• Elastomers and Composites
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• v.35 no.3
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• pp.196-204
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• 2000

SBR, polyurethane, acryl and epoxy latex were separately mixed with ethylene -vinylacetate emulsion(EVA) in the range of $0{\sim}50wt%$. For the mixtures, the various physical properties such as defoamerability, mechanical property, and water resistance were experimentally examined. The excellent defoamer was BYK-021 and the appropriate use of it was 0.3 phr for the total components. The shrinkage of compounds was influenced by the compatability of resins and the formation of voids. The mechanical properties was related to the cohesive force of resin particles, the coagulation of cement particles and the co-bonding of resin particles with cement particles. Mixing latex separately showed better properties then non-mixing in the shrinkage ratio, flexural strength, adhesive strength, and impact strength. The water resistance of composites mixed with cement was worse than that of EVA resin.

• Elastomers and Composites
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• v.39 no.1
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• pp.51-60
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• 2004

The cure, viscoelastic and mechanical characteristics of organoclay filled NR/BR blends were studied and compared with the properties of carbon black and silica filled NR/BR blends. The nanocomposites with extensive exfoliation state can be fabricated by a solution mixing method. In the composites, the amount of filler content was fixed to 10 phr. Degree of intercalation and exfoliation was characterized by X-ray diffraction (XRD). XRD results indicated exfoliation of the silicate layers into the rubber matrix. While the degree or intercalation and exfoliation is lowered by the conventional mixing method, extensive exfoliation can be obtained by the solution mixing method. It was found that the clay filled NR/BR compound showed better viscoelastic (tan ${\delta}$) and mechanical properties than the carbon black or silica filled NR/BR compounds.

• Resources Recycling
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• v.14 no.3
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• pp.55-62
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• 2005

Mechanical properties of shell powder containing mixed recycled plastics were investigated depending on the shell content and surface modification. First, shell powder and LDPE were compounded using the twin screw extruder to manufacture 40 wt% master batch(M/B), and the M/B was blended with LDPE to produce bulk specimens with 10, 20, 30 and 40 wt% shell content. To improve the compatibility of shell powder with mixed recycled plastics matrix, surface of shell powder was chemically modified with cations or cationic surfactant. Surface modified shell was also used to prepare bulk specimens with the same shell content. Mechanical property analysis showed obvious improvement for the surface modified shell containing bulk specimens compared to unmodified ones. These results can lead to the development of new applications for the mixed recycled plastics.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1285-1294
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• 1998

Whey powder, a by-product of milk industry, was utilized to produce biopolymer film with the combination of film matrix supporting material, sodium caseinate. Biopolymer films were prepared from whey powder-sodium caseinate mixtures at several mixing ratios. The effects of pH, plasticizers and cross-linkers on tensile strength (TS) and elongation (E) of films were investigated. The films could be formed by use of whey powder up to 70%. As the whey powder content was increased, TS of the film decreased while E increased. Films containing more than 70% of whey powder could not be formed due to the stickiness of lactose in whey powder. The optimum pH of the film solution was found to be 10. Among the plasticizers tested, sorbitol was found to be the most effective plasticizer while glycerol was inadequate for the film. Tensile strengths of films containing $30{\sim}40%$ whey powder were higher than 10 MPa with relatively high E, when the films were plasticized with 30% (w/w) and 40% sorbitol. TSs of the relatively weak films containing $50{\sim}60%$ whey powders were improved by the addition of small amount of sodium citrate for 30% sorbitol plasticized films, and by the addition of sodium chloride for 40% sorbitol plasticized films. It was concluded that up to 70% of whey powder could be utilized to produce biopolymer films by adding sorbitol and cross linkers at pH 10.

• Journal of the Korean earth science society
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• v.35 no.6
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• pp.401-411
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• 2014

In order to enhance the Au Ag leach rate, a mechanochemical activation process and a mixed thiourea-thiocyanate solution has been applied to Au concentrate. To achieve mechanochemical activation, the Au concentrate was mechanically ground using a dry and a wet process. The results of a particle size distribution analysis and an XRD analysis, average particle size and crystallite size were much smaller in the dry-sample than in the concentrate sample. As well the size was smaller in the wet-sample than in the dry-sample. In SEM and XRD analysis, the amorphization effect was observed in the wet-sample due to mechanochemical activation. Au Ag leaching experiments were carried out with a thiourea solution, a thiocyanate solution and a mixed thiourea-thiocyanate solution. The Au Ag leach rate was much greater in the dry-ground-sample than in the concentrate sample, and the leach rate was greater in the wet-ground-sample than in the dry-sample. The Au Ag leach rate was much greater in the thiocyanate solution than in the thiourea solution, and the leaching rate was much greater in the mixed thiourea-thiocyanate solution than in the thiocyanate solution. Up to a 99% leach rate for Au Ag were only achieved in the wet-sample using the mixed thiourea-thiocyanate leaching solution.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.90-90
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• 2010

Cycloaliphatic Epoxy와 Bisphenol Epoxy를 각각 mol-wt%비 (80:20, 50:50, 20:80)로 혼합하고 Epoxy Silaned Silica, 바ed Silica, Spherical Silica, ATH(Aluminum Trihydrate)를 충진하여 내트래킹 특성 및 인장강도, 충격강도 등의 기계적 강도를 비교하였다. Cycloaliphatic 수지는 Huntsman사(社)의 CY5622, Bisphenol 수지는 Hexion사(社)E의 Epikote2200을 사용하였으며, Silaned Silica 및 Fused Silica는 Quatzwerke사(社)의 W12, FW12를 사용하였다. 전체 혼합물 중, 에폭시는 약 36%, 실리카는 약 34~540%, ATH는 약 10~30% 이다. 실험결과, ATH 함량이 높은 조성 및 Epoxy Silaned Silica를 사용한 조성과 Cycloaliphatic 혼합비율이 높은 조성이 우수한 내트래킹 특성을 보였다. 또한, Silica의 함량이 증가할수록 기계적 강도가 증가하였으며, Silaned Silica를 사용하였을 때 가장 우수한 특성을 나타내었다. 본 실험의 결과를 통해 옥외용 내트래킹 특성 규격인 IEC60587 4.5kV/6h를 만족하는 조성에 대해 가늠이 가능하였고, 각 조성에 따른 기계적 강도의 확인이 가능하였다.

• Polymer(Korea)
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• v.25 no.3
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• pp.343-348
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• 2001

The mechanical and the platelet adhesion properties of the fluorinated polyurethane elastomers synthesized with a perfluorinated polyether diol (Fomblin ZDOL$ZDOL^{(R)}$) and 4,4'-diphenyl methane diisocyanate (MDI) were investigated. The change of mechanical properties with the Fomblin content and the type of the polyether diol was investigated by applying a designed technique using in vitro platelet adhesion test. As a result, the tensile properties were affected by the content and the type of nixed polyether diols. Also the platelet adhesion of polyurethane elastomers decreased with increasing the extent of fluorination in the polymer.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.620-625
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• 1993

This experiment was carried out to predict the sensory properties of yogurt by instrumental methodology. Sensory attributes such as viscosity, mouth-feel, taste and quality were investigated. Instrumental parameters were measured with refractometer, viscometer, consistometer and rheometer. Sensory data showed that viscosity of peach yogurt was higher than that of strawberry and tropical-fruit-mixed (TFM) yogurts (p<.05). All instrumental parameters of peach yogurt were higher than those of strawberry and TFM yogurts, except cohesiveness and elasticity (p<.05). Viscosity measured by panelists was significantly correlated with instrumental viscosity, consistency, hardness, adhesiveness and gumminess in the fruit yogurts (p<.05). But mouth-feel and quality of yogurts showed poor relationships with instrumental parameters. The effective instrumental parameters for predicting sensory viscosity ($Y_{1}$) of yogurts were consistency ($X_{1}$), viscosity ($X_{2}$) and cohesiveness ($X_{3}$). And those for predicting mouth-feel ($Y_{2}$) were consistency. The estimated regression equations were as follows; $Y_{1}=4.968-0.0486X_{1}+0.00012X_{2}+0.0348X_{3},\;Y_{2}=5.701+0.0154X_{1}$.

• Journal of the Korean Wood Science and Technology
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• v.22 no.2
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• pp.46-53
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• 1994

This study was conducted to investigate a feasibility of manufacturing wood fiber thermoplastic composites and to evaluate their mechanical properties. Wood fiber as a potential reinforcing filler was compounded with two thermoplastics (polypropylene and high density polyethylene) in high intensity thermokinetic plastic mixer aided with a wetting agent. It was found that wood fiber thermoplastic composites could be manufactured by injection molding process. The tensile and flexural strength of injection molded specimens were improved greatly with increasing wood fiber concentration. Tensile and flexural modulus increased proportionately with wood fiber concentration. Wood fiber provided reinforcement with thermoplastics in terms of strength and modulus. However, the percent elongation at break and energy to break were reduced with increasing wood fiber loadings. Impact strength also showed similar trend.

• Composites Research
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• v.36 no.6
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• pp.408-415
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• 2023

The formation of bonding configurations such as pyridinic-N, pyrrolic-N, and graphitic-N by nitrogen doping plays a crucial role in imparting distinct physical properties to carbon nanomaterials. In this study, we propose a simple and cost-effective approach to regulate nitrogen dopant configurations in carbon nanotubes (CNTs) by mixing melamine as a dopant source. We employed three distinct mechanical mixing techniques, namely magnetic stirring, bath sonication and tip sonication. The higher the ratio of melamine to CNT, the higher the ratio of Pyrrolic-N, and when mixed through stirring, the highest ratio of Pyridinic-N was shown. The facile method proposed in this study, which can easily form various types of nitrogen dopants in carbon nanotubes, is expected to facilitate the application of nitrogen-doped carbon nanomaterials.