Dissertations / Theses on the topic 'Molecular conduction'
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Takeoka, Shinji. "Organization of molecular assemblies and ion conduction /." Electronic version of summary, 1991. http://www.wul.waseda.ac.jp/gakui/gaiyo/1668.pdf.
Full textHong, Daomin. "Kinetic model of heat conduction in molecular gases." Thesis, University of Sheffield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286969.
Full textRospigliosi, Alessandro. "Improving the conduction of DNA by molecular synthesis." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613839.
Full textStires, John C. "Charge transfer complexes in molecular electronics : approaching metallic conduction /." Diss., Connect to a 24 p. preview or request complete full text in PDF formate. Access restricted to UC campuses, 2007. http://wwwlib.umi.com/cr/ucsd/fullcit?p3250672.
Full textMacrae, Calum Archibald. "The molecular genetics of conduction disease and dilated cardiomyopathy." Thesis, St George's, University of London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408006.
Full textWang, Yi Jenny. "Equilibrium molecular dynamics study of heat conduction in octane." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/97858.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (pages 73-79).
Fluids are important components in heat transfer systems. Understanding heat conduction in liquids at the atomic level would allow better design of liquids with specific heat transfer properties. However, heat transfer in molecular chain liquids is a complex interplay between heat transfer within a molecule and between molecules. This thesis studies the contribution of each type of atomic interaction to the bulk heat transfer in liquid octane to further the understanding of thermal transport between and within chain molecules in a liquid. The Green-Kubo formula is used to calculate thermal conductivity of liquid octane from equilibrium molecular dynamics, and the total thermal conductivity is split into effective thermal conductivities for the different types of atomic interactions in the system. It is shown that the short carbon backbone of octane does not dominate thermal transport within the system. Instead, the thermal resistance within a molecule is about the same as the resistance between molecules.
by Yi Jenny Wang.
S.M.
Gwan, Jean-Fang. "The molecular mechanism of multi-ion conduction in K+ channels." [S.l.] : [s.n.], 2007. http://deposit.ddb.de/cgi-bin/dokserv?idn=983151253.
Full textSams, Craig A. "Electronic conduction in elongated molecular dyads containing a constrained bridge." Thesis, University of Newcastle Upon Tyne, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407639.
Full textRathjens, Franziska Sophie [Verfasser]. "Molecular mechanisms of TBX5-related conduction disorders / Franziska Sophie Rathjens." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2021. http://d-nb.info/1240161026/34.
Full textZachariah, Manesh. "Electronic & ionic conduction & correlated dielectric relaxations in molecular solids." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/404446.
Full textEl estudio de los materiales cristalinos juega un papel destacado en la física del estado sólido. Sin embargo, los materiales desordenados son más abundantes en la naturaleza que los cristalinos y, además, muchas de las aplicaciones prácticas utilizan materiales que son débilmente o fuertemente desordenados, como vidrios, líquidos, cristales plásticos, cristales moleculares, polímeros, o cristales líquidos. Desde un punto de vista fundamental, aún carecemos de una comprensión de de los materiales desordenados y de la transición vítrea: la comprensión de las propiedades asociadas desorden requiere el uso de conceptos que se alejan de los aplicables al estado cristalino. Desde una perspectiva aplicada, la investigación en los sólidos desordenados está promovida por la importancia tecnológica de estos materiales en la vida cotidiana. Los sólidos desordenados pueden conducir electricidad por transporte de electrones o de iones. En el primer caso, los materiales desordenados muestran menor conductividad que sus respectivas fases cristalinas, debido a la localización de los electrones de conducción por la existencia de desorden, que da lugar a saltos de electrones como principal mecanismo de transporte de carga. Por otro lado, el mismo desorden puede permitir la difusión de iones a través de intersticios; la conductividad iónica de materiales desordenados es más alta que sus fases homólogas cristalinas. Esta tesis presenta un estudio experimental de la conducción eléctrica y de la dinámica molecular de sólidos moleculares formados por derivados de fullereno (C60Br6, C60(ONa)24) o por moléculas con dos grupos nitrilos (succinonitrila (C2H4(CN)2), glutaronitrila (C3H6 (CN)2)). Estos materiales presentan, según el caso, conducción electrónica, protónica, o iónica. La tesis analiza los diferentes tipos de conducción de carga en materiales moleculares así como los procesos físicos relacionados, tales como las relajaciones de carga espacial. En el material C60Br6 observamos conducción electrónica tipo n y un comportamiento de fase no trivial. La dependencia de la conductividad con la temperatura está de acuerdo con el modelo de salto de rango variable (VRH). El C60(ONa)24 tiene un comportamiento de fase aún más rico. Se sintetiza como un hidrato policristalino, y se puede obtener como material puro por calentamiento. Mientras que el material puro es un semiconductor de tipo n, su exposición a una atmósfera húmeda aumenta la conductividad de forma dramática debido al transporte de carga a través de las capas de hidratación, lo que probablemente se debe a un mecanismo de intercambio de protones como en el agua pura o en el hielo. La conductividad del hidrato depende fuertemente de la temperatura en el proceso de deshidratación. Ambas formas, pura e hidratada, muestran un proceso dinámico asociado a la acumulación de electrones en los límites de grano. La presencia de agua tiene un fuerte impacto en tal proceso. Por último se analizan la dinámica molecular y la conductividad iónica de cristales plásticos, en particular, de las aleaciones moleculares en fase plástica formadas entre la succinonitrila y la glutaronitrila. En las fases plásticas las moléculas ocupan los sitios cristalográficos de la red, pero se encuentran orientacionalmente desordenadas. Se demuestra que las aleaciones succinonitrila-glutaronitrila son los primeros cristales plásticos que se conocen en los que existe una correlación perfecta entre la corriente de iones y la dinámica reorientational de las moléculas en los sitios cristalográficos. El dopaje de las aleaciones con sales de Li aumenta la conductividad pero destruye la correlación anterior, lo que indica que la correlación sólo es válida cuando el transporte de carga está dominado por la difusión de iones moleculares. Tal correlación puede ser consecuencia de una correlación entre las escalas de tiempo de rotación y de difusión.
Pugh, Nicholas. "Molecular biological investigation of the conduction pathway of the ryanodine receptor." Thesis, Imperial College London, 2003. http://hdl.handle.net/10044/1/8879.
Full textHenry, Asegun Sekou Famake. "Molecular dynamics analysis of spectral characteristics of phonon heat conduction in silicon." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/36233.
Full textIncludes bibliographical references (p. 91-95).
Due to the technological significance of silicon, its heat conduction mechanisms have been studied extensively. However, there have been some lingering questions surrounding the phonon mean free path and importance of different polarizations. This research investigates phonon transport in bulk crystalline silicon using molecular dynamics and lattice dynamics. The interactions are modeled with the environment dependent interatomic potential (EDIP), which was designed to represent the bulk phases of silicon. Temperature and phonon frequency dependent relaxation times are extracted from the MD simulations and used to generate a detailed picture of phonon transport. It is found that longitudinal acoustic phonons have the highest contribution to thermal conductivity and that the phonon mean free path varies by orders of magnitude with respect to the phonon spectra. For relaxation times, we observe moderate anisotropy and good agreement with the frequency dependence predicted by scattering theories. We also find that phonons with mean free paths between .1 and 10 micron are responsible for 50% of the thermal conduction, while phonons with wavelengths less than 10 nanometers make up 80%.
by Asegun Sekou Famake Henry.
S.M.
Tempatarachoke, Pisut Physical Environmental & Mathematical Sciences Australian Defence Force Academy UNSW. "Thermal conduction in the Fermi-Pasta-Ulam model." Awarded by:University of New South Wales - Australian Defence Force Academy. School of Physical, Environmental and Mathematical Sciences, 2005. http://handle.unsw.edu.au/1959.4/38684.
Full textMarrocchelli, Dario. "Studying the conduction mechanism of stabilised zirconias by means of molecular dynamics simulations." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/4631.
Full textHenry, Asegun Sekou Famake. "1D-to-3D transition of photon heat conduction in polyethylene using molecular dynamics simulations." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/49755.
Full textIncludes bibliographical references (p. 115-119).
Experiments have demonstrated that the mechanical stretching of bulk polyethylene can increase its thermal conductivity by more than two orders of magnitude, from 0.35 W/mK to over 40W/mK, which is comparable to steel. This strong effect is believed to arise from the increased alignment of the constituent polymer chains, which are thought to have very high thermal conductivity. Although it is well established that bulk polymers have low thermal conductivity, these experiments suggest that cheap, high thermal conductivity polymer materials can be engineered. This type of advancement may provide a much cheaper alternative to the conventional metal-based heat transfer materials that are used today. In order to quantify upper limits on the thermal conductivity of polyethylene, we examine the underlying phonon (lattice wave) transport using molecular dynamics simulations. We first show that the thermal conductivity of individual polyethylene chains is high, and can actually diverge (approach infinity) in some cases. We then discuss how the high thermal conductivity of individual chains is reduced by the presence of additional chains, through van der Waals chain-chain interactions. These intermolecular interactions give rise to both a 2D planar lattice structure and a 3D bulk lattice structure, which allows for the observation of an interesting 1D-to-3D transition in phonon transport.
(cont.) For most crystalline nanostructures, the thermal conductivity decreases with decreasing crystal size from an enhanced boundary scattering of phonons. In the case of polyethylene, however, the intermolecular chain-chain interactions increase phonon-phonon scattering along each chain and actually result in the opposite trend, where the thermal conductivity increases with decreasing crystal size. The results provide important fundamental insight into phonon-phonon interactions and will also aid in the design and structural optimization of high thermal conductivity polymers.
by Asegun Sekou Famake Henry
Ph.D.
El, Zein Loubna. "Étude des voies de conduction cardiaque : identification des gènes spécifiquement exprimés et impliqués dans des troubles de conduction." Phd thesis, Université Claude Bernard - Lyon I, 2003. http://tel.archives-ouvertes.fr/tel-00521428.
Full textBrieuc, Fabien. "Modélisation et simulation des effets quantiques en dynamique moléculaire : application à l'étude de la conduction protonique." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLC060.
Full textThis thesis deals with the study of quantum effects in molecular dynamics (MD). MD is a powerful numerical method to investigate the properties of condensed matter systems. However, since the method is based on classical mechanics, quantum effects associated with the dynamics of the nuclei, such as zero-point energy or tunnelling, are not taken into account. These nuclear quantum effects can, however, play a major role in particular at low temperatures and/or in systems containing light atoms such as hydrogen. In these cases, a standard way to account for the quantum nature of the nuclei is to use path integral molecular dynamics (PIMD). This method provides exact quantum results however its high computational cost limits its range of applicability. The quantum thermal bath (QTB) method has been proposed as an alternative to PIMD. The QTB method is particularly appealing because of its computational cost that is equivalent to standard MD thus allowing to study large and complex systems.The first part of this thesis is devoted to the study of the QTB method. We have studied the behavior of the method in selected model systems in order to investigate its limitations. We have focused, in particular, on the zero-point energy leakage problem and found that increasing the friction coefficient of the QTB can significantly limit this problem. We also have developed another way to use the QTB method by combining it with PIMD. This combined QTB-PIMD method allows, in particular, to decrease the computational cost of standard PIMD simulations.In a second part, we have used these methods to study hydrogen conduction in perovskite materials. We have first investigated the impact of quantum effects on the diffusion of hydrogen in BaZrO3, a potential electrolyte material for hydrogen fuel cells. Since hydrogen is the lightest element, we expect quantum effects to have a significant impact on its dynamics. We find that quantum effects are indeed significant at low temperatures although their impact on the diffusion remains low at the typical working temperatures of hydrogen fuel cells. Finally, we have investigated the diffusion mechanisms of hydrogen in GdBaCo2O5.5. We evidence that the diffusion is anisotropic in this material and two main diffusion mechanisms
Nguyen, Thi-Hong-Minh. "Functional defects and molecular mechanisms of Left Ventricular Noncompaction (LVNC) in Nkx2.5 mutant mice." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4039.
Full textLVNC is a rare cardiomyopathy, characterized by hypertrabeculation and deep trabecular recesses in the left ventricle. It is still unclear whether LVNC results from a defect occurring during cardiac development. One hypothesis to consider is that the severity of LVNC depends on which embryonic stage the arrest of myocardial compaction occurs. Our aim was to study the pathological evolution of LVNC by characterizing functional defects and identifying molecular mechanisms in mouse models with abnormal ventricular trabeculae development. To establish a LVNC mouse model, we generated specific Nkx2.5 conditional knockout mice to delete Nkx2.5 allele in atria and trabecular derived cardiomyocytes at embryonic stages when trabeculae arise (at around E10), or start to compact (at around E14), or at neonatal stages (after birth) when the heart is almost finish compaction step. After all, we were successful in generating several LVNC mouse models by the conditional deletion of Nkx2.5 transcription factor in atria and trabecular derived cardiomyocytes. These mouse models are suitable for studying LVNC pathology. We also confirmed the hypothesis that the severity of LVNC depends on stages when disturbances in the trabecular development occur. Hypertrabeculation, cardiac conduction defects, decreased ejection fraction, and existence of fibrosis are robustly observed following deletion at E10.5/11.5 meaning that the deletion at early stage of trabecular development causes the most severe pathological phenotype of LVNC. There had been just a few publications showing inflammation in LVNC heart, which could be a very good finding for future researches
Shen, Kuan-Hsuan. "Modeling ion conduction through salt-doped polymers: Morphology, ion solvation, and ion correlations." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1595422569403378.
Full textLeoni, Stefano. "Theoretical and Experimental Investigations on Solid State Reactions: Phase Transition Mechanisms, Ionic Conduction, Domain Formation and Interface Reactivity." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-79219.
Full textMendonça, Mileo Paulo Graziane. "Computational exploration of water adsorption and proton conduction in porous materials." Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTS142/document.
Full textThe objective of this PhD thesis was to gain insight into the proton dynamics and water adsorption mechanisms in novel porous materials that have been identified experimentally as promising candidates for low temperature proton conduction and adsorption-based heat reallocation-related applications. This was achieved by combining advanced computational tools at the electronic (Density Functional Theory) and atomic (force field_based Monte Carlo and Molecular Dynamics) levels to (i) reveal the water-assisted proton migration pathway through the pores of the hybrid metal organic frameworks MIL-163(Zr) and KAUST-7’and the inorganic phosphonate TiIVTiIV(HPO4)4 materials at the origin of their outstanding proton conduction performances and (ii) explain the water adsorption behaviors of a series of metal organic frameworks CUK-1(Me), MOF-801(Zr) and MIL-100(Fe) that can be tuned by changing the nature of the metal center, creating defects and incorporating coordinatively unsaturated sites. Such a fundamental understanding is expected to pave the way towards a more efficient development of materials for the two explored applications
Atzori, Matteo. "Anilate-based Functional Molecular Materials with Conducting and Magnetic Properties." Thesis, Angers, 2015. http://www.theses.fr/2015ANGE0009/document.
Full textThis work explores the potential of anilate-based ligands in the synthesis of new rational designed functional molecular materials exhibiting improved magnetic and conducting properties. Anilates, namely 3,6-disubstitued 2,5-dihyroxy-1,4- benzoquinones in their dianionic form, have been selected as ligands since their electronic/structural features, coordination modes and ability to mediate magnetic exchange interactions between coordinated metal centers make them potential candidates for the preparation of theabove-mentioned materials. Various anilate derivatives have been used for the preparation of a family of rationally designed tris-chelated octahedral paramagnetic metal complexes of general formula [MIII(X2An)3]3- (MIII = Cr, Fe; X = Cl, Br, I, H, Cl/CN, An = C6O4 2- = anilate). These paramagnetic metal complexes have been thoroughly characterized and used, in turn, as molecular building blocks for the preparation of i) a family of molecule-based magnets, where subtle changes in the nature of the substituents on the anilate moiety were employed as “adjusting screws” in tuning the magnitude of the magnetic interaction between the metals, and thus, the magnetic properties, ii) hybrid paramagnetic molecular conductors in combination with the BEDT-TTF organic donor, iii) a complete series of isostructural chiral molecular conductors obtained by combining the TMBEDT- TTF chiral donor with 2D heterobimetallic anionic layers obtained in situ by the self-assembling of tris (chloranilato)ferrate(III) metal complexes and potassium cations.Moreover, novel anilate derivatives showing electroactive and luminescent properties have been further synthesized, highlighting the versatility of the anilate moiety to be functionalized with suitable substituents carrying selected physical properties
Bedouret, Laura. "Modélisation théorique et expérimentale du mécanisme de conduction protonique dans un clathrate hydrate ionique." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-00821882.
Full textSouto, Salom Manuel. "Multifunctional Materials based on TTFPTM dyads: towards new Molecular Switches, Conductors and Rectifiers." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/393986.
Full textThis Thesis is focused on the design, synthesis and characterization of new multifunctional molecular materials based on donor-acceptor (D-A) dyads formed by the electron-donor tetrathiafulvalene (TTF) unit linked to the electron-acceptor polychlorotriphenylmethyl (PTM) radical moiety through different -conjugated bridges. These compounds can exhibit interesting physical properties such bistability and nonlinear optical properties in solution, conductivity in the solid state or electrical rectification when anchored on surfaces. Thus, these systems could find potential applications in the field of molecular electronics as switches, conductors or rectifiers. In the first part of the Thesis, we have studied the bistability phenomenon in solution of a D-A dyad based on a PTM radical linked to a TTF moiety through a vinyelene bridge. This system exhibited a temperature-induced switching between diamagnetic dimers at room temperature and paramagnetic monomers at high temperature. The two different states showed different optical and magnetic properties when using the temperature as external input. On the other hand, we have also reported the A-D-A diradical triad based on two PTM radical subunits connected through a TTF-vinylene bridge that can reversibly modify the optical, electronic and magnetic properties by one-electron reduction and oxidation in CH2Cl2 solution. The modification of electron delocalization and magnetic coupling was observed when the charged species were generated and the changes were rationalized by theoretical calculations. In the second part of the Thesis, we have reported the synthesis and characterization of different TTF--PTM dyad derivatives increasing the number of vinylene units between the D and A moieties. We have studied the intramolecular charge transfer and non-linear optical (NLO) properties in solution and their dependence on the open-shell structure as well as on the bridge length for this family of compounds. In the third part of the Thesis, we have studied self-assembled architectures in the solid state of a new D-A dyad based on a PTM radical linked to a TTF moiety through a -phenyl-pyrrole bridge. The crystal structure showed an interesting supramolecular arrangement with segregated donor and acceptor units. Moreover, we reported the appearance of conductivity in single crystals of the same system when increasing the pressure. The semiconducting behavior at high pressures has been attributed to the enhanced intermolecular interactions and charge delocalization due to incorporation of TTF units which force the formation of close packed stacks of molecules. Finally in the last part of the Thesis, we have reported a new TTF-PTM dyad that was functionalized with a disulfide group in order to prepare self-assembled monolayers (SAMs) on gold. These SAMs were fully characterized by different spectroscopic techniques in order to study the electronic structure of the system. Moreover, charge transport measurements through the SAMs were performed in order to evaluate the possible rectification behavior.
Cafe, Peter F. "Towards reliable contacts of molecular electronic devices to gold electrodes." Thesis, The University of Sydney, 2008. http://hdl.handle.net/2123/3870.
Full textCafe, Peter F. "Towards reliable contacts of molecular electronic devices to gold electrodes." University of Sydney, 2008. http://hdl.handle.net/2123/3870.
Full textSYNOPSIS OF THIS THESIS The aim of this thesis is to more fully understand and explain the binding mechanism of organic molecules to the Au(111) surface and to explore the conduction of such molecules. It consists of five discreet chapters connected to each other by the central theme of “The Single Molecule Device: Conductance and Binding”. There is a deliberate concentration on azine linkers, in particular those with a 1,10-phenanthroline-type bidentate configuration at each end. This linker unit is called a “molecular alligator clip” and is investigated as an alternative to the thiol linker unit more commonly used. Chapter 1 places the work in the broad context of Molecular Electronics and establishes the need for this research. In Chapter 2 the multiple break-junction technique (using a Scanning Tunnelling Microscope or similar device) was used to investigate the conductance of various molecules with azine linkers. A major finding of those experiments is that solvent interactions are a key factor in the conductance signal of particular molecules. Some solvents interfere with the molecule’s interaction with and attachment to the gold electrodes. One indicator of the degree of this interference is the extent of the enhancement or otherwise of the gold quantized conduction peak at 1.0 G0. Below 1.0 G0 a broad range for which the molecule enhances conduction indicates that solvent interactions contribute to a variety of structures which could bridge the electrodes, each with their own specific conductance value. The use of histograms with a Log10 scale for conductance proved useful for observing broad range features. vi Another factor which affects the conductance signal is the geometric alignment of the molecule (or the molecule-solvent structure) to the gold electrode, and the molecular alignment is explored in Chapters 3 for 1,10-phenanthroline (PHEN) and Chapter 4 for thiols. In Chapter 3 STM images, electrochemistry, and Density Functional Theory (DFT) are used to determine 1,10-phenanthroline (PHEN) structures on the Au(111) surface. It is established that PHEN binds in two modes, a physisorbed state and a chemisorbed state. The chemisorbed state is more stable and involves the extraction of gold from the bulk to form adatom-PHEN entities which are highly mobile on the gold surface. Surface pitting is viewed as evidential of the formation of the adatom-molecule entities. DFT calculations in this chapter were performed by Ante Bilic and Jeffery Reimers. The conclusions to Chapter 3 implicate the adatom as a binding mode of thiols to gold and this is explored in Chapter 4 by a timely review of nascent research in the field. The adatom motif is identified as the major binding structure for thiol terminated molecules to gold, using the explanation of surface pitting in Chapter 3 as major evidence and substantiated by emergent literature, both experimental and theoretical. Furthermore, the effect of this binding mode on conductance is explored and structures relevant to the break-junction experiment of Chapter 2 are identified and their conductance values compared. Finally, as a result of researching extensive reports of molecular conductance values, and having attempted the same, a simple method for predicting the conductance of single molecules is presented based upon the tunneling conductance formula.
Saadat, Abdelkader. "Etude de la mobilite moleculaire du collagene par courants thermostimules : modelisation du vieillissement cutane." Toulouse 3, 1988. http://www.theses.fr/1988TOU30178.
Full textMabboux, Pierre-Yves. "Relaxation nucléaire dans les polymères conducteurs : application à l'étude de la conduction microscopique et développements théoriques." Grenoble INPG, 1996. http://www.theses.fr/1996INPG0172.
Full textXu, Degao. "Atomic Force Microscope Conductivity Measurements of Single Ferritin Molecules." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd645.pdf.
Full textJohnson, Christopher M. "Investigating the Slow Axonal Transport of Neurofilaments: A Precursor for Optimal Neuronal Signaling." Ohio University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1452018547.
Full textPIMENTA, MARCOS ASSUNCAO. "Transitions de phase a haute temperature et conduction ionique dans likso:(4) et composes apparentes." Orléans, 1987. http://www.theses.fr/1987ORLE2045.
Full textConstantinidès-Mégret, Colette. "Etude de la structure physique de l'elastine par spectroscopies thermostimulees (aed, cts)." Toulouse 3, 1988. http://www.theses.fr/1988TOU30128.
Full textPETIT, PIERRE. "Magnetisme et proprietes de conduction des derives cristallins et liquides cristallins de la bisphtalocyanine de lutecium : effet de dimensionnalite." Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13163.
Full textWhitehead, Roger James. "Highly conducting molecular crystals." Thesis, University of Nottingham, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329892.
Full textFernandez, Pedro. "A candidate and novel gene search to identify the PFHBII-causative gene." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/36913.
Full textBibliography
ENGLISH ABSTRACT: Heart failure due to cardiomyopathy or cardiac conduction disease is a major cause of mortality and morbidity in both developed and developing countries. Although defined as separate clinical entities, inherited forms of cardiomyopathies and cardiac conduction disorders have been identified that present with overlapping clinical features and/or have common molecular aetiologies. The objective of the present study was to identify the molecular cause of progressive familial heart block type II (PFHBII), an inherited cardiac conduction disorder that segregates in a South African Caucasian Afrikaner family (Brink and Torrington, 1977). The availability of family data tracing the segregation of PFHBII meant that linkage analysis could be employed to identify the chromosomal location of the disease-causative gene. Human Genome Project (HGP) databases have provided additional resources to facilitate the identification of positional candidate genes. Clinical examinations were performed on individuals of the PFHBII-affected family, and, where available, clinical records of subjects examined in a previous study by Brink and Torrington (1977) were re-assessed. Retrospective data suggested redefining the classification of PFHBII. Subsequently, linkage analysis was used to test described dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM) and cardiac conduction-causative loci on chromosomes 1, 2, 3, 6, 7, 9, 11, 14, 15 and 19 for their involvement in the development of PFHBII. Once a locus was mapped, bioinformatics tools were applied to identify and prioritise positional candidate genes for mutation screening. The retrospective and prospective clinical study redefined PFHBII as a cardiac conduction and DCM-associated disorder and simultaneously allowed more family members to be traced. Fortuitously, candidate loci linkage analysis mapped the PFHBII locus to chromosome 1q32, to a region that overlapped a previously described DCM-associated disorder (CMD1D), by the generation of a maximum pairwise lod score of 3.13 at D1S3753 (theta [θ]=0.0) and a maximum multipoint lod score of 3.7 between D1S3753 and D1S414. However, genetic fine mapping and haplotype analysis placed the PFHBII-causative locus distal to the CMD1D locus, within a 3.9 centimorgan (cM) interval on chromosome 1q32.2-q32.3, telomeric of D1S70 and centromeric of D1S505. Bioinformatics analyses prioritised seven candidate genes for mutation analysis, namely, a gene encoding a potassium channel (KCNH1), an extracellular matrix protein (LAMB3), a protein phosphatase (PPP2R5A), an adapter protein that interacts with a cytoskeletal protein (T3JAM), a putative acyltransferase (KIAA0205) and two genes encoding proteins possibly involved in energy homeostasis (RAMP and VWS59). The PFHBII-causative mutation was not identified, although single sequence variations were identified in four of the seven candidate genes that were screened. Although the molecular aetiology was not established, the present study defined the underlying involvement of DCM in the pathogenesis of PFHBII. The new clinical classification of PFHBII has been published (Fernandez et al., 2004) and should lead to tracing more affected individuals in South Africa or elsewhere. The identification of a novel disease-causative locus may point toward the future identification of a new DCM-associated aetiology, which, in turn, might provide insights towards understanding the associated molecular pathophysiologies of heart failure.
AFRIKAANSE OPSOMMING: Hartversaking as gevolg van kardiomiopatie of kardiale geleidingsiekte is ‘n hoof-oorsaak van mortaliteit and morbiditeit in beide ontwikkelde en ontwikkelende lande. Alhoewel gedefinieer as verskillende kliniese entiteite is oorerflike vorms van kardiomiopatie en kardiale geleidingsstoornisse geïdentifiseer met oorvleuelende kliniese eienskappe en/of molukulêre oorsake. Die doelwit van hierdie studie was om die molukulêre oorsaak van progressiewe familiële hartblok tipe II (PFHBII), ‘n oorerflike kardiale geleidingsstoornis, wat in ‘n Suid-Afrikaanse Kaukasiër familie segregeer (Brink en Torrington, 1977), te identifiseer. Die beskikbaarheid van familie data, beteken dat koppelingsanalise gebruik kan word om die chromosomale posisie van die siekte-veroorsakende geen te identifiseer. Menslike Genoom Projek (MGP) databanke het addisionele hulpbronne beskikbaar gestel om die identifikasie van posisionele kandidaat gene te vergemaklik. Kliniese ondersoeke is uitgevoer op PFHBII-geaffekteerde familielede, en waar beskikbaar is kliniese rekords van persone, wat in ‘n vorige studie deur Brink en Torrington (1977) geassesseer was, herontleed. Retrospektiewe data-analise het die kliniese herdefinisie van PFHBII voorgestel. Daarna is koppelingsanalise gebruik om dilateerde kardiomiopatie (DKM), hipertrofiese kardiomiopatie (HKM) en kardiale geleidingssiekte-veroorsakende loki op chromosoom 1, 2, 3, 6, 7, 9, 11, 14, 15 en 19 te ondersoek vir hul moontlike bydrae tot die ontwikkeling van PFHBII. Toe die lokus gekarteer was, is bioinformatiese ondersoeke gebruik om posisionele kandidaat gene te identifiseer en prioritiseer vir mutasie analise. Die retrospektiewe en prospektiewe kliniese ondersoek het PFHBII herdefinieer as ‘n geleidingsstoornis en DKM-verbonde siekte, en terselfde tyd het dit gelei tot die opsporing van nog familielede. Toevallig het kandidaat loki-analise die PFHBII lokus op chromosoom 1q32 gekarteer, na ‘n gebied wat met ‘n voorheen-beskyfde DKM-verbonde stoornis (CMD1D) oorvleuel, met die opwekking van ‘n makisimum paargewyse lod-getal van 3.13 by D1S3753 (theta [θ] = 0.0) en ‘n maksimum multipunt lod-getal van 3.7 tussen D1S3753 en D1S414. Genetiese fynkartering en haplotipe-analise het die PFHBII-veroorsakende lokus afwaards van die CMD1D lokus geplaas, in ‘n 3.9 centimorgan (cM) gebied op chromosoom 1q32.2-q32.3, telomeries van D1S70 en sentromeries van D1S505. Bioinformatiese analise het daarnatoe gelei dat sewe kandidaat gene vir mutasie analise geprioritiseerd is, naamlik, gene wat onderskeidelik ‘n kalium kanaal (KCNH1), ‘n ekstrasellulêre matriksproteïen (LAMB3), ‘n proteïen fosfatase (PPP2R5A), ‘n aansluiter proteïen wat met ‘n sitoskilet proteïen bind (T3JAM), ‘n asieltansferase (KIAA0205) en twee gene moontlik betrokke in energie homeostase (RAMP en VWS59) enkodeer. Die PFHBII-veroorsakende geen is nie geïdentifiseer nie, alhoewel enkele volgorde-wisselings geïdentifiseer is in vier van die sewe geanaliseerde kandidaat gene. Alhowel die molekulêre oorsaak van die siekte nie vasgestel is nie, het die huidige studie die onderliggende betrokkenheid van DKM in die pathogenese van PFHBII gedefinieer. Die nuwe kliniese klassifikasie van PFHBII is gepubiliseer (Fernandez et al., 2004) en sal lei tot die identifisering van nog geaffekteerde persone in Suid Afrika of in ander lande. Die identifikasie van ‘n nuwe siekte-verbonde lokus mag lei tot die toekomstige identifikasie van ‘n nuwe DKM-verbonde genetiese oorsaak wat, opsig self, dalk insig kan gee in die molekulêre patofisiologie van hartversaking.
Ashoka, Sahadevan Suchithra. "Anilate-based molecular building blocks for metal-organic frameworks and molecular conductors Conducting Anilate-Based Mixed-Valence Fe(II)Fe(III) Coordination Polymer: Small-Polaron Hopping Model for Oxalate-Type Fe(II)Fe(III) 2D Networks Nanosheets of Two-Dimensional Neutral Coordination Polymers Based on Near-Infrared-Emitting Lanthanides and a Chlorocyananilate Ligand." Thesis, Angers, 2019. http://bu.univ-angers.fr/Contact.
Full textThis work reports on the design, synthesis and characterization of novel anilate-based functional molecular materials showing luminescent, magnetic and/or conducting properties. The family of anilate ligands comprises several derivatives obtained by introducing various substituents (H, F, Cl, Br, I, CN, etc.) at the 3 and 6 positions of the common 2,5-dihydroxy-1,4-benzoquinone framework. Among the anilate ligands, the only known heterosubstituted anilate with Cl/CN substituents at the 3,6 positions, ClCNAn2-, have been selected for preparing a novel family of 2D layered coordination polymers (2D CP) with both 3d metal ions and 4f lanthanide ions, through a general and straightforward synthetic strategy. i) Mixed-valence FeIIFeIII 2D CP, formulated as [TAG][FeIIFeIII(ClCNAn)3], containing, the tris(amino)-guanidinium (TAG) cation for the first time in such 2D networks has been synthesized and thoroughly characterized. ii) 2D CPs based on NIR-emitting lanthanides (YbIII, NdIII, ErIII) and the ClCNAn2- ligand, have been prepared and characterized. These layered compounds were exfoliated to nanosheets, by sonication-assisted solution synthesis. Time-resolved photoluminescence studies performed on both the bulk and nanosheets are also highlighted. iii) Novel family of heteroleptic 2D CPs based on NIR-emitting lanthanides and mixed ligands (ClCNAn2- and carboxylate ligands (DOBDC and F4-BDC)), were prepared and characterized. vi) Novel family of 2D CPs based on DyIII and ClCNAn2- were prepared in order to investigate their magnetic properties. v) Furthermore, the ability of anilate ligands to work as components of BEDT-TTF- based molecular conductors have been demonstrated through the synthesis, via electrocrystallization technique. vi) П-d hybrid multifunctional paramagnetic molecular conductors BEDT-TTF and [Fe(ClCNAn)3]3-) were also studied
Anquetil, Patrick A. T. (Patrick Armand T. ). 1973. "Large contraction conducting polymer molecular actuators." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/30349.
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The development of powerful and efficient artificial muscles that mimic Nature will profoundly affect engineering sciences including robotics and prosthetics, propulsion systems, and microelectromechanical systems (MEMS). Biological systems driven by muscle out-perform human-engineered systems in many key aspects. For example, muscle endows animals with a level of dexterity and speed that has yet to be emulated by even the most complex robotic system to date. Conducting polymers were chosen for research as actuators, based on a review of the relevant properties of all known actuators and active materials. Key features of conducting polymer actuators include low drive voltages (1 - 2 V) and high active strength (10 - 40 MPa) but moderate active strains (2 %). Active strains of 20 %, which human skeletal muscle is capable of, are desirable for applications in life-like robotics, artificial prostheses or medical devices. This thesis focuses on two approaches to create large contraction in conducting polymer actuators. The first strategy utilizes polypyrrole (PPy), a conducting polymer actuator material that contracts and expands based on a bulk ion swelling mechanism. Optimization of the polymer activation environment via room temperature ionic liquids enables PPy actuators to generate large contractions (16.3 % recoverable strain at 2.5 MPa, 21 % max) at slow speeds (0.4 %/s). In addition, cycle life can reach 10⁵ cycles without significant polymer degradation. This thesis presents an in-depth characterization of the behavior of polypyrrole actuators in room temperature 1-butyl-3-methyl imidazolium tetrafluoroborate liquid salt electrolyte.
(cont.) The characterization includes the assessment of passive and electroactive mechanical properties as well as electrical and morphological properties. Using Nature's actin-myosin molecular engine as a source of inspiration, the second approach uses molecular mechanisms to create motion. In this bottom-up approach molecules are rationally designed from the molecular level for specific actuation properties. Such active molecular building blocks include shape changing, load bearing, passively deformable or hinge-like molecular elements. Several novel materials based on contractile molecular design were synthesized and their active properties characterized.
by Patrick A.T. Anquetil.
Ph.D.
Consiglio, Armando. "Molecular dynamics simulations of conducting polymer nanocomposites." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18454/.
Full textElias, Watheq Zako. "Calculation of the electrical conduction of molecules and nanowires." Thesis, Cardiff University, 2014. http://orca.cf.ac.uk/60045/.
Full textDempsey, Phillip James Francis. "Towards proton and electron conducting porphyrin molecular films." Thesis, Brunel University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363199.
Full textHout, Jamal el. "Etude des mouvements moleculaires dans le polyacetylene par courant thermostimule." Toulouse 3, 1986. http://www.theses.fr/1986TOU30061.
Full textRatter, Kitti. "Epitaxial Rhenium, un supraconducteur en limite propre pour des Qbits supraconducteurs." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY074/document.
Full textThe epitaxial growth condition and the superconducting properties of nanostructured devices made of rhenium (superconducting below T=1.7 K) on sapphire were explored. Epitaxial growth of rhenium thin films onto a single crystal α-Al2O3(001) substrate was realised using molecular beam epitaxy. The cleanness of the substrate was verified using XPS, and the growth of rhenium was monitored using RHEED. The orientations of the two crystals are (0001)Al2O3//(0001)Re and <2110>Al2O3//<0110>Re, which was confirmed using X-ray diffraction. The in-plane misfit between the lattices is -0.43% at room temperature, which allows us to estimate the critical thickness of rhenium to be between 10 nm and 15 nm.For deposition, rhenium was heated using an electron beam. Substrates were heated during growth using either a Joule-heated W filament located behind the sample or electron bombardment. Generally deposition temperatures of 800◦C and 900◦C gave reproducible results.The effect of deposition temperature was studied on samples that had the same thickness but were deposited at different temperatures. Three thickness groups were selected: 25 nm, 50 nm and 100 nm. Every sample was dominated by the (001) epitaxial orientation. Orientations (110), (100), (101) were present, but their intensities were small and decreased with increasing deposition temperature. AFM imaging was used to observe the morphology of the films. The 25 nm thick films were decorated with grains. The diameter of the grains (∼ 50 nm) did not vary significantly on the 25 nm thick sample, however, they became more uniform with increasing deposition temperature, and the surface became smoother. On the 50 nm and 100 nm thick films spirals and holes can be observed. Diameter of spirals on the 50 nm thick film increased from 100 nm to 500 nm when the temperature of the deposition was increased from 800◦C to 900◦C. XRD rocking curves measured on all samples got narrower with increasing deposition temperatures, indicating lower mosaicity of the (001) crystals. High-resolution θ-2θ scans evidenced a disorder in the 50 nm thick film, corresponding to strain values in the range of 0.01. Deposition temperature of 1000◦C lead to the dewetting of a 50 nm thick sample, islands with atomically flat surfaces were formed.The frequently observed spirals are most likely the result of screw dislocations. The origin of the holes that accompany the spirals is a dewetting process that starts when the thickness of the film reaches ~10 nm. We quantified the temperature evolution of the film during growth taking into account emission, reflection and transmission between all surfaces. This thermal model confirmed that the temperature of the film increases as the thickness of the rhenium film grows. The dewetting was studied using Mullins’ theory of thermal grooving. A surface diffusion coefficient of 4E−12 cm2/s was obtained, which is consistent with the observed dimensions of the surface topography.Wires with widths ranging from 100 nm to 3 μm and SQUIDs were fabricated from the rhenium films. Transport measurements confirmed that the lithography process does not affect the superconducting properties of rhenium. Critical temperatures between 1.43 K and 1.96 K were measured. We could correlate the superconducting transition temperature with the topography and the crystallinity of the films. Mean free path of electrons, and the superconducting coherence length were obtained, for two of the films both mean free path and effective coherence length were over 100 nm. These two films were in the clean limit, but the fabricated wires were in the dirty limit.On one film SQUIDs of 1 um diameter with 50 nm and 20 nm wide nanobridges acting as Josephson junctions were fabricated. The SQUIDs were cooled down using a dilution refrigerator. Critical current oscillations were measured. The flux noise values obtained were as low as 2.6E−5 Φ0/Hz1/2
Musumeci, Chiara. "Supramolecular electronics : from molecular wires to (semi)conducting materials." Phd thesis, Université de Strasbourg, 2014. http://tel.archives-ouvertes.fr/tel-01038014.
Full textTiu, Brylee David Buada. "Conducting Polymers for Molecular Imprinting and Multi-component Patterning Applications." Case Western Reserve University School of Graduate Studies / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=case1449227860.
Full textDella, Pia Eduardo Antonio. "Single molecule conduction of engineered cytochrome b562 bonded to metallic electrodes." Thesis, Cardiff University, 2011. http://orca.cf.ac.uk/55082/.
Full textCheikh, Ibrahim Ajfane. "Synthèse des matériaux hybrides organiques inorganiques multifonctionnalisés." Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20067/document.
Full textThe aim of this work was focused on the structuration and the functionalization of organic-inorganic hybrid materials by the sol-gel process.The synthesis and characterization of new proton conductive membranes for fuel cell proton exchange membrane (PMFC), was prepared in the first part. Hybrid membranes based on polyethylene glycol highly functionalized with sulfonic acid have been synthesized and characterized through a physicochemical and proton conductivity. They have good mechanical properties, a sufficient chemical stability and a performant proton conductivity to be used as an electrolyte in fuel cell proton exchange membrane.In the second part, we have developed hybrid mesoporous materials with porous multifunctionalized in the presence of surfactant nonionic block copolymer (P123). Two probes were used for this study: the proton exchange capacity and the control of the growth of gold nanoparticles in the pores
Elmarhoumi, Nader M. "Novel Semi-Conductor Material Systems: Molecular Beam Epitaxial Growth and Characterization." Thesis, University of North Texas, 2013. https://digital.library.unt.edu/ark:/67531/metadc490047/.
Full textJones, Gareth. "Investigation of the electronic conduction of large molecules via semi-empirical electronic structure techniques." Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/42005/.
Full textTimpanaro, Salvatore. "Conductive properties and morphology of conjugated molecular materials studied by local probe techniques." Phd thesis, [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=974115991.
Full textNageshkar, Vishal Vinayak. "Enhancing the splitting efficiency of water molecules using conductive nanomaterials." Thesis, Wichita State University, 2013. http://hdl.handle.net/10057/10640.
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