(2000) Meshless local Petrov–Galerkin (MLPG) method in combination with finite element and boundary element approaches. Abstract The Meshless Local Petrov-Galerkin (MLPG) method is an effective truly meshless method for solving partial differential equations using Moving Least Squares (MLS) interpolants. It is, however, computationally expensive for some problems. A coupled MLPG/Finite Element ...

Iron-bearing phyllosilicates strongly influence the redox state and mobility of uranium because of their limited hydraulic conductivity, high specific surface area, and redox reactivity. Standard extraction procedures cannot be accurately applied for the determination of clay-Fe(II/III) and U(IV/VI) in clay mineral-U suspensions such that advanced spectroscopic techniques are required. Instead,...

für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namen...

Kropholler and Mislin conjectured that groups acting admissibly on a finite-dimensional G-CW-complex with finite stabilisers admit a finitedimensional model for EFG, the classifying space for proper actions. This conjecture is known to hold for groups with bounded torsion. In this note we consider a large class of groups U containing the above and many known examples with unbounded torsion. We ...

The electronic structure of nitrogen atoms as impurities in an ionic T i0 2 crystal has been investigated by analyzing electric field gradients (EFGs) measured by use of short-lived /3-emitting N implanted following nuclear reactions. Conventional ß-NMR and its modification, suitable for the detection of quadrupole effects in the NMR spectra, were used for the investigation of hyperfine interac...

The boundary value problem z ′′ ρ·g·z − p /γ 1 z′ 2 3/2 − 1/r · 1 z′ 2 ·z′, r ∈ r1, r0 , z′ r1 − tan π/2 − αg , z′ r0 − tanαc, z r0 0, and z r is strictly decreasing on r1, r0 , is considered. Here, 0 < r1 < r0, ρ, g, γ, p, αc, αg are constants having the following properties: ρ, g, γ are strictly positive and 0 < π/2 − αg < αc < π/2. Necessary or sufficient conditions are given in terms of p f...

While the Mössbauer spectrum of a magnetically ordered powder sample can be used to determine the direction of the local hyperfine field (Bhf) in the coordinate system defined by the electric field gradient (efg) tensor, the spectrum of an oriented single-crystal provides a direct measurement of the angle between the absorbed or emitted γ and Bhf, primarily through the observed line intensities...

Ab initio Hartree-Fock molecular orbital calculations were applied to the crystalline imidazole and its derivatives in order to examine systematically the effect of possible N–H·· ·N type hydrogen bonding on the nuclear quadrupole interaction parameters in these materials. The nitrogen quadrupole coupling constant (QCC) and the asymmetry parameter ( ) of the electric field gradient (EFG) were f...

The 35C1 NQR spin-lattice relaxation mechanism in isomorphous N i(H 20 ) 6SnCl6 and M g(H20 ) 6SnCl6 crystals is reported. The spin-lattice relaxation time T1(j in the Ni compound is determined mainly by a paramagnetic relaxation. However, above ca. 400 K T1Q decreased rapidly and a log vs. T 1 curve was almost linear. This steep decrease of T1Q was explained by reorientational motions of the a...