Thèses : « Meta physician »

1

Hasan, Abdullah Jamader. « The Concept of person : the approach of a descriptive metaphysician ». Thesis, University of North Bengal, 1998. http://hdl.handle.net/123456789/43.

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Orcutt, Venetia L. Henson Robin K. « The supply and demand of physician assistants in the United States a trend analysis / ». [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-3633.

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3

Hicks, Michelle B. Wheeler Maurice B. « Informed consent in obstetric anesthesia the effect of the amount, timing and modality of information on patient satisfaction / ». [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-9771.

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4

Grimes-Marchan, Thomas V. Cundari Thomas R. « Quantum perspectives on physical and inorganic chemistry ». [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-5172.

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5

Carothers, Cathleen de Souza Lourenco Collins John R. « Minimum levels of physical activity and perceived quality of life ». [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-6127.

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6

Boyer, Elizabeth M. Petrie Trent. « Psychological benefits of sport participation and physical activity for adolescent females ». [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-3997.

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7

Mintz, Benjamin Wilson Angela K. « Reducing the computational cost of Ab Initio methods ». [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-9061.

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8

Maulden, Robert. « Tectonics in architecture : from the physical to the meta-physical ». Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/78804.

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Thesis (M. Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 1986.
MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH
Includes bibliographical references (p. 195-201).
Tectonics in architecture is defined as "the science or art of construction, both in relation to use and artistic design." It refers not just to the "activity of making the materially requisite construction that answers certain needs, but rather to the activity that raises this construction to an art form." It is concerned with the modeling of material to bring the material into presence: from the physical into the meta-physical world. The topic is, in part, a reaction to some contemporary trends in architecture. Part one discusses two current trends perceived to be negative: the effacement of history, both in an architectural and a temporal sense; and the tendency toward scenographic representation. Part two discusses the external references and internal references of buildings. These references are developed in two ways: a building's inter-consciousness and inner-consciousness. The former is concerned with the general circumstances of a building, (physical, social, political, economic), or in Heidegger's terms, the way in which it "gathers the fourfold," and the latter is concerned with the intrinsic properties of a building. The two are completely interdependent, however, this thesis is primarily concerned with a building's inner-consciousness. Part three defines tectonics first by discussing its relation with meta-physics; second by tracing an abbreviated lineage of nineteenth century German practitioners and theorists; third by describing different kinds of tectonic expression and finally by outlining only a few "subjects" of tectonic architecture. Part four examines two examples in detail - the 25bis Rue Franklin Apartment Building by August Perret, and the Richards Medical Research Laboratories by Louis Kahn. These are intended to give concrete examples of some of the issues and subjects discussed previously in the thesis. Tectonics is primarily concerned with the making of architecture in a modem world. Its value is seen as being a partial strategy for an architecture rooted in time and place, as well as an architecture of "depth." In bringing the physical into the meta-physical, tectonics begins to talk of a poetic of construction.
by Robert Maulden.
M.Arch.

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9

LaBorde, Cicely T. Kaminski Patricia L. « The role of attention-deficit/hyperactivity disorder and parental misperceptions in risk for child physical abuse ». [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-5154.

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10

Lee, Yi-Ching Dickstein Rebecca. « Physical map between marker 8O7 and 146O17 on the Medicago truncatula linkage group 1 that contains the NIP gene ». [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-5152.

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11

LeCoultre, Trent David. « A meta-analysis and risk assessment of heavy metal uptake in common garden vegetables ». [Johnson City, Tenn. : East Tennessee State University], 2001. http://etd-submit.etsu.edu/etd/theses/available/etd-1107101-131704/unrestricted/LeCoultret112101a.pdf.

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12

Peterson, Janet Walker Moen William E. « Networked generation youth's information seeking process an examination of cognitive, affective, and physical information seeking behaviors and problem solving techniques / ». [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-6063.

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13

Myers, Tiffany Jo. « School-based physical activity interventions a meta analysis / ». [Ames, Iowa : Iowa State University], 2008.

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14

Krupitzer, Craig. « Body mind spirit mediating the (meta)physical tradition / ». This title ; PDF viewer required. Home page for entire collection, 2004. http://archives.udmercy.edu:8080/dspace/handle/10429/9.

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15

Lin, Shyh-Hsiang. « Meat analog development and physical, chemical, and sensory properties / ». free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9924899.

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16

Lynn, Matthew Allen. « Metal, ligand, and symmetry influences on metal-metal bonds : Photoelectron spectroscopy and theory ». Diss., The University of Arizona, 2000. http://hdl.handle.net/10150/284089.

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Three sets of metal-metal bonded systems of the form M₂(L ͡ L)₄ have been studied by gas-phase ultraviolet photoelectron spectroscopy and electronic structure calculations to understand the electronic structures of and bonding in these molecules. The ligand sets range from the relatively poor electron donor trifluoroacetate ligand, to hydroxymethylpyridinate (mhp), and finally to the relatively strong electron donor N,N'-diphenylformamidinate (form) ligand. Not only does this study elucidate the methods by which metal and ligand interact throughout a series of differing electron donor ligand sets, but it also presents a cohesive understanding of the electronic structures of these systems in terms of overall molecular symmetry. In particular, the relative stabilities and orbital characters of the metal-metal bonding and antibonding orbitals are probed to understand the ability of a particular ligand set to affect the ability of two metal atoms to bind together. First, compounds of the form M₂(form)₄ (M = Cr, Mo, W, Ru, Rh, Pd) are examined. The spectra of the metal-metal quadruple bond-containing systems (i.e., M₂(form)₄ where M = Cr, Mo, W) are used to identify several metal- and ligand-based ionization features, which can then be used to identify the additional metal-based features in the spectra of the remaining systems. Given the ease with which functional groups can be added to the formamidinate ligand, a series of substituted Mo₂(form)₄ systems have been prepared and their ionization data have been compared with solution-phase electrochemical results. Next, the electronic structures of M₂(O₂CCF₃)₄ (M = Mo, Rh) are studied. Variable energy photon experiments reveal a predominance of ligand character in the M-M σ and π orbitals, despite the relatively poor overall electron donor ability of the ligand. The means by which such a ligand can interact by symmetry with these metal orbitals are studied by computational methods. Finally, the bonding in M₂(mhp)₄ (M = Cr, Mo, W, Ru, Rh) systems is probed. The lower symmetry of these molecules and the intermediate donor properties of this ligand set allow for correlation with the electronic structures of M₂(form)₄ and M₂(O₂CCF₃)₄. Unlike for the higher symmetry systems, ligand involvement in the M-M δ bond is observed and can be understood in terms of molecular symmetry arguments.

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17

Wallace, Andrew Simon. « Colloidal metal dispersions ». Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239329.

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18

GENTILE, Ambra. « COGNITION AND PHYSICAL ACTIVITY ACROSS AGES ». Doctoral thesis, Università degli Studi di Palermo, 2021. http://hdl.handle.net/10447/501295.

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19

Zalich, Michael Andrew. « Physical Properties of Magnetic Macromolecule-Metal and Macromolecule-Metal Oxide Nanoparticle Complexes ». Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/27528.

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Magnetic nanoparticles are of considerable interest owing to their potential applications in biotechnology and the magnetic recording industry. Iron oxides have received much attention owing to their oxidative stability and biocompatibility; however, other transition metals and their alloys are also under investigation. Cobalt has one of the largest magnetic susceptibilities of these materials, but it readily oxidizes upon exposure to air resulting in antiferromagnetic oxide. Hence, coating cobalt nanoparticles with an oxygen-impermeable sheath would confer numerous benefits. Cobalt nanoparticles were prepared by the thermolysis of dicobalt octacarbonyl in two block copolymer micellar systems, wherein the copolymers were precursors to graphite or silica. Subsequent heat treatment of the samples at 600-700oC was conducted to condense the polymer coating around the cobalt nanoparticles and form oxygen impervious graphite or silica sheaths. Magnetic and structural characterization of these novel materials afforded pertinent information about their physical properties. Magnetic susceptometry indicated that the graphite coated cobalt nanoparticles resisted oxidation for over one year. The silica coated cobalt nanoparticles had high saturated specific magnetic moments, but the coatings were brittle and grinding the particles resulted in oxidation over time. Transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and energy-filtered TEM (EFTEM) were employed to study particle size and structural differences of the cobalt nanoparticles before and after heat treatment. The mean particle size and size distribution increased for the graphite coated cobalt particles, due to particle sintering at 700oC. In the silica coated cobalt nanoparticle system, the mean particle size increased when the sample was heat-treated at 600oC leading to a bimodal distribution. This bimodal distribution was explained by a fraction of the particles sintering, while others remained discrete. When the silica system was heat treated at 700oC, the particle size and size distribution remained similar to those of the pre-heat-treated sample, indicating that no sintering had taken place. The rapid pyrolysis of the polymer at 700oC may serve to lock the cobalt nanoparticles into a silica matrix, thus preventing them from coming into contact with one another and sintering. Several diffraction techniques (selected area electron diffraction (SAD), nano-beam electron diffraction (NBD) and x-ray diffraction (XRD)) were used to probe the crystal structure of graphite and silica coated cobalt nanoparticles, which was determined to be predominantly face-centered cubic. Anisotropic magnetic nanoparticles (nanorods) have an increased magnetophoretic mobility over spherical magnetic nanoparticles with the same equatorial radius. This property makes them attractive candidates for in vivo biological applications. Anisotropic mixed ferrite nanoparticles were coated with a biocompatible hydrophilic block copolymer to render them dispersible in aqueous media. Polymer coated mixed ferrite particles exhibited magnetic properties similar to that of pure magnetite, as the total level of other transition metals in the nanoparticulate system was less than 5%. Electron energy loss spectroscopy (EELS) and (EFTEM) confirmed that the dominant elements in the mixed ferrite nanoparticles were iron and oxygen. Furthermore, HRTEM, SAD and XRD analyses indicated that the crystal structure for the mixed ferrite nanoparticles was inverse spinel. X-ray diffraction peaks at low angles for the coated mixed ferrite rods corresponded to poly(ethylene oxide) peaks, suggesting that the block copolymer employed as a dispersant was associated with the particles.
Ph. D.

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20

Sutherland, Ian Michael. « Metal-catalysed asymmetric hydrogenation ». Thesis, University of Hull, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304289.

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21

Watts, Andrew M. « Polysiloxane supported metal catalysts ». Thesis, University of Bath, 1986. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370993.

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22

Hutchison, Stephanie Elise. « Meta : discourses from dancers inside action machines ». Thesis, Deakin University, 2017. https://eprints.qut.edu.au/112130/2/164341748.

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The dancer’s perspective is crucial to developing the discourse surrounding studio based dance practice and processes, as it is within the act or context of dancing that the experience of dance resides. From the perspective of dancing I am seeking to examine and articulate how different forms of external frameworks and their application in studio-based dance settings construct opportunities to challenge how dancer’s bodies can be developed or altered through their engagement with specific practices and processes. Hence, meta: discourses from dancers inside action machines, seeks to examine studio-based processes in dance from a dancer’s perspective. More specifically, I aim to examine the application of external frameworks such as equipment, scores, task-based processes, exercises, and digital technologies within studio-based dance practices and the effect these practices, protocols and strategies have on dancers’ bodies. The work of Jennifer Roche, Michael Huxley, and Bud Blumenthal are some examples of the discourse surrounding the work of dancers that is beginning to form, as the role of dancers within contemporary choreographic practices comes under increasing focus. (Roche 2015, Huxley 2015, Blumenthal 2012) Given the complexity of dance as an ecosystem of thought, movement and practice, and given the wide range of individual practices, both dancer-ly and choreographic, that sit within this field, the role and practice of the dancer requires extensive examination. Examination of dancers’ work should take into account numerous perspectives and methodological viewpoints if we are to generate a deep understanding and articulation of how the processes of the dancer function within contemporary dance practice...

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23

Brown, Ronald. « A study of hydrocarbon reactions over supported metal catalysts : support and metal dependence ». Thesis, University of Edinburgh, 1990. http://hdl.handle.net/1842/13013.

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24

English, Jason B. « Electronic structure investigations of multiple bonding between atoms : From metal-nitrogen triple bonds to metal-metal triple and quadruple bonds ». Diss., The University of Arizona, 2002. http://hdl.handle.net/10150/280021.

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The nature of multiple bonding involving transition metal atoms has been explored via photoelectron spectroscopic and computational studies of molecules containing metal-metal quadruple and triple bonds as well as of molecules containing formal metal-nitrogen triple bonds. The principles governing the nature of the multiple bonding in these systems are similar whether the multiple bonding occurs between two transition metals or between a transition metal and a nitrogen atom. First, the electronic structures of the R₃M≡N molecules, where R = ᵗBuO (Cr, Mo, W); iPrO (Mo); (CH₃)₂CF₃CO (Mo); and Cl (Mo), are examined by photoelectron spectroscopy in conjunction with density functional calculations. To assign the features seen in the photoelectron spectra, close attention is paid to the effects of (1) metal substitution and (2) alkoxide (or Cl) substitution. Examination of the photoelectron spectra of the full series of alkoxide-substituted molecules allows the relative positions of the ionizations from the M≡N σ and π orbitals to be identified. Of great importance to the electronic structure of these molecules are the alkoxide orbital combinations that mix strongly with the M≡N σ and π orbitals. The importance of the ancillary ligand combinations is clearly demonstrated by the photoelectron spectroscopic and computational studies of Cl₃Mo≡N. The replacement of the alkoxide ligand with chlorides greatly simplifies the resultant photoelectron spectrum, allowing all of the valence ionizations to be assigned. Next, the bonding in the M₂X₄(PMe₃)₄ molecules, where M = Mo (X = Cl, Br); W (X = Cl); and Re (X = Cl, Br, I), is explored by photoelectron spectroscopic investigations in conjunction with electronic structure calculations. From these investigations, the ionizations from the metal-based orbitals as well as several ligand-based orbitals have been assigned. The first ionization energies of both the molybdenum (δ) and rhenium (δ*) molecules decrease as the electronegativity of the halide increases. The origin of this inverse halide effect is explored. Finally, the nature of the quadruple metal-metal bond in the M₂(chp)₄ molecules (M = Cr, Mo, W; chp = 2-chloro-6-oxo-pyridinate) is probed. For all three metal systems, an ionization from the M₂ δ orbital can be seen. This is only the second time a distinct ionization feature has been noted for ionization of the delta orbital from a dichromium molecule. Comparisons with the previously studied M₂(mhp)₄ molecules (mhp = 6-methyl-2-oxo-pyridinate) allow for a better understanding of the electronic structure of these molecules.

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25

Kumar, U. « Biosynthesis of metal/metal-oxide nanoparticles and measurement of their physical, biophysical properties ». Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2011. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3774.

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26

Chumakov, V. I., et O. Kharchenko. « Metal Nanoparticle Producing Ased on Electro-physical Methods ». Thesis, GEORGIAN TECHNICAL UNIVERSITY, 2016. http://openarchive.nure.ua/handle/document/9655.

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27

Fisk, J. D. « Physical and electrochemical characterisation of reticulated vitreous carbon ». Thesis, University of Exeter, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269738.

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Hutchings, M. J. « Voltammetry of metal dialkyldithiophosphate systems ». Thesis, Cardiff University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372342.

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29

Murphy, Carl. « A meta-ontological criticism of Eli Hirsch's semanticist attack on physical object ontology ». Thesis, Cardiff University, 2017. http://orca.cf.ac.uk/105415/.

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Physical object ontology is a sub-branch of ontology which is primarily concerned with three interrelated issues. These are the composition, material constitution, and manner of persistence for physical objects. Philosophers who take up positions on such issues often disagree over what objects they think the world contains – for example a mereological nihilist will argue that there are no composite objects, and thus would say that the ordinary objects that appear to be all around us do not actually exist. Such disputes are thought to be substantive and depend for their truth on what the world itself is actually like. Against this Eli Hirsch develops a meta-ontological argument which states that the debates in physical object ontology are merely verbal, and that what is going in these debates is that each side is simply speaking an alternate language in which their claims come out trivially true and the claims of their opponent come out trivially false. Thus there is no actual disagreement over the facts. This position of Hirsch’s I call semanticism. The purpose of this thesis is to articulate Hirsch’s position, demonstrating its Carnapian roots, but also showing how Hirsch, by making several key commitments, intends his position to be distinctive from a thoroughgoing Carnapianism and its potentially unattractive commitments to anti-realism and/or verificationism. However, in this thesis I develop a number of problems for Hirsch’s position, showing that his modified version of Carnapianism is untenable, and that he is forced between giving up his central contention or retreating into a more thoroughgoing Carnapianism.

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Tarr, Christopher W. « The Effects of Physical Exercise on Stereotypic Behaviors in Autism| A Meta-Analysis ». Thesis, Slippery Rock University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10984780.

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The prevalence rate of children with autism has been on the rise for the past 20 years. A hallmark characteristic of this disorder is the presence of stereotypic behaviors. Children who engage in stereotypic behaviors experience difficulties in effectively interacting with their surrounding environment. Both consequence-based and antecedent based interventions have been successful in decreasing these interfering behaviors. The performance of physical exercise has shown positive results as both a consequence based and antecedent based intervention in reducing stereotypic behaviors. The current investigation conducted a meta-analysis on the effects of physical exercise on stereotypic behaviors in individuals with autism. This study was able to run this meta-analysis using both aggregate score studies and single subject design studies. This study identified 10 research articles that met all of the inclusion criteria. The 10 articles were coded according to sixteen primary moderators and four peripheral moderators. The 10 articles produced an overall large effect size of d = -.456. This large effect size demonstrated that physical exercise is effective in decreasing stereotypic behaviors in individuals with autism. However, no significant statistical difference was observed within any of the primary and peripheral moderators. The lack of significant statistical difference within any of the moderators lead the current investigator to conclude that the effect of physical exercise on stereotypic behaviors in individuals with autism may not be impacted by external factors. Further research is needed to determine the internal neurobiological effects of physical exercise on stereotypic behaviors in individuals with autism.

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31

Germain, Jesse Luke. « Assessing the relationship between perceived and actual physical fitness a meta-analytic review / ». [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0004268.

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32

Jobling, M. G. « Physical and genetic analysis of heavy metal resistance plasmids ». Thesis, University of Liverpool, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372683.

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33

Gedikoglu, Ayca Clarke Andrew Douglas. « Effect of antimicrobial agents on physical, chemical and microbiological characteristics of ready-to-eat bologna ». Diss., Columbia, Mo. : University of Missouri--Columbia, 2008. http://hdl.handle.net/10355/5777.

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The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed September 24, 2009). Thesis advisor: Dr. Andrew D. Clarke. Includes bibliographical references.

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34

Redfern, C. M. « Electronic structure of transition metal complexes ». Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235094.

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35

Hall, Tracey Jane. « Mechanisms of metal-catalysed enantioselective hydrogenation ». Thesis, University of Hull, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265129.

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36

Moock, K. H. « Electrochemical studies on transition metal halides ». Thesis, University of Glasgow, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375467.

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37

Abbott, Andrew. « Transition metal electrochemistry in aromatic solvents ». Thesis, University of Southampton, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.330164.

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38

Brooker, Alan Thomas. « New routes to metal salt complexes ». Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359761.

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Smith, Shelley Hunnings. « Solid State Effects in the Reactions of the Meta and Pura Trifluorodiazomethane/Beta-Cyclodextrin Inclusion Complexes ». W&M ScholarWorks, 1990. https://scholarworks.wm.edu/etd/1539625588.

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40

Harrison, Mark Robert. « One-dimensional, mixed-metal sulphides – structural and physical properties ». Thesis, University of Hull, 2011. http://hydra.hull.ac.uk/resources/hull:5281.

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New one-dimensional sulphides based on Ba2CoS3 have been synthesised and their structural and electronic properties investigated. The starting point was the one-dimensional sulphide Ba2CoS3, which shows one-dimensional anti-ferromagnetism, metallic-like behaviour and a small negative magnetoresistance. Cationic substitutions were carried out on both the barium and cobalt sites of Ba2CoS3. The substitution of zinc for cobalt into Ba2CoS3 resulted in the formation of the series Ba2Cox1−xZnxS3 (x = 0.0-1.0). Ba2Co1−xZnS3 compounds maintain the one-dimensional structure but become paramagnetic and show semiconducting properties. Interestingly significant values of magnetoresistance (up to −25%) are found in the series. The origin of the magnetoresistance is currently unknown although it is suspected that there is some extrinsic contribution. The compound Ba2Co0.75Fe0.25S3 has also been successfully synthesised although attempts to form compounds with higher iron content were not successful. A large number of compounds in the series Ba2Zn1–xMxS3 (M = Fe, Mn, Cr, Ni) have also been synthesised and initial investigations into the properties of these materials show that again they exhibit negative magnetoresistance. Finally Ba1.9K0.1CoS3 has been synthesised although no investigation into the properties has yet been carried out.

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41

Yang, Minghui. « Synthesis and physical properties study on mixed metal oxynitrides ». Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/4615.

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Mixed metal oxynitrides have attracted attention due to their interesting chemical and physical properties in the past twenty years. In this thesis, four series of mixed metal oxynitrides have been investigated. The samples have been synthesized by both thermal ammonolysis and high pressure high temperature methods. The structural exploration covers perovskite, scheelite and pyrochlore types. The structural studies were carried out using powder X-ray and neutron diffraction, and magnetic and conducting properties have been explored. A series of new RZrO2N (R = Pr, Nd and Sm) perovskites were synthesized using high pressure high temperature methods (HPHT) via a direct solid state reaction of R2O3 with Zr2ON2. All three new phases crystallize in the orthorhombic Pnma perovskite superstructure, and the structural distortion increases with decreasing R3+ ionic radius. RZrO2N contains both R3+ and d0 Zr4+ and thus shows a potential for multiferroic properties. EuWO1-xN2+x perovskites with a wide range of nitrogen contents (-0.16 ≤ x ≤ 0.46) were synthesized by thermal ammonolysis of an oxide precursor Eu2W2O9. Ferromagnetic ordering below a Curie temperature TC =12 ± 1 K and negative colossal magnetoresistances (CMR) have been discovered in these samples. In particular, for the lowest doped sample, EuWO0.96N2.04, CMR ≥ 99.7% was observed at 7 K. The possibility of tuning the physical properties by altering the chemical composition has been demonstrated. A linear relationship between the lattice parameter and nitrogen content of EuWO1+xN2-x was observed. An investigation has been made of the Eu-Mo-O-N system. A new pyrochlore oxynitride series Eu2Mo2O6-xN2+2x/3 (0.20 ≤ x ≤ 2.25) was synthesized by ammonolysis of Eu2Mo2O7. A ferrimagnetic ordering and semiconducting behavior has been observed in these samples. A detailed structural study of SrMO2N (M = Nb, Ta) has been performed using variable temperature neutron and electron diffraction. Partial anion order has been observed in both samples up to 750 oC. It is consistent with cis-ordering of the two nitrides in each MO4N2 octahedron. At low temperatures, this order directs the tilting of the octahedron to form a pseudo-tetragonal superstructure. It creates zig-zag MN chains in two or three dimensions within the lattice. This principle can be used to predict the local structures of perovskite-related oxynitrides AMO3-xNx.

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42

Ainsworth, Christopher Michael. « Synthesis, structural characterisation and physical properties of metal oxychalcogenides ». Thesis, Durham University, 2017. http://etheses.dur.ac.uk/12178/.

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Chapter 1 is a literature review on oxychalcogenide materials, with emphasis on structures similar to those discussed in later chapters of this thesis. These materials display a whole host of interesting properties and have garnered particular interest in recent years. Chapter 2 describes the synthetic methods and characterisation techniques used to study the materials discussed in this thesis. It includes the theory behind powder diffraction techniques, Rietveld refinement, and a range of physical property measurement techniques. Chapter 3 discusses the synthesis, structural characterization, and physical properties of the new transition metal oxyselenide Ce2O2ZnSe2. It adopts a ZrCuSiAs-related structure with Zn2+ cations in a new ordered arrangement within [ZnSe2]2– layers. The cell volume of the sample, and consequently the physical properties, can be controlled by subtle modification of the synthetic conditions. Ce2O2ZnSe2 is a semiconductor at all cell volumes with experimental optical band gaps of 2.2, 1.4, and 1.3 eV for high-, intermediate-, and low-cell volume samples, respectively. SQUID measurements show Ce2O2ZnSe2 to remain paramagnetic down to low temperature. Chapter 4 reports 60 new compositions across the La2O2(Fe1–yZny)Se2, La2O2(Zn1–yMny)Se2, La2O2(Mn1–yCdy)Se2, Ce2O2(Fe1–yZny)Se2, Ce2O2(Zn1–yMny)Se2, Ce2O2(Mn1–yCdy)Se2, La2 zCezO2FeSe2, La2–zCezO2ZnSe2, La2–zCezO2MnSe2, and La2–zCezO2CdSe2 solid solutions. These series reveal that the transition metal arrangement in the Ln2O2MSe2 (Ln = La & Ce, M = Fe, Zn, Mn & Cd) compounds can be systematically controlled by either Ln or M substitution leading to an “infinitely adaptive” structural family. Chapter 5 describes a new family of compounds containing both +1 and +2 transition metal ions in the La2O2Cu2–2xCdxSe2 family. It shows how Cu1+ and Cd2+ ions segregate into distinct fully occupied and half occupied checkerboard-like layers respectively, leading to complex long-range superstructures in the 3rd (stacking) dimension. To understand the structure and microstructure of these new materials a new methodology for studying low-probability stacking faults using a Rietveld-compatible supercell approach was developed and applied. Chapter 6 investigates the solid solution La2–zSrzO2Cu0.5CdSe2. This takes the compound La2O2Cu0.5CdSe2 (x = 0.5 from Chapter 5, with a 1:1 ratio of Cu:Cd layers) and Sr2+ dopes on the La3+ site, where the solubility limit is shown to be ~15% (z = 0.3). At z = 0, ρ(300 K) = 1.5×104 Ω cm. After Sr doping, ρ(300 K) decreased significantly to 8.2×101 Ω cm at z = 0.05, reaching a minimum at ~6×10 1 Ω cm for z = 0.3. DFT calculations of La2O2CuCd0.5Se2 show that the valence band consists of Cu 3d and Se 4p states, hence electronic conduction should be confined to [Cu2Se2]2- layers. Chapter 7 extends the work of Chapter 5 by discussing three more solid solutions analogous to La2O2Cu2–2xCdxSe2. These are La2O2Cu2–2xFexSe2, La2O2Cu2–2xZnxSe2 and La2O2Cu2 xMnxSe2. It also investigates the effect of systematically varying the +2 transition metal size in the solid solutions La2O2Cu(M0.5–yM’y)Se2 and La2O2Cu0.667(M0.667–yM’y)Se2 (M/M’ = Fe/Zn, Zn/Mn & Mn/Cd). Chapter 8 will briefly summarise and link the work described in Chapters 3 to 7.

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SAVINO, UMBERTO. « Physical properties of metal-oxide surfaces for CO2 valorisation ». Doctoral thesis, Politecnico di Torino, 2020. http://hdl.handle.net/11583/2823956.

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Heiligers, Christiané. « On the microstructure and physical properties of hot pressed (Hf, Ti) C ». Thesis, Nelson Mandela Metropolitan University, 2007. http://hdl.handle.net/10948/523.

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The microstructure and physical properties of hot pressed (Hf, Ti) C have been investigated with the aim of producing a cutting tool material with similar hardness to that of WC-Co and TiC-based cermets. Sintered samples were hot pressed from HfC0.7 and TiC0.9 powders using powder metallurgical techniques and the processing cycle was optimized for this system. Ni was used as a binder in selected samples and C black was added to compensate for sub-stoichiometry and to aid in the reduction of oxides formed during milling. Microstructural analyses were performed by scanning and transmission electron microscopy (SEM and TEM) and the composition was determined from X-ray diffraction (XRD) and energy dispersive X-ray spectrometry (EDS). The physical properties measured are density and Vickers hardness, and the indentation fracture toughness was determined using the Shetty formula. The fundamental interactions between HfC, TiC and Ni during hot pressing were investigated and the results obtained used to explain the microstructure that develops in samples made from powder mixtures. The interactions studied are the inter-diffusion of HfC and TiC through the solid state, and the dissolution and re-precipitation rate of the carbides in a liquid Ni binder. EDS analysis revealed that the rate at which Ti diffuses into HfC is higher than the rate at which Hf diffuses into TiC. Upper limits to the diffusion coefficients for these processes are determined and show that solid solution carbides will form from HfC + TiC powder mixtures at 2000 ºC in 1 hour if the average powder particle size is less than 5 μm. The diffusion rates decrease with a decrease in hot pressing temperature but mass transport between the phases can be enhanced by addition of a metallic binder. TEM and EDS analysis shows that Ni wets TiC more efficiently than HfC and that the solubility of TiC in Ni is also higher than that of HfC. The grain size of the carbide phases increases with an increase in the rate at which they dissolve into and re-precipitate from the liquid binder. The crystal structure of the binder phase depends on the concentration of Ti and Hf that remain in the binder after cooling and the carbide phase in which the binder is embedded. Analysis of TEM electron diffraction patterns show that the binder phase consists of cubic solid solutions as well as intermetallic and cubic phases in which atomic ordering is observed.

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Grey, John K. « Vibronic luminescence properties of tetragonal transition metal complexes ». Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=85072.

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The luminescence properties of trans-dioxo rhenium(V) and osmium(VI) [d2] and square-planar platinum(II) and palladium(II) [d8] transition metal complexes have been studied as a function of temperature and pressure. Both types of complexes studied have idealized D4h point group symmetry with the d2 systems representing the tetragonally compressed limit of a six-coordinate complex in the D4h point group and the d8 systems representing the tetragonally elongated limit. The observed luminescence in both classes of complexes has been assigned as a metal-centered (d → d) 3Eg → 1A1g transition. The application of external pressure provides a means to induce minor changes in the molecular geometries of these model systems that reveal the delicate interplay between structural and electronic properties. Pressure-dependent spectroscopic data are analyzed quantitatively using theoretical models adapted from high-resolution low-temperature spectra where emitting state displacements along vibrational coordinates are determined from resolved vibronic structure. These combined experimental and theoretical techniques allow for a full characterization of the ground and emitting state potential energy surfaces and their explicit dependence on structural parameters.
trans-Dioxo rhenium(V) and osmium(VI) complexes have formal metal-oxo double bonds and the electronic structures of these tetragonal systems are also influenced by the ancillary ligands bonded to the trans-[MO2]n+ moiety. A series of trans-[ReO2]+ complexes with substituted N,N,N',N'-ethylenediamine ligands were studied that show markedly varying luminescence energies and bandshape characteristics. Pressure-dependent luminescence spectra at room temperature show resolved structure in the high-frequency (~900 cm-1) O = Re = O symmetric (a1g ) stretching mode. Variable pressure causes the vibronic patterns to change and a detailed analysis is performed using potential energy surfaces from a coupled states model with the time-dependent theory of spectroscopy. Additional work was carried out on trans-dioxo osmium(VI) complexes with monodentate isothiocyanate ligands that show highly resolved vibronic structure at low temperature in both metal-ligand and ligand-centered a1g vibrational modes, allowing for a detailed analysis of the emitting state geometries.
Temperature- and pressure-dependent spectroscopic studies of thiocyanate and selenocyanate complexes of platinum(II) and palladium(II) revealed significant variations of luminescence intensities and lifetimes. (Abstract shortened by UMI.)

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Yao, Jing Wen. « Systematic structural studies in metal complex chemistry ». Thesis, Durham University, 1998. http://etheses.dur.ac.uk/5055/.

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A procedure is presented for detecting geometrical preferences, deformations and interconversion pathways between different geometries for the transition metal coordination sphere ML(_n). A discrepancy index [R(_ang)(x)] was proposed initially to address the problems of dimensionality and permutation complexity in the systematic analysis of coordination sphere geometry with higher coordination numbers (n > 7). But it can also be used generally for the lower coordination numbers. A set of standard geometries for coordination numbers 2-9 are presented and the angles between the center point and each vertex for the polyhedra which are used to describe the coordination sphere geometries for coordination numbers 7-9 are idealised. These angles correspond to the metal-ligand valence angles in the coordination complex and are used as the standard values to measure the deviation of a real coordination sphere in the complex from these standard polyhedra. Geometry of each coordination sphere (ML(_7-9)) from the Cambridge Structural Database (CSD) is identified by the calculations of R(_ang)(x) values. Also the unique enumeration numbers of the ligands corresponding to each geometry can be derived over the n! ligand permutations. The different geometrical clusters and interconversion pathways from one to another are mapped in a designed two-dimensional plot. The symmetry coordinates and principal component analysis are initially applied in these higher coordination number systems. They not only map the clusters represented to those standard geometries in the different symmetric point groups but also provide and confirm the interconversion pathways between the different geometries. The other systematic study involves the analysis and correlation of the metal σ-π bond in the transition metal alkyne and alkene complexes from the CSD. Geometrical features of this specific bond are examined in the view of structure and some useful correlation between the key geometrical parameters are defined. Finally, X-ray crystal structure determinations are briefly described and the crystal structures of ten transition metal compounds in coordination numbers 4-6 are presented.

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Styring, Peter. « Neutral and ionic metal-containing liquid crystals ». Thesis, University of Sheffield, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285012.

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Hodson, Lisa Francesca. « Catalysis by single and mixed metal phosphates ». Thesis, University of Liverpool, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337133.

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Annett, J. F. « The interaction of helium with metal surfaces ». Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355875.

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Lahart, I. M. « Physical activity and breast cancer ». Thesis, University of Wolverhampton, 2014. http://hdl.handle.net/2436/332113.

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Background: Breast cancer is the most frequently diagnosed cancer and a leading cause of cancer death among females, both worldwide and in the UK. Although, UK incidence of breast cancer is rising, breast cancer mortality rates are falling, due largely to early detection and improved treatment. As a result there are more women living with a diagnosis of breast cancer than ever before. Due mainly to side-effects of adjuvant therapy, breast cancer patients may require diagnostic, therapeutic, supportive or palliative services many years post-diagnosis, which poses a major challenge to already stretched healthcare services. Accordingly, effective and inexpensive interventions that can alleviate treatment side-effects, improve health, quality of life and potentially reduce risk of early mortality are required for breast cancer patients. Awareness of the positive influence that physical activity can have on breast cancer development and outcome is an important determinant of physical activity levels. A higher level of physical activity before and after breast cancer diagnosis is related to a lower risk of all-cause and breast cancer-related mortality. Randomised controlled trials have reported beneficial effects of physical activity interventions on outcomes relating to health, quality of life and mortality risk among breast cancer survivors. Aims: The present project aimed to: 1) assess awareness of the role of physical activity on breast cancer risk and the sufficiency of physical activity undertaken in women attending the NHS breast screening programme (NHSBSP), 2) compare physical activity levels of women at different stages of breast cancer pathway, 3) investigate the effects of a low-cost six-month home-based physical activity intervention on physical activity, body mass, health-related quality of life (HRQoL), insulin resistance and blood lipid profiles of breast cancer survivors and 4) assess the effects of our home-based intervention on cardiorespiratory fitness in a subset of breast cancer survivors. Methods: A total of 309 volunteers (188 NHSBSP attendees, 41 breast cancer patients undergoing chemotherapy and 80 post-treatment breast cancer survivors) participated in the current project. Physical activity was assessed via the International Physical activity Questionnaires (IPAQ). In studies one and two, Body mass and body mass index (BMI) were assessed directly in chemotherapy patients and breast cancer survivors, and indirectly from self-reported values in NHSBSP attendees. While in study three, body fat percentage was measured via bioelectrical impedance analysis, HRQoL was assessed using the Functional Assessment of Cancer Therapy-Breast (FACT-B) questionnaire and fasting blood samples were taken to measure lipid, glucose and insulin concentrations at baseline and post-six month home-based physical activity intervention. In study four, a random subsample of 32 breast cancer survivors undertook an exercise tolerance test to establish peak oxygen uptake values. Results: A high proportion (70%) of NHSBSP attendees engaged in low-moderate levels of physical activity and performed low amounts of recreational physical activity. Attendees demonstrated high awareness (75%) of the role of physical activity in reducing breast cancer risk but those categorised as “low activity” were significantly unaware of insufficiency of activity (p<0.05). Chemotherapy patients and breast cancer survivors had significantly lower levels of total physical activity than NHSBSP attendees (p<0.001 and p<0.05, respectively). The randomised controlled trial revealed significant improvements in total physical activity, body mass (p<0.05), BMI (p<0.05) HRQoL (breast cancer subscale, p<0.01; trial outcome index, p<0.05) and total (p<0.01) and low-density lipoprotein (p<0.05) cholesterol concentrations in the intervention group compared to usual care, and significant improvements in cardiorespiratory fitness (p<0.05) in a subsample of breast cancer survivors allocated to intervention. Conclusions: Physical activity interventions that incorporate strategies aimed at increasing awareness of recommended physical activity guidelines may be required in populations at risk of breast cancer. A relatively large proportion of women at risk of breast cancer may not be sufficiently exposed to the potential benefits of physical activity on breast cancer outcomes. Post-treatment breast cancer patients may be more receptive to physical activity interventions as the negative effects of chemotherapy begin to resolve, and therefore, may benefit from physical activity interventions. Results suggest that a low-cost home-based physical activity intervention with counselling and telephone support can improve the health and HRQoL of breast cancer survivors, which may in turn potentially reduce risk of breast cancer and cardiovascular disease-related mortality. Given the encouraging results and its highly portable and feasible nature, our intervention represents a promising tool for use in health and community settings to benefit large numbers of breast cancer survivors. The current project supports the inclusion of physical activity promotion as an integral component for the management and care of breast cancer survivors.

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