Search results for "Structural engineering"
showing 10 items of 1998 documents
Removal of bis(2-ethylhexyl) phthalate at a sewage treatment plant
2003
Bis(2-ethylhexyl) phthalate (DEHP) concentrations were measured at different stages in a full-scale sewage treatment plant (STP) and mass balances were calculated. The DEHP load to treatment process coming from the sewer system and the internal load comprising returned supernatants and filtrate from sludge treatment and excess secondary sludge were at the same level. The DEHP removal efficiency from the water phase at the STP was on average 94% of sewage DEHP, the main removal process being sorption to primary and secondary sludges. On average 29% of DEHP was calculated to be removed in the biological nitrifying-denitrifying activated sludge process, which was much less than expected from l…
The Measurement of Large Strains Using Electrical Resistance Strain Gages
2011
It is well known that in the range of large strains, the electrical resistance strain gages have a nonlinear behavior, that is the variation of electrical resistance is a nonlinear function of the strain applied to the strain gage, which means that the gage factor K is not constant. Also, the Wheatstone bridge has a nonlinear behavior at large strains. Usually the two nonlinearities have opposite effects, therefore the overall nonlinearity decreases. This article presents an overview of the behavior of strain gages subject to large strains and of the corrections to account for nonlinearities of both the strain gage and the Wheatstone bridge.
A New Solution for Sea Wave Energy Harvesting, the Proposal of an Ironless Linear Generator
2020
The paper investigates an innovative ironless linear generator, installable inside a wave energy converter, in order to produce electricity from sea waves. This energy source is considered strategic for the future, especially in small islands
Topological surface wave metamaterials for robust vibration attenuation and energy harvesting
2021
International audience; We propose topological metamaterials working in Hertz frequency range, constituted of concrete pillars on the soil ground in a honeycomb lattice. Based on the analog of the quantum valley Hall effect, a non-trivial bandgap is formed by breaking the inversion symmetry of the unit cell. A topological interface is created between two different crystal phases whose robustness against various defects and disorders is quantitatively analyzed. Finally, we take advantage of the robust and compact topological edge state for designing a harvesting energy device. The results demonstrate the functionality of the proposed structure for both robust surface vibration reduction and …
User behavior in Smart and Sustainable Offices (SSO)
2017
Smart and Sustainable Offices (SSO) require synergies between technologies and users behaviors. The sociotechnical approach considers users’ motives, attitudes, cognitions and behaviors when designing work environments. This note will describe those phenomena in office environments. It will also present a set of tools to assess those phenomena and will provide guidelines to improve them.
An implicit mesh discontinuous Galerkin formulation for higher-order plate theories
2019
In this work, a discontinuous Galerkin formulation for higher-order plate theories is presented. The starting point of the formulation is the strong form of the governing equations, which are derived in the context of the Generalized Unified Formulation and the Equivalent Single Layer approach from the Principle of Virtual Displacements. To express the problem within the discontinuous Galerkin framework, an auxiliary flux variable is introduced and the governing equations are rewritten as a system of first-order partial differential equations, which are weakly stated over each mesh element. The link among neighboring mesh elements is then retrieved by introducing suitably defined numerical …
MAJOR AND TRACE ELEMENTS GEOCHEMISTRY IN THE GROUND WATERS OF A VOLCANIC AREA: MOUNT ETNA (SICILY, ITALY)
1998
Thirty-five ground-water samples have been collected from wells, springs and drainage galleries on Mt Etna volcano for the determination of major, minor and trace elements in solution. Attention has been focused in particular on dissolved minor and trace elements, for most of which no data were available in the studied area. In general, dissolution of solids into Etna's ground waters follows from strong interaction between water of meteoric origin, CO2 gas of magmatic origin and the volcanic rocks of the aquifers. However, the R-mode analysis allowed to distinguish several sources of solutes: Al, Co, Ni, Fe, Si, As would derive mainly from alteration of the volcanic rocks of Etna; SO4=, K, …
Toward the Development of Load Transfer Efficiency Evaluation of Rigid Pavements by a Rolling Wheel Deflectometer
2020
The jointed rigid pavement is currently evaluated by the Falling weight deflectometer which is rather slow for the testing of the jointed pavements. Continuous nondestructive evaluation of rigid pavements with a rolling wheel deflectometer can be used to measure the load transfer and is investigated. Load transfer is an important indicator of the rigid pavement&rsquo
Free vibrations analysis of cracked variable stiffness composite plates by the eXtended Ritz method
2022
Variable stiffness composite laminates show advantageous structural features related to their enlarged design space. They are attractive candidates for advanced engineering applications where the assessment of static and dynamic behavior and strength in the presence of cracks is often required. In the present work, a single-domain extended Ritz formulation is proposed to study the free vibrations of cracked variable stiffness composite plates. The plate model is based on the first-order shear deformation theory whose primary variable, i.e. displacements and rotations, are approximated via a set of orthogonal polynomial trial functions enriched with a set of special crack functions. These fu…
A Logic Fuzzy Model for Evaluation of the Railway Station’s Practice Capacity in Safety Operating Conditions
2013
Abstract The practice capacity of a railway junction depends, in addition to the effective operation’s conditions, by the potential risk factors related to the design plan of the railway station. With the aim of an approach based on the “fuzzy sets” it is possible to determine the numeric value of the practice capacity by the logic - qualitative relations between the features of the railway junction and the potential risk factors. This methodology permits to try out the absolute value of a suitable vector β, (less then the unit) for the utilization of the theoretic capacity in conditions of maximum reliability of the system related to the aspect of safety (technique “fail safe”).