• Journal of Powder Materials
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• v.15 no.3
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• pp.182-187
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• 2008

Carbon was known to be one of effective additives which can improve the flux pinning of $MgB_2$ at high magnetic fields. In this study, glycerin $(C_3H_8O_3)$ was selected as a chemical carbon source for the improvement of critical current density of $MgB_2$. In order to replace some of boron atoms by carbon atoms, the boron powder was heat-treated with liquid glycerin. The glycerin-treated boron powder was mixed with an appropriate amount of magnesium powder to $MgB_2$ composition and the powder pallets were heat treated at $650^{\circ}C\;and\;900^{\circ}C$ for 30 min in a flowing argon gas. It was found that the superconducting transition temperature $(T_c)$ of $Mg(B_{1-x}C_x)_2$ prepared using glycerin-treated boron powder was 36.6 K, which is slightly smaller than $T_c$(37.1 K) of undoped $MgB_2$. The critical current density $(J_c)$ of $Mg(B_{1-x}C_x)_2$ was higher than that of undoped $MgB_2$ and the $T_c$ improvement effect was more remarkable at higher magnetic fields. The $T_c$, decrease and $J_c$ increase associated with the glycerin treatment for boron powder was explained in terms of the carbon substitution to boron site.

• Journal of the Korean Magnetics Society
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• v.19 no.4
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• pp.152-155
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• 2009

Ba-Ferrite single crystals were prepared and the magnetic and thermal properties were characterized by Mossbauer spectroscopy. The single crystal layer was cut in the c-axis and radiated to the surface by ${\gamma}$-rays for Mossbauer spectroscopy. We found out that the spin states in Fe ions were parallel to the ${\gamma}$-rays direction and the whole crystal bulk formed only one crystal with the same spin direction. $M\"{o}ssbauer$ spectra in single crystal have only 4 sets of 4 absorption lines in each Fe site when the ${\gamma}$-rays have the same radiation direction with the c-axis in the crystal, and there was no 2b-site spectrum. The zero absorption of 2b-site means that there was a fast diffusion motion in a double-well atomic potential at room temperature, in which bipyramidal Fe ions have the two minima at each side mirror plane.

• Journal of applied mathematics & informatics
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• v.39 no.3_4
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• pp.381-403
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• 2021

Consider the three-dimensional system of difference equations $x_{n+1}=\frac{{\prod_{j=0}^{k}}z_n-3j}{{\prod_{j=1}^{k}}x_n-(3j-1)\;\(a_n+b_n{\prod_{j=0}^{k}}z_n-3j\)}$, $y_{n+1}=\frac{{\prod_{j=0}^{k}}x_n-3j}{{\prod_{j=1}^{k}}y_n-(3j-1)\;\(c_n+d_n{\prod_{j=0}^{k}}x_n-3j\)}$, $z_{n+1}=\frac{{\prod_{j=0}^{k}}y_n-3j}{{\prod_{j=1}^{k}}z_n-(3j-1)\;\(e_n+f_n{\prod_{j=0}^{k}}y_n-3j\)}$, n ∈ ℕ₀, where k ∈ ℕ₀, the sequences $(a_n)_{n{\in}{\mathbb{N}}_0$, $(b_n)_{n{\in}{\mathbb{N}}_0$, $(c_n)_{n{\in}{\mathbb{N}}_0$, $(d_n)_{n{\in}{\mathbb{N}}_0$, $(e_n)_{n{\in}{\mathbb{N}}_0$, $(f_n)_{n{\in}{\mathbb{N}}_0$ and the initial values x_-3k, x_-3k+1, …, x₀, y_-3k, y_-3k+1, …, y₀, z_-3k, z_-3k+1, …, z₀ are real numbers. In this work, we give explicit formulas for the well defined solutions of the above system. Also, the forbidden set of solution of the system is found. For the constant case, a result on the existence of periodic solutions is provided and the asymptotic behavior of the solutions is investigated in detail.

• Journal of Food Hygiene and Safety
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• v.2 no.2
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• pp.57-65
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• 1987

ABSTRACT - To examine antihypertensive components of Ganoderma lucidum in Korea, two kinds of fruiting bodies (J and K) were used for extraction with water and the extracts were purified by ethanol precipitation and dialysis. Three fractions, i.e., the aqueous total extract(A), the ethanol supernatant(B} and the purified precipitate(C), were compared for antihypertensive activity in anesthetized spontaneously hypertensive rats (SUR). Although fractions A and B showed the activity, fraction C did not. Particularly, fraction B of sample K produced 44.3% reduction in diastolic blood pressure and 30.6% reduction in heart rate after i.v. administration of a dose of 10 mg/kg. Direct effects of this fraction B to the heart were observed in the isolated blood perfused heart preparation of the dog. It induced positive chronotropic and inotropic responses dose-dependently in the case of sample J. In the case of sample K, marked chronotropic and inotropic effects on atrial muscle but not on ventricular muscle were induced. In both samples, coronary blood flow (CBF) was dose-relatedly increased.reased.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.1
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• pp.3-7
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• 2005

The insulin-like growth factors (IGFs), their receptors, and their binding proteins play key roles in regulating cell proliferation and apoptosis. Insulin-like growth factor binding protein-3 (IGFBP3, OMIM #146732) is one of the proteins that bind to the IGFs. IGFBP3 is a modulator of IGF bioactivity, and direct growth inhibitor in the extravascular tissue compartment. We identified twenty-two novel single nucleotide polymorphisms (SNPs) in IGFBP3 gene in Korean cattle (Hanwoo, Bos taurus coreanae) by direct sequencing of full gene including -1,500 bp promoter region. Among the identified SNPs, five common SNPs were screened in 650 Korean cattle; one SNP in promoter (IGFBP3 G-854C), one in 5'UTR region (IGFBP3 G-100A), two in intron 1 (IGFBP3 G+421T, IGFBP3 T+1636A), and one in intron 2 (IGFBP3 C+3863A). The frequencies of each SNP were 0.357 (IGFBP3 G-854C), 0.472 (IGFBP3 G-100A), 0.418 (IGFBP3 G+421T), 0.363 (IGFBP3 T+1636A) and 0.226 (IGFBP3 C+3863A), respectively. Haplotypes and their frequencies were estimated by EM algorithm. Six haplotypes were constructed with five SNPs and linkage disequilibrium coefficients (|D'|) between SNP pairs were also calculated. The information on SNPs and haplotypes in IGFBP3 gene could be useful for genetic studies of this gene.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.274-279
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• 2001

Creep-fatigue crack growth behavior was experimentally measured particularly when a crack was located in the heat affected region of 1Cr-0.5Mo steel. Load hold times of the tests for trapezoidal fatigue waveshapes were varied among 0, 30, 300 and 3,600 seconds. Time-dependent crack growth rates were characterized by the $C_t$-parameter. It was found that the crack growth rates were the highest when the crack path was located along the fine-grained heat affected zone(FGHAZ). Cracks located in other heat affected regions had a tendency to change the crack path eventually to FGHAZ. Creep-fatigue crack growth law of the studied case is suggested in terms of $(da/dt)_{avg}$ vs. $(C_t)_{avg}$ for residual life assessment.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.8
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• pp.1065-1070
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• 2006

The avian uncoupling protein (avUCP) is a member of the mitochondrial transporter superfamily that uncouples proton entry in the mitochondrial matrix from ATP synthesis. The sequencing analysis method was used to identify nucleotide polymorphisms within the avUCP gene in Korean native chicken (KNC). This study identified ten single nucleotide polymorphisms (SNPs) in the avUCP gene. We analyzed the SNPs of the avUCP gene to investigate whether polymorphism in the gene might be responsible for quantitative variations in economic traits in KNC. Three significant polymorphic sites for economic traits were avUCP C+282T (mean body weight, p<0.05), avUCP C+433T (daily percent lay, p<0.05), and avUCP T+1316C (daily percent lay, p<0.05). The frequency of each SNP was 0.125 (C+282T in avUCP gene exon 1 region), 0.150 (C+433T in avUCP gene intron 1 region), and 0.15 (T+1316C in avUCP gene exon 3 region), respectively. Among the identified SNPs, one pair of SNPs (genotype CC, C+282T and TT, avUCP C+433T) showed the highest daily percent lay (p<0.05) and mean body weight (p<0.05) and the frequency was 0.067. This study of the avUCP gene could be useful for genetic studies of this gene and selection on economic traits for KNC.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.183-183
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• 2002

Many polysaccharides isolated from plants have been shown to enhance various immune responses in vivo and in vitro. Here we demonstrate that polysaccharide isolated from the root of Acanthopanax koreanum (AK) has a unique mode of immunostimulation with regard to its cell-type specificity.(omitted)

• Electronics and Telecommunications Trends
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• v.36 no.1
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• pp.32-42
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• 2021

Innovative developments in wearable and artificial intelligence technologies are accelerating the emergence of a soft suit that can autonomously augment a body's own strength and protect the human body. In this paper, we define the concept of "Exoskin," a new concept specifically derived from the "Road to an Intelligent Information Society" (Technology Development Map 2035) as predicted by the Electronics and Telecommunications Research Institute. In addition, we analyze the development status of each element of this technology and forecast its future development.

• Kyungpook Mathematical Journal
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• v.52 no.1
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• pp.33-38
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• 2012

The purpose of the present paper is to investigate mapping properties of an integral operator in which we show that the function g defined by $$g(z)=\{\frac{c+{\alpha}}{z^c}{\int}_{o}^{z}t^{c-1}(D^nf)^{\alpha}(t)dt\}^{1/{\alpha}}$$. belongs to the class $S(A,B)$ if $f{\in}S(n,A,B)$.