955 resultados para Physical and theoretical chemistry


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Law's Ethical, Global and Theoretical Contexts examines William Twining's principal contributions to law and jurisprudence in the context of three issues which will receive significant scholarly attention over the coming decades. Part I explores human rights, including torture, the role of evidence in human rights cases, the emerging discourse on 'traditional values', the relevance of 'Southern voices' to human rights debates, and the relationship between human rights and peace agreements. Part II assesses the impact of globalization through the lenses of sociology and comparative constitutionalism, and features an analysis of the development of pluralistic ideas of law in the context of privatization. Finally, Part III addresses issues of legal theory, including whether global legal pluralism needs a concept of law, the importance of context in legal interpretation, the effect of increasing digitalization on legal theory, and the utility of feminist and postmodern approaches to globalization and legal theory.

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Ionic liquid gel materials offer a way to further utilise ionic liquids in technological applications. Combining the controlled and directed assembly of gels, with the diverse applications of ionic liquids, enables the design of a heady combination of functional tailored materials, leading to the development of task specific / functional ionic liquid gels. This review introduces gels and gel classification, focusing on ionic liquid gels and their potential roles in a more sustainable future. Ionic liquid gels provide the ability to build functionality at every level, the solid component, the ionic liquid, and any incorporated active functional agents. This allows materials to be custom designed for a vast assortment of applications. This diverse class of materials has the potential to yield functional materials for green and sustainable chemistry, energy, electronics, medicine, food, cosmetics, and more. The discussion of the development of ionic liquid gel materials for applications in green and sustainable chemistry centres on uses of ionic liquid gels in catalysis and energy.

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Absolute Se photoionization cross-section measurements and Dirac-Coulomb R -matrix calculations are reported for the photon energy range 18.0 eV – 31.0 eV, which spans the ionization thresholds of the 4 S 0 3/2 ground state and the low-lying 2 D 0 3/2,5/2 and 2 P 0 1/2,3/2 metastable states. The determination of the photoionization and recombination properties of n -capture element ions is motivated by their astrophysical detection and the importance of their elemental abundances in testing theories of nucleosynthesis and stellar structure.

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Localization is a fundamental task in Cyber-Physical Systems (CPS), where data is tightly coupled with the environment and the location where it is generated. The research literature on localization has reached a critical mass, and several surveys have also emerged. This review paper contributes on the state-of-the-art with the proposal of a new and holistic taxonomy of the fundamental concepts of localization in CPS, based on a comprehensive analysis of previous research works and surveys. The main objective is to pave the way towards a deep understanding of the main localization techniques, and unify their descriptions. Furthermore, this review paper provides a complete overview on the most relevant localization and geolocation techniques. Also, we present the most important metrics for measuring the accuracy of localization approaches, which is meant to be the gap between the real location and its estimate. Finally, we present open issues and research challenges pertaining to localization. We believe that this review paper will represent an important and complete reference of localization techniques in CPS for researchers and practitioners and will provide them with an added value as compared to previous surveys.

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Estudio de muestras recolectadas con el BIONESS a varias profundidades en trece estaciones.

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The prlmaiy objective of this study was to Identify and describe the physical and psychological stress factors that elementary school teachers experience and how teachers cope with stress. A secondary objective was to offer boards and teachers potential coping strategies counteracting stress and the effects of stress. The sample consisted of 120 elementaiy teachers from southern Ontario. Ten elementaiy schools were randomly chosen. The Teacher Stress Inventory questionnaire (Flmian, 1989) was used. Data were analyzed using a variety of statistics. Test norms and interpretations were performed based on standard results obtained from the author of the questionnaire (Flmian, 1988). Overall, the results indicated that work-related stressors were the main factor for teacher stress. This Included such factors as caseload/class is too big, too much administrative paperwork, and having little time to prepare lessons. Implications for further research and practical suggestions for further reseairch are discussed. Also a variety of recommendations to boards and for individual use are discussed. Some recommendations are having counselling available for teachers, workshops on how to handle stress, and learning how to breathe and using calm visualization.

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The synthesis and studies of two classes of poly dentate ligands are presented as two projects. In project 1, four new carboxamide ligands have been synthesised via the condensation of 2,2',6,6'-tetrachloroformyl-4,4'-bipyridine or 2,6-dichloroformyl pyridine together with heterocyclic amines containing pyridine or pyrazole substituents. The coordination chemistry of these ligands has been investigated and studies have shown that with a Cu(II) salt, two carboxamide ligands LJ and L2 afford large clusters with stoichiometries [Cu8(L1)4Cl16].CHCl3.5H2O.7CH3OH (I) and [Cu9(L2)6Cl6].CH3OH.5H2O.(C2H5)3N (II) respectively. [molecular diagram availabel in pdf]. X-ray diffraction studies of cluster (I) reveal that it has approximate S4 symmetry and is comprised of four ligands and eight copper (II) centers. Here, coordination takes place via amide 0 atoms, and pyrazole nitrogens. This complex is the first reported example of an octanuclear copper cluster with a saddle-shaped structure. The second cluster comprises nine copper ions that are arranged in a cyclic array. Each ligand coordinates three copper centers and each copper ion shares two ligands to connect six ligands with nine copper ions. The amide nitrogens are completely deprotonated and both amide Nand 0 atoms coordinate the metal centres. The cluster has three-fold symmetry. There are six chloride ions, three of which are bridging two neighbouring Cu(II) centres. Magnetic studies of (I) and (II) reveal that both clusters display weak antiferromagnetic interactions between neighbouring Cu(II) centers at low temperature. In the second project, three complexes with stoichiometries [Fe[N302](SCN)2]2 (III), R,R-[Fe[N3O2](SCN)2 (IV) and R,R-]Fe[N3O2](CN)2] (V) were prepared and characterized, where [N302] is a pentadentate macrocycle. Complex (III) was prepared via the metal templated Schiff-base condensation of 2,2',6,6'-tetraacetyl-4,4'-bipyridine together with 3,6-dioxaoctane-I,8-diamine and comprises of a dimeric macro cycle where the two Fe(II) centres are in a pentagonal-bipyramidal environment with the [N302] ligands occupying the equatorial plane and two axial NCS ligands. Complexes (IV) and (V) were prepared via the condensation of 2,6-diacetylpyridine together with a chiral diamine in the presence of FeCh. The synthetic strategy for the preparation of the chiral diamine (4R,5R)-4,5-diphenyl-3,6-dioxa-I,8-octane-diamine was elucidated. The chirality of both macrocycles (IV) and (V) was probed by circular dichroism spectroscopy. The crystal structure of (IV) at 200 K contains two independent molecules in the unit cell, both of which contain a hepta-coordinated Fe(II) and axial NCS ligands. Variable temperature magnetic susceptibility and structural studies are consistent with a high spin Fe(II) complex and show no evidence of any spin crossover behaviour. In contrast, the bis cyanide derivative (V) crystallizes with two independent molecules in the unit cell, both of which have different coordination geometries consistent with different spin states for the two Fe(II) centres. At 250 K, the molecular structure of (V) shows the presence of both 7- and a 6-coordinate Fe(II) complexes in the crystal lattice. As the temperature is lowered, the molecules undergo a structural change and at 100 K the structural data is consistent with a 6- and 5-coordinate Fe(II) complex in the unit cell. Magnetic studies confirm that this complex undergoes a gradual, thermal, spin crossover transition in the solid state. Photomagnetic measurements indicate this is the first chiral Fe (II) sea complex to exhibit a LIESST.

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This study was an investigation into whether strong teacher-student rapport relates to the drop-out rates of students in grade 9 and 10 health and physical education (HPE). In the study, One hundred and thirty-six grade 9 students from five high schools in Ontario participated in this study. Findings of whether or not rapport related to students’ decision to take an additional HPE credit beyond grade 9 did not prove conclusive. A significant multivariate interaction effect was not found; however, tests of between-subject effects on sex and grade 10 dropouts showed some interesting trends. More research is needed to further illuminate the link between teacher-student rapport and students’ enrollment in optional HPE classes.

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Ce mémoire utilise des données qualitatives provenant d’entretiens semi-structurés pour examiner les ressources qu’utilisent les individus qui font face à l’insécurité alimentaire sous l’angle du capital culturel de Pierre Bourdieu. Les participants étaient choisis parmi les usagers des organismes alternatifs qui œuvrent en sécurité alimentaire à Montréal. Tous étaient en situation d’insécurité alimentaire. Des analyses inductives et déductives étaient exécutées. Seize indicateurs de la forme du capital culturel incorporée, et trois indicateurs de chacune des formes institutionnalisées et objectivées ont été trouvés à être reliés aux stratégies qu’utilisaient les répondants pour améliorer leur situation alimentaire. Cette recherche nous indique que le capital culturel individuel joue un rôle dans les stratégies utilisées, incluant la participation dans les organismes communautaires. De plus, un manque de capital approprié peut servir comme barrière à la participation dans certaines stratégies ce qui pourra avancer des réflexions sur la justesse et l’efficacité des stratégies actuelles.

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The thesis entitled novel heterocyclic constructions mediated by nucleophilic carbenes and related chemistry, embodies the results of the investigations carried out to explore the reactivity patterns of the 1:1 zwitterions, generated in situ from various nucleophilic carbenes and DiMethyl AcetyleneDicarboxylate(DMAD) towards aldehydes and ketones. The traditional synthesis of complex organic molecules employs stepwise formation of bonds and involves multiple steps. Besides the sequential synthesis, in several instances, the desired product can also be obtained in one pot reactions of three or more starting compounds. Such reactions in which more than two starting materials react to form a product in such a way that the majority of the atoms of the starting materials can be found in the products are called multicomponent reactions(MCRs). The results of our investigations on the application of N-heterocyclic carbenes in multicomponent reaction with DMAD and aromatic aldehydes leading to the one pot synthesis of 2-oxy-maleate and furanone derivatives. It is interesting to note that dihydrofuran and lactone motifs are present in a number of biologically active natural products and other heterocyclic compounds. It is conceivable that the novel multicomponent reactions described herein will find application in the synthesis of a variety of heterocyclic compounds, and in natural product synthesis.