• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.124-128
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• 2009

In this study, the effect of multi-step purification or functionalization on physicochemical properties of multi-walled carbon nanotubes (MWNTs)/epoxy (EP) nanocomposites was investigated. The nanocomposites containing multi-step purified MWNTs showed a stronger influence on $T_g$ and increased in mechanical properties in comparison to nanocomposites containing the same amount of only purified MWNTs. Consequently, the multi-step purification of MWNTs led to an improvement of thermomechanical properties of nanocomposites, resulting from improving the intermolecular interaction of MWNTs in epoxy matrix resins.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.588-591
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• 2002

Radiation technology is an effective way for regulating polymeric materials to physicochemical and mechanical properties. The effect of radiation on mechanical and electrochemical properties of new rubber-like polymeric composite materials based on poly(vinyl ether of ethyleneglycol : PVEEG) have been studied for investigating mechanical and electric property of polymer composites applications.

• Nuclear Engineering and Technology
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• v.31 no.6
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• pp.39-50
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• 1999

The physicochemical, mineralogical, hydraulic, swelling and mechanical properties of a domestic bentonite for use as the buffer material in a high-level waste repository have been measured. The bentonite is identified to be a Ca-bentonite, and the hydraulic conductivity of the compacted bentonite with the dry density higher than 1.4 Mg/㎥ is lower than 10$^{-11}$ m/s When the dry densities are 1.4 to 1.8 Mg/㎥, the swelling pressures are in the range of 6.6 to 143.5 kg/$\textrm{cm}^2$. The unconfined compressive strength is about 94 kg/$\textrm{cm}^2$, and the coefficient of volume change and the coefficient of consolidation are in the range of 0.O0249 to 0.02142 $m^2$/MN and 0.018 to 0.115$m^2$/year, respectively.

• Transactions on Electrical and Electronic Materials
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• v.4 no.3
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• pp.25-28
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• 2003

Radiation technology is an effective way for regulating polymeric materials to physicochemical and mechanical properties. New polymeric hydrogels based on vinyl ethers have been synthesized by the $\gamma$-initiated polymerization method. In this paper, we have studied the effect of radiation on mechanical and electrochemical properties of new rubber-like polymeric composite materials based on polyvinylether of ethyleneglycol (PVEEG).

• Macromolecular Research
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• v.10 no.3
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• pp.168-173
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• 2002

Unstabilized low-density polyethylene (LDPE) films and films formulated with hindered amine light stabilizer (HALS) were exposed to UV-radiation; and the physicochemical changes during photooxidation processes have been investigated using tensile, FTIR spectre-photometric and thermal analytical (DSC) techniques. The dependence of tensile properties (elongation- and stress-at-break), carboxyl index and heat of fusion on UV-irradiation time have been discussed. The use of HALS is found to be effective in maintaining the UV-mechanical properties of the LDPE films. The experimental results showed that there exists no correlation between mechanical properties and carbonyl index, whereas crystallinity correlates well with carbonyl index in unstabilized and stabilized films for irradiation times greater than 100 h. The rate of formation of carbonyl groups is found to be dependent on UV exposure time. Crystallinity of the film samples is strongly influenced by both exposure time and presence of HALS.

• Journal of Biomedical Engineering Research
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• v.33 no.2
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• pp.89-97
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• 2012

The purpose of this study is to develop the guideline of the physicochemical and mechanical properties evaluation for silicone gel filled breast implants. First of all, the use and development status for silicone gel filled breast implants were investigated, and then, standard and criteria about performance evaluation established by the international organizations such as ASTM, FDA guidance and ISO were examined. To evaluate the mechanical properties, data research and testing for breaking strength, elongation, tensile set, joint intensity, silicone gel cohesion, weight loss from heating, static rupture resistance, impact resistance test, fatigue test, and gel bleed were performed. On the other hand, to evaluate the physicochemical properties, volatile matter, extent of cross linking, heavy metals, and extractable were analyzed. In this study, results for general function, mechanical properties and physicochemical properties were examined and reviewed for the accordance with international standard, and objective and standardized guideline was provided.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.6
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• pp.485-497
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• 2001

For a period of 5 days, the quality of breads with Paecilomyces japonica powder were investigated using chemical, sensory, and mechanical evaluations at $25^{\circ}C$. The result of analysis of chemical properties revealed that the pH value of dough was increased as the amount of Paecilomyces japonica powder increased, but volume of dough and baking loss rate were decreased. Breads with 1% and 2% Paecilomyces japonica powder showed a good overall preference in sensory evaluation. As storing time passed. moisture content, lightness, and redness were decreased in all breads, but yellowness increased. Hardness and gumminess of texture analysis were increased as storing time passed, but springiness decreased. Springiness of the mechanical properties was negatively correlated with pH value of dough and volume of bread, while was positively correlated with volume of dough and baking loss rate. In the analysis of correlation between sensory and mechanical properties showed that hardness of mechanical properties had negative correlation with softness, moistness, and springiness. Cohesiveness of mechanical properties had positive correlation with acceptability.

• Animal Bioscience
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• v.37 no.2
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• pp.274-283
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• 2024

Objective: The aim of the study was to evaluate the physicochemical properties (nutrient composition, pH, water content and activity, sorption properties) and mechanical properties (compression force and energy) of granulated feed mixtures with various inclusion levels of crude fibre concentrates ARBOCEL and VITACEL for broiler chickens, i.e. +0.0% (control group - group C), +0.3%, +0.8%, +1.0%, +1.2%. Methods: The feed mixtures were analyzed for their physicochemical properties (nutrient composition by near-infrared spectroscopy, pH with the use a CP-401 pH meter with an IJ-44C glass electrode, water content was determined with the drying method and activity was determined with the Aqua Lab Series 3, sorption properties was determined with the static method) and mechanical properties (compression force and energy with the use TA-HD plus texture analyzer). The Guggenheim-Anderson-de Boer (GAB) model applied in the study correctly described the sorption properties of the analyzed feed mixtures in terms of water activity. Results: The fibre concentrate type affected the specific surface area of the adsorbent and equilibrium water content in the GAB monolayer (p≤0.05) (significantly statistical). The type and dose of the fibre concentrate influenced the dimensionless C and k parameters of the GAB model related to the properties of the monolayer and multilayers, respectively (p≤0.05). They also affected the pH value of the analyzed feed mixtures (p≤0.05). In addition, crude fibre type influenced water activity (p≤0.05) as well as compression energy (J) and compression force (N) (p≤0.001) (highly significantly statistical) of the feed mixtures. Conclusion: The physicochemical analyses of feed mixtures with various inclusion levels (0.3%, 0.8%, 1.0%, 1.2%) of crude fiber concentrates ARBOCEL or VITACEL demonstrated that both crude fiber types may be used in the feed industry as a feedstuff material to produce starter type mixtures for broiler chickens.

• Food Engineering Progress
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• v.15 no.1
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• pp.70-74
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• 2011

The effects of high pressure homogenization (microfluidization) on physicochemical properties of normal maize and oxidized maize starch film were studied. The molecular dispersibility of amlyose and amylopectin and the disintegration of granular structure had a marked effect on the physicochemical properties of starch films. The high pressure homogenized starch films showed increased solubility and transmittance due to the absence of gelatinized starch granules. The tensile strength of starch film increased significantly with decreasing oxygen permeability after high pressure homogenization, indicating that starch molecules were more uniformly and fully dispersed during the film formation. As a result, a clear starch film with improved mechanical properties was obtained after high pressure homogenization due to the increased interactions between the uniformly dispersed starch molecules.

• The Korean Journal of Food And Nutrition
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• v.23 no.3
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• pp.419-427
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• 2010

The focus of the current study was to investigate the physicochemical properties of a corn starch-sponge matrix prepared at a low concentration below gel forming by freeze-drying. The effect of variables(starch concentration, heating temperature, and heating hold time) on the physicochemical properties of the samples was analyzed by response-surface methodology. Regression models on the properties of samples such as hardness, springiness, and water solubility index(WSI) showed high correlation coefficients(r>0.95) and significant F values, but regression models for the other properties(swelling power, apparent viscosity, reducing sugar content, and digestibility) showed them to have relatively low significance. Sample hardness of sample showed the highest value at condition of $90^{\circ}C$ and 5%, whereas springiness was at a maximum at $130^{\circ}C$ and 5%. Also, at 1% of starch concentration, mechanical properties were greatly decreased as the relative humidity increased, compared with the 3% and 5%, especially in the hardness of samples. The WSI showed an increasing trend with heating temperature regardless of starch concentration. Overall, the physicochemical properties of freeze-dried corn starch-sponge matrix were influenced much more by starch concentration and heating temperature than by heating hold time. The results of this study show that the basic properties of freeze-dried corn starch-sponge matrix can be used for the specific food applications or as a functional material for its stability.