Search results for "External"
showing 10 items of 601 documents
Brick Masonry Columns Externally Wrapped with Steel Wires under Concentric and Eccentric Loads
2017
This paper discusses an experimental investigation of clay brick columns that are externally strengthened by steel wire collars wrapping the horizontal mortar joints. The study aims to prove the effectiveness of the proposed strengthening technique and detect the efficiency of different numbers of steel collars. Additionally, the effect of eccentric loading is investigated. This paper proves that an analytical expression available in the previous literature can be modified to provide the strength of the equivalent homogeneous cross section in simple compression. To this aim, the biaxial strength domain of the bricks is modified to account for the lateral pressure exerted by the steel collar…
Shear-aligned block copolymer monolayers as seeds to control the orientational order in cylinder-forming block copolymer thin films
2016
We study the dynamics of coarsening of a cylinder-forming block copolymer thin film deposited on a prepatterned substrate made of a well-ordered block copolymer monolayer. During thermal annealing the shear-aligned bottom layer drives extinction of the disclinations and promotes a strong orientational correlation, disturbed only by dislocations and undulations along the cylinders of the minority phase. The thin film bilayer system remains stable during annealing, in agreement with self-consistent field theory results that indicate that although the thickness of a stack of two monolayers is not at the optimum thickness condition, it is very close to equilibrium. Phase field simulations indic…
Analysis of multipactor RF breakdown in a waveguide containing a transversely magnetized ferrite
2016
In this paper, the multipactor RF breakdown in a parallel-plate waveguide partially filled with a ferrite slab magnetized normal to the metallic plates is studied. An external magnetic field is applied along the vertical direction between the plates in order to magnetize the ferrite. Numerical simulations using an in-house 3-D code are carried out to obtain the multipactor RF voltage threshold in this kind of structures. The presented results show that the multipactor RF voltage threshold at certain frequencies becomes considerably lower than for the corresponding classical metallic parallel-plate waveguide with the same vacuum gap
Investigation on Application of Basalt Materials as Reinforcement for Flexural Elements of Concrete Bridges
2015
Basalt polymers are rather new materials for civil engineering; therefore, identification of peculiarities and limitations of application of such polymers in concrete structures (particularly bridges) is of vital importance. This paper experimentally investigates deformation behaviour and cracking of flexural elements, which are predominant parameters governing serviceability of the bridges. Unlike a common practice, the present study is not limited by the analysis of concrete beams reinforced with the polymer bars; it also considers effectiveness of basalt fibre reinforced polymer sheets for repairing the beams. The analysis has revealed that a combination of the high strength and elastici…
Optimal Sizing and Siting of Distributed Energy Resources Considering Public and Private Incentive Policies
2008
The present work presents the formulation and solution approach for the problem of optimal sizing and siting of distributed energy resources based on Photovoltaic, PV, technology. The considered system is an isolated grid (small island) and the parts involved are the utility and the customers. As it happens in islands, the same utility generates and delivers energy to customers, for this reason, the installation of dispersed generation units is beneficial for reducing power losses, regularizing the voltage profile, but also for increasing the profit. The problem is solved by means of the Non dominated sorting Genetic Algorithm II, NSGA-II, identifying the optimal size and location of PV sys…
A four-node MITC finite element for magneto-electro-elastic multilayered plates
2013
An isoparametric four-node finite element for multilayered magneto-electro-elastic plates analysis is presented. It is based on an equivalent single-layer model, which assumes the first order shear deformation theory and quasi-static behavior for the electric and magnetic fields. First, the electro-magnetic state of the plate is determined in terms of the mechanical primary variables, namely the generalized displacements, by solving the strong form of the magneto-electric governing equations coupled with the electro-magnetic interface continuity conditions and the external boundary conditions. In turn, this result is used into the layers constitutive law to infer the equivalent single-layer…
Developmental dynamics between children’s externalizing problems, task-avoidant behavior, and academic performance in early school years: A 4-year fo…
2015
This longitudinal study investigated the associations among children’s externalizing problems, task-avoidant behavior, and academic performance in early school years. The participants were 586 children (43% girls, 57% boys). Data pertaining to externalizing problems (teacher ratings) and task-avoidant behaviors (mother and teacher ratings) were gathered, and the children were tested yearly on their academic performance in Grades 1–4. The results were similar for both genders. The analyses supported a mediation model: high externalizing problems in Grades 1 and 2 were linked with low academic performance in Grades 3 and 4 through increases in task-avoidant behavior in Grades 2 and 3. The res…
Validación y verificación analítica de los métodos microbiológicos
2015
Clinical microbiologists should ensure, to the maximum level allowed by the scientific and technical development, the reliability of the results. This implies that, in addition to meeting the technical criteria to ensure their validity, they must be performed with a number of conditions that allows comparable results to be obtained, regardless of the laboratory that performs the test. In this sense, the use of recognized and accepted reference methodsis the most effective tool for these guarantees. The activities related to verification and validation of analytical methods has become very important, as there is continuous development, as well as updating techniques and increasingly complex …
Complementary Consumer Responsibility - The Limits to Immoral Delegation in Markets
2019
Delegation has been shown to facilitate individual immoral behavior. It is however unclear, if these findings extend to markets, where consumers may punish firms who delegate immoral production decisions. I address this question by employing an experimental market paradigm, involving an unfair product, containing a negative externality, and a fair product without externality. Passive delegation of the production decision, with random matching between an owner and a seller, leads to a lower share of the fair product being traded, consistent with the findings on responsibility diffusion. Active delegation in contrast, where owners have a choice over sellers first, increases the share of the f…
Returns to scale in a matching model: evidence from disaggregated panel data
2005
The returns to scale in the matching function play an important role in models with endogenous search effort. Due to positive externalities, increasing returns to scale in matching can support high or low activity equilibrium in the labour market. In this study, we examine this issue using panel data from Finnish employment offices. The study finds that the results from the Cobb–Douglas and translog specification are qualitatively different. The CD specification of the matching function exhibits constant returns to scale. The translog specification, in turn, exhibits increasing returns to scale. The elasticity estimate for returns, using the preferred specification and minimum and maximum s…