Search results for "SIMULATION"
showing 10 items of 5095 documents
Lipid carbonyl groups terminate the hydrogen bond network of membrane-bound water.
2015
We present a combined experimental sum-frequency generation (SFG) spectroscopy and ab initio molecular dynamics simulations study to clarify the structure and orientation of water at zwitterionic phosphatidylcholine (PC) lipid and amine N-oxide (AO) surfactant monolayers. Simulated O-H stretch SFG spectra of water show good agreement with the experimental data. The SFG response at the PC interface exhibits positive peaks, whereas both negative and positive bands are present for the similar zwitterionic AO interface. The positive peaks at the water/PC interface are attributed to water interacting with the lipid carbonyl groups, which act as efficient hydrogen bond acceptors. This allows the …
Boundary discretization based on the residual energy using the SGBEM
2007
Abstract The paper has as objective the estimation of the error in the structural analysis performed by using the displacement approach of the Symmetric Galerkin Boundary Element Method (SGBEM) and suggests a strategy able to reduce this error through an appropriate change of the boundary discretization. The body, characterized by a domain Ω and a boundary Γ−, is embedded inside a complementary unlimited domain Ω∞⧹Ω bounded by a boundary Γ+. In such new condition it is possible to perform a separate valuation of the strain energies in the two subdomains through the computation of the work, defined generalized, obtained as the product among nodal and weighted quantities on the actual boundar…
Mechanical Bistable Structures for Microrobotics and Mesorobotics from Microfabrication to Additive Manufacturing
2018
International audience; The use of mechanical bistable structures in the design of microrobots and mesorobots has many advantages especially for flexible robotic structures. However, depending on the fabrication technology used, the adequacy of theoretical and experimental mechanical behaviors can vary widely. In this paper, we present the manufacturing results of bistable structures made with two extensively used contemporary technologies: MEMS and FDM additive manufacturing. Key issues of these fabrication technologies are discussed in the context of microrobotics and mesorobotics applications.
A 3D mesoscopic approach for discrete dislocation dynamics
2001
In recent years a noticeable renewed interest in modeling dislocations at the mesoscopic scale has been developed leading to significant advances in the field. This interest has arisen from a desire to link the atomistic and macroscopic length scales. In this context, we have recently developed a 3D-discrete dislocation dynamics model (DDD) based on a nodal discretization of the dislocations. We present here the basis of our DDD model and two examples of studies with single and multiple slip planes.
The Low Energy-Coupling Respiration in Zymomonas mobilis Accelerates Flux in the Entner-Doudoroff Pathway.
2015
Performing oxidative phosphorylation is the primary role of respiratory chain both in bacteria and eukaryotes. Yet, the branched respiratory chains of prokaryotes contain alternative, low energy-coupling electron pathways, which serve for functions other than oxidative ATP generation (like those of respiratory protection, adaptation to low-oxygen media, redox balancing, etc.), some of which are still poorly understood. We here demonstrate that withdrawal of reducing equivalents by the energetically uncoupled respiratory chain of the bacterium Zymomonas mobilis accelerates its fermentative catabolism, increasing the glucose consumption rate. This is in contrast to what has been observed in o…
Metafore che risuonano.Linguaggio e corpo tra filosofia e neuroscienze
2013
Obiettivo di questo lavoro è quello di individuare un meccanismo di comprensione delle metafore che possa rendere conto di quella sintonizzazione affettivo/ emotiva tra scrittore e lettore che spesso accompagna la lettura. Per definire questa esperienza, che chiameremo esperienza di “risonanza”, la dimensione sensoriale e quella del piacere possono essere essenziali. Il lavoro sarà condotto facendo ampio uso delle evidenze delle neuroscienze cognitive.
Analysis of metal spinning processes by the ADINA code
1989
Abstract The ADINA code, version 84, has been employed for the analysis of sheet spinning processes. The main process parameters have been evaluated in different working conditions; namely for various geometries and constitutive laws of the material.
Data fusion analysis applied to different climate change models: An application to the energy consumptions of a building office
2019
Abstract The paper aims to achieve the modelling of climate change effects on heating and cooling in the building sector, through the use of the available Intergovernmental Panel on Climate Change forecasted data. Data from several different climate models will be fused with regards to mean air temperature, wind speed and horizontal solar radiation. Several climatic models data were analysed ranging from January 2006 to December 2100. Rather than considering each model in isolation, we propose a data fusion approach for providing a robust combined model for morphing an existing weather data file. The final aim is simulating future energy use for heating and cooling of a reference building a…
Large-Eddy Simulation of Turbulent Flow and Heat Transfer in Plane and Rib-Roughened Channels
1992
Large-eddy simulation results are presented and discussed for turbulent flow and heat transfer in a plane channel with and without transverse square ribs on one of the walls. They were obtained with the finite-difference code Harwell-FLOW3D, Release 2, by using the PISOC pressure-velocity coupling algorithm, central differencing in space, and Crank-Nicolson time stepping. A simple Smagorinsky model, with van Driest damping near the walls, was implemented to model subgrid scale effects. Periodic boundary conditions were imposed in the streamwise and spanwise directions. The Reynolds number based on hydraulic diameter (twice the channel height) ranged from 10 000 to 40 000. Results are compar…
Irradiance in polluted cumulus fields: Measured and modeled cloud-aerosol effects
2009
[1] We present a new strategy to validate modeled spectral irradiance of shallow cumulus cloud fields in a polluted background with airborne measurements. The concept is based on a spectral distinction of effects associated with heterogeneous clouds, aerosol particles, and surface albedo. We use measurements from the Gulf of Mexico Atmospheric Composition and Climate Study, conducted in the urban-industrial Houston area. Modeled irradiance fields were obtained from extensive three-dimensional radiative transfer calculations applied to the output of large eddy simulations. We show that the measurements below clouds or cloud gaps can only be reproduced by the calculations when including the a…