• Journal of Magnetics
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• v.9 no.4
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• pp.125-127
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• 2004

We have grown Mn-doped $Bi_2Se_3$ and $Sb_2Se_3$ single crystals using the temperature gradient solidification method. We report on the structural and magnetic propertis of Mn-doped $Bi_2Se_3$ and $Sb_2Se_3$ compound semi-conductors. The lattice constants of several percent Mn-doped $Bi_2Se_3$ and $Sb_2Se_3$ were slightly smaller than those of the un-doped samples due to the smaller Mn atomic radius ($1.40 {\AA}$) than those of Bi ($1.60 {\AA}$) and Sb ($1.45 {\AA}$). Mn-doped $Bi_2Se_3$ and $Sb_2Se_3$ showed spin glass and paramagnetic properties, respectively.

• 연구논문집
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• s.33
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• pp.137-145
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• 2003

The effects of antimony addition on the microstructures and creep behavior of AZ31 magnesium alloy have been investigated. Constant load creep tests were carried out at temperatures ranging from $150^{\circ}C$ to $200^{\circ}C$, and an initial stress of 50MPa for AZ31 alloys containing antimony up to 0.84% by weight. Results show that small additions of antimony to AZ31 effectively decreased the creep extension and steady state creep rates. The steady state creep rate of AZ31 was reduced 2.5 times by the addition of 0.84% of antimony. The steady state creep rate of AZ31-0.84Sb alloy was controlled by dislocation climb in which the activation energy for creep was 128 kJ/mole. The microstructure of as-cast AZ31-0.84%Sb alloy showed the presence of $Mg_3Sb_2$ precipitates dispersed throughout the matrix. The main reason for the higher creep resistance in AZ31-Sb alloys is due to the presence $Mg_3Sb_2$, which effectively hindered the movement of dislocations during the elevated temperature creep.

• Korean Journal of Materials Research
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• v.12 no.3
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• pp.169-175
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• 2002

Semiconductive nano $(Ba_{1-x}Sb_x)TiO_3$ powders were synthesized by the hydrothermal process and Sb was simultaneously doped in the hydrothermal condition. $(Ba_{1-x}Sb_x)TiO_3$ powders obtained from optimum condition(at 20$0^{\circ}C$ for 3hr) exhibited spherical shape, high purity and nano size. The PTCR characteristics was observed when 0.1 and 0.2 mole% Sb were added and sintered at over 130$0^{\circ}C$ for 1 hour, respectively. And The ceramics exhibit the PTCR characteristics with a resistively jump $ratio($\rho$_{max}/$\rho$_{min})$ of about $10^4$. Also we found that PTCR characteristics were dependent on the microstructure.

• Journal of Korea Foundry Society
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• v.11 no.6
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• pp.463-474
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• 1991

The effect of $0.01{\sim}0.10%$ Sb and Sn on the wear resistance of ductile cast iron was investigated. The hardness was increased with Sb to 0.10%, but the elongation and the impact value were decreased. The tensile strength was increased with up to 0.05% Sb, however decreased with $0.05{\sim}0.10%$ Sb. The hardness and the tensile strength were increased and the elongation was decreased with up to 0.10% Sn. The nodularity of graphite was decreased with above 0.08% Sb however Sn had no effect on that. When the maximum compressive stress was low ($42kg.f/mm^2$), the weigth loss was decreased with increased hardness and when that was high ($54kg.f/mm^2$ and $65kg.f/mm^2$), the weight loss did not depend upon the hardness. The pearlite stabilization with Sb and Sn increased with the wear resistance of ductile cast iron.

• Journal of the Korean Institute of Telematics and Electronics
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• v.12 no.4
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• pp.35-40
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• 1975

The Zn7e-lnSb heterojunctions was prepared by interface alloying technique. The structure of this beterojunction had p-i-n which semi-insulating ZnTe laver at interface of this heterojunction was formed by diffusing In of InSb into ZnTe crystal. The current transport mechanism of this heterojunction was Spacecharge-Limited-Current(SCLC) mechanism by hole at semi-insulating ZnTe layer. The hole wart injected from valence band of p- type SnTe crystal. Orange color electroluminescence was observed at this heterojunction when forward and reversed bias voltage applied.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.5
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• pp.519-529
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• 2017

Sodium butyrate (SB) has various metabolic actions. However, its effect on dipeptidyl peptidase 4 (DPP-4) needs to be studied further. We aimed to evaluate the metabolic actions of SB, considering its physiologically relevant concentration. We evaluated the effect of SB on regulation of DPP-4 and its other metabolic actions, both in vitro (HepG2 cells and mouse mesangial cells) and in vivo (high fat diet [HFD]-induced obese mice). Ten-week HFD-induced obese C57BL/6J mice were subjected to SB treatment by adding SB to HFD which was maintained for an additional 16 weeks. In HepG2 cells, SB suppressed DPP-4 activity and expression at sub-molar concentrations, whereas it increased DPP-4 activity at a concentration of $1,000{\mu}M$. In HFD-induced obese mice, SB decreased blood glucose, serum levels of insulin and $IL-1{\beta}$, and DPP-4 activity, and suppressed the increase in body weight. On the contrary, various tissues including liver, kidney, and peripheral blood cells showed variable responses of DPP-4 to SB. Especially in the kidney, although DPP-4 activity was decreased by SB in HFD-induced obese mice, it caused an increase in mRNA expression of $TNF-{\alpha}$, IL-6, and $IL-1{\beta}$. The pro-inflammatory actions of SB in the kidney of HFD-induced obese mice were recapitulated by cultured mesangial cell experiments, in which SB stimulated the secretion of several cytokines from cells. Our results showed that SB has differential actions according to its treatment dose and the type of cells and tissues. Thus, further studies are required to evaluate its therapeutic relevance in metabolic diseases including diabetes and obesity.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.3
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• pp.389-398
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• 2008

The purpose of this study was to evaluate the effects of collagenase and esterase on dentin bond strength and nanoleakage. Resin composites were bonded to occlusal dentin of premolars with Single Bond 2(SB) and Clearfil SE Bond(SE). After the microtensile specimens were prepared and stored in PBS for 24 hours(I) or, PBS(II), collagenase(III), esterase(IV) solution for 4 weeks, the specimens were stained with silver nitrate solution. Microtensile bond strength(${\mu}TBS$) and silver penetration area were measured and, the results were as follows: 1. For group II, III, and IV, the bond strengths of SB were lower than those of SB(p<0.05). The bond strengths of SB II, III, and IV were lower than that of SB I(p<0.05). There was no difference among the bond strengths of SE $I{\sim}IV$ groups(p>0.05). 2. Silver penetration areas of SB were higher than those of SE for all storage groups(p<0.05). In SB and SE groups, there was no significant difference of silver penetration area among $I{\sim}IV$ groups(p>0.05). 3. SE I, II, and III showed inverse relationship between the bond strengths and the silver penetration areas(p<0.05).

• Journal of the Korean Dietetic Association
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• v.6 no.1
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• pp.9-16
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• 2000

This study was carried out with 436 college students in Chungnam to investigate the relationship between residences and eating patterns of college students. The subjects were devided into two groups; those who live in self-boarding house(SB) and home with parents(HWP). The results were as follows. An average height, weight and BMI were 173.5cm, 66.0kg and 21.9 in male SB and 161.8cm, 50.2kg and 19.2 in female SB and 172.9cm, 67.6kg and 22.6 in male HWP and 161.2cm, 50.9kg and 19.6 in female HWP, respectively. There were no significant differences in the general characteristics between the SB and the HWP. The proportions of disease possession, vitamin/mineral supplements and physical exercise were not significantly different between two groups by residences. Sleeping time of the SB was longer than that of the HWP. And, frequency of cigarette smoking and alcohol drinking of the SB were higher than those of the HWP. The proportions of skipping meals in the SB were higher than those in the HWP. Approximately 40.42% of the SB tended to skip the breakfast, while 11.26% of the HWP did. It turns out that the most common reason why skipped meals was due to a eating habit(44.21%) in the SB and a lack of time(48.85%) in the HWP, respectively. The survey shows that while a great majority of the SB had lunch at campus(50.00%) and home(30.00%), the HWP ate lunch at campus(33.79%) and restaurant(33.33%). About 48% of the SB ate out more than 2-3 times a week compared to 42% of the HWP. The daily intakes of calcium, iron, vitamin A, vitamin $B_2$, niacin and vitamin C in the SB were significantly higher than those in the HWP. The percent RDAs of calcium and iron intakes were lower in female students than in male students. In conclusions, students of self-boarding had more dietary problems than students of home with parents. These results suggest that college students of self-boarding might have low ability of meal management. Therefore, nutrition education for college students is needed, and menus of campus cafeterias should be developed to meet the various needs of students.

• Journal of the Korean Vacuum Society
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• v.18 no.4
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• pp.245-253
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• 2009

For the growth optimization of InAs/GaSb (8/8-ML) strained-layer superlattice (SLS), the structure has been grown under various conditions and modes and characterized by the high-resolution x-ray diffraction (XRD) analysis. In this study, the strain modulation is induced by changing parameters and modes, such as the growth temperature, the ratio of V/III beam-equivalent-pressure (BEP), and the growth interruption (GI), and the strain variation is analyzed by measuring the angle separation of 0th-order satellite peak in XRD patterns. The XRD results reveal that the growth temperature and the V/III(Sb/Ga) ratio are major parameters to change the crystallineity and the strain modulation in SLS structures, respectively. We have observed that the SLS samples with compressive strain prepared in this study are show a transition to tensile strain with decreasing V/III(Sb/Ga) ratio, and the GI process is a sensitive factor giving rise to strain modulation. These results obtained in this study suggest that optimized growth temperature and V/III(Sb/Ga) ratio are $350^{\circ}C$ and 20, respectively, and the appropriate GI time is approximately 3 seconds just before InAs growth that the crystallineity is maximized and the strain relaxation is minimized.

• Korean Journal of Food Science and Technology
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• v.51 no.4
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• pp.330-335
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• 2019

The aim of this study was to investigate the rheological properties of arabinogalactans (AGs) solution isolated from moth bean (MB), navy bean (NB), and soybean (SB) including monosaccharide compositions, intrinsic viscosity, steady shear and dynamic shear rheological properties. The major monosaccharides in MB, NB, and SB were arabinose (64.8, 51.4, and 42.6%) and galactose (13.4, 19.6, and 46.2%). The yield stresses for 5% (w/v) NB and 2.5% (w/v) SB solutions were assessed as 2.10 Pa and 1.98 Pa, respectively, but in case of MB solution, it was observed to be negligible. While 5% MB solution showed rheopectic property, 5% NB and SB solutions showed thixotropic properties. As a result of frequency sweep experiment, the G' values in 2.5% MB and NB were larger than the G" value showed but 2.5% SB exhibited G" value greater than G'. These results would be useful for future application as a food additive in the food industry.