• Korean Journal of Materials Research
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• v.20 no.12
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• pp.669-675
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• 2010

One of the greatest challenges for our society is providing powerful electrochemical energy conversion and storage devices. Rechargeable lithium-ion batteries and fuel cells are among the most promising candidates in terms of energy and power density. As the starting material, $TiCl_4{\cdot}YCl_3$ solution and dispersing agent (HCP) were mixed and synthesized using ammonia as the precipitation agent, in order to prepare the nano size Y doped spherical $TiO_2$ precursor. Then, the $Li_4Ti_5O_{12}$ was synthesized using solid state reaction method through the stoichiometric mixture of Y doped spherical $TiO_2$ precursor and LiOH. The Ti mole increased the concentration of the spherical particle size due to the addition of HPC with a similar particle size distribution in a well in which $Li_4Ti_5O_{12}$ spherical particles could be obtained. The optimal synthesis conditions and the molar ratio of the Ti 0.05 mol reaction at $50^{\circ}C$ for 30 minutes and at $850^{\circ}C$ for 6 hours heat treatment time were optimized. $Li_4Ti_5O_{12}$ was prepared by the above conditions as a working electrode after generating the Coin cell; then, electrochemical properties were evaluated when the voltage range of 1.5V was flat, the initial capacity was 141 mAh/g, and cycle retention rate was 86%; also, redox reactions between 1.5 and 1.7V, which arose from the insertion and deintercalation of 0.005 mole of Y doping is not a case of doping because the C-rate characteristics were significantly better.

• Clean Technology
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• v.14 no.3
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• pp.204-210
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• 2008

A series of $V_{2}O_{5}-TiO_2$ xerogel catalysts were prepared by nonhydrolytic sol-gel method and analysed by various characterization techniques. These catalysts showed much higher surface areas and total pore volumes than conventional V$V_{2}O_{5}-TiO_2$ xerogel and impregnated $V_{2}O_{5}/TiO_2$ catalysts. It was found that the textural property of $V_{2}O_{5}-TiO_2$ material varies with the method and conditions of synthesis. Surface vanadates and $TiO_2$ anatase phase are the crucial factors to obtain high catalytic activities. The selective oxidation of hydrogen sulfide in the presence of excess water and ammonia was studied over these catalysts. Xerogel catalysts prepared by non-hydrolytic sol-gel method showed very high conversion of $H_{2}S$ without harmful emission of $SO_2$. The highest catalytic activity shown by these $V_{2}O_{5}-TiO_2$ catalysts may be due to their high surface area and good dispersion of vanadia species in the titania matrix.

• Journal of Animal Environmental Science
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• v.9 no.1
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• pp.27-34
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• 2003

This experiment was carried out to investigate the effect of dietary supplementation of fermented microbial complex(Eco-Farm$^{(R)}$) on performance of finishing pigs and indoor air quality in finishing building. A total 135 crossbred [(Landrace ${\times}$ Yorkshire) ${\times}$ Duroc] pigs were randomly arranged into nine groups and assigned to three treatments. Pigs were fed a basal diet supplemented with 0, 0.5 and 1% level of fermented microbial complex(Eco-Farm$^{(R)}$) until the market weight for 40 days of the experimental period. Average daily feed intake and feed conversion ratio were significantly improved (p<0.05) with dietary supplementation of 0.5% fermented microbial complex (Eco-Farm$^{(R)}$): however, average daily gain was not affected by dietary supplementation of fermented microbial complex(Eco-Farm$^{(R)}$). Indoor ammonia and hydrogen sulfide concentrations in the finishing building were significantly(p<0.05) decreased by dietary supplementation of fermented microbial complex(Eco-Farm$^{(R)}$) compared with those of control, however, indoor carbon dioxide concentration was not affected by dietary supplementation of fermented microbial complex(Eco-Farm$^{(R)}$). In conclusion, the results obtained from this experiment suggest that the dietary supplementation of fermented microbial complex(Eco-Farm$^{(R)}$) for finishing pigs improved performance and indoor air quality in the finishing building.hing building.

• Korean Chemical Engineering Research
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• v.57 no.5
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• pp.714-722
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• 2019

Catalysts were prepared by using incipient wetness impregnation method with 17 wt% Ni on a support ($SiO_2-Y_2O_3$, $Al_2O_3$, $SiO_2-ZrO_2$, $SiO_2$, $TiO_2$, MgO) and the catalytic activity in the reductive amination of ethanol with ammonia in the presence of hydrogen was compared and evaluated. The catalysts used before and after the reaction were characterized using X-ray diffraction, nitrogen adsorption, ethanol-temperature programmed desorption (EtOH-TPD), isopropanol-temperature programmed desorption (IPA-TPD), and hydrogen chemisorption etc. In the case of preparing $ZrO_2$ and $Y_2O_3$ supports, the small amount of Si dissolution from the Pyrex reactor surface provoked the formation of mixed oxides $SiO_2-ZrO_2$ and $SiO_2-Y_2O_3$. Among the catalysts used, $Ni/SiO_2-Y_2O_3$ catalyst showed the best activity, and this good activity was closely related to the highest nickel dispersion, and low desorption temperature in EtOH-TPD and IPA-TPD. The low catalytic activity on Ni/MgO catalysts showed low activity due to the formation of NiO-MgO solid-solutions. In the case of $Ni/TiO_2$, the reactivity was low due to the low nickel metal phase due to strong metal-support interaction. In the case of using a support as $SiO_2-Y_2O_3$, $Al_2O_3$, $SiO_2-ZrO_2$, and $SiO_2$, the selectivities of ethylamines and acetonitrile were not significantly different at similar ethanol conversion.

• Korean Journal of Materials Research
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• v.32 no.11
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• pp.496-507
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• 2022

For the selective catalytic reduction of NOx with ammonia (NH₃-SCR), a V₂O₅WO₃/TiO₂ (VW/nTi) catalyst was prepared using V₂O₅ and WO₃ on a nanodispersed TiO₂ (nTi) support by simple impregnation process. The nTi support was dispersed for 0~3 hrs under controlled bead-milling in ethanol. The average particle size (D₅₀) of nTi was reduced from 582 nm to 93 nm depending on the milling time. The NOx activity of these catalysts with maximum temperature shift was influenced by the dispersion of the TiO₂. For the V_0.5W₂/nTi-0h catalyst, prepared with 582 nm nTi-0h before milling, the decomposition temperature with over 94 % NOx conversion had a narrow temperature window, within the range of 365-391 ℃. Similarly, the V_0.5W₂/nTi-2h catalyst, prepared with 107 nm nTi-2h bead-milled for 2hrs, showed a broad temperature window in the range of 358~450 ℃. However, the V_0.5W₂/Ti catalyst (D₅₀ = 2.4 ㎛, aqueous, without milling) was observed at 325-385 ℃. Our results could pave the way for the production of effective NOx decomposition catalysts with a higher temperature range. This approach is also better at facilitating the dispersion on the support material. NH₃-TPD, H₂-TPR, FT-IR, and XPS were used to investigate the role of nTi in the DeNOx catalyst.

• Journal of Animal Science and Technology
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• v.66 no.2
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• pp.326-339
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• 2024

This study was conducted to investigate the effects of protease supplementation and different nutrient density of diets in growing-finishing pigs. A total of one hundred-eight crossbred growing pigs ([Landrace × Yorkshire] × Duroc) with an initial body weight (BW; 18.74 ± 3.46 kg) were used for 15 weeks. Pigs were randomly assigned to six dietary treatments with 6 replicates of 3 pigs per pen in a 3 × 2 factorial through the following arrangement: Three groups of protease (1, Basal diets; 2, Protease A: 125 mg/kg protease derived from Streptomyces sps; 3, Protease B: 100 mg/kg protease derived from Bacillus licheniformis) at two different nutrient density diets (1, Basal requirement; 2, 0.94%-0.98% higher than requirement in dietary protein and 50 kcal/kg in energy). High nutrient (HN) diets showed higher average daily gain (ADG) (p < 0.05) and apparent total tract digestibility (ATTD) of crude protein (CP) (p < .0001) compared to basal nutrient (BN) diets during growing periods. Supplementation of protease showed higher BW (p < 0.05) and ADG (p < 0.05) compared to non-supplementation of protease during growing periods. Also, supplementation of protease showed higher ATTD of CP (p < 0.01), ATTD of gross energy (p < 0.05) and decreased blood urea nitrogen (BUN) level (p = 0.001) compared to non-supplementation of protease during finishing periods. Pigs which fed the protease showed decreased ammonia (NH₃) emissions (p < 0.05) during experiment periods and decreased hydrogen sulfide (H₂S) emissions (p < 0.01) during finishing periods. Interactions between nutrient density and protease were observed, which decreased the feed conversion ratio (p < 0.05) in HN diets without protease compared to BN diets without protease during weeks 4 to 6. Also, interaction between nutrient density and protease was observed, which resulted in improved ATTD of CP (p < 0.01) in response to PTA supplementation with HN diets during the finishing period. In conclusion, supplementation of protease reduces NH₃ in feces and BUN in whole blood by increasing the digestibility of CP and improves growth performance. Also, diets with high nutrient density improved growth performance and nutrient digestibility in growing periods.

• Journal of Animal Science and Technology
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• v.66 no.4
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• pp.763-780
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• 2024

This study was conducted to supplement single and complex probiotics to investigate the effect on growing-finishing pigs and compost. In experiment 1, the 64 crossbred ([Landrace × Yorkshire] × Duroc) pigs with an initial body weight of 18.75 ± 0.33 kg and a birth of 63 days were assigned to a completely randomized four treatment groups based on the initial body weight (4 pigs in a pen with 4 replicate pens for each treatment). For 13 weeks, the dietary treatments were provided: 1) Control (CON; basal diet), 2) T1 (CON + 0.2% Bacillus subtilis), 3) T2 (CON + 0.2% Saccharomyces cerevisiae), 4) T3 (CON + 0.2% Bacillus subtilis + 0.2% Saccharomyces cerevisiae). In experiment 2, the pig manure was obtained from Chungbuk National University (Cheongju, Korea) swine farm. For 12 weeks, the supplementary treatments were provided: 1) CON, non-additive compost; 2) T1, spray Bacillus subtilis 10 g per 3.306 m²; 3) T2, spray Bacillus subtilis 40 g per 3.306 m²; 4) T3, spray Saccharomyces cerevisiae 10 g per 3.306 m²; 5) T4: spray Saccharomyces cerevisiae 40 g per 3.306 m²; 6) T5, spray Bacillus subtilis 5 g + Saccharomyces cerevisiae 5 g per 3.306 m²; 7) T6, spray Saccharomyces subtilis 20 g + S. cerevisiae 20 g per 3.306 m² and there were 6 replicates each treatment. In experiment 1, During the overall experimental period, T3 showed significantly improved (p < 0.05) feed conversion ratio and average daily gain compared to other groups. In average maturity score, T3 showed significantly higher (p < 0.05) than other groups. Supplementing complex probiotics group improved (p < 0.05) H2S emissions and fecal microflora compared to the non-supplementing group. In experiment 2, additive probiotics groups had no effect (p > 0.05) on moisture content than the non-additive group at 9 and 12 weeks. T6 showed a significantly improved (p < 0.05) average maturity score at all periods and ammonia emissions at 1 week and 4 weeks compared to other groups. In summary, supplementation complex probiotics induced positive effects on both pigs and compost.

• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.688-693
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• 2014

For investigating NO reduction activity of an catalytic filter, the catalytic performance was measured under the presence of $SO_2$ and $H_2O$, respectively or simultaneously in the simulation gas composed of NO, $NH_3$, and air. The catalytic filter was prepared by coating $V_2O_5-WO_3/TiO_2$ catalyst on the pore surface of SiC filter element of which the superior performance for the particulate removal was well known. At the temperature below $260^{\circ}C$, the catalytic activities were enormously decreased under the presence of $SO_2$ and $H_2O$, respectively or simultaneously, compared with those under the cases of the absence of $SO_2$ and $H_2O$. However, the presence of $SO_2$ promoted the performance of the catalytic filter above $320^{\circ}C$ with showing the NO conversion better than 99.8% for the NO inlet concentration of 500 ppm and at the face velocity of 2 cm/s. In particular, the presence of water showed high NO conversion higher than 99% up to high temperature of $380^{\circ}C$. This effect of water was explained by the reason that it retarded the ammonia oxidation which is the main step into the formation of $N_2O$. The initial NO reduction activity of the catalytic filter maintained for the duration of 100 hours in the presence of $SO_2$ and $H_2O$. Therefore, it was concluded that the catalytic filter was promisingly useful for the industrial NOx reduction catalyst in order to treat the particulate and NO simultaneously.

• Korean Journal of Poultry Science
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• v.29 no.3
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• pp.205-211
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• 2002

A feeding trial was conducted to study the effects of a live yeast, Pichia farinosa culture(PF), on the production performance and intestinal microflora in laying hens. One hundred and sixty ISA Brown layers, 21 weeks of age, were randomly allotted to four dietary treatments, with four replicates per treatment. Dietary treatments consisted of four levels (0, 0.1, 0.3, and 0.5%) of PF added to a com-soybean meal based diet. Egg production, egg weight, feed intake and fred conversion ratio(FCR) were measured. Egg qualifies were examined at 25th and 29th weeks of age. A metabolism trial was conducted following the feeding trial, during which intestinal microflora, nutrient digestibility and fecal NH3 gas emission were measured. Egg production of birds fed 0.1 and 0.3% PF were significantly higher than those from birds fed 0 and 0.5% PF(P<0.05). Daily egg mass of 0.3% PF increased significantly compared to that of 0% PF. There was no difference in egg weight among all treatments. Feed conversion ratio was significantly improved as the PF level increased. No significant difference was found in eggshell quality and Haugh unit at both 25 and 29 weeks of age. Viable count of ileal Lactobacillus spp. increased significantly as the rf level increased. However, the total number of yeast and anaerobes in ileum were similar among all treatments. Cecal Lactobacillus spp. and yeast counts showed no difference among all treatments. Fecal NH$_{3}$ gas emission of layers fed PF decreased significantly by the PF supplementation. From the result of this experiment, it could be concluded that dietary supplementation of the live yeast Pichia farinosa improves the laying performance and decreases the fecal ammonia gas emission.

• Journal of Aquaculture
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• v.4 no.1
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• pp.1-12
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• 1991

A series of rearing experiments were conducted to determine the growth rates and feed conversion efficiencies of tilapia in accordance with body size or age in nearly total closed system glass aquariums ($270\;\ell$ each in water volume) and concrete tanks ($4000\;\ell$) from April 10 to October 16, 1987. The fish used for the experiments was a Japanese strain of Oreochromis niloticus, and the size of the fish ranged from 7 g to more than 1,000 g in body weight. The starting stocking rates for each experimental lot were 10 to 20 kg in the glass aquarium ($3.7{\%}$ to $7.4{\%}$ of water volume) and 200 kg in the concrete tank ($5{\%}$ of water volume). A single experimental rearing term was 14 days with slight variations on occasions. Water temperature was designed to be kept at $26^{\circ}C$ but slight fluctuations were inevitable. Dissolved oxygen level was designed to be maintained at around $3\;mg/\ell$, but it also showed some variations. The ammonia level in the glass aquarium section once reached up to $18\;mg/\ell$, but generally remained at around $4\;mg/\ell$, and in the concrete tank section it was maintained at around $1\;mg/ell$. The feed was composed of mainly soybean meal with a small amount of fish meal as the protein source, and the crude protein content was about $32{\%}$. Mean daily growth rate was $3.5{\%}$ of body weight with 0.9 in food conversion ratio in the glass aquarium when the mean weight of fish was around 10 g with gradually reduced performances as the fish grew bigger. When the mean weight was 800 g, mean daily growth rate was $0.5{\%}$ with about 1.5 in food coversion for fish in the glass aquarium, and $0.8{\%}$ and 1.6 for fish in the concrete tank, respectively. According to the mean growth rate obtained from this experiment, it was calculated that the fish reared in the concrete tank require 223 days from 50 g to reach 1,000 g which is the ideal size for market in Korea, at the conditions provided as above, and 302 days from 10 g fingerlings to 800 g fish in the glass aquarium conditions of the closed recirculating water system.