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20 results on '"Lumma, D."'

2. Self-diffusion of rodlike and spherical particles in a matrix of charged colloidal spheres: A comparison between fluorescence recovery after photobleaching and fluorescence correlation spectroscopy.

Author

Lellig, C., Wagner, J., Hempelmann, R., Keller, S., Lumma, D., and Härtl, W.

Subjects
PARTICLES, FLUORESCENCE, BLEACHING (Chemistry), TOBACCO mosaic virus, SPECTRUM analysis, LUMINESCENCE
Abstract

The fluorescence recovery after photobleaching (FRAP) method and the fluorescence correlation spectroscopy (FCS) have been applied on suspensions of highly charged colloidal spheres with a small content of rod-shaped tobacco mosaic virus (TMV) particles. Since these methods only determine the self-diffusion coefficient of the fluorescently labeled species, DS of the rods and the spheres could independently be measured. The ionic strength of the dispersion medium has been varied to measure self-diffusion of rods and spheres in dependence on the degree of order of the matrix spheres. In contrast to FRAP, which allows the determination of the long-time self-diffusion coefficient DSL, FCS measures self-diffusion on a shorter time scale. Thus a comparison of the results that were obtained by FCS and FRAP, in combination with Brownian Dynamics simulations, gives insight into the time dependence of the self-diffusion coefficient of an interacting colloidal system. As the mean interparticle distance of the matrix is of the same order of magnitude as the length of a TMV rod, the rotational motion is influenced by the assembly of spheres around a TMV particle. Since FCS is sensitive both to translational and rotational motion, whereas FRAP, which probes the diffusion at much larger length scales, is only sensitive to the translational motion of TMV, the comparison of diffusion coefficients measured employing FRAP and FCS can give some insights in the rotational diffusion: the experimental data indicate a slowing down of the rotational motion of a TMV rod with increasing structural order of the matrix spheres. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2004
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5. Surface Dynamics of Polymer Films

Author

Kim, Hyunjung, primary, Rühm, A., additional, Lurio, L. B., additional, Basu, J. K., additional, Lal, J., additional, Lumma, D., additional, Mochrie, S. G. J., additional, and Sinha, S. K., additional

Published
2003
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8. A time-resolved X-ray scattering experiment for the study of phase transitions and crystallization processes in metallic alloys.

Author

Pelletier, J. F., Sutton, M., Altounian, Z., Saini, S., Lurio, L. B., Sandy, A. R., Lumma, D., Borthwick, M. A., Falus, P., Mochrie, S. G. J., and Stephenson, G. B.

Subjects
CRYSTALLIZATION, ALLOYS, X-ray scattering
Abstract

An experimental setup to perform high-resolution time-resolved X-ray scattering has been commissioned on the side station of beamline 8-ID at the Advanced Photon Source. A Peltier-cooled diode detector array covering an angle range of 20 degrees is mounted on a 4-circle goniometer and is used to temporally resolve X-ray scattering patterns with a resolution up to 10 ms. Metallic ribbon samples can be quickly heated and cooled from temperatures up to 500 °C inside a furnace with controllable atmosphere and equipped with a beryllium window. A description of the setup is presented along with actual results showing time-resolved phase transitions and crystallization processes in AlYNi metallic alloys. These results demonstrate the power of this technique to investigate complex crystallization processes as well as the versatility of this time-resolved X-ray scattering spectrometer. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2000

12. Absence of Scaling for the Intermediate Scattering Function of a Hard-Sphere Suspension: Static and Dynamic X-Ray Scattering from Concentrated Polystyrene Latex Spheres

Author

Lurio, L. B., primary, Lumma, D., additional, Sandy, A. R., additional, Borthwick, M. A., additional, Falus, P., additional, Mochrie, S. G. J., additional, Pelletier, J. F., additional, Sutton, M., additional, Regan, Lynne, additional, Malik, A., additional, and Stephenson, G. B., additional

Published
2000
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15. Experimental investigation of transport phenomena in the scrape-off layer and divertor

Author

Labombard, B., primary, Goetz, J.A., additional, Hutchinson, I., additional, Jablonski, D., additional, Kesner, J., additional, Kurz, C., additional, Lipschultz, B., additional, McCracken, G.M., additional, Niemczewski, A., additional, Terry, J., additional, Allen, A., additional, Boivin, R.L., additional, Bombarda, F., additional, Bonoli, P., additional, Christensen, C., additional, Fiore, C., additional, Garnier, D., additional, Golovato, S., additional, Granetz, R., additional, Greenwald, M., additional, Horne, S., additional, Hubbard, A., additional, Irby, J., additional, Lo, D., additional, Lumma, D., additional, Marmar, E., additional, May, M., additional, Mazurenko, A., additional, Nachtrieb, R., additional, Ohkawa, H., additional, O'Shea, P., additional, Porkolab, M., additional, Reardon, J., additional, Rice, J., additional, Rost, J., additional, Schachter, J., additional, Snipes, J., additional, Sorci, J., additional, Stek, P., additional, Takase, Y., additional, Wang, Y., additional, Watterson, R., additional, Weaver, J., additional, Welch, B., additional, and Wolfe, S., additional

Published
1997
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17. Comparison of detached and radiative divertor operation in Alcator C-Mod

Author

Goetz, J. A., primary, Kurz, C., additional, LaBombard, B., additional, Lipschultz, B., additional, Niemczewski, A., additional, McCracken, G. M., additional, Terry, J. L., additional, Boivin, R. L., additional, Bombarda, F., additional, Bonoli, P., additional, Fiore, C., additional, Golovato, S., additional, Granetz, R., additional, Greenwald, M., additional, Horne, S., additional, Hubbard, A., additional, Hutchinson, I., additional, Irby, J., additional, Marmar, E., additional, Porkolab, M., additional, Rice, J., additional, Snipes, J., additional, Takase, Y., additional, Watterson, R., additional, Welch, B., additional, Wolfe, S., additional, Christensen, C., additional, Garnier, D., additional, Jablonski, D., additional, Lo, D., additional, Lumma, D., additional, May, M., additional, Mazurenko, A., additional, Nachtrieb, R., additional, O’Shea, P., additional, Reardon, J., additional, Rost, J., additional, Schachter, J., additional, Sorci, J., additional, Stek, P., additional, Umansky, M., additional, and Wang, Y., additional

Published
1996
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20. Charge and size dependence of liposome diffusion in semidilute biopolymer solutions.

Author

Rusu L, Lumma D, and Rädler JO

Subjects
Diffusion, Models, Biological, Particle Size, Collagen chemistry, DNA chemistry, Gene Transfer Techniques, Liposomes chemistry, Mucins chemistry, Polylysine chemistry
Abstract

The diffusion of liposomes and PL/DNA complexes in mucin and collagen solutions, considered to model 'in vivo' colloidal gene delivery vector transport, is studied with FCS. The diffusion of defined liposomes is investigated as a function of particle size, surface charge, and the deviation from the Stokes-Einstein behavior. In all cases the self-diffusion coefficient decreases exponentially with polymer concentration. The same surface charge dependence of diffusion is observed in mucin for PL/DNA complexes with either positive or negative excess charge. Incubation of positively-charged PL/DNA complexes in a natural lung surfactant lipid increases the diffusion coefficients to almost the same as for the negatively-charged PL/DNA complexes., (Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Published
2010
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