• Applied Biological Chemistry
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• v.35 no.5
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• pp.382-388
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• 1992

Mycelial growth inhibition activity of forty-one N-substituted phenyl 5-chloro-1,3-dimethylpyrazole-4-carboxamides against Rhizoctonia solani was analysed quantitatively by multiple regression analysis using physicochemical parameters of substituents as independent variables and $pEC_{50}$ as dependent variable. As a result, a quantitative structure-activity relationship was formulated using eight physicochemical parameters, which explains 83% of variance of the fungicidal activity. The most important parameter for the biological activity was log k', as related to the penetration and transport processes in the biological system. The activity also correlated with other hydrophobic parameters$({\pi}_2,\;{\pi}_3)$, an electronic parameter$({\Sigma}{\sigma})$, and steric parameters$(STERIMOL\;parameters\;L_3,\;L_4)$.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.275-280
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• 2007

The effect of using Korean wheat flour versus Australian wheat flour on noodle quality as a result of differing physical and chemical properties of the flours was investigated. The results provided appropriate technical information for selection of wheat varieties to produce high quality Korean salted noodles. Noodle quality was quantified based on measurement of the appearance and texture of noodles. When consumer preference tests were conducted, a firmer and more elastic texture was preferred for Korean white salted noodles, however, when appearance was included in the consumer tests, noodles made with Australian wheat were favored over Korean wheats. Korean flour was found to produce firmer and more elastic noodles, whereas Australian flour produced brighter, creamier colored noodles. In flour quality tests, Korean flours were found to have a higher setback viscosity and lower swelling power than Australian flour. Additionally, Korean flours had higher water absorption values. Protein content of flour was an important parameter affecting the firmness of Korean noodles, whereas setback viscosity and swelling power were the major determinants of elasticity. Overall, the important parameters for determination of the quality of Korean salted noodles were high setback viscosity, low swelling power, and high protein content.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.850-854
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• 2012

This study is carried out in order to develop food materials for the promotion of rice consumption. In this study, we researched the physicochemical properties of extruded rice flour (ER) and gelatinization popped rice flour (GPR) by the extrusion process and by the popped method with milled rice and brown rice. The extrusion process used a couple of screw extruders. The extrusion parameter was kept constant at a feed moisture content of 25%, barrel temperature of $120^{\circ}C$ and screw speed of 400 rpm. GPR was prepared by batch popping machine after gelatinization of rice. In order to evaluate the physicochemical properties of ER and GPR, as well as the gelatinization rate, water soluble index (WSI), water adsorption index (WAI), DPPH radical scavenging activity and total dietary fiber content, the color value was carried out. The gelatinization rate was similar to 71.1~73.8%. Further, the results of WSI and WAI were increased at ER and GPR compared to the raw materials; ER was also higher than GPR. DPPH radical scavenging activity and total dietary fiber content showed a tendency to reduce after extrution and popping. As a result of the color value, the L value of ER decreased more than the raw materials, whereas GPR increased at a and b values.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5615-5622
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• 2012

Seasonal distributions of the viral abundance and physicochemical parameters were analyzed at three different regions in Gwangyang Bay. Morphological structure of marine virus was observed using transmission electron microscopy. Most of marine virus had bacteriophage-like structure, but some were similar with eukaryotic microalgal virus, Ectocarpus siliculosus virus (EsV). Viral abundance at Group 1 (closed eutrophic region) was higher than viral abundances at Group 2 (closed oligotrophic region) and Group 3 (open oligotrophic region). Seasonal abundances of marine virus at Group 1 were dynamically changed. The viral density was variably changed from maximum $7.33{\times}10^8ml^{-1}$ in August to minimum $0.3{\times}10^8ml^{-1}$ in December and maintained middle value in spring and autumn. The concentration of nitrogen and phosphate sources was correlated with viral abundance. Particularly, seasonal change of dissolved oxygen concentration was opposite to the variation of viral abundance. These results showed that viral abundances were closely related with fluctuation of marine physicochemical environment in Gwangyang bay.

• Journal of Environmental Science International
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• v.20 no.5
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• pp.575-580
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• 2011

This study characterized water quality of groundwater and purified water used for drinking water in 30 schools in Gyeongsangbukdo Province. The results of the study showed that 43% of groundwater and 45% of purified water were not suitable for drinking. Among them, microbial contaminations were the most serious problem. In raw groundwater, the exceeding rates of total colony counts was the highest in August (53.6%). Purified water samples showed higher rate of exceeding drinking water standard for total colony counts while showing lower rate of exceeding drinking water standard for total coliforms and fecal coliforms in March and August. Overall, proper managements for microbial contaminations are required for both groundwater and purified water. Furthermore, special attention should toward students not to drink water when groundwater or purified water exceeds the drinking water quality standard.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.354-357
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• 2004

The addition of oxygenates to diesel fuel can significantly reduce particulate emissions. Dibutyl maleate (DBM) and tripropylene glycol methyl ether (TGME) have been identified as possible additives based on their physicochemical characteristics and performance in engine test. However, their potential environmental impacts are unknown. therefore, practical considerations in the selection of an oxygenate additives should include cost, availability, compatibility with engines and fuel, and, particularly, its overall environmental impact. This study was investigated to determine optimal condition for the analysis of potential diesel oxygenates using SPME technique with GC-FID. Four fibers were compared and CAR/PDMS fiber was found to be the most sensitive when used direct-sampling. An absorption time of 30min and a desorption time of 5min provided to be the most sensitivity. The effects of experimental parameters such as the addition of salts, agitation, absorption time, compositon on the analysis were investigated. Analytical parameter such as linearity was also evaluated.

• Journal of the Korean Chemical Society
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• v.55 no.6
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• pp.912-918
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• 2011

Tetraaza Schiff base macrocyclic ligands, $L^1$,$L^2$ and their transition metal chelates have been synthesized and characterized by elemental analyses, IR, electronic, EPR and $^1H$ NMR spectra, TGA and magnetic measurements. The molar conductance of one milli-molar solution of the complexes measured in DMF indicates that the divalent metal complexes are nonelectrolyte while those of trivalent metal ion, are 1:1 electrolytic in the same solvent. The reduction of Racah parameter from the free ion value confirms the presence of considerable covalence of metal ligand sigma bond in the Co(II) and Mn(II) complexes. The EPR spectra of Cu(II) complexes at room temperature shows axial symmetry indicating a $d_x{^2}_{-y}{^2}$ ground state with significant covalent character. The thermal analysis suggests that the complexes do not contain water molecules because only the metal is left as residue.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.751-755
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• 2006

Physicochemical properties of black rice flours (BRFs) produced under different milling conditions were investigated to explore their applications for various processed rice products. Moisture contents of BRFs after roll milling and subsequent hot-air drying or microwave drying were 10.3% and 14.4%, respectively. The BRFs with jet milling and subsequent hot-air drying or microwave drying showed moisture contents of 7.9% and 7.5%. Mean particle sizes of the BRFs obtained from roll milling, jet milling, and following air-classification were 150, 41.5, and 9.4 ${\mu}m$, respectively. Hunter L value and water soluble index (WSI) of BRFs increased with decreasing particle size, while Hunter a value decreased. Total polyphenol contents of 91.4-115.8 mg/100 g and total amino acids of 75.0-96.4 mg/100 g in three types of BRFs were higher as compared to those (6.3 mg/100 g and 30.5 mg/100 g) of polished rice flour (PRF). Physicochemical properties such as moisture content, color parameter, and WSI have close relationship with the particle size of BRFs prepared under different milling conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.4
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• pp.531-538
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• 2003

To elucidate the physicochemical change of Panicm miliaceum powders caused by irradiation and identify detection of irradiation, viscosity, TBA value, Hunter color and total viable count were measured after irradiation of Panicum miliaceum powder. Panicum miliaceum powders from Korea and China were irradiated at 0, 2.5, 5, 7.5, 10, 15 kGy using a $Co^{60}$ irradiator and stored for 9 months at $0^{\circ}C$ and $20^{\circ}C$. All samples resulted in decrease for viscosity and specific parameter values by increasing dosage at 50 rpm after irradiation. These values showed dose-dependent relationship (above $r^2$＝0.92) between non-irradiated and irradiated samples during storage. These results suggest that the detection of irradiated Panicum miliaceum at various doses is possible by using viscometric method during storage. Total viable count, TBA value and Hunter color were determined as assistant indices for the samples viscosity measured. Total viable count, TBA values showed dose-dependent relationship (2.5 ~15 kGy). The difference in viscosity along with total viable count, TBA values between non-irradiated samples little or some changed with the lapse of post-irradiation time, but was still distinguishable each other more than 6 months at $0^{\circ}C$ and $20^{\circ}C$ for Panicum miliaceum powders from Korea and China.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.33-38
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• 1993

In order to utilize Kumquats as a processed products, a Citrus varieties produced in Cheju island, physicochemical properties of Kumquats, sensory evaluation of frozen Kumquats, sensory evaluation and texture parameter of Kumquats processed foods were investigated. Fruit size, weight, peel ratio, peel thickness, and Brix/acid ratio of Youngpa Kumquats cultivated in green house were 29.5 mm, 16.10g, 4.63 mm and 20.0 respectively, and it was suitable for as raw-eating and processing materials. Kumquats juice consisted of 58.27% citric acid, 32.49% malic acid, 9.14% tartaric acid and 0.08% maleic acid of total organic acids. Organic acid contents of Kumquats juice was very different from Citrus unshiu juice in malic acid content. Sensory evaluation on frozen Kumquats stored at $-18^{\circ}C$ for 6 month was good for appearance, taste and texture as summer commodity. Vitamin C content of frozen Kumquats was 74.94 mg/100g, and its content was decreased slightly during fronzen storage. Hardness on Kumquats jam was lowered from 1,294 to 355 g-force as the ratio of Kumquats juice content was increased, but the changes of other texture parameter were not so large. Kumquats jam contained $40{\sim}60%$ orange juice was evaluated as superior to orange jam for panelists.