• Asian-Australasian Journal of Animal Sciences
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• v.31 no.11
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• pp.1773-1780
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• 2018

Objective: This study was to evaluate effects of mixed plant oils (identified as mixed oil 1 [MO1] and mixed oil 2 [MO2]) on performance, serum composition, viscera percentages, meat quality, and fatty acid deposition of broilers. Methods: A total of 126 one-day-old Arbor Acres male broiler chicks (weighing $44.91{\pm}0.92g$) were randomly allocated to 1 of 3 treatments with 7 replicate pens per treatment (6 broilers per pen). Dietary treatments included a corn-soybean basal diet supplemented with 3% soybean oil (CTR), basal diet with 3% MO1 (a mixture of 15% corn oil, 10% coconut oil, 15% linseed oil, 20% palm oil, 15% peanut oil and 25% soybean oil; MO1), or basal diet with 3% MO2 (a combination of 50% MO1 and 50% extruded corn; MO2). The trial consisted of phase 1 (d 1 to 21) and phase 2 (d 22 to 42). Results: Compared to CTR, broilers fed MO (MO1 or MO2) had greater (p<0.05) average daily gain in phase 1, 2, and overall (d 1 to 42), redness in thigh muscle, concentrations of serum glucose, serum albumin, saturated fatty acids (SFA) and n-6/n-3 polyunsaturated fatty acids (PUFA) ratio in breast muscle, while these broilers also showed lower ($p{\leq}0.05$) drip loss and concentrations of C18:3n-3 and PUFA/SFA ratio in breast muscle. Broilers fed MO2 had higher (p<0.05) liver percentage, while broilers fed MO1 had lower ($p{\leq}0.05$) feed conversion ratio in phase 1 and increased (p<0.05) contents of C18:2n-6, C20:5n-3, C22:6n-3, and n-3 PUFA in breast muscle compared to CTR. Conclusion: Mixed plant oils had positive effects on performance, serum parameters, meat quality, liver percentage and fatty acid deposition in broilers, which indicates they can be used as better dietary energy feedstocks than soybean oil alone.

• Environmental Engineering Research
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• v.11 no.4
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• pp.173-180
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• 2006

Autotrophic nitrogen removal and its microbial community from a laboratory scale upflow anaerobic sludge bed reactor were characterized with dynamic behavior of nitrogen removal and sequencing result of molecular technique (DNA extraction, PCR and amplification of 16S rDNA), respectively. In the experiment treating inorganic wastewater, the anaerobic granular sludge from a full-scale UASB reactor treating industrial wastewater was inoculated as seed biomass. The operating results revealed that an addition of hydroxylamine would result in lithoautotrophic ammonium oxidation to nitrite/nitrate, and also hydrazine would play an important role for the success of sustainable nitrogen removal process. Total N and ammonium removal of 48% and 92% was observed, corresponding to nitrogen conversion of 0.023 g N/L-d. The reddish brown-colored granular sludge with a diameter of $1{\sim}2\;mm$ was observed at the lower part of sludge bed. The microbial characterization suggests that an anoxic ammonium oxidizer and an anoxic denitrifying autotrophic nitrifier contribute mainly to the nitrogen removal in the reactor. The results revealed the feasibility on development of high performance lithoautotrophic nitrogen removal process with its microbial granulation.

• Journal of Hydrogen and New Energy
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• v.34 no.1
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• pp.69-76
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• 2023

An experimental study was conducted on a 4-stroke direct injection diesel engine to examine the combustion and emission characteristics of 1-octanol/diesel fuel blends. The concentration of 1-octanol in the fuel blends was 10%, 30%, and 50% by volume. Experiments were conducted by varying the engine torque from 6 Nm to 12 Nm at the same engine speed of 2,700 rpm. Results showed that the fuel conversion efficiency increased as the 1-octanol proportion increased under most experimental conditions. However, the brake specific fuel consumption increased due to the relatively low lower heating value of 1-octanol. The smoke opacity and the concentrations of NO_x and CO emissions generally decreased with brake mean effective pressure as the 1-octanol proportion increased. On the other hand, the unburned hydrocarbon concentration increased with an ascending ratio of 1-octanol.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.4
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• pp.113-117
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• 2016

Recently, hydrogen is regarded as important energy in the future, because it is clean and renewable. The photoelectrochemical (PEC) system, which produce hydrogen using water splitting by solar energy, is one of the most promising energy systems because it has abundant energy sources and good theoretical efficiency. GaN has recently been regarded as suitable photoelectrode that could be used to split water to generate hydrogen without extra bias because its band edge position include water redox potential ($V_{redox}=1.23$ vs. SHE). GaN also shows considerable corrosion resistance in aqueous solutions and it is possible to control its properties, such as structure, band gap, and catalyst characteristics, in order to improve solar energy conversion efficiency. But, even if the band edge position of GaN make PEC reaction facilitate without bias, the overpotential of oxygen evolution reaction could reduce the efficiency of system. One of the ways to decrease overpotential is introduction of co-catalyst on photoelectrode. In this paper, we will investigate the effect of manganese dioxide ($MnO_2$) as a co-catalyst. $MnO_2$ particles were dispersed on GaN photoelectrode by spincoater and analyzed properties of the PEC system using potentiostat (PARSTAT4000). After coating $MnO_2$, the flat-band potential ($V_{fb}$) and the onset voltage ($V_{onset}$) were moved negatively by 0.195 V and 0.116 V, respectively. The photocurrent density increased on $MnO_2$ coated sample and time dependence was also improved. These results showed $MnO_2$ has an effect as a co-catalyst and it would enhance the efficiency of overall PEC system.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.3
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• pp.416-423
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• 2020

Objective: This study examined the effects of divergence in residual feed intake (RFI) on expression profiles of key genes related to lipid transport in the liver and duodenal epithelium and their associations with feed efficiency traits in meat-type ducks. Methods: A total of 1,000 male ducks with similar body weight (1,042.1±87.2 g) were used in this study, and their individual RFI was calculated from 21 to 42 d of age. Finally, the 10 highest RFI (HRFI) and 10 lowest RFI (LRFI) ducks were chosen for examining the expression of key genes related to lipid transport in the liver and duodenal epithelium using quantitative polymerase chain reaction. Results: In the liver, expression levels of albumin (ALB), CD36 molecule (CD36), fatty acid hydroxylase domain containing 2 (FAXDC2), and choline kinase alpha (CHKA) were significantly higher in LRFI ducks than in HRFI ducks (p<0.01); negative correlations (p<0.05) between expression levels of ALB, CD36, FAXDC2, and CHKA and RFI were detected in the liver. Additionally, ALB expression was strongly positively correlated (p<0.05) with CD36, FAXDC2, CHKA, and apolipoprotein H (APOH) expression in the liver. In duodenal epithelium, we found that mRNA levels of ALB, CD36, FAXDC2, and APOH were significantly higher in LRFI ducks than in HRFI ducks (p<0.01); RFI was strongly negatively correlated (p<0.05) with ALB, FAXDC2, and APOH expression, while ALB expression was strongly positively correlated with APOH expression (p<0.01) in duodenal epithelium. Furthermore, expression levels of both ALB and FAXDC2 genes were significantly associated with feed conversion ratio and RFI in both liver and duodenal epithelium (p<0.05). Conclusion: Our findings therefore suggest that ALB and FAXDC2 genes might be used as potential gene markers designed to improve feed efficiency in future meat-type duck breeding programs.

• Journal of Power System Engineering
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• v.12 no.5
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• pp.27-33
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• 2008

Natural gas has been considered one of the most promising alternative fuels for transportation because of its abundance as well as its ability to reduce regulated pollutants. We measured emission characteristics of nanoparticles from lean burn H/D(Heavy-Duty) CNG (Compressed Natural Gas) engine equipped with oxidation catalysts. The experiments were carried out to measure the emission and engine performance according to the ESC test cycle. The CO and THC conversion efficiencies on the best catalyst in the ESC test cycle achieved about 91 % and 83 %, respectively. From the measurement by the SMPS, the number of nanoparticles emitted from H/D CNG engine is reduced by about 99 % which is more than that of 2.5 L diesel engine. The particle number concentrations of H/D CNG engine were almost nanoparticles. Nanoparticles smaller than 30 nm emitted from the H/D CNG engine and diesel engine equipped with a CDPF(Catalyzed Diesel Particulate Filter) were quite similar. However, the particles bigger than 30nm from the CNG engine were smaller than the particles from diesel engine equipped with a CDPF. The higher the CNG engine load, the lower the particle number from engine-out, but it increased slightly at full load.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.12
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• pp.1087-1093
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• 2010

Autotrophic denitrification is known as an effective and economical alternative for heterotrophic denitrification using external carbon sources such as methanol. In this study, we evaluated design and operation parameters for a sulfur denitrification reactor (SDR) treating high strength nitrogen wastewater. The SDR was filled with spherical sulfur media in connected to a pilot-scale nutrient removal process (daily flow rate, $Q=18\;m^3/d$) using moving spongy media. Total nitrogen (TN) concentration of the final effluent was below the 7.0 mg TN/L because nitrate was additionally removed through autotrophic denitrificationin without adding alkalinity (initial alkalinity was $169.4{\pm}20.8\;mg$ $CaCO_3$/L). During the test period, 60~80% of nitrogen in the influent was removed even in low temperature (below $15^{\circ}C$). The alkalinity consumption for nitrate removal in SDR was $4.09{\pm}1.29$ g $CaCO_3/g$ ${NO_3}^-$-N, and the residual alkalinity of influent of SDR was higher than that of theoretical requirements for full conversion of nitrate. The consumption of sulfur was 943.8 g S/d and it was 2.4 times higher than theoretical value (400.1 g S/d) due to abrasion and loss of sulfur media in backwash, etc.

• Journal of the Korean Electrochemical Society
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• v.6 no.1
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• pp.59-64
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• 2003

We fabricated mixed ionic-electronic conducting membranes, $CH_4\;Using\;{0.7}Sr_{0.3}Ga_{0.6}Fe_{0.4}O_{3-\delta}$, by solid state reaction method for solid oxide fuel cell. The membranes consisted of single perovskite phase and exhibited high relative density, $>95\%$. We coated $La_{0.6}Sr_{0.4}CoO_{3-\delta}$ layer using screen printing method in order to improve surface reactivity of the $La_{0.7}Sr_{0.3}Ga_{0.6}Fe_{0.4}O_{3-\delta}$. As a result, the oxygen permeation flux of the coated $La_{0.7}Sr_{0.3}Ga_{0.6}Fe_{0.4}O_{3-\delta}$ showed higher value, $0.5ml/min{\cdot}cm^2\;at\;950^{\circ}C$ than the uncoated one. Higher oxygen permeation was observed in the porously coated Lao $La_{0.7}Sr_{0.3}Ga_{0.6}Fe_{0.4}O_{3-\delta}$membranes with larger grain sizes. Syngas, $CO+H_2$, was successfully obtained from methane gas, $CH_4$, using the $La_{0.6}Sr_{0.4}CoO_{3-\delta}$ coated $La_{0.7}Sr_{0.3}Ga_{0.6}Fe_{0.4}O_{3-\delta}$, with over $40\%\;of\;CH_4$ conversion and syngas yield. $La_{0.7}Sr_{0.3}Ga_{0.6}Fe_{0.4}O_{3-\delta}$ membrane was stable even when it was exposed to the reducing environment, methane, for 600 hrs at $950^{\circ}C$.

• BMB Reports
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• v.46 no.12
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• pp.575-581
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• 2013

Lipid droplet (LD) is a cellular organelle that stores neutral lipids as a source of energy and carbon. However, recent research has emerged that the organelle is involved in lipid synthesis, transportation, and metabolism, as well as mediating cellular protein storage and degradation. With the exception of multi-cellular organisms, some unicellular microorganisms have been observed to contain LDs. The organelle has been isolated and characterized from numerous organisms. Triacylglycerol (TAG) accumulation in LDs can be in excess of 50% of the dry weight in some microorganisms, and a maximum of 87% in some instances. These microorganisms include eukaryotes such as yeast and green algae as well as prokaryotes such as bacteria. Some organisms obtain carbon from $CO_2$ via photosynthesis, while the majority utilizes carbon from various types of biomass. Therefore, high TAG content generated by utilizing waste or cheap biomass, coupled with an efficient conversion rate, present these organisms as bio-tech 'factories' to produce biodiesel. This review summarizes LD research in these organisms and provides useful information for further LD biological research and microorganism biodiesel development.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.33-36
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• 2014

Gasification of biomass produces syngas containing CO, $H_2$ and/or $CH_4$, which can then be converted into energy or value-added fuels. One of key issues for efficient gasification is to minimize tar concentration in the syngas for use in a final conversion device such as gas engine. This study investigated the decomposition of primary tar by catalytic cracking using char as catalyst, of which the feature can be integrated into a fixed bed gasifier design. The pyrolysis vapor containing tar from pyrolysis of wood at $500^{\circ}C$ was passed through a reactor filled with or without char at $800^{\circ}C$ for a residence time of 1, 3 or 5 sec. Then, the condensable vapor (water and tar) and gases were analyzed for the yields and elemental composition. Four types of char particles with different microscopic surface area and pore size distribution: wood, paddy straw, palm kernel shell and activated carbon. The results were analyzed for the mass and carbon yields of tar and the composition of product gases to conclude the effects of char types and residence time.