• Applied Chemistry for Engineering
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• v.16 no.1
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• pp.144-149
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• 2005

Sulfonated poly(ether ether ketone) (SPEEK) was blended with poly(ether sulfone) (PES) at various compositions. To investigate the possibility of using the blend membranes as polymer electrolyte membranes for direct methanol fuel cell, the blend membranes were characterized in terms of methanol permeability, proton conductivity, ion exchange capacity, and water content. Both proton conductivity and methanol permeability of SPEEK were relatively high. As the amount of PES increased, methanol permeability decreased more rapidly compared to proton conductivity. The experimental results indicated that the blend membrane with 40 wt% PES was the best choice in terms of the ratio of proton conductivity to methanol permeability.

• Analytical Science and Technology
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• v.10 no.1
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• pp.60-65
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• 1997

Solvent extraction of alkali metal and alkaline earth metal cations by mono-crown ether(benzo-15-crown-5) and bis-(crown ether)s(ethylenediamine bis(4'-formyl benzo-15-crown-5)) containing benzo-15-crown-5 moieties were investigated with water-chloroform system at $25^{\circ}C$. The order of the extraction equilibrium constants($K_e$) and the complexation constants($K_c$) for the alkali metal and alkaline earth metal cations with mono-crown ether and bis-(crown ether)s were Ca(II)>Na(I)>Sr(II)>K(I)>Mg(II)>Rb(I) and Sr(II)>Ca(II)>K(I)>Rb(I)>Mg(II)>Na(I) respectively. These results were explained in terms of the size effect of metal cation and electron density effect. Also, the bis-(crown ether)s was found to extract metal cations more effectively than the corresponding mono-crown ether.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.31-39
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• 2015

The synergistic solvent extraction of rare earth elements such as europium and yttrium has been investigated by the extractant with crown ether as an additive. Macrocyclic ligand as host-guest compounds form more stable complexes with metal ions which have the similar size of the cavity of crown ether. In our previous study[14] founded that the extraction used fatty acid of the various alkyl chain length. Based on the results of the previous experiment, the synergistic separation effect of two metals investigated that the hexanoic acid had was the worst extraction effect which added a crown ether such as 18-crown-6 ether, 15-crown-5 ether, and 12-crown-4 ether. In this study, the concentrations of hexanoic acid have showed the separation effect, and then the concentrations and kind of crown ether are performed for synergistic extraction at the hexanoic acid concentration of the highest separation effect. As a results, the separation rate is the highest value of 1.72 at 0.05 M hexanoic acid, and 0.002M 15-crown-5 ether is the best value in other concentrations and kind of crown ether, it is about twice of using only hexanoic acid. Moreover, the extraction species of two metals has been founded $MLR_3{\cdot}3RH$ form when added the crown ether.

• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.131-136
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• 2021

EtherCAT is an Ethernet-based fieldbus system standardized in IEC 61158 and SEMI, and widely used in the fields of factory automation, semiconductor equipment and robotics. In this paper, a real-time EtherCAT master is implemented on Linux operating systems and its performances are evaluated. To enhance the real-time capability of mainline Linux kernel, Xenomai is applied as a real-time framework and an open source EtherCAT master stack, Simple Open EtherCAT Master (SOEM), is installed on it. Unlike other studies, the real-time performance of the EtherCAT master is evaluated at the output of the network interface card, so that the evaluation results include all possible effects from the EtherCAT master system. The implemented EtherCAT master can send and receive packets up to 20KHz control frequency with low jitter, even in stressed condition.

• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.26-32
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• 2022

EtherCAT is an Ethernet-based fieldbus system standardized in IEC 61158 and SEMI, and widely used in the fields of factory automation, semiconductor equipment and robotics. In this paper, an EtherCAT master is implemented on an embedded board with Arm based 64-bit quad-core processor and its jitter performance is evaluated at the output of the network interface to include all the effects of the entire system in the results. For the EtherCAT master system, an open source EtherCAT master stack, Simple Open EtherCAT Master (SOEM), is installed on PREEMPT_RT patched Linux operating system for real-time operation. The results show that the jitter performance is comparable to that of Xenomai-based master and the EtherCAT master with two master instances has similar jitter performance to the EtherCAT master with one master instance.

• Macromolecular Research
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• v.11 no.3
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• pp.202-205
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• 2003

The reactive precursors, vinyl ethers, and epoxy-silicones, were synthesized. The vinyl ether monomers were prepared from primary alcohol and ethyl vinyl ether with mercury (II) acetate. The epoxy-functionalized silicones have been achieved by the controlled, rhodium-catalyzed, chemoselective hydrosilation of vinyl ether with siloxanes or silane. It was shown that the hydrosilation proceeds exclusively at the vinyl ether group of alkenyl vinyl ether without participation at the alkenyl group. The photoinduced cationic polymerization of these monomers was studied and found to be all highly reactive.

• IEMEK Journal of Embedded Systems and Applications
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• v.9 no.2
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• pp.117-125
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• 2014

The EtherCAT protocol has become a very promising alternative for real-time industrial application due to its ability to eliminate uncertainties in the Ethernet. However, the extended markup language (XML) for the EtherCAT network system, which is required in the design, lacks systematic development to take advantage of model transformation techniques. This paper focuses on the system development procedure of the EtherCAT-based encoder system using the CANopen over EtherCAT (CoE) protocol. UML modeling is being adapted to design for XML of EtherCAT-based encoder system. To this purpose, this paper analyzes the object dictionary (OD) of a commercial encoder and CANopen over EtherCAT. A UML diagram is then designed based on the analysis, and XML is generated through the designed UML diagram. Finally, an experimental test_bed for the EtherCAT-based encoder system is implemented and its performance is compared with a commercial encoder.

• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.56-61
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• 2011

Alkyl vinyl ethers such as methyl vinyl ether, propyl vinyl ether, isopropyl vinyl ether, butyl vinyl ether and isobutyl vinyl ether are usually used as industrial solvents and chemical intermediates in the chemical or pharmaceutical industry. Recently, they are popularly used as raw materials for polymer electrolyte membrane fuel cells and as cellulose dyeing assistants. However, very few investigations about process design and operation data were reported for alkyl vinyl ether compounds and there are no data for propyl vinyl ether(PVE) systems as far as we know. In this work, the isothermal VLE data are reported at 333.15 K for the ternary systems of {PVE + ethanol + benzene} by using headspace gas chromatography(HSGC) and these VLE data were correlated using Wilson, NRTL and UNIQUAC equations. The excess volumes($V^E$) and deviations in molar refractivity(${\Delta}R$) data are also reported for the sub binary systems {PVE + ethanol}, {ethanol + benzene} and {PVE + benzene} at 303.15 K. These data were correlated with Redlich-Kister equation. In addition, isoclines of $V^E$ and DR for ternary system {PVE + ethanol + benzene} were also calculated from Radojkovi equation.

• KSBB Journal
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• v.15 no.2
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• pp.162-166
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• 2000

This study was pe바ormed to observe the effects of Platycodon grandiflorum A. DC (3 years) extracts on the bronchus d diseases bacteria(Mycobacterium sp., K. pneumoniae, F. nucleatum, S. aureus, C. diphtheriae, S. pygogenes and N N. gonorrhoeae) and fungi(A. fumigatus). Platycodon grandiflorum A. DC was extracted by ethanol, water, ethyl ether and p petroleum ether. The extraction rates of Platycodon grandiflorum A. DC were identified as 71.8%, 100%, 15.4% and 14.1% i in each extract solution. Each extract solution was injected into culture media with several concentrations and then the b bacteria cell growth was investigated during 32 hours. As a result, the antimicrobial activities of extracts from ethyl ether and p petroleum ether were excellent. Among several concentrations, the percentage of bacteria cell growth inhibitions were observed to be from 0.06% to 0.14%. The rates of antimicrobial activities were over 70%. The degree of cell growth | inhibition of each bacteria was appeared in the order of ethyl ether > petroleum ether > water > ethanol.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.4
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• pp.1367-1372
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• 2010

Copoly(ether-ether-ester)s having flexible side chain were synthesized by polycondensation. Intrinsic viscosities of polymers were between 0.42 and 0.78dl/g in tetrachloroethane. The polymer structures were investigated by $^1H$-NMR and FT-IR, and thermal and liquid crystalline properties of polymers were measured by DSC, TGA, POM and XRD. As results of investigations, synthetic copolymers exhibited lower melting temperature than homopolymers. When the biphenylene units contents in copolymer were more than 60 mol %, nematic mesophase was observed, and the mesophase of synthetic polymers was dependent upon biphenylene content.