0000000000023256

AUTHOR

Theodore E. Simos

showing 4 related works from this author

Multiscale Particle Method in Solving Partial Differential Equations

2007

A novel approach to meshfree particle methods based on multiresolution analysis is presented. The aim is to obtain numerical solutions for partial differential equations by avoiding the mesh generation and by employing a set of particles arbitrarily placed in problem domain. The elimination of the mesh combined with the properties of dilation and translation of scaling and wavelets functions is particularly suitable for problems governed by hyperbolic partial differential equations with large deformations and high gradients.

Multiresolution analysiMethod of linesMathematical analysisFirst-order partial differential equationExponential integratorSPH methodStochastic partial differential equationSettore ING-IND/31 - ElettrotecnicaSettore MAT/08 - Analisi NumericaMultigrid methodMethod of characteristicsMeshfree particle methodHyperbolic partial differential equationNumerical partial differential equationsMathematicsAIP Conference Proceedings
researchProduct

The Study Of The Nuclear Motion In D2+ Molecular Ion By Using The Harmonic Spectra

2007

In this paper we show how it is possible to investigate the nuclei dynamics of a D2+ molecular ion by using the high harmonic generation spectra emitted by the system when subjected to an intense laser field. In particular, the emitted spectra contains, in addition to the usual odd harmonic peaks, additional satellite peaks whose frequency spacing is equal to the vibrational frequency of the nuclei.

PhysicsSettore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciField (physics)Polyatomic ionLasermolecule-laser interactionSpectral lineSettore FIS/03 - Fisica Della Materialaw.inventionlawMolecular vibrationHarmonicNuclei dynamicHigh harmonic generationEmission spectrumAtomic physics
researchProduct

Ultrafast Electron Transfer in Photosynthesis: Reduced Pheophytin and Quinone Interaction Mediated by Conical Intersections

2007

The mechanism of electron transfer (ET) from reduced pheophytin (Pheo−) to the primary stable photosynthetic acceptor, a quinone (Q) molecule, is addressed by using high‐level ab initio computations and realistic molecular models. The results reveal that the ET process involving the (Pheo−+Q) and (Pheo+Q−) oxidation states can be essentially seen as an ultrafast radiationless transition between the two hypersurfaces taking place via conical intersections (CIs) and it is favoured when the topology of the interacting moieties make possible some overlap between the lowest occupied molecular orbitals (LUMO) of the two systems. Thus, it is anticipated that large scale motions, which are difficul…

Photosynthetic reaction centrePheophytinElectron transferchemistry.chemical_compoundChemistryAb initio quantum chemistry methodsMolecular orbitalPhotochemistryQuantum chemistryAcceptorHOMO/LUMOAIP Conference Proceedings
researchProduct

Monotony Based Imaging in EIT

2010

We consider the problem of determining conductivity anomalies inside a body from voltage‐current measurements on its surface. By combining the monotonicity method of Tamburrino and Rubinacci with the concept of localized potentials, we derive a new imaging method that is capable of reconstructing the exact (outer) shape of the anomalies. We furthermore show that the method can be implemented without solving any non‐homogeneous forward problems and show a first numerical result.

Surface (mathematics)Partial differential equationMathematical analysisMonotonic functionBoundary value problemOperator theoryConductivityElectrical impedance tomographyMathematicsMathematical OperatorsAIP Conference Proceedings
researchProduct