_bFRC$-ACP, the average gas emission amount of CO and $CO_2$ could be decreased down to 25% and 20%, respectively, in comparison with LDPE-ACP. The mechanical properties such as tensile strength, bending strength and adhesion strength of $H_bFRC$-ACP were revealed slightly high values $54N/mm^2$, $152N/mm^2$ and 120N/25mm, respectively, compared with LDPE-ACP. It was confirmed that flame retardancy was improved with the synergy effect because of char formation by M-P and hydrolysis by Mg$(OH)_2$. The result of this study suggest that $H_bFRC$ can be applied for an adequate halogen free flame retardant composite material as a inner core for ACP.

• KSBB Journal
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• v.22 no.2
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• pp.102-108
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• 2007

A sewage was treated using a vertical flow zeolite-filled reed bed. The sewage from the student dormitory of Changwon National University was fed into the reed bed for 10 minutes every 6 hours at the hydraulic load of $314L/m^3{\cdot}$day. The filtering height of the reed bed was 100 em and the zeolite mixture was filled in the reed bed. The mixture consisted of the same volume of two types of zeolite: 0.5$\sim$1 mm and 1$\sim$3 mm in diameter. Annual average removal efficiency was 88 89.9%, $COD_{Cr}$ 86.1 %, $COD_{Mn}$ 81.2%, T-N 34.0%, $NH_4^+$-N 97.3% and T-P 34.6%. T-N of effluent was mostly $NO_3^-$-N and the concentration of $NO_2^-$-N in effluent was lower than 0.1 mg/L. All removal efficiencies did not show a remarkable seasonal change. The ranking of phosphorous fractions fixed to the zeolite in column test was Ca-P > Fe-P > reductant soluble Fe-P > occluded P > saloid P > AI-P at all depths of the filter. All phosphorous fractions except for AI-P reduced at deeper filter layer, while their content ratios increased at deeper filter layer. Organic matter content was the highest at the highest layer (0$\sim$5 cm from the top of the filter) and only small differences were observed at the deeper filter layer than 5 em from the top. Organic matter content increased at all depths of the filter with the operating time.

• Korean Journal of Environment and Ecology
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• v.27 no.4
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• pp.498-506
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• 2013

In order to identify soil characteristics and to estimate the age of wetland, soil samples of Mt. Sohwangbyoung wetland and Jilmoi wetland known as peatland in Odaesan National Park.were collected and analyzed. Soil pH of Mt. Sohwangbyoung wetland and Jilmoi wetland showed average pH of 5.5, and did now show any significant difference according to the time and plant community. Total ionic content of soil showed different values among plant communities, but no difference by time in each plant community. Soil exchangeable cations such as Na, K and Mg showed a similar pattern of total ionic content. Unlike other cations, however, Ca content showed significant differences according to the plant community and time. Soil organic matter and total nitrogen contents showed remarkable differences according to plant community, and especially showed very low valeus at the place where Sphagnum palustre distributes. Based on the results of the above, Mt. Sohwangbyoung wetland and Jilmoi wetland can be considered as weakly acidic bog. From age analysis, two wetlands are estimated to have been formed before 100 AD for Mt. Sohwangbyoung wetland and 1448 AD for Jilmoi wetland, respectively.