• Progress in Superconductivity
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• v.5 no.2
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• pp.109-113
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• 2004

MgB$_2$ and FeTi composites was prepared to study the effect of FeTi particles on superconductivity of MgB$_2$. The sample, which had contained magnesium, boron and FeTi particles, was synthesized by the Commercial Stainless Steel Tube Enveloping Technique(COSSET) at 92$0^{\circ}C$ for 2 hours. The structure and properties of the sample was investigated by XRD, SEM, and SQUID magnetometer. It was found that there was a little change of T$_{c}$ compared with pure MgB$_2$ superconductor in spite of high percentage of FeTi particles, and there was no proof of structure change of MgB$_2$ superconductor due to FeTi particles. But the high porosity which was appeared in the pure MgB$_2$ was disappeared in the composites. We conclude that FeTi particles do not influence the superconductivity of MgB$_2$ and it is expected that fe-Ti material system will be a good material for a tube of the PIT process and for a substrate of the film.m.

• Progress in Superconductivity and Cryogenics
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• v.19 no.1
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• pp.36-41
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• 2017

The effects of $MgB_4$ addition on the superconducting properties and the microstructure of in situ processed $MgB_2$ bulk superconductors were studied. $MgB_4$ powder of 1-20 wt.% was mixed with (Mg + 2B) powder and then pressed into pellets. The pellets of (Mg + 2B + $xMgB_4$) were heat-treated at $650^{\circ}C$ for 1 h in flowing argon. The powder X-ray diffraction (XRD) analysis for the heat-treated samples showed that the major formed phase in all samples was $MgB_2$ and the minor phases were $MgB_4$ and MgO. The full width at half maximum (FWHM) values showed that the grain size of $MgB_2$ decreased as the amount of $MgB_4$ addition increased. $MgB_4$ particles included in a $MgB_2$ matrix is considered to suppress the grain growth of $MgB_2$. The onset temperatures ($T_{c,onset}$) of $MgB_2$ with $MgB_4$ addition (0-10 wt.%) was between 37-38 K. The 20 wt.% $MgB_4$ addition slightly reduced the $T_{c,onset}$ of $MgB_2$ to 36.5 K. This result indicates that $MgB_4$ addition did not influence the superconducting transition temperature ($T_c$) of $MgB_2$ significantly. On the other hand, the small additions of 1-5 wt.% $MgB_4$ increased the critical current density ($J_c$) of $MgB_2$. The $J_c$ enhancement by $MgB_4$ addition is attributed not only to the grain size refinement but also to the possible flux pinning of $MgB_4$ particles dispersed in a $MgB_2$ matrix.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.6
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• pp.324-327
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• 2009

In the present study, the effect of Ca additions on the ignition and combustion behaviors of Mg alloys has been investigated. Cracks and inclusions were observed at the free surface and interior in as-cast pure magnesium but not in Ca-bearing Mg alloys. There was a tendency that ignition temperature rapidly increased with increasing Ca content in Mg-Ca alloy. Saturated composition for increasing of ignition temperature was related with solid solubility of Ca in Ca-bearing Mg alloys. The protective oxide layers, MgO, could also be found on the combustion surface of Ca-bearing magnesium alloy.

• Journal of Hydrogen and New Energy
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• v.22 no.6
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• pp.780-786
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• 2011

Mg hydride had high hydrogen capacity (7.6%), lightweight and low cost materials and it was promising hydrogen storage material at high temperature. However, commercial applications of the Mg hydride are currently hindered by its high absorption/desorption temperature, and very slow reaction kinetics. one of the approaches to improve the kinetic is $MgH_x$ intermixed with carbon. And it shows that carbon and carbon allotropes have a beneficial effect on hydrogen sorption in Mg. The graphene is a kind of carbon allotropes which is easily desorbed reaction at low temperatures because its reaction is exothermic. In this work, the effect of graphene concentration on the kinetics of Mg hydrogen absorption reaction was investigated. The $MgH_x$-Graphene composites has been prepared by hydrogen induced mechanical alloy (HIMA). The synthesized powder was characterized by XRD and simultaneous TG, DSC analysis. The hydrogenation behaviors were evaluated by using a sievert's type automatic PCT apparatus. In this research, results of kinetic profiles exhibit hydrogen absorption rate of $MgH_x$-5wt.% and 10wt.% graphene composite, as 1.25wt.%/ms, 10.33wt.%/ms against 0.88wt.%/ms for $MgH_x$ alone at 473K.

• Journal of Society of Preventive Korean Medicine
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• v.4 no.1
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• pp.51-69
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• 2000

This dissertation was to research how some metal level within SipJeonDaeBo - Decoction, one of oriental prescriptions, influence Sprague-Dawley animals. 1. Under the experiment with drinking waters there was no metal ${\sim}0.65\;mg/L$ detected. A metal with feed found 0.001-376.983mg/kg. 2. In the mice's kidney, brain, bones used experiment, As searched 0.474 mg/kg, 0.486 mg/kg, 0.314 mg/kg 0.834 mg/kg respectively ; Cd 0.060 mg/kg, 0.045 mg/kg, 0.030 mg/kg, 0.353 mg/kg, ; Co 0.105 mg/kg, 0.063 mg/kg, 0.030 mg/kg, 0.399 mg/kg, ; Cr 0.292 mg/kg, 0.304 mg/kg, 0.234 mg/kg, 0.962 mg/kg, ; Cu 4.201 mg/kg, 3.759 mg/kg, 1.923 mg/kg, 0.484 mg/kg, ; Fe 57.535 mg/kg, 150.571 mg/kg, 17.178 mg/kg, 281.506 mg/kg, ; no Hg, Mn 0.612 mg/kg, 2.968 mg/kg, 0.528 mg/kg, 4.205 mg/kg, ; Ni 0.094 mg/kg, 0.072 mg/kg, 0.078 mg/kg, 27.714 mg/kg, ; Pb 0.269 mg/kg, 0.293 mg/kg, 0.283 mg/kg, 43.142 mg/kg ; Zn 4.149 mg/kg, 21.861 mg/kg, 8.088 mg/kg, 226.283 mg/kg respectively. 3. In level of hazardous metal within idney control group searched 0.194 {\pm}\; 0.052 mg/kg, experimental I g개up $0.189{\pm}0.036\;mg/kg$, experimental I group $0.264 {\pm}{\pm}\;0.179\;mg/kg$. In level of non hazardous metal control group searched $15.917{\pm}5.575\;mg/kg$, experiment I group $17.064{\pm}2.246\;mg/kg$, experiment II group $16.892{\pm}3.586\;mg/kg$. Besides in total level of metal control g.cup detected $6.484{\pm}2.258\;mg/kg$, experiment I group $6.940{\pm}0.914\;mg/kg$, experiment II group $6.915{\pm} 1.508\;mg/kg$ There all was no statistical significance. 4. In level of hazardous metal within the liver control group searched $0.187{\pm}0.048\;mg/kg$, experiment I g개up $0.168[\pm}0.079\;mg/kg$, experiment II group $0.277{\pm}0.159\;mg/kg$. In level of non hazardous heavy metal control group detected $44.925{\pm}18.468\;mg/kg$, experiment I group $39.917{\pm}12.772\;mg/kg$, experiment II group $49.525{\pm}33.484\;mg/kg$. Besides in total concentration control group searched $18.082{\pm}7.395\;mg/kg$, experiment I group $16.068{\pm}5.128\;mg/kg$, experiment II group $19.977{\pm}13.443\;mg/kg$. There was no statistical significance but hazardous metal gets more level in the experilnent group than in the control group. 5. In level of hazardous metal within brain control group searched $0.145{\pm}0.056\;mg/kg$, experiment I group $$0.167{\pm}0.030\;mg/kg, erperiment II group $0.172{\pm}0.123\;mg/kg$. In level of non hazardous heavy metal control group detected $6.488{\pm}0.965\;mg/kg$, experiment I group $7.290{\pm}0.588\;mg/kg$, experiment II group $7.010{\pm}1.627\;mg/kg$. Besides in total concentration control group searched $2.683{\pm}7.395\;mg/kg$, experiment I group $3.017{\pm}0.238\;mg/kg$, experiment II group $2.908 {\pm} 0.711\;mg/kg$. Therefore there was no statistical significance. 6. In level of hazardous metal within bone control group searched $8.172{\pm}5.195 \;mg/kg$, experiment I group $9.128{\pm}4.143\;mg/kg$, experiment II group $9.401{\pm}6.924\;mg/kg$. There is statistical significance(p<0.05). In level of non hazardous metal control group detected $94.065{\pm}36.035\;mg/kg$, experiment I group $147.563 {\pm}79.939\;mg/kg$, experiment II group $142.730{\pm}77.374\;mg/kg$. Besides in total level control group searched $48.530{\pm}16.523\;mg/kg$, experiment I group $64.502{\pm}31.078\;mg/kg$, experiment II group $62.733 {\pm}34.641\;mg/kg$. Therefore there was no statistical significance. 7 In the correlative research as to how each metal influences to ingestion Cd and Co searched 0.954 and Pb and Ni -0.0884 from kidney. Co and Cd was 0.995 and Zn and As -0.190 from liver. Co and Cd were 0.995 and Zn and Cu -0.393 from brain. Co and Cd were 0.998 and Zn and Mn -0.206 from bones

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.3
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• pp.7-12
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• 1999

In this paper, dielectric and strain properties of (1-f-y)PMN-yPT-xST ceramics investigated with the amount of $\textrm{SrTiO}^3$(ST). The $\textrm{SrTiO}^3$ content is ranged within 1~6㏖%. Another compositions with excess MgO also investigated. As the amount of ST is increased, dielectric constant has a maximum value at 5㏖% composition. The Curie temperature is decreased linearly with increasing the amount of ST. Coercive field and ramnant polarization has a maximum value at l㏖% composition. As for the effects of excess MgO, the dielectric constant has been increased by the addition of excess MgO up to 3㏖% to a 0.8PMN-0.12PT-0.04ST specimen. But the strain has been decreased by the addition of excess MgO.

• Journal of Powder Materials
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• v.27 no.4
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• pp.287-292
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• 2020

The subject of this study is a zeolite generated as a by-product of recycling LAS (lithium-aluminum-silicate) resources, a kind of glass and ceramic produced by induction. The zeolite by-product is modified into Mg-zeolite using Mg as a cation to absorb Pb, a heavy metal generated from water pollution caused by recent industrial wastewater. An ion-exchange method is used to carry out the modification process, from zeolite byproduct to Mg-zeolite, and simultaneously absorb the Pb in the heavy-metal solution (99.032 mg/L). It is found that the sodium zeolite in the raw material residue can be modified to magnesium zeolite by reacting it with a mixture solution at 1 M concentration for 24 h. As a result, it is found that the residual Pb (0.130 mg/L) in the heavy metal solution is shown to be absorbed by 99.86%, with successful formation of a Mg-modified zeolite.

• YAKHAK HOEJI
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• v.25 no.3
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• pp.109-114
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• 1981

The authors investigated drug interaction of ibuprofen and prednisolone in antiinflammatory and antipyretic activities. We have found significant differences of the antiinflammatory and antipyretic activities between single and concurrent administration of ibuprofen and prednisolone, using Sprague-Dawley Strain rats, carrageenin as a phlogistic agent and brewer's yeast as a fever inducing agent. 1) Ibuprofen(20mg/kg) was administered to the rats orally and resulted in significant reduction of (31.70 %) the swelling of rat paw induced by carrageenin, 2) prednisolone (9mg/kg) showed significant reduction of (45.76%) the swelling, 3) concurrent administration of ibuprofen (20mg/kg) and prednisolone (9mg/kg) also reduced (57.40%) the swelling. In ibuprofen (125mg/kg) administration, the inhibition rate of edema was 39.32% and in prednisolone (1mg/kg) administration, the rate was 39.04%. In concurrent administration of ibuprofen (125mg/kg) and prednisolone (1mg/kg), the inhibition rate of edema was 63.09%. Concurrent administration of ibuprofen and prednisolone showed more anti-inflammatory effects than single administration of ibuprofen and prednisolone respectively. Prednisolone itself did not show antipyretic effect, but concurrent administration of ibuprofen and prednisolone showed more antipyretic effects than ibuprofen single administratron.

• Journal of Surface Science and Engineering
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• v.51 no.4
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• pp.224-230
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• 2018

In this study, Mg films were prepared on hot dip aluminized steel (HDA) by using a sputtering method as a high corrosion resistance coating. The corrosion resistance of the Mg films was improved by controlling the morphology and the crystal structure of films by adjusting the Ar gas pressure during the coating process. Anodic polarization measurement results confirm that the corrosion resistance of the Mg films was affected by surface morphology and crystal structure. The corrosion resistance of the Mg coated HDA specimen increased with decreasing crystal size of the Mg coating and it was also improved by forming a film with denser morphology. The crystal structure oriented at Mg(101) plane showed the best corrosion resistance among crystal planes of the Mg metals, which is attributed to its relatively low surface energy. Neutral salt spray test confirmed that corrosion resistance of HDA can be greatly improved by Mg coating, which is superior to that of HDG (hot dip galvanized steel). The reason for the improvement of the corrosion resistance of Mg films on hot dip aluminized steel was due to the barrier effect by the Mg corrosion products formed by the corrosion of the Mg coating layer.

• Journal of Plant Biotechnology
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• v.32 no.2
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• pp.105-109
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• 2005

To enhance salidroside productivity from a cell suspension cultures of Rhodiola sachalinensis, various combinations of auxin (NAA) and cytokinins (BA, Kinetin) concentration and addition of $GA_3$, TDZ, zeatin, spermine and spermidine at a hormone combination to be established were examined. NAA/BA combination is superior to NAA/kinetin combination in biomass and salidroside content. Maximum salidroside production ($64.6{\pm}8.9\;mg/L$ medium) was obtained from $2B_5$ medium with 1 mg/L NAA and 5 mg/L BA. The adding of $GA_3$ ($0.01\;mg/L{\sim}5\;mg/L$) was beneficial for salidroside accumulation and the highest productivity of salidroside, $90.3{\pm}8.34\;mg/L$, was obtained from $2B_5$ medium supplemented with 1 mg/L NAA, 5 mg/L BA and 0.1 mg/L $GA_3$. On TDZ, zeatin, spermine and spermidine, expectant results were not obtained except a little affirmative effect of spermidine ($69{\pm}2.88$ at 1 mg/L).