Review of Studies Related to Pedagogical Content Knowledge in the Context of Science Teacher Education: Turkish Case

As a review study, the present study was carried out in order to introduce PCK construct to researchers and evaluate which aspects of PCK were studied in our country, and, finally, make recommendations in light of the analysis of the studies for further research. For this purpose, ERIC database, YOK (Higher Education Council) database were searched by using "Pedagogical Content Knowledge" as keyword. Moreover, journals published in Turkey and which are possible to be reached electronically were searched using the same keyword. 28 studies in the science education context were analyzed by means of standards obtained from the related literature. Results showed that large part of the studies were conducted with pre-service teachers as case studies. Moreover, PCK was studied in terms of its components rather than as a whole. In addition to that, participant teachers and pre-service teachers have some shortcomings regarding to PCK, pedagogical knowledge, and subject matter knowledge. Findings will hopefully provide some insight for researchers since shortages of the related literature will be determined by this study

Dehydroisomerization of n-butane over Cr/SiO2

The catalytic activity and selectivity of CrOx/SiO2 for the dehydroisomerization of n-butane were studied at 550 degrees C and 1 atm. Influence of chromia concentration and chromia precursor on the oxidation state, activity and selectivity were investigated. The catalysts were characterized by X-ray diffraction (XRD), TGA and temperatures programmed reduction (TPR). The isomerization activity linearly increased with increasing acidity and Cr loading. The addition of chromium precursors in complex form decreased the initial activity in dehydroisomerization of n-butane and but increased the selectivity of butenes. Catalyst, which had the highest acidity and lowest crystallite size, was the most active in isomerization reaction. The highest selectivity and yield of butenes achieved was 92% and 5.5%, respectively. (C) 2008 Elsevier B.V. All rights reserved

Spectral characterization and antimicrobial activity of 2-(5-chloro/nitro-1H-benzimidazol-2-yl)-4-bromo/nitro-Phenols and their zinc(II) complexes

2-(5-Chloro/nitro-1H-benzimidazol-2-yl)-4-bromo/nitro-phenols (HL(x); x=1-4) and their complexes with zinc(II)nitrate have been synthesized and characterized. In the tetrahedral mononuclear complexes, the ligands are bidentate, via the imine nitrogen and the phenolate oxygen atoms. The structures of the complexes were confirmed on the basis of elemental analysis, molar conductivity, TGA, FT-IR. NMR, mass and UV-vis spectroscopy. The optimized geometry of the complexes was derived from theoretical calculation in DGauss/DFT level on CACHE program. From theoretical calculations it was found that bromo derivatives of the ligands (HL(1) and HL(3)) have higher stability than the other ligands and similarly, their Zn(II) complexes have higher stability than the other complexes. The antimicrobial activities of the compounds were evaluated using the disk diffusion method against six bacteria and Candida albicans. All of the complexes exhibited selective antibacterial activity on Staphylococcus epidermidis. HL(3) and [Zn(L(1))(2)]center dot H(2)O are more active than Ciprofloxazin and, [Zn(L(2))(2)] has antibacterial activity as potent as Ciprofloxazin against S. epidermidis. (c) 2010 Elsevier B.V. All rights reserved

Mediated Effects of Technology Competencies and Experiences on Relations among Attitudes Towards Technology Use, Technology Ownership, and Self Efficacy about Technological Pedagogical Content Knowledge

This study examined the relations of preservice science teachers' attitudes towards technology use, technology ownership, technology competencies, and experiences to their self-efficacy beliefs about technological pedagogical content knowledge (TPACK). The present study also investigated interrelations among preservice teachers' attitudes towards technology use, technology ownership, technology competencies, and experiences. The participants of study were 665 elementary preservice science teachers (467 females, 198 males) from 7 colleges in Turkey. The proposed model based on educational technology literature was tested using structural equation modeling. The model testing results revealed that preservice teachers' technology competencies and experiences mediated the relation of technology ownership to their TPACK self efficacy beliefs. The direct relation of their possession of technology to their TPACK self efficacy beliefs was insignificant while the indirect relation through their technology competencies and experiences was significant. The results also indicated there were significant direct effects of preservice teachers' attitudes towards technology use, technology competencies, and experiences on their TPACK self efficacy beliefs

Synthesis, Spectral and Theoretical Characterization of 5,6-Dichloro/Dimethyl-2-(2´,3´/2´,4´/2´,5´/3´,4´/3´,5´-Dimethoxyphenyl)-1H-Benzimidazoles

5,6-Dichloro/dimethyl-2-(2´,3´/2´,4´/2´,5´/3´,4´/3´,5´-dimethoxyphenyl)-1H-benzimidazoles were synthesized and characterized by using analytical data, FT-IR, FT-Raman, NMR, ESI-MS and fl uorescence spectroscopy. The optimized molecular geometry, zero point energy, dipole moment, ESE, band gap and charge distributions were calculated by Gaussian 09 using Density Functional Theory (DFT, RB3LYP) with 6-31++G(d,p) basis set. According to the calculations, the molecules have structures with various torsion angles between the benzimidazole and benzene rings from 9.7º to 47.8º. The calculated energy values with ZPE correction and DFT show that the methyl derivatives are more stable than the chloro forms. 3´,4´-Dimethoxy derivatives have higher decomposition points in comparison with the other compounds in series. The chlorine atoms of 5,6-dichloro-2- (2´,3´/2´,4´/2´,5´/3´,4´/3´,5´-dimethoxyphenyl)-1H-benzimidazoles are positively charged whereas the C5 and C6 carbon atoms are negatively charged due to the attached chlorine atoms, in virtue of the electron withdrawing characteristic of the imidazole part of the benzimidazole ring. Also, some calculated prominent bond lengths and bond angles were discussed