Search results for "Simulation"

Multiphoton Absorption of Myoglobin Nitric-Oxide complex: Relaxation by D-NEMD of a Stationary State

2012

ABSTRACT: The photodissociation and geminate recombination of nitric oxide in myoglobin, under continuous illumination, is modeled computationally. The relaxation of the photon energy into the protein matrix is also considered in a single simulation scheme that mimics a complete experimental setup. The dynamic approach to non-equilibrium molecular dynamics is used, starting from a steady state, to compute its relaxation to equilibrium. Simulations are conducted for the native form of sperm whale myoglobin and for two other mutants, V68W and L29F, illustrating a fair diversity of spatial and temporal geminate recombination processes. Energy flow to the heme and immediate protein environment …

Water effects on trehalose matrices studied through Molecular Dynamics

2012

Computer Simulations of the Band Structure and Density of States of the Linear Chains of NaCl Ions

2019

The authors thank Eugene Kotomin and V. Kuzovkov for fruitful discussions and valuable suggestions. A.I.P thanks A.Moskina for the technical assistance in preparation of the manuscript. A.I.P also gratefully acknowledges a project LZP-2018/1-0214 from the Latvian Council of Science for partial support.

Thermodynamics and kinetics of ion translocation in the human wild-type and E-1_A α7 nicotinic receptor

2021

We use an all-atom model of the human nicotinic acetylcholine receptor α7 in a conductive conformation, to provide the first available mapping of the potential of mean force for the ion translocation across the channel. The modeling is based on MD simulations combined with the milestoning method with Voronoi tessellation. The quality of the protein model and description is confirmed by the agreement with experimental data for proteins of the same family. The specific mutation E-1 ' A at the cytoplasmatic filter is here shown to strongly affect both sodium and chloride permeation, leading to a complete inversion of selectivity.

Novel non-destructive inspection techniques for laser powder deposition inspection

2013

A novel non-destructive testing (NDT) techniques for inspection of parts and components manufactured by Additive Manufacturing Processes (AMP), in particular Laser Metal Deposition (LMD), has been developed. LMD is a technology that has been maturing over the last 20 years and has found application in repair, coatings, hybrid build and 3D near net shape manufacture of small intricate parts that can be used in aero and automobile engines to improve efficiency. Currently this technology cannot be used to supply some of these parts because absence of flaws, which might be left in the component during manufacture, cannot be guaranteed. Today, quality is assessed by sample destructive testing, w…

Non-linear analysis of a modified QPSK Costas loop

2019

A Costas loop is one of the classical phase-locked loop based circuits, which demodulates data and recovers carrier from the input signal. The Costas loop is essentially a nonlinear control system and its nonlinear analysis is a challenging task. In this article for a modified QPSK Costas loop we analyze the hold-in, pull-in and lock-in ranges. New procedure for estimation of the lock-in range is considered and compared with previously known approach. peerReviewed

CALIBRATION OF LÉVY PROCESSES USING OPTIMAL CONTROL OF KOLMOGOROV EQUATIONS WITH PERIODIC BOUNDARY CONDITIONS

2018

We present an optimal control approach to the problem of model calibration for L\'evy processes based on a non parametric estimation procedure. The calibration problem is of considerable interest in mathematical finance and beyond. Calibration of L\'evy processes is particularly challenging as the jump distribution is given by an arbitrary L\'evy measure, which form a infinite dimensional space. In this work, we follow an approach which is related to the maximum likelihood theory of sieves. The sampling of the L\'evy process is modelled as independent observations of the stochastic process at some terminal time $T$. We use a generic spline discretization of the L\'evy jump measure and selec…

Developments in numerical modelling of cardiovascular fluid dynamics

1998

Numerical simulations of wind-loaded floating solar panels

2021

On a nonlinear Schrödinger equation for nucleons in one space dimension

2021

We study a 1D nonlinear Schrödinger equation appearing in the description of a particle inside an atomic nucleus. For various nonlinearities, the ground states are discussed and given in explicit form. Their stability is studied numerically via the time evolution of perturbed ground states. In the time evolution of general localized initial data, they are shown to appear in the long time behaviour of certain cases.