caa a22 4500 463162757 CHVBK 20180406164752.0 cr unu---uuuuu 170326e20070801xx s 000 0 eng 10.1007/s11242-006-9062-7 doi (NATIONALLICENCE)springer-10.1007/s11242-006-9062-7 NMR for equilateral triangular geometry under conditions of surface relaxivity—analytical and random walk solution [Elektronische Daten] [Jan Finjord, Aksel Hiorth, Unn Lad, Svein Skjæveland] We consider analytical and numerical solution of NMR relaxation under the condition of surface relaxation in an equilateral triangular geometry. We present an analytical expression for the Green's function in this geometry. We calculate the transverse magnetic relaxation without magnetic gradients present, single-phase, both analytically and numerically. There is a very good match between the analytical and numerical results. We also show that the magnetic signal from an equilateral triangular geometry is qualitatively different from the known solution: plate, cylinder, and sphere, in the case of a nonuniform initial magnetization. Nonuniform magnetization close to the sharp corners makes the magnetic signal very fast multiexponential. This type of initial configuration fits qualitatively with the experimental results by Song (Phys. Rev. Lett. 85, 3878 (2000)), Song etal. (Nature 406, 178 (2000)), Song (Mag. Reson. Imag. 19, 417 (2001)) and Lisitza and Song (Phys. Rev. B 65, 172406 (2002)). It should also be noted that the solution presented here can be used to describe absorption of a chemical substance in an equilateral triangular geometry (for a stationary fluid). Springer Science+Business Media, Inc., 2006 CPMG NMR nationallicence Diffusion nationallicence Equilateral triangle nationallicence Random walk nationallicence Analytical nationallicence Finjord Jan University of Stavanger, N-4036, Stavanger, Norway aut Hiorth Aksel RF-Rogaland Research, P. O. Box 8046, N-4068, Stavanger, Norway aut Lad Unn RF-Rogaland Research, P. O. Box 8046, N-4068, Stavanger, Norway aut Skjæveland Svein University of Stavanger, N-4036, Stavanger, Norway aut Transport in Porous Media Kluwer Academic Publishers 69/1(2007-08-01), 33-53 0169-3913 69:1<33 2007 69 11242 https://doi.org/10.1007/s11242-006-9062-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11242-006-9062-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Finjord Jan University of Stavanger, N-4036, Stavanger, Norway aut NATIONALLICENCE 700 1- Hiorth Aksel RF-Rogaland Research, P. O. Box 8046, N-4068, Stavanger, Norway aut NATIONALLICENCE 700 1- Lad Unn RF-Rogaland Research, P. O. Box 8046, N-4068, Stavanger, Norway aut NATIONALLICENCE 700 1- Skjæveland Svein University of Stavanger, N-4036, Stavanger, Norway aut NATIONALLICENCE 773 0- Transport in Porous Media Kluwer Academic Publishers 69/1(2007-08-01), 33-53 0169-3913 69:1<33 2007 69 11242 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer