• Title/Summary/Keyword: school bonding

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AN EXPERIMENTAL STUDY ON THE BOND STRENGTH OF THE LIGHT ACTIVATED COMPOSITE RESIN BONDED TO THE ETCHED PORCELAIN (부식된 도재와 광중합성 수지와의 접합강도에 관한 실험적연구)

  • Lee, June-Kyu;Kay, Kee-Sung
    • The Journal of Korean Academy of Prosthodontics
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    • v.25 no.1
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    • pp.363-378
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    • 1987
  • 도재소부전장관에서 금속이 노출되지 않고 도재만이 파절시, 구강내에서 직접 행할 수 있는 심미적 수복 방법으로서 복합성 수지를 이용한 수복 방법이 널리 이용되고 있는데 본실험의 목적은 도재와 광중합성 수지간의 접합강도를 비교 측정코저 함에 있다. 본 실험에서는 주사전자 현미경을 사용하여 도재의 부식액 (5% 불화수소산용액, Excelco's porcelain etching gel) 및 부식 시간(2.5분, 5분, 10분, 20분)에 따른 부식양상을 먼저 관찰하였다. 그다음 각기 다른 시간에서 부식 처리된 도재와 대조군으로서 미부식 처리된 도재에 광중합성 수지를 부착시킬시, 첫째 Silane coupling agent(Scotch-Prime)도포후 광중합성 수지를 결합 시켰고 둘째 bonding agent(Scotch bond)도포후 광중합성 수지를 결합시켰으며 셋째 Silane coupling agent(Scotch-Prime)에 bonding agent(Scotch bond)를 도포후 광중합성 수지로 결합 시킨후, 인장강도 측정기 (Shimadzu universal testing machine)를 사용하여 결합력을 측정한 결과 다음과 같은 결론을 얻었다. 1. 부식처리된 도재가 미부식 처리된 도재 보다 결합력이 높았다. (p<0.05, P<0.001) 2. 부식 처리된 도재나 미부식 처리된 도재에 있어서 silane coupling agent 도포후 bonding agent로 처치한 경우 가장 결합력이 높았으며 그다음 silane coupling agent로 처치한 경우, bonding agent로 처치한 경우의 순이었다. 3. 도재부식 시간의 증가에 따른 결합력의 차이는 5% HF용액으로 부식 처리된 도재와 Excelco로 부식 처리된 도재에 있어서 5분 정도 까지는 결합력의 증가를 보였으나 그 후에는 결합력에 있어서 거의 증가하지 않는 양상을 보였다. 4. Excelco로 부식 처리된 도재와 5% HF 용액으로 부식처리된 도재간의 결합력 차이에 있어서 bonding agent만으로 처치한 경우에는 두결합력 사이에 서로 유의한 차이를 보이지 않았으나 (P>0.5) silane coupling agent만으로 처치한 경우와 silane coupling agent 도포후 bonding agent로 처치한 경우에는 두결합력 사이에 서로 유의한 차이를 보였다. (P<0.05, P<0.001) 5. Excelco로 부식처리된 도재가 5% HF 용액으로 부식처리된 도재보다 부식정도가 더 현저하였다.

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Analysis of the bonding strength according to surface treatments of dental Co-Cr alloy for porcelain fused to metal (치과용 Co-Cr 금속도재관의 표면처리에 의한 도재와의 결합 강도 분석)

  • Park, Hee-Geun;Park, Won-UK;Zhao, Jinming;Hwang, Kyu-Hong
    • Journal of Technologic Dentistry
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    • v.38 no.3
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    • pp.175-183
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    • 2016
  • Purpose: Observation of Oxide Film Formation and Bonding Strength according to surface treatment of Co-Cr Alloy for porcelain fused to Metal. Methods: metal specimens $0.5mm{\times}25mm{\times}4mm$ in size were made using Co-Cr alloys for porcelain fused to metal crown (Heraenium P, Tae jung Medis). Dental porcelain $0.5mm{\times}25mm{\times}4mm$ in size was sintered on the metal specimens after changing the etching time, sandblasting condition, and heat treatment temperature. Subsequently, the bonding strength was compared by the three-point flexural strength test using a universal testing machine (UTM) to observe the fracture surface and oxidized layers. Results: With regard to the experimental group treated with acid-etching, Specimen 1 treated for 25 minutes (B-3) showed the highest bonding strength, and Specimen 2 treated only with sandblasting showed the most excellent bonding force at 3.5 bar (C-3). With regard to the experimental group treated with sandblasting at 3.5 bar after acid-etching for 25 minutes, Specimen 3 with heat treatment at $980^{\circ}C$ (D-3) showed the highest bonding strength. Conclusion: The specimen which went through both sandblasting and etching, showed an excellent ceramicmetal bond strength.

COMPARATIVE TENSILE BOND STRENGTH OF HEAT-CURED, COLD-CURED, AND LIGHT CURED DENTURE BASE RESINS BONDED TO CONTINUOUS-PRESSURE INJECTION TYPE DENTURE BASE RESIN (지속적 가압 주사식 열중합 의치상 레진에 대한 열중합, 자가중합 및 광중합 레진의 결합력에 관한 비교분석)

  • Whang Seung-Woo;Chung Moon-Kyu
    • The Journal of Korean Academy of Prosthodontics
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    • v.31 no.3
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    • pp.385-393
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    • 1993
  • Injection processing of denture base resin was introduced by Pryer in 1942, in an attempt to reduce processing shrinkage. More recently a continuous-pressure injection type technique has been developed (SR-Ivocap, Ivoclar AG, Schaan, Liechtenstein.), and it reduced processing error and increased resin density. The purpose of this study was to compare tensile bond strength of heat-cured, cold-cured, and light-cured denture base resin bonded to continuous-pressure injection type resin. To know it, 60 cylindrical resin specimens were fabricated, and tensile bond strength were measured. The results were as follows : 1. The mean tensile bond strength bonded to continuous-pressure injection type resin was lower than bonded to conventional heat cured resin. But tensile bond strength of conventional heat cured resin bonding with light cured resin was lower than continuous-pressure injection type resin. 2. Of the tensile bond strength bonded to continuous-pressure injection type resin, tensile bond strength bonding with continuous-pressure injection type resin was the greatest(but not significantly different from bonding with conventional heat cured resin), followed by cold-cured, light-cured resin. 3. Of the tensile bond strength bonded to conventional heat cured resin, tensile bond strength bonding with conventional heat cured resin was the greatest and followed by continuous-pressure injection type resin, cold-cured resin, light-cured resin. According to these results, bonding of continuous-pressure injection type resin with conventional heat cured resin or continuous-pressure injection type resin is acceptable, but bonding with light-cured resin is questionable.

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EFFECT OF AN INTERMEDIATE BONDING RESIN AND FLOWABLE RESIN ON THE COMPATIBILITY OF TWO-STEP TOTAL ETCHING ADHESIVES WITH A SELF-CURING COMPOSITE RESIN (자가 중합 복합 레진과 두 단계 산 부식 접착제의 친화성에 대한 중간 접착제와 흐름성 레진의 효과)

  • Choi, Sook-Kyung;Yum, Ji-Wan;Kim, Hyeon-Cheol;Hur, Bock;Park, Jeong-Kil
    • Restorative Dentistry and Endodontics
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    • v.34 no.5
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    • pp.397-405
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    • 2009
  • This study compared the effect of an activator, intermediate bonding resin and low-viscosity flowable resin on the microtensile bond strength of a self-curing composite resin used with two-step total etching adhesives. Twenty extracted permanent molars were used. The teeth were assigned randomly to nine groups (n=10) according to the adhesive system and application of additional methods (activator, intermediate adhesive, flowable resin). The bonding agents and additional applications of each group were applied to the dentin surfaces. Self-curing composite resin buildups were made for each tooth to form a core, 5mm in height. The restored teeth were then stored in distilled water at room temperature for 24h before sectioning. The microtensile bond strength of all specimens was examined. The data was analyzed statistically by one-way ANOVA and a Scheffe's test. The application of an intermediate bonding resin (Optibond FL adhesive) and low-viscosity flowable resin (Tetric N-flow) produced higher bond strength than that with the activator in all groups. Regardless of the method selected, Optibond solo plus produced the lowest ${\mu}TBS$ to dentin. The failure modes of the tested dentin bonding agents were mostly adhesive failure but there were some cases showed cohesive failure in the resin.

The Influence of Players' Self-Esteem, Game-Efficacy, and Social Capital on Life Satisfaction Focused on Hedonic and Eudaimonic Happiness (게임 이용자들의 자아 존중감, 게임 효능감, 사회 자본이 삶의 만족도에 미치는 영향에 관한 연구: 헤도닉과 유다이모닉 행복 관점을 중심으로)

  • Lee, Hye Rim;Jeong, Eui Jun
    • Journal of Korea Multimedia Society
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    • v.18 no.9
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    • pp.1118-1130
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    • 2015
  • The current study explores a possible mechanism through which game users' integrated sociopsychological factors lead to a higher level of life satisfaction, based on desire-fulfillment theory as well as hedonic and eudaimonic approaches to happiness. Using data from a survey of 789 game users in South Korea, we tested the relationships of psychological variables (self-esteem and game and life-efficacy), social variables (bonding and bridging social capital), and demographic variables (age and gender) with life satisfaction. Results show that self-esteem and game efficacy were an important antecedent to the degree of users' life satisfaction. Both bonding and bridging social capital increased life satisfaction. The importance of perspectives as well as their implications for game users and further associated research is explored.

Development of New Cancer Therapy and Its Physics

  • Oh, Hung-Kuk;Jeong, Jin-Ha
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2001.05a
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    • pp.147-155
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    • 2001
  • Nasucon lamp and Russian ones, which are coated with some special materials on the glass bulb, gave good clinical results for a cancer therapy. They are experimentally studied with Automatic Bioelectric Response Recorder on the six placements of the electrodes (two feet, two hands and two foreheads). They reduced the current rather than the control (natural) state. However infrared lamp and Chinese God light did not reduced the value current. Hemoglobin in blood. Brown gas, Ti$_3$SiC$_2$ and Nasucon have planar crystallizing $\pi$-bonding bonding layer and covalent bonding one in sequence commonly and thus the alternating magnetic fields are protected. Nasucon lamp and Russian ones utilized electric bulbs in order to generate alternating magnetic fields and to produce absorbing force.

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Vibration Analysis and Design of Ultrasonic Horn to the Bonded Dissimilar Materials (이종접합을 위한 초음파 혼 설계 및 진동해석)

  • Jung, An-Mok;Jeon, Euy-Sik;Kim, Chul-Ho
    • Proceedings of the KWS Conference
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    • 2009.11a
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    • pp.79-79
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    • 2009
  • Ultrasonic fine welding, cutting, cleaning, inspection and measurement is widely used in various fields over 20kHz. However, for High Frequency of 60kHz or more study areas is still insufficient, and the result is lacking. Therefore, this study used ultrasonic horn to the Bonding of Dissimilar Materials for effective design. Finite element analysis (FEA) is using the equations of motion to establish the model. The optimal design for the basic interpretation of vibration characteristics of the ultrasonic measures horn will examine the design.

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Effects of Fiber Aspect Ratio, Fiber Content, and Bonding Agent on Tensile and Tear Properties of Short-Fiber Reinforced Rubber

  • Lee, Dong-Joo;Ryu, Sang-Ryeoul
    • Journal of Mechanical Science and Technology
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    • v.15 no.1
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    • pp.35-43
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    • 2001
  • Both tensile and tear properties of short-fiber reinforced Chloroprene rubber have been studied as functions of the fiber aspect ratio and fiber content. Both properties increased when both the fiber aspect ratio and fiber content were increased. The fiber reinforced rubbers exhibited maximum values of these properties at a fiber aspect ratio of about 300. When the fiber aspect ratio exceeds 400, the mechanical properties decreased with the fiber content because of the non-uniform dispersion of fibers. The tensile modulus was compared with the prediction by the Halpin-Tsai equations for randomly oriented cases. A bonding agent was used in the fiber treating process. It was found that the ultimate tensile strength, torque, tearing energy and tensile modulus of the rubbers with treated fibers were much higher than those with untreated ones.

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Wafer-Level Package of RF MEMS Switch using Au/Sn Eutectic Bonding and Glass Dry Etch (금/주석 공융점 접합과 유리 기판의 건식 식각을 이용한 고주파 MEMS 스위치의 기판 단위 실장)

  • Kang, Sung-Chan;Jang, Yeon-Su;Kim, Hyeon-Cheol;Chun, Kuk-Jin
    • Journal of Sensor Science and Technology
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    • v.20 no.1
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    • pp.58-63
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    • 2011
  • A low loss radio frequency(RF) micro electro mechanical systems(MEMS) switch driven by a low actuation voltage was designed for the development of a new RF MEMS switch. The RF MEMS switch should be encapsulated. The glass cap and fabricated RF MEMS switch were assembled by the Au/Sn eutectic bonding principle for wafer-level packaging. The through-vias on the glass substrate was made by the glass dry etching and Au electroplating process. The packaged RF MEMS switch had an actuation voltage of 12.5 V, an insertion loss below 0.25 dB, a return loss above 16.6 dB, and an isolation value above 41.4 dB at 6 GHz.

Self-Alignment and Bonding of Microparts Using Adhesive Droplets

  • Sato, Kaiji;Lee, Keun-Uk;Nishimura, Masahiko;Okutsu, Kazutoshi
    • International Journal of Precision Engineering and Manufacturing
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    • v.8 no.2
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    • pp.75-79
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    • 2007
  • This paper describes the self-alignment and bonding of microparts using adhesive surface tension to assemble microsystems in air. The alignment and bonding were tested experimentally using adhesive droplets, and the resulting performance was evaluated. The adhesive, which was inorganic and water-soluble before hardening, was diluted with water to a ratio of 10:1 so that its surface tension generated a sufficient restoring force for self-alignment. The experimental results showed that the average of the alignment errors obtained using the adhesive on $1.0\times1.0\times0.15-mm$ microparts was less than $2{\mu}m$ in the X and Y directions and 0.2 degrees in the e direction. These alignment errors were almost the same as those obtained using water. The use of a suitable adhesive had no negative effects on the alignment accuracy. The average tensile strength of the adhesive bond after self-alignment was $0.61N/mm^2$.