Search results for "value"
showing 10 items of 5321 documents
Modelling excitonic energy transfer in the photosynthetic unit of purple bacteria
2009
Abstract Molecular mechanics and quantum chemical configuration interaction calculations in combination with exciton theory were used to predict vibronic energies and eigenstates of light harvesting antennae and the reaction centre and to evaluate excitation energy transfer rates in the photosynthetic unit of purple bacteria. Excitation energy transfer rates were calculated by using the transition matrix formalism and exciton basis sets of the interacting antenna systems. Energy transfer rates of 600–800 fs from B800 ring to B850 ring in the LH2 antenna, 3–10 ps from LH2 to LH2 antenna, 2–8 ps from LH2 to LH1 antenna and finally 30–70 ps from LH1 to the reaction centre were obtained. Depend…
On the Weak Solution of the Fluid-Structure Interaction Problem for Shear-Dependent Fluids
2016
In this paper the coupled fluid-structure interaction problem for incompressible non-Newtonian shear-dependent fluid flow in two-dimensional time-dependent domain is studied. One part of the domain boundary consists of an elastic wall. Its temporal evolution is governed by the generalized string equation with action of the fluid forces by means of the Neumann type boundary condition. The aim of this work is to present the limiting process for the auxiliary \((\kappa,\varepsilon,k)\)-problem. The weak solution of this auxiliary problem has been studied in our recent work (Hundertmark-Zauskova, Lukacova-Medvid’ova, Necasova, On the existence of weak solution to the coupled fluid-structure in…
Numerical Study of Forced MHD Convection Flow and Temperature Around Periodically Placed Cylinders
2016
In this paper we consider 2D stationary boundary value problems for the system of magnetohydrodynamic (MHD) equations and the heat transfer equation. The viscous electrically conducting incompressible liquid moves between infinite cylinders with square or round sections placed periodically. We also consider similar 2D MHD channel flow with periodically placed obstacles on the channel walls. We analyse the 2D forced and free MHD convection flow and temperature around cylinders and obstacles in homogeneous external magnetic field. The cylinders, obstacles and walls of the channel with constant temperature are heated. The distributions of electromagnetic fields, forces, velocity and temperatur…
Application of Tunable-Slip Boundary Conditions in Particle-Based Simulations
2014
Compared to macroscopic systems, fluids on the micro- and nanoscales have a larger surface-to-volume ratio, thus the boundary condition becomes crucial in determining the fluid properties. No-slip boundary condition has been applied successfully to wide ranges of macroscopic phenomena, but its validity in microscopic scale is questionable. A more realistic description is that the flow exhibits slippage at the surface, which can be characterized by a Navier slip length. We present a tunable-slip method by implementing Navier boundary condition in particle-based computer simulations (Dissipative Particle Dynamics as an example). To demonstrate the validity and versatility of our method, we ha…
The build-up and relaxation of stresses in a glass-forming soft-sphere mixture under shear: A computer simulation study
2009
Molecular-dynamics computer simulations in conjunction with Lees-Edwards boundary conditions are used to investigate a glass-forming binary Yukawa fluid under shear. The transition from the elastic response to plastic flow is elucidated by studying the stress relaxation after switching off the shear. We find a slow stress relaxation starting from states in the elastic regime and a fast one starting from states in the plastic-flow regime. We show that these relaxation patterns are related to a different distribution of local microscopic stresses in both cases.
Numerical modelling of asymmetric boudinage
2002
Abstract Asymmetric boudinage structures are commonly used as shear sense indicators but their development is incompletely understood. This paper describes the influence of initial shape and kinematic parameters on the evolution of boudin trains using a numerical approach based on the finite difference code FLAC. Boudin trains are simulated as a series of competent objects embedded in a soft matrix subjected to general monoclinic ductile flow. Deformation of boudin trains includes heterogeneous stretching, rotation of boudins and offset along the neck regions. The sense of relative boudin offset is mainly influenced by the initial orientation of the interboudin plane in the boudinaging laye…
Influence of exercise loading on magnetic resonance image texture of thigh soft tissues.
2013
Adaptation to exercise training can affect bone marrow adiposity; muscle-fat distribution; and muscle volume, strength and architecture. The objective of this study was to identify exercise-load-associated differences in magnetic resonance image textures of thigh soft tissues between various athlete groups and non-athletes. Ninety female athletes representing five differently loading sport types (high impact, odd impact, high magnitude, repetitive low impact and repetitive non-impact), and 20 non-athletic clinically healthy female controls underwent magnetic resonance imaging. Five thigh muscles, subcutaneous fat and femoral bone marrow were analysed with co-occurrence matrix-based quantita…
PVN priekšnodokļa atskaitīšanas juridiskās īpatnības
2015
Priekšnodokļa atskaitīšanas tiesību pareiza izmantošana mūsdienās ir aktuāla problēma. Bieži šīs tiesības tiek liegtas nepamatoti, ka arī ļaunprātīgi izmantotās, pretlikumīgi samazinot valsts budžetu. Pētījuma mērķis ir izskaidrot, kā ir jāinterpretē tiesību normas, kuras regulē šīs tiesībās, kādos gadījumos rodas tiesības uz Pievienotās vērtības nodokļa priekšnodokļa atskaitīšanu, kā tās var izmantot Eiropas Savienībā. Ka arī raksturot atbildību par nepamatoti atskaitītām priekšnodokļa summām, soda veidus, nodokļu revīzijas lēmumu apstrīdēšanas tiesības. Pētījuma rezultātā autors izvirzīja dažus priekšlikumus, kā atrisināt šo problēmu, papildinot Administratīvo procesa likumu un citus sais…
Estimating intrinsic image from successive images by solving underdetermined and overdetermined systems of the dichromatic model
2020
International audience; Estimating an intrinsic image from a sequence of successive images taken from an object at different angles of illumination can be used in various applications such as objects recognition, color classification, and the like; because, in so doing, it can provide more visual information. Meanwhile, according to the well-known dichromatic model, each image can be considered a linear combination of three components, including intrinsic image, shading factor, and specularity. In this study, at first, two simple independent constrained and parallelized quadratic programming steps were used for computing values of the shading factor and the specularity of each successive of…
Selective Change-Driven Image Processing: A Speeding-Up Strategy
2009
Biologically inspired schemes are a source for the improvement of visual systems. Real-time implementation of image processing algorithms is constrained by the large amount of data to be processed. Full image processing is many times unnecessary since there are many pixels that suffer a small change or not suffer any change at all. A strategy based on delivering and processing pixels, instead of processing the complete frame, is presented. The pixels that have suffered higher changes in each frame, ordered by the absolute value of its change, are read-out and processed. Two examples are shown: a morphological motion detection algorithm and the Horn and Schunck optical flow algorithm. Result…