• Progress in Superconductivity
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• v.4 no.2
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• pp.176-179
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• 2003

A lot of efforts have been focused on the optimization of PIT parameters for Bi-2223/Ag wire. Bi-2223 superconducting wires with 55 filaments were fabricated by stacking, drawing process. Before rolling process, round wires were pre -annealed at 760 - 820 $^{\circ}C$ and low oxygen partial pressure. We confirmed that pre-annealing step was to transform Bi-2212 orthorhombic structure from Bi-2212 tetragonal structure and to reduce the formation of second phases. However Bi-2223 phases also were formed at higher than 76$0^{\circ}C$ of pre-annealing temperature. The engineering critical current densities (Je) of Bi-22231Ag tapes were sintered at low oxygen partial pressure were higher than t hat of the wires sintered at air. We could achieve 6500 A/${cm}^2$ of Je for the tape that was initially kept at slightly higher temperature than that of normal heat treatment.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.197-203
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• 1999

Stainless steels in general has passive film having strong corrosion resistance on surface. Therefore it must be necessarily removed by etching in mixing solution of sulfuric and chloric acid before Nitriding treatment. But in the ion nitriding, nitride layer was easily formed because passive film was removed without difficult by sputtering effect. The removal extent of these passive films was greatly effected by gas mixing ratios and pressure and holding times of pre sputtering factors in pre sputtering stage. As a results of experiment it has been known that pre sputtering pressure and holding time was not nearly effective on the formation behavior of nitride layer. But when A/H2 gas mixing ratios was 1/2 (vol%) was the most effective of the all pre sputtering conditions. It was resulted from the combination of mechanical reaction byArgon bombardment and chemical reaction by reduction of hydrogen on the passive film.

• Korean Journal of Community Nutrition
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• v.18 no.6
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• pp.626-643
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• 2013

This study was performed to evaluate the differences in blood pressure, sodium intake and dietary behavior changes according to the extent of session attendance on sodium reduction education program for pre-hypertensive adults in a public health center. Sodium reduction education program consisted of 8 sessions for 8 weeks. Fifty three patients who completed the pre and post nutritional assessments were classified into 2 groups according to the session attendance rate. Nineteen participants who attended the education program 3 times or less (${\leq}3$) were categorized into the less attendance (LA) group and 34 participants attended 4 times or more (${\geq}4$) into the more attendance (MA) group. Blood pressure, anthropometric measurements, serum lipid profile, nutrient intakes including sodium, nutrition knowledge and dietary behavior score were assessed before and after the nutrition education program. Mean sodium intakes (p<0.001), systolic/diastolic blood pressure (p<0.001), and weight (p<0.001) were significantly decreased in the MA group after sodium reduction education program. Compared to the MA group, mean sodium intakes, systolic/diastolic blood pressure were not significantly changed after the education program even with significantly increased nutrition knowledge (p<0.05) and dietary behavior score (p<0.01) in the LA group. It appears that pre-hypertensive adults need to attend the sodium reduction education program for at least 4 times or more to gain beneficial effects from the intervention. Positive feedback of healthcare team or offering more cooking classes may be needed to raise the attendance rate in the sodium reduction education program.

• Journal of International Academy of Physical Therapy Research
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• v.11 no.2
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• pp.2042-2051
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• 2020

Background: Many trials have been conducted the methods and types of intervention of form rollers, but no research has been done yet that mixes the methods and types of intervention. Objectives: To analyze the effects of myofascial release on the improvement of range of motion (ROM), flexibility, pain pressure threshold, and balance. Design: Randomized controlled trial. Methods: All subjects measured ROM, flexibility, pressure pain threshold, and dynamic balance by pre-test. After pre-test, subjects were randomized that static-vibration foam rolling group (n=12), dynamic-vibration foam rolling group (n=12), general foam rolling group (n=12). For the intervention, 3 sets of 90 seconds were applied to each group, and rest time was set to 60 seconds between sets. In the post-test and follow-up test after 10 minutes, all three groups were measured the ROM, flexibility, pressure pain threshold, and dynamic balance. Results: The results of comparing ROM, flexibility, pressure pain thresholds, dynamic balance ability appeared higher significant difference in the pre-post-10 minutes follow up test in comparison between time in the intragroup (P<.001). As a result of comparing the change of pre-post-10 minutes follow up, static vibration foam rolling showed higher significant difference compared to control groups (P<.001). Conclusion: Through this study, when foam rolling is applied within the same intervention time, static foam rolling can be expected to have a better effect than the existing dynamic foam rolling as well as vibration foam roller can expect better effect than general foam rolling.

• Journal of the Korean Society of Safety
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• v.31 no.5
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• pp.102-108
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• 2016

This paper presents a new strength method of underground box structures under additional surface load. An L-bracing using pre-flexed steel member threads called the "Pre-flex strength method" is used to improve capacity of the RC box structure under earth pressure due to additional surface load. The pre-flexed steel member is fixed the top and bottom of the structure after chemical anchor was installed by drilling hole on the box structure. The structural performance was evaluated analytically. 3 types of underground RC box structure were used; $2.0m{\times}2.0m$, $3.0m{\times}3.0m$ and $4.0m{\times}4.0m$. For the performance evaluation, structure analysis were performed on moment and shear resisting structures with and without pre-flex strength method. Numerical results confirmed that the proposed strength member system installed on underground RC box structures enhanced the strength capacity. The feasible region of the proposed pre-flex strength method in accordance with the earth pressure due to additional surface depth was evaluated.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.5
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• pp.588-597
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• 2004

In this research, we investigated the variation of transmembrane pressure and permeate water quality with pre coagulation and sedimentation with iron based coagulant and chlorination of feed water for PVDF (polyvinylidene fluoride) based MF membrane filtration. NaCIO was fed to the membrane module with dosage of 0.5mg/L and maintained during filtration. To observe the effect of raw water, three types of raw and processed waters, including river surface water, coagulated water and coagulated-settled water, were applied. In case of river surface water, the transmembrane pressure increased drastically in 500 hours of operation. On the contrary, no significant increase in transmembrane pressure was observed for 1,200 hours of operation for coagulated water and coagulated-settled waters. The turbidity of permeate was lower than a detection limit of equipment for all raw waters. The removal efficiency of humic substances of coagulated water and coagulated-settled water was approximate ten times of that of surface river water. And, the removal efficiency of TOC and DOC was approximate two times of that of surface river water. From the results of plant operation, stable operation was maintained at $0.9m^3/m^2{\cdot}day$ filtration flux through the combination of pre-coagulation and pre-chlorination. However, the water quality of permeate was the best when pre-coagulation-sedimentation process was combined with pre-chlorination.

• Nuclear Engineering and Technology
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• v.30 no.5
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• pp.396-402
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• 1998

Experiments on the steamside corrosion and hydrogen pick-up of Zircaloy-4 under high pressure up to 10.3MPa are carried out to estimate the pressure effects on the kinetics. Temperature and reaction time are determined to be 37$0^{\circ}C$ and 72hours for the pre-transition test and $700^{\circ}C$ and 210minutes for the post-transition test, respectively. Results show that under 10.3MPa pressure the oxidation reaction is 50% and 100% enhanced in the pre-and the post-transition regime, respectively. Total amount of hydrogen uptake in the reaction is proportionally increased as corrosion weight gain is elevated. However, pick-up fraction is not affected by the high pressure. The fraction is almost twice greater than that in the waterside corrosion. Edges in the specimens play a certain role in the enhancement, especially in the post-transition regime. To identify physical property changes of oxide film such as micro-cracks or micro-pores, careful and thorough examination must be needed with some special techniques.

• The Journal of Internal Korean Medicine
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• v.30 no.2
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• pp.298-305
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• 2009

Objectives: The present study was carried out to investigate the effects of Yupoongyangyeong-tang(YYT) on changes of regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP) in rats. In addition, the author also investigated action mechanisms of YYT on changes in rCBF and MABP. Methods and Results : In this study, treatment with YYT elevated rCBF in a dose-dependent manner, but MABP levels were elevated only in the 10 mg/ml treatment group. Pre-treatment with indomethacin. an inhibitor of cyclooxygenase, inhibited increase of rCBF effectively. Pre-treatment with methylene blue, an inhibitor of guanylate cyclase, inhibited increase of rCBF induced by YYT, too. In addition. pre-treatment with indomethacin also inhibited increase of MABP. However, pre-treatment with methylene blue did not affect MABP levels. Conclusion : These results suggest that YYT is useful to treat patients with diseases related to cerebral ischemia, because YYT can increase rCBF. In addition, the mechanisms are thought to be related to both cyclooxygenase and guanylate cyclase.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.6
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• pp.61-69
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• 2000

Indium-Tin Oxide (ITO) films were prepared on the commercial glass substrate by the Magnetron Sputtering method. The target was a 90wt.% $In_2O_3$-10wt.% $SnO_2$with 99.99% purity. The ITO films deposited by changing the partial pressure of oxygen gas ($O_2$/(Ar+$O_2$)) of 2, 3 and 5% as well as by changing the substrate temperature of $300^{\circ}C$ or $500^{\circ}C$. The influence of substrate pre-annealing and pre-cleaning on the quality of ITO film were examined, in which the substrate temperature was $500^{\circ}C$ and oxygen partial pressure was 3%. The characteristics of films were examined by the 4-point probe, Hall effect measurement system, SEM, AFM, Spectrophotometer, and X-ray diffraction. The optimum ITO films have been obtained when the substrate temperature is $500^{\circ}C$ and oxygen partial pressure is 3%. At optimum condition, the film showed transmittance of 81%, sheet resistivity of $226\Omegatextrm{cm}^2$, resistivity($\rho$) of $5.4\times10^{-3}\Omega$cm, carrier concentration of $1.0\times10^{19}cm^{-3}$, and carrier mobility of $150textrm{cm}^2$Vsec. From XRD spectrum, c(222) plane was dominant in the case of substrate temperature at $300^{\circ}C$, without regarding to oxygen partial pressure. However, in the case of substrate temperature at $500^{\circ}C$, c(400) plane was grown together with c(222) plane, only for oxygen partial pressure of 2 and 3%. In both case of chemical and ultrasonic cleaning without pre-annealing the substrate, it showed much almost same sheet resistivity, resistivity($\rho$), transmittance, carrier concentration, and carrier mobility. In case of $500^{\circ}C$/60min pre-annealing before ITO film deposited, both transimittance and carrier mobility are better than no pre-annealing, because pre-annealing is supposed to remove alkari ions diffusion from substrate. ITO film deposited on the Corning 0080 sybstrate showed a little bit better sheet resistivity, resistivity($\rho$), transimittance, carrier concentration than the film deposited on commercial glass. But no differences between Corning substrate and pre-annealed commercial glass substrate are found.

• Progress in Superconductivity and Cryogenics
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• v.5 no.1
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• pp.31-34
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• 2003

Bi-2223 superconducting wires with 55 filaments were fabricated by stacking, drawing process with different heat-treatment histories. Two kinds of powders were prepared. One was pre-annealed at 760-820 $^{\circ}C$ and low oxygen partial pressure, and the other was only calcined state. Before rolling process, round wires were pre-annealed at 760 -820 $^{\circ}C$ and in a low oxygen partial pressure. We confirmed that pre-annealing step was to transform Bi-2212 orthorhombic structure from Bi-2212 tetragonal structure and to reduce the formation of second phases at superconducting wire. However Bi-2223 phases were formed at higher pre-annealing temperature. Bi-2223 conductor was needed frequently annealing at low temperature because pre-annealing at precursor powder brought about decrease in workability. We could achieve highest Je of 6500 A/$\textrm{cm}^2$ at the tape using Bi-2212 orthorhombic phase by introduced slightly overheating at the 1st sintering process.