• Journal of the Korean Chemical Society
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• v.38 no.7
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• pp.473-479
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• 1994

Tungsten thin film was deposited on p-(100) silicon substrate by using the LPCVD(low pressure chemical vapor deposition) technique. $WF_6$ was used as a source gas for tungsten and $SiH_4$ was used as a reducing gas for $WF_6$. Tungsten thin film was deposited by either SiH4 or Si substrate reduction of $WF_6$ under cold-wall condition and it was deposited by $SiH_4$ reduction of $WF_6$ under hot-wall condition. The crystal structure of deposited thin film under both conditions were identified to be bcc (body centered cubic). The physical and electrical properties of deposited thin films were investigated. The deposited film under hot-wall condition changed to $WSi_2$ film by the annealing under $800^{\circ}C.$ From the experimental results and theoretical considerations, the change of the crystal structure of the thin film by annealing was discussed. $WSi_2$ thin film, which was known to have good compatibility with Si substrate, could be produced under hot-wall condition although the film properties were superior under cold-wall condition.

• Polymer(Korea)
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• v.39 no.3
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• pp.475-479
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• 2015

Droplet distribution of LCP(Vectra 950) and PET blend by repeated extrusion was examined through morphology analysis. Repeated extrusion was respectively proceeded twice and three times with blending condition and droplet distribution of only once extrusion sample showed uniform shape. However, droplet size of twice and three times extrusion samples increased and it was confirmed that droplets were concentrated on the center of specimens. It is thought that this phenomena were due to the compatibility and viscoelastic behavior of LCP/PET blend. Finally, it is thought that fiber manufacturing of different diameter is possible from spinning of repeated extrusion LCP/PET blended chip under same spinning condition.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.579-584
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• 2001

The reinforced concrete(RC) beam is developed cracks because the compression strength of concrete is strong but the tensile strength is weak. The structural strength and stiffness is decreased by reduction of tension resistance capacity of concrete due to the developed cracks. Using the fiber reinforced concrete that is increased the flexural strength and tensile strength at tensile part can enhance the strength and stiffness of concrete structure and decrease the tensile flexural cracks and deflection. Therefore, The reinforced concrete used the fiber reinforced concrete at tensile part ensure the safety and serviceability of the concrete structures. In this study, analytical model of a dual concrete beam that is composed of the normal strength concrete at compression part and the high tensile strength concrete at tensile part is developed by using the equilibrium condition of forces and compatibility condition of strains and is parted into elastic analytical model and ultimate analytical model. Three group of test beam that is formed of one reinforced concrete beam and two dual concrete beams for each steel reinforcement ratio is tested to examine the flexural behavior of dual concrete beams. The comparative study of total nine test beams is shown that the ultimate load of a dual concrete beams relative to the reinforced concrete beams have an increase in approximately 30%. In addition, the initial flexural rigidity, as used here, refer to the slope of load-deflection curves in elastic state is increased and the deflection is decreased.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.3
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• pp.348-352
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• 2004

The mold transformers have been widely used in underground substations in large building and have some advantages in comparison to oil-transformer, that is low fire risk, excellent environmental compatibility, compact size and high reliability. In addition, the application of mold transformer for outdoor is possible due to development of epoxy resin. The mold transformer generally has cooling duct between low voltage coil and high voltage coil. A mold transformer made by one body molding method has been developed for small size and ow loss, but it needs some cooling method because heat radiation between each winding is difficult. The life of transformer is significantly dependent on the thermal behavior in windings. Many transformer designers have calculated temperature distribution and hot spot point by finite element method(FEM) to analyze winding temperature rise. In this paper, The thermal analysis of pole mount mold transformer with one body molding by duct condition is investigated and the test result of temperature rise is compared with simulation data.

• Journal of Industrial Technology
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• v.26 no.B
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• pp.63-71
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• 2006

The concerned object of the construction industry is environment. It is one of the main purposes of today's construction that human can live reasonably in nature. This study is about the fish-road connecting hydraulic structure in the river with nature. Chapter 2, starting with the general investigation about fish-road and helps comprehension for relatively general fish-road such as necessity, establishment purpose, history, study example, relating domestic law, design condition, consideration and form of fish-road. Chapter 3, containing the present condition of fish-road facilities in Gangwon-Do and thoughts of the problems and general countermeasures of existing fish-road. Chapter 4, Having Examined compatibility by amount of flowing water through hydraulic model test in the Ice harbor I-type model. chapter 5, Analyzation and arrangement to efficient establishment plan of fish-road and the result of the hydraulic model experiment to be beaconed a little in forward fish-road study. In the hydraulic model test result, when we suppose establishment of 1~3 in slope of 1/20, could know that applicable drought flow of the river is $0.06{\sim}3.0m^3/sec$ in case of Ice harbor I-type which transforming Ice harbor that was invented as studying project of the Ministry of Environment.

• Nuclear Engineering and Technology
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• v.45 no.1
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• pp.107-114
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• 2013

It is required that the pH of the sump solution should be above 7.0 to retain iodine in a liquid phase and be within the material compatibility constraints under LOCA condition of PWR. The pH of the sump solution can be determined by conventional chemical equilibrium constants or by the minimization of Gibbs free energy. The latter method developed as a computer code called SOLGASMIX-PV is more convenient than the former since various chemical components can be easily treated under LOCA conditions. In this study, SOLGASMIX-PV code was modified to accommodate the acidic and basic materials produced by radiolysis reactions and to calculate the pH of the sump solution. When the computed pH was compared with measured by the ORNL experiment to verify the reliability of the modified code, the error between two values was within 0.3 pH. Finally, two cases of calculation were performed for the SKN 3&4 and UCN 1&2. As results, pH of the sump solution for the SKN 3&4 was between 7.02 and 7.45, and for the UCN 1&2 plant between 8.07 and 9.41. Furthermore, it was found that the radiolysis reactions have insignificant effects on pH because the relative concentrations of HCl, $HNO_3$, and Cs are very low.

• Special Issue of the Society of Naval Architects of Korea
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• 2005.06a
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• pp.15-21
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• 2005

In this paper, the procedure of generation and application of nonlinear wave loads for structural design of large container carrier was described. Ship motion and wave load was calculated by modified strip method. Pressure acting on wetted hull surface was calculated taking into account of relative hull motion to the wave. Design wave height was determined based on the most sensitive wave length considering rule vertical wave bending moment at head sea or fellowing sea condition. And the enforced heeling angie concept which was introduced by Germanischer Lloyd (GL) classification had been used to simulate high torsional moment in way of fore hold parts similar to actual sea going condition. Using wave load generated from this dynamic load calculation, FE analyses were performed. With this result, yielding, buckling, hatch diagonal deflection and fatigue strength of hatch corners were reviewed based on the requirement of GL classification. The results of FE analysis show good compatibility with GL classification.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1135-1138
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• 2003

The transformer is major equipment in power receiving and substation facilities. Necessary conditions required for the transformer are compactness, lightness, high reliability, economic advantages, and easy maintenance. The pole-mount transformer installed in distribution system is acting direct role in supply of electric power and it is electric power device should drive for long term. Most of modem transformer are oil-filled transformer and accident is happening considerable. The mold transformers have been widely used in underground substations in large building and have some advantages in comparison to oil-transformer, that is low fire risk, excellent environmental compatibility, compact size and high reliability. In addition, the application of mold transformer for outdoor is possible due to development of epoxy resin. The mold transformer generally has cooling duct between low voltage coil and high voltage coil. A mold transformer made by one body molding method has been developed for small size and low loss. One body molding transformer needs some cooling method because heat radiation between each winding is difficult. In this paper, The thermal analysis of pole mount mold transformer with one body molding by duct condition is investigated and the test result of temperature rise is compared with simulation data.

• Structural Engineering and Mechanics
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• v.81 no.4
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• pp.443-459
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• 2022

The paper studies the dispersion and attenuation of propagating waves in the "plate+compressible viscous fluid layer" system in the case where the fluid layer flow is restricted with a rigid wall, and in the case where the fluid layer has a free face. The motion of the plate is described by the exact equations of elastodynamics and the flow of the fluid by the linearized Navier-Stokes equations for compressible barotropic Newtonian viscous fluids. Analytical expressions are obtained for the amplitudes of the sought values, and the dispersion equation is derived using the corresponding boundary and compatibility conditions. To find the complex roots of the dispersion equation, an algorithm based on equating the modulus of the dispersion determinant to zero is developed. Numerical results on the dispersion and attenuation curves for various pairs of plate and fluid materials under different fluid layer face conditions are presented and discussed. Corresponding conclusions on the influence of the problem parameters on the dispersion and attenuation curves are made and, in particular, it is established that the change of the free face boundary condition with the impermeability condition can influence the dispersion and attenuation curves not only in the quantitative, but also in the qualitative sense.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.1
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• pp.1-12
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• 1994

This paper deals with the time-dependent analysis of reinforced and prestressed concrete beams. Based on the age-adjusted effective modulus method, the structural behavior in accordance with time is analyzed using the force equilibrium and strain compatibility condition within a typical section. Unlike most of presented approaches adopting some assumptions, such as non-cracking of concrete and consideration of steel effect as a transformed concrete area only, more accurate results can be obtained at all loading conditions since all materials are considered together so as to be maintained their given properties and the cracking effect is included at the same time. Several parameter studies are conducted with the objective to identify the significance of various effects on the time-dependent response of concrete members, i.e., stress re-distribution of each material and occurrance of long-term deflection, etc. Moreover, the obtained results can be used at design and/or construction stage for the purpose of more accurate prediction of structural response with time.