• Journal of the Korean Society of Safety
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• v.21 no.1 s.73
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• pp.59-64
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• 2006

In this study, adsorption characteristics of PCBs on granular activated carbon were experimentally investigated in a batch reactor and in a fixed bed reactor. Granular activated carbon removed above 98.4% of initial concentration, 1000mg/L, of PCBs. It was estabilished that the adsorption equilibrium of PCBs on granular activated carbon was more successfully fitted by Freundlich isotherm equation in the concentration range from 1 to 1000mg/L. Because Freundlich parameter, ${\beta}$ is 0.346, removall treatment of PCBs by activated carbon accounts for the fact that toxicity reduction can be achieved through this process. Appearance time of breakthrough curve is faster with the increase flow rate and inflow concentration of liquid. The utility of granular activated carbon is enhanced with the increase of bed height and with the decrease of inflow rate.

• Journal of the Korean Institute of Gas
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• v.8 no.4 s.25
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• pp.42-49
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• 2004

We study on and simulate the behavior of one-step fixed bed reactor which synthesize DiMethylEther(DME) from Methane. At last, we know that reaction is decreased in case of excess and no cooling because the temperature of reactor is decreased or increased seriously. Also, we study on optimizing the reactor so that we know the optimized operation condition according to cooling effect, space velocity of reactant and temperature of reactant, etc.

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.2
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• pp.191-196
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• 2003

Silkworm body and rearing seat disinfection is an integral part of effective silkworm rearing as it prevents the spread of various diseases through secondary contamination in the rearing bed. Many bed disinfectants are recommended by various research institutes in India. In the present study, eight bed disinfectants viz., Vijetha, Labex, Resham Jyothi, Sanjeevini, Suraksha, Reshamkeet Oushadh, Dithane M45 and Captan recommended by various Sericultural Research Institutions in the country against the spread of common diseases of silkworm were tested to determine their comparative efficacy. For the study, all the treatment batches were introduced with fixed number of specific diseased larvae so as to maintain a constant source of pathogen in the bed and then followed by treatment with respective bed disinfectants. Percent mortality/infection due to each disease was recorded to determine efficacy of bed disinfectant treatment against respective disease. The results show that all the bed disinfectants tested have considerable efficacy against the spread of various diseases in the rearing bed. However, Vijetha was distinctly superior in its efficacy against all four major diseases of silkworm. The study emphasize the role of bed disinfectants in silkworm rearing and the fact that they should be judiciously selected based on the efficacy of the bed disinfectant and the type of disease prevalent in a particular season and area.

• Journal of Environmental Science International
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• v.21 no.3
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• pp.305-312
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• 2012

This work is to study the variations of adsorption characteristics of binary vapor according to packing system of double-layer bed by fixed bed experiment. Breakthrough curves of single and binary vapor composed of acetone and benzene on single-layer and double-layer adsorption bed composed of activated carbon (AC) and silica-aluminar (SA) were compared. Adsorptions of binary vapor on double-layer bed were influenced by the differences of surface area between adsorbents as well as the polarity difference between adsorbent and adsorbate. The roll-up phenomenon of acetone vapor was happened by replacement with competing adsorption between acetone vapor and benzene vapor on AC bed, but it was not happened on SA bed because acetone vapor and benzene vapor had less difference in affinity with SA bed. The breakthrough times of acetone vapor and benzene vapor on AC/SA double-layer bed were three times and 1.4 times larger respectively than on SA/AC double-layer bed, the differences of breakthrough times were relatively larger than the equilibrium adsorption capacities according to packing system of double-layer bed.

• 한국연소학회:학술대회논문집
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• 2013.06a
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• pp.21-23
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• 2013

Various solid particle materials are treated in the industrial processes including fixed-beds or moving grate beds, and modeling approaches have been widely applied to the processes to predict and evaluate their performance. For this study, the modeling approach was applied to iron ore sintering process with various improvement measures. Based on the previous modeling approach, the changes and effects of the improvement measures were discussed at the point of controlling the combustion environment in the bed.

• Journal of Wetlands Research
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• v.13 no.3
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• pp.677-686
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• 2011

This study proposes a formula to calculate length of river bed protection through experimental research and an experimental plant has been installed to investigate the parameters which influence the length of scouring in the river after overflowing the weir. Through hydraulic experiments, the critical velocity, difference of water level between upstream and downstream and height of weir have been selected as independent variables. And new formula to calculate a length of river bed protection is suggested as the result of this study in the consideration of complex weir that consists of movable and fixed weir. The new formula is verified through additional experiments. Results of this study can be used for weir structures' construction and maintenance plans.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.3
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• pp.335-341
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• 1998

In this paper, we present a real time implementation of CS-ACELP(Conjugate Structure Algebraic Code Excited Linear Prediction) speech coder. ITU-T has standardized the CS-ACELP algorithm as G.729. Areal-time implementation of CS-ACELP speech coder algorithm is achieved using 16 bit fixed-point DSP chip. To implement in fixed-point DSP Chip, integer simulation of CS-ACELP algorithm is used. Furthermore. input/output function and communication function included in CS-ACELP speech coder is described. We develope CS-ACELP speech coder in DSP evaluation board and evaluate in IMT-2000 Test-bed.

• Current Research on Agriculture and Life Sciences
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• v.15
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• pp.83-91
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• 1997

Phenolic acids are regarded as harmful materials in food and environment science. But recently, regarded as useful materials by their characteristics which bind metal ions and have pharmaceutical effect. It was necessary to remove or recover phenolic acids from solutIon containing phenolic acids. Continuous fixed-bed adsorption was adapted in order to separate phenolic acids from diluted solution and the breakthrough curve was predicted by nonlinear curve fitting method. The larger bed length showed the longer breakpoint time and the slow mass transfer coefficient. Ferulic acid among the phenolic acids was passed through the breakpoint first and the second and. third were p-coumaric acid and gallic acid. These orders were caused by not only ionic strength between adsrobent and adsorbate but also molecular weights.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.4
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• pp.355-363
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• 2014

Thermal shock or overheating of WGS catalyst for SEWGS system during hydrogen pre-treatment can cause reactivity decay of the catalyst. To select appropriate pre-treatment condition, temperature profiles of catalyst bed (or outside fluidized particle bed of bed insert) during pre-treatment were measured and then CO conversions of those catalysts during WGS reaction were also measured and compared. Drastic overheating of catalyst took place when we reduce catalyst at fixed bed condition and these catalysts showed low CO conversion during WGS reaction. On the contrary, there was no overheating of catalyst at fluidized bed condition not only physical mixing case but also bed insert case. Spring type bed insert showed acceptable CO conversion even at low WGS content. Consequently, feasibility of high CO conversion without decay of reactivity of catalyst and holding the WGS catalyst inside the SEWGS reactor as tablet shape were confirmed using spring type bed insert.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2016.05a
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• pp.223-224
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• 2016