Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 23 for “"2H-NMR"”.
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Molekulare Dynamik in binären Glasbildnern studiert mittels 31P- und 2H-NMR
… Anwendung der Kernspinresonanz-Spektroskopie (NMR) mit Methoden wie der Linienformanalyse, Messung des Stimulierte-Echo-Zerfalls, der zweidimensionalen (2D-) Spektren und der Spinrelaxation ermöglicht eine selektive Betrachtung der beiden Komponenten. Es werden Systeme untersucht, welche sich …
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A critical analysis of the 2H NMR data in chlorhexidine-containing model membranes
… the rapid molecular motions (on the NMR scale) in both the fatty acid chains of DMPC and in the saturated methylene bridge of CHX. The results are consistent with the known localization of CHX in the membrane determined by neutron scattering [1] and con rmed by molecular dynamics …
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Study of relaxation processes in simple glass formers by means of 2H NMR spectroscopy
… were investigated by means of multidimensional 2H NMR (solid echo and 2D spectra, stimulated echo decays, spin-lattice and spin-spin relaxation). We focused our attention on glass forming liquids that were composed of simple, rigid molecules in order to study the properties of the secondary …
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Secondary relaxation processes in neat and binary glass formers studied by 2H NMR spectroscopy
The present study employs various solid state 2H NMR techniques to elucidate glassy dynamics in plastic crystals and binary mixtures of glass forming substances. We focus on the Johari-Goldstein beta-process, which not only plays a key role for the understanding of glassy dynamics in neat systems, …
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Advancing characterization techniques for structure-property determination of in-situ lignocelluloses
… quadrupolar nuclear magnetic resonance (2H NMR) and rheo-infrared spectroscopy. A novel parallel-plate compressive-torsion DMA protocol is developed to analyze very small solvent-plasticized biomass specimens with or without mechanical integrity. The benefits and limitations of this …
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Rheo-NMR-Untersuchungen an lyotropen Systemen
… Hierfür wurde eine Miniatur-Scherzelle in einen NMR-Probenkopf integriert, so dass es möglich war durch Kombination aus Rheologie und 2H-NMR-Spektroskopie, der sogennaten Rheo-NMR, das Fließverhalten zu eruieren. Deformationsabhängig NMR-Experimente einer C10E3/Wasser-Mischung sind mit der …
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Synthesis and mechanistic studies on the monoamine oxidase (MAO) catalyzed oxidation of 1,4-disubstituted-1,2,3,6-tetrahydropyridines
… derivatives and have been characterized by 2H NMR in a chiral liquid crystal matrix. These enantiomers were used to determine the selectivity of the MAO-B catalyzed a C-H bond cleavage reaction leading to the dihydropyridinium metabolite MPDP+. Some of the cyclopropyl analogs of MPTP have …
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Solid-state NMR spectroscopy applied to model membranes: effects of polyunsaturated fatty acids
… (chol). Here the molecular organization of [2H31]-N-palmitoylsphingomyelin (PSM-d31) mixed with 1-palmitoyl-2-docosahexaenoylphosphatylcholine (PDPC) or 1-palmitoyl-2-oleoylphosphatidylcholine (POPC), as a monounsaturated control, and cholesterol (chol) (1:1:1 mol) in a model membrane was …
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Struktur und Dynamik mesomorpher Polysilane
… bis 200 MPa und 29Si- sowie 2H-Festkörper-NMR-Spektroskopie untersucht. Für die 2H-NMR-Spektroskopie wurden selektiv am ersten C-Atom der Alkylseitenketten deuteriummarkierte Polymere synthetisiert. <br> <br>Die NMR-Untersuchungen bei Normaldruck zeigen, daß Polysilane im …
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Thermotropic and lyotropic mesophases formed by some lithium soaps.
… microscopy (plus x-ray diffraction and 7Li NMR spectroscopy for the latter). Each soap exhibited a characteristic stepwise melting behaviour. In contrast to the oleate, both LiC[18] and LiPS formed high temperature liquid crystal phases (lamellar and reversed hexagonal structures …
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Magic angle spinning NMR applied to membrane protein 2D crystals : the structure and function of VDAC
… Angle Spinning Nuclear Magnetic Resonance (MAS NMR) to investigate the structure and function of the 32 kDa human integral membrane protein VDAC, the Voltage Dependent Anion Channel. Our results on VDAC have relied on a number of improvements in NMR methodology described in this thesis. These …
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Adsorption of phloretin to lipid layers
… into the hydrocarbon layer is unlikely. 2H NMR measurements with spherical unilamellar vesicles of headgroup-deuterated lipid showed changed quadrupolar splittings indicating the interaction between phloretin and headgroups of the lipids.
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A Physicochemical and Biophysical Investigation into the Role of Lysyl- Phosphatidylglycerol in the Membrane of Staphylococcus aureus under mild acidic conditions
… membrane lipid composition was quantified by 31P NMR. Monolayers and bilayers formed from S. aureus lipid extracts and synthetic lipid models were employed in investigations into the effects of low pH and CAMPs on membrane structure and physicochemical properties. The experimental techniques …
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Biotransformation of aromatic hydrocarbons and organic sulphides by fungi
… in a non-symmetrical transition state. 2H NMR (30.7 MHz) studies using ethylbenzene-l,1-d 2 , 3 -fluoroethylbenzene-l,1-d 2 , 4 -fluoroethylbenzene-l,1-d 2 , and toluene-dB as substrates with Mortierella isabellina suggest, based on the observable differences in rates of conversion …
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Nuclear magnetic resonance and rheo-NMR investigations of wormlike micelles, rheology modifiers, and ion-conducting polymers
… we have performed nuclear magnetic resonance (NMR) studies on a variety of chemical systems. In addition to versatile "traditional" NMR measurements, we took advantage of specialized techniques, such as "rheo-NMR," 2H NMR, and NMR self-diffusion experiments to analyze alignment, orientational …
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Molecular self assembly in flurocarbon surfactant / water systems
… using optical polarising microscopy, 2H NMR spectroscopy and small angle x-ray scattering. As n decreases, the phase diagrams change, recovering the "generic" phase behaviour more usual for a perfluorocarbon surfactant - water system. X-ray measurements show that in the n = 4 …
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Electrochemical and NMR Studies of Fuel Cell Catalysts and Carbon Monoxide Surface Diffusion
… electrochemical nuclear magnetic resonance (EC-NMR) spectroscopy and a spin labeling pulse sequence. 2H NMR data indicate that the electrolyte remains in a liquid-like state at temperatures where the experiments were performed. For the fully CO covered samples, the exchange between different CO …
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Investigation into the membrane interaction of E.coli Pencillin binding protein 4
… artificial bilayer has been investigated using 2H NMR. This has been compared with the interactions of P5, a PBP5 C-terminal homologue, and melittin, a well documented membrane interactive protein of similar molecular mass. In the NMR experiments it was found that splitting reduced with …
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Characterising Electrolyte Interactions with Carbon Anodes for Sodium Ion Batteries
… diglyme co-intercalated into hard carbon using 2H NMR and simulations, and then use the dynamics of diglyme as an indirect probe for the structure of hard carbon. It was found that the motion of diglyme can be described by simulating a molecular rotation of diglyme with a lognormal distribution …
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Polymer Melts Investigated by Field Cycling NMR Relaxometry: From Simple Liquid to Reptation Dynamics
… Field Cycling Nuclear Magnetic Resonance (FC NMR) relaxometry. The objective is to understand their microscopic dynamics and its dependence on the molecular mass (M) of the polymer chains. With the commercial availability of FC NMR relaxometers, the method gained attraction for studying …
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