• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.1
• /
• pp.73-79
• /
• 2004

The objective of the present study was to determine whether ${\beta}$1-4 galacto-oligosaccharides (GOS) and Candida kefyr combined with nitrate as manipulators could suppress rumen methanogenesis without nitrate poisoning in sheep. Four rumen fistulated wethers were allocated to a $4{\times}4$ Latin square design. Nitrate (1.3 g $NaNO_3$ $Kg^{-0.75}$body weight) with and without GOS and Candida kefyr were administered into the rumen through fistula as a single dose 30 min after the morning meal. GOS and Candida kefyr were supplemented by sprinkling onto the feed and through rumen fistula, respectively. The four treatments consisted of saline, nitrate, nitrate plus GOS and nitrate plus GOS plus Candida kefyr. Physiological saline was used as the control treatment. Compared to saline treatment, the administration of nitrate alone resulted in a very marked decrease in rumen methanogenesis and an increase in rumen and plasma nitrite production and blood methaemoglobin formation consequently causing a decline in oxygen consumption, carbon dioxide production and metabolic rate. When compared to nitrate alone, the simultaneous administration of nitrate with GOS decreased nitrite accumulation in rumen and plasma and nitrate-induced methaemoglobin, while retaining low methane production. However, GOS could not fully restore metabolic parameters reduced by nitrate. When compared to the simultaneous administration of nitrate with GOS, the simultaneous administration of nitrate with GOS plus Candida kefyr lowered rumen methanogenesis to a negligible level, but did not decrease rumen and plasma nitrite accumulation as well as blood methaemoglobin formation. Thus, these results suggest that combination of nitrate with GOS may be a potent manipulator to suppress rumen methanogenesis with abating the hazards of nitratenitrite toxicity in ruminants.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.1
• /
• pp.73-79
• /
• 2016

The objective was to evaluate the effect of fodder tree species (FTS) with condensed tannin contents: Cordia elaeagnoides, Platymiscium lasiocarpum, Vitex mollis, and Haematoxylon brasiletto, on in vitro methane ($CH_4$) production at 24 h post incubation. The analysis was performed using the in vitro gas production technique, with three levels of inclusion/species: 600, 800, and 1,000 mg and with 4 replicates/species/level of inclusion. The substrate was incubated at $39^{\circ}C$, and the gas and $CH_4$ production were recorded at 4, 8, 12, and 24 h post incubation. The data collected was analyzed through Pearson correlation, polinomial regression and fixed effects models. There were negative correlations between FTS-total gas volume (r = -0.40; p<0.001); FTS-volume of $CH_4$ produced (r = -0.40; p<0.001) and between the inclusion level-volume of $CH_4$ produced (r = -0.20; p<0.001). As well as a positive correlation between hours post incubation-total gas volume (r = 0.42; p<0.001) and between hours post incubation-volume of $CH_4$ produced (r = 0.48; p<0.001). The FTS: C. elaeagnoides, V. mollis, and H. brasiletto have potential, in the three inclusion levels analyzed, to reduce $CH_4$ emission on in vitro trials (>32.7%), taking into account the total $CH_4$ production at 24 h of the forage used as reference (Avena sativa). It's suggested that C. elaeagnoides-according to its crude protein, neutral detergent fiber, and condensed tannins content- is the best alternative within the FTS analyzed, for feeding ruminants and for the control of $CH_4$ emissions during the dry season.

• Asian-Australasian Journal of Animal Sciences
• /
• v.25 no.6
• /
• pp.812-817
• /
• 2012

Nitrate can serve as a terminal electron acceptor in place of carbon dioxide and inhibit methane emission in the rumen and nitrate reducing bacteria might help enhance the reduction of nitrate/nitrite, which depends on the type of feed offered to animals. In this study the effects of three levels of sodium nitrate (0, 5, 10 mM) on fermentation of three diets varying in their wheat straw to concentrate ratio (700:300, low concentrate, LC; 500:500, medium concentrate, MC and 300:700, high concentrate, HC diet) were investigated in vitro using buffalo rumen liquor as inoculum. Nitrate reducing bacteria, isolated from the rumen of buffalo were tested as a probiotic to study if it could help in enhancing methane inhibition in vitro. Inclusion of sodium nitrate at 5 or 10 mM reduced (p<0.01) methane production (9.56, 7.93 vs. 21.76 ml/g DM; 12.20, 10.42 vs. 25.76 ml/g DM; 15.49, 12.33 vs. 26.86 ml/g DM) in LC, MC and HC diets, respectively. Inclusion of nitrate at both 5 and 10 mM also reduced (p<0.01) gas production in all the diets, but in vitro true digestibility (IVTD) of feed reduced (p<0.05) only in LC and MC diets. In the medium at 10 mM sodium nitrate level, there was 0.76 to 1.18 mM of residual nitrate and nitrite (p<0.01) also accumulated. In an attempt to eliminate residual nitrate and nitrite in the medium, the nitrate reducing bacteria were isolated from buffalo adapted to nitrate feeding and introduced individually (3 ml containing 1.2 to $2.3{\times}10^6$ cfu/ml) into in vitro incubations containing the MC diet with 10 mM sodium nitrate. Addition of live culture of NRBB 57 resulted in complete removal of nitrate and nitrite from the medium with a further reduction in methane and no effect on IVTD compared to the control treatments containing nitrate with autoclaved cultures or nitrate without any culture. The data revealed that nitrate reducing bacteria can be used as probiotic to prevent the accumulation of nitrite when sodium nitrate is used to reduce in vitro methane emissions.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.237.1-237.1
• /
• 2014

Etching is one of the most important steps in semiconductor manufacturing. In etch process control a critical task is to stop the etch process when the layer to be etched has been removed. If the etch process is allowed to continue beyond this time, the material gets over-etched and the lower layer is partially removed. On the other hand if the etch process is stopped too early, part of the layer to be etched still remains, called under-etched. Endpoint detection (EPD) is used to detect the most accurate time to stop the etch process in order to avoid over or under etch. The goal of this research is to develop a hardware and software system for EPD. The hardware consists of an Optical Plasma Monitor (OPM) sensor which is used to continuously monitor the plasma optical emission intensity during the etch process. The OPM software was developed to acquire and analyze the data to perform EPD. Our EPD algorithm is based on the following theory. As the etch process starts the plasma generated in the vacuum is added with the by-products from the etch reactions on the layer being etched. As the endpoint reaches and the layer gets completely removed the plasma constituents change gradually changing the optical intensity of the plasma. Although the change in optical intensity is not apparent, the difference in the plasma constituents when the endpoint has reached leaves a unique signature in the data gathered. Though not detectable in time domain, this signature could be obscured in the frequency spectrum of the data. By filtering and analysis of the changes in the frequency spectrum before and after the endpoint we could extract this signature. In order to do that, first, the EPD algorithm converts the time series signal into frequency domain. Next the noise in the frequency spectrum is removed to look for the useful frequency constituents of the data. Once these useful frequencies have been selected, they are monitored continuously in time and using a sub-algorithm the endpoint is detected when significant changes are observed in those signals. The experiment consisted of three kinds of etch processes; ashing, SiO2 on Si etch and metal on Si etch to develop and evaluate the EPD system.

• Herbal Formula Science
• /
• v.17 no.2
• /
• pp.53-63
• /
• 2009

Objective : To compare the contents of heavy metals, residual pesticides and sulfur dioxide before/after a decoction. Methods : The heavy metal contents before/after a decoction were measured by Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) and mercury analyzer. In order to analyze pesticides in 4 samples we used simultaneous multi-residue analysis of pesticides by GC/ECD, which was followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide ($SO_2$) were performed by Monier-Williams distillation method. Results: 1. The mean values of heavy metal contents (mg/kg) for the samples were as follows: Jaeumganghwa-tang (before decoction - Pb; 1.190, Cd; 0.184, As; 0.099 and Hg; 0.028, after decoction - Pb; .033, Cd; 0.003, As; 0.005 and Hg; 0.001), Yukmijiwhang-tang (before decoction - Pb; 0.484, Cd; 0.133, As; 0.053 and Hg; 0.009, after decoction - Pb; 0.065, Cd; 0.008, As; 0.007 and Hg; not detected), Bojungikgi-tang (before decoction - Pb; 0.863, Cd; 0.197, As; below 0.016 and Hg; 0.011, after decoction - Pb; 0.071, Cd; 0.009, As; 0.004 and Hg; 0.001) and Ssangwha-tang (before decoction - Pb; 1.511, Cd; 0.212, As; 0.094 and Hg; 0.016, after decoction - Pb; 0.029, Cd; 0.006, As; 0.005 and Hg; 0.0004). 2. Contents (mg/kg) of sulfur dioxide ($SO_2$) before a decoction in Jaeumganghwa-tang, Yukmijiwhang-tang and Ssangwha-tang exhibited 22.7, 107.3 and 5.5, respectively. However, contents of sulfur dioxide after a decoction in all samples were not detected. 3. Contents (mg/kg) of residual pesticides before/after a decoction in all samples were not detected. Conclusion : These results will be used to establish a criterion of heavy metals, residual pesticides and sulfur dioxide.

• The Journal of Korean Medicine
• /
• v.30 no.4
• /
• pp.108-117
• /
• 2009

Objective: To compare the contents of heavy metals, residual pesticides and sulfur dioxide before/after a decoction. Methods: The heavy metal contents before/after a decoction were measured by inductively-coupled plasma atomic emission spectrometer (ICP-AES) and mercury analyzer. In order to analyze pesticides in 5 samples we used simultaneous multi-residue analysis of pesticides by GC/ECD, which was followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide ($SO_2$) were performed by Monier-Williams distillation method. Results: 1. The mean values of heavy metal contents (mg/kg) for the samples were as follows: Sipjeondaebo-tang (before decoction - Pb; 1.163, Cd; 0.257, As; 0.080 and Hg; 0.016, after decoction - Pb; 0.059, Cd; 0.007, As; 0.006 and Hg; 0.0003), Palmul-tang (before decoction - Pb; 1.181, Cd; 0.242, As; 0.152 and Hg; 0.014, after decoction - Pb; 0.067, Cd; 0.008, As; 0.008 and Hg; 0.0003), Sagunja-tang (before decoction - Pb; 1.285, Cd; 0.283, As; 0.063 and Hg; 0.012, after decoction - Pb; 0.047, Cd; 0.009, As; 0.004 and Hg; not detected) and Samul-tang (before decoction - Pb; 1.025, Cd; 0.169, As; 0.099 and Hg; 0.013, after decoction - Pb; 0.065, Cd; 0.007, As; 0.010 and Hg; 0.001). 2. Contents (mg/kg) of residual pesticides before/after a decoction were not detected in any samples. 3. Contents (mg/kg) of sulfur dioxide ($SO_2$) before a decoction in Sipjeondaebo-tang, Palmul-tang, Sagunja-tang and Samul-tang exhibited 5.0, 6.0, 14.0 and 6.9, respectively. However, contents of sulfur dioxide after a decoction were not detected in any samples. Conclusion: These results will be used to establish a criterion for heavy metals, residual pesticides and sulfur dioxide.

• Analytical Science and Technology
• /
• v.13 no.2
• /
• pp.158-165
• /
• 2000

The purity of gypsum and quantitation of impurities of flue gas gypsum will not only play an important role in deciding of the optimal condition during a trial run of FGD (flue gas desulfurization), but also can be utilized in quality control of gypsum. The purity of gypsum can be determined from combined water, sulfur trioxide and calcium concentration. We found that the thermal analysis by TGA (thermogravimetric analysis) was the most accurate and convenient method to determine the purity of gypsum. This method will be done in a hour and the results were reproducible. On the other hand, the best way of the analysis of impurities in gypsum was fusion method using $LiBO_2$ as a fusion agent. We also determined the amount of $CO_2$ gas to analyze magnesium carbonate and calcium carbonate contents. The analyses of combined water by TGA, fusion method followed by ICP-AES (inductively coupled plasmaatomic emission spectroscopy) and determination of $CO_2$ amount can lead to more accurate and convenient method for gypsum analysis.

• Journal of Korean Society for Atmospheric Environment
• /
• v.34 no.1
• /
• pp.56-75
• /
• 2018

Korean Photochemical Assessment Monitoring Stations (PAMS) have been established since the late 2001 to monitor ambient air concentrations of VOC species, which would enhance understanding photo-chemical formation of ozone and subsequently contribute to developing efficient ozone control strategies. The present study aims at identifying major VOC species and examining their trends by analyzing PAMS monitoring data collected from the year 2006 to 2016. All the 18 PAMS sites operated by the Ministry of Environment were included in the study. PAMS monitored the 56 target VOC species, which are classified into four groups, alkenes, lower alkanes ($C{\leq}3$), higher alkanes ($C{\geq}4$), aromatics. The higher alkanes and aromatics dominated over the lower alkanes and alkenes in the type 2 and 3 PAMS sites except Joongheung site. N-butane was a major alkane species, toluene was a major aromatic species and most of VOCs showed decreasing trends in these sites. On the other hand, only the alkenes showed decreasing trends at the Joongheung site in Yeosu. Major sources of abundant species such as ethane, propane, n-butane, toluene were estimated by analyzing seasonal variations, correlation with other VOC species, and emission profiles. A major source of n-butane was identified as LPG cars, while major sources of toluene varied considerably from one site to another. The lower alkanes were composed of ethane and propane, both of which showed a strong seasonal variation, low in the summer and high in the winter, indicating that a major source might be the heating by gaseous fuels. Ozone formation potentials of VOC species were evaluated by applying MIR and POCP to the measured VOC species concentrations. Toluene contributed the most to total ozone forming potentials followed by m,p-xylene for all the type 2 and 3 PAMS sites except for two sites in Yeosu-Gwangyang. Ethylene and propylene were the first and second contributors to total ozone forming potentials at Joongheung site in Yeosu.

• The Korean Journal of Nuclear Medicine
• /
• v.23 no.2
• /
• pp.155-163
• /
• 1989

Regional cerebral perfusion was evaluated in 15 normal controls by single photon emission computed tomography using $^{99m}Tc$ HM-PAO. For quantitative analysis, 13 pairs of homologous region of interest (ROI) were drawn on three transverse slices matching the vascular territories and cerebral cortices, and normal values of 3 semiqunatitative indices including 'Right to left ratio'(R/L ratio), 'Regional index'(RI), and 'Region to cerebellum ratio'(R/cbll ratio) were calculated. Mean values of R/L ratios of homotogous regions were ranged from 0.985 to 1.023, and mean ${\pm}2$ s.d. of all regions did not exceed 11% of mean. Significant difference of RIs (mean count per voxel of a ROI/mean count per voxel of total ROIs) between regions were found (p<0.001) with highest values in occipital cortex and cerebellum. After attenuation correction, RIs in deep gray, cranial portion of anterior cerebral artery and vascular territories in the 2nd slice increased significantly (p < 0.05-0.001), but vise versa in other ROIs. Region to cerebellum ratios also showed regional difference similar to RIs.

• Applied Chemistry for Engineering
• /
• v.21 no.5
• /
• pp.522-526
• /
• 2010

Heat storage application techniques can be categorized into the sensible heat storage and the latent heat storage according to the method of heat storage. Heat storage is the way of saving remaining heat when heating and cooling loads are light, and then using it when the heating and cooling loads are heavy. Latent heat storage is defined as the method of saving heat by using substances which have high potential heat when phase change is in the range of a certain temperature and when heat storage space is small, compared to those of sensible heat storage and it is possible that absorption and emission of heat at a certain temperature. This study is conducted to save energy when either air-conditioning or heating is operated in a building. We have tried to find out the essential properties of matter and the optimum mixing rate about cement and gypsum for building materials, which have been widely used for proper phase change materials (PCM), when thermal environment property is applied. So we obtained the result of the cooling delay effect about 19% with heat storage mortar containing 3 wt% of PCM.