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Showing 1 to 17 of 17 for “"deuterium nmr"”.
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Deuterium NMR relaxation studies of liquids in confined geometries
Nuclear magnetic resonance (NMR) has been employed to study the confined geometry effects on reorientational dynamics of molecular liquids in porous media. The relative role of the pure geometrical confinement and the strength of the surface effect is investigated. The deuteron NMR spin-lattice …
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A biaxial nematic phase in a thermotropic liquid crystalline side-chain polymer : a deuterium NMR study
… crystalline side-chain polymers by means of deuterium NMR spectrodcopy. The lateral attachment of a book-shaped mesogen should - in the case of the system investigated in the beginning - prevent the rotation about the long molecular axis and therefore support the formation of a biaxial …
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Deuteronen-Kernresonanz-Untersuchungen an flüssigkristallinen Polymeren : Kollektive Bewegungen, Direktordynamik und viskoelastische Eigenschaften
… Haupt-Seitenketten-Polymeren werden Deuterium-Kernresonanz (NMR)-Untersuchungen zur molekularen Dynamik durchgeführt. Besonderes Interesse gilt dabei der Dynamik in der nematischen Phase dieser flüssigkristallinen Systeme. Die Analyse von Carr-Purcell-Meiboom-Gill (CPMG)-Experimenten …
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Deuterium Solid State NMR Studies of Pyridine Intercalation Compounds
A quadrupole echo deuterium NMR lineshape study on polycrystalline samples of perdeuterated pyridine and selectively deuterated d$\sb2$-pyridine intercalated into 2H-TaS$\sb2$ was performed between 280K and 393K. The powder pattern lineshapes above 333K show signs of motional narrowing. A short …
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Synthesis, properties, and modifications of engineering polymers
… in order to investigate molecular motion via deuterium NMR. The mechanical, dynamic mechanical and fracture properties of these materials were also examined. Polysulfones were characterized to be tough, ductile materials and it was found that polysulfone-poly(dimethylsiloxane) block copolymers …
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Dynamic nuclear polarization of amorphous and crystalline small molecules
Solid-state NMR has emerged to become an important technique in the studies of pharmaceutical formulations consisting of active pharmaceutical ingredients (API) and excipients. Dynamic nuclear polarization (DNP), which improves NMR sensitivity by 2-3 orders of magnitude, can potentially reduce the …
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NMR studies of acetylene absorbed on supported platinum catalysts
"This thesis describes NMR measurements involving carbon-13, deuterons, and protons in acetylene (C2H2) adsorbed at room temperature on supported platinum catalysts. Measurements from 77""K to 158°K of the spin-lattice relaxation behavior of carbon-13 reveal multiple-exponential behavior. …
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Mobility and Stability Characterization of Model Food Systems Using NMR, DSC, and Conidia Germination Techniques
… and a 1:1 sucrose/starch mixture. A suite of NMR and DSC techniques were used to fully characterize water and solid mobility and Tg of the food systems, respectively. All experiments were done in duplicated at 20$\sp\circ$C. Water content and a$\rm\sb{w}$, were unable to predict mold …
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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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Dynamische Wechselwirkungen zwischen festkörperunterstützten kationischen Lipidbilayern und oligo-DNA
… oder wie in der vorliegenden Arbeit NMR, einfacher untersuchen zu können. Darüber hinaus ist die so präparierte Oberfläche, in Kombination mit vorhandener Halbleitertechnik, ein idealer Sensor, um das Verhalten von Biomolekülen in Wechselwirkung mit dem Lipidbilayer zu untersuchen. …
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The use of enzymes, isomerisable lipid analogues and small molecules to modulate the structure and dynamics of lipid bilayer
… and LY-165,135 was analysed using proton and deuterium NMR spectroscopy and differential scanning calorimetry (DSC). The effect of quipazine and LY-165,135 on d62-DPPC was an elongation of the gel-to-fluid lamellar phase transition, lowering of the start of the phase transition, and …
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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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Polymer dynamics in bulk, adsorbed and solution by NMR methods
… of two topics. The first part deals with deuterium nuclear magnetic resonance (²H NMR) study of bulk and adsorbed polymers. Segmental dynamics of poly(methyl acrylate) is examined in bulk and when adsorbed to anopore, alumina and silica as a function of temperature. The second part …
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Biophysical Studies of Cholesterol in Unsaturated Phospholipid Model Membranes
… mol) was compared by solid-state <sup>2</sup>H NMR spectroscopy. Eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids are the two major n-3 PUFAs found in fish oil, while PEPC-d<sub>31</sub> and PDPC-d<sub>31</sub> are phospholipids containing the respective PUFAs at the sn-2 position and a …
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Solid-state NMR spectroscopy applied to model membranes: effects of polyunsaturated fatty acids
… a model membrane was examined by solid state 2H NMR spectroscopy. Solid state 2H NMR spectroscopy extracts details of molecular orientation and anisotropy of molecular reorientation by analysis of the lineshape. This essentially non-invasive technique allows for a direct measurement of dynamics …
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Anomalous diffusion in anisotropic media
… investigated by pulsed field gradient diffusion NMR and complementary deuterium line shape analysis. Restricted diffusion was studied in two lyotropic lamellar systems, the first consisting of crosslinked flat lamellae in anisotropic hydrogels and the second consisting of spherically bent …