• Membrane Journal
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• v.18 no.4
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• pp.274-281
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• 2008

Covalent-crosslinked sulfonated poly(arylene ether sulfone) (SPAES) copolymers were synthesized copolymerization technique and additionally crosslinked with divinylbenzene (DVB). To optimize the reaction condition, a concentration of crosslinking agent and a reaction time were varied in the ranges of $30{\sim}90\;v/v%$ and $30{\sim}720\;min$. The properties of the crosslinked membranes were investigated by SEM, TGA and the measurement of proton conductivity. It was found that the proton conductivity of crosslinked membranes decreased depending on a degree of crosslinking while water uptake and methanol permeability reduced.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.444-450
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• 2011

A novel method that utilizes poly(5-methyl-2-thiozyl methacrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid-co-divinylbenzene) [MTMAAm/AMPS/DVB] as a solid-phase extractant was developed for simultaneous preconcentration of trace Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Ni(II), Pb(II), and Zn(II) prior to the measurement by flame atomic absorpiton spectrometry (FAAS). Experimental conditions for effective adsorption of the metal ions were optimized using column procedures. The optimum pH value for the simultaneously separation of the metal ions on the new adsorbent was 2.5. Effects of concentration and volume of elution solution, sample flow rate, sample volume and interfering ions on the recovery of the analytes were investigated. A high preconcentration factor, 100, and low relative standard deviation values, $\leq$1.5% (n = 10), were obtained. The detection limits (${\mu}gL^{-1}$) based on the 3s criterion were 0.18 for Cd(II), 0.11 for Co(II), 0.07 for Cr(III), 0.12 for Cu(II), 0.18 for Fe(III), 0.67 for Mn(II), 0.13 for Ni(II), 0.06 for Pb(II), and 0.09 for Zn(II). The validation of the procedure was performed by the analysis of two certified reference materials. The presented method was applied to the determination of the analytes in various environmental samples with satisfactory results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.11
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• pp.1248-1255
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• 2012

LDPC decoder architectures are generally classified into serial, parallel and partially parallel architectures. Conventional method of LDPC decoding in general give rise to a large number of computation operations, mass power consumption, and decoding delay. It is necessary to reduce the iteration numbers and computation operations without performance degradation. This paper studies horizontal shuffle scheduling(HSS) algorithm and self-correction normalized min-sum(SC-NMS) algorithm. In the result, number of iteration is half than conventional algorithm and performance is almost same between sum-product(SP) and SC-NMS. Finally, This paper implements high-speed LDPC decoder based on FPGA. Decoding throughput is 816 Mbps.

• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.695-701
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• 2005

Efficient method was established for analysis of sulfur-containing compounds, including dimethyl disulfide, dimethyl trisulfide, 3-methyl thiophene, allyl mercaptan, 2-methyl-3-furanthiol, and methional. Sulfur-containing compounds were extracted through solid phase microextraction (SPME) or static headspace extraction (SH), and quantified using gas chromatograph equipped with pulsed flame photometric detector. All sulfur compounds, except ally mercaptan, showed higher detection response when dissolved in hexane than in dichloromethane. Linear range was $10^2-10^4$. Dimethyl trisulfide showed lowest limit of detection (LOD) value of 15.2 ppt, and methional highest of 70.5 ppb. Highest extraction efficiency for sulfur-containing compounds, particularly polar and small molecular weight compounds, was observed in 75mm carboxen/polydimethylsiloxane fiber, followed by 65mm polydimethylsiloxane/divinylbenzene and 100mm polydimethylsiloxane. Compared to SPME, less sulfur-containing compounds could be analyzed by SH, mainly due to its low extraction efficiency, although lower amount of artifacts were formed during sample preparation.