• Food Science of Animal Resources
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• v.34 no.6
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• pp.808-814
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• 2014

This study investigated the effect of gum arabic (GA) combined with microbial transglutaminase (TG) on the functional properties of porcine myofibrillar protein (MP). As an indicator of functional property, heat-set gel and emulsion characteristics of MP treated with GA and/or TG were explored under varying NaCl concentrations (0.1-0.6 M). The GA improved thermal gelling ability of MP during thermal processing and after cooling, and concomitantly added TG assisted the formation of viscoelastic MP gel formation. Meanwhile, the addition of GA decreased cooking yield of MP gel at 0.6 M NaCl concentration, and the yield was further decreased by TG addition, mainly attributed by enhancement of protein-protein interactions. Emulsion characteristics indicated that GA had emulsifying ability and the addition of GA increased the emulsification activity index (EAI) of MP-stabilized emulsion. However, GA showed a negative effect on emulsion stability, particularly great drop in the emulsion stability index (ESI) was found in GA treatment at 0.6 M NaCl. Consequently, the results indicated that GA had a potential advantage to form a viscoelastic MP gel. For the practical aspect, the application of GA in meat processing had to be limited to the purposes of texture enhancer such as restructured products, but not low-salt products and emulsion-type meat products.

• Physical Therapy Korea
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• v.13 no.4
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• pp.30-38
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• 2006

This study was to investigate the influence of cooling on muscle force and viscoelastic properties of tendon structures in themedial gastrocnemius (MG) muscle. The subject was instructed to gradually increase force (10% MVC step) from a relaxed state to MVC within 3 s. At this time, it was measured by an ultrasonographic probe was attached and that an electrode was attached to monitor EMG. The F values at 50 100% of MVC were significantly greater under the cold condition than under the non-cold condition (p<.05). The ${\Delta}F/{\Delta}L$ values at 80~100% of MVC were significantly higher under the cold condition than under the non-cold condition (p<.05). The elongation under the non-cold condition had a tendency to be greater than that under the cold condition. The results suggest that cooling results in an increase in the stiffness of tendon structures with a reduction of muscle force and elongation.

• Journal of Adhesion and Interface
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• v.7 no.2
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• pp.12-18
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• 2006

Recently, as industries and technologies are increased, superior adhesives having more and more developed functions and properties have been demanded. In this article, to use the merits and viscoelastic properties of poly(ethylene/butylene) rubber resin and to supplement the demerits, semi-structure pressure sensitive adhesives (PSAs) are developed. Aslo, it can be said environmentally friendly PSAs because of not use the organic solvent and not emit volatile organic compounds (VOCs).

• Polymer(Korea)
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• v.35 no.3
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• pp.232-237
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• 2011

The relaxation spectra of polyacrylonitrile-poly(vinyl chloride) copolymer filament fibers were obtained by applying the experimental stress relaxation curves to the theoretical equation of relaxation spectrum. The theoretical equation of relaxation spectrum was derived from the Ree-Eyring and Maxwell model. The experimental of stress relaxation was carried out using a tensile tester with a solvent chamber. The determination of relaxation spectra was performed by computer calculation. From the relaxation spectra, the fine structures, viscoelastic properties and hole volumes of solid polymers were studied. It was observed that the relaxation spectra of these samples were directly related to the distribution of molecular weights and self diffusions of flow segments.

• Composites Research
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• v.19 no.3
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• pp.15-22
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• 2006

In this study, we prepared glass fiber reinforced polypropylene composites using Brabender twin-screw extruder. Compatibilizer, polypropylene-based maleic anhydride (PP-g-MAH), was used to increase the molecular interaction between polypropylene matrix and glass fiber and to enhance melt processability. We also measured the shear and uniaxial elongational behaviors of glass-fiber reinforced composites in the absence or presence of compatibilizer. The effects of compatibilizer and fiber loading on the viscoelastic behaviors were examined. It was fuund that the PP-g-MAH compatibilizer improved the fluidity and increased the molecular bonding of composite melts in shear flow. Transient elongational viscosity was increased with fiber loadings in uniaxial elongational flow However, it was decreased with increasing elongational rates because of microscale shear flow between fibers.

• The Korean Journal of Rheology
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• v.8 no.2
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• pp.129-138
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• 1996

접착강도는 접착제의 점탄성을 반영한 온도·속도 의존성을 나타낸다는 것이 잘 알 려져있다. 특히 유리전이온도(Tg)에서의 역학적 완화기구가 접착층의 변형을 수반하는 접착 층의 변형을 수반하는 접착강도에 크게 영향을 미치고 있다. 또한 접착계의 모드I의 변형에 너지 해방율(GIC)를 측정할때에도 접착제의 변형과 파괴가 발생하기 접착제의 점탄성이 그 값에 어떠한 영향을 미치는 지에 흥미가 깊다. 본 연구에서는 2종류의 에폭시 수지를 블랜 드한 접착제를 이용하여 일정한 측정조건에서 인장 접착강도와 GIC의 상관관계에 대하여서 도 토론하였다.

• Archives of Plastic Surgery
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• v.47 no.4
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• pp.301-304
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• 2020

Dermal injectables are the most popular material for facial enhancement, including volumizing and wrinkle correction. However, although hyaluronic acid is the most common component of dermal injectables, the character of hyaluronic acid products is quite variable. These materials can be described in terms of their viscoelastic properties using four parameters. In this article, the author would like to describe these properties in detail. Although many physicians consider this material to be convoluted, thoroughly understanding the characteristics of various injectables enables us to tailor procedures accordingly and to enhance the final results.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.85-86
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• 2013

• Structural Engineering and Mechanics
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• v.11 no.3
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• pp.273-286
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• 2001

Viscoelastic (VE) dampers have shown to be capable of providing structures with considerable additional damping to reduce the dynamic response of structures. However, the VE material appears to be sensitive to the variations in ambient temperature and vibration frequency. To minimize these effects, a new VE material has been developed. This new material shows less sensitivity to variations in vibration frequency and temperature. However, it is highly dependent on the shear strain. Experimental studies on the seismic behavior of a 2/5 scale five-story steel frame with these new VE dampers have been carried out. Test results show that the structural response can be effectively reduced due to the added stiffness and damping provided by the new type of VE dampers under both mild and strong earthquake ground motions. In addition, analytical studies have been carried out to describe the strain-dependent behavior of the VE damper. The dynamic properties and hysteresis behavior of the dampers can be simulated by a simple bilinear model based on the equivalent dissipated energy principle proposed in this study.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.911-914
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• 2005

Soft tissue characterization and modeling based on living tissues has been investigated in order to provide a more realistic behavior in a virtual reality based surgical simulation. In this paper, we characterize the nonlinear viscoelastic properties of intra-abdominal organs using the data from in vivo animal experiments and inverse FE parameter estimation algorithm. In the assumptions of quasi-linear-viscoelastic theory, we estimated the nonlinear material parameters to provide a physically based simulation of tissue deformations. To calibrate the parameters to the experimental results, we developed a three dimensional FE model to simulate the forces at the indenter and an optimization program that updates new parameters and runs the simulation iteratively. The comparison between simulation and experimental behavior of pig intra abdominal soft tissue are presented to provide a validness of the tissue model using our approach.