• Journal of Korean Society for Atmospheric Environment
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• v.14 no.1
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• pp.63-72
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• 1998

Simultaneous CO and $C_3H_6$ oxidation was carried out over noble metal supported monolith catalysts in a flow thorugh type reactor at the temperature ranging from room temperature to $500^\circ$C. Pt and Pd were selected as major active species, 10wt% of Ce was impregnated as an additive and alumina and silica were used as supports. The reactant gases were simulated and the reaction products were analyzed by on-line G.C.. EDX, SEM, TGA, XRD and optical microscope were used to analyze the characteristics of the prepared catalysts. Under the given conditions in this study, the catalysts supported on alumina showed better activity for CO oxidation, while Pd catalysts showed better activity for $C_3H_6$ oxidation. The improvement of conversion due to increase in thermal stability possibily by Ce addition was observed only for Pt catalysts.

• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.162-165
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• 2002

With the objective of identifying the commercial potential of new direct-fed microbials, several temperature-tolerant strains were isolated from cane molasses at $39^{\circ}C$ and tested for their tolerance to pH, bile salts, and a mixture of volatile fatty acids (acetic acid:propionic acid:butyric acid=6.5:2.0:1.5). It was found that the isolated strain DY 252 grew very well up to pH 2.0 and was resistant to relatively high concentrations of bile salts. Among the strains tested, DY 252 was least inhibited by the addition of volatile fatty acids to the growth medium at $39^{\circ}C$. Accordingly, it would appear that strain DY 252, identified as yeast Issatchenkia orientalis, may be a potential candidate for use as a microbial feed additive.

• Journal of Powder Materials
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• v.28 no.2
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• pp.120-126
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• 2021

In this study, AlSi10Mg alloy powders are synthesized using gas atomization and sieving processes for powder bed fusion (PBF) additive manufacturing. The effect of nozzle diameter (ø = 4.0, 4.5, 5.0 and 8.0 mm) on the gas atomization and sieving size on the properties of the prepared powder are investigated. As the nozzle diameter decreases, the size of the manufactured powder decreases, and the uniformity of the particle size distribution improves. Therefore, the ø 4.0 mm nozzle diameter yields powder with superior properties. Spherically shaped powders can be prepared at a scale suitable for the PBF process with a particle size distribution of 10-45 ㎛. The Hausner ratio value of the powder is measured to be 1.24. In addition, the yield fraction of the powder prepared in this study is 26.6%, which is higher than the previously reported value of 10-15%. These results indicate that the nozzle diameter and the post-sieve process simultaneously influence the shape of the prepared powder as well as the satellite powder on its surface.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.10
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• pp.1466-1472
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• 2012

A bacterial isolate derived from soil samples near a cattle farm was found to display extracellular phytase activity. Based on 16S rRNA sequence analysis, the strain was named Bacillus sp. T4. The optimum temperature for the phytase activity toward magnesium phytate (Mg-$InsP_6$) was $40^{\circ}C$ without 5 mM $Ca^{2+}$ and $50^{\circ}C$ with 5 mM $Ca^{2+}$. T4 phytase had a characteristic bi-hump two pH optima of 6.0 to 6.5 and 7.4 for Mg-$InsP_6$. The enzyme showed higher specificity for Mg-$InsP_6$ than sodium phytate (Na-$InsP_6$). Its activity was fairly inhibited by EDTA, $Cu^{2+}$, $Mn^{2+}$, $Co^{2+}$, $Ba^{2+}$ and $Zn^{2+}$. T4 phytase may have great potential for use as an eco-friendly feed additive to enhance the nutritive quality of phytate and reduce phosphorus pollution.

• Asian-Australasian Journal of Animal Sciences
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• v.3 no.3
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• pp.231-242
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• 1990

A study is reported which investigated the additive nature of digestible energy (DE) from dietary nutrients and to estimate the relative energy values of different energy-yielding nutrients in practical trout diets. A growth study was conducted over 12 weeks with 6 diets. Rainbow trout (Oncorhynchus mykiss) were fed diets once a day ad libitum. Digestible energy values determined and calculated had direct relationship indicating additive nature of such values for feed ingredients. Overall growth performance was best in a diet containing 33% digestible protein (DP) with a DP/DE ratio of 18.6. A reduction in digestible protein level with the same DP/DE rat io led to a significant decrease in growth and feed efficiency. The increase of 7% of lipid with concomitant decrease in protein resulted in the relative gain of 130% in growth and nutrient retention, suggesting that 1 g of lipid is equal to about 1.3 g of proteins in terms of net energetic value. Replacement of 10% of dietary lipid by carbohydrates led to a slight decrease in energy retention efficiency but to a great increase in lipid retention efficiency (130%) showing that dietary carbohydrates led to increased lipogenesis.

• KSBB Journal
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• v.27 no.5
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• pp.319-323
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• 2012

Vitamin C or L-ascorbic acid, an essential nutrient for humans with antioxidative property, was coated with natural wax to be used as functional additives for cosmetics. Coating of vitamin C was performed using carnauba wax and olive wax in self-designed reaction chamber for 60 min. The yield of coated vitamin C with carnawuba wax and olive wax were up to $94.6{\pm}1.2%$ and $82.5{\pm}1.4%$, respectively. The stability of the carnauba wax-coated vitamin C in the lotion was improved 17.8% than that of uncoated vitamin C during 30 day storage at $25^{\circ}C$. Color and the layer separation of the lotion added with the coated vitamin C showed better property than with the uncoated vitamin C. The coated vitamin C can be applied to cosmetic ingredients as a stable additive.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.3
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• pp.21-29
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• 2011

Recently, the use of recycled fibers was increased in order to replace the virgin pulp for low production cost and forest conservation. However, the recycled fibers decreases drainage rate, papermaking efficiency and product quality by short fibers and low wettability because of hornification. To overcome the limitation of low drainage rate, the technology of organic fillers were applied. Wooden fillers gave high bulk and stiffness of paper, but they reduced the strength of paper. In order to improve strength properties 4 types of strength additives were added and analyzed. Cationic starch, branched strength additive, linear wet strength additive, and linear dry strength additive were used. The drainage rate and paper properties such as bulk, air permeability and tensile strength were measured. As results of analysis, addition of branch type of strength agent such as C-starch was effective than linear type of strength agent in the drainage rate. Nevertheless there was no effect on the drainage rate by adding the pretreated wooden fillers. By adding the pretreated wooden fillers, bulk, air permeability and tensile strength of handsheets were improved with low dosage than non-pretreated fillers.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.07a
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• pp.107-114
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• 2003

This study investigated the effect of 2-methoxy ethanol (2-Me) non-solvent as additive included in casting solution. Macroporous polymer membranes were prepared by using polyethersufone (PES)/N-methyl-2-pyrrolidone (NMP)/2-Me casting solution and water coagulant. The phase separation co-process of the vapor-induced phase separation (VIPS) and liquid-induced phase separation (LIPS) were used by means of membrane preparation method. The pore size and pore size distribution were controlled with additive (non-solvent), and measured with Automated Perm Porometer. By increasing additive (non-solvent) in the casting solution, the membranes produced changed from finger structure to sponge structure. That is due to the different diffusion rates. At slow diffusion process, sponge-like structure was formed and at fast diffusion process, finger-like structure was formed. Also relative humidity, evaporation time, temperature of casting solution and coagulation bath etc. had effects on the pore size distribution and the porosity of the membrane.

• KSBB Journal
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• v.25 no.5
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• pp.443-448
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• 2010

Coated citric acid as an acidulant was prepared to be used as a stable food additive. Sensory evaluation of chocolate products with the coated acidulant additive was performed to improve sensory preference tendency in chocolate product. When the ratio of coated acidulant was varied on the preparation of dark (0, 1, 2 wt%), milk (0, 1, 2 wt%) and white (0, 2, 4, 6 wt%) chocolate, 1 wt% (dark and milk) or 2 wt% (white) addition showed better preference than that of 0% sample in overall acceptability. Under the condition of the same coated acidulant content (1% or 2%), the white chocolate showed best sensory evaluation result in sweet, sour taste and overall acceptability.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.2
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• pp.177-184
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• 2021

In this study, the effects of ground granulated blast furnace slag(GGBFS) and expansive additive(EA) on early strength mortar were examined for the purpose of reducing carbon and improving cement performance. As a result, ealry strength Portland cement(EPC) tended to decrease in flow compared to ordinary Portland cement(OPC), but binder with EPC and GGBFS was possible to obtain higher liquidity than OPC. EPC showed higher compressive strength and shrinkage than OPC. The compressive strength of specimen with EPC and GGBFS was reduced proportionally to the replacement ratio of GGBFS. The replacement ratio of GGBFS above the compressive strength equivalent to OPC was higher under low temperature conditions. The use of GGBFS resulted in high shrinkage compared to OPC, and this characteristic was even greater under low temperature conditions. The shrinkage of specimen with EA was decreased in early ages, but was higher than the OPC in long-term ages.