• Korean Journal of Agricultural Science
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• v.34 no.2
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• pp.181-188
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• 2007

This study was conducted to estimate the humificating grade according to experiment of physico-chemical characterization and phyto-toxicity during composting of using with pig manure and castor meal. The material ratios of the compost which was mixed with pig manure(P), castor meal(C), and saw dust(S) were 5 : 1 : 4(PCS-I), 5 : 2.5 : 2.5(PCS-II) and 5 : 4 : 1(PCS-III) by volume to volume, and they were decomposed for 60 days. In the result, the changes of temperature in all treatments during composting were rapidly increased more than $68^{\circ}C$ at the incipient stage, and gradually decreased within $39^{\circ}C$ at 60 days the after treatment. pH was slowly increased from 7.5 to 7.7, and the C/N ratio was 13~14 at the final composting stage. The low C/N ratio value in this compost was caused by the castor meal contented high nitrogen level(T-N 5.7 %). G.I.(germination index) was showed 73 to 78 range in all treatments at the $60^{th}$ day. Among all treatments PCS-I was appeared to be the best condition for composting.

• Korean Journal of Food Science and Technology
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• v.22 no.4
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• pp.492-495
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• 1990

In succession to the previous paper(Korean J. Food Sci. and Techn., 21(2), 300, 1989), to investigate effect of salting process on physico-chemical properties of Korean radish cubes processed for kakdugi Ascorbic acid content, ${\alpha}-amylase$ activity, the penetration rate of glucose and red-pepper juice into the radish cubes, and aerobic microbial counts (bacteria, yeast and mold) were investigated during salting (packout ratio : 1:1g/ml) of radish-cube$(2{\times}2{\times}2cm)$ for kakdugi in the 15%(w/v) sodium chloride solution. For 6hr salting, ascorbic acid was reduced from 38.5mg% to 15.7 mg%, ${\alpha}-amylase$ activity was gradually increased until 5hr salting, and then deceased, Amount and rate of penetration of glucose and red-pepper juice(on base of redness) into the salted radish cube were both higher than raw cubes, and microbial counts were decreased, and mostly within one hour of salting.

• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1517-1526
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• 2018

Investigating bacterial diversity and its metabolic capabilities is crucial for interpreting the ecological patterns in a desert environment and assessing the presence of exploitable microbial resources. In this study, we evaluated the spatial heterogeneity of physicochemical parameters, soil bacterial diversity and metabolic adaptation at meter scale. Soil samples were collected from two quadrats of a desert (Thar Desert, India) with a hot, arid climate, very little rainfall and extreme temperatures. Analysis of physico-chemical parameters and subsequent variance analysis (p-values < 0.05) revealed that sulfate, potassium and magnesium ions were the most variable between the quadrats. Microbial diversity of the two quadrats was studied using Illumina bar-coded sequencing by targeting V3-V4 regions of 16S rDNA. As for the results, 702504 high-quality sequence reads, assigned to 173 operational taxonomic units (OTUs) at species level, were examined. The most abundant phyla in both quadrats were Actinobacteria (38.72%), Proteobacteria (32.94%), and Acidobacteria (9.24%). At genus level, Gaiella represented highest prevalence, followed by Streptomyces, Solirubrobacter, Aciditerrimonas, Geminicoccus, Geodermatophilus, Microvirga, and Rubrobacter. Between the quadrats, significant difference (p-values < 0.05) was found in the abundance of Aciditerrimonas, Geodermatophilus, Geminicoccus, Ilumatobacter, Marmoricola, Nakamurella, and Solirubrobacter. Metabolic functional mapping revealed diverse biological activities, and was significantly correlated with physicochemical parameters. The results revealed spatial variation of ions, microbial abundance and functional attributes in the studied quadrats, and patchy nature in local scale. Interestingly, abundance of the biotechnologically important phylum Actinobacteria, with large proposition of unclassified species in the desert, suggested that this arid environment is a promising site for bioprospection.

• Applied Chemistry for Engineering
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• v.29 no.1
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• pp.67-76
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• 2018

In this study, PDMS-HNT and PDMS-mHNT composite membranes were prepared by the addition of halloysite nanotube (HNT) and modified HNT (mHNT) to PDMS. To investigate the physico-chemical characteristics of composite membranes, analytical methods such as FT-IR, XRD, TGA, and SEM were utilized. The gas permeability and selectivity properties of $N_2$ and $CO_2$ were evaluated. In particular, the PDMS-HNT with 10 wt% HNT and PDMS-mHNT with 5 wt% mHNT showed the highest $CO_2/N_2$ selectivity and $CO_2$ permeability at $35^{\circ}C$, respectively. Overall, PDMS-HNT and PDMS-mHNT composite membranes improved the $CO_2/N_2$ selectivity compared to that of using PDMS membrane.

• Korean Journal of Environmental Agriculture
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• v.10 no.2
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• pp.133-137
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• 1991

The inorganic constituents in flay ash such as Ca, Mg, Al and Si were extracted by water and 0.5N-Acetic acid, and changes of the physical properties of the fly ash-treated soils were examined to find out the effect of fly ash on the chemical and physical properties of the soils. The dominant day minerals of fly ash were quartz and mullite. More inorganic constituents were extracted from the fly ash by acetic acid than by water. Si and A1 in fly ash were hardly extracted by water. Addition of fly ash to soil below 10%(W/W) caused improvement in the water permeability and the field moisture capacity of the soil, but did not influence the shrinkage and hardness of the soil. Therefore, it was apparent that the effect of the fly ash on the chemical and physical properties of the soils greatly dependedon soil reaction, the organic acid contents, and the amount of fly ash used in treatment.

• Journal of the Korea Organic Resources Recycling Association
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• v.3 no.1
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• pp.35-42
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• 1995

To evaluate the stability of the compost made from food wastes, which were treated in the fermenting tank for 96 hours and then composted additionally in the static pile, physico-chemical properties and phytotoxicities were investigated. When food wastes were treated in the fermenting tank for 96 hours at $55{\sim}60^{\circ}C$, there is the effect of decreasing about 60% of total weight and improving the storage and the handling. However, it is impossible to make the matured compost in the fermenting tank within 2~3 days, which is the operating condition recommended by manufacturers. To use compost in the agricultural field, after treating food wastes in the fermenting tank for 2~3 days, it needs to compost additionally in the staic pile under the suitable fermenting condition over 6 weeks.

• Journal of Applied Biological Chemistry
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• v.50 no.4
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• pp.275-280
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• 2007

Dried unripe fruits of Rubus coreanus Miq. were extracted with 80% aqueous MeOH and the concentrated extract was partitioned with EtOAc and $H_2O$. From the EtOAc fraction, four triterpenoids were isolated through repeated silica gel, ODS and Sephadex LH-20 column chromatographies. From the result of physico-chemical data including NMR, MS aud IR, the chemical structures of the compounds were determined as tormentic acid (1), myrianthic acid (2), hovenic acid (3) and 2${\alpha}$,3${\beta}$,19${\beta}$,23-tetrahydroxylolean-12-en-28-oic acid (4). Compounds 3 and 4 were isolated for the first time from this plant. All isolated compounds were evaluated for cytotoxic activity against human colon carcinoma cells using in vitro three-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, compound 3 showed a higher cytotoxicity ($IC_{50}$ = 7.8 ${\mu}M$) than doxorubicin ($IC_{50}$= 50 ${\mu}M$).

• Membrane Journal
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• v.22 no.5
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• pp.342-351
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• 2012

In this study, PTMSP[poly(1-trimethylsilyl-1-propyne)]/PDMS[poly(dimethylsioxane)]-NaY zeolite and PTMSP/PDMS-NaA zeolite composite membranes were made to incorporate zeolite into PTMSP/PDMS graft copolymer in order to improve the selectivity and thermal stability, the drop of permeability by physical aging effect during long period of time for the PTMSP membrane. To investigate the physico-chemical characteristics of composite membranes, the analytical methods such as FT-IR, $^1H$-NMR, TGA, SEM, and GPC have been utilized. The gas permeability and selectivity properties of $H_2$ and $N_2$ were evaluated. The permeability of the PTMSP/PDMS-NaY zeolite and PTMSP/PDMS-NaA zeolite composite membranes than PTMSP/PDMS graft copolymer membrane increased, increased as zeolite content increased. On the contrary, the selectivity ($H_2/N_2$) of the composite membranes decreased as zeolite content increased. PTMSP/PDMS-NaA zeolite composite membrane showed better permeability and separation factor than PTMSP/PDMS-NaY zeolite composite membrane.

• Applied Chemistry for Engineering
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• v.23 no.2
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• pp.190-194
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• 2012

10 wt% Mn supported on various commercial $TiO_2$ catalysts were prepared by wet-impregnation method for the low temperature selective catalytic reduction (SCR) of NO with $NH_3$. A combination of various physico-chemical techniques such as BET, XRD, XPS and TPR were used to characterize these catalysts. MnOx surface densities on MnOx/$TiO_2$ catalyst were related to surface area. As MnOx surface density lowered with high dispersion, the SCR activity for low temperature was increased and the reduction temperature ($MnO_2$ ${\rightarrow}$ $Mn_2O_3$) of surface MnOx was lower. For a high SCR, MnOx could be supported on a high surface area of $TiO_2$ and should be existed a high dispersion of non-crystalline species.

• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.755-760
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• 2019

Compound samples based on the mineral-like magnesium potassium phosphate matrix $MgKPO_4{\times}6H_2O$ were synthesized by solidification of high level waste surrogate. Phase composition and structure of synthesized samples were studied by XRD and SEM methods. Compressive strength of the compounds is $12{\pm}3MPa$. Coefficient of thermal expansion of the samples in the range $250-550^{\circ}C$ is $(11.6{\pm}0.3){\times}10^{-6}1/^{\circ}C$, and coefficient of thermal conductivity in the range $20-500^{\circ}C$ is $0.5W/(m{\times}K)$. Differential leaching rate of elements from the compound, $g/(cm^2{\times}day)$: $Mg-6.7{\times}10^{-6}$, $K-3.0{\times}10^{-4}$, $P-1.2{\times}10^{-4}$, $^{137}Cs-4.6{\times}10^{-7}$; $^{90}Sr-9.6{\times}10^{-7}$; $^{239}Pu-3.7{\times}10^{-9}$, $^{241}Am-9.6{\times}10^{-10}$. Leaching mechanism of radionuclides from the samples at the first 1-2 weeks of the leaching test is determined by dissolution ($^{137}Cs$), wash off ($^{90}Sr$) or diffusion ($^{239}Pu$ and $^{241}Am$) from the compound surface, and when the tests continue to 90-91 days - by surface layer depletion of compound. Since the composition and physico-chemical properties of the compound after irradiation with an electron beam (absorbed dose of 1 MGy) are constant the radiation resistance of compound was established.