• Journal of Pharmaceutical Investigation
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• v.10 no.4
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• pp.23-29
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• 1980

Ampicillin-polyvinylpyrrolidone coprcipitates, 1 : 5 ratio w/w, were prepared by the solvent method to increase the solubility and dissolution rate of ampicillin anhydrous. It was found that the solubility and dissolution rate of the coprecipitate were higher than that of ampicillin anhydrous, mechanical mixture of ampicillin and polyvinylpyrrolidone in powder state. The intrinsic, dissolution rate, G, are $1.15{\times}10^{-4}\;mole\;cm^{-2}\;min^{-1}$ for the coprecipitate, $1.09{\times}10^{-5}\;mole\;cm^{-2}\;min^{-1}$ for ampicillin anhydrous, and the activation energy of the coprecipitate and ampicillin anhydrous are $9.091{\times}10^3cal/mole$ and $1.854{\times}10^3cal/mole$, respectively.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.910-916
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• 2009

Present work was focused on the influence of methylcellulose (MC) on steady rheology of wheat gliadin solution and the properties of glycerol plasticized gliadin films. The presence of MC below 0.99 wt% improved viscosity and flow activation energy of the 10 wt% gliadin solution significantly. In the casting films containing 0.2 g glycerol/g dry protein, the MC component aggregated in the gliadin matrix. The blend films containing less than 7.7 wt% MC exhibited higher Young's modulus (E) and tensile strength (${\sigma}_b$) and lower elongation at break (${\epsilon}_b$) in comparison with the pure gliadin film, which was related to the intermolecular interaction between MC and gliadins, the brittle fracture of the aggregated MC component, and the increase in glass transition temperature ($T_g$) of the gliadin phase. Increasing MC content led to a slight increase in water vapor permeability (WVP) without significant influence on the moisture absorption (MA).

• Structural Engineering and Mechanics
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• v.17 no.3_4
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• pp.303-329
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• 2004

Magnetostrictive materials are routinely employed as actuator and sensor elements in a wide variety of noise and vibration control problems. In infrastructural applications, other technologies such as hydraulic actuation, piezoelectric materials and more recently, magnetorheological fluids, are being favored for actuation and sensing purposes. These technologies have reached a degree of technical maturity and in some cases, cost effectiveness, which justify their broad use in infrastructural applications. Advanced civil structures present new challenges in the areas of condition monitoring and repair, reliability, and high-authority actuation which motivate the need to explore new methods and materials recently developed in the areas of materials science and transducer design. This paper provides an overview of a class of materials that because of the large force, displacement, and energy conversion effciency that it can provide is being considered in a growing number of quasistatic and dynamic applications. Since magnetostriction involves a bidirectional energy exchange between magnetic and elastic states, magnetostrictive materials provide mechanisms both for actuation and sensing. This paper provides an overview of materials, methods and applications with the goal to inspire novel solutions based on magnetostrictive materials for the design and control of advanced infrastructural systems.

• Journal of Welding and Joining
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• v.33 no.6
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• pp.42-48
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• 2015

Reduced activation ferritic/martensitic steels are recognized as the primary candidate structural materials for fusion blanket systems. Welding is an inevitable for breeding blanket for pressure tightness and radioisotope confinement. Especially, TIG welding was chosen for sealing because it has the largest gap allowance compared to the other welding methods, and its properties are controllable by feed wire and welding conditions. In this study, the low cycle fatigue test using two-type gage such as extensometer and strain gage was applied to the TIG welded joint of F82H steel, for evaluating fatigue damage accumulation behavior of the HAZs. As the result, the over-tempered HAZ have shown a higher fatigue damage accumulation compared with other materials at all the testing conditions.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.715-719
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• 2000

It is reported that we are facing the serious environment pollution difficulties such as acid rain, green house effects, etc. The gaseous matter CO, NOx, SOx, VOCs which are regarded as main factors for these current pollutions are mainly emitted from power plants and vehicles. Therefore several leading countries are regulating the related laws strictly, especially exhaust emissions from a Diesel engine without an after treatment device. The Objective of this study is to find out NOx removal characteristics focused on emissions of a Diesel engine using radical at each engine speed and load. It is generated from outer air and put into a mixing chamber in the end of exhaust line. In addition, the optimum temperature condition to activate reaction by radical is experimentally carried out. Concentration of exhaust emissions is analyzed from the gas anlayzer(KaneMay) and FTIR to estimate by-products.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1199-1204
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• 2003

The 3D simulations of the shielding concrete and the Rotary Specimen Rack(RSR) in the Korea Research Reactor-1&2(KRR-1&2) were carried out in present work. Four main dismantling processes, which are the removal of the RSR, reactor core region, beam tube, and thermal column and activated concrete, were selected for the graphic simulation by the consideration of the activation, worker training, work difficulty and so on. On the basis of these, we constructed their 3D CAD models and then drawn and reviewed their dismantling processes. In this study, the 3D simulation results of the shielding concrete and the RSR among main components are also presented and discussed.

• Journal of Engineering Education Research
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• v.18 no.6
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• pp.38-45
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• 2015

This study aims to conduct a case study of the Science, Technology, Engineering, Arts, and Mathematics (STEAM) outreach program development and their application. This program was operated by 184 middle and high school students at C University on October 2014. The major results of these studies were as follows: First, The theme of the outreach program consisted of four engineering areas, aerospace engineering, chemical engineering, architectural engineering, and mechatronics (robot) engineering; moreover, the materials for the students' workbook, the guidebook for teachers, and the program operation manual for staffs in a university were developed by working with four authors and ten subject matter experts. Second, the satisfaction level with the contents and activities was ranged from 4.24-4.31 out of 5 points. Third, the vitalizing activation plan was discussed for the sustainable development and operation of the STEAM outreach program.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.3
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• pp.177-182
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• 1986

The dynamic mechanical properties of milk gel were examined as function of temperature, concentrations of milk and enzyme. The real and imaginary parts of the complex rigdity G' and G' were measured at $2\%$ strain and 5 rad/s of frequency. The results showed that the rigidity of milk gel was dependent on the concentration of milk (C) in such a way that $\sqrt{G'}{\propto}C$. It was found that gel point ($t_g$) was dependent on the concentration of milk as $t_g{\propto}C$, and on the concentration of enzyme as $t_g{\propto}\;1/(E)$, The activation energy of enzymatic reaction stage and coagulation stage were $21.1{\pm}5.8\;kcal/mol$ and $26.4{\pm}1.14\;kcal/mol$, respectively.

• Journal of Powder Materials
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• v.23 no.2
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• pp.170-176
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• 2016

Lithium-ion batteries (LIBs) are rapidly improving in capacity and life cycle characteristics to meet the requirements of a wide range of applications, such as portable electronics, electric vehicles, and micro- or nanoelectro-mechanical systems. Recently, atomic layer deposition (ALD), one of the vapor deposition methods, has been explored to expand the capability of LIBs by producing near-atomically flat and uniform coatings on the shell of nanostructured electrodes and membranes for conventional LIBs. In this paper, we introduce various ALD coatings on the anode, cathode, and separator materials to protect them and improve their electrochemical and thermomechanical stability. In addition, we discuss the effects of ALD coatings on the three-dimensional structuring and conduction layer through activation of electrochemical reactions and facilitation of fluent charge collection.

• Journal of the Korean Ceramic Society
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• v.26 no.4
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• pp.499-504
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• 1989

Coloring effect, mechanical properties resulting from silver ions exchange of glasses immersed into the mixed molten salt of KNO3 and AgNO3 were investigated in this study. Ion exchange coloring of glasses made it possible to obtain glasses with a range from yellow to yellowish-brown, and spectral transmittance was investigated. The amount of ion exchange and peneration depth increased with treatment temperature and time. The activation energy decreased with mole fraction of AgNO3. It can be seem that the bending strength of ion exchanged glasses were 3~4 times higher than the parent glass and Ag+ colloids prevented from increasing surface microhardness.