• 한국항공우주학회지
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• 제37권8호
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• pp.751-758
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• 2009

본 논문에서는 항공기 구조용 탄소 복합재 단일겹침 접착 체결부에서, 파손하중에 영향을 미치는 주요인자들의 효과를 실험으로 연구하였다. 실험을 위해 제작공정 4가지, 겹침 길이 5가지, 모재 두께 4가지에 대한 시편 총 335개를 제작하였다. 예상대로 겹침길이가 감소할수록, 모재두께가 증가할수록 파손강도가 높아지는 것을 확인하였다. 그러나 제작공정의 측면에서는, 접착제가 없는 일체성형 시편과 이차접착 시편의 강도가 동시접착이나 접착제를 사용한 일체성형 시편에서보다 높은 파손강도를 보이는 흥미로운 사실을 발견하였다. 특히 이차접착 시편의 강도가 일체성형 시편의 강도와 유사하거나 더 높은 현상을 발견하였는데, 이는 접착제의 강도가 모재의 층간강도보다 높거나 최소한 비슷한 수준임을 의미하는 것으로 볼 수 있다.

• 한방재활의학과학회지
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• 제24권1호
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• pp.77-82
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• 2014

Objectives Adhesive capsulitis (AC) is a restricted shoulder range of motion. Rotator cuff disease (RCD) has been believed to be a major etiologic factor of AC, however, how soon is the development time from RCD to AC (DTRA) has not been elucidated. The purpose of our study was to evaluate the correlation between the ultrasonographic characteristics of RCD and the DTRA. Methods Total 40 patients who were diagnosed as AC were recruited. The clinical characteristics of RCD were diagnosed by ultrasonography and classified with the Southern California Orthopedic Institute for Rotator Cuff Classification. The correlation was analyzed with Mann-Whitney U test and one-way analysis of variance. Results 60% of full thickness tear and 40% of partial thickness tear patients (10 male and 30 female, mean age of $54.0{\pm}8.4$ years) and 38% of bursitis and 21% of neovascularization were observed. The mean value of DTRA was $74.8{\pm}131.3$ days. There were no correlation between DTRA and gender (p=0.63), location of the partial tear (p=0.63), the severity of the partial thickness tear (p=0.63), full thickness tear (p=0.66) and completeness of the tear (p=0.16). The presence of bursitis or neovascularization was not associated with DTRA (p=0.60, p=0.61). Conclusions Although RCD is a major etiologic factor of AC, the severity, the type of RCD and the presence of bursitis and neovascularization were not statistically correlated with the DTRA in our study. Comprehensive consideration about etiologic factor analysis of AC will be needed with prospective study design for future study.

• Composites Research
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• 제28권6호
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• pp.356-360
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• 2015

본 논문에서는 복합재료 접합부의 파손거동 예측을 위해 CFRP를 DCB 형태로 가공하여 Mode 1 정적해석을 수행하였다. 시편은 각각 25 mm, 30 mm, 35 mm, 40 mm의 4가지 경우로, 방향성을 지니지 않은 탄소섬유의 물성치를 이용하였다. Model 1 해석을 통해 나온 결론으로는 25 mm에서 낮은 힘으로 가장 늦게 접착부에서 떨어지는 것을 볼 수 있었으며 40 mm에서 가장 높은 힘이 발생하였다. 접합부의 접착계면 탈락은 25 mm의 시험편 두께에서 9.75 mm로 가장 느리게 나타났으며 40 mm의 시험편 두께에서 7.82 mm로 가장 빠르게 나타난 것을 볼 수 있었다. 이 탈락은 시험편의 파괴에 의한 것이다. 접착계면의 탈락과 이에 따른 반력에 관한 본 연구 결과는 CFRP의 안전한 구조설계에 이바지할 수 있을 것으로 사료된다.

• 대한기계학회논문집
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• 제19권8호
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• pp.1869-1875
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• 1995

The adhesively bonded tubular single lap joint shows a nonlinear relationship between the applied torque and the resulting displacement under the static-torsional loading, which is induced from the nonlinear properties of the adhesive. However the torque transmission capability in the case of the dynamic-torsional loading is much less than that in the case of the static-torsional loading, the stress level of the adhesive is usually in the region of the linear stress and strain relation and the stress distributions of the joint can be obtained by the linear analysis. In this paper, a failure model for the adhesively bonded tubular single lap joint under the torsional fatigue loading was developed with respect to the adhesive thickness that was a critical factor in predicting the static torque transional-cyclic loadings was proposed.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2001년도 추계학술대회(제116회) 및 13회 Workshop 제3회 한ㆍ일 치과보존학회 공동학술대회 초록집
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• pp.559.2-559
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• 2001

Fanning et al.(1995) suggested that the incorporation of filler particles into a system's adhesive could increase the shear bond strength by improving the mechanical properties. In this study, shear bond strengths of experimental filled adhesives with varying filler levels were tested to determine the optimal filler level. The diametrile tensile strength and thickness of each experimental adhesive were also examined to evaluate if there is a relation between shear bond strength and mechanical properties of adhesive.(omitted)

• Journal of the Korean Wood Science and Technology
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• 제24권2호
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• pp.42-45
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• 1996

A residue from the newsprint waste was investigated as a filler in adhesive for bonding southern pine plywood. The residue was prepared by drying the wet residue to 8% moisture content and grinding the dry material using a laboratory Wiley mitt with a 75-${\mu}m$(200-mesh) screen. The residue was compared to a commercial filler commonly used in structural plywood adhesives. A total of 48 three-ply panels. 12.7mm nominal thickness and 0.3 by 0.3 m in size, were fabricated at two press times(4 and 5 min) and three assembly times(20, 40 and 60 min). Evaluations of the residue were carried out by performance tension shear tests after two 4-hour boil accelerated aging tests on plywood. The test results included tension shear strength and estimated wood failure values. All plywood made with the residue filler were comparable to the control-bonded plywood. These results indicate that residue from the newsprint waste streams would be suitable as filler for plywood adhesives.

• Journal of Pharmaceutical Investigation
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• 제25권4호
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• pp.339-345
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• 1995

For the effective treatment of aphthous stomatitis, the matrix type mucoadhesive patches containing triamcinolone acetonide have been formulated. The drug layer was obtained by drying the polymer gel which was prepared with carbomer 934P, ammoniomethacrylate copolymer, titanium dioxide and polyethylene glycol 400. The effects of the content of additives on physical characteristics of the polymer gel and the drug layer were evaluated. The addition of carbomer increased the yield point and the zero-shear viscosity of polymer gel as well as the thickness, the water absorption ratio, the adhesive time and $T_{50%}$ of drug layer. The adhesive time and the water absorption ratio of drug layer were also improved by the addition of ammoniomethacrylate copolymer, but the addition of titanium dioxide had decreased the zero-shear viscosity of polymer gel and the adhesive time of drug layer.

• Steel and Composite Structures
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• 제20권2호
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• pp.413-429
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• 2016

A theoretical method to predict the interfacial stresses in the adhesive layer of reinforced concrete beams strengthened with externally bonded carbon fiber-reinforced polymer (CFRP) plate is presented. The analysis provides efficient calculations for both shear and normal interfacial stresses in reinforced concrete beams strengthened with composite plates, and accounts for various effects of Poisson's ratio and Young's modulus of adhesive. Such interfacial stresses play a fundamental role in the mechanics of plated beams, because they can produce a sudden and premature failure. The analysis is based on equilibrium and deformations compatibility approach developed by Tounsi. In the present theoretical analysis, the adherend shear deformations are taken into account by assuming a parabolic shear stress through the thickness of both the reinforced concrete beam and bonded plate. The paper is concluded with a summary and recommendations for the design of the strengthened beam.

• Applied Microscopy
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• 제50권
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• pp.13.1-13.7
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• 2020

We examined the morphology of fertilized egg and ultrastructures of fertilized egg envelopes of Ancistrus cirrhosus belong to Loricariidae using light and electron microscopes. The fertilized eggs formed a mass on the spawning place and were yellowish, spherical, non-transparent, demersal, adhesive, and a narrow perivitelline space. But, the adhesiveness of fertilized eggs was disappeared after spawning excluding contact parts. The micropyle with funnel shape was surrounded by 15-19 furrow lines of egg envelope in a spoke-like pattern. The outer surface of egg envelope has smooth side and inner surface of egg envelope was rough with grooves. Also, the total thickness of the fertilized egg envelope was about 32.58 ± 0.85 ㎛ (n = 20), and the fertilized egg envelope consisted of three layers, an outer adhesive electron-dense layer, a middle layer with low electron density and an inner electron-dense layer with grooves in counter structure from other most teleost. Collectively, these morphological characteristics and adhesive property of fertilized egg, and ultrastructures of micropyle, outer surface, and section of fertilized egg envelope are showed species specificity.

• Journal of the Korean Wood Science and Technology
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• 제35권2호
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• pp.51-60
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• 2007

In this study, the possibility of using pyrolysis oil as wood adhesives was explored. Especially, adhesives were formulated by reacting pyrolysis oil and formaldehyde and also partially replacing phenol with pyrolysis oil in phenol-formaldehyde (PF) adhesive and soy hydrolizate/PF adhesive formulation. The pine wood was fast pyrolyized and the oils were obtained from a series of condensers in the pyrolysis system. The oils from each condenser were first reacted with formaldehyde to explore potential use of the oil itself as adhesive. The lap-shear bond strength test results indicated that the oil itself could be polymerized and form bonds between wood adherends. The oils from each condenser were then mixed together and used as partial replacement of phenol (25, 33, and 50% by weight) in phenol-formaldehyde adhesive. The bond strength of the oil containing PF adhesives was decreased as percent phenol replacement level increased. However, no significant difference was found between 25 and 33% of phenol replacement level. The oil-contained PF resins at 25, 33, and 50% phenol replacement level with different NaOH/Phenol (Pyrolysis oil) molar ratio were further formulated with soy hydrolizate to make soy hydrolizate/pyrolysis oil-phenol formaldehyde adhesive at 6:4 weight (wt) ratio and used for fiberboard manufacturing. Surface internal bond strength (IB) of the boards bonded with 33% replacement at 0.3 NaOH/Phenol (Pyrolysis oil) molar ratio performed better than other replacement levels and molar ratios. Thickness swelling after 24 hr cold water soaking and after 2 hr in boiling water was increased as % replacement of pyrolysis oil increased.