• Proceedings of the Korean Magnestics Society Conference
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• 2011.06a
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• pp.7-8
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• 2011

Basically, the lattice mismatch between film and substrate can make those BiFeO3(BFO) films distorted with strain structure. BFO phase can be stabilized on LaAlO3(LAO) represents the example of a multiferroic with giant axial ratio. Its crystal structure is not strictly tetragonal, but tetragonal with a slight monoclinic distortion and related to the rotation of the oxygen octahedra. In this study, we show that phases with a tetragonal-like epitaxial BFO films can indeed be ferroelectric and also can be stabilized via epitaxial growth onto LAO. Recent reports on epitaxial BFO films show that the crystal structure changes from nearly rhombohedral ("R-like") to nearly tetragonal("T-like") at strains exceeding approximately -4.5%, with the "T-like" structure being characterized by a highly enhanced c/a ratio. While both the "R-like" and the "T-like" phases are monoclinic, our detailed x-ray diffraction results reveal asymmetry change from MA and MC type, respectively. By applying additional strain or by modifying the unit cell volume of the film by substituting Ba for Bi, the monoclinic distortion in the "T-like" MC phase is reduced, i.e. the system approaches a true tetragonal symmetry. There are two different M-H loops for $Bi_{1-x}Ba_xFeO_{3-{\delta}}$(BBFO) and BFO films on SrTiO3(STO) & LAO substrates. Along with the ferroelectric characterization, these magnetic data indicate that the BFO phase stabilized on LAO represents the first example of a multiferroic with giant axial ratio. However, there is a significant difference between this phase and other predicted ferroelectrics with a giant axial ratio: its crystal structure is not strictly tetragonal, but tetragonal with a slight monoclinic distortion. Therefore, in going from bulk to highly-strained films, a phase sequence of rhombohedral(R)-to-monoclinic ["R-like" MA-to-monoclinic, "T-like" MC-to-tetragonal (T)] is observed. This sequence is otherwise seen only near morphotropic phase boundaries in lead-based solid-solution perovskites (i.e. near a compositionally induced phase instability), where it can be controlled by electric field, temperature, or composition. Our results show that this evolution can occur in a lead-free, stoichiometric material and can be induced by stress alone. Those major results are summarized as follows ; 1) Ba-doping increases the unit cell volume, 2) BBFO on LAO can be fully strained up to x=0.08 as a strain limit (Fig. 1), 3) P(E) & M(H) properties can be tuned by the variation of composition, strain, and film thickness.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.3
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• pp.206-213
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• 2008

We observed the physical and chemical properties of a soil on pine mushroom picking areas where were located in the most upper and lower parts showing a comparative climatic characteristics in Korea. The slope gradients within the investigation areas which were divided into 100 quadrates of $1m^2$ ranged from $5.7{\sim}8.6{\beta}$ to $24{\sim}22.7{\beta}$ (left to right) and $4.5{\sim}6.8{\beta}$ to $13.5{\sim}17.8{\beta}$ (top to bottom) for Ponghwa and Gansung, respectively. The amount of clay and thickness of organic matter were significantly decreased with increasing slope gradient, resulting in decrease of the soil moisture content around a fairly ring-colony of Tricholoma matsutake which was observed under the relatively thicker organic matter layer beyond 3 cm depth. Soil pHswere weak acid and average EC was $0.44dS\;m^{-1}$ in both areas. The cations were in the order of Fe K > Na > Mg > Ca and Fe > K > Na > Ca > Mg for the upper(Gansung) and the lower (Ponghwa) part. And the amount of Fe was approximately $80dS\;m^{-1}$ or greater in the pine mushroom picking soil. From this, we could assume that the growth of the pine mushroom was closely related not only with iron but also soil moisture content.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.682-688
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• 2014

The in vitro digestibility and molecular and crystalline structures of rice starches (Seilmi, Dasan1, and Segoami) with differing amylose content were investigated. Segoami had the highest amylose content (30.9%), whereas Dasan1 had the lowest amylose content (21.2%). The molecular weight ($\bar{M}_w$) of amylose and amylopectin in Segoami was much lower than that of the other two rice starches. Segoami had the highest proportion (8.7%) of amylopectin short branch chains (DP 6-12) and the lowest proportion of B1 chains (DP 13-24). The relative crystallinity, intensity ratio of $1047-1022cm^{-1}$ (1047/1022) and gelatinization enthalpy followed the order: Segoami>Seilmi~Dasan1. Segoami showed substantially low pasting viscosity. Rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) contents showed the highest value in Seilmi, Dasan1, and Segoami, respectively. The expected glycemic index (eGI) of Segoami was lower than that of the other two rice starches. Overall results suggested that the digestibility of rice starch could be highly influenced by their molecular and crystalline structure.

• Korean Journal of Food Science and Technology
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• v.14 no.1
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• pp.49-56
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• 1982

The effects of measurement conditions on the emulsifying capacity(EC) and emulsion stability(ES) of proteins were studied in order to develop laboratory standard methods for the evaluation of emulsifying properties. The EC of proteins decreased with the increments of protein concentration and mixing rate. It increased with the increasing oil addition rate up to 0.8 ml/sec, but did not change at $0.8{\sim}1.2\;ml/sec$. The addition of sodiumchloride enhanced EC of proteins, attaining to the highest EC at 0.3M NaCl for Pro-Fam and 0.1M NaCl for Na-caseinate. The ES of Pro-Fam was higher than that of caseinate. The ES was increased by the increments of protein concentration, oil addition volume, mixing rate and mixing time. The EC and ES showed a close relation to the NSI of proteins, reaching to the lowest values of EC and ES at the isoelectric regions of proteins. The laboratory methods for measurements of emulsifying properties of proteins were established. The emulsifying properties of a laboratory-made soybean protein isolate were compared to those of commercial products by using the methods.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.769-772
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• 2008

The problem of disposing construction waste materials has become a national and social problem. Recycled powder generated in the process of making aggregate, and the recycled powder is land-filled in its entirety. Results of toxicity testing of recycled power show that it contains base-pair substituent mutagenicity. As recycled powder is disposed of as landfill, it can cause secondary contamination such as soil and underground water contamination. There has been very little research made on recycled powder. This study has examined the utilization of concrete mixture by using recycled powder in a mixture instead of cement and compared and analyzed the characteristics of dynamics and workability. This study has examined the application of recycled powder in concrete. Depending on the replacement rate and workability, test piece was manufactured using different mixing rate by CP, WCP, PCP. The CP was used to examine the physical property of concrete and characteristics its dynamics. The letters W of WCP and P of PCP are the initials of water and mixture. They were made using the standard mixing ratiosemphasizing the workability to determine the characteristic of dynamics of concrete based on the mixing ratio of recycled powder. With the increase in the replacement rate, CP had very little change in the strength. But with the decline of slump, the workability was not good. The result of manufacturing WCP and PCP using the standard mixing ratio showed that WCP had a drop in strength compared to the plain. PCP had almost the same value as the plain only when the replacement rate was 10%. When it was higher than that, a reduction in strength was observed.

• Food Science and Preservation
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• v.13 no.5
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• pp.603-610
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• 2006

Korean traditional soy paste (Doenjang) was fermented using Meju prepared by the culture of wild microorganisms in steamed soy beans. During the fermentation, changes in the physicochemical and several functional properties were monitored. Total acidity and amino acidity increased from 0.09 to 0.96, and 2.24% to 3.28% respectively, Amylase and protease activities increased and showed the maximal level after 60 days of fermentation, which were 4.03 and 7.29 units/ml, respectively. However, both enzyme activities decreased after then. The inhibitory activities against tyrosinase and angiotensin converting enzyme increased and reached 20.57 and 38.18% respectively. Antimutagenic activities against N-methyl-N'-nitro-N-nitiosoguanidine and 4-nitro-O-phenylenediamine (NPD) increased for 90 days and roached 70.21 and 60.01% in S. enterica serovar Typhimurium TA100, respectively. Against NPD and 4-nitroquinoline-1-oxide, the antimutagenic activities also increased and reached 50.91 and 46.35% in the strain TA98, respectively.

• Journal of Soil and Groundwater Environment
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• v.23 no.6
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• pp.90-103
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• 2018

Although fluoride is an essential trace element, ingestion of excessive amount of fluoride could have detrimental effect on human health. Generally, the bioavailability of fluoride in soils was low, but it could be harmful to the environment depending on the soil properties. Therefore, it is necessary to understand the concentration distribution, and fate and transport characteristics of fluoride to establish a resonable management strategy for fluoride pollution. This study was conducted to evaluate nationwide fluoride distribution in soils in Korea, as well as its fate and transport characteristics. The average background concentration was 204.5 (15.3~504.8) mg/kg, which is lower than the values of foreign soils. For the three regions of different land use, the average concentration was 229.6 mg/kg in region 1, 195.7 mg/kg in region 2, and 273.4 mg/kg in region 3. The concentration of fluoride was the highest in soils from Youngnam block within tectonic structure derived from metamorphic rocks. The results of sequential extraction to access F bioavailability showed fluoride in soils mainly existed as a residual form, which suggests the bioavailability of fluoride was relatively low. Soil properties such as soil pH, CEC, and clay content were found to affect F bioavailability of soil.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.968-972
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• 2012

Soil chemical properties of agricultural soils in Korea were investigated at four-years interval in order of paddy, plastic film house, upland, and orchard soils since 1999. Paddy soil samples were taken from the surface 15 cm at 4,047, 2,010, 2,110 and 2,110 sites in all provinces of South Korea in 1999, 2003, 2007 and 2010, respectively. Soil chemical properties in Korea except Jeju province were measured. Soil pH and exchangeable calcium and available silicate contents increased with increasing the application rate of silicate fertilizer and with decreasing its application interval. Soil organic matter content also increased from $22.0g\;kg^{-1}$ in 1999 to $26.0g\;kg^{-1}$ in 2011. Average concentration of available phosphate in 2011 was higher than the upper limit of its optimal range for rice cultivation. However, exchangeable magnesium and available silicate contents were below the lower limit of their optimal ranges, which were 80% and 92% of them, respectively.

• Microbiology and Biotechnology Letters
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• v.43 no.1
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• pp.45-55
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• 2015

This study was carried out to demonstrate the anti-inflammatory effect of tuna oil (TO) using LPS-induced inflammation responses and mouse models. First, nitric oxide (NO) and pro-inflammatory cytokines levels were suppressed up to 50% with increasing concentrations of TO without causing any cytotoxicity. Also, the expression of a variety of proteins, such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and nuclear factor kappa B (NF-κB), was suppressed in a dosedependent manner by treatment with TO. Furthermore, TO also inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs), including c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p38 protein kinase (p38). Moreover, in in vivo testing the formation of ear edema was reduced at the highest dose tested compared to that in the control, and a reduction of ear thickness and the number of mast cells was observed in histological analysis. In acute toxicity test, no mortalities occurred in mice administrated 5,000 mg/kg body weight of TO over a two-week observation period. Our results suggest that TO has a considerable anti-inflammatory property through the suppression of inflammatory mediator productions and that it could prove to be useful as a potential anti-inflammatory therapeutic material.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.399-407
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• 2009

Laser induced breakdown spectroscopy(LIBS) is an simple analysis method for directly quantifying many kinds of soil micro-elements on site using a small size of laser without pre-treatment at any property of materials(solid, liquid and gas). The purpose of this study were to find an optimum condition of the LIBS measurement including wavelengths for quantifying soil elements, to relate spectral properties to the concentration of soil elements using LIBS as a simultaneous un-breakdown quantitative analysis technology, which can be applied for the safety assessment of agricultural products and precision agriculture, and to compare the results with a standardized chemical analysis method. Soil samples classified as fine-silty, mixed, thermic Typic Hapludalf(Memphis series) from grassland and uplands in Tennessee, USA were collected, crushed, and prepared for further analysis or LIBS measurement. The samples were measured using LIBS ranged from 200 to 600 nm(0.03 nm interval) with a Nd:YAG laser at 532 nm, with a beam energy of 25 mJ per pulse, a pulse width of 5 ns, and a repetition rate of 10 Hz. The optimum wavelength(${\lambda}nm$) of LIBS for estimating soil and plant elements were 308.2 nm for Al, 428.3 nm for Ca, 247.8 nm for T-C, 438.3 nm for Fe, 766.5 nm for K, 85.2 nm for Mg, 330.2 nm for Na, 213.6 nm for P, 180.7 nm for S, 288.2 nm for Si, and 351.9 nm for Ti, respectively. Coefficients of determination($r^2$) of calibration curve using standard reference soil samples for each element from LIBS measurement were ranged from 0.863 to 0.977. In comparison with ICP-AES(Inductively coupled plasma atomic emission spectroscopy) measurement, measurement error in terms of relative standard error were calculated. Silicon dioxide(SiO2) concentration estimated from two methods showed good agreement with -3.5% of relative standard error. The relative standard errors for the other elements were high. It implies that the prediction accuracy is low which might be caused by matrix effect such as particle size and constituent of soils. It is necessary to enhance the measurement and prediction accuracy of LIBS by improving pretreatment process, standard reference soil samples, and measurement method for a reliable quantification method.