• Elastomers and Composites
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• v.53 no.4
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• pp.195-201
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• 2018

Three kinds of rubber compounds were prepared, and their underwater acoustical properties were investigated for anechoic coating. Dynamic mechanical properties of the rubber compounds were measured using a dynamic mechanical analyzer and extended to 100 kHz using time-temperature superposition. The sound speed, reflection coefficient, and attenuation constant were calculated. Silicone rubber showed the lowest reflection coefficient, and nitrile rubber showed the highest attenuation constant. The acoustic properties of nitrile rubber compounds with various compositions were investigated. The sound speed, reflection coefficient, and transmission coefficient of the nitrile rubber in the frequency range of 200-1000 kHz were measured in a water-filled tank.

• Elastomers and Composites
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• v.58 no.4
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• pp.173-178
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• 2023

Recently, there has been a significant focus on the development of flexible and stretchable sensors, driven by advancements in electronic devices and the robotics industry. Among these sensors, tactile sensors stand out as the most actively researched, playing a crucial role in facilitating interaction between humans and electronic devices, particularly in robotics and medical applications. This study specifically involves the manufacturing of a capacitive tactile sensor using a relatively straightforward process and sensor structure. Natural rubber and Nitrile butadiene rubber, commonly employed in the rubber industry, were utilized. The dielectric material in the manufactured tactile sensor possesses a porous structure. Notably, the resulting tactile sensor demonstrated excellent sensitivity, approximately 1%/kPa, and exhibited the capability to detect pressures up to 212 kPa.

• Elastomers and Composites
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• v.44 no.3
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• pp.260-268
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• 2009

Modification of clay surface was attempted by treating the clay with bis[(3-triethoxysilylpropyl)tetra sulfide (TSS) to raise the hydrophobicity and to induce a chemical reaction between the clay and the high temperature vulcanization-type silicone rubber matrix with purpose of improving the compatibility between the components, and thereby Na-$MMTS_4$ and Fe-$MMTS_4$ were synthesized by treating Na-MMT and Fe-MMT with TSS, respectively. Silicone rubber/clay composites were prepared by compounding the clays with silicone rubber. Thermal stability and mechanical properties were evaluated as a function of the clay types and the surface modification.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.93-102
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• 2021

This study aims is to determine the factors that influence Indonesian rubber export supply based on the export destination countries. Indonesian rubber export supply is thought to be influenced by the variables like the volume of Indonesia rubber exports, the price of Indonesian natural rubber, the volume of domestic rubber production, the export volume of the previous period, the rupiah exchange rate against US$, the interest rate and real Gross Domestic Product (GDP). The data used is the annual time series from 1995-2015 based on export countries encompassing the United States, China, and Japan. Multiple linear regression with the Ordinary Least Square (OLS) method is applied to analyse the data. The results showed that the volume of Indonesian rubber exports to China is not influenced by domestic natural rubber prices and the Rupiah exchange rate against the Chinese Yuan. The volume of Indonesian rubber exports to Japan is influenced by the volume of domestic rubber production. The volume of Indonesian rubber exports to the three destination countries is influenced by the volume of domestic rubber production, interest rate, and real GDP.

• Journal of Forest and Environmental Science
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• v.38 no.2
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• pp.75-89
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• 2022

The negative impact of monoculture rubber plantations on biodiversity and associated ecological processes/ecosystem services has led to suggestions on the use of integrated land use systems for rubber cultivation and production in order to ensure environmental sustainability. However, there is paucity of information on the effect of such integrated land use systems on the diversity and abundance of the rubber plantation undergrowth. We evaluated and compared undergrowth plant species composition, richness, abundance, diversity and interaction, in three integrated systems (Rubber-Strelitzia reginae Integrated System - RSrIS, Rubber-Podocarpus nagi Integrated System - RPnIS & Naturally Managed Rubber Plantation - NMRP) with three Rubber Monoculture Plantations (RMP₁, RMP₂ & RMP₃) adjacent to the integrated systems, respectively, at the Investigation and Experiment Station of Tropical Crops, Danzhou, Hainan, China. Undergrowth species density was higher in the rubber monocultures than in the integrated systems except in RSrIS. Species richness and diversity were also higher in the monocultures except in NMRP. Species similarity/interaction between the monocultures and the integrated systems was highest between RMP₃ and NMRP. The NRMP proved to be the best model of natural rubber integrated system for the conservation of undergrowth species richness, diversity and interspecific interaction. However, the conservation of undergrowth species in other forms of integrated natural systems can be enhanced by considering the ecology of species to be integrated in terms of their growth characteristics, competitive nature, and ability to grow in association with other species.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.106-109
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• 2001

In this work, we investigate the toughening mechanism of the rubber-modified epoxy resin. The fracture toughness($K_{IC}$) is measured using CT specimens for three kinds of rubber-modified epoxy resin with different rubber content. The damage zone and rubber particles around a crack tip of a damaged specimen just before fracture are observed by a polarization microscope and an atomic force microscope(AFM). Both the fracture energy($G_{IC}$) and the size of damage zone increase with the rubber content below l5wt%. The size of the rubber particles can be qualitatively correlated with the $G_{IC}$ and the size of damage zone. The cavitation of the rubber particles inside the damage zone is observed, which is expected to be main toughening mechanism by rubber particles. the stress which causes the cavitation of rubber particles is estimated by the Dugdale model.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.441-446
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• 2004

Mechanical systems with rubber parts have been used widely in industry fields. The evaluation of the physical characteristics of rubber is important in rubber application. Rubber material is useful to machine component for excellent shock absorbing characteristics. The impact characteristics of rubber were examined by experimental and finite element method. The impact test was conducted with a free-drop type impact tester. The ABAQUS/Explicit was used for finite element analysis. The effects of thickness and diameter of the cylindrical rubber structures were investigated. The impact absorbing ratio of the rubber material was studied order to compare the peak reaction force of the specimen which only contained aluminum against the specimen with the inserted rubber part.

• Elastomers and Composites
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• v.53 no.2
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• pp.80-85
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• 2018

Chloro isobutylene isoprene rubber (CIIR) and ethylene propylene diene monomer (EPDM) compounded with other formulation chemicals, depending on the polymer blend, were prepared by mechanical mixing. After manufacturing the rubber vulcanizate by compression molding with a hot press, the mechanical and thermal properties including thermal conductivity, rebound resilience of the CIIR/EPDM blends were measured. As the EPDM rubber content increased, hardness and tension set showed a tendency to increase. Pure CIIR exhibited the lowest tensile strength; however, tensile strength increased with loading of EPDM rubber. On the other hand, in CIIR rubber, which is usually a low-rebound elastomer owing to a high damping effect, rebound resilience exhibited an increasing trend as the content of EPDM rubber increased. As the EPDM rubber content increased, thermal stability was improved due to reduction of decomposition rate in the rubber region of the blend vulcanizate.

• Journal of the Semiconductor & Display Technology
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• v.23 no.1
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• pp.104-109
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• 2024

In this paper, we propose structures of a socket that can improve signal transmission characteristics compared to the existing silicone rubber socket. A coaxial rubber socket was proposed to improve signal distortion due to electromagnetic interference between signal lines. And an air gap rubber socket was proposed to improve the degradation of reflection characteristics due to high dielectric constant. Using a 3D electromagnetic field simulator, the S-parameter and crosstalk of the three sockets were compared and the signal transmission characteristics were analyzed. In both coaxial rubber socket and the air gap rubber socket, S-parameter and crosstalk were improved compared to the silicone rubber socket. Among them, the air gap rubber socket was the best for S-parameter, and the coaxial rubber socket was the best for crosstalk.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.9_10
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• pp.1093-1100
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• 2003

Following a treatment with edible oils and/or washing, the tensile properties of vulcanized rubber were measured to assess the effect of the sorbed edible oil. Rubber soiled with soybean oil, after 8 weeks storage in a 30$^{\circ}C$ incubator, retained 61% of its original strength, and rubber soiled and washed retained the 73%. The strength of the rubber soiled with oil decreased remarkably during the first 2 weeks. After repeating this soiling and/or washing 7 times, the soiled rubber had only 16％ of its original strength, the rubber soiled and washed had 45%. In all cases, breaking elongations were not decreased as much as tensile strengths; therefore , more of the elasticity of the rubber remained than did the strength. From these results it is concluded that washing after soiling with oils is very helpful in maintaining the strength of rubber. In this study, three different surfactant solutions, AS, AE and AS/AE, were used. In the AS solution, the contact angle of the soybean oil was greater and the work of the detergency was the smaller than in either the AE or the AS/AE solution, the loss of the strength of the rubber washed in AS solution did not decrease significantly. These results suggest that rolling-up, emulsification and solubilization also participate in the removal of oil from rubber.