• Korean Journal of Environmental Biology
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• v.21 no.4
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• pp.377-383
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• 2003

The functional Jeungpyuns with dietary fiber containing cereals such as brown rice and barley flour were developed and physiochemical properties were investigated. The water binding capacity had significantly the highest value of 28.4% in raw rice flour, followed by brown rice flour and barley flour. The lowest reducing sugar value was seen in unpolished rice substituted Jeungpyun with value of 5.420 (P<0.05). The amount of reducing sugar decreased slightly after steaming, due to the increased degree of sugar dissociation. The L value of the lightness decreased significantly with the substituted samples (P< 0.05). The barley substituted samples were darker than that of brown rice sample groups with less green and yellow color. Microstructures of starch particles after fermentation showed completely dispersed starch particles with air bubbles and sponge-like structure in all samples after steaming. Thus, functional Jeungpyun replaced with brown rice and barley flour can be successfully formulated and has been influenced by the physicochemical properties.

• Steel and Composite Structures
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• v.15 no.1
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• pp.1-14
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• 2013

Predicting the fire resistance of structures has been significantly advanced by full scale fire tests in conjunction with improved understanding of compartmental fire. Despite the progress, application of insulation is still required to parts of structural steelwork to achieve over 60 minutes of fire rating. It is now recognised that uncertainties on insulation properties hinder adaptation of performance based designs for different types of structures. Intumescent coating has recently appeared to be one of most popular insulation types for steel structures, but its design method remains to be confirmed by empirical data, as technical difficulties on the determination of the material properties at elevated temperatures exist. These need to take into account of further physiochemical transitions such as moving boundary and endothermic reaction. The impetus for this research is to investigate the applicability of the conventional differential equation solution which examines the temperature rise on coated steel members by an inorganic intumescent coating, provided that the temperature-dependent thermal/mechanical insulation properties are experimentally defined in lab scale tests.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.1-5
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• 2000

Physicochemical properties and gelatinization patterns of purple-fleshed sweet potato starch were studied. Shape of starch granule was round and polygonal, X-ray diffraction pattern was Ca-type. Amylose content was 14.4% which was lower than that of other sweet potato starch. Water binding capacity was 82.54%, swelling power and solubility at 8$0^{\circ}C$ were 27.94% and 15.35%, respectively. Initial temperature of gelatinization was 72$^{\circ}C$ using Brabender/Visco/Amylograph, consistency and setback were lower than those of other sweet potato starch. The peak temperature and enthalpy determined by DSC were 68.1$^{\circ}C$, 1.24cal/g, respectively. The transmittance of starch dispersions in alkaline solutions increased with NaOH concentration up to 0.17N, and then changed slowly at 0.19N or above. The apparent viscosities were similar to the transmittance of starch dispersions in alkaline solutions, but drastically increased above 0.21N.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.1
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• pp.8-15
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• 2014

In order to evaluating physiochemical properties of soil under minimum tillage and direct seeding cultivation on dry rice paddy, we conducted to analyze the soil physiochemical characteristics in treatment with 2-year minimum tillage and dry direct seeding (2MT), 3-year minimum tillage and dry direct seeding (3MT), and tillage transplanting cultivation (TT). As results of analyzing soil organic matter (OM) contents with 2 cm soil depth of interval from surface to 30 cm, OM contents with surface soil from 0 to 2MT and 3MT were higher than TT, recorded 34.6, 28.1 and $19.8gkg^{-1}$, respectively. But until 20cm in soil depth, it was not so large on the deviation of OM contents among the 3 treatments comparing with 2cm surface. Beneath 20 cm in soil depths, 2- and 3-year, OM contents in TT were distributed to be lower than 2MT and 3MT. The contents of total nitrogen in 2MT and 3MT were higher than the content in TT across the soil profile. Consequently, though minimum tillage and direct seeding farming is obviously the practice to saving of machinery work and labor, other practices such as continuously input OM should be needed to achieve carbon sequestration goal through minimum tillage and direct seeding on dry paddy.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.1
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• pp.131-140
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• 2017

Uniform nanofibers of polyurethane with different content of Juniperus Chinensis extracts (JCE) were successfully prepared by the electrospinning method. We investigated physiochemical properties of prepared compound nanoweb according to various concentrations of Juniperus Chinensis extracts using a Fourier transform infrared (FT-IR) spectrometer, X-ray diffractometer (XRD), thermogravimeter (TGA), and differential scanning calorimeter (DSC). The antibacterial activity of the JCE loaded PU nanofiber was conducted using the disk diffusion test against Gram-positive and Gram-negative bacteria. JCE was induced in the infrared spectra in the absorption band of PU/JCE nanowebs at $3,300cm^{-1}$, $2,960cm^{-1}$, $1,400-1,600cm^{-1}$, and $1,050cm^{-1}$. Thermal stability decreased with increasing JCE content in the PU/JCE nanowebs. The DSC curve of the PU nanoweb shows an endotherm peak at $420^{\circ}C$; in addition, the peak also became smaller and broader with increasing JCE content. The diffraction intensities of PU observed at 2 theta of $20^{\circ}$ decreased with the increasing amount of JCE in the compound nanoweb. In addition, the crystal intensities of the compound nanowebs also decreased along with the JCE content. Structural analysis indicates that JCE and PU are miscible. Juniperus Chinensis incorporated PU nanofibers demonstrated excellent antibacterial properties against both Gram-positive and Gram-negative bacteria.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.3
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• pp.408-413
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• 2012

This study aimed to evaluate the physiochemical properties and fermentation qualities of kimchi supplemented with yacon (Smallanthus sonchifolius) during fermentation. Kimchi supplemented with 0%, 0.1%, 0.5%, 1%, and 5% yacon were investigated. As fermentation proceeded, pH decreased from 5.5~5.7 on the first day to 4.6~4.8 on day 21, whilst total titratable acidity (TTA), lactate levels, and number of microbes increased. The kimchi with 5% yacon showed a higher production of lactate concentration at 7 days fermentation than other groups, which is consistent with the observed high numbers of viable Leuconostoc sp. cells at 7 days fermentation. These observations demonstrate that 5% yacon stimulates the growth of kimchi microbes, particularly of Leuconostoc sp..

• Korean Journal of Pharmacognosy
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• v.47 no.1
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• pp.84-91
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• 2016

Korean ginseng (Panax ginseng C. A. Meyer) has been used as a traditional herbal medicine in East Asia and is very popular in the world, because of its health benefits. To comparison of pharmacological components and physiochemical properties between white and red ginseng from same body, we analyzed ginsenoside and malonyl ginsenoside, ash, crude lipid/protein, fatty acid, mineral contents, total/reducing sugar, and total phenolic and acidic polysaccharide contents. The general components did not show any significant difference between white and red ginseng. Whereas, the content of neutral ginsenoside $Rb_1$, $Rb_2$, Rc and Rd were higher in red ginseng than those of white ginseng. However, malonyl ginsenoside such as $m-Rb_1$, $m-Rb_2$, m-Rc and m-Rd in white ginseng were similar to neutral ginsenoside $Rb_1$, $Rb_2$, Rc and Rd in white ginseng and far higher than those of red ginseng. These results exhibit that malonyl ginsenosides were converted to neutral ginsenosides in steaming process for red ginseng. So, we suggest that malonyl ginsenoside are necessary to applies in ginsenoside analysis of Korean ginseng.

• Applied Chemistry for Engineering
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• v.32 no.3
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• pp.277-282
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• 2021

Two hydrophobic imidazolium based ionic liquids including 1-benzyl-3-butylimidazolium hexafluorophosphate [BzBIM]PF₆ and 1-pentyl-3-butylimidazolium hexafluorophosphate [PBIM]PF₆ having the same anion and different cation parts were synthesized. The structural composition of these ionic liquids were confirmed with Fourier-transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (¹H-NMR). Their physiochemical properties such as viscosity, ionic conductivity and thermal stability alongside electrochemical potential window range for both ionic liquid electrolytes were characterized and compared to each other. The overall results revealed that [BzBIM]PF₆ has higher thermal and electrochemical stabilities and viscosity than that of [PBIM]PF₆ probably due to the presence of benzyl ring in the imidazolium cation providing strong intermolecular π-π interactions.

• Journal of Environmental Science International
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• v.33 no.1
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• pp.27-41
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• 2024

In this study, we evaluated productivity, soil physiochemical properties, and soil microbial characteristics in Kimchi cabbage(Brassica rapa subsp. pekinensis) cultivation within a highland environment during summer. Specifically, we examined the effect of different cropping systems, namely monoculture and rotation with soybean, over an 8-year cropping period. The results of our investigation revealed that significant differences were absent in terms of yield and soil physiochemical properties between the two cropping systems. However, microbial characteristics exhibited distinctive patterns. Bacterial diversity was significantly higher in the rotation system that in the monoculture, whereas fungal diversity demonstrated a preference for rotation although the result was not significant. Our findings identified the presence of Bradyrhizobium stylosanthis, a nitrogen-fixation symbiont, as an indicator ASV (amplicon sequence variant) in the rotation system, where it displayed significantly higher abundances. These observations suggest a potential positive effect of the rotation system on nitrogen fixation. Notably, throughout the cultivation period, both cropping systems did not exhibit critical disease incidences. However, Fusarium oxysporum, a well-known pathogen responsible for inducing fusarium wilt disease in Kimchi cabbage, was detected with significantly higher abundance in the monoculture system. This finding raises concerns about the potential risk associated with Kimchi cabbage cultivation in a long-term monoculture system.

• Food Science and Preservation
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• v.23 no.4
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• pp.538-546
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• 2016

Kochujang was prepared by replacement of rice (25%, control) with pumpkin or purple sweet potato by 0. 5, 10, and 15% (total addition ratio of rice and sweet potato=25% of sample). Effects of the addition of sweet potato on physiochemical properties of fermented Kochujang were investigated. Viable cells of yeast decreased in the sweet potato-added Kochujang at the later stage of fermentation, while there was no significant difference in the number of bacteria among the test groups. As the addition ratio sweet potato increased, ${\alpha}$-amylase activity increased while protease activity decreased. Hunter L, a, and b values of Kochujang prepared with purple sweet potato were lower than those with pumpkin sweet potato. Changes in ${\Delta}E$ value was greater in Kochujang prepared with pumpkin sweet potato than that with purple sweet potato. Oxidation-reduction potential and water activity were higher in sweet potato-Kochujang than control, but reducing sugar content was higher in control. Alcohol and amino-type nitrogen contents were higher in Kochujang prepared with pumpkin sweet potato than that with purple sweet potato, but it was not significant. Overall sensory acceptability was highest in Kochujang prepared with 10% of purple sweet potato while that with 15% pumpkin sweet potato was the least preferred.