• Composites Research
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• v.29 no.5
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• pp.262-268
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• 2016

In this work, the pitch-based carbon paper (P-CP) was prepared by re-impregnating of binder pitches and PAN-based milled carbon fibers (MCF) at low temperature carbonization process. The influence of MCF content on physicochemical properties of MCF/P-CP was investigated. As a result, the tensile strength of MCF/P-CP was increased sharply from 10 wt.% to 20 wt.% of MCF. Also, the increase of MCF content led to the decrease of interfacial contact resistivity and the improvement of electrical and thermal conductivity of MCF/P-CP. These results were probably due to the increase of density of MCF/P-CP, resulting in the formation of electrically and thermally conductive paths of the carbon paper.

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.289-302
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• 1995

The purpose of this study was to estimate the shear bond strength and observe the fractured and interfacial surfaces of various dentin bonding agents used conjunction with a visible light cured composite. The senentytwo human premolars and molars extracted due to periodontal or orthodontic reasons were used and randomely divided into six groups. All the prepared dentin surfaces were treated with Superbond D-liner, Scotchbond Multi-Purpose, All-Bond 2 and Prisma Universal Bond 3 accroding to the manufacturer's instructions. Six specimens were then demineralized in 10 % HCl for 24 hours and the other six specimens were not demineralized in order to observe the interfacial surfaces with Hitachi X-450 SEM at 25Kv. Also shear bond strength were obtained using an Instron Testing Machine with a crosshead speed of 1mm/min. The following results were obtained : 1. Although shear bond strength of Superbond D-Liner(17.35 MPa) and Scotch-bond Multi-Purpose group(17.29 MPa) were higher than the All-Bond 2(12.80 MPa) and Prisma Universial Bond 3 (13.43 MPa), there were no significant statistic differences in the shear bond strength between 4 groups.(P<0.05) As a result of etching to dentin in Prism a Universial BOND 3 experimentally, the resin tag was formed, but shear bond strength was decreased. 2. The resin tag into the opened dentinal tubule was formed in Superbond D-Liner, Scotchbond Multi-Purpose, All-Bond 2(etching) and Prisma Universial Bond 3(etching), but not in the All-Bone 2 and Prism a Universial Bond 3(non-etching). 3. Strong, durable bonds between dentin and dentinal bonding agents are essential, not only resin tag into the dentinal tubules, but also hybrid layer.

• Journal of the Korean Vacuum Society
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• v.9 no.4
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• pp.341-345
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• 2000

We investigated the microstructures and the electrical properties of $ZrO_2$thin films deposited by reactive DC magnetron sputtering on (100) Si with different deposition conditions and annealing treatments. The refractive index of the $ZrO_2$ thin films increased with annealing temperatures and deposition powers, and approached to the ideal value of 2.0~2.2. The $ZrO_2$thin films deposited at the room temperature are amorphous, and the films are polycrystalline at the deposition temperature of $300^{\circ}C$. Both the thickness of the interfacial oxide layer and the root-mean-square (RMS) value of surface roughness increased upon annealing in the oxygen ambient. The Cmax value and leakage current value decreased with the increase of thickness of the interfacial oxide thickness.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.89-89
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• 2010

The atomic structure of Sb/Si(5 5 12)-$2{\times}1$ surface, deposited at room temperature (RT) and post-annealed, has been identified by scanning tunneling microscopy and the corresponding interface has been studied by synchrotron core-level photoemission spectroscopy. With 0.3-nm Sb deposition at RT and postannealing at $600^{\circ}C$, the surface has been facetted to (225)-$2{\times}1$ and (112)-$1{\times}1$, and its Si 2p has shown that all the Si 2p surface components have disappeared, while the single Sb-Si interfacial component has appeared. Such results indicate that all of surface Si atoms are replaced by Sb atoms and the charge is transferred from Si to passivating Sb-atoms at the top layer. With subsequent postannealing up to $700^{\circ}C$, the surface has been facetted to (113)-$2{\times}2$ and (335)-$4{\times}2$, still having Sb-Si interfacial component and partially re-exposed Si surface components. From the present study, the role of surfactant atom, Sb, as well as the thermal-stabilization of Sb-passivated high-index Si surface will be exposed. Especially, the key role of the Sb/Si(113)-$2{\times}2$, composed of Rebonded-Dimer-Rebonded atom 1D structures, for stabilization will be discussed.

• Journal of the Korean Society of Clothing and Textiles
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• v.17 no.3
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• pp.380-390
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• 1993

Effect of interfacial electrical conditions on adhesion of ${\alpha}-Fe_2O_3$ particles to PET fabric and the removal of ${\alpha}-Fe_2O_3$ particles from PET fabric, were investigated as functions of pH, electrolyte and ionic strength. The ${\zeta}$ potential of PET fiber and ${\alpha}-Fe_2O_3$ particles in the electrolyte solution were measured by streaming potential and microelectrophoresis methods respectively. The potential energy of interaction between ${\alpha}-Fe_2O_3$ particles and PET fabric were calculated by using the heterocoagulation theory for a sphere-plate model. The negative ${\zeta}$ potential of ${\alpha}-Fe_2O_3$ particle and PET fiber increased with pH, and then decreased certain pH and isoelectric points of ${\alpha}-Fe_2O_3$ particles and PET fiber were pH 6.5 and pH 3.5, respectively. The negative ${\zeta}$ potential of ${\alpha}-Fe_2O_3$ particle and PET fiber affected by electrolytes, were relatively high with polyanion electrolytes in solutions and were low with neutral salts. However, at surfactant solution, ${\zeta}$ potential was levelled off. The influence of the ionic strength on the ${\zeta}$ potential of ${\alpha}-Fe_2O_3$ particle was small but the negative ${\zeta}$ potential of PET fiber increased with the ionic strength. In the presence of anionic surfactant, the ${\zeta}$ potential of ${\alpha}-Fe_2O_3$ particle and PET fiber increased regardless of solution conditions. The interaction energy between ${\alpha}-Fe_2O_3$ particle and PET fabric increased with pH. The interaction energy was relatively high with polyanion electrolytes in solution, and the influence of ionic strength on the interaction energy was small, and the effective thickness of electrical double layer increased with decreasing the ionic strength.

• Membrane Journal
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• v.20 no.3
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• pp.235-240
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• 2010

The aim of this paper is to evaluate and compare the performances of forward osmosis (FO) membranes using different materials. The FO membranes were synthesized using interfacial polymerization method on hydrophobic polysulfone (PSf) and relatively hydrophilic polyethersulfone (PES) supports. The FO performance such as flux and back diffusion was measured. The resulting fluxes of PSf and PES FO membranes were $4.3\;L/m^2hr$ and $17.8\;L/m^2hr$, respectively. The flux of the PES FO membrane was higher than that of the PSf FO membrane. The results indicated that hydrophillictity of the support membrane is important for increasing flux in FO process. Moreover, with decreasing the support layer thickness, flux increased considerably.

• Analytical Science and Technology
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• v.6 no.2
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• pp.197-205
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• 1993

Blends of elemental Ni and 20 weight % Cr powder were milled for different period in a laboratory attritor. Powder size distribution, microstructure and X-ray diffraction characteristics were investigated as a function of processing period. Saturated magnetization, Ms and coercive force, Hc we also measured and compared with plasma melted ingot to confirm the mechanically alloyed states. Mechanical alloying occurred as a consequence of the partition of powders and the increase of interfacial area driving diffusing of Cr into Ni. However, magnetic properties of chemically homogeneous solid solution like melted ingot has not been observed even though steady state of submicron grain size has been achieved after milling over 15 hrs. Further mechanical alloying period gave refinement of grain size, which resulted in the increase of alloyed layer. It is concluded that homogenization should be controlled by the increase of interfacial area between constitutive powders caused by plastic particle deformation and by the diffusion of Cr within the alloyed phase into Ni-rich phase through lattice defects.

• Restorative Dentistry and Endodontics
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• v.28 no.3
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• pp.222-231
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• 2003

The purpose of this study was to compare shear bond strength and interfacial pattern of composite bond-ed to dentin using self-etching adhesive systems. Sixty extracted human molars with exposed occlusal dentin were divided into four groups and bonded with four adhesives and composites. Single Bond/Filtek Z 350(SB), Tyrian SPE-One-Step Plus/Aelitefil(TY), Prompt L-Pop/Filtek Z 250(LP), and One-Up Bond F/palfique Toughwell(OU). The results of this study were as follows; 1 Shear bond strength for OU was significantly lower than that of other groups(p＜0.05). No significant difference was founded among SB, TY, and LP. 2. Failure modes to dentin showed adhesive and mixed for SB TY and LP, but them for OU showed adhesive in all spceimens. 3. Dentin-resin interface showed close adaptation for SB, TY, and LP, but it showed gap for OU. 4. The hybrid layers for TY, LP OU were thinner than that of SB. Adhesive layers were observed between composite and hybrid layer, which were 5 $\mu\textrm{m}$ thick for TY and 10 $\mu\textrm{m}$ thick for OU.

• Journal of the Korean Magnetics Society
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• v.11 no.5
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• pp.226-231
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• 2001

The effect of interface reaction between Mn-Zn ferrite single crystal and 61 SiO$_2$-23Pbo-6ZnO-8Na$_2$O-2K$_2$O (mol%) glass on the magnetic properties of the ferrite was investigated. After the reaction, the hump of Zn concentration appeared at the ferrite adjacent to the interface. The initial permeability of the ferrite bonded with the glass at 700 $^{\circ}C$ was 1766 at 100 KHz and reduced to 907 after reaction at 1000$^{\circ}C$. The permeability degradation with increasing reaction temperature was considered to be attributed not only to the sixe diminution of the ferrite due to the its dissolution into the glass but also to the residual stress due to the difference in expansion coefficient between the ferrite and the diffusion layer-the region of the hump of Zn concentration-adjacent to the interface.

• Journal of the Korean Society for Marine Environment & Energy
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• v.2 no.2
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• pp.70-77
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• 1999

The disturbance of oil-water interface confined between tandem fences caused by a sequence of traveling vortices below the interface is investigated. The traveling vortices are assumed to be those detached from the tip of the fore fence. The potential flow is assumed and the density interface is replaced as a sheet of vortex. The shape of the interface is predicted by tracing a finite number of marker particles placed at the interface. The velocity of the marker particles is determined by the Biot-Savart integral along the vortex sheet plus the contribution from the traveling point vortices. The rate of change of vortex-sheet strength is predicted by using an evolution equation for vorticity. The calculated results obtained for various conditions demonstrate that the large amplitude of interfacial wave following the moving vortek can be generated by the vortices.