• Clean Technology
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• v.13 no.1 s.36
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• pp.54-63
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• 2007

Even traces of CO in the hydrogen-rich feed gas to proton exchange membrane fuel cells (PEMFC) poison the platinum anode electrode and dramatically decrease the power output. In this work, a variety of catalytic materials consisting of $Cu/Ce_xZr_{1-x}O_2$, (x = 0.0-1.0) were synthesised, characterized and tested for CO oxidation and preferential oxidation of CO (PROX). These catalysts prepared by hydrothermal and deposition-precipitation methods. The catalysts were characterized by XRD, XRF, SEM, BET, $N_2O$ titration and oxygen storage capacity (OSC) measurement. The effects of composition of the support and degree of excess oxygen were investigated fur activity and $CO_2$ selectivity with different temperatures. The composition of the support markedly influenced the PROX activity. Among the various $Cu/Ce_xZr_{1-x}O_2$ catalysts having different composition, $Cu/Ce_{0.9}Zr_{0.1}O_2$ and $Cu/Ce_{0.7}Zr_{0.3}O_2$ showed the highest activities (>99%) and selectivities (ca.50%) in the temperature range of $150{\sim}160^{\circ}C$. It was found that by using of $Ce_xZr_{1-x}O_2$ mixed oxide support which possesses a high oxygen storage capacity, oxidation-reduction activity of Cu-based catalyst was improved, which resulted in the increase of catalytic activity and selectivity of CO oxidation in excess $H_2$ environments.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.551-558
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• 2003

This study was conducted to investigate the effect of dietary wormwood powder (Artemisia montana Pampan; WP) supplementation on growing performance and fecal noxious gas emission in weanling pigs. One hundred and twelve pigs were alloted into four treatments and offered for 4 weeks one of the diets supplemented with 0% (control), 0.5% (0.5), 1.0% (1.0) and 2.0% (2.0) WP. Each treatments has four replicate with 7 pigs per replicate. ADG, ADFI and F/G were improved by 1.0 and 2.0 WP supplementation during 0d${\sim}$14d feeding. Feed intake of 1.0 WP diet was higher (P<0.05) than any other diet during 15d${\sim}$28d feeding. But there were no differences among the other treatments in the weight gain and feed conversion. During the whole feeding period, daily weight gain and feed intake of pigs fed 1.0 and 2.0 treatments were higher than those of pigs fed control and 0.5 diet. DM digestibility was significantly (P<0.05) higher in weanling pigs fed 0.5, 1.0 and 2.0 WP than that of the control. The protein digestibility was significantly improved in 1.0 WP treatment and the phosphorus digestibility was improved in 2.0 WP treatment. Excretion of nitrogen and phosphorus was significantly (P<0.05) decreased by 2.0 treatment than control. Emission of fecal ammonia after 48 hours storage in vinyl bag dramatically decreased by all the treatments except control. However, there was no statistical difference in fecal hydrogen sulfide emission among treatments. In conclusion, this study suggested that the dietary 1.0${\sim}$2.0 supplementation of WP can improve productivity of pigs decrease fecal $NH_3$ and $H_2S$ gas emission.

• Korean Chemical Engineering Research
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• v.56 no.6
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• pp.871-877
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• 2018

Storing the surplus energy from renewable energy resource is one of the challenges related to intermittent and fluctuating nature of renewable energy electricity production. $CO_2$ methanation is well known reaction that as a renewable energy storage system. $CO_2$ methanation requires a catalyst to be active at relatively low temperatures ($250-500^{\circ}C$) and selectivity towards methane. In this study, the catalytic performance test was conducted using a pressurized bubbling fluidized bed reactor (Diameter: 0.025 m and Height: 0.35 m) with $Ni/{\gamma}-Al_2O_3$ (Ni70%, and ${\gamma}-Al_2O_3$30%) catalyst. The range of the reaction conditions were $H_2/CO_2$ mole ratio range of 4.0-6.0, temperature of $300-420^{\circ}C$, pressure of 1-9 bar, and gas velocity ($U_0/U_{mf}$) of 1-5. As the $H_2/CO_2$ mole ratio, temperature and pressure increased, $CO_2$ conversion increases at the experimental temperature range. However, $CO_2$ conversion decreases with increasing gas velocity due to poor mixing characteristics in the fluidized bed. The maximum $CO_2$ conversion of 99.6% was obtained with the operating condition as follows; $H_2/CO_2$ ratio of 5, temperature of $400^{\circ}C$, pressure of 9 bar, and $U_0/U_{mf}$ of 1.4-3.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.550-554
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• 2001

'Fuyu' persimmon fruits (Diospyros kaki Thunb.) were seal-packaged in $60{\mu}m$ polyethylene (PE) film bags with various $O_2$ and $CO_2$ combinations (0% $O_2$+5% $CO_2$, 2% $O_2$+5% $CO_2$, 2% $O_2$+8% $CO_2$, 5% $O_2$+5% $CO_2$, 5% $O_2$+10% $CO_2$), and in vacuum and air. They were then stored at $-0.5^{\circ}C$ for 95 days. Changes in fruit weight, firmness, soluble solids, Hunter L and a values, $CO_2$ concentrations, and marketability were investigated at 20-day intervals. A combination of 2% $O_2$ and 5% $CO_2$ as well as the vacuum treatment were effective in maintaining firmness, soluble solids, marketability, and Hunter a value of 'Fuyu' fruits. On the other hand, the treatment of 2% $O_2$ combined with 8% $CO_2$ and vacuum treatment were effective in maintaining fresh weight and Hunter L and a values. The highest marketable quality was maintained when the fruits were vacuum-sealed, although fruits softened severely in the area where two fruits contacted with each other.

• Fire Science and Engineering
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• v.34 no.2
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• pp.147-155
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• 2020

This paper presents a study on the development of a fire extinguishing agent and extinguishing system for an energy storage system (ESS) fire. The fire extinguishing agent designed to extinguish an ESS fire is a highly permeable fire extinguisher that reduces the surface tension and viscosity while bringing about cooling action. This is the main extinguishing effect of this type of wetting agent, which displays the characteristics of fire extinguishing agents used for penetrating the battery cells inside the ESS module. For the fire extinguishing system, a local application system was designed to suppress fire on a rack-by-rack basis. A 360° rotating nozzle was inserted into the rear hall of the ESS module, and general nozzles were installed in the rack to maximize the fire extinguishing effect. The fire extinguishing agent was strongly discharged by virtue of the gas release pressure. Experiments on fire suppression performance with ESS module 1 unit and module 3 units showed that all visible flames were extinguished in 8 s and 9 s, respectively, by the fire extinguishing agent. In addition, based on confirming reignition for 600 s after the fire extinguishing agent was exhausted, it was confirmed that the ESS fire was completely extinguished without reignition in all fire suppression performance experiments.

• Journal of Environmental Health Sciences
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• v.46 no.4
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• pp.423-432
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• 2020

Objectives: In this study, we analyzed the current state of delivery containers and packages and established handling guidelines to safely transport delivery containers and packages for use in research, testing, and examination reagents. Methods: Handling guidelines were revised in such categories as maintenance of the handling facilities, storage, loading and unloading, containers and packages, transportation, etc. In addition, we analyzed the current state of domestic sales for hazardous chemicals used for research, testing, and examination reagents, and investigated the handling guidelines related to delivery transportation in the USA, EU, and Japan by chemical property. Results: There are 6,160 companies selling hazardous chemicals. Among them, the 476 companies selling reagents for use in research, testing, and examination were investigated. Total amounts handled reached 425,000 tons, contributing to 0.2% of the total. For delivery transportation, internal containers and packaging was specified for chemical properties as follows: within 1 L for flammable gas, within 5 L for flammable liquid, and within 18 L for others. In addition, the maximum size of the outer package was set within 130 cm for total length, width, and height, and no dimension of the packaging could exceed 60 cm. Sixty-four hazardous chemicals with explosiveness or acute inhalation toxicity were prohibited for delivery transportation. Conclusion: Specified handling guidelines for inner and outer containers as well as packaging were regulated for delivery transportation of hazardous chemicals used for reagents. In addition, 64 hazardous chemicals were prohibited for delivery transportation. These are designed to prevent transportation accidents involving hazardous chemicals for reagents and thus protect the safety and health of transporters who handle hazardous chemicals.

• Journal of Environmental Impact Assessment
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• v.26 no.4
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• pp.217-226
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• 2017

Although the effects of climate change are universal, Small Island Developing States (SIDS) are considered to be most vulnerable. SIDS heavily rely on imported oil and fossil fuels for electricity generation and transportation, which makes them economically vulnerable and exposed to fluctuating oil price. Among the reasons SIDS highly depend on diesel fuel is due to the dispersed population living in remote islands which means, providing electricity through on on-grid system is difficult. Fiji as one of the SIDS, has actively promoted renewable sourced energy through a national plan to mitigate the impacts of climate change. In order to determine how feasible implementing a renewable energy (RE) system will be in Fiji, this study chose a remote island called Mavuva Island to test application of a hybrid RE system using HOMER. A combination of energy storage system (ESS), solar photovoltaic (PV) and diesel generator turns out to be the most cost effective and optimal configuration, resulting in effective greenhouse gas reduction for the given region.

• Food Science and Preservation
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• v.12 no.6
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• pp.534-539
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• 2005

Effects of grapefruit seed extract and Ag ion solution on the keeping quality and shelf life of mungbean sprouts were investigated in terms of weight loss, gas composition, hardness, color, ascorbic acid content, and viable cell counts during storage. Packages with $30\;{\mu}m$ polypropylene(PP) film was applied for mungbean sprouts dipped in Ag ion solution, 50 ppm and 100 ppm GFSE, 50 ppm and 100 ppm GFSE in Ag ion solution and stored $5^{\circ}C$. Totally weight loss exceeded $1\%$ and no visible signs of shrivelling of mungbean sprouts were observed. GFSE in Ag ion solution treatment, resulting in mungbean sprouts of better visual quality, weight loss, color, ascorbic acid as compared to the control without dipping. A shelf life of 6 days was achieved with 100 ppm GFSE in Ag ion solution treatment.

• Journal of the Korean Society for Nondestructive Testing
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• v.35 no.1
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• pp.46-51
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• 2015

Stainless steel is a popular structural materials for liquid-hydrogen storage containers and piping components for transporting high-temperature fluids because of its superior material properties such as high strength and high corrosion resistance at elevated temperatures. In general, tungsten inert gas (TIG) arc welding is used for bonding stainless steel. However, it is often reported that the thermal fatigue cracks or initial defects in stainless steel after welding decreases the reliability of the material. The objective of this paper is to clarify the characteristics of ultrasonic guided wave propagation in relation to a change in the initial crack length in the welding zone of stainless steel. For this purpose, three specimens with different artificial defects of 5 mm, 10 mm, and 20 mm in stainless steel welds were prepared. By considering the thickness of s stainless steel pipe, special attention was given to both the L(0,1) mode and L(0,2) mode in this study. It was clearly found that the L(0,2) mode was more sensitive to defects than the L(0,1) mode. Based on the results of the L(0,1) and L(0,2) mode analyses, the magnitude ratio of the two modes was more effective than studying each mode when evaluating defects near the welded zone of stainless steel because of its linear relationship with the length of the artificial defect.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.1
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• pp.65-78
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• 2007

The pollutants (Rn, CH, CO, HS, radioactive gas from radiolysis) were generated from the process of construction and operation of underground repository, and after disposal of low-intermediate radioactive waste inside there must be controlled by a ventilation system to distribute them in area where enough air is supported. Therefore, a suitable technical approach is needed especially at an underground repository that is equipped with many entry tunnels, storage tunnels, exhaust-blowing tunnels, and vertical shafts in complicated network form. For the technical approach of such a ventilation system, WIPP (Waste Isolation Pilot Plant) in U. S and SFR (Slutforvar for Reaktorafall) low-intermediate radioactive waste repository in Sweden were selected as the models, for calculating the required air quantity, organizing a ventilation network considering cross section, length, surface roughness of the air passage, and describing a calculation of resistance of each circuit. Based on these procedures, a best suited ventilation system was completed with designing proper capacity of fans and operating plan of vertical shafts. As a result of comparing the two repositories based on the geometry dimensions and ventilation facility equipment operation, more parallel circuit as in WIPP, brought decrease in resistance for entire system leading to reduce of operating costs, and the larger cross-sectional area of the SFR, the greater the percentage of disposal capacity. Accordingly, the mixture of parallel circuit of WIPP repository for reducing resistance and SFR repository formation for enlargement of disposal capacity would be the most rational and efficient ventilation system.