Search results for "Mechanics of Material"

Stiffness and strength of composite truss beam to R.C. column connection in MRFs

2015

Abstract The results of experimental and numerical investigations on the cyclic behavior of composite truss beam to reinforced concrete column connection of moment resisting frames are reported. The beams are constituted by a steel truss and end zone added rebar embedded within a concrete block cast in place, so that, after curing, the steel truss and the added rebar work together with the concrete matrix as reinforcement of the composite beam. Particularly, three specimens of two-span continuous beams were tested under monotonic and cyclic actions as three point bending test. With the goal to investigate about the behavior of the end zone of the beam integrated into a moment resisting fram…

Performance of Steel Fibrous Reinforced Concrete Corbels Subjected to Vertical and Horizontal Loads

2009

A softened strut-and-tie macromodel able to reproduce the flexural behavior of corbels in plain and fibrous concrete and with the presence of steel bars, including softening of compressed struts and yielding of main and secondary steel bars, is presented in this paper. The main focus of the proposed model is the determination of the load-deflection curves of corbels subjected to the coupled effects of vertical and horizontal forces bearing in mind the influence of the type of concrete (normal or high strength), of the fiber percentage and of the arrangement and percentage of the main and secondary (horizontal stirrup) steel bars. A validation of the proposed model is made therefore with ref…

Acene-type donors bearing one 1,3-dithiole ring

1999

Abstract A series of acene-type donors bearing only one 1,3-dithiole ring have been synthesized by following a Wittig-Horner reaction from 7 H -benz[ d,e ]anthracen-7-one and several phosphonate esters. The excellent donor properties have been studied using both experimental techniques and quantum-chemical calculations and reveal that the extraction of the first electron in the oxidation process occurs from the dithiole ring (0.42 e) and the acene unit (0.58 e).

Experimental observations of upstream overdeepening

2005

The issue of morphodynamic influence in meandering streams is investigated through a series of laboratory experiments on curved and straight flumes. Both qualitative and quantitative observations confirm the suitability of the recent theoretical developments (Zolezzi & Seminara 2001) that indicate the occurrence of two distinct regimes of morphodynamic influence, depending on the value of the width ratio of the channel β. The threshold value βR separating the upstream from the downstream influence regimes coincides with the resonant value discovered by Blondeaux & Seminara (1985). Indeed it is observed that upstream influence may occur only in relatively wide channels, while narrower stream…

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…

Inhibitoren der Korrosion 30 (1,2) - Vergleichende Studien über das Verhalten bekannter und bisher unbekannter Inhibitoren der Korrosion des Kupfers …

1985

Folgende Verbindungen wurden auf ihre Fahigkeit zur Inhibierung der Korrosion von Kupferproben unter Standardbedingungen uberpruft: Benzotriazol (BTA), 5-Aminotetrazol-monohydrat (5-AT), 2,5-Diphenyl-3-(m-chlorphenyl)-tetrazolium-nitrat (Tetrazin-B), α- und β-Naphthylamin, Phenylthioharnstoff, Xanthanwasserstoff, 2-Mercaptothiazolin (2-MT) und Kupferron. Folgende Messungen wurden durchgefuhrt: Bestimmung der Geschwindigkeit der Sauerstoffaufnahme im Schuttelversuch und pH-statische Verfolgung des Korrosionsverlaufs in Abhangigkeit (a) von der Konzentration des Inhibitors, (b) dem Verteilungszustand der Kupferprobe (Korn, Staub, Blech), (c) der Anwesenheit von Cu2+-Ionen und (d) dem pH-Wert.…

Evaluación del efecto rejuvenecedor de bio-materiales sobre ligantes para mezclas con alto contenido de asfalto recuperado

2017

The interest in using bio-materials in pavement engineering has grown significantly over the last decades due to environmental concerns about the use of non-recoverable natural resources. In this paper, bio-materials are used together with Reclaimed Asphalt (RA) to restore some of the properties of the aged bitumen present in mixtures with high RA content. For this purpose, two bio-materials are studied and compared to conventional and polymer modified bitumens. Blends of these materials with RA bitumen were produced and studied to simulate a 50% RA mixture. The rejuvenating effect of the two bio-materials on RA has been assessed and compared with the effect of the conventional binders. App…

Application of the 3-D boundary element method to delaminated composite structures

2013

A three-dimensional boundary element model for anisotropic solids is presented to study the fracture mechanics behavior of delaminated composite structures. The multi-domain technique is implemented to model the layered configurations and the cracks occurring at bi-material interface. The Modified Crack Closure Integral technique is implemented to characterize the fracture mechanics behavior of delaminations in terms of the total energy release rate and mode mix phase angles. Validating analyses, performed on different delaminated configurations, have shown the effectiveness of the proposed approach. Moreover, some original results are presented to investigate the effects of the stacking se…

Hybrid molecular materials formed by alternating layers of bimetallic oxalate complexes and tetrathiafulvalene molecules: Synthesis, structure, and m…

1996

Application of Bioaugmentation to Improve Pharmaceutical Wastewater Treatment Efficiency

2019

Ecological harm and human health risks caused by environmental pollution with active pharmaceutical ingredients (API) nowadays is recognised as issue of growing concern. Widespread presence of human and veterinary API in aquatic environment clearly indicates persistence and low removal efficiency of these compounds at conventional pharmaceutical and municipal wastewater treatment plants (WWTP). Bioaugmentation of activated sludge systems with specialized microorganisms could be a powerful and environmentally friendly tool to enhance the removal efficiency of recalcitrant API. Selection of inoculum strains, that have appropriate enzymatic pathways to metabolise complex molecules of API, belo…