Search results for "Transports"

Memorands jaunbūvējamās dzelzceļu līnijas Rīga-Ērgļi-Kārsava posma Ērgļi-Madona lietā

1934

Mašīnraksta kopija

1,4-Dihidropiridīnu atvasinājumu nanodaļiņu toksiskuma novērtējums mikroorganismos

2017

1,4 Dihidropiridīnu (1,4 DHP) atvasinājumi ir plaša organisko vielu grupa, kurā arvien tiek sintezēti jauni savienojumi ar plašām pielietojuma iespējām. Jauno savienojumu toksicitātes raksturojums ir nepieciešams, lai paredzētu to pielietojuma iespējas un novērtētu to iedarbību uz vidi un dzīvajiem organismiem. Darbā pielāgota universāla un efektīva atšķaidījumu metode, lai noteiktu deviņu katjono amfifilo 1,4 DHP atvasinājumu toksicitātes robežkoncentrācijas sešām baktērijām un vienam raugam. Papildus noteikta 1,4 DHP atvasinājumu ietekme uz iekššūnas ATP daudzumu, skābekļa patēriņa ātrumu un etīdija bromīda transportu šūnās. Noskaidrojot toksicitātes robežkoncentrācijas un gūstot ieskatu …

Complex power distribution analysis in plates covered with passive constrained layer damping patches

2012

International audience; The vibration of a plate partially covered with a passive constrained layer damping (PCLD) patch is studied from an energetic point of view. The damped plate is excited by an acoustic plane wave. The study is done with a numerical two-dimensional multilayer plate model. Results of the present model are compared to those obtained with three-dimensional finite element models. It is shown that the present model gives accurate results, even for the layer's inner behavior. It is less expansive in terms of computational cost; hence, it can simulate efficiently the structure for higher frequencies. Mathematical formulas for complex mechanical power are presented, and the li…

Modéliser la ville

2011

Ouvrage publié avec le soutien de la Direction de la recherche et de l'innovation (service de la recherche) du Commissariat général au développement durable (ministère de l'Écologie, de l'Énergie, du Développement durable et de la Mer), en liaison avec le Programme de recherche et d'innovation dans les transports terrestres - PREDIT 4; National audience; Pour de nombreux acteurs, impliqués professionnellement ou politiquement dans les problématiques de la ville et de son aménagement, il est devenu clair que la planification de l’urbanisation ne peut être déconnectée des politiques de transport : elles interagissent l’une sur l’autre et doivent être considérées ensemble, ce qui nécessite de …

A class of shear deformable isotropic elastic plates with parametrically variable warping shapes

2017

A homogeneous shear deformable isotropic elastic plate model is addressed in which the normal transverse fibers are allowed to rotate and to warp in a physically consistent manner specified by a fixed value of a real non-negative warping parameter ω. On letting ω vary continuously (at fixed load and boundary conditions), a continuous family of shear deformable plates Pω is generated, which spans from the Kirchhoff plate at the lower limit ω=0, to the Mindlin plate at the upper limit ω=∞; for ω=2, Pω identifies with the third-order Reddy plate. The boundary-value problem for the generic plate Pω is addressed in the case of quasi-static loads, for which a principle of minimum total potential …

Arbitrarily shaped plates analysis via Line Element-Less Method (LEM)

2018

Abstract An innovative procedure is introduced for the analysis of arbitrarily shaped thin plates with various boundary conditions and under generic transverse loading conditions. Framed into Line Element-less Method, a truly meshfree method, this novel approach yields the solution in terms of the deflection function in a straightforward manner, without resorting to any discretization, neither in the domain nor on the boundary. Specifically, expressing the deflection function through a series expansion in terms of harmonic polynomials, it is shown that the proposed method requires only the evaluation of line integrals along the boundary parametric equation. Further, minimization of appropri…

Evolutionary Algorithms and Metaheuristics : Applications in Engineering Design and Optimization

2018

Improving accuracy of FIR filters for computing convolution transforms for smooth non-bandlimited signals

2019

We propose to improve the accuracy of FIR filters for computing convolution transforms for smooth non-bandlimited (NBL) signals by designing filters by the identification method with using a pair of bandlimited portions of the chosen NBL input and output signals related with each other by the given transform. A design example of type IV linear phase differentiator is presented, where filter coefficients are calculated from the bandlimited portions of the Cauchy pulse and its derivative. The performance of the designed differentiator is evaluated by comparing the accuracy of computed derivatives for several smooth NBL test signals, such as the Cauchy pulse, the Hilbert transform of Cauchy pu…

Numerical modelling of the tensile behaviour of BFRCM strips

2019

This paper aims at investigating the tensile behaviour of basalt fibres on cementitious matrix for the strengthening of masonry structures. The use of Basalt Fibre Reinforced Cementitious Matrix (BFRCM) is favourably considered by the scientific community because it represents a natural composite material with high compatibility with stone and masonry substrate. The study is developed through the generation of Finite Element (FE) models capable of reproducing the tensile behaviour of BFRCM strips with different number of layers of grid. For the scope, the micro-modelling approach is adopted assuming different levels of detail for the simulation of the interface constitutive behaviour. Fibre…

A bending theory of thermoelastic diffusion plates based on Green-Naghdi theory

2017

Abstract This article is concerned with bending plate theory for thermoelastic diffusion materials under Green-Naghdi theory. First, we present the basic equations which characterize the bending of thin thermoelastic diffusion plates for type II and III models. The theory allows for the effect of transverse shear deformation without any shear correction factor, and permits the propagation of waves at a finite speed without energy dissipation for type II model and with energy dissipation for type III model. By the semigroup theory of linear operators, we prove the well-posedness of the both models and the asymptotic behavior of the solutions of type III model. For unbounded plate of type III…