• Journal of Korean Society for Atmospheric Environment
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• v.12 no.1
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• pp.43-53
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• 1996

Numerical simulation was performed for the 3-dimensional flow filed of gas and particle phase for cyclone dust collector. FVM(Finite Volume Method) was employed for gas phase. The flow was solved suing the k-.varepsilon. epsilon turbulence model. The particle exit at the bottom of the cone was treated as a solid wall in this model because the gas flow through the effective dust exit is usually insignificant. The major parameters considered in this study was vortex finder diameter, effective dust exit diameterm vortex finder length, inlet type for dimension performance. Particle trajectory calculations were made for three different, particle sizes of 1, 25 and 50 .mu.m. The results obtained from this study give some physical insight of dust particle collection mechanism together with the indication of the collection efficiency. The simulation results were in generally good agreement with empirical knowledge. The application of this kind of computer program looks promising as a potential tool for the design of cyclone and determination of optimum operating condition.

• Journal of Surface Science and Engineering
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• v.12 no.3
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• pp.161-166
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• 1979

Theoretical and practical aspects are investigated for electrochemical behavious, plating processes and the structures of electrodeposit of Pb-Sn binary alloy plating through numerous literatures in this report. The anodic and cathodic electrode reaction mechanisms of Pb and Sn could co-deposit and make Pb-Sn alloy deposit from the results of cathode current density-cathode potential curves of Pb, Sn and Pb-Sn alloys in fluoborate solutions. The compositions of the best alloy plating solutions are obtained for the purpose of bearing, anticorrosion and solder plating. In general, the casting anodes of Pb-Sn alloys are used, but separated anodes of Pb and Sn pure metal are used in order to obtain the fine compositions of Pb-Sn alloy deposits. The electrodeposits of Pb-Sn alloy are in nonequilibrium state and saturated solid solutions. Thus, ${\beta}$-phase (Sn-phase) is precipitated by heat treatment. The texture and structure of the electrodeposit are associated with the surface energies of deposit lattice planes and with the cathode polarization. The electrodeposit of Pb-Sn alloy is shown as lamellar structure.

• KSBB Journal
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• v.20 no.3
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• pp.133-141
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• 2005

This review presents the preparation, transport mechanism and application of molecularly imprinted membranes (MIM). Molecular imprinting has now been established as a technique which allows the creation of tailor-made binding sites for many classes of compounds. MIM have some advantages; a high capacity due to a large surface area, faster transport of substrate molecules and faster equilibrium of binding cavities compared to molecularly imprinted particles. MIM were prepared by covalent and non-covalent chemical bonding systems, by interactions between functional monomer and template. MIM can be prepared by in-situ polymerization, wet phase inversion, dry phase inversion, and surface imprinting method. MIM can continuously separate mixtures based on facilitated or retarded diffusion of the template. MIM can change their permeability in the presence of templates. MIM have a potential to be used to separate chiral compounds and materials with similar structures. However the application of MIM by the chemical industries is still in its infancy stages.

• Steel and Composite Structures
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• v.35 no.4
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• pp.545-554
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• 2020

The present paper explores nonlinear dynamical properties of piezo-magnetic beams based on a nonlocal refined higher-order beam formulation and piezoelectric phase effect. The piezoelectric phase increment may lead to improved vibrational behaviors for the smart beams subjected to magnetic fields and external harmonic excitation. Nonlinear governing equations of a nonlocal intelligent beam have been achieved based upon the refined beam model and a numerical provided has been introduced to calculate nonlinear vibrational curves. The present study indicates that variation in the volume fraction of piezoelectric ingredient has a substantial impact on vibrational behaviors of intelligent nanobeam under electrical and magnetic fields. Also, it can be seen that nonlinear free/forced vibrational behaviors of intelligent nanobeam have dependency on the magnitudes of induced electrical voltages, magnetic potential, stiffening elastic substrate and shear deformation.

• Journal of Magnetics
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• v.16 no.4
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• pp.403-407
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• 2011

Metal-insulator type, nano-granular soft magnetic films have been reviewed from the viewpoint of high frequency magnetic materials. The formation of nano-granular structure is related to the magnitude of heat of formation of intergranule materials. Variation of the ratio of granule phase to intergranule phase in the film is found to produce various characteristics in the magnetic properties of the film. The HRTEM observation reveals that neighboring granules in the film with above 60 at.% Co, contact at considerable points and the films show soft magnetic properties which are explainable in terms of the random anisotropy model for nano-crystalline materials. Addition of Ni group elements in Co-O based films enhances their anisotropy field up to 400 Oe and they exhibit excellent frequency response of permeability. Also, large electromagnetic noise suppression effect is demonstrated as one of their potential applications.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.176-181
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• 2007

The widespread of IT technology caused a remarkable change in many industries and the construction industry is also one of them being influenced in the form of CIC(Computer Integrated Construction) and BIM(Building Information Modeling). Construction projects have many participants from various disciplines involved throughout the entire process. Therefore the success of the project greatly depend on the efficiency of decision-making using the information generated from each process stage. Looking from this aspect, the greatest potential value lies in the planning and pre-design stage when considering the construction life cycle. In this paper, we propose a project on developing a 3D object oriented simulation system for supporting the pre design phase. We define the needs for such system through previous case studies and suggest a to be process model. Finally we anticipate the effects that the project will eventually contribute to the construction industry.

• Journal of the Korea Safety Management & Science
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• v.7 no.1
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• pp.57-76
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• 2005

A standardized ergonomics kit is suggested to evaluate and reduce musculoskeletal hazards that yield large socioeconomic burdens in the work system. This kit comprises basic and detailed analysis tools with proper tool selection rules. The basic tool includes a checklist for various risk factors to screen potentially hazardous jobs among manual works. Selective detailed analysis tools can then be applied to the screened job lists for more quantitative and precise evaluation. The tool selection rules are devised for using the basic and detailed analysis tools in a mutually supplemental way. To validate the standardized ergonomics kit, it was applied to evaluate jobs related to the musculoskeletal hazards in a paper-making industry. Among 101 manual jobs investigated, 44 potential hazardous jobs were screened during basic investigation phase and finally 16 hazardous jobs were identified by the detailed analysis phase. The result provided fairly promising ideas of ergonomic interventions for the hazardous jobs.

• Journal of the Ergonomics Society of Korea
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• v.27 no.1
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• pp.9-19
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• 2008

Work-related musculoskeletal hazards in a paper-making industry were examined to explore ergonomic interventions in a participatory approach for mitigating the hazards. Manual tasks occurred in this paper-making industry were quite different with ordinary assembly industry where individual workers perform certain specified tasks repetitively. Workers used to perform varieties of team-based irregular manual tasks to interact with the facilities. Among 96 manual jobs investigated, 44 potential hazardous jobs were screened during basic investigation phase and finally 16 hazardous jobs were identified by the detailed analysis phase. The major hazardous factors were awkward postures and excessive weights. Possible ways of intervention were developed, reviewed and proposed by an ergonomics team comprised of staffs and engineers from various departments and ergonomics specialist from outside the company. The proposed intervention ideas were evaluated and modified by the workers and union representatives in terms of usability and comfort. Implemented interventions including mechanization, automation, and improvement of tools and equipments provided fairly promising results.

• Bulletin of the Korean Chemical Society
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• v.27 no.12
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• pp.1981-1984
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• 2006

Novel amphiphilic, thermo-responsive polyaspartamides which showed both LCST (lower critical solution temperature), and sol-gel transition were prepared and characterized. The polyaspartamide derivatives were synthesized from polysuccinimide, the polycondensate of aspartic acid monomer, via successive nucleophilic ring-opening reaction by using dodecylamine and N-isopropylethylenediamine (NIPEDA). At the intermediate composition ranges, the dilute aqueous solution exhibited a thermally responsive phase separation due to the presence of LCST. The phase transition temperature was controllable by changing the content of pendent groups. In addition, a physical gelation, i.e. the sol-gel transition was observed from the concentrated solutions, which was elucidated by dynamic viscoelastic measurements. These novel injectable and thermo-responsive hydrogels have potential for various biomedical applications such as tissue engineering and current drug delivery system.

• Solar Energy
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• v.15 no.1
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• pp.39-51
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• 1995

A numerical scheme based on a coordinate transform into stream function-velocity potential is proposed to solve heat and momentum transfer in porous media with phase change. A significant simplification of both computational domain and governing equations can be achieved by the transform. The dispersion term in the flow through porous media, which is important at the phase change interface, can be successfully incorporated into the numerical scheme without introducing any further computational complications.