• Asian-Australasian Journal of Animal Sciences
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• v.28 no.5
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• pp.654-661
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• 2015

Two experiments were conducted to determine the digestible energy (DE) and metabolizable energy (ME) content of 19 rice bran samples and to develop prediction equations for DE and ME based on their chemical composition. The 19 rice bran samples came from different rice varieties, processing methods and regions. The basal diet was formulated using corn and soybean meal (74.43% corn and 22.91% soybean meal and 2.66% vitamins and minerals). The 19 experimental diets based on a mixture of corn, soybean meal and 29.2% of each source of rice bran, respectively. In Exp. 1, 108 growing barrows ($32.1{\pm}4.2kg$) were allotted to 1 of 18 treatments according to a completely randomized design with 6 pigs per treatment. The treatment 1 was the control group which was fed with basal diet. The treatments 2 to 18 were fed with experimental diets. In Exp. 2, two additional rice bran samples were measured to verify the prediction equations developed in Exp. 1. A control diet and two rice bran diets were fed to 18 growing barrows ($34.6{\pm}3.5kg$). The control and experimental diets formulations were the same as diets in Exp. 1. The results showed that the DE ranged from 14.48 to 16.85 (mean 15.84) MJ/kg of dry matter while the ME ranged from 12.49 to 15.84 (mean 14.31) MJ/kg of dry matter. The predicted values of DE and ME of the two additional samples in Exp. 2 were very close to the measured values.

• Journal of the Korean Chemical Society
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• v.33 no.4
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• pp.337-342
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• 1989

Gasless combustion is a vigorous exothermic reaction ignited directly in solid mixture, similar to Thermit reaction. The gasless combustion synthesis has the advantages of rapid processing, energy saving, low processing cost, and high purity of products. The Ti$Si_x$(x = 0.6, 0.8, 1.0, 2.0) systems are prepared by the gasless combustion synthesis without external sintering process. The crystallographic structures of $Ti_5Si_3$, $Ti_5Si_4$ are hexagonal and tetragonal system, respectively. Those of TiSi, $TiSi_2$ are orthorhombic systems. The results of X-ray analysis agree with the JCPDS data. The combustion modes of all combustion reactions are steady state combustions, and the propagation velocities of the combustion waves of $Ti_5Si_3$, $Ti_5Si_4$ and TiSi are greater than 0.6 cm/sec and that of $TiSi_2$ is 0.28 cm/sec.

• Membrane Journal
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• v.5 no.1
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• pp.35-43
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• 1995

For several years lots of attempts have been made to establish the liquid membrane-based techniques for separations of gas mixtures especially containing carbon dioxide. A more effective system to separate $CO_{2}$ from flue gases, a circulatory hollow-fiber membrane absorber(HFMA) consisting of absorption and desorption modules with vacuum mode, has been considered in this study. Gas-liquid mass transfer has been modeled on a membrane module with non-wetted hollow-fibers in the laminar flow regime. The influence of an absorbent flow rate on the separation performance of the circulatory HFMA can be predicted quantitatively by obtaining the $CO_{2}$ concentration profile in a tube side. The system of $CO_{2}/N_{2}$ binary gas mixture has been studied using pure water as an(inert) absorbent. As the absorbent flow rate is increased, the permeation flux(i.e., defined as permeation rate/membrane contact area) also increases. The enhanced selectivity compared to the previous results, on the other hand, shows the decreasing behavior. It has been found obviously that the permeation flux depends on the variations of pressure in gas phase of desorption module. From an accurate comparison with the results of conventional flat sheet membrane module, the advantageous permeability of this circulatory HFMA can be clearly ascertained as expected. Our efforts to the theoretical model will provide the basic analysis on the circulatory HFMA technique for a better design and process.

• Resources Recycling
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• v.23 no.5
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• pp.44-54
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• 2014

A standard plastic garbage bag which was discarded from Incheon Metropolitan City was composed of 4.5% recyclable resources (aluminum cans 0.2%, steel cans 2.5%, glass 1.8%), 92.5% resources with recoverable energy (papers 23.0%, plastics 15.5%, combustible etc. 54.0%) and 3.0% non-combustible etc. Recycling is more effective than landfilling for aluminum cans, steel cans, and glass. The energy recovery process using solid refuse fuel (SRF) is more effective than incineration for papers and plastics. Incineration is more effective than recycling for combustible etc. 2,068,948 Million Btu of total energy savings and 21,008 $MTCO_2E$ of total GHG reductions were obtained by the application of the proposed scheme. The total energy savings were equivalent to an economic benefit of 422 billion won per year. The total GHG reductions were equivalent to a GHG benefit of 4,119 passenger cars not running per year. The lower calorific value of the combustible materials was obtained to be 1,936 kcal/kg of papers, 5,079 kcal/kg of plastics and 2,462 kcal/kg of combustible other resources, respectively. If papers and plastics are properly mixed, the mixture can be used as SRF. The lower calorific value of combustible other resources does not meet the quality criteria for refuse derived fuel, therefore its components are inappropriate to used as solid refuse fuel.

• Membrane Journal
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• v.23 no.1
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• pp.1-11
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• 2013

Poly(ether imide) (PEI)-poly(dimethylsioxane) (PDMS) composite membranes and their modules were prepared, which are capable of selective $CO_2$ separation from the mixture gas. The gas flow rate, concentration, recovery ratio of $H_2$ and removal ratio of $CO_2$ outflowing by stage-cut were characterized at $25^{\circ}C$ and the constant pressure. In addition, to increase the recovery ratio of $H_2$, one stage, two stage series connection, and three stages series + parallel connection tests were carried out. When the stage-cut was 0.32 for the three stages connection operation, the concentration $H_2$ of the produced gas and the recovery ratio of $H_2$ was 97% and 85%, respectively. And also the removal ratio of $CO_2$ was 90% was obtained and the recycled gas concentration was similar with that of the feed gases.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.2
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• pp.117-122
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• 2009

This study was carried out to investigate applicability of Spent Mushroom Media(SMM) as horticultural nursery media. After the mushroom has been harvested, the SMM contains a lot of organic material, different microorganism and high density of mushroom hypha. The pH, phosphate and exchangeable cation concentrations of SMM of Flammulina velutipes were higher than those of any other treatment. The CEC and $NH_4-N$ were the highest in SMM of bottle-cultivated oyster mushroom (Pleurotus ostreatus). Bacteria and fungi showed the highest density in SMM of Flammulina velutipes. Most dominant bacteria were Microbacterium sp., Rhodococcus sp. and Agrobacterium sp. in SMM of Flammulina velutipes and Bacillus sp., Pseudomonas sp., Curtobacterium sp. and Microbacterium sp. in that of Pleurotus eryngii. The SMM contained high density of mushroom hypha that inhibited germination of seed and growth of young seedlings. Therefore, composting process of the SMM is indispensible to decline of vitality of mushroom hypha. The SMM of Flammulina velutipes with 0~30% vermiculite showed high germination rate in red pepper and chinese cabbage seeds. SMM of Pleurotus eryngii with 20% vermiculite showed 100% germination rate in red pepper seeds, but chinese cabbage seeds nearly failed to germinate with 30% vermiculite. The growth of red pepper was increased according to increasing mixture ratio of vermiculite. Accordingly, we concluded that SMM of Flammulina velutipes contained 0~30% of vermiculite can be used to horticultural growth bed for red pepper.

• Journal of the Mineralogical Society of Korea
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• v.20 no.1 s.51
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• pp.1-6
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• 2007

Hectorite was synthesized by a two-step hydrothermal process from $Mg(OH)_{2}$, water glass (${\sim}30\;wt%\;SiO_{2}$) and Li-compound at $90{\pm}5^{\circ}C$. The product shows excellent dispersion and swelling properties. The mixture of the starting materials was heated in a glass vessel for the first reaction with continuous stirring and the pH of the solution was adjusted to $6{\sim}8$, resulting in the formation of a precursor of hectorite. The excess salt components were washed out from the resulting slurry and then was matured in the glass vessel for the 2nd reaction. Li compound was added during the reaction. After a 10 h retention, the gel of hectorite was formed. The XRD pattern of the synthesized one was coincided with that of natural hectorite and SEM study revealed uniform grains 50 m in diameter. The d001 basal spacing of the product moved from 12 to $17.4\;{\AA}$ after glycolation treatment. The measured value of CEC and the swelling capacity was 90 cmol/kg and $60{\sim}70\;mL/2\;g$, respectively.

• Korean Journal of Environmental Agriculture
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• v.27 no.4
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• pp.368-372
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• 2008

Composting is a good strategy for management of livestock manure. However, it leads to large ammonia emissions and has a potential phosphorus runoff due to high content of soluble phosphorus. The objective of this study was to evaluate the efficiency of alum on reducing ammonia emissions and stabilizing phosphorus during composting of pig manure. For this study, alum was applied at rates of 0 (No-Alum), 1.0 (Alum-L), and 3.0 (Alum-H) g Al $kg^{-1}$ pig manure and sawdust mixture (fresh matter basis). The thermophilic stage was quickly achieved in Alum-L and No-alum treatment, but it was delayed to 5 days in Alum-H treatment. The thermophilic stage was maintained for 2 weeks in all treatment. The pH of compost treated with alum remained below 8.0 for the 35 d but it was above 8.0 in No-Alum treatment. For the first 15 days of composting process, 93, 87, and 58% of total ammonia emissions were occurred in No-Alum-L and Alum-H, respectively. The Alum-H and Alum-L treatments reduced $NH_3$ volatilization by 31 and 78% compared with No-Alum treatment. Alum treatments shifted manure P form $H_2O$ and $NaHCO_3$ extractable P into NaOH extractable P which is very stable under acid and alkaline condition. Therefore, alum is a good chemical amendment for reducing ammonia emission during composting and potential losses of P following compost applications.

• Applied Chemistry for Engineering
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• v.19 no.2
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• pp.157-160
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• 2008

The generation of high-purity hydrogen from hydrocarbon fuels is essential for efficient operation of fuel cell. In general, most feasible strategies to generate hydrogen from hydrocarbon fuels consist of a reforming step to generate a mixture of $H_2$, CO, $CO_2$ and $H_2O$ (steam) followed by water gas shift (WGS) and CO clean-up steps. The WGS reaction that shifts CO to $CO_2$ and simultaneously produces another mole of $H_2$ was carried out in a two-stage catalytic conversion process involving a high temperature shift (HTS) and a low temperature shift (LTS). In a typical operation, gas emerges from the reformer is taken through a high temperature shift catalyst to reduce the CO concentration to about 3~5%. The HTS reactor was designed and tested in this study to produce hydrogen-rich gas with CO to a range of 2~4%. The iron based catalysts (G-3C) was used for the HTS to convert the most of CO in the effluent from the partial oxidation (POX) to $H_2$ and $CO_2$ at a relatively high rate. Parametric screening studies were carried out for variations of the following variables: reaction temperature, steam flow rate, components ratio ($H_2/CO$), and reforming gas flow rate.

• Applied Chemistry for Engineering
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• v.19 no.4
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• pp.413-420
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• 2008

Over the past decade, there have been significant advancement in the field of electrospinning area. This study has focused on preparing yarn using polycarbonate (PC) nanofibers including modified multi-walled carbon nanotube (mMWNT) by solution electrospinning process using the mixture of solvents consisting of tretrahydronfuran (THF) and N,N-dimethylformamide (DMF). In order to enhance the dispersion, MWNT was chemically modified. TEM analysis for the prepared PC/mMWNT nanofibers reveals that mMWNT was well-dispersed into the PC nanofiber matrix. Also with increasing contents of mMWNT, thermal stability of PC/mMWNT nanofibers was improved than that of PC nanofibers. Moreover when 3 to 5 wt% of mMWNT was added, the nanofibers showed good electrical properties expecting antistatic effect, ranging 109.1~109.5 ${\Omega}$. It was confirmed that the multi-filament fibers using PC/mMWNT had $60{\sim}100{\mu}m$ in diameter and 4~5 cm in length.