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Characterizing colloidal nanocrystals with NMR looking at the capping ligandFritzinger, Bernd, Moreels, Iwan, Lommens, Petra, Hens, Zeger, Martins, José C. January 2007 (has links)
No description available.
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Surface self diffusion of hydrogen on carbon support by quasielastic neutron scatteringHaas, Ole-Erich, Kjelstrup, Signe, Lund Ramstad, Astrid, Fouquet, Peter, Rols, Stéphane, Mutka, Hannu January 2007 (has links)
No description available.
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SEM analysis application to study CO 2 capture by means of dolomiteGallucci, Katia, Paolini, Ferdinando, Di Felice, Luca, Courson, Claire, Foscolo, Pier Ugo, Kiennemann, Alain January 2007 (has links)
No description available.
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The effectiveness of dolomite and Ni-catalyst mixtures for pure H 2 production by methane steam reforming via CO 2 captureSeitkaliyeva, Nurgul, Jand, Nader, Foscolo, Pier Ugo January 2007 (has links)
High hydrogen yields have been obtained continuously from steam reforming of methane coupled with simultaneous CO2 capture[1], at lower temperature (630oC) and pressure (1 atm) than those typical of traditional processes (800-900oC,15-30 atm), using
calcined dolomite and a pulverized commercial Ni catalyst, in a single step. On the other hand, a pure CO2 stream is obtained by subsequent regeneration of the sorbent, which could be stored. A bubbling fluidized bed contained in a quartz vessel was operated batchwise. First, the durability of a dolomite in multi-cycle CO2 sorption/desorption runs has been investigated: a remarkable reduction of dolomite activity is observed after the first calcination, but substantially stable activity was conserved up to the fifth cycle. Then the performance of sorption enhanced catalytic steam reforming of methane to pure hydrogen has been evaluated. Two well
distinct operation regimes have been found: before dolomite saturation, H2 concentration in the dry product gas remained stable at 94-96%, and CO2 was completely converted into calcium carbonate; after a short breakthrough period, concentration of H2 at the exit of the reactor reduced its value that became approximately equal to the equilibrium value expected for methane reforming and water gas shift reactions.
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Hydrodynamic dispersion of pressure-induced and electroosmotic flow in porous glasses probed by Nuclear Magnetic ResonanceLi, Yujie, Farrherr, German, Kimmich, Rainer January 2007 (has links)
Fluid transport by flow in random porous media is subject to hydrodynamic dispersion. In a series of pulsed field-gradient NMR experiments, we have compared flow induced by pressure gradients on the one hand and by electroosmosis on the other.
The media were porous glasses with pore dimensions from 1 to 100 μm. With increasing flow rates, a crossover from subdiffusive to superdiffusive mean-squared displacement laws was observed in both cases. This demonstrates the competition between molecular diffusion and convection, and is a typical example of anomalous transport.
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Red blood cell shape evolution probed by fast-diffusion Nuclear Magnetic Resonance measurementsPages, Guilhem, Kuchel, Philip W. January 2007 (has links)
No description available.
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Polymer dynamics from synthetic to biological macromoleculesRichter, Dieter, Biehl, Ralf, Monkenbusch, Michael, Hoffmann, Bernd, Merkel, Rudolf January 2007 (has links)
In soft materials entropic and enthalpic contributions are of similar magnitude and balance each other. Therefore, the macroscopic mechanical and rheological properties and the phase changes are determined to a high degree by thermal motion of the atoms
and molecules. Most of the relevant dynamics takes place on mesoscopic length and time scales in between the picosecond atomic scale and the macroscopic frame. Allowing for the proper space time observation window, neutron spin echo (NSE) spectroscopy
uniquely allows to address these motions. Here we briefly present some key experimental results on the mesoscopic dynamics of polymer systems, starting from the standard model of polymer motion - the Rouse model. We briefly touch the role of topological
confinement as expressed in the reptation model and discuss in some more detail processes limiting the confinement. In the second part we touch on some new developments relating to large scale internal dynamics of proteins by neutron spin echo. We will report results of some pioneering studies which show the feasibility of such experiments on large scale protein motion which will most likely initiate further studies.
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Size dependence of solute diffusivity and Stokes-Einstein relationship: effect of van der Waals interactionSharma, Manju, Yashonath, Subramanian January 2007 (has links)
Size dependence of solute diffusivity has been investigated using molecular dynamics simulations for a range of solute radii in a binary mixture consisting of solute and solvent species. We demonstrate that the Stokes-Einstein relationship between self diffusivity
and solute radius breaks down over a range of solute-solvent size ratios. This is a result of the previously known Levitation Effect. Three distinct regimes can be seen depending on the solute-solvent size ratio. Several properties have been computed to understand
the nature of solute motion in the three regimes.
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The glass transition near the free surfaceSikorski, Marcin, Gutt, Christian, Dill, Frank-Uwe, Franz, Hermann January 2007 (has links)
No description available.
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500 |
Electrophoretic NMR (eNMR) – methods and applicationsHallberg, Fredrik, Pettersson, Erik, Dvinskikh, Sergey, Vernersson, Thomas, Lindberg, Göran, Furó, István, Stilbs, Peter January 2007 (has links)
No description available.
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