• 한국전기전자재료학회논문지
• /
• 제29권7호
• /
• pp.414-423
• /
• 2016

In the present study, the $CuN_x-Cu-CuN_x$ layer the partial pressure ratio Cu metal of Ar and $N_2$ gas using a DC magnetron sputtering device, was generated by the In-situ method. $CuN_x$ layer was able to obtain a surface reflectance reduction effect from the advantages of the process and the external light. $CuN_x$ layer is gas partial pressure, DC the Power, the deposition time variable transmittance in response to the thickness and partial pressure ratio, the reflectance was measured. $Ar:N_2$ gas ratio 10:10(sccm), DC power 0.35 A, was derived Deposition time 90 sec optimum conditions. Thus, according to the optimal thickness and the composition ratio was derived surface reflectance of 20.75%. In addition, to derive the value of ${\Delta}$ Ra surface roughness of 0.467. It was derived $CuN_x$ band-gap energy of about 2.2 eV. Thus, to ensure a thickness and process conditions can be absorbed to maximize the light in a wavelength band in the visible light region. As a result, the implementation of the $12k{\Omega}$ base line resistance of using the Cu metal. This is, 5 inch Metal mesh TSP(L/S: $4/270{\mu}m$) is in the range of the reference operation.

• 한국전기전자재료학회논문지
• /
• 제29권10호
• /
• pp.601-607
• /
• 2016

Piezoelectric thick films of soft $Pb(Zr,Ti)O_3$ (PZT) based commercial material (S55) were fabricated using a conventional tape casting method. Ag-Pd electrodes were printed on the piezoelectric film at room temperature and all 5 layered films with a dimension of $12mm{\times}16mm$ were successfully laminated for a multi-layered piezoelectric ceramic actuator. The laminated specimens were co-fired at $1,100^{\circ}C$ for 1 h. A flat layered and dense microstructure was obtained for the $112{\mu}m$ thick piezoelectric actuator after sintering process. Thereafter, a prototype piezoelectric speaker was fabricated using the multi-layered piezoelectric ceramic actuator which can operate as a bimorph. Its SPL (sound pressure level) characteristic was also evaluated for speaker application. Frequency response revealed that the output SPL with a root mean square voltage of 10 V increased gradually to the highest peak of 87.5 dB for 1.5 kHz and exhibited a relatively stable behavior over the measured frequency range (${\leq}20kHz$) at a distance of 10 cm, implying that the fabricated piezoelectric speaker is potential for speaker applications.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권5호
• /
• pp.643-648
• /
• 2005

Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid, accurate method of evaluating some chemical constituents in cereal grains and forages. If samples could be analyzed without drying and grinding, then sample preparation time and costs may be reduced. This study was conducted to develop robust NIRS equations to predict fermentation quality of corn (Zea mays) silage and to select acceptable sample preparation methods for prediction of fermentation products in corn silage by NIRS. Prior to analysis, samples (n = 112) were either oven-dried and ground (OD), frozen in liquid nitrogen and ground (LN) and intact fresh (IF). Samples were scanned from 400 to 2,500 nm with an NIRS 6,500 monochromator. The samples were divided into calibration and validation sets. The spectral data were regressed on a range of dry matter (DM), pH and short chain organic acids using modified multivariate partial least squares (MPLS) analysis that used first and second order derivatives. All chemical analyses were conducted with fresh samples. From these treatments, calibration equations were developed successfully for concentrations of all constituents except butyric acid. Prediction accuracy, represented by standard error of prediction (SEP) and $R^2_{v}$ (variance accounted for in validation set), was slightly better with the LN treatment ($R^2$ 0.75-0.90) than for OD ($R^2$ 0.43-0.81) or IF ($R^2$ 0.62-0.79) treatments. Fermentation characteristics could be successfully predicted by NIRS analysis either with dry or fresh silage. Although statistical results for the OD and IF treatments were the lower than those of LN treatment, intact fresh (IF) treatment may be acceptable when processing is costly or when possible component alterations are expected.

• Asian-Australasian Journal of Animal Sciences
• /
• 제17권12호
• /
• pp.1641-1646
• /
• 2004

The objective of this study was to generate transgenic mice expressing human resistin gene by using the tetraploidembryonic stem (ES) cell complementation method. Human resistin gene was amplified from human fetal liver cDNA library by PCR, cloned into $pCR^{(R)}$ 2.1 $TOPO^{(R)}$ vector and constructed in pCMV-Tag4C vector. Mammalian expression plasmid containing human resistin was transfected into D3-GL ES cells by Lipofectamine 2,000, and then after 10-12 days of transfection, the human resistin-expressing cells were selected with G418. In order to produce tetraploid embryos, blastomeres of diploid embryos at the two-cell stage were fused with two times of electric pulse using 60 V 30 $\mu$sec (fusion rate: 2,114/2,256, 93.5%) and cultured up to the blastocyst stage (development rate: 1,862/2,114, 94.6%). The selected 15-20 ES cells were injected into tetraploid blastocysts, and then transferred into the uteri of E 2.5 d pseudopregnant recipient mice. To investigate the gestation progress, two E 19.5 mused fetuses were recovered by Cesarean section of which one fetus was confirmed to contain human resistin gene by genomic DNA-PCR. Therefore, our findings demonstrate that tetraploid-ES mouse technology can be considered as a useful tool to produce transgenic mice for the rapid analysis of gene function in vivo.

• Asian-Australasian Journal of Animal Sciences
• /
• 제27권3호
• /
• pp.330-341
• /
• 2014

Andropogon gayanus is an important grass due to its high biomass production, drought tolerance and favorable growth on low fertility acidic soils. Currently, there is little research on the impact of growth stage on the nutritional quality or the degree of $CH_4$ production that may arise from this forage during ruminal fermentation. The objectives of this study were to determine the effects of regrowth stage of A. gayanus on its chemical composition, in vitro production of gas and CH4, as well as in vitro dry matter (DM) digestibility when grown under tropical Brazilian conditions and conserved as hay or as silage. The nutritional value of A. gayanus grass declined with increasing maturity; however digestible DM yield linearly increased. After 112 d of regrowth, A. gayanus produced higher quality silage (higher lactate and lower pH and butyrate content) and higher DM yield. However, the low levels of crude protein at this time would make protein supplementation a necessity for proper rumen fermentation. No differences in $CH_4$ kinetic parameters were found with advancing maturity or preservation method (hay or silage).

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권5호
• /
• pp.2015-2020
• /
• 2012

Oleanolic acid (OA) is a naturally occurring triterpenoid in food materials and is a component of the leaves and roots of Olea europaea, Viscum album L., Aralia chinensis L. and more than 120 other plant species. There are several reports validating its antitumor activity against different cancer cells apart from its hepatoprotective activity. However, antitumor activity against skin cancer has not beed studied well thus far. Hence the present study of effects of OA against HaCaT (immortalized keratinocyte) cells - a cell-based epithelial model system for toxicity/ethnopharmacology-based studies - was conducted. Radical scavenging activity ($DPPH{\cdot}$) and FRAP were determined spectrophotometrically. Proliferation was assessed by XTT assay at 24, 48 and 72 hrs with exposure to various concentrations (12.5-200 ${\mu}M$) of OA. Apoptotic induction potential of OA was demonstrated using a cellular DNA fragmentation ELISA method. Morphological studies were also carried out to elucidate its antitumor potential. The results revealed that OA induces apoptosis by altering cellular morphology as well as DNA integrity in HaCaT cells in a dose-dependent manner, with comparatively low cytotoxicity. The moderate toxicity observed in HaCaT cells, with induction of apoptosis, possibly suggests greater involvement of programmed-cell death-mediated mechanisms. We conclude that OA has relatively low toxicity and has the potential to induce apoptosis in HaCaT cells and hence provides a substantial and sound scientific basis for further validation studies.

• Asian-Australasian Journal of Animal Sciences
• /
• 제5권2호
• /
• pp.295-301
• /
• 1992

Eight crop residues : 1, sorghum (Sorqhum bicolor) straw, 2, maize (Zea mays) straw, 3, cotton (Gossypium Sp.) straw, 4, sunflower (Helianthus Sp.) straw, 5, cotton (Gossypium Sp.) seed hulls, 6, groundnut (Archais hypogaea) hulls, 7, maize (Zea mays) cobs, 8, sugarcane (Saccharum officinarum) bagasse and two forest grasses 9, Heteropogan contortus dry grass and 10, Sehima nervosum dry grass were subjected to three physical processing 1, chopping (2-3 cm) 2, grinding (8 mm sieve) and 3, pelleting (10 mm die holes). The processed material was fed ad lib. Along with 250 g of concentrate mixture per head per day to 6 adult local goats and 16 adult Nellore rams in ten digestion experiments and finally assessed the nutritive value of the processed roughages by difference method. Grinding increased bulk density by 32.4 (cotton seed hulls, CSH) to 88.1% (Sehima dry grass) while pelleting of ground material increased bulk density by 53.9 (maize cobs) to 235.8% (maize straw). The average particle size ranged from $584.1/^U$ (sorghum straw) to $1467/^U$ (CSH). Modulus of uniformity ranged from 2:5:3 (sorghum straw) to 7:2:1 (CSH) while modulus of fineness ranged from 3.4 (sorghum straw) to 5.4 (CSH). Molasses absorbability was highest with cotton seed hulls and least with maize cobs. Pelleting increased DM intake of the residues except cotton seed hulls compared to grinding. Grinding of chopped material/unprocessed material increased DM intake on sorghum straw and cotton seed hulls. Sheep consumed more DM compared to goats on all the residues except sorghum and sunflower straws. Pelleting increased nutritive value of all the residues compared to grinding and chopping. However, no difference was observed in the nutritive value due to grinding and chopping. Goats performed better compared to sheep in utilizing the fibrous residues.

• 한국재료학회지
• /
• 제26권11호
• /
• pp.649-655
• /
• 2016

Ni nanoparticles (NPs)-graphitic carbon nanofiber (GCNF) composites were fabricated using an electrospinning method. The amounts of Ni precursor used as catalyst for the catalytic graphitization were controlled at 0, 2, 5, and 8 wt% to improve the photovoltaic performances of the nanoparticles and make them suitable for use as counter electrodes for dye-sensitized solar cells (DSSCs). As a result, Ni NPs-GCNF composites that were fabricated with 8 wt% Ni precursors showed a high circuit voltage (0.73 V), high photocurrent density ($14.26mA/cm^2$), and superb power-conversion efficiency (6.72%) when compared to those characteristics of other samples. These performance improvements can be attributed to the reduced charge transport resistance that results from the synergetic effect of the superior catalytic activity of Ni NPs and the efficient charge transfer due to the formation of GCNF with high electrical conductivity. Thus, Ni NPs-GCNF composites may be used as promising counter electrodes in DSSCs.

• 한국재료학회지
• /
• 제13권10호
• /
• pp.691-696
• /
• 2003

To improve the photocatalyticactivity of $TiO_2$-coated coal fly ash, tungsten hydroxide was doped by impregnation method and was oxidized by heat treatment in temperature ranges of $WO^{\circ}C$ for 2 hrs. The changes of crystal structure and crystal size of $TiO_2$and $WO_3$on coal fly ash were investigated by X-ray diffraction analysis. The crystal structure of titanium dioxide showed only anatase type and $TiO_2$-$WO_3$ compounds appeared in the heat treatment temperature ranges of $500∼600^{\circ}C$. By adding $V_3$in $TiO_2$coated on fly ash, the growth of crystal size of anatase was restrained and the anatase phase was stabilized in temperature ranges of TEX>$500∼<800^{\circ}C$. And $WO_3$acted as a trap site of electrons excited from anatase by irradiating UV. The maximum removal efficiency of NO gas for $TiO_2$/$WO_3$-coated coal fly ash was 84% and appeared when the ammonium tungstate of $1.3${\times}$10^{-3}$ M was doped and then heated at $600^{\circ}C$ for 2 hrs.

• 한국응용과학기술학회지
• /
• 제17권4호
• /
• pp.248-256
• /
• 2000

We investigated the property of formation of mono-vesicle(designated nano-some) with using of the combined co-emulsifiers and phospholipid. Nano-some was prepared with hydrogenated lecithin(HL) and diethanolamine cetyl phosphate(DEA-CP) by swelling reaction. Kojic acid and kojic dipalmitate could be made stabilization by nano-some system using microfluidizer(MF). Nano-some has a good affinity to skin by means of this system. The composition was compounded by 2% of hydrogenated lecithin (phosphatidyl choline contained with 75%, 0.5% of DEA-CP and 0.5% of diglyceryl dioleate (DGDO). To make nano-some, several conditions of MF have to be considered as follows. The optimum pH was 6.0. The pressure was 10,000psi and passage temperature was at $306^{\circ}C$. The nano-some base was passed to homogenize continually 3 times through MF. The Particle size distributions of the vesicles were with in $57{\sim}75.7nm$(mean 66nm) by measuring the Zetasizer-3000. Zeta potential of vesicles with 3 times passage through MF was -24.8mV. Formations for nano-some vesicle certificated photograph by scanning electric magnification (SEM). Stability of nano-some was very good for 6months. The turbidity was very good transparency compared nano-some with liposome. It was formed the mono vesicle in the opposite direction to be formed the multi-lamellar vesicle of liposome.