• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.172-172
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• 2011

Anaerobic digestion(AD) has successfully been used for many applications that have conclusively demonstrated its ability to recycle biogenic wastes. AD has been successfully applied in industrial waste water treatment, stabilsation of sewage sludge, landfill management and recycling of biowaste and agricultural wastes as manure, energy crops. During AD, i.e. organic materials are decomposed by anaerobic forming bacteria and fina1ly converted to excellent fertilizer and biogas which is primarily composed of methane(CH4) and carbon dioxide(CO2) with smaller amounts of hydrogen sulfide(H2S) and ammonia(NH3), trace gases such as hydrogen(H2), nitrogen(N2), carbon monoxide(CO), oxygen(O2) and contain dust particles and siloxanes. The production and utilisation of biogas has several environmental advantages such as i)a renewable energy source, ii)reduction the release of methane to the atomsphere, iii)use as a substitute for fossil fuels. In utilisation of biogas, most of biogas produced from small scale plant e.g. farm-scale AD plant are used to provide as energy source for cooking and lighting, in most of the industrialised countries for energy recovery, environmental and safety reasons are used in combined heat and power(CHP) engines or as a supplement to natural. In particular, biogas to use as vehicle fuel or for grid injection there different biogas treatment steps are necessary, it is important to have a high energy content in biogas with biogas purification and upgrading. The energy content of biogas is in direct proportion to the methane content and by removing trace gases and carbon dioxide in the purification and upgrading process the energy content of biogas in increased. The process of purification and upgrading biogas generates new possibilities for its use since it can then replace natural gas, which is used extensively in many countries, However, those technologies add to the costs of biogas production. It is important to have an optimized purification and upgrading process in terms of low energy consumption and high efficiency giving high methane content in the upgraded gas. A number of technologies for purification and upgrading of biogas have been developed to use as a vehicle fuel or grid injection during the passed twenty years, and several technologies exist today and they are continually being improved. The biomethane which is produced from the purification and the upgrading process of biogas has gained increased attention due to rising oil and natural gas prices and increasing targets for renewable fuel quotes in many countries. New plants are continually being built and the number of biomethane plants was around 100 in 2009.

• Transactions of the Korean hydrogen and new energy society
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• v.11 no.3
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• pp.119-125
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• 2000

To improve the photochemical energy conversion efficiency and the stability of CdS particulate film electrode which is used to produce hydrogen from the aqueous $H_2S$ solution photoelectrochemically, surface treatment of this film was carried out using $TiCl_4$ solution. CdS particles for preparation of the films were synthesized by precipitation reaction of $Cd({NO_3})_2{\cdot}9H_2O$ and $Na_2S{\cdot}4H_2O$. Then, the CdS sol was hydrothermally treated for 12hr in an autoclave with the variation of treatment temperature to control the crystalline phase of particles. CdS film electrode was thus prepared by annealing at $400^{\circ}C$ for 12hr of the wet-film cast at room temperature, and subsequently surface treated with $TiCl_4$ solution. The electrodes were characterized using XRD, SEM, and the photocurrent meter. The photocurrents of Cds film electrodes prepared with surface treatment were up to two times higher than the electrodes without surface treatment, indicating about $4.0mA/cm^2$. Hydrogen production rate in a continuous flow system using photoelectrochemical or photochemical cells prepared with surface treatment also increased in proportion to the increase of photocurrents.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.3
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• pp.230-237
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• 2007

Titania nanotube(TiNT) and CdS sol were synthesized by hydrothermal reaction under strongly basic condition and by precipitation reaction of $Cd(N0_3)_2$ and $Na_2S$ aqueous solutions, respectively. After preparing a series of CdS-TiNT composite films on $F:SnO_2$ conducting glass with variation of the mole ratio (r) of TiNT/(CdS+TiNT), their visible light absorption, photocatalytic activities for hydrogen production, and the photocurrent generation were examined. In general, this CdS-TiNT series showed lower photocatalytic activities and photocurrent generation under Xe light irradiation compared to their counterparts, i.e., CdS-$TiO_2$ particulate series. It appeared that TiNTs are not so effective photocatalyic material in spite of their larger specific surface areas compared to $TiO_2$ nanoparticles, because they indicate a poor crystallinity and less intimate interaction or contact with CdS particles owing to the tubular morphology and an easy agglomeration among themselves.

• Economic and Environmental Geology
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• v.41 no.3
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• pp.335-344
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• 2008

The acid rock drainage (ARD) production potential of rock was assessed for a tunnel construction area, Kimhae and the damage reduction strategy was discussed based on the ARD risk evaluation. The geology of the studied area consisted of Mesozoic quartz porphyry, sandstone, tuff and granite. Sulfides occurred as a disseminated type in quartz porphyry and granite, and a vein type in sandstone. Quartz porphyry and sandstone with a high content of sulfide were classified as a potentially ARD forming rock. The drainage originated from those rocks may acidify and contaminate the surrounding area during the tunnel construction. Therefore, the drainage should be treated before it is discharged. A slope stability problem due to the ARD was also expected and the coating technology was recommended for the reduction of ARD generation before the application of supplementary work for enhancing slope stability such as shotcrete and anchor. From the ARD risk analysis, those rocks should not be used as aggregate and be used as bank fill material with the system for the minimum contact with rain water and ground-water.

• Journal of Animal Science and Technology
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• v.52 no.3
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• pp.199-204
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• 2010

The objective of this study was to evaluate the effect of the different types and levels of prebiotics on intestinal microflora and fermentation products in the in vitro fermentation model. The prebiotcs used in this study were IMO (iso-malto oligosaccharide), CI (partially digested chicory-inulin), RA (raffinose) and CD (cyclodextrin). Experimental diet for growing pigs was predigested by digestive enzymes and this hydrolyzed diet was mixed with buffer solution containing 5% fresh swine feces. Then, the mixture was fermented with or without prebiotics at the concentrations of 0.5 and 1.0% for 24 h. Samples were taken at 24 h, and viable count of micoflora, gas, pH, volatile organic compounds and short-chain fatty acids were determined. The viable count of Enterobacteriaceae was significantly decreased (p<0.001) in all treatments added with prebiotics in comparison to control without prebiotics. However, the increase of lactic acid bacteria was observed in the prebiotics treatment. Gas production increased as the level of prebiotics increased. The pH values in the fermentation fluid decreased in a dose-dependent manner with increasing the concentration of prebiotics. The fermentation with prebiotics resulted in the reduction of malodorous compounds such as ammonia, hydrogen sulfide, indole and skatole. The increase in short-chain fatty acid (SCFA) production was observed in the treatments with prebiotics. In conclusion, the results of this study demonstrated that the fermentation with prebiotics was effective in reducing the formation of malodorous compounds and increasing lactic acid bacteria and SCFA. These effects depended on the concentration of prebiotics. Moreover, further study is needed to determine whether the in vitro efficacy on the reduction of malodorous compounds and increase of SCFA would also be observed in animals.

• Food Science and Preservation
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• v.22 no.1
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• pp.108-118
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• 2015

To raise the added value of the fruits of Cudrania tricuspidata, Cudrania tricuspidata vinegar was produced and examined for its fermentation conditions. Forty nine acetic acid bacteria with resistance against acetic acid, ethanol, and sulfide as high acetic acid producers were isolated from fermented foods and identified as Acetobacter indonesiensis, A. cerevisiae, A. orientalis, A. tropicalis, A. fabarum, A. pasteurianus, and A. syzygii based on the results of the analysis of the 16S rRNA gene sequences. Among them, two GRAS strains, A. pasteurianus SCMA5 and SCMA6, were finally selected for the production of acetic acid. Optimal vinegar productions were obtained from the medium containing 40% (v/v) fruit juice of Cudrania tricuspidata and 5% (v/v) ethanol at $25^{\circ}C$ for 72 hr. The sensory panel preferred the vinegar fermented with the SCMA06 to that with the SCM05 strain. The radical scavenger capacity of DPPH was 53% higher than that of the control in the vinegar fermented with the SCMA06 strain. The ${\alpha}$-glucosidase inhibitor activity as an index of the antidiabetic drug showed 91% inhibition, which is higher than that of acabose. This study will be helpful for the scale-up production of vinegar with the fruit of Cudrania tricuspidata.

• Journal of Animal Environmental Science
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• v.15 no.3
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• pp.217-224
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• 2009

The pig slurry is one of important fertilizer source for production of crops in recent years, but it has many controversial points of utilization such as offensive odor, lack of spread equipment and farmland possession, respectively. This study was carried out in order to remove water pollutants and malodor of pig slurry using biofiltration system. The biofiltration system consists of pig slurry separator, mixing shift and attached blade for sawdust or ricehull, air injection nozzle and outlet for pig slurry and sawdust or ricehull. The characteristics pH, $BOD_5$ (Biochemical Oxygen Demand), $COD_{Mn}$ (Chemical Oxygen Demand), SS (Suspended Solid), T-N (Total Nitrogen), T-P (Total Phosphorus) of the untreated pig slurry used in this study were 7.2, 34,450, 24,604, 71,000, 4,194, $1,631\;ml/{\ell}$, respectively. The $NH_3$ (Ammonia) and $H_2S$(Hydrogen Sulfide) concentration were 70.0, 9.6 ppm, respectively. The initial total microorganisms of pig slurry were $5.0{\times}10^3\;cfu/ml$, and Salmonella, Bacillus were $5.8{\times}10^2$, $1.1{\times}10^3\;cfu/ml$, respectively. The filtration system was very effective on removal of water pollutants of pig slurry. The removal efficiency of the offensive odor of ammonia and hydrogen sulfide in sawdust was higher than those of ricehull. The total microorganisms and bacillus of pig slurry are on the increase by sawdust and ricehull, but Salmonella showed a tendency to decrease in number after that time. Accordingly, the filtration system was very effective to produce a good quality pig slurry.

• Korean Journal of Poultry Science
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• v.37 no.2
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• pp.145-150
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• 2010

This study was conducted to evaluate effects of dietary Agariemycetes on egg quality and fecal noxious gas concentration in laying hens. A total of two hundred forty laying hens were randomly allocated to four treatments with five replicates of twelve chicks per pen. The experiment lasted 42 days with a 7-day adjustment period. Dietary treatments were as follows: 1) CON (basal diet), 2) A1 (basal diet + Agariemycetes 0.1%), 3) A3 (basal diet + Agariemycetes 0.3%) and 4) A5 (basal diet + Agariemycetes 0.5%). There was no significant difference in egg production and egg weight between CON and Agariemycetes treatments. During the second week of the experiment, eggshell breaking strength was higher in A3 and A5 treatments than that in CON treatment (P<0.05). Besides, eggshell breaking strength in P5 treatment was higher when compared with that in CON treatment (P<0.05) in the sixth week. During the second week of the experiment, eggshell thickness was higher in Agariemycetes treatments than CON treatment (P<0.05). Also, A5 treatment was higher than other treatments in the fourth week of the experiment (P<0.05). At the end of the second week, yolk color unit in A5 treatment was lower compared with CON treatment (P<0.05). During the fourth week of the experiment, CON treatment was higher than A3 treatment (P<0.05). During the second week of the experiment, Haugh unit in A3 treatment was greater than that in CON treatment (P<0.05). At the end of six weeks, Haugh unit in CON treatment was lower than other treatments (P<0.05). Fecal ammonia and hydrogen sulfide were increased in Agariemycetes treatments when compared with CON treatment (P<0.05). Compared with CON and A5 treatments, fecal mercaptans was higher than in other treatments in first of the experiment (P<0.05). In conclusion, this study indicated that the addition of Agariemycetes in the diet improved the egg quality and decreased the feacal noxious gas concentration in laying hens.

• Journal of Animal Science and Technology
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• v.48 no.3
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• pp.453-466
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• 2006

To comply with stricter regulations provoked by increasing odor nuisance, it is imperative to practice effective odor control for sustainable livestock production. This study was conducted to assess odor and odorous compounds emitted from liquid animal manure with different treatment methods such as Fresh Manure(without treatment, FM), Anaerobic Digestion(AD) and Thermophilic Aerobic Digestion(TAD) and their application to soil. Air samples were collected at the headspace of liquid manure, upland and paddy soil, and analyzed for odor intensity and offensiveness using an olfactometry; odor concentration index using odor analyser; nitrogen-containing compound such as ammonia(NH3) using fluorescence method; and sulfur containing compounds such as hydrogen sulfide(H2S), methyl mercaptan(MeSH), dimethyl sulfide(DMS) and dimethyl disulfide(DMDS) using gas chromatography-pulsed flame photometric detector, respectively. Odor intensity, offensiveness and concentration index from TAD liquid manure was statistically lower than those from FM and AD(p<0.01). Mean concentrations of H2S, MeSH, DMS, DMDS and NH3 were 65.93ppb, 18.55ppb, 5.26ppb, 0.33ppb and 10.57ppm for liquid manure with AD; and 5.15ppb, 0.97ppb, 0.80ppb, 0.56ppb and 1.34ppm for liquid manure with TAD, respectively. More than 60% of malodorous compounds related to nitrogen and sulfur were removed by heterotrophic microorganisms during TAD treatment. When liquid manure was applied onto upland and paddy soil, NH3 removal efficiencies ranged from 51 to 94% and 22 to 91% for AD and TAD liquid manure, respectively. The above results show that liquid manure with TAD is superior to AD and FM with respect to the odor reduction and odor problem caused by land applied liquid manure is directly related to the degree of odor generated by the manure treatment method.

• Korean Journal of Soil Science and Fertilizer
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• v.4 no.1
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• pp.13-19
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• 1971

In order to establish the method of improving ill drained paddy soil where the accumulation of absorption inhibitor is worried in the earlier stages of rice growth, proper soil is selected and an field experiment is designed having treatments such as lime materials, none sulfate fertilizers, boron and straw etc. The data of yield and plant analysis in different stages of rice growth is eveluated and discussed to obtain following summaries. (1) Significant yield increase was made by the treatment of lime materials such as slacked lime or wollastonite powder, materials inhibiting the activity of microorganisms such as boron and of none sulfate fertilizers lacking inhibitor producing sources. (2) The crop scientifice causes of decreasing yield are the decreasing the number of panicles per hill, grains per panicle and the weight of grains. (3) The plant nutritional causes of decreasing yield are the lowering of nitrogen content throughout the life, phosphate content since young premodia formation stage of plant and the decreased content of magnesium, calcium and silicate in straw at harvesting stage. (4) The causes of lowering the content of various elements in rice plant grown in ill drained paddy soil are suggested as root damage by producing and accumulating absorption inhibitors such as organic acids and hydrogen sulfide etc, from the following observed facts; (a) In young premodia formation stage, attaining to the maximum production and accumulation of absorption inhibitor, the phosphate accumulation in plant was smaller in the phosphate plots than without phosphate plots and much higher in the neutralized plots by adding lime materials. (b) In the plots of straw addition, the potassium content in plant at the young premodia formation stage is very low probabley due to root damage by absorption inhibitor produced from the process of straw decomposition but higher at the stage of harvesting probably due to the immetabolic negative absorption of damaged roots. (c) The effect of boron, known as the inhibitor of microorganism activity to decompose organic matter, is apparent. (d) The effect of nonsulfate fertilizer treatment, having no source of producing inhibitor such as hydrogen sulfide, was significant. (e) All the yield components, decided around the young premodia formation stage attaining to the maximum inhibitor concentration in soil and minimum root activity, are significantly decreased.