• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.7
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• pp.929-933
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• 2010

Four-point bending tests were performed to investigate the interfacial adhesion of Cu-Cu bonding fabricated by thermo-compression process for three dimensional packaging. A pair of Cu-coated Si wafers was bonded under a pressure of 15 kN at $350^{\circ}C$ for 1 h, followed by post annealing at $350^{\circ}C$ for 1 h. The bonded wafers were diced into $30\;mm\;{\times}\;3\;mm$ pieces for the test. Each specimen had a $400-{\mu}m$-deep notch along the center. An optical inspection module was installed in the testing apparatus to observe crack initiation at the notch and crack propagation over the weak interface. The tests were performed under a fixed loading speed, and the corresponding load was measured. The measured interfacial adhesion energy of the Cu-to-Cu bonding was $9.75\;J/m^2$, and the delaminated interfaces were analyzed after the test. The surface analysis shows that the delamination occurred in the interface between $SiO_2$ and Ti.

• Journal of the Korean Chemical Society
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• v.54 no.6
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• pp.737-743
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• 2010

Coupling of 5-amino-1,3-diaryl-pyrazoles 1a-c with diazonium salts of different aryl amines gave a series of novel 1,3-diaryl-5-amino-4-arylazopyrazoles 3a-l. Such compounds could be also obtained by reaction of 5-amino-1,3-diaryl-4-nitroso- 1H-pyrazoles 2a-c with different aryl amines in alkaline medium. Oxidation of azo derivatives 3a-l with cupric acetate, in dimethyl formamide and stream of air, gave 2,4,6-triaryl-2,4-dihydropyrazolo [4,3-d]-1,2,3-triazoles 4a-l. and the fluorescence properties of the cyclic triazoles were studied. Diazotization of 5-amino-1,3-diaryl-1H-pyrazoles 1a-c by sodium nitrite in ortho-phosphoric acid followed by coupling with some aryl amines gave o-aminoazo compounds 5a-f. Cyclisation of compounds 5a-f in pyridine and cupric acetate gave the corresponding triazoles 6a-f. The coupling of compounds 6a-f with different aryl diazonium salts gave compounds 7a-j. The synthesized dyes were applied to polyesters as disperse dyes and the fastness properties were evaluated.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.10
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• pp.1308-1318
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• 2010

The purpose of this study was to evaluate the effect of replacing soybean meal with treated castor meal with (CMT) or without lime (CMNT) on the nutrient intake, performance, carcass characteristics, and yield of commercial cuts of beef cattle from a feedlot. Thirty male, castrated, crossbreed zebu cattle were used in the study, with an average initial weight of $360{\pm}30.27\;kg$. Five animals were used as a control group and were slaughtered at the beginning of the experiment; the remaining animals (n = 25) were distributed in random blocks (repetitions), with body weight as the criterion for block assignment. The animals were fed a diet containing 65% corn silage and 35% of concentrate on dry matter (DM) basis. Five diets consisted of four levels of soybean meal (SM) substituted with CMT (0, 33, 67 and 100%) on a DM basis and a diet with 100% of SM replaced with CMNT. At the end of the experiment, all animals were slaughtered, and their gastrointestinal tracts were emptied to determine their empty body weights (EBW). No significant effects were observed (p>0.05) for the substitution of soybean meal with CMT on intake of dietary nutrients, the average daily body weight gain (ADG) or EBW gain (EBWG). In spite of greater (p<0.05) ricin intake for the diet containing CMNT (3.06 mg/kg BW) compared to the CMT diet (0.10 mg/kg BW/d), there were no effects (p>0.05) on intake of dietary nutrients, ADG or EBWG. The average intake of DM and the ADG were 10,664.63 and 1,353.04 g/d, respectively. Regarding carcass characteristics, only carcass yield in relation to body weight was linearly reduced (p<0.05) upon substitution of SM by CMT. There was no effect (p>0.05) of the substitution of SM by CMT or CMNT on the yield of carcass basic cuts. CMT prices that are higher than 85% of the SM price do not economically justify the use of CMT. For CMT prices between 20 and 80% of the SM price, the optimal level was 67% substitution, while for prices below 15% of the SM price, the optimal level was 100% substitution with CMT. It can be concluded that treated castor meal with 6% lime can totally replace soybean meal in beef cattle diets.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.12
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• pp.1632-1638
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• 2010

Two experiments with growing pigs were conducted to investigate the effects of two distinct multienzyme preparations on nutrient digestibility, growth performance and blood profiles. In Exp. 1, a total of 96 pigs ($29.7{\pm}0.69\;kg$) were utilized in a 42-day performance and digestibility trial using four dietary treatments: CON (control diet), ENDO (control+0.10% Endopower), NSPase1 (control+0.10% NSPase) and NSPase2 (control+0.20% NSPase). Endopower was a commercial multienzyme preparation which contained ${\alpha}$-galactosidase, galactomannase, xylanase and ${\beta}$-glucanase. NSPase mainly contained ${\alpha}$-1,6-${\beta}$-galactosidase, ${\beta}$-1,4-mannanase and ${\beta}$-1,4-mannosidase. There were six replication pens per treatment with four pigs per pen. Pigs fed NSPase1 diet had a higher ADG (p<0.05) and G:F (p<0.05) than those fed the control diet. There were no significant differences in growth performance among the multienzyme treatments (p>0.05). Compared with CON, apparent digestibility of DM was increased (p<0.05) by ENDO treatment. N digestibility was improved (p<0.05) in response to multienzyme treatments during the experimental period. Blood urea nitrogen (BUN) was higher (p<0.05) in ENDO treatment than in CON and NSPase1 treatments at the end of the experiment, while the glucose level improved (p<0.05) due to ENDO and NSPase2 treatments. In Exp. 2, four ileal-cannulated, growing barrows ($20.17{\pm}1.31\;kg$) were housed in individual metabolism crates and randomly assigned to 1of 4 treatments (same as Exp. 1) within a $4{\times}4$ Latin square design. Enzyme supplementations improved the majority of apparent ileal amino acid digestibilities (p<0.05). It is concluded that the supplementation of NSPase1 improved growth performance as well as N digestibility and partially improved apparent ileal amino acid digestibility in growing pigs fed a diet based on corn and soybean meal.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.2
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• pp.246-252
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• 2010

In order to improve the availability of phytase and probiotics together, a phytase gene from Aspergillus ficuum has been expressed in Lactobacillus. In this study, the transformed Lactobacillus with phytase gene was fed to pigs to determine its effect on pig production, feed conversion and gut microbes. Forty eight, 60-day-old, castrated pigs (Duroc${\times}$Landrace${\times}$Pietrain) were assigned to 6 groups, 8 pigs for each group. Group 1 was the control, group 2 was added with chlortetracycline (500 mg/kg), group 3 was added with the transformed Lactobacillus (500 mg/kg) with 20% (w/w) of calcium monohydrogen phosphate (CMP, $CaHPO_{4}$) removed, group 4 was added with the natural Lactobacillus (500 mg/kg) with 20% (w/w) of CMP removed, group 5 was added with the transformed Lactobacillus (500 mg/kg) with 40% (w/w) of CMP removed, group 6 was added with phytase (500 mg/kg) with 40% (w/w) of CMP removed. The results showed: i) the average daily gain (ADG) was improved in groups 2, 3 and 4 (p<0.05); ii) the diarrhea rates in the groups added with Lactobacillus were lower than in the other groups (p<0.05), in which the transformed Lactobacillus had more effect on reducing digestive disease; iii) the transformed Lactobacillus was most effective in improving the digestibilities of crude protein (CP), calcium (Ca), phosphorus (P), compared with the other groups (p<0.05); iv) Lactobacillus could increase lactic acid bacterium number and ammonia concentrations, and decrease pH values and E. coli number in pig feces (p<0.05); v) the phytase activity in the feces of pigs fed with the transformed Lactobacillus was 133.32 U/g, which was higher than in group 4 (9.58 U/g, p<0.05), and was almost the same as group 6 (135.94 U/g); vi) the transformed Lactobacillus could increase serum concentrations of IgA, triglyceride, and glutamic oxaloacetic transaminase activity (p<0.05), and had no significant effect on other serum indexes (p>0.05).

• Journal of the Korean Vacuum Society
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• v.19 no.1
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• pp.52-57
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• 2010

$BiFeO_3/Pb(Zr_{0.52}Ti_{0.48})O_3$(BFO/PZT) multilayer thin films have been prepared on a Pt/Ti/$SiO_2$/Si(100) substrate by chemical solution deposition. BFO single layer, BFO/PZT bilayer and multilayer thin films were studied for comparison. X-ray diffraction analysis showed that the crystal structure of all films was multi-orientated perovskite phase without amorphous and impurity phase. The leakage current density at 500 kV/cm was reduced by approximately four and five orders of magnitude by bilayer and multilayer structure films, compared with BFO single layer film. The low leakage current density leads to saturated P-E hysteresis loops of bilayer and multilayer films. In BFO/PZT multlayer film, saturated remanent polarization of $44.3{\mu}C/cm^2$ was obtained at room temperature at 1 kHz with the coercive field($2E_c$) of 681.4 kV/cm.

• Journal of the Korean Vacuum Society
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• v.19 no.1
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• pp.22-27
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• 2010

To improve surface wettability, each sample was treated by atmospheric pressure plasma (APP) using dielectric barrier discharge (DBD) system. Argon and oxygen gases were used for treatment gas to modify the $TiO_2$ surface by APP with RF power range from 50 to 200 W. Water contact angle was decreased from $20^{\circ}$ to $10^{\circ}$ with argon only. However, water contact angle was decreased from $20^{\circ}$ to < $1^{\circ}$ with mixture of argon and oxygen. Water contact angle with $O_2$ plasma was lower than water contact angle with Ar plasma at the same RF power. It seems to be increasing the polar force of $TiO_2$ surface. Also, analysis result of X-ray photoelectron spectra (XPS) shows the increase of intensity of O1s shoulder peak, resulting in increasing of surface wettability by APP. Moreover, each water contact angle increased according to increase past time. However, contact angle increase with plasma treatment was lower than without plasma treatment. Additionally, the efficiency of $TiO_2$ photocatalyst was improved by plasma surface-treatment through the degradation experiment of phenol.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.5
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• pp.491-498
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• 2010

Humidification of PEM fuel cells is necessary for enhancing their performance and lifetime. In this study, a humidification system was designed and tested; the system includes an air-supply tube (inner diameter: 75 mm) through which a nozzle can be directly inserted and a cyclonic separator for the removal of water droplets. Three types of nozzles were employed to study the influence of injection pressure, air flow rate, and spray direction on the humidification performance. To evaluate the humidification performance, the concept of humidification efficiency was defined. In the absence of an external heat source, latent heat for evaporation will be supplied by the own enthalpies of water and air. Thus, the amount of water sprayed from the nozzle is the most critical factor affecting the humidification efficiency. Water droplets were efficiently removed by a cyclonic separator, but re-entrainment occurred at high air flow rates. The absolute humidity and humidification efficiency were $21.29\;kJ/kg_{da}$ and 86.57%, respectively, under the following conditions: nozzle type PJ24; spray direction angle $90^{\circ}$; injection pressure 1200 kPa; air flow rate 6000 Nlpm.

• Korean Journal of Materials Research
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• v.20 no.10
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• pp.501-507
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• 2010

Changes in surface morphology and roughness of dc sputtered ZnO:Al/Ag back reflectors by varying the deposition temperature and their influence on the performance of flexible silicon thin film solar cells were systematically investigated. By increasing the deposition temperature from $25^{\circ}C$ to $500^{\circ}C$, the grain size of Ag thin films increased from 100 nm to 1000 nm and the grain size distribution became irregular, which resulted in an increment of surface roughness from 6.6 nm to 46.6 nm. Even after the 100 nm thick ZnO:Al film deposition, the surface morphology and roughness of the ZnO:Al/Ag double structured back reflectors were the same as those of the Ag layers, meaning that the ZnO:Al films were deposited conformally on the Ag films without unnecessary changes in the surfacefeatures. The diffused reflectance of the back reflectors improved significantly with the increasing grain size and surface roughness of the Ag films, and in particular, an enhanced diffused reflectance in the long wavelength over 800 nm was observed in the Ag back reflectors deposited at $500^{\circ}C$, which had an irregular grain size distribution of 200-1000 nm and large surface roughness. The improved light scattering properties on the rough ZnO:Al/Ag back reflector surfaces led to an increase of light trapping in the solar cells, and this resulted in a noticeable improvement in the $J_{sc}$ values from 9.94 mA/$cm^2$ for the flat Ag back reflector at $25^{\circ}C$ to 13.36 mA/$cm^2$ for the rough one at $500^{\circ}C$. A conversion efficiency of 7.60% ($V_{oc}$ = 0.93, $J_{sc}$ = 13.36 mA/$cm^2$, FF = 61%) was achieved in the flexible silicon thin film solar cells at this moment.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.1
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• pp.58-63
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• 2010

The glass-ceramics made from the mixture of coal bottom ash, produced from a thermal power plant mixed with $Na_2O$ and $Li_2O$ was fabricated and their crystallization behavior was studied using a non-isothermal analyzing method. The temperature for 50% crystallization was higher than the exothermic peak temperature $T_p$ at DTA curve and the quickest crystallization temperature was much the same as $T_p$ as identified from the relationships of crystallized fraction and crystallization rate with temperature. By using Kissinger equation describing a crystallization behavior, the activation energy (262 kJ/mol), the Avrami constant (1.7) and the frequency ($5.7{\times}10^{16}/s$) for crystallization were calculated from which the nepheline crystal could be expected as showing an 1~2-dimensional surface crystallization behavior mainly with some bulk crystallization tendency at the same time. The actual observation of microstructure using SEM showed the considerable amount of surface crystals of dendrite and the bulk crystals with low fraction, so the prediction by the Kissinger equation was in accord with the crystallization behavior of glass-ceramics fabricated in this study.