• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.331-332
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• 2007

In this work, the TiO2 pigment influence in HDPE dielectric strength was analyzed. Chemical and structural characterizations were made to identify changes during the processing and your influence in the electrical properties, formulations containing 0, 0.5, 1, 2.5, 4 and 6 of titanium dioxide were processed by extrusion and injection molding with stabilization-antioxidants, ultraviolet stabilizers and plasticizers. The electrical strength tests were analyzed by the statistical distribution of Weibull, and the maximum likelihood method. The high concentrations present lower values to electrical strength. The parameter could be using to insulator panicles dispersion. The TiO2 concentration variation shows that these incorporations implicate strength values increase has a maximum (5,35MV/cm). High pigment concentration induces a little falls in property values. Observing the parameter, minimum experiment electric field (Ebmin) and electric strength value, found that the best electric perform formulation was the formulation with 2.5% TiO2 weight.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.238-243
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• 2002

The effects of concentration and temperature on degradation of anthocyanins of purple-fleshed sweet potato pigment concentrate and a Japanese plum juice were determined over temperature ranges of 60 to $90^{\circ}C$ and 5 to $60^{\circ}C$, respectively. Degradation of anthocyanins in pigment concentrates followed the first-order reaction rate. Activation energies of the pigment solutions ranged 51.29-73.02 kJ/mol, linearly decreasing as concentration increased except the pigment solution of $8.4^{\circ}Brix$ which was not concentrated after extraction. Anthocynins in Japanese plum juice was also degraded by the first-order reaction kinetics with activation energy of 75.80 kJ/mol. Storage life of the beverage was extended with decreasing storage temperature. Pigment was ratained more than 80% until 8 months storage at $5^{\circ}C$.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.8
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• pp.1169-1177
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• 2006

The aim of this study was to investigate the change of the weight loss, tensile strength, flex stiffness, and color-values of the pigment-dyed cotton, polyester/cotton, polyester and nylon fabrics after washing process. Pigment-dyed cotton and polyester/cotton fabrics were treated with the cellulase, of which concentrations were 0, 1, 3 and 5g/l. The time of washing process ranges from 30 to 120 minutes. Pigment-dyed polyester and nylon fabrics were treated without enzyme, of which the washing temperature were 13, 30, $55^{\circ}C$ and the washing time ranges from 30 to 120 minutes. Also, they were tested in terms of the influences of agitation speed(rpm) and additives such as softeners, enzymes, detergents. The weight loss and tensile strength of the pigment-dyed cotton and polyester/cotton fabrics were positively correlated with the concentration of cellulase and washing time. Neither polyester nor nylon fabrics exhibited any change of the weight. All fabrics showed the decline of flex stiffness and decoloration after washing process. Decoloration of cotton and polyester/cotton fabrics was due to both the influence of cellulase and the mechanical rubbing. On the other hand, that of polyester and nylon fabrics was caused by the mechanical rubbing only.

• Journal of Powder Materials
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• v.28 no.1
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• pp.38-43
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• 2021

A high NIR-reflective black pigment is developed by Mn doping of Fe2O3. The pigment powders are prepared by spray pyrolysis, and the effect of the Mn concentration on the blackness and optical properties is investigated. Mn doping into the crystal lattice of α-Fe2O3 is found to effectively change the powder color from red to black, lowering the NIR reflectance compared to that of pure Fe2O3. The pigment doped with 10% Mn, i.e., Fe1.8Mn0.2O3, exhibits a black color with an optical bandgap of 1.3 eV and a Chroma value of 1.14. The NIR reflectance of the prepared Fe1.8Mn0.2O3 black pigment is 2.2 times higher than that of commercially available carbon black, and this material is proven to effectively work as a cool pigment in a temperature rise experiment under near-infrared illumination.

• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.283-289
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• 1998

A bacterial strain KH-95 producing a high concentration of red pigment was isolated from the soil. The strain KH-95 was identified as a strain of Serratia sp. based on morphological and physiological characteristics. The optimal temperature and initial pH range for the production of pigment were 28$^{\circ}C$ and 7.0-8.0, respectively. The red pigment was purified through solvent extraction and silica gel column chromatography. Analyzing the structure of this pigment by instrumental analysis, it was identified as prodigiosin-like compound. In optimization of carbon and nitrogen sources, all carbon sources tested in this work inhibited the production of pigment except oils. Casein fumed out to be the most suitable nitrogen source for pigment production. Other nitrogen sources such as yeast extract, beef extract and peptone showed good cell growth but potently inhibited the production of pigment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.821-826
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• 1998

Functional properties of mucilage and pigment extracted from Opuntia ficus-indica var. saboten were determined at various temperatures, pHs and alcohol concentrations. The crude mucilage extracted from pickly pear showed pH 4.2, 0.14% total acidity and 8.1% total soluble solid content(w/w, wet basis). Polysaccharide was purified from mucilage extract by isopropanol precipitation. Intrinsic viscosity of polysaccharide was 18.1dl/g and decreased with increasing KCl concentration. Relative viscosity and color stability of mucilage extract were determined with capillary viscometer and spectrophotometer at 534nm, respectively. In additions of 1~20%(v/v) ethanol, the red pigment of mucilage extract was very stable, but relative viscosity, increased gradually. For heating above 7$0^{\circ}C$, the stability of red pigment decreased drastically, but rheological property of mucilage was not changed. During storage, the red pigment was extremely unstable at above pH 8.3. At both pH 3.0 and pH 4.2, the red pigment was the most stable at 4$^{\circ}C$ for 18 days. In the case of storage at 37$^{\circ}C$, pigment of mucilage extract at pH 3.0 was destroyed more quickly than that at pH 4.2. Natural mucilage extract(pH 4.2) showed the good stability of red pigment at 3$0^{\circ}C$ for 10 days.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.129-130
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• 2002

Monascus pigment was produced by Monascus species. During Monascus fermentation, citrinin, the mycotoxin was produced with pigments. Citrinin can become a problem for use of monascus pigment as a food colorant. We found adding of S. cerevisiae filtrate during Monascus cultivation could enhance production of red pigment whereas it could reduce citrinin level. When we added the filtrate at 24 hand 48 h, respectively, pigment production increased about 400% and citrinin concentration decreased to 30%. In a glucose medium, there was no special effect by addition of filtrate. On the other hand, the effect was striking in a sucrose medium.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.5
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• pp.18-38
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• 2002

A previous study on the model coatings based on latex-bound plastic pigment coatings (1) has been extended to latex-bound No. 1 clay, ultra-fine ground calcium carbonate (UFGCC), and clay-carbonate pigment mixture coatings, which are being widely used in the paper industry. The latex binder used was a good film-forming, monodisperse S/B latex or 0.15$\mu\textrm{m}$. No. 1 clay was representative of plate-like pigment particles, whereas UFGCC was of somewhat rounded rhombohedral pigment particlel. Both of them had negatively skewed triangular particle size distributions having the mean particle suet of 0.7${\mu}{\textrm}{m}$ and 0.6$\mu\textrm{m}$, respectively. Their packing volumes were found to be 62.5% and 657%, respectively. while their critical pigment volume concentrations (CPVC's) were determined to be 52.7% and 50.5% ( average of 45% caused by the incompatibility and 55.9% extrapolated) by coating porosity, respectively. Each pigment/latex coating system has shown its unique relationship between coating properties and pigment concentrations, especially above its CPVC. Notably, the clay/latex coating system hat shown higher coating porosity than the UFGCC/latex system at high pigment concentrations above their respective CPVC's. It was also found that their coating porosity and gloss were inter-related to each other above the CPVC's, as predicted by the theory. More interestingly, the blends of these two pigments have shown unique rheological and coating properties which may explain why such pigment blends are widely used in the industry. These findings have suggested that the unique structure of clay coatings and the unique high-shear rheology of ground calcium carbonate coatings can be judiciously combined to achieve superior coatings. Importantly, the low-shear viscosity of the blends was indicative of their unique packing and coating structure, whereas their high-shear rheology was represented by a common mixing rule, i.e., a viscosity-averaging. Transmission and scanning electron and atomic force microscopes were used to probe the state of pigment / latex dispersions, coating surfaces, freeze fractured coating cross-sections, and coating surface topography. These microscopic studies complemented the above observations. In addition, the ratio, R, of CPVC/(Pigment Packing Volume) has been proposed as a measure of the binder efficiency for a given pigment or pigment mixtures or as a measure of binder-pigment interactions. Also, a mathematical model has been proposed to estimate the packing volumes of clay and ground calcium carbonate pigments with their respective particle size distributions. As well known in the particle packing, the narrower the particle size distributions, the lower the packing volumes and the greater the coating porosity, regardless of particle shapes.

• Korean Journal of Food Science and Technology
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• v.33 no.2
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• pp.221-225
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• 2001

Flow properties of red flower cabbage pigment solutions were determined over a wide range of temperatures ($20-50^{\circ}C$) and soluble solid concentrations (1-65%) using a cone and plate rotational viscometer. Flow properties of the pigment solutions were adequately described by the simple power law model. Within the tested ranges of concentration, temperature and shear rate, the flow behavior index (n) and the consistency index (K) of the solutions were in the ranges of 0.841-0.998 and $0.008-31.525\;Pa{\cdot}s^n$, respectively. The effect of temperature on the apparent viscosity of the solutions followed an Arrhenius type relationship. Activation energy of flow varied from 9.36 to 52.48 kJ/mol depending on the solid concentration and shear rate. The combined effect of temperature and concentration on the apparent viscosity at the shear rate of $100\;s^{-1}$ could be represented by a single equation as ${\ln}\;{\eta}_a\;=\;6.11\;-\;3103.94(1/T)\;-\;0.03C$.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.541-545
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• 2002

Stability of Monascus pilosus pigment was investigated under various conditions. The concentration of the pigments stored under air and sub-atmosphere (250 mmHg) for 30 days at room temperature decreased by 77.9% and 48.4%, respectively. The pigment solution was stable under temperature ranges of $20-80^{\circ}C$, pH 4-8, darkness and presence of KCl, NaCl, $CaCl_2$, $MgCl_2$, and $ZnCl_2$. In contrast, the pigment solution was relatively unstable, decreasing in concentration by 6.0 and 11.6% at 100 and $121^{\circ}C$, 15.5 and 13.7% at pH 3 and 9, 22.9 and 66.8% under fluorescence and sun light, respectively, and 20.2% in the presence of $AlCl_3$.