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Mostrando ítems 41-50 de 52
Artículo
Spiral waves solutions in reaction-diffusion equations with symmetries. Analysis through specific models
(IOP Science, 1997)
Symmetries of nonlinear reaction-diffusion equations determine the existence of regular rotating spiral waves. They are only a consequence of kinetics processes and molecular diffusion. We prove the existence of these waves ...
Artículo
Electrooptical measurement system for the DC characterization of visible detectors for CMOS-compatible vision chips
(IEEE, 1998)
Abstract—An electrooptical measurement system for the dc characterization of visible detectors for CMOS-compatible vision chips is presented, which can help designers to characterize these detectors. The measurement ...
Artículo
Modelling the dispersion of non-conservative radionuclides in tidal waters—Part 1: Conceptual and mathematical model
(Elsevier, 1996)
A 2D four-phase model to study the dispersion of non-conservative radionuclides in tidal waters, in conditions of disequilibrium for ionic exchanges, has been developed. At disequilibrium conditions, ionic exchanges cannot ...
Artículo
Transfer of natural radionuclides from soils to plants in a wet marshland
(Elsevier, 1996)
Soils and two wild plant species (Spartina densiflora and Spartina maritima) have been collected from the Odiel river marsh and analysed for 210Po and 238U. The radioactivity concentrations in plants and soils reflect the ...
Artículo
On the validity of linear hydrodynamics for low-density granular flows described by the Boltzmann equation
(European Physical Society, 1999)
The direct Monte Carlo simulation method is used to check the validity of the hydrodynamic description of a low-density granular flow in the linear region about the homogeneous cooling state. Good agreement is found between ...
Artículo
High energy tail in the velocity distribution of a granular gas
(American Physical Society, 1999)
The Enskog-Boltzmann equation for a homogeneous freely evolving system of smooth hard disks colliding inelastically is solved by means of the direct simulation Monte Carlo method. The distribution function shows an exponential ...
Artículo
U and Th distribution in solution and suspended matter from rivers affected by the phosphate rock processing in southwestern Spain
(Elsevier, 1994)
A study is presented on the distribution of U and Th isotopes in the solid and liquid fractions of waters collected along the Odiel and Tinto rivers (southwest Spain). Such rivers are affected by the operation of phosphate ...
Artículo
Evidencias morfogenéticas cuaternarias en el Karst de la Sierra del Endrinal (Grazalema, Cádiz)
(Sociedad Geológica de España, 1998)
The geomorphological observations made until now reveal a long morphogenic history for the karst of the Eridrinal: mountains; going back to pre-Quaternary times. The erosion surfaces mapped (Sl, S2 and 53) have å biostatic ...
Artículo
A six-phase model to simulate the contamination by non-conservative radionuclides of sediments, soils and plants in a marsh area. Application to the Odiel marsh in southwest Spain
(Elsevier, 1997)
A numerical model to simulate the dispersion of non-conservative radionuclides in an estuarine system that surrounds a marsh area has been developed. The model includes six phases: water, two types of suspended particles ...
Artículo
The use of 137-cs in marine and lacustrine sediment dating
(Pergamon Press, 1992)
En este trabajo, la técnica de datación 137 Cs con precisión mejorada se muestra como una herramienta poderosa para establecer cronologías en diferentes depósitos acuáticos jóvenes (lacustres, marinos). El método tiene ...