• Journal of Technologic Dentistry
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• v.39 no.1
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• pp.43-52
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• 2017

Purpose: Physical and chemical properties of gold is most suitable to be restored of teeth to its original state. Recently zirconia was used instead of gold because of esthetical and intimacy of human body. Because of high strength and high abrasion resistance of zirconia, all zirconia artificial tooth lead to wear the original tooth of opposite site. To preserve this original tooth, zirconia artificial tooth covered with dental ceramic glass was used. When joining the zirconia core and dental ceramic glass, difference of their thermal expansion coefficient and wetting ability is generated the residual stress at interface lead to crack. In order to solve this problem, intermediate layer what is called zir-liner was imported to decrease the residual stress and increase the bonding strength. Methods: In this study, to identify the optimum conditions for manufacturing process, various methods to rough the surface of zirconia core were adopted, and vary the thickness of interlayer, and analyzed bond strength. Results: Bond strength of sanding specimens group showed higher than that of non-sanding specimens group, and once applied intermediate layer with sanding specimens showed highest bond strength with 28 MPa. SEM photomicrographs of zirconia cores fired at $1500^{\circ}C$ showed parallel straight lines in sanding and pockmarked surface in blasting surfaces as abrasion traces. Observation of the destruction section after shear test by SEM were carried out. Liner applied non-sanding group and non-liner applied sanding group all showed interfacial crack. Sandblasting group with non-liner showed remained dental ceramic glass on the surface of zirconia. Sandblasting group with once applied liner showed partially remained liner and dental ceramic glass on the surface of zirconia. XRD analysis revealed that sandblasting group showed higher monoclinic peaks than other specimens group and this result was due to the high collision energy for stress induced phase transformation. Conclusions: A study on the improvement of bonding strength between zirconia and dental ceramic glass steadily carried out for the future to practical use.

• International Journal of Aeronautical and Space Sciences
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• v.5 no.2
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• pp.71-76
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• 2004

This paper describes the antenna analysis of the multi-beam for communicationsatellite. The design core parameters of the antenna system are optimal antennadiameter, feed horn type and hom size, F/D, and the coordinate of offset horns. Thepaper deals with the method to determine design core parameters of optimal antennadiameter, feed horn type and horn size. F/D, and the coordinate of offset horns, andthe performances of design result.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.871-872
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• 2006

Nowadays the market for diamond tools grows rapidly. The present decline in the price of industrial diamond makes it a commoditised product capable of competing with conventional abrasives. In terms of production volume, the largest group of diamond tools comprises the metal-bonded diamond impregnated tools, such as sawblades, wire saws, and core drills for cutting stone and construction materials, and core bits for mining applications. This article provides a compendious coverage of the powder metallurgy (PM) diamond tool-making routes, and identifies the recent trends towards changing the tool design and composition to render it cheaper and more efficient.

• Bulletin of the Korean Chemical Society
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• v.21 no.6
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• pp.618-622
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• 2000

The '3+1'type condensation of 16-thiatripyrromethane with $N-alkyl-24-bis[(\alpha+hydroxy-\alpha-phenyl)methyl]pvrole$, in the presence of acid catalyst afforded core-modified, N-confused porphyrins bearing alkyl groups at the rim nitrogen. The proton NMR spectra indicate that the bulkiness of the N-alkyl substituents is somewhat relatedwith the tiltedness of the inverted pyrrole ring. The changes in chemical shift of inner methine protons depending on the N-alkyl group and protonation site is discussed.

• Journal of Korean Academy of Nursing Administration
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• v.8 no.4
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• pp.655-667
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• 2002

Purpose : This study analysis of nursing interventions and core nursing interventions performed orthopedic surgery care unit. Method : The data were collected from 55 nurses of 4 general hospital from July. 10, 2002 to Aug. 30, 2002. The instrument for this study was the Korean translation of 486 nursing intervention classifications developed by McColskey & Bulechek in 2000. In the 486 nursing interventions 350 nursing interventions were selected 8 among the 10 more than 5 years working group in orthopedic surgery care unit. Self frequency checking performed by 350 nursing interventions were used secondary questionnaire In the orthopedic surgery care unit nurses. Results : 1. The most frequently used nursing interventions domains were "Physiological : basic" and then "Physiological: complex", "Health system" "Behavior", "Family", "Safety". 2. Orthopedic surgery care unit core nursing interventions were performed several times a day by 50% or more of orthopedic surgery care unit and this result were 4 of domain, 11 of class, 26 core nursing interventions. This core nursing interventions were 5 of "Physiological : basic", 17 of "Physiological: complex", 1 of "Safety", 3 of "Health system" and have no "Behavior", "Family". Conclusion : This study analyzed nursing intervention of orthopedics and reestablished nursing intervention concept and I hope this study will be helpful for the nurse to be a professional by applying this to actual clinic, for development in qualified nursing and for establishment nursing information system.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.126-133
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• 2017

This paper deals with the effects of welding, which is done to fix the stator stack, on a motor in case of fabricating a prototype motor that is manufactured in a small quantity. In the case of a small motor, the stator is designed and fabricated with the segmented core as a way to raise the fill factor of winding wire to the utmost within a limited size. In case of fabrication by welding both inside and outside of the stator in order to fix the segmented-core stator, the effects of stack are ignored, and the eddy current loss occurs. This paper performed the no-load test on an IPM-type BLDC motor for driving the suction fan of a vacuum cleaner, which was manufactured by using a segmented-core stator. As a result of the test, it was found that input power more than expected was supplied. To analyze the effects of welding by using the finite element analysis method and verify them experimentally, a stator was re-manufactured by bonding, and input power supplied during the no-load test was compared.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.93-93
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• 2013

In recent years, multifunctional ternary nitride thin films have received extenstive attention due to its versatility in many applications. In particular, noble metal based ternary nitride thin films showed a promising properties in the application of Multifunctional heating resistor films because its good electrical properties and excellent resistance against oxidation and corrosion. In this study, we prepared multifunctional noble metal based ternary nitride thin films by atomic layer deposition (ALD) and plasma-enhanced ALD (PEALD) method. ALD and PEALD techniques were used due to their inherent merits such as a precise composition control and large area uniformity, which is very attractive for preparing multicomponent thin films on large area substrate. Here, we will demonstrate the design concept of multifunctional noble metal based ternary thin films. And, the relationship between microstructural evolution and electrical resistivity in noble metal based ternary thin films will be systemically presented. The useful properties of noble metal based ternary thin films including anti-corrosion and anti-oxidation will be discussed in terms of hybrid functionality.

• Nuclear Engineering and Technology
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• v.46 no.4
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• pp.513-520
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• 2014

In this paper, three types of operational and industrial absorbers used at research reactors, including Ag-In-Cd alloy, $B_4C$, and Hf are selected for sensitivity analyses. Their integral effects on the main neutronic core parameters important to safety issues are investigated. These parameters are core excess reactivity, shutdown margin, total reactivity worth of control rods, thermal neutron flux, power density distribution, and Power Peaking Factor (PPF). The IAEA 10 MW benchmark core is selected as the case study to verify calculations. A two-dimensional, three-group diffusion model is selected for core calculations. The well-known WIMS-D4 and CITATION reactor codes are used to carry out these calculations. It is found that the largest shutdown margin is gained using the $B_4C$; also the lowest PPF is gained using the Ag-In-Cd alloy. The maximum point power densities belong to the inside fuel regions surrounding the central flux trap (irradiation position), surrounded by control fuel elements, and the peripheral fuel elements beside the graphite reflectors. The greatest and least fluctuation of the point power densities are gained by using $B_4C$ and Ag-In-Cd alloy, respectively.

• Nuclear Engineering and Technology
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• v.17 no.2
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• pp.98-104
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• 1985

A number of reactivity devices are distributed in a CANDU-PHWR core to control the power distribution and excess reactivity. The effects of these devices are represented by incremental cross sections in core analysis. The incremental cross sections are generated by the SUPERCELL code using the two-group constant set calculated by the lattice code, WIMS. The incremental cross sections are then assessed for adjusters and zone controller by core simulation. Reactivity worth and channel powers are compared to the reference values. The deviation of reactivity worth and the maximum channel power are less than 0.97% and 0.6%, respectively, for the initial and equilibrium core.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1061-1062
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• 2007

In this paper, the analysis of some possibilities for increasing the induction motor efficiency is reported. This approach does not require a complete redesign of new laminations with a consistent cost in terms of investments. This paper shows the efficiency of the rectangular core types according to core-cutting-degree and compares the efficiency of the rectangular core types with the round core types. In particular, for obtaining an increase in efficiency, increase of the core axial length has been taken into consideration. The paper shows the results obtained by the finite element method(FEM) and IEEE Std. 112-96 Method B and analyzes the results to get a high efficiency for the induction motor.