• Applied Biological Chemistry
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• v.48 no.2
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• pp.132-139
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• 2005

The major obstacle in the popularization of Chungkookjang is the short shelf-life of $2{\sim}3$ months and some problems concerning storage including the growth of molds even in the products even within shelf-life. To solve these problems we conducted a research to improve its storage by using the vacuumed packaging and sanitary method through seed culture, innoculation and sterilization. For the optimization of storage time, temperature and sterilization temperature, we measured viable cell numbers of bacteria and fungi, amount of gas outbreak and contents of amino type nitrogen and monitored these experimental results by response surface methodology of SAS program, so that we could observe the quality changes of Chungkookjang during shelf-life. Especially fungi, which are the biggest troublemaker in Chungkookjang shelf-life, couldn't be detected from the generally and vacuum-packed samples; also, viable cell numbers were highly influenced by sterilization temperature and in vacuum-packed samples. In the case of vacuum-packed samples, amount of gas outbreak was highly influenced by sterilization temperature of its storage conditions and it was higher in generally packed samples as compared to vacuum-packed samples even at any storage conditions. The changes of pH in generally and vacuum-packed samples were highly influenced by the storage temperature. As the temperatures of storage and sterilization were higher and the storage time was longer, so the amount of gas outbreak was accordingly lower. These results showed that amino type nitrogen contents in generally and vacuum-packed samples were systematically influenced by the temperature, storage time and sterilization temperature. Also the result showed that the change of amino type nitrogen contents during storage was less in vacuum-packed samples than in general ones. Based on the above results, we can produce Chungkookjang products with extended shelf-life of as far as 6 months without any quality change using sanitary manufacturing method, vacuumed packaging condition, sterilization in $70^{\circ}C$ for 60 minutes and storage under $10^{\circ}C$ during shelf-life. According to this research, we have the possibility to greatly increase the goods value of Chungkookjang by developing the manufacture processing and packaging.

• Food Science of Animal Resources
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• v.28 no.1
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• pp.69-75
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• 2008

This study evaluated the physicochemical and sensory characteristics of vanilla ice cream treated with gamma irradiation. The general composition of the vanilla ice cream used for the study was 45.4-53.3% moisture, 5.5-5.9% fat and 3.9-4.1% protein, and these values did not change following gamma irradiation. The Hunter L, a and b values were slightly decreased following gamma irradiation. The fatty acid composition of the ice cream included caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid and stearic acid, and there was no detectable change following irradiation. There was no significant difference in TBARS (2-thiobarbituric acid reactive substances) values between non-irradiated and irradiated samples at a dose of 3 kGy or less (p<0.05). Sensory evaluation indicated that gamma-irradiated vanilla ice cream did not show any difference in color relative to non-irradiated ice cream. However, gamma irradiation did affect the flavor, taste and overall acceptability of ice cream at doses above 3 kGy. These results indicate that gamma irradiation at 3 kGy is an effective treatment for sustaining the physicochemical characteristics of vanilla ice cream with minimal changes in sensory characteristics, though further studies should be carried out to reduce the deterioration of sensory qualities induced by gamma irradiation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.6
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• pp.924-932
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• 2013

This study investigated the antioxidant activities of processed Deoduck (Codonopsis lanceolata) extracts treated through high-pressure extraction and steaming with fermentation. The antioxidant activities were determined for DPPH and ABTS radical-scavenging activity, SOD-like activity, ferric reducing antioxidant power (FRAP), and $Fe^{2+}$ chelating. Total phenolic and flavonoid contents were also measured. Among eight Deoduck extracts, the S5FDW extract had the highest total phenolic and flavonoid content, 73.9 mg GAE/g and 50.9 mg QUE/g, respectively. The S5FDW extract had the highest DPPH radical-scavenging activity (27%) at a 1.0 mg/mL concentration. The ABTS radical-scavenging activity was highest for S5FDW extract (82.1%) at a 10 mg/mL concentration. The HFDE extract showed the highest SOD-like activity (29.7%) at a 1.0 mg/mL concentration. FRAP was highest in S5FDW extract (140.8 ${\mu}M$) at a 1.0 mg/mL concentration. The DE extract showed the highest $Fe^{2+}$ chelating (46%) at a 1.0 mg/mL concentration. The phenolic and flavonoid contents significantly correlated with the antioxidant activity of several processed Deoduck extracts and was higher in the processed Deoduck extracts compared to the raw Deoduck extracts. Therefore, processing techniques can be useful methods for making Deoduck a more potent and natural antioxidant.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.5
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• pp.293-303
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• 2004

This experiment was conducted to investigate the direction or orientation of clay particle movement in argillic horizons (Bt) for clarifying the soil classification of soils. Soil samples were collected from 22 soil series containing Bt horizons. Physical and chemical characteristics and mineral and chemical compositions of clay in the soils were analyzed. Micoromorphological characteristics of the Bt horizons were also investigated with thin sections of the natural undisturbed and oriented soil samples. Average clay content in the Bt horizons was 28% and 1.33 times higher comparing to that in the surface layer. Soil pH was higher, but cation exchange capacity (CEC) and organic matter content were lower in Bt horizon than those in the surface layer. There was an evidence of clay accumulation in Bt horizons of all soil series examined except Bangog series. Although there was an increase of clay content in the horizons in Bangog series, the clay was not originated from illuviation process. The translocation of clay was in the order of an 2:1 expandable clay minerals > 2:1 non-expandable clay minerals > 1:1 clay minerals. The illuvial substances in argillic horizon were composed with clay, amorphous iron and opaque mineral. The micoromorphological features of Bt horizon were void coating, channel infilling and grain coating. There was an apparent boundary between clay coating and the groundmass in residuum and colluvium, but Bt horizon of alluvium was composed of a skew plane amputated by the physical operation.

• Applied Chemistry for Engineering
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• v.24 no.2
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• pp.184-189
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• 2013

In the present study, batch experiments were carried out for the utilizatioin of activated carbon as a potential adsorbent to remove a hazardous malachite green from an aqueous solution. The effects of various parameters such as temperature, contact time, initial concentration on the adsorption system were investigated. On the basis of adsorption data Langmuir and Freundlich adsorption isotherm model were also confirmed. The equilibrium process was described well by Langmuir isotherm model. From determined separation factor, the activated carbon could be employed as an effective treatment for removal of malachite green. From kinetic experiments, the adsorption process followed the pseudo second order model, and the adsorption rate constant ($k_2$) decreased with increasing both the initial concentration of malachite green and the adsoprtion temperature. Thermodynamic parameters like that activation energy, change of free energy, enthalpy, and entropy were also calculated to predict the adsorption nature. The activation energy calculated from Arrhenius equation indicated that the adsortpion of malachite green on the zeolite was physical process. The negative Gibbs free energy change ($\Delta$G = -3.68~-7.76 kJ/mol) and the positive enthalpy change ($\Delta$H = +26.34 kJ/mol) indicated the spontaneous and endothermic nature of the adsorption in the temperature range of 298~318 K.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.3
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• pp.110-116
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• 2016

Biogas yields point of view, the possibility of reusing excess sludge treated by thermal pretreatment for the purpose of improving the efficiency of the anaerobic digestion process has been investigated in recent year. Thermal pretreatment technology was considered as a pretreatment technique to improve excess sludge properties because of the solubilization of particulate organics. As a view point of sludge reduction and recycle, however, many researchers focused on the ability of particulate hydrolysis and COD solubilization under a high temperature, and few reports have addressed on the physical/chemical characteristics changing. This research was performed to evaluate the effects of a various temperature and chemical additives on carbon formation and fractionation in treated slurry from thermal pretreatment. Based on the results, it was revealed that oxidants injection and temperature changing have significantly caused the change of carbon fractions in slurry from thermal pretreament. Especially, it was considered that the efficiencies of particle hydrolysis increased with the increase of the reaction temperature. Low molecular weight(Mw < 350 g/mol) organic carbon formation increased with the increase of oxidants injection. It was expected that results of this research will provide an overview of the characteristics of thermal pretreatement for excess sludge reduction and recycle.

• Journal of Environmental Impact Assessment
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• v.29 no.4
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• pp.252-271
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• 2020

In this study, we investigated physical and chemical properties such as grain size, heavy metal pollution, magnetic properties, and their environmental impacts of road dusts (RD) collected from 14 sampling points in Daebul industrial Complex. Heavy metal concentrations in RD were in the order of Fe>Zn>Cu>Pb>Cr>Ni>As>Cd>Hg, and this pollution pattern was related to major industries and traffic activities in this area. The results of the correlation analysis between heavy metal elements and particle size in RD showed that Fe and all of analyzed heavy metals had a significant correlation with each other and metal concentrations had a significantly negative correlation (p<0.05). However, due to the input of large metal particles some heavy metal concentrations in the particle fraction of >1000 ㎛ were highest. Pollution load per unit area of this fraction was the highest among the grain size fractions. Cr, Ni, Cu, Zn, Cd, Pb levels in RD decreased and the levels of Cr, Ni, Cu, Zn, Cd, and Pb were reduced to 85 (As) -22 (Ni)% of the whole after removal of MFs fraction from RD. The mean heavy metal levels in the study area did not exceed the soil contamination guide value of Korea, indicating that heavy metal levels in RD were not a concern. However, at some sampling points, Zn concentrations were exceeded the soil contamination guide value for the 3rd areas of Korea and this result indicated that further studies of the impact of RD on the surrounding environment through re-suspension or non-point pollution, and of effective management methods are required.

• Journal of the Korean Society of Tobacco Science
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• v.31 no.2
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• pp.69-74
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• 2009

Potato Virus Y (PVY), PVY-vein necrosis strain, causes severe damage at growth, yield and leaf quality on flue-cured tobacco in Korea. The development of PVY resistant flue-cured varieties without quality deterioration is therefore urgently desired. The flue-cured tobacco, KF120 (Korea Flue-cured 120), was a male-sterile (ms) $F_1$ hybrid derived from the cross between msKF117 and KF0007-7. msKF117 was developed from the cross of NC82 with N. africana and KF0007-7 was developed from the cross of KF117 with NC82. The agronomic characteristics and disease resistance of KF120 was evaluated during 2006-2007 field performance test. It showed better growth characteristics and yield performance than standard cultivar KF109. It had 2 more leaves per plant, flowered 2 days later than KF109. The yield of cured leaf of KF120 was increased by about 5% compared to KF109. The chemical composition and physical properties of the cured leaf of KF120 were as much acceptable as those of KF109. KF120 showed high resistance to PVY compared to KF109. It showed a similar mode of resistance to bacterial wilt and black shank as was found in KF109.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.2
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• pp.207-214
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• 1996

This study was conducted to obtain fundamental information on forage sorghum breeding in forage crop field of Livestock Experiment Station at Suwon from 1986 to 1991. The charcterization of sorghum germplasm was performed through 1986 to 1987, and after parental lines were selected from diverse sorghum germplasm on the basis of flowering date, plant height and several morphological characters for forage sorghum Fl hybrids. The range of variation of 50% flowering date and plant height were greater in order of forage sorghum sudangrass and male sterile line of grain sorghum. The average flowering date was earlier in sudangrass and male sterile line of grain sorghum than forage sorghum lines from the tested sorghum germplasms. And the average plant height was tall in order of forage sorghum, sudangrass and male sterile lines of grain sorghum. There were remarkable morphological variations between sudangrass lines and male sterile lines of grain sorghum such as plant color, leaf midrib color, glume color, seed coat color, head compactness and shape, awns, grain covering and 100 seed weight.

• Clean Technology
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• v.13 no.1 s.36
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• pp.54-63
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• 2007

Even traces of CO in the hydrogen-rich feed gas to proton exchange membrane fuel cells (PEMFC) poison the platinum anode electrode and dramatically decrease the power output. In this work, a variety of catalytic materials consisting of $Cu/Ce_xZr_{1-x}O_2$, (x = 0.0-1.0) were synthesised, characterized and tested for CO oxidation and preferential oxidation of CO (PROX). These catalysts prepared by hydrothermal and deposition-precipitation methods. The catalysts were characterized by XRD, XRF, SEM, BET, $N_2O$ titration and oxygen storage capacity (OSC) measurement. The effects of composition of the support and degree of excess oxygen were investigated fur activity and $CO_2$ selectivity with different temperatures. The composition of the support markedly influenced the PROX activity. Among the various $Cu/Ce_xZr_{1-x}O_2$ catalysts having different composition, $Cu/Ce_{0.9}Zr_{0.1}O_2$ and $Cu/Ce_{0.7}Zr_{0.3}O_2$ showed the highest activities (>99%) and selectivities (ca.50%) in the temperature range of $150{\sim}160^{\circ}C$. It was found that by using of $Ce_xZr_{1-x}O_2$ mixed oxide support which possesses a high oxygen storage capacity, oxidation-reduction activity of Cu-based catalyst was improved, which resulted in the increase of catalytic activity and selectivity of CO oxidation in excess $H_2$ environments.