• Asian-Australasian Journal of Animal Sciences
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• v.27 no.3
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• pp.330-341
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• 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).

• Korean Journal of Environmental Agriculture
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• v.26 no.2
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• pp.141-148
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• 2007

Fly ash, a by-product of the coal-burning industry, and a potential source of ferro-alumino-silicate minerals, which contains high amount of ferric oxide and manganese oxide (electron acceptors), was selected as soil amendment for reducing methane $(CH_4)$ emission during rice cultivation. The fly ash was applied into potted soils at the rate of 0, 2, 10, and 20 Mg $ha^{-1}$ before rice transplanting. $CH_4$ flux from the potted soil with rice plants was measured along with soil Eh and floodwater pH during the cropping season. $CH_4$ emission rates measured by closed chamber method decreased gradually with the increasing levels of fly ash applied but rice yield significantly increased up to 10 Mg $ha^{-1}$ application level of the amendment. At this amendment level, total seasonal $CH_4$ emission was decreased by 20% along with 17% rice grain yield increment over the control. The decrease in total $CH_4$ emission may be attributed due to suppression of $CH_4$ production by the high content of active and free iron, and manganese oxides, which acted as oxidizing agents as well as electron acceptors. In conclusion fly ash could be considered as a feasible soil amendment for reducing total seasonal $CH_4$ emissions as well as maintaining higher grain yield potential under optimum soil nutrients balance condition.

• Microbiology and Biotechnology Letters
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• v.24 no.3
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• pp.364-370
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• 1996

Sediments collected from the Jungnang-cheon and its tributaries were used to enumerate anaerobic bacteria by most probable number (MPN) methods. A simple method was developed to detect ferrous ion in the culture fluid in order to count the number of iron ion reducers, and sulfate-reducing bacteria (SRB) and methanogens were detected by the presence of FeS precipitate in the culture or methane in the head space, respectively. The numbers of iron reducer was in the range of 10$^{7}$ - 10$^{8}$ /g in the sediment of the stream containing higher organic content than the tributaries. The sediments of tributaries were analyzed to contain iron reducers less than 10$^{7}$ cells/g. With one exception the numbers of SRB and methanogens were less than 10$^{3}$ cells/g in the sediment. From these results it is concluded that organics in the sediment support the growth of iron reducers, which out-compete SRB and methanogens.

• Macromolecular Research
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• v.15 no.1
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• pp.10-16
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• 2007

In this work, we prepared epoxy/BMI composites by using N,N'-bismaleimide-4,4'-diphenylmethane (BMI), epoxy resin (diglycidyl ether of bisphenol-A (DGEBA)), and 4,4'-diamino diphenyl methane (DDM). The thermal properties and water sorption behaviors of the epoxy and BMI composites were investigated. For the epoxy/BMI composites, the glass transition and decomposition temperatures both increased with increasing BMI addition, which indicates the effect of BMI addition on improved thermal stability. The water sorption behaviors were gravi-metrically measured as a function of humidity, temperature, and composition. The diffusion coefficient and water uptake decreased and the activation energy for water diffusion increased with increasing BMI content, indicating that the water sorption in epoxy resin, which causes reliability problems in electronic devices, can be diminished by BMI addition. The water sorption behaviors in the epoxy/BMI composites were interpreted in terms of their chemical and morphological structures.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.4
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• pp.903-911
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• 1994

This study addresses the phenomena of bubbling, icing, eruption, component varieties of the evaporated natural gas, and volumetric heat transfer coefficients obtained during the operation of a proposed LNG evaporator between LNG and water in direct contact. In the present investigation, the explosive and eruption phenomena within the water column were not observed during the entire operation of the heat exchanger. Compared with the natural gas produced by conventional LNG evaporator, the analysis of the gas produced by the direct contact LNG evaporator shows that nitrogen, methane, and ethane components were reduced by 0.002~0.007mol%(4~14%), 1.6~1.92mol%(1.9~2.3%) and 0.17~1.28mol%(1.1~8.4%) respectively, while the moisture content was rather increased by 0.51~0.76mol%. The maximum volumetric heat transfer coefficient of the direct contact heat exchanger was found to be $21, 800kW/m^3\cdotK$.

• Journal of Korean Society on Water Environment
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• v.18 no.4
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• pp.365-370
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• 2002

This study aims to study the effect of HRT and influent concentration on swine wastewater treatment using UASB(Upflow Anaerobic Sludge Blanket). Sample was separately collected from the piggery farm; urine(liquid part) and solid part to compare their treatment characteristics. Reactors were used two UASB(3.2 L) in this research under constant temperature ($35^{\circ}C$). Their operating conditions were as follows; Run 1(UASB ; HRT 6-days, 1 cycle/d), Run 2(UASB ; HRT 3-days, 1 cycle/d). Biogas was collected and analyzed using GC(HP-6890). By comparing the results of Run 1 and Run 2, the effect of HRT was investigated. The treatment efficiency of Run 1 which had longer HRT was higher than that of Run 2 in both solid and liquid parts of piggery sample. Methane content in collected biogas is more than 80%.

• Preventive Nutrition and Food Science
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• v.9 no.2
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• pp.187-189
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• 2004

To isolate a mutant strain which overproduces tryptophan, mutants of Candida rugosa were screened after EMS (ethyl methane sulfonate) mutagenesis. Fluorotryptophan, a tryptophan analogue, was used for selection of a tryptophan-overproducing mutant after mutagenesis. Among 50 mutants, several candidates were selected based on intracellular tryptophan content. Amino acid analysis results showed that C3 was the best strain because it had the highest amount of tryptophan among the mutants.

• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.781-785
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• 2012

This study was carried out to treat the thermal elutriated acids of piggery wastewater using UASB process. The UASB reactor was operated at an organic loading rate (OLR) of $7.4\;kgCOD/m^3-day$ (6.5 ~ 9.0). During the start-up period, the low COD removal efficiency (20%) was caused by shock loading and instability in the reactor. It was mainly due to the high concentration amounts of ammonia nitrogen, which caused inhibitory and toxic effects to toward the anaerobic bacteria. In steady state, the UASB reactor showed a SCOD removal efficiency of 71% and a VS removal efficiency of 39%. The gas production and methane content were 1.3 L/day $(0.21\;m^3\;CH^4/kg$ COD removed) and 77%, respectively.

• Journal of the Korean Ceramic Society
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• v.35 no.12
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• pp.1249-1256
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• 1998

${\beta}$-Silicon carbide(${\beta}$-SiC) whiskers could be synthesized by the carbothermal reduction of kaolin at tem-peratures between 1400 and 1500$^{\circ}C$. The whiskers were grown up to about 1150 of aspect ratio by VS mechanism (showing tapering tips) and to about 45 of that by VLS mechanism (showing round droplet tips) respectively. Hydrocarbon like methane in the reaction atmosphere promoted the formation of gaseous il-icon monoxide(SiO) from silicon dioxide(SiO2) and subsequently reacted with it to form whiskers. The for-mation of ${\beta}$-SiC whiskers increased with increasing carbon content(to 30 wt%) and reaction temperatures. The max. yield of ${\beta}$-SiC whiskers was 15% at 1500$^{\circ}C$ under 20%CH4/80%H2.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.3
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• pp.214-219
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• 1990

This study was conducted to characterize red worm(Lumbricus rubellus) and its cast reared six months using with pulp sludge, mixture of pulp sludge and methane sludge, and cow manure and methane sludge. The results obtained were as follows: 1. The optimum growth temperature ranged from $16^{\circ}C$ to $25^{\circ}C$ and monthly weight increase was about one kilogram per square meter. 2. The weight of red worm increased 9 to 11 percent reared with mixture of cow manure and methane sludge compared to pulp sludge. 3. Red worm contained large amount of amino acid, including. Lycine, which, might be a good source for a feed additive. 4. Yields of red worm cast ranged from 90 to 95 ton/10a/year on dry weight base. 5. CEC of red worm cast varied from 19.4 to 49.9 meg/100g and O.M content ranged from 26.4 to 35.1 percent. It contained lots of nutrients resulting in a good fertilizer source.