High-Spin and Emissive Molecular Materials: Synthesis and Characterization of New Polynuclear Ni(II) Complexes from the Use of Aromatic Schiff Bases as Bridging Ligands

The employment of the bridging/chelating Schiff bases, N-salicylidene-4-methyl-o-aminophenol (samphH2) and N-naphthalidene-2-amino-5-chlorobenzoic acid (nacbH2), in nickel cluster chemistry has afforded eight polynuclear Ni(II) complexes with new structural motifs, interesting magnetic and optical properties, and unexpected organic ligand transformations. In the present thesis, Chapter 1 deals with all the fundamental aspects of polynuclear metal complexes, molecular magnetism and optics, while research results are reported in Chapters 2 and 3. In the first project (Chapter 2), I investigated the coordination chemistry of the organic chelating/bridging ligand, N-salicylidene-4-methyl-o-aminophenol (samphH2). The general NiII/tBuCO2-/samphH2 reaction system afforded two new tetranuclear NiII clusters, namely [Ni4(samph)4(EtOH)4] (1) and [Ni4(samph)4(DMF)2] (2), with different structural motifs. Complex 1 possessed a cubane core while in complex 2 the four NiII ions were located at the four vertices of a defective dicubane. The nature of the organic solvent was found to be of pivotal importance, leading to compounds with the same nuclearity, but different structural topologies and magnetic properties. The second project, the results of which are summarized in Chapter 3, included the systematic study of a new optically-active Schiff base ligand, N-naphthalidene-2-amino-5-chlorobenzoic acid (nacbH2), in NiII cluster chemistry. Various reactions between NiX2 (X- = inorganic anions) and nacbH2 were performed under basic conditions to yield six new polynuclear NiII complexes, namely (NHEt3)[Ni12(nacb)12(H2O)4](ClO4) (3), (NHEt3)2[Ni5(nacb)4(L)(LH)2(MeOH)] (4), [Ni5(OH)2(nacb)4(DMF)4] (5), [Ni5(OMe)Cl(nacb)4(MeOH)3(MeCN)] (6), (NHEt3)2[Ni6(OH)2(nacb)6(H2O)4] (7), and [Ni6(nacb)6(H2O)3(MeOH)6] (8). The nature of the solvent, the inorganic anion, X-, and the organic base were all found to be of critical importance, leading to products with different structural topologies and nuclearities (i.e., {Ni5}, {Ni6} and {Ni12}). Magnetic studies on all synthesized complexes revealed an overall ferromagnetic behavior for complexes 4 and 8, with the remaining complexes being dominated by antiferromagnetic exchange interactions. In order to assess the optical efficiency of the organic ligand when bound to the metal centers, photoluminescence studies were performed on all synthesized compounds. Complexes 4 and 5 show strong emission in the visible region of the electromagnetic spectrum. Finally, the ligand nacbH2 allowed for some unexpected organic transformations to occur; for instance, the pentanuclear compound 5 comprises both nacb2- groups and a new organic chelate, namely the anion of 5-chloro-2-[(3-hydroxy-4-oxo-1,4-dihydronaphthalen-1-yl)amino]benzoic acid. In the last section of this thesis, an attempt to compare the NiII cluster chemistry of the N-naphthalidene-2-amino-5-chlorobenzoic acid ligand with that of the structurally similar but less bulky, N-salicylidene-2-amino-5-chlorobenzoic acid (sacbH2), was made.

An instructional design model for constructivist learning

The emergent requirements for effective e-learning calls for a paradigm shift for instructional design. Constructivist theory and semiotics offer a sound underpinning to enable such revolutionary change by employing the concepts of Learning Objects. E-learning guidelines adopted by the industry have led successfully to the development of training materials. Inadequacy and deficiency of those methods for Higher Education have been identified in this paper. Based on the best practice in industry and our empirical research, we present an instructional design model with practical templates for constructivist learning.

Organically-functionalised supertetrahedra as building blocks for hybrid materials

The crystal structures of gallium sulfides prepared under solvothermal conditions, using 4-picoline as a solvent, are described. These materials contain [Ga10S16(NC6H7)4]2− clusters, in which the terminal S2− anions have been replaced by covalently bonded 4-picoline molecules. Whilst these phases contain isolated supertetrahedral clusters separated by organic moieties, linkage of such clusters via organic ligands is possible under suitable reaction conditions. These organically-functionalised supertetrahedra could therefore be used to design novel Metal-Organic frameworks (MOFs) in which the normally-encountered metal centers are replaced by supertetrahedral clusters.

EPR of gamma-induced paramagnetic centers in tellurite glasses

Intrinsic paramagnetic responses were observed in the 60TeO(2)-25ZnO-15Na(2)O and 85TeO(2)-15Na(2)O mol% glasses, after gamma-irradiation at room temperature: (1) a shoulder at g(1) = g(parallel to) = 2.02 +/- 0.01 and an estimated g(perpendicular to)similar to 2.0 attributed to tellurium-oxygen hole center (TeOHC); (2) a narrow resonance at g(2)= 1.9960 +/- 0.0005 related to the modifiers and (3) a resolved resonance at g(3) = 1.9700 +/- 0.0005 ascribed to a tellurium electron center (TeEC) of an electron trapped at an oxygen vacancy (V(o)(+)) in a tellurium oxide structural center. It is suggested that the creation of (NBO(-),V(o)(+)) pair follows a mechanism where the modifier oxide molecule actuates as a catalyser. An additional model for the NBO radiolysis produced by the gamma-irradiation is proposed on the basis of the evolution of the g(1), g(2) and g(3) intensities with increasing dose (kGy). Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.

Aminoxyl radicals - pure organic materials with tunable magnetic and sensing properties

Stabile Radikale haben in vielen Bereichen der Chemie, Physik, Biologie und Biomedizin ihren Nutzen unter Beweis gestellt. Gerade im letzten Jahrzehnt erlebte diese Substanzklasse vor allem wegen den Anwendungsmöglichkeiten von Nitroxiden als Red-Ox-Sensoren oder magnetischen Materialen ein erneutes Interesse. Das erste Kapitel beschäftigt sich mit der grundlegenden Theorie zur Entwicklung magnetischer Materialien. Des Weiteren sollen anhand einiger Beispiele Radikale im Komplex mit paragmagnetischen Metallen, Biradikale und Polyradikale beschrieben werden. rnrnIm zweiten Kapitel soll auf die Synthese von Hybrid Fluorophore-Nitrononyl-Nitroxid und Iminonitroxidradiale, sowie ihre Charakterisierung über IR, CV, EPR und Röntgenstrukturanalyse eingegangen werden. Mittels UV/Vis-Spektroskopie soll hierbei eine mögliche Anwendung als Red-Ox-Sensoren festgestellt werden. Hierbei werden über anschließende PL Untersuchungen eben diese Sensoreigenschaften der dargestellten Radikale bestätigt werden. Vielmehr noch soll die Möglichkeit von Pyren-Pyrazol-Nitronyl-Nitroxid als NO-Nachweis erläutert werden.rnrnFortschritte sowohl im Design als auch in der Analyse von magnetischen Materialen auf der Basis von Nitroxiden ist Thema des dritten Kapitels. Über ein klassisches Ullmann-Protokoll wurden verschiedene Nitronyl-Nitroxid und Iminonitroxid Biradiale mit unterschiedlichen π-Brücken zwischen den Radikalzentren synthetisiert. Magnetische Messungen belegen einen relativ starken antiferromagnetischen intramolekularen Austausch für den Großteil der untersuchten Biradikale. Hierbei zeigte sich jedoch eine außergewöhnliche hohe Austausch-Kupplung für 3,3‘-Diazatolandiradikale, die nur über die Existenz von starken intermolekularen Wechselwirkungen beschrieben werden kann. Durch Kombination der Röntgenstrukturanalyse mit DFT Berechnungen konnte im Fall des Tolan verbrückten Diradikals 87c die Intra-Dimer-Kupplung auf Jintra = -8,6 K bestimmt werden. Ein direkter Beweis für eine intermolekulare Anlagerung von Jinter ~- 2K konnte über eine Tieftemperatur AC-Messung von 87c erhalten werden. Bezüglich der magnetischen Messung ist das Nitronyl Biradikal 87c ein vielversprechender Kandidat für einen rein organischen eindimensionalen Quantenmagnet.rnrnAbsicht dieser Untersuchungen ist es zu zeigen, dass über die Kombination verschiedener struktureller Elemente die Sensitivität von Nitroxid basierten Sensoren und die intramolekulare Austauschwechselwirkung in π-konjugierten Spinsystemen so eingestellt werden kann, dass es möglich ist Moleküle mit gezielten Sensor- oder Magneteigenschaften zu entwickeln. rn

Writing center handbooks and travel guidebooks : redesigning instructional texts for multicultural, multilingual, and multinational contexts

In an increasingly interconnected world characterized by the accelerating interplay of cultural, linguistic, and national difference, the ability to negotiate that difference in an equitable and ethical manner is a crucial skill for both individuals and larger social groups. This dissertation, Writing Center Handbooks and Travel Guidebooks: Redesigning Instructional Texts for Multicultural, Multilingual, and Multinational Contexts, considers how instructional texts that ostensibly support the negotiation of difference (i.e., accepting and learning from difference) actually promote the management of difference (i.e., rejecting, assimilating, and erasing difference). As a corrective to this focus on managing difference, chapter two constructs a theoretical framework that facilitates the redesign of handbooks, guidebooks, and similar instructional texts. This framework centers on reflexive design practices and is informed by literacy theory (Gee; New London Group; Street), social learning theory (Wenger), globalization theory (Nederveen Pieterse), and composition theory (Canagarajah; Horner and Trimbur; Lu; Matsuda; Pratt). By implementing reflexive design practices in the redesign of instructional texts, this dissertation argues that instructional texts can promote the negotiation of difference and a multicultural/multilingual sensibility that accounts for twenty-first century linguistic and cultural realities. Informed by the theoretical framework of chapter two, chapters three and four conduct a rhetorical analysis of two forms of instructional text that are representative of the larger genre: writing center coach handbooks and travel guidebooks to Hong Kong. This rhetorical analysis reveals how both forms of text employ rhetorical strategies that uphold dominant monolingual and monocultural assumptions. Alternative rhetorical strategies are then proposed that can be used to redesign these two forms of instructional texts in a manner that aligns with multicultural and multilingual assumptions. These chapters draw on the work of scholars in Writing Center Studies (Boquet and Lerner; Carino; DiPardo; Grimm; North; Severino) and Technical Communication (Barton and Barton; Dilger; Johnson; Kimball; Slack), respectively. Chapter five explores how the redesign of coach handbooks and travel guidebooks proposed in this dissertation can be conceptualized as a political act. Ultimately, this dissertation argues that instructional texts are powerful heuristic tools that can enact social change if they are redesigned to foster the negotiation of difference and to promote multicultural/multilingual world views.

Opportunities in Materials Processing: Metal Casting

Revitalizing manufacturing in the US is a hot topic, and the $1B National Network for Manufacturing Innovation (NNMI) has three new centers focused on metal casting. For structural applications, magnesium casting, structural die-cast alloys, austempered ductile and compacted graphite cast iron, and high strength steel promise dramatic weight reduction and improved performance. Recent experiments and modeling at UAB focus on the development of such new materials and processing routes. A study of the rare earth content in an aerospace magnesium alloy is presented.

Modularity and Integrity Issues in Instructional Engineering

Course materials for e-learning are a special type of information system (IS). Thus, in the development of educational material one may learn from principles, methods, and tools that originated in the Software Engineering (SE) discipline and that are relevant in similar ways in "Instructional Engineering". An important SE principle is mo dularization, which supports properties like reusability and adaptability of code. To foster the adaptability of courseware we present a concept in which learning material is organized as a library of modular course objects. A certain lecturer may customize the courseware according to his specific course requirements. He must consider logical dependencies of and relationship integrity between selected course objects. We discuss integrity issues that have to be regarded for the composition of consistent course materials.

An instructional delivery system for manpower management /

Mode of access: Internet.

Problem identification course. Administrative and instructional guide.

National Highway Traffic Safety Administration, Washington, D.C.

A selected bibliography on hazardous materials control /

Item 499-F-7

Learning for self-regulation: Improving instructional benefits for pupils, teachers, parents, schools, and society at large

Compulsory education laws oblige primary and secondary schools to give each pupil positive encouragement in, for example, social, emotional, cognitive, creative, and ethical respects. This is a fairly smooth process for most pupils, but it is not as easy to achieve with others. A pattern of pupil, home or family, and school variables turns out to be responsible for a long-term process that may lead to a pupil’s dropping out of education. A systemic approach will do much to introduce more clarity into the diagnosis, potential reduction and possible prevention of some persistent educational problems that express themselves in related phenomena, for example low school motivation and achievement; forced underachievement of high ability pupils; concentration of bullying and violent behaviour in and around some types of classes and schools; and drop-out percentages that are relatively constant across time. Such problems have a negative effect on pupils, teachers, parents, schools, and society alike. In this address, I would therefore like to clarify some of the systemic causes and processes that we have identified between specific educational and pupil characteristics. Both theory and practice can assist in developing, implementing, and checking better learning methods and coaching procedures, particularly for pupils at risk. This development approach will take time and require co-ordination, but it will result in much better processes and outcomes than we are used to. First, I will diagnose some systemic aspects of education that do not seem to optimise the learning processes and school careers of some types of pupils in particular. Second, I will specify cognitive, social, motivational, and self-regulative aspects of learning tasks and relate corresponding learning processes to relevant instructional and wider educational contexts. I will elaborate these theoretical notions into an educational design with systemic instructional guidelines and multilevel procedures that may improve learning processes for different types of pupils. Internet-based Information and Communication Technology, or ICT, also plays a major role here. Third, I will report on concrete developments made in prototype research and trials. The development process concerns ICT-based differentiation of learning materials and procedures, and ICT-based strategies to improve pupil development and learning. Fourth, I will focus on the experience gained in primary and secondary educational practice with respect to implementation. We can learn much from such practical experience, in particular about the conditions for developing and implementing the necessary changes in and around schools. Finally, I will propose future research. As I hope to make clear, theory-based development and implementation research can join forces with systemic innovation and differentiated assessment in educational practice, to pave the way for optimal “learning for self-regulation” for pupils, teachers, parents, schools, and society at large.

Learning to Interpret and Generate Instructional Recipes

Thesis (Ph.D.)--University of Washington, 2016-08

Teacher perceived difficulty in implementing differentiated instructional strategies in primary school

This study analyses teacher perceived difficulty in implementing differentiated instructional strategies in regular classes. The participants were 273 Portuguese primary school teachers with teaching experience ranging from 1 to 33 years. A 39-item questionnaire was used to evaluate teacher perceived difficulty in relation to different instructional strategies. Teacher responses were factor analysed and five different domains were identified: (1) activities and materials; (2) assessment; (3) management; (4) planning and preparation; and (5) classroom environment. Results showed that with the exception of the classroom environment domain, all the instruction practices in the remaining domains were considered to be difficult. In particular, the most difficult practices were under the domain of activities and materials and were associated with the adaptation of curricular elements (content, process, and product) based on student characteristics (readiness, interest, and learning profiles). The results also revealed a strong association between the activities and materials domain and the assessment domain. Some implications of these findings for initial teacher training and teacher professional development programmes are discussed.