• Journal of the Korean institute of surface engineering
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• v.22 no.1
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• pp.43-51
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• 1989

The characteristion of composite electroless Nikel palting on the condition of adding 3kinds ceramic dispersives, Al2O3, Si3O4 and artificial diamond powder were studied. Decreasing solution temperature for composite plating was required to depress the spontaneous decomposition caused by dispersive including enlargement of reaction surface. The rate of composite plating was faster than that of general electroless-Nickel plating without dispersive. this increasing tendency of plating rate was remarkable for the active catalysis, like diamond powder.

• Carbon letters
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• v.16 no.4
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• pp.233-240
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• 2015

Electrochemical synthesis was employed to prepare a novel hydroxyapatite/graphene (HAP/Gr) composite powder suitable for medical applications as a hard tissue implant (scaffold). The synthesis was performed in a homogeneous dispersion containing Na₂H₂EDTA·2H₂O, NaH₂PO₄ and CaCl₂ with a Ca/EDTA/PO₄³⁻ concentration ratio of 0.25/0.25/0.15M, along with 0.01 wt% added graphene nanosheets, at a current density of 137 mA cm⁻² and pH value of 9.0. The field emission scanning electron microscopy and transmission electron microscopy observations of the composite HAP/Gr powder indicated that nanosized hydroxyapatite particles were uniformly placed in the graphene overlay. Raman spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction confirmed graphene incorporation in the HAP/Gr powder. The electrochemically prepared HAP/Gr composite powder exhibited slight antibacterial effect against the growth of the bacterial strain Staphylococcus aureus.

• Korean Journal of Metals and Materials
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• v.47 no.12
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• pp.866-872
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• 2009

The effects of magnetic powder thickness on electromagnetic wave absorption characteristics in Fe-6.5Si-0.9Cr (wt%) alloy flakes/polymer composite sheets available for quasi-microwave band have been investigated. The atomized FeSiCr powders were milled by using attritor for 12, 24, and 36 h, powder thickness changed from $40{\mu}m$ to $3{\mu}m$ upon 36 h milling. The composite sheet, including thinned magnetic flakes, exhibited higher power loss in the GHz frequency range as compared with the sheets having thick flakes. Moreover, both the complex permeability and the loss factor increased with the decrease in thickness of the alloy flakes. Therefore, the enhanced power loss property of the sheets containing thin alloy flakes was attributed to the flakes of high complex permeability, especially their imaginary part. Additionally, the complex permittivity was also increased with the reduction of flake thickness, and this behavior was considered to be helpful for improvement of the electromagnetic wave absorption characteristics in the composite sheets, including thin alloy flakes.

• Journal of the Korean Dietetic Association
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• v.16 no.4
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• pp.332-340
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• 2010

This study was conducted to develop an optimal composite recipe for nutritional cookies containing beet powder. Flour was substituted with whole wheat flour containing germinated brown rice powder. The sensory optimal composite recipe was determined by making cookies containing two levels of beet powder (A) or butter (B) according to Central Composite Design (CCD) and by conducting the sensory evaluation and instrumental analysis according to Response Surface Methodology (RSM). Using CCD, the results of physical measurement for ten conditions with two variables were obtained. The values of lightness (L), redness (a), and yellowness (b) were in the range of 36.65~49.03, 22.15~29.31, and 13.96~19.34, respectively. Lightness decreased significantly (P<0.001) and redness increased significantly (P<0.01) upon an increase in beet powder. The results of sensory evaluation showed very significant values in color (P<0.05), texture (P<0.05), flavor (P<0.01), taste (P<0.05), and overall quality (P<0.05), whereas those of the instrumental analysis showed significant values in lightness (P<0.001), redness (P<0.01), spread ratio (P<0.01), and hardness (P<0.05). As a result, the optimal sensory ratio of beet cookie was calculated for beet powder 7.75 g and butter 77.88 g.

• Journal of the Korean Dietetic Association
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• v.13 no.4
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• pp.368-378
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• 2007

This study was conducted to develop a optimal composite recipe of a functional muffin including Sweet pumpkin powder and to have the high preference to all age groups. Wheat flour was partically substituted by Sweet pumpkin powder to reduce the content of wheat flour. This study has produced the sensory optimal composite recipe by making muffin, respectively, with each 5 level of Sweet pumpkin powder($\X_1$), sugar($\X_2$), butter($\X_3$), by C.C.D(Central Composite Design) and conducting sensory evaluation and instrumental analysis by means of RSM(Response Surface Methodology). Sensory items showed very significant values in appearance, flavor, texture, overall quality(p<0.05), color(p<0.01), and instrumental analysis showed significant values in lightness, redness(p<0.01), yellowness(p<0.001), hardness, gumminess(p<0.05). Also sensory optimal ratio of Sweet pumpkin muffin was calculated as Sweet pumpkin powder 29.5g, sugar 72.6g, butter 79.3g, and it was revealed that the factors of influencing muffin aptitude were in order of Sweet pumpkin powder, butter, sugar.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2001.04a
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• pp.19-19
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• 2001

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2001.04a
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• pp.37-37
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• 2001

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2003.04a
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• pp.9-9
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• 2003

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.637.2-637.2
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• 2006

• Macromolecular Research
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• v.13 no.2
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• pp.120-127
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• 2005

Conventional poly(methyl methacrylate) (PMMA) bone cement has been widely used as an useful biopolymeric material to fix bone using artificial prostheses. However, many patients had to be reoperated, due to the poor mechanical and thermal properties of conventional PMMA bone cement, which are derived from the presence of unreacted MMA liquid, the shrinkage and bubble formation that occur during the curing process of the bone cement, and the high curing temperature ($above 100^{\circ}C$) which has to be used. In the present study, a composite PMMA bone cement was prepared by impregnating conventional PMMA bone cement with ultra high molecular weight polyethylene (UHMWPE) powder, in order to improve its mechanical and thermal properties. The UHMWPE powder has poor adhesion with other biopolymeric materials due to the inertness of the powder surface. Therefore, the surface of the UHMWPE powder was modified with two kinds of silane coupling agent containing amino groups (3-amino propyltriethoxysilane ($TSL 8331^{R}$) and N-(2-aminoethyl)-3-(amino propyltrimethoxysilane) ($TSL 8340^{R}$)), in order to improve its bonding strength with the conventional PMMA bone cement. The tensile strengths of the composite PMMA bone cements containing $3 wt\%$ of the UHMWPE powder surface-modified with various ratios of $TSL 8331^{R}$ and $TSL 8340^{R}$ were similar or a little higher than that of the conventional PMMA bone cement. However, no significant difference in the tensile strengths between the conventional PMMA bone cement and the composite PMMA bone cements could be found. However, the curing temperatures of the composite PMMA bone cements were significantly decreased.