Archivio della ricerca dell'Università di Modena e Reggio Emiliahttps://iris.unimore.itIl sistema di repository digitale IRIS acquisisce, archivia, indicizza, conserva e rende accessibili prodotti digitali della ricerca.Sun, 26 Jan 2020 11:04:33 GMT2020-01-26T11:04:33Z101191A theory of the dielectric loss in the aligned nematic mesophasehttp://hdl.handle.net/11380/738875Titolo: A theory of the dielectric loss in the aligned nematic mesophase
Abstract: A theory of dielectric absorption and dispersion in the nematic phase is developed which does not rely on the use of a nematic “director”. The major features of the spectrum are reproduced by using the fact that the autocorrelation functions 〈μ(0) · υ(t)〉 and 〈υ(t) · μ(0)〉 are no longer symmetry disallowed when the overall sample is anisotropic, as in the aligned nematic. Here μ is the dipole vector of the diffusing molecule and υ the centre of mass linear velocity.
Thu, 01 Jan 1981 00:00:00 GMThttp://hdl.handle.net/11380/7388751981-01-01T00:00:00ZOn the configurational temperature Nosè-Hoover thermostathttp://hdl.handle.net/11380/1137550Titolo: On the configurational temperature Nosè-Hoover thermostat
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/11380/11375502016-01-01T00:00:00ZMolecular dynamics simulations of the Trp repressor-DNA complex and the AV77 mutanthttp://hdl.handle.net/11380/306443Titolo: Molecular dynamics simulations of the Trp repressor-DNA complex and the AV77 mutant
Abstract: Molecular dynamics simulations were performed on E. coli wild type (WT) Trp repressor and the AV77 mutant in interaction with DNA. Alanine to valine mutation at position 77 results in a repressor with enhanced activity at low concentrations of the L-Trp co-repressor. However, WT and AV77 mutant show an identical crystallographic structure, preventing to devise a clear structure-function correlation and suggesting that the different activity could be ascribed to a varied dynamical behavior. Root mean square deviations, dynamical cross correlation and hydrogen bond analysis have been performed to detect specific differences between the two repressor forms, showing that both ligand and DNA binding is different in the two complexes.
Sat, 01 Jan 2005 00:00:00 GMThttp://hdl.handle.net/11380/3064432005-01-01T00:00:00ZRare events by constrained molecular dynamicshttp://hdl.handle.net/11380/305989Titolo: Rare events by constrained molecular dynamics
Abstract: We present a computationally efficient molecular dynamics method, based on holonomic constraints, devised to estimate the rate constants of rare activated events of short duration. We assume that the process is described by a reaction coordinate xi (r), a well-defined function in configuration space, and we constrain the system at the bottleneck region by prescribing the value of xi (r) MD trajectories sample phase space according to a biased configurational distribution and averages can be taken from such a new Blue Moon. ensemble, with suitable reweighting, to study rare events. (C) 2000 Elsevier Science B.V. All rights reserved.
Sat, 01 Jan 2000 00:00:00 GMThttp://hdl.handle.net/11380/3059892000-01-01T00:00:00ZLong-time tails in two-dimensional fluids by molecular dynamicshttp://hdl.handle.net/11380/306306Titolo: Long-time tails in two-dimensional fluids by molecular dynamics
Abstract: We report on molecular dynamics simulation of long-time tails in the velocity and stress autocorrelation functions of a dense two-dimensional fluid. Large systems of the order of hundred thousand particles have been investigated, performing canonical averages over an ensemble of trajectories generated on a parallel computer. We find the well-known t(-1) decay for the velocity autocorrelation function at two different densities of the;fluid, together with a faster than linear time dependence for the mean-square displacement at long times. Although there are indications of an asymptotically faster decay, the data are not precise enough to discriminate whether the decay is in agreement with the (t root 1n t)(-1) prediction of consistent mode-coupling theory or it is due to finite size effects. No evidence, within the statistical errors, is found for a long-time tail in the stress autocorrelation function. This finding is in agreement with recent NEMD results [Hoover et al., Phys. Rev. E 51 (1995) 273; Gravina et al., Phys. Rev. E 52 (1995) 6123], who find an analytical dependence of the shear viscosity upon the shear rate with no evidence for divergence in the Green-Kubo value.
Wed, 01 Jan 1997 00:00:00 GMThttp://hdl.handle.net/11380/3063061997-01-01T00:00:00ZOn the establishment of thermal diffusion in binary Lennard-Jones liquidshttp://hdl.handle.net/11380/1137548Titolo: On the establishment of thermal diffusion in binary Lennard-Jones liquids
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/11380/11375482016-01-01T00:00:00ZNon-equilibrium by molecular dynamics: a dynamical approachhttp://hdl.handle.net/11380/1137552Titolo: Non-equilibrium by molecular dynamics: a dynamical approach
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/11380/11375522016-01-01T00:00:00ZProceedings of the Europhysics Conference on Computational Physics 2004 - CCP 2004 - Genova, Italy - September 1-4, 2004 - Prefacehttp://hdl.handle.net/11380/3487Titolo: Proceedings of the Europhysics Conference on Computational Physics 2004 - CCP 2004 - Genova, Italy - September 1-4, 2004 - Preface
Abstract: Preface to the Conference Proceedings
Sat, 01 Jan 2005 00:00:00 GMThttp://hdl.handle.net/11380/34872005-01-01T00:00:00ZThe non‐Markovian relaxation process as a ‘‘contraction’’ of a multidimensional one of Markovian typehttp://hdl.handle.net/11380/738318Titolo: The non‐Markovian relaxation process as a ‘‘contraction’’ of a multidimensional one of Markovian type
Abstract: A new approach for obtaining the Fokker–Planck equation to be associated with the generalized Langevin equation is discussed. By using the Mori expansion of the ’’memory kernel,’’ it is shown that any information of interest may be provided by a suitable multidimensional Fokker–Planck equation of Markovian type. A suitable ’’contraction’’ process, furthermore, enables us to find the same two‐point conditional probability as the one recently obtained by Fox. This approach may be useful to overcome the Markov approximation which is present in the stochastic Liouville equation theory.
Mon, 01 Jan 1979 00:00:00 GMThttp://hdl.handle.net/11380/7383181979-01-01T00:00:00ZMolecular dynamics of rigid systems in cartesian coordinates A general formulationhttp://hdl.handle.net/11380/739822Titolo: Molecular dynamics of rigid systems in cartesian coordinates A general formulation
Abstract: The dynamics of rigid polyatomic systems, either molecules or rigid portions of large molecules, is described by cartesian equations of motion for its atoms. In comparison with the original version of the method of constraints
Fri, 01 Jan 1982 00:00:00 GMThttp://hdl.handle.net/11380/7398221982-01-01T00:00:00Z