• Journal of Magnetics
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• v.9 no.2
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• pp.27-33
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• 2004

Magnetic properties of $Nd_4Fe_{77.5}B_{18.5}$ compound in term of exchange coupling between $Nd_2Fe_{14}B$ and $Fe_3B$ magnetic nano crystals in melt spun powders were characterized by varying the quenching speed in mass production line. The exchange coupled phenomenon was characterized as functions of nano crystal size and volume fraction of each magnetic phase which was possible by employing Henkel plot (${\delta}M$) and refined Mossbauer spectroscopy. The optimized magnetic properties obtained from the present volume production line were: $B_r= 11.73 kG,{_i}H_c/ = 3.082 kOe$, and $(BH)_{max} = 12.28 MGOe.$ The volume fraction of each magnetic phase for those conditions giving the grain size of 10 nm were ${\alpha}-Fe; 4.2%, Fe_3B; 60.1 %$, and $Nd_2Fe_{14}B; 35.7%$. The superior magnetic properties in the $Nd_2Fe_{14}Fe_3B$ based nanocomposites were confirmed to be dependant on the volume fraction of $Fe_3B$.

• Preventive Nutrition and Food Science
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• v.3 no.4
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• pp.329-333
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• 1998

Cell wall (lactic acid bacteria-sonicated precipitate ; LAB-SP) and cytosoll(lactic acid bacteria-sonicated supernatant ; LAB-SS) fractions were prepared from kimchi fermenting lactic acid bacteria such as Leuconostoc mesenteroides, Lactobacillus brevis, Lactobacillus fermentum , Lactobacillus plantarum and Pediococcus acidilactici, with Lactobacillus acidophillus isolated from yogurt. Using the Ames mutagenicity test and SOS chormotest system, the antimutagenic acitivity of those cell fractions was studied . One hundered eighty $\mu$l of LAB-SP from lactic acid bacteria isolated from kimchi, excepting Pediococcus acidilactici, supressed the mutagenicity of 4-nitroquinoline-1-oxide(4-NQO) in Ames mutagenicity test and SOS chromotes system , by above 90% and 60% , respectively. LAB-SP from lactic acid bacteria also inhibited the mutagenicity mediated by 3-amino-1-methyl-5H-pyrido [4,3-b]indole (Trp-P-2). Lactobacillus fermentum, Lactobacillus plantarum, and Lactobacillus acidphillus had higher antimutagenicity against Trp-P-2). Lactobacillus fermentum , Lactobacillus plantarum , and Lactobacillus acidphillus had higher antimutagenicity against Trp-P-2 than the other lactic acid bacteria. However, LAB-SS of lactic acid bacteria did not show any mutagenic activity against 4-NQO in Ames mutagenicity test and SOS chromotest systems. On the mutagenicity of MEIQ and Trp-P-2 , LAB-SS of lactic acid bacteria from kimchi or dairy products exhibited a weaker inhibitory effect than LAB-SP of those bacteria. These results represent that, whether the lactic acid bacteria from kimchi are viable or nonviable, antimutagenic acitivity was still effective. We suggest that the strong, antimutaganic activity of lactic acid bacteria might be found in the cell wall fraction , rather than in the cytosol fraction.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.3
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• pp.246-253
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• 1999

Grain size distributions of sediment samples were analyzed by the different methods, and the results were compared. Reported data of the bottom sediments from the Korean seas show significant deviations among the institutes, and the inter-lab comparison and calibration procedures are considered to be necessary. Grain size data by different methods show different results. Laser diffraction method provides good precision in replicate analysis, but underestimates the amounts of finer (smaller than 2-3 ${\mu}m$) fraction. Data from particle settling method, on the other hand, represent significant errors in the coarse silt (5-6 ${\phi}$) fraction, and slightly overestimate the clay fraction. In the sieve and pipette methods, best results were taken in 0.5 ${\phi}$ interval of analysis. Especially in the coarse silt fraction, pipette analysis is suggested to be made with 0.5 ${\phi}$ interval. During the dry sieving procedure in 1 ${\phi}$ interval, serious errors occur when large amounts of sample materials were concentrated in a particular sieve.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.5
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• pp.643-647
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• 2004

An in vitro experiment was carried out to investigate effects of solid associated (SAB) and liquid associated bacteria (LAB) and the type of incubation substrate on ruminal fermentation and gas production profiles. Bacterial fraction did not influence total numbers of bacteria. Gas production degradation parameters were significantly influenced by bacterial fraction and type of substrate (p<0.05). There was significant interaction between bacterial fraction and type of substrate in gas production (p<0.01). Total VFA concentration and acetic and propionic acid ratio were also influenced by bacterial fraction and type of substrate with little differences in individual VFA concentration.

• Food Science of Animal Resources
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• v.25 no.2
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• pp.244-249
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• 2005

To investigate the effect of Holstein colostrum peptide fraction on proliferation of immune cell, polypeptide fractions were separated from acid whey into 3 fractions depending on molecular weight by ultrafiltration: Fraction I, which contains the polypeptide larger than 10,000 Da, Fraction n, which contains the polypeptide ranging from 1,000 Da to 10,000 Da and Fraction III, which contains the polypeptide smaller than 1,000 Da. EL-4 cell (murine T lymphoma cell) was used to evaluate immune enhancing effect of each fraction from Holstein colostrum. Fraction n showed the highest proliferative effect of the colostrum whey fractions on EL-4 cell at 1mg/mL compared with whole whey and other fractions and this proliferative activity was shown in dose dependent manner. Fraction n showed the highest proliferative effect on PMA (Phorbol 12-myristate 13-acetate) stimulated EL-4 cell. Heated Fraction n showed similar effect to native one on proliferation of both EL-4 cell and PMA stimulated EL-4 cell.

• Journal of Soil and Groundwater Environment
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• v.21 no.6
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• pp.87-100
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• 2016

Biochar, which has high alkalinity, has widely studied for amendment of soil that contaminated with heavy metals. The aim of this study is assessment of amendment for arsenic and heavy metals contaminated acidic agricultural soil using biochar that derived from buffalo weed (A. trifida L. var. trifida). Pot experiments were carried out including analysis of soil solution, contaminants fractionation, soil chemical properties and plant (lettuce) uptake rate. Arsenic and heavy metals concentrations in soil solution showed relatively low in biochar added experiments when compared to the control. In the heavy metals fractionation in soil showed decrease of exchangeable fraction and increase of carbonates fraction; however, arsenic fractionations showed constant. Soil chemical properties indicated that biochar could induce recovery of soil quality for plant growth in terms of soil alkalinity. However, phosphate concentration in biochar added soil decreased due to Ca-P precipitation by exchangeable calcium from biochar. Arsenic and heavy metals uptake rate of plant in the amended experiment decreased to 50% when compared to the control. Therefore biochar derived from buffalo weed can be used as amendment material for agricultural soil contaminated with arsenic and heavy metals. Precipitation of As-Ca and metal-carbonates are major mechanisms for soil amendment using char.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.237-238
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• 2008

This paper presents a cognitive radio network where a base station exploits multi-antennas. For the system, a joint power control and user selection greedy algorithm which achieve a significant fraction of sum-capacity at lower complexity cost is proposed.

• Korean Journal of Medicinal Crop Science
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• v.6 no.2
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• pp.126-130
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• 1998

Effects of organic solvent fractions from perilla ethanol extract on alcohol metabolism in rats were examined and the results were as follows: Ethanol souble fraction, after a single oral administration to rats, was found to cause a significant decrease in the serum ethanol concentration as well as enhancement of liver cytosolic alcohol dehydrogenase (ADH) activity. On the other hand, the fraction insouble in ethanol was found to increase ethanol concentration in the blood and inhibit ADH activity.

• Journal of Magnetics
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• v.4 no.2
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• pp.39-45
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• 1999

Sandwich structures of$ Nd_2Fe_{14}B/Fe/Nd_2Fe_{14}B $magnetic films have been grown by a KrF excimer laser (λ=248 nm) ablation technique. Magnetic properties were characterized by varying the thickness of hard ($Nd_2Fe_{14}B$) and soft (Fe) magnetic films and the volume fraction as well. In the (x)nm[NdFeB]/(y)nm[Fe]/(x)nm[NdFeB]/(100) Si structure the thickness (x) was varied from 3.6 to 54 nm, and (y) from 15 to 112 nm. At (y) = 15~20 nm where the volume fraction of Fe corresponded to 61~75%, the sandwich structure exhibited an enhanced Mr/Ms and iHc as well from the result of the exchange coupling between the magnetic layers. Experimentally calculated exchange constant$ (A_s) of A_s = 2.5{\times}10^{-10} J/m$ was estimated using the intrinsic coercivity (iHc) of 1.2 kOe at 5 K for the sandwich magnetic trilayers.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.2
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• pp.297-304
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• 2006

Insulin-like growth factor-I (IGF-I) rich fraction, collected components between 1 kDa and 30 kDa, was fractionated from bovine colostral whey using an ultrafiltration membrane. IGF-I was confirmed in the collected IGF-I rich fraction by both SDS-PAGE and Western blotting. The concentration of IGF-I in the IGF-I rich fraction was 10 ng/mg protein. One hundred microliters of the reconstituted IGF-I rich fraction was intraperitoneally injected into ICR male mice for 2 weeks at 24 h intervals. The functions of peritoneal macrophages, including phagocytosis, interleukin (IL)-6 and tumor necrosis factor (TNF)-${\alpha}$ production, and nitric oxide and hydrogen peroxide production, were enhanced significantly by the administration of the IGF-I rich fraction in a dose-dependent manner (p<0.01). The proliferation of Concanavalin (Con) A-stimulated and Lipopolysaccharide (LPS)-stimulated splenocytes was also determined to have been enhanced significantly by the administration of the IGF-I rich fraction in a dose-dependent manner (p<0.01). Our results indicate that the administration of IGF-I rich fraction obtained from bovine colostral whey enhances both innate and acquired immunity for ICR male mice.