• Restorative Dentistry and Endodontics
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• 제46권1호
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• pp.3.1-3.14
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• 2021

Objectives: This study aimed to evaluate the interface between a calcium silicate cement (CSC), Biodentine and dental adhesives in terms of sealing ability. Materials and Methods: Microleakage test: 160 standardized class II cavities were prepared on 80 extracted human molars. The cavities were filled with Biodentine and then divided into 2 experimental groups according to the time of restoration: composite resin obturation 15 minutes after Biodentine handling (D0); restoration after 7 days (D7). Each group was then divided into 8 subgroups (n = 5) according to the adhesive system used: etch-and-rinse adhesive (Prime & Bond); self-etch adhesive 2 steps (Optibond XTR and Clearfil SE Bond); self-etch adhesive 1 step (Xeno III, G-aenial Bond, and Clearfil Tri-S Bond); and universal used as etch-and-rinse or self-etch (ScotchBond Universal ER or SE). After thermocycling, the teeth were immersed in a silver nitrate solution, stained, longitudinally sectioned, and the Biodentine/adhesive percolation was quantified. Scanning electron microscopic observations: Biodentine/adhesive interfaces were observed. Results: A tendency towards less microleakage was observed when Biodentine was etched (2.47%) and when restorations were done without delay (D0: 4.31%, D7: 6.78%), but this was not significant. The adhesives containing 10-methacryloyloxydecyl dihydrogen phosphate monomer showed the most stable results at both times studied. All Biodentine/adhesive interfaces were homogeneous and regular. Conclusions: The good sealing of the CSC/adhesive interface is not a function of the system adhesive family used or the cement maturation before restoration. Biodentine can be used as a dentine substitute.

• Journal of Pharmaceutical Investigation
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• 제38권4호
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• pp.223-228
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• 2008

The purpose of this study was to investigate the feasibility of developing transdermal drug delivery system (TDDS) for fentanyl used for the management of chronic cancer pain. The effect of type of pressure sensitive adhesive on the permeation of fentanyl from polyisobutylene (PIB), silicone and acrylic adhesive was evaluated. Due to the good adhesive force and relatively steady flux for 3 days, both acrylic and PIB adhesives were chosen for further study. The permeation rate of fentanyl was the highest from acrylic adhesive with hydroxyl functional group. Permeation rate increased linearly as the concentration of fentanyl in acrylic adhesive was increased from 2.5% to 10%. In case of PIB adhesive, crystals of fentanyl were developed above 5% drug load. $Crovol^{(R)}$ A40, $Crovol^{(R)}$ PK40 and Plurol $oleique^{(R)}$ provided higher flux of fentanyl.

• Advances in materials Research
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• 제5권1호
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• pp.11-20
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• 2016

In bonded composite repair of aircraft structures, the damage of the adhesive can thus reduce significantly the efficiency and the durability of the bonded composite repair. The adhesive damage models using critical zone have proven their effectiveness due to simplicity and ap-plicability of the damage criteria in these models. The scope of this study is to analyze the effects of the patch thickness and the adhesive thickness on the damage damage in bonded composite repair of aircraft structures by using modified damage zone theory. The obtained results show that, when the thickness of adhesive increases the damage zone increases and the adhesive loses its rigidity, inversely when the patch is reduced the adhesive damage be-comes more significant.

• International Journal of Aerospace System Engineering
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• 제1권1호
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• pp.44-47
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• 2014

This study proposes a development for the nano silver adhesive, which is applicable to high efficiency LED(light-emitting diode) light. The important issue of LED light is heat exhaust from LED. Generally, the middle area of LED light is increased up to 380K. Therefore, the bottleneck between LED chip and heat sink are caused by high temperature. In this work, the adhesive material between LED Chip and heat sink was newly developed for improvement of bottleneck. The nano silver was adopted to solve heat problem of chip on board package for LED light. In order to evaluate the performance of the nano silver adhesive, the thermal analysis was performed. Moreover both adhesive performance and heat exhaust were verified through the prototype test. From the experimental test results, it is found that the developed nano silver adhesive has the high performance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.877-878
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• 2006

In electric motor coaches, the rolling stocks move by the adhesive effort between rail and driving wheel. Generally, the adhesive effort is defined by the function of both the weight of electric motor coach and the adhesive effort between rails and driving wheel. The characteristics of adhesive effort is strongly affected by the conditions between rails and driving wheel. When the adhesive effort decreases suddenly, inertia conversion the electric motor coach has slip phenomena. This paper proposes a anti-slip control algorithm which uses the maximum adhesive effort by instantaneous estimation of adhesion force using load torque disturbance observer. Based on this estimated adhesive effort, the anti-slip control is performed to obtain the maximum transfer of the tractive effort.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.421-425
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• 2007

In the fabrication of dry adhesive structure, increasing contact-points or contact-area is the primary goal because the adhesive force grows in proportion to the contact-area. The simplest way to extend the contact surface is the fabrication by using soft materials. However, the column-array structure could confront the matting phenomenon which columns are stuck together. Therefore, we need a novel design to reduce the effective stiffness with adequate stiff materials like a gecko's setae. In this study, we propose a novel design for the dry adhesive structure. Moreover, we analyzed whether the adhesive structure conforms the rough surface sufficiently through finite element method adopted the non-bonding interaction as the body force. Also, we fabricated the novel structures via UV lithography and some techniques. In addition, we examined the adhesive force of the novel structures.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 추계학술발표대회 논문집
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• pp.57-60
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• 2005

Composite-to-aluminum joins were tested to get failure loads and modes for three types of joins; adhesive bonding, bolt fastening, and adhesive-bolt hybrid joining. Film type adhesive FM73 and paste type adhesive Cytec EA9394S were used for aluminum and composite bonding to make a double-lap joint. A digital microscope camcorder was used to monitor the failure initiation and propagation. It was found that the hybrid joining is an effective method to strengthen the joint when the mechanical fastening is stronger than the bonding as in the case of using the paste type adhesive. On the contrary, when the strength of the bolted joint is lower than the strength of the bonded joint as in the joint with the film type adhesive, the bolt joining contribute little to the hybrid joint strength.

• 한국철도학회논문집
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• 제8권3호
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• pp.216-221
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• 2005

In electric motor coaches, the rolling stocks move by the adhesive effort between rail and driving wheel. Generally, the adhesive effort is defined by the function of both the wright of electric motor coach and the adhesive effort between rails and driving wheel. The characteristics of adhesive effort is strongly affected by the conditions between rails and driving wheel. When the adhesive effort decreases suddenly, the electric motor coach has slip phenomena. This paper proposes a re-adhesion control based on disturbance observer and sensor-less vector control. The numerical simulation and experimental results point out that the proposed re-adhesion control system has the desired driving wheel torque response for the tested bogie system of electric coach. Based on this estimated adhesive effort, the re-adhesion control is performed to obtain the maximum transfer of the tractive effort.

• 한국공작기계학회논문집
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• 제17권3호
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• pp.14-19
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• 2008

In the semiconductor IC(Integrated Circuit) package, the top surface of silicon chip is directly attached to the area of the leadframe with a double-sided adhesive layer, in which the base layer have the upper adhesive layer and the lower adhesive layer. The IC package structure has been known to encounter a thermo-mechanical failure mode such as delamination. This failure mode is due to the residual stress on the adhesive surface of silicon chip and leadframe in the curing-cooling process. The induced thermal stress in the curing process has an influence on the cooling residual stress on the silicon chip and leadframe. In this paper, for the minimization of the chip surface damage, the adhesive topologies on the silicon chip are studied through the finite element analysis(FEA).

• Computers and Concrete
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• 제15권3호
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• pp.337-355
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• 2015

In this scientific work, an improved analytical solution for adhesive stresses in a concrete beam bonded with the FRP plate is developed by including the effect of the adherend shear deformations. The analysis is based on the deformation compatibility approach where both the shear and normal stresses are assumed to be invariant across the adhesive layer thickness. The shear stress distribution is supposed to be parabolic across the depth of the adherends in computing the adhesive shear stress and Timoshenko's beam theory is employed in predicting adhesive normal stress to consider the shear deformation. Numerical results from the present analysis are presented both to demonstrate the advantages of the present solution over existing ones and to illustrate the main characteristics of adhesive stress distributions.