• Journal of the Korean Magnetics Society
• /
• v.2 no.1
• /
• pp.37-43
• /
• 1992

Minor phases in cast and hot-pressed R(R=Pr, Nd)-Fe-B magnet were investigated through thermomagnetic analysis. The relationship between minor phases and coercivities of R-Fe-B magnets was studied. ${\alpha}-Fe$ and $Nd_{2}Fe_{17}$ were precipitated in as-cast Pr-Fe-B and Nd-Fe-B alloys respectively. These phases were considered to deteriorate the magnetic properties of R-Fe-B magnets. During the heat treatment, ${\alpha}-Fe$ and $Nd_{2}Fe_{17}$ were annihilated and the magnetic properties of cast R-Fe-B magnet were improved. Hot-pressed Nd-Fe-B magnet showed better thermal stability than sintered magnet.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.21 no.4
• /
• pp.1017-1024
• /
• 2007

Thymus and activation-regulated chemokine (TARC/CCL-17), produced by keratinocytes, is a CC chemokine known to selectively Th2 type T cells via $CCR4^+$ and is implicated in the development of atopic dermatitis (AD). TARC/CCL17 expression was induced by cytokines such as tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interferon-${\gamma}$ (IFN-${\gamma}$). We recently found that the wogonin, a flavone isolated from Scutellaria baicalensis, suppressed TARC expression via heme oxygenase 1 (HO1) in human keratinocytes induced with mite antigen. However, little is known about the inhibitory mechanism of wogonin on TARC/CCL-17 expression stimulated with cytokines. To investigate the inhibitory mechanism, I determined the inhibitory effects of wogonin on the activation of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and $I{\kappa}B{\alpha}$ phosphorylation, and also examined the activation of p38 MAP kainase in HaCaT keratinocytes stimulated with TNF-${\alpha}$ and IFN-${\gamma}$. Wogonin inhibited NF-${\kappa}B$-DNA complex, NF-${\kappa}B$ binding activity, and the phosphorylation of $I{\kappa}B{\alpha}$ in a dose dependent manner. Wogonin also inhibited the translocation of NF-${\kappa}B$ from cytosol to nucleus. Moreover, the phosphorylation of of p38 MAP kinase in the TNF-${\alpha}$ and IFN-${\gamma}$-stimulated HaCaT keratinocytes were suppressed by wogonin in a dose dependent manner. These results suggest that wogonin may inhibit cytokine-induced NF-${\kappa}B$ activation by $I{\kappa}B{\alpha}$ degradation via suppression of p38 MAP kinase signaling pathway in keratinocytes and modulation of wogonin signaling pathway may be beneficial for the treatment of AD.

• Journal of Oriental Medical Thermology
• /
• v.1 no.1
• /
• pp.13-19
• /
• 2002

Objectives : This study was performed to apply thermography as an method in diagnosis of hwabyung patients. We studied 11 Hwabyung patients who visited to chronic diseases center and circulatory oriental internal medicine of Kangnam oriental medicine hospital and 11 patients control group. Methods : Diagnosis of Hwabyung was based on the dignostic criteria of Hwabyung. The temperature was measured on Chonjung(CV17) Shimsu(B15), Kansu(B18), Kyonjong(G21) in each group. The ${\Delta}T$ was measured between Chonjung(CV17) and Chungjong(CV16), left and right Chungjong(CV16), Shimsu(B15), Kansu(B18), Kyonjong(G21) in each group. We compared the ${\Delta}T$ and DITI types between patients and control group. Results : The ${\Delta}T$ between left and right Chungjong(CV16), Shimsu(B15), Kansu(B18), Kyonjong(G21) were not statistically significant. But the ${\Delta}T$ between Chonjung(CV17) and Chungjong(CV16) was statistically significant(P<0.05) in each group. In control group, DITI type was straight 36%, diamond 27%, multiple small spot 18%, others 18%. In Hwabyung patients group, DITI type was inverse triangle 64%, multiple small spot 9.1%, round 9.1%. Conclusions : The ${\Delta}T$ between Chonjung(CV17) and Chungjong(CV16) and DITI type is considered useful diagnostic methods on Hwabyung patients.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.11 no.5
• /
• pp.748-754
• /
• 2000

A novel single feed wide band CP stacked microstrip antenna using crossed slots has been designed, fabricated and measured. For the single rediating element the designed 10dB return loss bandwidth is 34.5%99.45~13.54 GHz), 3dB axial ratio bandwidth is 18.7%(11.17~13.39GHz), and 6 dB gain bandwidth is 29%(10.21~13.64GHz). For the 2$\times$2 array designed using a sequential rotation method, the 10dB return loss bandwidth is 35.9%(9.69~13.94GHz), 3dB axial ratio bandwidth is 34.6GHz (9.93~14.03GHz), and 6dB gain bandwidth is 27.4%(10.35~13.6GHz). For the fabricated 8$\times$8 array antenna, the 10dB return loss bandwidth is 27.3%(10.17~13.41GHz), 3dB axial ratio bandwidth is 27.9GHz(10.1~13.4GHz), and the radiation pattern is good agreement with theory. This antenna can be used for broadband applications for communications or broadcasting in Ku band.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.17 no.1
• /
• pp.27-31
• /
• 2006

Objectives : We examined whether D8/17 expression in Tourette syndrome children who suggested PANDAS were higher than comparison group, and there was my clinical difference by D8/l7 expression. Methods : Nine Tourette's syndrome children suggested PANDAS and two ADHD children without tic disorder were evaluated far percentage of D8/17 expression-positive B cells by immunofluorescence flow cytometric assay and anti-streptolysin O titer. Results : The frequency of D8/17 positive B lymphocyte rate was significantly higher in Tourette's syndrome than ADHD, whose average rate were 77.9 and 24.8, respectively. Among 9 TD patients,4 patients showed above 90% D8/l7 expression. There was high concordance expression rate between mother (98.4%) and daughter (99.0%) The significant relation between percentage of D8/17 expression and tic severity were not detected. The significant relation between percentage of D8/17 expression and anti-streptolysin O titer were not detected, however in 66.7% TD patients showed above 100IU/ml. Conclusion : We concluded that subgroup of TD children are streptococcal infected tic disorder, so called PANDAS.

• International Journal of Contents
• /
• v.17 no.3
• /
• pp.48-66
• /
• 2021

We proposed a B2B food distribution platform by transforming an established food distribution and management platform based on blockchain technology. Our proposed model introduced a method to bring innovation into the domestic B2B food distribution market and systematically manage and utilize massive data (country of origin, producer, transaction, distributor, final consumer) generated within the food distribution process.

• Journal of the Korean Magnetics Society
• /
• v.3 no.2
• /
• pp.94-100
• /
• 1993

Electronic and magnetic properties of the novel rare-earth permanent magnet, $Sm_{2}Fe_{17}N_{3}$, are investigated by performing self-consistent local density functional electronic structure calculations. Employing the LMTO(Linearized Muffin-Tin Orbital) band method, we have obtained the electronic band structures for both paramag-netic and ferromagnetic phases of $Sm_{2}Fe_{17}N_{3}$. Based on the energy band structures, we have studied bonding ef-fects among Sm, Fe, and N atom as well as electronic and magnetic structures. It is found that the N atom sub-stantially reduces the magnetic moment of neighboring Fe atoms through the hybridization interaction and also plays a role in stabilizing the structure. the average magnetic moment of Fe atoms in the ferromagnetic phase of $Sm_{2}Fe_{17}N_{3}$ is estimated to be $2.33{\mu}_B$, which is ~8% larger than the magnetic moment of $Sm_{2}Fe_{17}$, $2.16{\mu}_B$. The Fe I (c) atom, which is located farthest from the N atom and surrounded by 12 Fe nearest neighbors, has the largest magnetic moment ($2.65{\mu}_B$), while the Fe III (f), whose hybridization interaction with N atom is very strong, has the smallest magnetic moment($1.96{\mu}_B$).

• The Korean Journal of Ecology
• /
• v.27 no.2
• /
• pp.93-98
• /
• 2004

Decay rate and nutrient dynamics during decomposition of oak (Quercus acutissima) branches were investigated for 33-months in Kongju, Korea. After 33-months, remaining weight of B₁, B₂ and B₃ was 44.5%, 58.5% and 55.37%, respectively. Decomposition constant (k) for B₁, B₂ and B₃ was 0.294/yr, 0.195/yr, 0.215/yr, respectively. N concentration in decomposing oak branches increased in all diameter classes. After 33-months, remaining N in B₁, B₂ and B₃ was 101.2%, 91.9%, 104.4%, respectively. P concentration in decomposing oak branches increased in B₁ and B₂, and there was no immobilization period. After 33-months, remaining P in B₁, B₂ and B₃ was 57.2%, 74.4%, 53.9%, respectively. K concentration in decomposing oak branches decreased significantly. Remaining K in B₁, B₂ and B₃ was 7.7%, 17.1% and 17.2%, respectively, which was significantly lower than other nutrients. Ca concentration in decomposing oak branches increased in B₂ and B₃. After 33-months, remaining Ca in B₁, B₂ and B₃ was 58.5%, 47.8% and 75.2%, respectively. Initial concentration of Mg in oak branch was higher in smaller diameter class. After 33-months, remaining Mg in B₁, B₂ and B₃ was 44.3%, 57.9% and 47.7%, respectively.

• Progress in Superconductivity and Cryogenics
• /
• v.17 no.2
• /
• pp.1-17
• /
• 2015

$MgB_2$ thin films with superior superconducting properties are very promising for superconducting magnets, electronic devices and coated conductor electric power applications. A clear understanding of flux pinning mechanism in $MgB_2$ films could be a big aid in improving the performance of $MgB_2$ by the enhancement of $J_c$. The fabrication advancement and the understanding of flux pinning mechanism of $MgB_2$ thin and thick films fabricated by using hybrid physical-chemical vapor deposition (HPCVD) are reviewed. The distinct kind of $MgB_2$ films, such as single-crystal like $MgB_2$ thin films, $MgB_2$ epitaxial columnar thick films, and a-axis-oriented $MgB_2$ films are included for flux pinning mechanism investigation. Various attempts made by researchers to improve further the flux pinning property and $J_c$ performance by means of doping in $MgB_2$ thin films by using HPCVD are also summarized.

• Journal of Korea Foundry Society
• /
• v.20 no.2
• /
• pp.89-96
• /
• 2000

The effects of modification processing on the refinement of primary Si and the wear behavior of hyper-eutectic Al-Si alloys have been mainly investigated. Refining effects of primary Si in Al-17%Si alloy was more efficient than that of B.390 alloy. Optimum condition of getting the finest primary Si microstructure was when AlCuP modifier is added into the melt at $750^{\circ}C$ and held it at $700^{\circ}C$ for 30 minutes. Wear loss in the specimens of as-cast condition decreases as the size of primary Si decreases, in the order of B.390 alloy, B.390 alloy with AlCuP addition, Al-17%Si alloy and Al-17%Si alloy with AlCuP addition. Wear loss in the aged condition of Al-17%Si alloy, B.390 alloy and B.390 alloy with AlCuP addition decreased due to the increase of compressive residual stress in the matrix by the aging treatment. While, wear loss increased in the aged specimens of Al-17%Si alloy with AlCuP addition and Hepworth addition in which compressive residual stress decreases by the aging treatment. Therefore, it is assumed that higher compressive residual stress in the matrix can reduce the wear loss in composite materials such as hyper-eutectic Al-Si alloys.