• Asian-Australasian Journal of Animal Sciences
• /
• 제23권1호
• /
• pp.47-51
• /
• 2010

The objective of this study was to understand changes of plasma metabolites, hormones, and mRNA level of cytoplasmic phosphoenolpyruvate carboxykinase (PEPCK-C) in liver in spontaneous clinical ketosis; 10 clinically ketotic cows and 10 healthy cows were chosen from the same dairy farm. Eleven blood parameters and liver fat content were measured in all cows, and mRNA levels of PEPCK-C in liver were measured by semi-quantitative reverse transcription (RT) polymerase chain reaction (PCR). In ketotic cows, concentration of plasma glucose decreased (p<0.01), concentration of plasma nonesterified fatty acids (NEFA) and $\beta$-hydroxybutyric acid (BHBA) increased (p<0.01), liver fat content (18.8% wet weight) and activity of plasma aspartate aminotransferase (AST) increased (p<0.01), but concentration of plasma total bilirubin (TBIL), $\gamma$-glutamyl transpeptidase ($\gamma$-GT), and cholinesterase (CHE) increased (p>0.05). In addition, concentration of plasma insulin decreased (p<0.05), concentration of plasma glucagons decreased (p>0.05), and mRNA level of PEPCK-C in liver increased (p<0.05). It is concluded that the adaptative changes of metabolites, hormones, and mRNA level of PEPCK-C in ketotic cows were in favor of the enhancement of gluconeogenesis, the decrease of fat mobilization and the relief of ketosis, but these were still inadequate to relieve ketosis.

• 한국재료학회지
• /
• 제27권4호
• /
• pp.211-215
• /
• 2017

Reactive Ion Etching (RIE) and wet etching are employed in existing texturing processes to fabricate solar cells. Laser etching is used for particular purposes such as selective etching for grooves. However, such processes require a higher level of cost and longer processing time and those factors affect the unit cost of each process of fabricating solar cells. As a way to reduce the unit cost of this process of making solar cells, an atmospheric plasma source will be employed in this study for the texturing of crystalline silicon wafers. In this study, we produced the atmospheric plasma source and examined its basic properties. Then, using the prepared atmospheric plasma source, we performed the texturing process of crystalline silicon wafers. The results obtained from texturing processes employing the atmospheric plasma source and employing RIE were examined and compared with each other. The average reflectance of the specimens obtained from the atmospheric plasma texturing process was 7.88 %, while that of specimens obtained from the texturing process employing RIE was 8.04 %. Surface morphologies of textured wafers were examined and measured through Scanning Electron Microscopy (SEM) and similar shapes of reactive ion etched wafers were found. The Power Conversion Efficiencies (PCE) of the solar cells manufactured through each process were 16.97 % (atmospheric plasma texturing) and 16.29 % (RIE texturing).

• Bulletin of the Korean Chemical Society
• /
• 제35권12호
• /
• pp.3535-3541
• /
• 2014

Bisphenol A is considered as pollutant, because it is toxic and hazardous to living organisms even at very low concentrations. Biological oxidation used for removing this organic from waste water is not suitable and consequently application of catalytic wet oxidation has been considered as one of the best options for treating bisphenol A. We have developed Fe/SBA-15, Ni/SBA-15 and Fe-Ni/SBA-15 as heterogeneous catalysts using the advanced impregnation method for oxidation of bisphenol A in water. The catalysts were characterized with physico-chemical characterization methods such as, powder X-ray diffraction (PXRD), FT-IR measurements, N2 adsorption-desorption isotherm, thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis. This work illustrates activity of the catalysts for heterogeneous catalytic degradation reaction revealed with excellent conversion and recyclability. The degradation products identified were not persistent pollutants. GC-MS analysis identified the products: 2,4-hexadienedioic acid, 2,4-pentadienic acid and isopropanol or acetic acid. The leachability study indicated that the catalysts release very little metals to water. Therefore, the possibility of water contamination through metal leaching was almost negligible.

• 한국분말재료학회지
• /
• 제19권1호
• /
• pp.13-18
• /
• 2012

This study has been performed on the full density sintering of Fe nanopowder and the surface hardening by plasma ion nitriding. The Fe sintered part was fabricated by pressureless sintering of the Fe nanopowder at $700^{\circ}C$ in which the nanopowder agglomerates were controlled to have 0.5-5 ${\mu}m$ sized agglomerates with 150 nm Fe nanopowders. The green compact with 46% theoretical density(T.D.) showed a homogeneous microstructure with fine pores below 1 ${\mu}m$. After sintering, the powder compact underwent full densification process with above 98%T.D. and uniform nanoscale microstructure. This enhanced sintering is thought to be basically due to the homogeneous microstructure in the green compact in which the large pores are removed by wet-milling. Plasma ion nitriding of the sintered part resulted in the formation of ${\gamma}$'-$Fe_4N$ equilibrium phase with about 12 ${\mu}m$ thickness, leading to the surface hardening of the sintered Fe part. The surface hardness was remarkably increased from 176 $H_v$ for the matrix to 365 $H_v$.

• 한국미생물·생명공학회지
• /
• 제23권3호
• /
• pp.352-358
• /
• 1995

In this study, authors investigated the cadmium tolerance, the accumulation of cadmium, and the cellular distribution of accumlated cadmium in lactic acid bacteria under the anaerobic condition. Lactic acid bacteria grew fairly well in modified EG medium containing 10 ppm of cadmium but could hardly grow at 50 ppm of cadmium. Tolerance to cadmium of genus Lactobacillus was greater than that of genus Streptococcus, and Lactobacillus acidophilus showed the higest cadmium tolerance amomg the bacteria tested. The capacity of cadmium accumlation (9.304-12.428 mg/g wet cell) of lactic acid bacteria was higher than that (6.775 mg/g wet cell) of Escherichia coli. Lactobacillus casei of them took up the largest amount of cadmium. The cadmium elimination amount (28.46-29.25%) of lactic acid bacteria from modified EG medium containing cadmium were also higher than that (14.43%) of Escherichia coli. Accumulated cadmium in Lactobacillus acidophilus was distributed by 42.41% at cell wall, 28.97% at cytoplasm, and 28.62% at plasma membrane, respectively.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
• /
• pp.601-604
• /
• 2006

We have developed ZnO TFT array using conventional photolithography and wet etching processes. Transparent 20 nm of ultra thin ZnO film deposited by means of plasma enhanced atomic layer deposition at $100^{\circ}C$ was used for the active channel. The ZnO TFT has a mobility of $0.59cm^2/V.s$, a threshold voltage of 7.2V, sub-threshold swing of 0.64V/dec., and an on/off ratio of $10^8$.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
• /
• pp.359-361
• /
• 2003

Nano-porous alumina was investigated as a protecting layer in an AC Plasma Display Panel. A 2 ${\mu}m$ thick nano-porous $Al_2O_3$ layer inserted with MgO was formed on the dielectric layer instead of the conventional 500 nm-thick MgO thin film. Both nano-porous $Al_2O_3$layer and inserted MgO were prepared by wet process. The luminance and luminous efficiency of 3-inch test panel adopting nano-porous $Al_2O_3$ was higher than that of the conventional PDP.

• 한국의류학회지
• /
• 제28권1호
• /
• pp.165-171
• /
• 2004

The analytical method of toxic heavy metals in disposable diapers was developed. Disposable diapers obtained from Korea, Japan, America and German were determinated and quantified. Sample treatment (Total Digestion) was wet chemical acid digestion for extraction of nine hazardous inorganic elements (Sb, As, Pb, Cd, Cr, Co, Cu, Ni, Hg) in disposable diapers. Inductively Coupled Plasma Mass Spectrometer (ICP-MS) and Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) have been used for analyzing nine hazardous inorganic elements. The results were as follows : The concentration of extractable Sb which was treated for 3 hours with artificial urine and disposable diapers was higher than those of 6 hours and 24 hours. The concentration of extractable Cr was same as Sb. On the other hands, the behavior of Cu and Ni were different from Sb and Cr. Concentrations of extractable Cu and Ni increased as increasing the reaction time between artificial urine and disposable diapers.

• 대한기계학회논문집
• /
• 제17권12호
• /
• pp.3083-3093
• /
• 1993

Friction and wear at ceramic coated surfaces of aluminum alloy were experimentally studied using a Ring-on-Block wear test machine. Ceramic materials coated on aluminum alloy surfaces were WC, CrC, $Al_{2}O_{3}$ by a plasma spray; and $Al_{2}O_{3}$,$Al_{2}SiO_{5}$, $Na_{2}B_{4}O_{7}$,$Na_{4}P_{2}O_{7}$, and $Al_{2}O_{3}-ZrO_{2}$ composite coating by an Anodic Spark Depositon. They were tested under the sliding wet contact and compared with aluminum alloys and steels. Test results showed that ceramic coated surfaces, in general, have better anti-wear property than those of aluminum alloys due to increase in the surface hardness ; however, they also showed higher coefficients of friction and changes in wear mechanisms, resulting in brittle fractures.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 하계학술대회 논문집
• /
• pp.824-827
• /
• 2000

Fabrication of InP-based photonic devices by dry etch Process is important for clear formation of waveguide mesa structure. We have developed more efficient etch process of the inductively coupled plasma (ICP) with low damages and less polymeric deposits for the InP-based photonic devices than the reactive ion etching (RIE) technique. We report the tendency of etch rate variation by the process parameters of the RF power, pressure, gas flow rate, and the gas mixing ratio. The surface roughness of InP-based waveguide structure was more improved by the light wet etching in the mixed solution of H$_2$SO$_4$:H$_2$O (1:1)