• The Journal of Korean Academy of Prosthodontics
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• v.33 no.3
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• pp.584-609
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• 1995

The purpose of this study was to evaluate the difference of the galvanic corrosion behaviour of the titanium in contact with gold alloy, silva-palladium alloy, and nickel-chromium alloy using the immersion and electrochemical method. And the effects of galvallit couples between titanium and the dental alloys were assessed for their usefulness as materials for superstructure. The immersion method was performed by measuring the amount of metal elementsreleased by Inductivey coupled plasma emission spectroscopy(ICPES) The specimen of fifteen titanium plates, the five gold alloy, five silver-palladium, five nickel-chromium plates, and twenty acrylic resin plates ware fabricated, and also the specimen of sixty titanium plugs, the thirty gold alloy, thirty silver-palladium, and nickelc-hromium plugs were made. Thereafter, each plug of gold alloy, silver-palladium, and nickel-chromium inserted into the the titanium and acrylic resin plate, and also titanium plug inserted into the acrylic resin plate. The combination specimens uf galvanic couples immersed in 70m1 artificial saliva solution, and also specimens of four type alloy(that is, titanium, gold, silver-palladium and nickel-chromium alloy) plugs were immersed solely in 70m1 artificial sativa solution. The amount of metal elements released was observed during 21 weeks in the interval of each seven week. The electrochemical method was performed using computer-controlled potentiosta(Autostat 251. Sycopel Sicentific Ltd., U.K). The wax patterns(diameter 11.0mm, thickness,in 1.5mm) of four dental casting alloys were casted by centrifugal method and embedded in self-curing acrylic resin to be about $1.0cm^2$ of exposed surface area. Embedded specimens were polished with silicone carbide paper to #2,000, and ultrasonically cleaned. The working electrode is the specimen of four dental casting alloys, the reference electrode is a saturated calmel electrode(SCE) and the ounter electrode is made of platinum plate. In the artificial saliva solution, the potential scanning was carried out starting from-700mV(SCE) TO +1,000mV(SCE) and the scan rate was 75mV/min. Each polarization curve of alloy was recorded automatically on a logrithmic graphic paper by XY recorder. From the polarization curves of each galvanic couple, corrosion potential and corrosion rates, that is, corrosion density were compared and order of corrosion tendency was determined. From the experiments, the following results were obtained : 1. In the case of immersing titanium, gold alloy, silver-palladium alloy, and nickel-chromium alloysolely in the artificial saliva solution(group 1, 2, 3, and 4), the total amount of metal elements released was that group 4 was greater about 2, 3 times than group 3, and about 7.8 times than group 2. In the case of group 1, the amount of titanium released was not found after 8 week(p<0.001). 2. In the case of galvanic couples of titanium in contact with alloy(group 5, 6), the total amount of metal elements released of group 5 and 6 was less than that of group 7, 8, 9, and 10(p<0.05). 3. In the case of galvanic couples of titanium in contact with silver-palladium alloy(group 7, 8), the total amount of metal elements released of group 7 was greater about twice than that of group 5, and that of group 8 was about 14 times than that of group 6(p<0.05). 4. In the case of galvanic couples of titanium in contact with nickel-chromium alloy(group 9, 10), the total amount of metal elements released of group 9 and 10 was greater about 1.8-3.2 times than that of group 7 and 8, and was greater about 4.3~25 times than that of group 5 and 6(p<0.05). 5. In the effect of galvanic corrosion according to the difference of the area ratio of cathode and anode, the total amount of metal elements released was that group 5 was greater about 4 times than group 6, group 8 was greater about twice than group 7, and group 10 was greater about 1.5 times than group 9(p<0.05). 6. In the effect of galvanic corrosion according to the elasped time during 21 week in the interval of each 7 week, the amount of metal elements released was decreased markedly in the case of galvanic couples of the titanium in contact with gold alloy and silver-palladium alloy but the total amount of nickel and beryllium released was not decreased markedly in the case of galvanic couples of the titanium in contact with nickel-chromium alloy(p<0.05). 7. In the case of galvanic couples of titanium in contact with gold alloy, galvanic current was lower than any other galvanic couple. 8. In the case of galvanic couples of titanium in contact with nickel-chromium alloy, galvanic current was highest among other galvanic couples.

• Journal of Acupuncture Research
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• v.17 no.1
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• pp.189-219
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• 2000

To study the effects of anti-cancer, anti-metastasis and immune response improvement effects of aqua-acupuncture with Rubi Fructus infusion solution, we used Rubi Fructus infusion solution(taken by water-alcohol method) put into Chung-wan (CV12) and Chok-Samni(ST36) of BALB/c or C57BL/6 which are corresponding to humanbody. We observed the cytotoxicity, the effect on the expression of MMP-9 gene, the ability to control cancer cell proliferation, change of body weight, surviving number, median surviving time, increase of life span, changes in amount of leukocyte, erythrocyte, platelet, total protein, creatinine, glucose and LDH, weight of spleen, number of pulmonary colony, histological analysis on tissue metastasis of lung and liver, splenic cell proliferation, the expression of cytokine gene, the number of $CD4^+$, $CD8^+$, $CD19^+$ and NK cell, and concluded like this. The results were obtained as follows : 1. Effects of Anti-cancer 1) The cytotoxicity about B16-F10 cell line of $2^0$, $2^{-1}$, $2^{-2}$, $2^{-3}$, $2^{-5}$, $2^{-6}$, $2^{-7}$, $2^{-8}$ diluent groups in Rubi Fructus infusion solution treatment was inhibited significantly, compared with control group. 2) The cytotoxicity about HT1080 cell line of $2^0{\sim}2^{-8}$ diluent groups in Rubi Fructus infusion solution treatment was inhibited significantly, compared with control group. 3) The effect on expression of MMP-9 gene was inhibited significantly in all the sample groups, compared with control group. 4) The effect on the control-ability on the cancer cell proliferation showed cytotoxicity significantly in $2^0$, $2^{-1}$, $2^{-2}$, $2^{-3}$, $2^{-4}$, $2^{-5}$, $2^{-6}$, $2^{-7}$, diluent groups. 2. Effects of Anti-metastasis 1) S-180 cancer cell line transplants in BALB/c mice were inhibited significantly in weight increase in all the sample groups, compared with control group. The surviving number increased in almost sample groups, except one group put into Chok-Samni(ST36) with 20% Rubi Fructus infusion solution treatment group that showed same number of the control group. 2) S-180 cancer cell line transplants in BALB/c mice showed high MST significantly in almost sample groups, compared with control group. But one group put into Chok-Samni(ST36) with 20% Rubi Fructus infusion solution showed low MST than control group. 3) The group injected in vein with B16-F10 cancer cell line in C57BL/6 mice showed increased ILS than control group significantly in anti-metastasis test. 3. Effects of Immune response improvement 1) The group injected in vein with B16-F10 cancer cell line in C57BL/6 mice were increased significantly in the number of leukocyte and glucose, and decreased significantly in the amount of platelet and LDH, compared with control group. However, there's no significant increase or decrease in number of erythrocyte, total protein and creatinine. 2) We couldn't find any significant relation in spleen weight of the sample group. 3) In pulmonary colony, sample group was decreased significantly, compared with control group. 4) Histological analysis of sample group inhivited compared with that of control group in both of lung and liver. 5) In immune system, all the sample groups showed having more relevancy to the effect on splenic cell proliferation than normal group. 6) Cytokine gene increased in almost sample groups, except one group treated with $50{\mu}g/m{\ell}$ Rubi Fructus infusion solution on IL-12. 7) In flow cytometry there's no significant relation in number of $CD8^+$ cell, however, the number of $CD4^+$, $CD19^+$ cell and NK cell in sample group had more relation than in control group. Above the results showed that aqua-acupuncture of Rubi Fructus solution has effects of anti-cancer, and-metastasis and immune response improvement.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.7 s.250
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• pp.833-840
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• 2006

The paper presents a numerical solution to the problem of a hot rigid indenter sliding over a thermoelastic Winkler foundation with a thermal contact resistance at constant speed. It is shown analytically that no steady-state solution can exist for sufficiently high temperature or sufficiently small normal load or speed, regardless of the thermal contact resistance. However the steady state solution may exist in the same situation if the thermal contact resistance is considered. This means that the effect of the large values of temperature difference and small value of force or velocity which occur at no steady state can be lessened due to the thermal contact resistance. When there is no steady state, the predicted transient behavior involves regions of transient stationary contact interspersed with regions of separation regardless of the thermal contact resistance. Initially, the system typically exhibits a small number of relatively large contact and separation regions, but after the initial transient, the trailing edge of the contact area is only established and the leading edge loses contact, reducing the total extent of contact considerably. As time progresses, larger and larger numbers of small contact areas are established, unlit eventually the accuracy of the algorithm is limited by the discretization used.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.330-333
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• 2005

The paper presents a numerical solution to the problem of a hot rigid indenter siding over a thermoelastic Winkler foundation with a thermal contact resistance at constant speed. It is shown analytically that no steady-state solution can exist for sufficiently high temperature or sufficiently small normal load or speed regardless of the thermal contact resistance. However, the steady state solution may exist in the same situation if the thermal contact resistance is considered. This means that the effect of the large values of temperature difference and small value of force or velocity which occur at no steady state can be lessened due to the thermal contact resistance. When there is no steady-state the predicted transient behavior involves regions of transient stationary contact interspersed with regions of separation regardless of the thermal contact resistance. Initially, the system typically exhibits a small number of relatively large contact and separation regions, but after the initial transient the trailing edge of the contact area is only established and the leading edge loses contact, reducing the total extent of contact considerably. As time progresses, larger and larger number of small contact areas are established, until eventually the accuracy of the algorithm is limited by the discretization used.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.5
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• pp.59-65
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• 2009

Adsorption of an oil-proof agent (OPA）onto cellulose fibers during the papermaking process was investigated using UV-Vis spectrophotometry by measuring the OPA concentration decrease in the solution. From the calibration curve, the spectrum were converted to chemical concentrations in solution, from which the amount adsorbed onto the fiber surface could be determined. Thus, it was possible to determine the total amount adsorbed onto the fibers and in solution. Using this approach, we studied the adsorption behavior of the OPA onto the fiber surface and derived its, ${\Gamma}^s_t={\Gamma}^s_{\infty}(1-e^{-k_{\alpha}t})$. The values of the parameters kaand ${\Gamma}^s_{\infty}$ were determined using a mathematic model based on a mass transfer equation. Ultimately, a complete was derived: $Q={\alpha}{\cdot}\sum\limits_{i-1}^m{\pi}d_il_i{\cdot}M_A{\cdot}(1-e^{-k_{\alpha}t})/A_N$.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.738-743
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• 1991

A multiobjective analysis technique was applied for the optimum operation of pumps and reservoirs in service water transmission systems. Three major objectives were identified and assessed on the normally operating service water transmission systems. They are, 1) stability of pump operation; 2) economic point of view in minimizing the energy cost for pumping; 3) reliability in meeting the stochasticaly varying demands. The measures of these objectives were required times of pump on-offs in stability, required total energy cost in economics, and minimum required storage during the operating horizon in reliability. In order to find the best meeting solution to the decision maker, a set of non-dominated solutions which show the tradeoff relationships between the considering objectives were generated. The DM selects the best solution from this explicit tradeoff relationships using his heuristic decision rules or experience. The theory was verified by applying to the Kumi Service Water System. A combined technique of the ${\varepsilon}-constraint$ and the weighting methods was used to generate the nondominated solutions, and the dynamic programming algorithm was applied to find the optimal solution for the discretized multi-objective analysis problems.

• Geotechnical Engineering
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• v.13 no.3
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• pp.5-20
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• 1997

A governing equation of uncoupled three dimensional finite strain theory of consolidation is presented. This equation is suitable for relatively thick layers, possessing large strain, non-linear material property, and variable permeability. A special numerical solution procedure has to be adopted for the finite difference scheme because the solution is not stable in using Forward-Time Centered-Space (FTCS) method and the governing equation is highly non-linear. The solution is capable of predicting settlement with respect to time. The results predicted by the developed method of analysis have been compared with those of experimental tests on different types of highly compressible soils with vertical wick drain. The uncoupled three dimensional finite strain theory of consolidation appears to predict settlement behavior well. A detailed comparison shows good agreement in terms of total settlement, and reasonable agreement with respect to time.

• Textile Coloration and Finishing
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• v.17 no.4 s.83
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• pp.21-26
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• 2005

A combination separation system is composed of three parts, simple microfiltration unit for the pretreatment of real waste IPA, pervaporation unit with plate and frame type module(the effective membrane area 9,040$cm^2$), and simple ultrafiltration unit as a refiner. Utrafiltration module with hollow fiber membrane(MWCO 10,000) used to purify waste aqueous IPA solution. In addition, the flux of $CMPA-K^+$ composite membrane for waste aqueous IPA solution was very steady-state with long experiment time(30 days). And the standard deviation($\sigma$) was 0.152 and then the coefficient of variation($CV\%$)was 10.82 The IPA concentration on the membrane performance using pervaporation module system could be increased from $89.85wt(\%)$ to more than $99.90wt\%$ in about 8hr at operation temperature of $70^{\circ}C$ using the pervaporation module system. Therefore, a combination separation process system of simple filtration and pervaporation was very effective for the purpose of the IPA purification and reuse front industrial electronic components cleaning process.

• Journal of Pharmaceutical Investigation
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• v.15 no.1
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• pp.32-39
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• 1985

Bioavailability studies in guinea pigs and dissolution tests of sustained release capsules of ascorbic acid were investigated comparing with those of solution. The results were as follows; 1. In the dissolution test sustained release capsules released 90% of ascorbic acid after 12 hours, and ascorbic acid in the chewable tablet was dissolved. completely within 10 minutes. 2. In the determination of total ascorbic acid concentration in serum, the area under the curve between 0 and 24 hours $(AUC\;0{\sim}24h)$ ana the maximum serum concentration $(C_{max})$ did not show any significant difference between solution and sustained release capsule. The time to the maximum concentration $(C_{max})$ and the time over $50{\mu}g/ml$ concentration showed significant difference. 3. The time reached to maximum excretion rate $(T_{max})$ in sustained release capsule was longer than that of solution.

• Journal of the Korean Applied Science and Technology
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• v.37 no.2
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• pp.362-373
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• 2020

The purpose of this study is to verify the possibility of applying sports psychological training based on a solution-based short-term counseling approach. the study subject was a total of 8 units as one of the national athletes of Vietthlon. the measurement tools consisted of questionnaires and in-depth consultations, and the pre- and post-changes were measured and compared based on the results of the winter sports competitions. The results of the study showed that the negative thinking of the athletes was reasonable and positive change. Within a short period of time, confidence and competence in performance were improved, and cognitive anxiety was greatly reduced.