• Journal of Animal Science and Technology
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• v.59 no.6
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• pp.14.1-14.9
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• 2017

Background: Garlic and its constituents are reported to have been effective in reducing methane emission and also influence glucose metabolism in body; however, studies in ruminants using garlic leaves are scarce. Garlic leaves contain similar compounds as garlic bulbs, but are discarded in field after garlic bulb harvest. We speculate that feeding garlic leaves might show similar effect as garlic constituents in sheep and could be potential animal feed supplement. Thus, we examined the effect of freeze dried garlic leaves (FDGL) on rumen fermentation, methane emission, plasma glucose kinetics and nitrogen utilization in sheep. Methods: Six sheep were fed Control diet (mixed hay and concentrate (60:40)) or FDGL diet (Control diet supplemented with FDGL at 2.5 g/kg $BW^{0.75}$ of sheep) using a crossover design. Methane gas emission was measured using open-circuit respiratory chamber. Plasma glucose turnover rate was measured using isotope dilution technique of [$U-^{13}C$]glucose. Rumen fluid, feces and urine were collected to measure rumen fermentation characteristics and nitrogen utilization. Result: No significant difference in rumen fermentation parameters was noticed except for rumen ammonia tended to be higher (0.05 < P < 0.1) in FDGL diet. Methane emission per kg dry matter ingested and methane emission per kg dry matter digested were lower (P < 0.05) in FDGL diet. Plasma glucose concentration was similar between diets and plasma glucose turnover rate tended to be higher in FDGL diet (0.05 < P < 0.1). Nitrogen retention was higher (P < 0.05) and microbial nitrogen supply tended to be higher (0.05 < P < 0.1) in FDGL diet. Conclusion: FDGL diet did not impair rumen fermentation, improved nitrogen retention; while absence of significant results in reduction of methane emission, glucose turnover rate and microbial nitrogen supply, further studies at higher dose would be necessary to conclude the merit of FDGL as supplement in ruminant feedstuff.

• Bulletin of the Korean Chemical Society
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• v.24 no.3
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• pp.285-290
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• 2003

An analytical method for the simultaneous determination of trace Ge, As and Se in biological samples by inductively coupled plasma/mass spectrometry has been investigated. The effects of added organic gas into the coolant argon gas on the analyte signal were studied to improve the detection limit, accuracy and precision. The addition of a small amount of methane (10 mL/min.) into the coolant gas channel improved the ionization of Ge, As and Se. The analytical sensitivity of the proposed Ar/CH₄system was superior by at least two-fold to that of the conventional Ar method. In the present method, the detection limits obtained for Ge, As and Se were 0.014, 0.012 and 0.064 ㎍/L, respectively. The analytical reliability of the proposed method was evaluated by analyzing the certified standard reference materials (SRM). Recoveries of 99.9% for Ge, 103% for As, 96.5% for Se were obtained for NIST SRM of freeze dried urine sample. The proposed method was also applied to the biological samples.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.3
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• pp.287-296
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• 2013

To decompose carbon dioxide, which is a representative greenhouse gas, a plasma torch was designed and manufactured. To examine the characteristics of carbon dioxide decomposition via plasma discharge, a case wherein pure carbon dioxide was supplied and a case wherein methane and/or $TiCl_4$ were injected as additives were investigated and compared. The carbon dioxide and methane conversion rate, energy decomposition efficiency, produced gas concentration, carbon monoxide and hydrogen selectivity, carbon-black and $TiO_2$ were also investigated. The maximum carbon dioxide conversion rate was 28.9% when pure carbon dioxide was supplied; 44.6% when $TiCl_4$ was injected as am additive; and 100% percent when methane was injected as an additive. Therefore, this could be explained that the methane injection showed the highest carbon dioxide decomposition. Furthermore, the carbon-black and $TiO_2$ were compared with each commercial materials through XRD and SEM. It was found that the carbon-black that was produced in this study is similar for commercial materials. It was found that the $TiO_2$ that was produced in this study is suitable for photocatalyst and pigment because it has mixed anataze and rutile.

• Journal of Surface Science and Engineering
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• v.29 no.5
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• pp.487-493
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• 1996

Diamond films were grown at lower temperatures (630-813K) on Si, Al (1100P), and Al-Si(8A, 8B, BC) alloy substrates using improved microwave plasma CVD apparatus in a mixed methane and hydrogen plasma. Improved microwave plasma CVD apparatus equipped water cooled substrate holder and the substrates were set up lower position than bottom line of the applicator waveguide. When the methane concentration was high and growth was conducted at lower pressures the diamond films were synthesized. Moreover the deposits on the scratched substrates formed flat surfaces consisting of fine grains. XRD results, the deposits were identified to cubic diamond. An analysis using Raman spectroscopy, further confirmed that diamond films deposited on the Si substrates were high quality. The deposits on the Al substrates, in contrast, contained amorphous carbon. While the quality of the deposits on the Al-Si substrates were differed with the substrate alloys.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.10
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• pp.1037-1043
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• 1990

Diamond thin films were synthesized from the mixed gases of methane and hydrogen on silicon substrates by RF plasma chemical vapor deposition and deposited films were investigated by SEM, X-ray diffractometry and Raman spectroscopy. It is found that high quality diamond-like carbon films were successfully synthesized by PECVD under the deposition condition of 1-10 vol% of methane concentration, 0.15-0.4torr of reactor pressure, 500W of RF power, and 5-20hr of reaction time. Especially, cubo-octahedral diamond-like carbon particles were synthesized by employing 1.0 vol % of methane concentration and 0.4torr of the reactor pressure.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.149-150
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• 1989

Diamond thin films were synthesised from the mixed gases of $CH_4$ and $H_2$ on silicon substrate by R.F plasma CVD and films deposited were investigated by SEM. XRD and Raman spectroscope. From these result, cubo-octahedral diamond particles were synthesised under the following condition: methane concentration. 1.0vol% ; pressure of reactor, 0.3torr ; R.F power, 500W ; reaction time, 20hr.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.7
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• pp.552-556
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• 1998

Diamond thin films were deposited on Si substrate using $CH_4 and H_2$mixed gas by RF plasma CVD. Prior to deposition, the substrate surface was mechanically scratched with the diamond paste of $3{\mu}m$ to improve the density of nucleation sites. The microstructure of diamond films deposited with methane(0.5%~2%) at the reaction pressure ranging from 20 torr to 50torrr were studied by a scanning electron microscope. It was observed in the deposited diamond films that the nucleation density decreased and crystallinity increased with decreasing the methane concentration. However, the nucleation density and crystallinity were decreased with decreasing the process pressure.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.4
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• pp.534-540
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• 2003

This study was conducted to investigate the effect of supplementation of galacto-oligosaccharides (GOS) on methane emission, nutrient digestibility, energy utilization and blood metabolites by Holstein cows fed silages. In two sequential digestion and respiratory trials, two non-lactating Holstein cows were arranged to a balanced incomplete block design. Experimental diets consisted of two silage types; orchardgrass (Dactylis glomerata L.) based silage (OS), mixed silage (orchardgrass based silage and alfalfa (Medicago sativa L.) silage) (MS), while two GOS levels were without supplementation (0) and 2% of dry matter intake supplementation (2). Four combination diets were OS-0, OS-2, MS-0 and MS-2. Significant effects of silage types and GOS supplementation levels were not observed for DM and OM intake. Whereas the digestibility of OM, NDF and ADF was significantly (p<0.05) higher in cows fed OS with and without GOS compared cows fed MS diets. As percentage of GE intake, fecal energy loss for OS diets was significantly (p<0.05) declined than for MS diets. In contrast, cows fed MS diets had lower (p<0.05) urine energy loss as a proportion of GE intake compared to OS diets. Energy loss as CH4 and heat production was numerically increased when cows fed both OS and MS with GOS supplementation. Compared to OS, CH4 emission in cows fed MS was numerically decreased by 10.8 %. Methane conversion ratio (energy loss as CH4 per unit of GE intake) for OS-0, OS-2, MS-0 and MS-2 were 7.1, 7.2, 6.8 and 7.0, respectively. Plasma of glucose and urea-N concentration were significantly (p<0.05) elevated from 1 h to 6 h after feeding, otherwise total protein in plasma was declined (p<0.01) at 6 after feeding.