• 한국세라믹학회지
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• 제37권4호
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• pp.308-313
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• 2000

Hydrous titanium oxide particles with anatase phase were prepared from 0.05 mol TiCl4 solution using NH4HCO3 as precipitant by the droopping precipitant method. The sequential change of pH is completed by a sudden and steep increase in a pH value of the range of 6~7 to which the concentration of adsorbed OH- and H+ ions on TiO2 surface is equal. Rutile phase started precipitating with anatase phase as an increase of reaction temperature above 6$0^{\circ}C$ in aqueous 0.05mol TiCl4 solution and its specific surface area was found to decrease from 452 $m^2$/g($25^{\circ}C$) to 164$m^2$/g(8$0^{\circ}C$). Specific surface area decreased rapidly when anatase powders precipitated at 4$0^{\circ}C$ were heat-treated at temperature higher 40$0^{\circ}C$. FT-IR result confirmed that it was due to the decrease of OH species within hydrous titanium oxides. The loss of ethanol after illumination of the powder heated at $600^{\circ}C$ and $700^{\circ}C$ for 4 h was 66 and 68.8%, respectively.

• 한국분무공학회지
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• 제22권3호
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• pp.109-115
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• 2017

The aim of this study is to investigate the effect of physical properties of fuels on spray characteristics in the gasoline direct injection system. Injection rate, spray visualization, and spray pattern experiments were performed to analyze the spray characteristics of ethanol, gasoline, and ethanol/gasoline blends. We measured injection rate of each fuel via the Bosch method. The spray visualization experiment was also carried out at atmospheric pressure using a high-speed camera. Finally, the average of drop surface area per unit volume was measured using the optical patternator. The experimental results from Bosch method showed that peak injection rate increased when the volume fraction of ethanol increased. In addition, higher viscosity of ethanol than that of gasoline leads to longer injection delay. At the initial injection region before reaching 0.8 ms, the spray tip penetration becomes longer as increasing the volume fraction of ethanol, but reversely shorter after 0.8 ms. It was found that ethanol makes spray angle become larger. The surface area per unit volume of the drop was decreased as the distance from the injection tip or the concentration of the gasoline increased.

• 한국세라믹학회지
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• 제46권6호
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• pp.583-586
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• 2009

The Tantalum nitride has attracted wide at attention as issues related to the toxicity of Cd-related materials. But in the titration process of Ta$Cl_5$ solution with $NH_4$OH, $NH_4$Cl, as a by product, was remained in the prepared Tantalum precursor. The tantalum precursor with $NH_4$Cl was nitrided by ammonolysis. The red color tone of $Ta_3N_5$ was reduced by the residual $NH_4$Cl reduce. Therefore, amorphous Tantalum precursor was prepared by filtering process with as hydrous ethanol to remove the $NH_4$Cl. In the case of using Tantalum precursor without $NH_4$Cl, we successfully synthesized the Tantalum nitride with good red color. The value of red color tone was improved from $a^*$=36.8 to $a^*$=53.0. The synthesized powder was characterized by XRD, SEM, the Nitrogen / Oxygen Determinator, TG-DTA, and the CIE $L^*a^*b^*$ colorimeter.

• 한국축산식품학회지
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• 제43권2호
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• pp.359-373
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• 2023

This study examined the α-glucosidase inhibitory, and apoptosis- and anti-muscular-related factors of goat meat extracts from forelegs, hind legs, loin, and ribs. The goat meat extracts were evaluated for their α-glucosidase inhibitory activity. The gene and protein expression levels of Bcl-2-associated X (bax), p53, and p21 were examined by reverse transcription polymerase chain reaction (RT-PCR) and immunoblotting in AGS and HT-29 cells. The expression levels of Atrogin-1 and MHC1b were examined by RT-PCR in C2C12 myoblasts, and the expression levels of Atrogin-1, muscle atrophy F-box (MAFbx), muscle RING-finger protein-1 (MuRF-1), and myosin heavy chain-7 were investigated by immunoblotting. α-Glucosidase inhibitory activity was higher in ethanol extract than in hydrous and hot water extracts. BAX and p53 expression levels were higher (p<0.05) in AGS cells treated with goat meat extract than those of cells treated with no goat meat extract. In HT-29 cells, the protein expression levels of BAX, p53, and p21 were higher (p<0.05) in the cells treated with goat meat extract than those of cells not treated with goat meat extract. In dexamethasone-treated C2C12 cells, goat meat extract treatment lower (p<0.05) the expression of Atrogin-1 and lower (p<0.05) the expression of MAFbx and MuRF-1. The results of the present study indicate that goat meat extracts have α-glucosidase inhibitory activity in vitro. In addition, apoptosis was induced in AGS cells and HT-29 cells treated with goat meat extract, and anti-muscular atrophy activity was also observed in C2C12 cells treated with goat meat extract.