• The Korean Journal of Ceramics
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• v.5 no.2
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• pp.178-182
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• 1999

Simple binary $Na_2S-SiO_2$ oxysulfide glasses were prepared by a conventional melt-quench method in order to investigate the role of sulfur in glass structure and the electronic state. By X-ray photoelectron spectroscopy(XPS) measurement, S2p binding energy of the glass was observed at approximately 161eV which was close to that of ionic $S^{2-}$. The coordinating state around silicon atoms were investigated by ${29}^Si$ MAS-NMR measurement. The chemical shift observed from NMR supported that sulfur atom was joined to a silicon atom by substituting for an oxygen atom and was present as a non-bridging sulfide ion in low alkali content. On the other hand, it could be presumed that a portion of sulfur anions existed in an isolated state from the glass-network frame at high alkali content. The state of these sulfurs was also studied by Raman spectroscopy in detail.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.5
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• pp.1029-1034
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• 2012

This paper presents a cost-effective and high-performance film bulk acoustic resonator (FBAR) duplexer module for US-PCS handset applications. The FBAR device uses a glass wafer level packaging process, which is a more cost-effective alternative to the typical silicon capping process. The maximum insertion losses of the FBAR duplexer at the Tx and Rx bands are of 1.9 and 2.4 dB, respectively. The total thickness of the duplexer module is 1.2 mm, including the glass-wafer bonded Tx/Rx FBAR devices, PCB board, and transfer molding material.

• Restorative Dentistry and Endodontics
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• v.45 no.3
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• pp.36.1-36.10
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• 2020

Objectives: This study aims to assess the effect of universal adhesives pretreatment on the bond strength of resin-modified glass ionomer cement to dentin. Materials and Methods: Fifty caries-free human third molars were employed. The teeth were randomly assigned into five groups (n = 10) based on dentin surface pretreatments: Single Bond Universal (3M Oral Care), Gluma Bond Universal (Heraeus Kulzer), Prime&Bond Elect (Dentsply), Cavity Conditioner (GC) and control (no surface treatment). After Fuji II LC (GC) was bonded to the dentin surfaces, the specimens were stored for 7 days at 37℃. The specimens were segmented into microspecimens, and the microspecimens were subjugated to microtensile bond strength testing (1.0 mm/min). The modes of failure analyzed using a stereomicroscope and scanning electron microscopy. Data were statistically analyzed with one-way analysis of variance and Duncan tests (p = 0.05). Results: The surface pretreatments with the universal adhesives and conditioner increased the bond strength of Fuji II LC to dentin (p < 0.05). Single Bond Universal and Gluma Bond Universal provided higher bond strength to Fuji II LC than Cavity Conditioner (p < 0.05). The bond strengths obtained from Prime&Bond Elect and Cavity Conditioner were not statistically different (p > 0.05). Conclusions: The universal adhesives and polyacrylic acid conditioner could increase the bond strength of resin-modified glass ionomer cement (RMGIC) to dentin. The use of universal adhesives before the application of RMGIC may be more beneficial in improving bond strength.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.581-583
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• 1993

One of the principal problems encountered in the use of fiber reinforced composites is to establish an active fiber surface to achieve maximum adhesion between resin and fiber surface. In order to improve the interface bonding, the surface of glass fiber should be treated with silane coupling agent in ordinary composite manufacturing processes. However, the price of the coupling agent is very high and in the treating process voids are formed, which decreasees electrical and mechanical strength. We want to develope new process that will overcome the disadvantage of the coupling agent and achieve maximum adhesion at the interface between resin and fiber by active plasma treatment on the glass fiber surface. In this study, we investigate the improvement of contact angle on the glass plate surface as the first step in developing new GFRP.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.1
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• pp.51-58
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• 1999

The effects of glass composition on the wettability and reactivity with $ZrO_2$substrate was evaluated and fabrication variables and glass compositions was investigated. Various glass compositions was investigated. Alkaline earth silicate glass show good wettability and lower viscosity and crystallization of glass could be prevented by $B_2O_3$.The sealant glass begin to wet on $ZrO_2$substrate below $900^{\circ}C$ and porosity occurred in various glass compositions, the crystallization and porosity in the glass could be prevented by the addition of flux into glass composition. But flowability and reactivity of glass with $ZrO_2$substrate was enhanced. Processing variables should be optimized to reduce the porosity by enhancing the sintering of glass powder. Many silicate glasses were investigated for the applications of high temperature sealants. Wetting and bonding of glass was good enough to seal together between $ZrO_2$and other ceramic components of SOFC. But porosity and reaction layer were occurred in the sealant glass. It will be possible to produce glass sealant without porosity and reaction layer at the interface by optimization of processing variable and modify the glass compositions. In present study, wettability of glass-filler composite was investigated. The porosity, shape of filler and interfacial reactions of sealant glass with fillers were examined.

• Journal of Ocean Engineering and Technology
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• v.30 no.6
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• pp.520-525
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• 2016

In this study, a mixture of polypropylene fibers and glass fibers were used to weave polypropylene/glass fiber-reinforced composite panels with characteristics such as highly elongated short fibers, high ductility, anti-fouling, and hydrophobicity as a result of a directional property. Mechanical and environmental tests were carried out with specimens fabricated with this composite panel, and its applicability to shipbuilding and ocean leisure industries was evaluated through a comparison with existing glass fiber-reinforced composite materials. The results of this experiment verified the excellence of the polypropylene/glass-mixed woven fiber-reinforced composite material compared to the existing glass fiber-reinforced composite material. However, the forming process needs to be changed to improve the weak interfacial bonding, and the properties of the composite material itself could be improved through mixed weaving with other fibers after development. Maximizing of the advantages of the polypropylene fibers and overcoming their shortcomings will improve their applicability to the shipbuilding, ocean leisure, and other industries, and increase the value of polypropylene fibers in the composite material market.

• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.9-20
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• 2005

This study was carried out to select most efficient bonding methods of geogrid at the interface of old concrete pavement before placing asphalt overlay layer for reflection cracking retardation. Three bonding methods, a RSC-4 emulsified asphalt, a compound and an unsaturated polyester resin (UPR) were compared in this study. Three types of asphalt mixture (AC 60-80, RLDPE 8%, PG 76-22) and a dense-graded aggregate were used for overlay asphalt pavement. A reinforcing material which consists of a woven fabric underneath a glass fiber grid was used. An expedite test method which is for simulating mixed mode (mode I and II) fracture test was performed using a wheel tracker in laboratory. Cracking development by load repetition was measured as fatigue life (number of load cycle) and expansion of specimen body were measured for each test specimen. The results showed that UPR was the best and RSC-4 the next. But considering field applicability, RSC-4 was considered as an appropriate choice for bonding reinforcing material.

• Restorative Dentistry and Endodontics
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• v.28 no.3
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• pp.203-208
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• 2003

The purpose of this study was to evaluate the effect of salivary contamination of teeth on bonding efficacy of self-priming and self-etching DBSs. The materials used were Single Bond(SB, self-priming system, 3M), Unifil Bond(UB, self-etching system, GC), and Scotchbond Multi-Purpose Plus(SM, 3M) as control. Forty five human molars randomly allocated to three groups as dentin bonding systems tested and embedded in epoxy resin. Then the specimens were wet-ground to expose flat buccal enamel surface or flat occlusal dentin surface and cut bucco-lingually to form two halves with slow speed diamond saw. One of them was used under non-contamination, other under contamination with saliva. The bonding procedure was according to the manufacturer's directions and resin composite(Z-100, 3M Dental Products, St. Paul, MN) was built-up on the bonded surface 5mm high. The specimens were ground carefully at the enamel-composite interface with fine finishing round diamond bur to create an hour-glass shape yielding bonded surface areas of $1.5{\pm}0.1\textrm{mm}^2$. The specimens were bonded to the modified microtensile testing apparatus with cyanoacrylate, attached to the universal testing machine and stressed in tension at a CHS of 1mm/min. The tensile force at failure was recorded and converted to a tensile stress(MPa). Mean values and standard deviations of the bond strength are listed in table. One-way ANOVA was used to determine significant difference at the 95% level. The bond strength of SBMP and SB were not affected by salivary contamination, but that of UB was significantly affected by salivary contamination. These results indicate that DBSs with total etch technique seems less likely affected by salivary contamination in bonding procedure.

• Macromolecular Research
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• v.15 no.7
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• pp.688-692
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• 2007

The hydrogen-bonding induced alternating multilayer thin films of dendrimers and block copolymer micelles were demonstrated. The block copolymer micelles derived from amphiphilic poly(2-ethyl-2-oxazoline)block-$poly({\varepsilon}-carprolactone)$ (PEtOz-PCL) in aqueous phase have a core-shell structure with a mean hydrodynamic diameter of 26 nm. The hydrogen bonding between the PEtOz outer shell of micelle and the carboxyl unit of poly(amidoamine) dendrimer of generation 4.5 (PAMAM-4.5G) at pH 3 was utilized as a driving force for the layerby-layer alternating deposition. The multilayer thin film was fabricated on the poly(methyl methacrylate) (PMMA) thin film spin-coated on silicon wafer or glass substrate by the alternate dipping of PEtOz-PCL micelles and PAMAM dendrimers in aqueous solution at pH 3. The formation of multilayer thin film was characterized by using ellipsometry, UV-vis spectroscopy, and atomic force microscopy. The PEtOz outer shell of PEtOz-PCL micelle provided the pH-responsive hydrogen bonding sites with peripheral carboxylic acids of PAM AM dendrimer. The multilayer thin film was reversibly removed after dipping in aqueous solution at $pH{\geq}5.6$ due to dissociation of the hydrogen bonding between PEtOz shell of PEtOz-PCL micelle and peripheral carboxyl units of PAMAM dendrimer.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.5
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• pp.367-372
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• 2020

As packaging processes for atomic gyroscope vapor cells, the glass tube tip-off process, anodic bonding, and paste sealing have been widely studied. However, there are stability issues in the alkali metal which are caused by impurity elements and leakage during high-temperature processes. In this study, we investigated the applicability of a vapor cell low-temperature packaging process by depositing Au on a Pyrex cell in addition to forming an Au-Sn thin film on a cap to cover the cell, followed by laser irradiation of the Au/Au-Sn interface. The mechanism of the thin film bonding was evaluated by XRD, while the packaging reliability of an Ne gas-filled vapor cell was characterized by variation of plasma discharge behavior with time. Furthermore, we confirmed that the Rb alkaline metal inside the vapor cell showed no color change, indicating no oxidation occurred during the process.