• Journal of the Korean Society of Food Culture
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• v.12 no.5
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• pp.469-475
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• 1997

The modification of rice powder was attempted by treatment of acetic acid and epichlorohydrin to improve the functional properties of baby food. The initial gelatinization temperature of rice powder determined by amylograph was decreased from $79.5^{\circ}C$ to $63^{\circ}C$ by modification. The apparent and maxium viscosity of rice paste at $95^{\circ}C$ before and after modification were increased from 92B.U. to 236B.U. and from 100B.U. to 202B.U., respectively. The light transmittance of modified rice paste was increased from the temperature of $60^{\circ}C$ and by increasing the degree of substitution at the fixed temperature, while decrease more or less by the treatment of epichlorohydrin. The degree of retrogradation of the paste was decreased from 28.7 to 18.0 upon modification. The rate of syneresis of modified rice powder was decreased with increasing the drgree of substitution and ,the extend of epichlorohydrin treatment. Syneresis was not observed when acetylated rice powder whose DS value is 0.048 was treated with 0.25% of epichlorohydrin for the formation of cross-linkage. The addition of modified rice powder in preparation of semi-solid type infant food could improve the quality without lowering overall digestibility.

• Journal of Powder Materials
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• v.18 no.4
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• pp.365-371
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• 2011

In this study, gradient porous Al-Cu sintered body was fabricated by powder metallurgy processing. Al-Cu powder mixtures were prepared by low energy ball milling with various milling time. After ball milling for 3h, the shape of powder mixtures changed to spherical type with size of 100~500 ${\mu}m$. Subsequently, Al-Cu powder mixtures were classified (under 150, 150~300 and over 300 ${\mu}m$) and compacted (20, 50 and 100 MPa). Then, they were sintered at $600^{\circ}C$ for various holding time (10, 30, 60 and 120 min) in $N_2$ atmosphere. The sintered bodies had 32~45% of porosity. As a result, the optimum holding time was determined to be 60 min at $600^{\circ}C$ and sintered bodies with various porosity were obtained by controlling the compacting pressure.

• Journal of Powder Materials
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• v.12 no.6 s.53
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• pp.387-392
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• 2005

The p-type semiconductor $Bi_2Te_3-Sb_2Te_3$ thermoelectric materials were fabricated by melting, milling and sintering process and their thermoelectric properties were characterized. The compound materials were ball-milled with milling time and the powders were sintered by spark plasma sintering process. The ball milled powders had equiaxial shape and approedmately $1\~3{\mu}m$ in size. The figure of meritz of sintered thermoelectric materials decreased with milling time because of lowered electrical resistivity. The thermoelectric properties of $Bi_2Te_3-Sb_2Te_3$ materials have been discussed in terms of electrical property with ball mill process.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.707-713
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• 2017

Saccharina japonica is a type of seaweed rich in dietary fiber, iodine, calcium, and selenium. We investigated the quality characteristics and antioxidant activities of gruel made with S. japonica powder, and identified the best ratio of powder to gruel to maximize its health effects. The gruel was prepared with rice, glutinous rice, GABA (${\gamma}-aminobutyric$ acid)-enriched sea tangle fermented in lactic acid (0.3%), and various amounts (0-10% gruel volume) of S. japonica powder. The pH, color, viscosity, spreadability, antioxidant activities, and sensory evaluation of the gruel were investigated. Spreadability and pH decreased, whereas viscosity and antioxidant activities increased, with increasing powder content. In addition, color lightness decreased significantly, whereas redness and yellowness increased. In sensory tests, color, aroma, and texture were rated highest for gruel with 5% powder. On the other hand, flavor and overall acceptability were considered optimal in gruel with 7% powder.

• The Korean Journal of Community Living Science
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• v.14 no.1
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• pp.87-96
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• 2003

This study was to examine the possibility of making use of the edible portion on the inner layer of chestnut, which is produced as wastes in the chestnut processing, into chestnut-noodle. To conduct this study, the chestnut powder, which is separated and collected from the inner layer, was used to examine the possibility of making chestnut-noodle. The structure of chestnut-noodle was observed by Scanning Electron Microscope (SEM) and the sensory quality was conducted to examine usability of the chestnut-noodle as compared to wheat flour noodle by Quantitative Descriptive Analysis (QDA). The ten sensory qualities : appearance, color, flavor, hardness, elasticity, cohesiveness, adhesiveness, chewiness, gumminess, and acceptability, were evaluated by 10 point Likert type scale with 10-50% of different ratio of chestnut powder. The chestnut-noodle made by 50% of the chestnut powder got higher points than 10 % of chestnut powder mix in color. However, the chestnut-noodle made by 50% of the chestnut powder got lower points than wheat flour noodle in flavor. Finally, there was no significant difference in hardness, elasticity, cohesiveness, adhesiveness, chewiness and gumminess between the chestnut-noodle made by 30% of the chestnut powder and wheat flour noodle.

• Korean Journal of Poultry Science
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• v.44 no.2
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• pp.135-141
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• 2017

This study was carried out to investigate physical properties of chicken emulsion sausage containing various amount of buckwheat powder. The fat content and apparent viscosity were observed gradually raised with level of buckwheat powder. The buckwheat powder contents influenced to improvement of emulsion stability. Increasing of buckwheat powder contents induced statistically decreasing of cooking loss and increasing of moisture contents of cooked sausage. However, hardness of cooked sausage was increased with level of buckwheat powder, it was due to gelatinization between protein and starch. In this study, it was suggested that addition of buckwheat powder contained higher dietary fiber changed physical properties of meat products.

• Journal of Powder Materials
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• v.17 no.2
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• pp.107-112
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• 2010

Carbon-nanotube-embedded bismuth telluride (CNT/$Bi_2Te_3$) matrix composites were fabricated by a powder metallurgy process. Composite powders, whereby 5 vol.% of functionalized CNTs were homogeneously mixed with $Bi_2Te_3$ alloying powders, were successfully synthesized by using high-energy ball milling process. The powders were consolidated into bulk CNT/$Bi_2Te_3$ composites by spark plasma sintering process at $350^{\circ}C$ for 10 min. The fabricated composites showed the uniform mixing and homogeneous dispersion of CNTs in the $Bi_2Te_3$ matrix. Seebeck coefficient of CNT/$Bi_2Te_3$ composites reveals that the composite has n-type semiconducting characteristics with values ranging $-55\;{\mu}V/K$ to $-95\;{\mu}V/K$ with increasing temperature. Furthermore, the significant reduction in thermal conductivity has been clearly observed in the composites. The results showed that CNT addition to thermoelectric materials could be useful method to obtain high thermoelectric performance.

• Food Science and Preservation
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• v.24 no.4
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• pp.505-509
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• 2017

Water vapor adsorption kinetics of vacuum-dried jujube powder were investigated in temperature and relative humidity ranges of 10 to $40^{\circ}C$ and 32 to 75%, respectively. Water vapor was initially adsorbed rapidly and then reached equilibrium condition slowly. Reaction rate constant for water vapor adsorption of vacuum-dried jujube powder increased with an increase in temperature. The temperature dependency of water activity followed the Clausius-Clapeyron equation. The net isosteric heat of sorption increased with an increase in water activity. Good straight lines were obtained with plotting of $1/(m-m_0)$ vs. 1/t. It was found that water vapor adsorption kinetics of vacuum-dried jujube powder was accurately described by a simple empirical model, and temperature dependency of the reaction rate constant followed the Arrhenius-type equation. The activation energy ranged from 50.90 to 56.00 kJ/mol depending on relative humidity. Arrhenius kinetic parameters ($E_a$ and $k_0$) for water vapor adsorption by vacuum-dried jujube powder showed an effect between the parameters with the isokinetic temperature of 302.51 K. The information on water vapor adsorption kinetics of vacuum-dried jujube powder can be used to establish the optimum condition for storage and processing of jujube.

• Journal of the Korean Society of Safety
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• v.27 no.6
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• pp.59-63
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• 2012

The use of dry chemical powder has been increased as it can be stored for a long period and sustain in stable condition compared to gas or liquid phase extinguishing agents. A new type of dry chemical powder using Zeolite was produced in the research. Chemical powder was adsorbed into Zeolite 13X, a porous material appearing negative catalytic effect, to create extinguishing powder obtaining core shell structure and measured physical properties and run a small scale fire extinguishment. SEM, XRD, TA analysis was also executed, and extinguishing characteristics were measured by fire extinguishing experiment on oil pool fire. The experiment showed that the average particle size of Zeolite 13X was equivalent, indicating about $3{\pm}1{\mu}m$ and thermal analysis result illustrated that Zeolite 13X showed exothermic reaction peaks at $900^{\circ}C$ due to solid-state transformation. Extinguishing characteristics on oil fire of $NaHCO_3$/Zeolite 13X and $NH_4H_2PO_4$/Zeolite were improved, influenced by adsorbed extinguishing powders on Zeolite 13X and Zeolite 13X that contains high phase transition temperature.

• Journal of the Korean Ceramic Society
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• v.30 no.4
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• pp.316-324
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• 1993

Three types of dispersed, coated and mechanically mixed SiC reinforced Al2O3 composite powders were used to investigate the effect of composite powder type on sintering characteristics and properties of Al2O3-SiC composites. Sinterability of coated type composite powders was superior to that of other composite powders when they were pressureless sintered at 1500~1$700^{\circ}C$ for 2h in Ar atmosphere. However, sinterabilities (>98% TD) of each type of composite powders were similar when they were hot pressed at 180$0^{\circ}C$ for 1h under 30MPa in N2 atmosphere. SiC powders were randomly distributed in the specimen prepared from dispersed type composite powders, whereas homogeneously distributed for coated type specimens. It was found that SiC powders inhibited the grain growth of Al2O3, and fracture toughness was increased by the increment of crack growth resistance due to residual stress by secondary SiC particles within Al2O3 grains.