2 resultados para Let me in

em Brock University, Canada


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This qualitative inquiry used case study methodology to explore the change processes of 3 primary-grade teachers throughout their participation in 7 -month professional learning initiative focused on reading assessment and instruction. Participants took part in semimonthly inquiry-based professional learning community sessions, as well as concurrent individualized classroom-based literacy coaching. Each participant's experiences were first analyzed as a single case study, followed by cross-case analyses. While their patterns of professional growth differed, findings documented how all participants altered their understandings of the roles and relevancy of individual components of reading instruction (e.g., comprehension, decoding) and instructional approaches to scaffold students' growth (e.g., levelled text, strategy instruction), and experienced some form of conceptual change. Factors identified as affecting their change processes included; motivation, professional knowledge, professional beliefs (self-efficacy and theoretical orientation), resources (e.g., time, support), differentiated professional learning with associated goal-setting, and uncontrollable influences, with the affect of each factor compounded by interaction with the others. Comparison of participants' experiences to the Cognitive-Affective Model of Conceptual Change (CAMCC) and the Interconnected Model of Teacher Professional Growth (IMTPG) demonstrated the applicability of using both conceptual models, with the IMTPG providing macrolevel insights over time and the CAMCC microlevel insights at each change intervaL Recommendations include the provision of differentiated teacher professional learning opportunities, as well as research documenting the effects of teacher mentorship programs and the professional growth of teacher educators. ii

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The preparation and characterization of two families of building blocks for molecule-based magnetic and conducting materials are described in three projects. In the first project the synthesis and characterization of three bis-imine ligands LI - L3 is reported. Coordination of LI to a series of metal salts afforded the five novel coordination complexes Sn(L4)C4 (I), [Mn(L4)(u-CI)(CI)(EtOH)h (II), [CU(L4)(u-sal) h(CI04)2 (sal = salicylaldehyde anion) (III), [Fe(Ls)2]CI (IV) and [Fe(LI)h(u-O) (V). All complexes have been structurally and magnetically characterized. X-ray diffraction studies revealed that, upon coordination to Lewis acidic metal salts, the imine bonds of LI are susceptible to nucleophilic attack. As a consequence, the coordination complexes (I) - (IV) contain either the cyclised ligand L4 or hydrolysed ligand Ls. In contrast, the dimeric Fe3+ complex (V) comprises two intact ligand LI molecules. In. this complex, the ligand chelates two Fe(III) centres in a bis-bidentate manner through the lone pairs of a phenoxy oxygen and an imine nitrogen atom. Magnetic studies of complexes (II-V) indicate that the dominant interactions between neighbouring metal centres in all of the complexes are antiferromagnetic. In the second project the synthesis and characterization two families of TTF donors, namely the cyano aryl compounds (VI) - (XI) and the his-aryl TTF derivatives (XII) - (XIV) are reported. The crystal structures of compounds (VI), (VII), (IX) and (XII) exhibit regular stacks comprising of neutral donors. The UV -Vis spectra of compounds (VI) - (XIV) present an leT band, indicative of the transfer of electron density from the TTF donors to the aryl acceptor molecules. Chemical oxidation of donors (VI), (VII), (IX) and (XII) with iodine afforded a series of CT salts that where possible have been characterized by single crystal X -ray diffraction. Structural studies showed that the radical cations in these salts are organized in stacks comprising of dimers of oxidized TTF donors. All four salts behave as semiconductors, displaying room temperature conductivities ranging from 1.852 x 10-7 to 9.620 X 10-3 Scm-I. A second series of CT salts were successfully prepared via the technique of electrocrystallization. Following this methodology, single crystals of two CT salts were obtained. The single crystal X-ray structures of both salts are isostructural, displaying stacks formed by trimers of oxidized donors. Variable temperature conductivity measurements carried out on this series of CT salts reveal they also are semiconductors with conductivities ranging from 2.94 x 10-7 to 1.960 X 10-3 S em-I at room temperature. In the third project the synthesis and characterization of a series of MII(hfac)2 coordination complexes of donor ligand (XII) where M2+ = Co2+, Cu2+, Ni2+ and Zn2+ are reported. These complexes crystallize in a head-to-tail arrangement of TTF donor and bipyridine moieties, placing the metal centres and hfac ligands are located outside the stacks. Magnetic studies of the complexes (XV) - (XVIII) indicate that the bulky hfac ligands prevent neighbouring metal centres from assembling in close proximity, and thus they are magnetically isolated.