Exploring perceived cognitive load in learning programming via Scratch

The purpose of this study is to investigate the perceived cognitive load and its effects on the academic performance in Scratch-based programming. The four main concepts of programming (sequences, operators, conditions and loop) were delivered in the instructional package. Participants were 12 sixth-grade students enrolled at a public secondary school. The results from quantitative and qualitative instruments indicated that students’ perceived cognitive loads were close to each other among four programming concepts. The attractive interface of Scratch was somewhat useful but some parts of the interface were problematic for achieving the programming tasks. This study concludes with suggestions for Scratch practitioners and researchers to pay attention to the sources of cognitive load effects

Synthesis and antimicrobial activity of new Schiff bases having the -SiOR group (R = CH 3 or CH 2 CH 3 ), and their transition metal complexes

Two new Schiff base ligands containing -SiOCH 3 or -SiOCH 2 CH 3 groups, 4-{[(3-trimethoxysilanepropyl)imino]methyl} benzene-1,3-diol (1) Hmsb and 4-{[(3-triethoxysilanepropyl)imino]methyl}benzene- 1,3-diol (5) Hesb, have been synthesized by the reaction of 2,4- dihydroxybenzaldehyde with 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane. Six new transition metal [Cu II , Ni II and Co II complexes of these Schiff Base ligands were prepared. The complexes are formed by coordination of N, O atoms of the ligands. Their structures were confirmed by elemental analyses, 1 H nmr, i.r. and u.v.-vis. spectral data. The analytical data shows that the metal-to-ligand ratio in the Schiff Base complexes contains silane in 1:2. In addition, the antimicrobial activity of (1) Hmsb and (5) Hesb Schiff ligands, and their [M(msb) 2 ] and [M(esb) 2 ] type coordination compounds, were investigated. © Springer 2005

New soluble coordination chain polymers of nickel(II) and copper(II) ions and their biological activity

A new tetraoxime ligand, (2E, 3E, 9E, 10E)-1, 4, 8, 11- tetraazacyclotetradecane-2, 3, 9, 10-tetrone tetraoxime has been prepared by the template condensation of 1,3-propanediamine and cyanogen-di-N-oxide, obtained by treating (E, E)-dichloroglyoxime in CH 2 Cl 2 with Na 2 CO 3 at -10 °C. The coordination chain polymers {[(pnngH 2 ) 2 Ni] n (5) and [(pncgH 2 ) 2 Cu] n ( 6 )} of two transition metal ions, [Ni(II) and Cu(II)] with the vic-dioxime ligand have been prepared. The oxime ligand acts as a polydentate ligand bending through nitrogen atoms in the presence of a base, as do most of the vic-dioximes. In the complexes, the chloride ions coordinate to the nickel and copper ions. The structures of these novel vic-dioxime compounds are proposed on the basis of the elemental analyses, molar conductance data, i.r., and U.v.-visible are presented. Elemental analyses indicate a ligand metal ratio of 1:1 in the coordination polymers. Conductivity measurements have shown that mono- and polynuclear complexes are non-electrolytes. In addition, anti-microbial activities of the compounds have been investigated. © Springer 2005.We thank the Research Fund of Kahramanmara·s Süt-c¸ ü İmam University for financial support