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Ian Moodie 대한언어학회 2018 언어학 Vol.26 No.4
Moodie, Ian. (2018). Comparing the practices of experienced and novice Korean English teachers in relation to curricular aims for English education. The Linguistic Association of Korea Journal, 26(4), 125-150. This study contributes towards understanding the classroom practices of Korean public school English teachers by introducing and applying an observation protocol which analyzes how teachers’ pedagogic activities relate to curricular recommendations for English education such as having student-centered, meaning-focused, and communicative English classes. The study included three classes each from two experienced and two novice primary school English teachers. The analysis showed that the experienced teachers’ classes were much more communicative and student-centered than the novice teachers’ classes were (e.g., 40% to 64% of class time spent on communicative activities versus 8% to 25% for the novice teachers), but that both novice and experienced teachers focused mostly on language forms rather than meaning in their lessons, and that none of the teachers used any task-based activities. The study concludes with implications and recommendations for future research based on these results.
Effects of catalysts on structural and adsorptive properties of iron oxide-silica nanocomposites
Cătălin Ianăși,Paula Ianăși (b. Svera),Adina Negrea,Mihaela Ciopec,Oleksandr I. Ivankov,Alexander I. Kuklin,László Almásy,Ana-Maria Putz 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.2
Iron oxide-silica nanocomposites were prepared by sol-gel method using ammonia (NH3), acetic acid (CH3COOH) and hydrochloric acid (HCl) catalysts to generate different pH values for the reaction conditions. As starting precursors, for the silica, respectively, for the iron oxide, tetraethylorthosilicate (TEOS) and iron-III-acetylacetonate were used. The physico-chemical characterization of the materials revealed that the sample obtained with HCl catalyst displays the largest surface area (300m2/g), the most compact network structure, highest surface roughness, biggest crystallite size (14 nm), magnetization (7 emu/g) and superparamagnetic behavior. These materials were tested for adsorption of Cr6+ and Zn2+ from aqueous solution. Sample M-HCl presented the highest surface area and was further used for adsorption of metal ions. Kinetic, thermodynamic and equilibrium adsorption measurements studies were made for Cr6+ and Zn2+. To establish the material behavior from a thermodynamic point of view, temperature and contact time of adsorption process, activation energy, free energy, of standard enthalpy and entropy were calculated. The kinetic behavior was modelled by pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic models and the adsorption characteristics were determined by modelling the experimental data with Langmuir, Freundlich and Sips isotherms.
Removal of cadmium from aqueous solutions using inorganic porous nanocomposites
Cătălin Ianăşi,Mirela Picioruş,Roxana Nicola,Mihaela Ciopec,Adina Negrea,Daniel Nižňanský,Adél Len,László Almásy,Ana-Maria Putz 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.5
The present paper reports a one-pot synthesis of magnetic nanocomposites samples through acid catalyzed sol-gel method. Fe(III) acetylacetonate was used as precursor of the iron oxide phase: tetraethylortosilicate for the silica phase and polyvinyl alcohol (PVA, molecular mass 49000) as pore former. Different concentrations of Fe2O3 in composites matrices were prepared and studied ranging from 0% to 20%. All reactions took place in one pot at room temperature; the materials were subsequently heat treated at 300 oC, to ensure the crystallinity for the iron oxide having spinel structure, forming nanoparticles confined in the silica matrix. The materials were characterized using X-ray diffraction, small-angle neutron scattering, FT-IR spectroscopy, nitrogen adsorption, Mössbauer spectroscopy and magnetization measurements. The maximum value of room temperature saturation magnetization of ~54 emu/g and 0.11 kOe coercive field was achieved for the magnetic nanocomposite sample with 20% Fe2O3. The highest surface area of 680m2/g was obtained for the sample with 10% Fe2O3. The potential applicability of the obtained materials was studied for adsorption performance for cadmium in aqueous solutions. The Langmuir isotherm model described well the adsorption data, indicating monolayer adsorption of Cd(II) on the heterogeneous composite surface.
Ultrasonic preparation of mesoporous silica using pyridinium ionic liquid
László Almásy,Ana-Maria Putz,Adél Len,Catalin Ianăşi,Cecilia Savii 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.3
Mesoporous silica matrices have been prepared via classic acid catalyzed and sono-catalyzed sol-gel routes. Tetramethoxysilan (TMOS) and methyl-trimethoxysilane (MTMS) were used as silica precursors, and N-butyl-3-methylpyridinium tetrafluoroborate ([bmPy][BF4]) was employed as co-solvent and pore template. The ionic liquid (IL) to silica mole ratio was varied between 0.007 and 0.07. Nitrogen adsorption-desorption and small-angle neutron scattering measurements were used to characterize the obtained materials. The ionic liquid played the role of catalyst that affected the formation of the primary xerogel particles, and changed the porosity of the materials. Ultrasound treatment resulted in microstructure change on the level of the colloid particle aggregates. In comparison with IL containing xerogels, the IL containing sonogels show increased pore diameter, bigger pore volumes and diminished surface areas.
Ian Reid,michelle ricard 한국펄프·종이공학회 1999 한국펄프종이학회 기타 간행물 Vol.- No.-
Treatment with the enzyme pectinase has been reported to lower the cationic demand of thermo mechanical pulp (TMP) bleached with alkaline peroxide in the laboratory. We have extended this discovery to bleached TMP produced industrially, and shown that commercial enzyme preparations can treat pulp within 15 minutes at the temperature and pH values prevalent in paper mills. About half of the cationic demand in the bleached pulp can be destroyed by pectinase. Dynamic drainage jar experiments<br/> show that the enzyme treatment improves the effectiveness of several cationic polymers to increase retention of fines and filler particles. It does not increase retention in the absence of retention aids or with non-ionic polymers, and does not damage the strength properties of the pulp. Pectinase could be easily incorporated into paper machine stock preparation systems to lower the charges of cationic retention aids needed in furnishes containing peroxide-bleached mechanical pulp.