Search results for "Placement."
showing 10 items of 1123 documents
Approximate Solution on Large Deflection of Glass Panels Subjected to Uniform Pressure
2015
The estimation of the deflection of glass panels under wind pressure is important in designing external facades of buildings. A direct method to compute the large deflections of glass panels under uniform loads such as wind pressure is presented. The model allows for derivation of the load-deflection response of square or rectangular multilayered glass panels subject to uniform loads. The boundary conditions examined are those of four-point discontinuous supports or continuous supports along the four sides. With some assumptions on bending and membrane action of flat glasses, simple analytical expressions were derived from the elastic theory. Viscoelastic effects for multilayered glass pane…
Focusing of surface-acoustic-wave fields on (100) GaAs surfaces
2003
Focused surface-acoustic waves (SAWs) provide a way to reach intense acoustic fields for electro- and optoacoustic applications on semiconductors. We have investigated the focusing of SAWs by interdigital transducers (IDTs) deposited on (100)-oriented GaAs substrates. The focusing IDTs have curved fingers designed to account for the acoustic anisotropy of the substrate. Different factors that affect focusing, such as the aperture angle and the configuration of the IDT fingers, were systematically addressed. We show that the focusing performance can be considerably improved by appropriate choice of the IDT metal pads, which, under appropriate conditions, create an acoustic waveguide within t…
Experiences with applications of macromolecular tools in supramolecular crystallography
2014
Supramolecular structures, with ever increasing size ranging from a few up to tens of nanometres, represent an intermediate stage between small molecules and biological macromolecules. Many crystal structures of these large supramolecular assemblies have been solved using dual space algorithms. However, supramolecular assemblies with a capsular shape present a particular challenge for crystallography, especially when they are chiral and composed of only light atoms. In this paper, we show that the application of “routine” macromolecular tools may be of great help in solving the crystal structures of supramolecular assemblies that are otherwise refractory to the routine methods of small mole…
Incremental heuristic approach for meter placement in radial distribution systems
2019
The evolution of modern power distribution systems into smart grids requires the development of dedicated state estimation (SE) algorithms for real-time identification of the overall system state variables. This paper proposes a strategy to evaluate the minimum number and best position of power injection meters in radial distribution systems for SE purposes. Measurement points are identified with the aim of reducing uncertainty in branch power flow estimations. An incremental heuristic meter placement (IHMP) approach is proposed to select the locations and total number of power measurements. The meter placement procedure was implemented for a backward/forward load flow algorithm proposed by…
Optimal Placement of Pressure Sensors Using Fuzzy DEMATEL-Based Sensor Influence
2020
[EN] Nowadays, optimal sensor placement (OSP) for leakage detection in water distribution networks is a lively field of research, and a challenge for water utilities in terms of network control, management, and maintenance. How many sensors to install and where to install them are crucial decisions to make for those utilities to reach a trade-off between efficiency and economy. In this paper, we address the where-to-install-them part of the OSP through the following elements: nodes' sensitivity to leakage, uncertainty of information, and redundancy through conditional entropy maximisation. We evaluate relationships among candidate sensors in a network to get a picture of the mutual influenc…
Accidental displacement and migration of endosseous implants into adjacent craniofacial structures: A review and update
2011
Objectives: Accidental displacement of endosseous implants into the maxillary sinus is an unusual but potential complication in implantology procedures due to the special features of the posterior aspect of the maxillary bone; there is also a possibility of migration throughout the upper paranasal sinuses and adjacent structures. The aim of this paper is to review the published literature about accidental displacement and migration of dental implants into the maxillary sinus and other adjacent structures. Study Design: A review has been done based on a search in the main on-line medical databases looking for papers about migration of dental implants published in major oral surgery, periodon…
Computer Simulations of the Dynamics of Amorphous Silica
1999
We present the results of a large scale computer simulation we performed to investigate the dynamical properties of supercooled silica. We show that parallel supercomputers such as the CRAY-T3E are very well suited to solve these type of problems. We find that at low temperatures the transport properties such as the diffusion constants and the viscosity agree well with the experimental data. At high temperatures this simulation predicts that in the transport quantities significant deviations from the Arrhenius law should be observed. Finally we show that such types of simulations can be used to investigate also complex dynamical quantities, such as the dynamical structure factor, and that t…
Equilibrating Glassy Systems with Parallel Tempering
2001
We discuss the efficiency of the so-called parallel tempering method to equilibrate glassy systems also at low temperatures. The main focus is on two structural glass models, SiO2 and a Lennard-Jones system, but we also investigate a fully connected 10 state Potts-glass. By calculating the mean squared displacement of a tagged particle and the spin-autocorrelation function, we find that for these three glass-formers the parallel tempering method is indeed able to generate, at low temperatures, new independent configurations at a rate which is O(100) times faster than more traditional algorithms, such as molecular dynamics and single spin flip Monte Carlo dynamics. In addition we find that t…
Gas transport through polymer membranes and free volume percolation
1998
We consider the influence of structural and dynamical properties of a polymer membrane on the gas transport through this matrix. The diffusant and the polymer only interact through repulsive interactions. In the case of a glassy polymer, when one can consider the matrix as frozen, the gas particle diffusion is determined by the free volume structure of the system. We show how the percolation properties of the free volume show up in a subdiffusive behavior of the diffusant. When one takes matrix mobility into account the ideal percolation transition vanishes but its trace can still be found in a subdiffusive regime in the gas particle mean square displacement. In the statically non-percolati…
Lagrangian finite element modelling of dam–fluid interaction: Accurate absorbing boundary conditions
2007
The dynamic dam-fluid interaction is considered via a Lagrangian approach, based on a fluid finite element (FE) model under the assumption of small displacement and inviscid fluid. The fluid domain is discretized by enhanced displacement-based finite elements, which can be considered an evolution of those derived from the pioneering works of Bathe and Hahn [Bathe KJ, Hahn WF. On transient analysis of fluid-structure system. Comp Struct 1979;10:383-93] and of Wilson and Khalvati [Wilson EL, Khalvati M. Finite element for the dynamic analysis of fluid-solid system. Int J Numer Methods Eng 1983;19:1657-68]. The irrotational condition for inviscid fluids is imposed by the penalty method and con…