• The Journal of Korean Academy of Prosthodontics
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• v.38 no.5
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• pp.704-723
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• 2000

This study was undertaken to evaluate the tensile bond strength of In-Ceram alumina core treat-ed by ion assisted reaction(IAR). Ion assisted reaction is a prospective surface modification technique without damage by a keV low energy ion beam irradiation in reactive gas environments or reactive ion itself. 120 In-Ceram specimens were fabricated according to manufacturer's directions and divided into six groups by surface treatment methods of In-Ceram alumina core. SD group(control group): sandblasting SL group: sandblasting + silane treatment SC group: sandblasting + Siloc treatment IAR I group: sandblasting + Ion assisted reaction with argon ion and oxygen gas IAR II group: sandblasting + Ion assisted reaction with oxygen ion and oxygen gas IAR III group: sandblasting + Ion assisted reaction with oxygen ion only For measuring of tensile bond strength, pairs of specimens within a group were bonded with Panavia 21 resin cement using special device secured that the film thickness was $80{\mu}m$. The results of tensile strength were statistically analyzed with the SPSS release version 8.0 programs. Physical change like surface roughness of In-Ceram alumina core treated by ion assistad reaction was evaluated by Contact Angle Measurement, Scanning Electron Microscopy, Atomic Force Microscopy; chemical surface change was evaluated by X-ray Photoelectron Spectroscopy. The results as follows: 1. In tensile bond strength, there were no statistically significant differences with SC group, IAR groups and SL group except control group(P<0.05). 2. Contact angle measurement showed that wettability of In-Ceram alumina core was enhanced after IAR treatment. 3. SEM and AFM showed that surface roughness of In-Ceram alumina core was not changed after IAR treatment. 4. XPS showed that IAR treatment of In-Ceram alumina core was enabled to create a new functional layer. A keV IAR treatment of In-Ceram alumina core could enhanced tensile bond strength with resin cement. In the future, this ion assisted reaction may be used effectively in various dental materials as well as in In-Ceram to promote the bond strength to natural tooth structure.

• Progress in Superconductivity and Cryogenics
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• v.18 no.4
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• pp.35-39
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• 2016

In recent years, high-temperature superconductor (HTS) Quadruple Triplets are being developed for heavy ion accelerators, because the HTS magnets are suitable to withstand radiation and high heat loads in the hot cell of accelerators. Generally, an iron yoke, which costs a mass of material, was employed to enhance the magnetic field when a quadrupole magnet was designed. The type of the magnet is called iron-dominated magnet, because the total magnetic field was mainly induced by the iron. However, in the HTS superconductor iron-dominated magnets, the coil-induced field also can have a certain proportion. Therefore, the air-core HTS quadrupole magnets can be considered instead of the iron-core HTS quadrupole magnet to be employed to save the iron material. This study presents the design of an air-core HTS quadruple triplet which consists three by air-core HTS quadruple magnet and compare the design result with that of an iron-core HTS quadruple triplet. First, the characteristics of an air-core HTS quadrupole magnet were analyzed to select the magnet system for the magnetic field uniformity impairment. Then, the field uniformity was improved(< 0.1%) exactly using evolution strategy (ES) method for each iron-core HTS quadrupole magnet and the air-core HTS quadruple triplet was established. Finally, the designed air-core triplet was compared with the iron-core HTS quadruple triplet, and the results of beam trajectories were presented with both the HTS quadruple triplet systems to show that the air-core triplet can be employed instead of the iron-core HTS triplet. The design of the air-core quadruple triplet was suggested for a heavy ion accelerator.

• Journal of Ceramic Processing Research
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• v.13 no.spc2
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• pp.363-367
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• 2012

DLC (diamond liked carbon) coating of the tungsten carbide (WC) alloy core surface for molding a glass aspheric lens improves the quality of glass lens and the molding core and is characterized by high hardness, high elasticity, abrasion resistance and chemical stability. In this study, the effect of DLC coating of a thin film by means of the filtered AIP (arc ion plating) technique was examined on Ra and shape of the coated surface. Roughness before and after DLC coating was measured and the result showed that the roughness was improved after coating as compared to before coating. It was observed that DLC coating of the WC alloy core surface for molding had an effect on improving the roughness and shape of the core surface. It is considered that this will have an effect on improving abrasion resistance and the service life of the core surface.

• Macromolecular Research
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• v.16 no.1
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• pp.21-30
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• 2008

Based on the sheath-core bicomponent composite fibers with modified polystyrene (PS) and the modified polypropylene (PP), composite fibers obtained were further cross-linked and sulphonated with chlorosulphonic acid to produce strong acidic cation ion exchange fibers. The structures of the fibers obtained were characterized using Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) etc. The optimal technology of the fibers obtained is discussed. The static absorption capacity of the sheath-core bicomponent composite cation exchange fibers for $Zn^{2+}$, $Cu^{2+}$ was determined. The absorption kinetics and major factors affecting the absorption capacities of $Zn^{2+}$, $Cu^{2+}$ were studied, and its chemical stability and regenerating properties were probed. The results suggest that cation exchange fibers with better mechanical properties and higher exchange capability were obtained. Moreover, this type of ion exchange fiber has good absorption properties and working stability to various metal ions. Hence, they have higher practicability.

• Bulletin of the Korean Chemical Society
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• v.27 no.9
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• pp.1453-1455
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• 2006

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.503-508
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• 2001

With difference to strengthening which could be evaluated structural efficiency, it is hard to do quantitative repair efficiency evaluation achieved compressive strength test or appearance investigation. In this paper, chloride ion penetration test is exacted to core specimens picked from repaired structure for quantitative repair evaluation. The result of experimentation shows repair efficiency quantitatively by means of difference between penetration amount of chloride ion for repaired and unrepaired core specimens.

• Journal of Technologic Dentistry
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• v.32 no.4
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• pp.351-356
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• 2010

Purpose: The purpose of this study was to evaluate the fracture strength between the core and veneering ceramic according to 2 core materials, In-Ceram Alumina and In-Ceram Zirconia, fabricated by electro ceramic layering technique. 2 different fixed partial denture cores of three units were veneered by veneering ceramic(Ceranion, Noritake) (n=10). Methods: The fracture strengths between the core and veneering ceramic were measured through the 3 point bending test. The interfaces between the core and veneering ceramic were observed with the X-ray dot mapping of EPMA. Results: The result of fracture strength was observed that IZP group, In-Ceram Zirconia core, had higher fracture strength. IPA group, In-Ceram Alumina core, had fracture strength of 359.9(${\pm}$86.2) N. IZP group, In-Ceram Zirconia core, had fracture strength of 823.2(${\pm}$243.0) N. X-ray dot mapping observation showed that a major element in the core and veneering ceramic of IPA group was alumina and silica, respectively. No binder was observed in interfaces between the core and veneering ceramic, and no ion diffusion or transition was observed between the core and veneering ceramic. However, apparent ion diffusion or transition was observed between the core and veneering ceramic of IZP group.

• Journal of Electrochemical Science and Technology
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• v.12 no.1
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• pp.74-81
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• 2021

Silicon (Si) is recognized as a promising anode material for high-energy-density lithium-ion batteries. However, under a condition of electrode comparable to commercial graphite anodes with low binder content and a high electrode density, the practical use of Si is limited due to the huge volume change associated with Si-Li alloying/de-alloying. Here, we report a novel core-shell composite, having a reversible capacity of ~ 500 mAh g-1, by forming a shell composed of a mixture of nano-Si, graphite nanosheets and a pitch carbon on a spherical natural graphite particle. The electrochemical measurements are performed using electrodes with 2 wt % styrene butadiene rubber (SBR) and 2 wt.% carboxymethyl cellulose (CMC) binder in an electrode density of ~ 1.6 g cm-3. The core-shell composites having the reversible capacity of 478 mAh g-1 shows the outstanding capacity retention of 99% after 100 cycles with the initial coulombic efficiency of 90%. The heterostructure of core-shell composites appears to be very effective in buffering the volume change of Si during cycling.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.6
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• pp.1-8
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• 2000

A new method of knock detection in SI engines, using a change of ion concentration in the combustion chamber, was developed. In order to measure in-cylinder ionization current, ionization probes were installed at spark plug and cylinder head of production engine. It was found that the electric current generated by ionized gas in core burned gas region of knocking cycle is between 2 and 10 times larger than that of normal cycle, because the burned gas temperature which is the dominant parameter of a change of ion concentration increases. However, a change of ionization current in boundary region of burned gas is relatively weak. Hence a change of ion concentration in core burned gas region can be used for knock detection.

• Nuclear Engineering and Technology
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• v.54 no.6
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• pp.1935-1946
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• 2022

The investigations of the coated-particles of nuclear fuel samples are carried out in three stages: front-end, irradiation in the reactor core, and post-irradiation examination. The front-end stage is the initial analysis of the failures rates of produced samples before they are placed in the reactor core. The purpose of the verification is to prepare the particles for an experiment that will determine the degree of damage to the coated particles at each stage. Before starting experiments with the samples, they must be properly prepared. Polishing the samples in order to uncover the inner layers is an important, initial experimental step. The authors of this paper used a novel way to prepare samples for testing - by applying an ion polisher. Mechanical polishing used frequently for sample preparations generates additional mechanical damages in the studied fuel particle, thus directly affecting the experimental results. The polishing methods were compared for three different coated particles using diagnostic methods such as Raman spectroscopy, scanning electron microscopy, and confocal laser scanning microscopy. Based on the obtained results, it was concluded that the ion polishing method is better because the level of interference with the structures of the individual layers of the tested samples is much lower than with the mechanical method. The same technique is used for the fuel particles undergone ion implantation simulating radiation damage that can occur in the reactor core.