Search results for "dam"
showing 10 items of 3828 documents
The Employment of Unmanned Aerial Vehicles for Analyzing and Mitigating Disaster Risks in Industrial Sites
2020
Effective safety procedures play a fundamental role in high-risk industrial contexts, because the occurrence of an accident can cause environmental catastrophes, severe damages to the structures, and fatal injuries to the workers. In particular, maintaining detailed and up-to-date information about potential accident areas is a crucial issue to prevent the occurrence of disasters and to safely plan the rescue process. In such contexts, periodic safety inspections are therefore performed on a regular basis, although they may expose the inspection personnel to harsh or hazardous environments. The employment of unmanned aerial vehicles (UAVs) in such situations can provide unprecedented opport…
Las sociedades arrendatarias de los impuestos municipales de Valencia (1410-1450)
2017
La ciudad de Valencia había consolidado su sistema fiscal a finales del siglo XIV. El arrendamiento de los impuestos indirectos desempeñó un papel clave en ese sistema, mediante un procedimiento de subasta pública. Durante la primera mitad del siglo XV, se confirmaron dos procesos relacionados: la monopolización de los arrendamientos por parte de una élite financiera, que a la vez retenía los cargos contables municipales; y la tendencia a la baja de los precios de los arrendamientos, en detrimento del sistema económico municipal. La combinación de documentación pública y privada permite ampliar el conocimiento sobre la organización de aquellas sociedades arrendatarias. The city of Valencia …
Smith, Marshall and Young on division of labour and economic growth
2003
The aim of this paper is to reconstruct the theory of division of labour and economic growth proposed by Adam Smith and developed by Alfred Marshall and Allyn Young. In their approach division of labour is the main engine of growth and plays a central role in capital accumulation and technological progress. We suggest that, according to their theory: 1) economic growth is endogenous; 2) it has the nature of a cumulative, pathdependent process; and 3) it can be described as a disequilibrium process, supported by competitive forces. We argue that these aspects make the contributions of Smith, Marshall and Young still insightful for the development of growth theory, even in the light of the mo…
Flotillin-involved uptake of silica nanoparticles and responses of an alveolar-capillary barrier in vitro
2013
AbstractDrug and gene delivery via nanoparticles across biological barriers such as the alveolar-capillary barrier of the lung constitutes an interesting and increasingly relevant field in nanomedicine. Nevertheless, potential hazardous effects of nanoparticles (NPs) as well as their cellular and systemic fate should be thoroughly examined. Hence, this study was designed to evaluate the effects of amorphous silica NPs (Sicastar) and (poly)organosiloxane NPs (AmOrSil) on the viability and the inflammatory response as well as on the cellular uptake mechanisms and fate in cells of the alveolar barrier. For this purpose, the alveolar epithelial cell line (NCI H441) and microvascular endothelial…
TIO2 brookite: Properties, synthesis and applications
2017
Brookite is one of the less studied polymorphic phases of titanium dioxide. Indeed, synthetic procedures affording brookite as a pure phase were not straightforward and have been only recently optimized. For this reason, brookite has received particular attention in the last years, especially as a promising photocatalytic material for environmental remediation and for the synthesis of valuable organic products. The present chapter will review the main synthetic methods reported in literature to produce brookite as a pure phase or mixed with rutile and/or anatase. Morphological, structural and electronic properties both of pure or variously modified brookite will be presented. The particular…
Hydraulic Models and Finite Elements for Monitoring of an Earth Dam, by Using GNSS Techniques
2016
This work gives a comparison between different mathematicalmodels for the evaluation of the movements of an earthendam situated between Bivona and Alessandria della Rocca, inthe province of Agrigento (AG), Italy. The models selected areof a hydraulic nature, already tested on concrete dams, andfinite elements models which, on the contrary, exploit geotechnicalparameters. The results obtained from the comparisonof the displacement planimetric components and the relativetime series of data over a period of two years appear to befully satisfactory, in fact using both models of a hydraulic andgeotechnical nature, we reach residues of just mm. To supportthis work, a monitoring procedure using GN…
New approach for harmonic mitigation in single-phase five-level CHBMI with fundamental frequency switching
2017
The main objective of this paper is to study and analyse the voltage output waveform of a multilevel inverter, to suggest a new approach for harmonic mitigation improving the converter performance. These last type of converters represent a new technology in the field of DC/AC electrical energy conversion, presenting advantages respect to the traditional converters. In fact, the multilevel power converters present a low harmonic content and a high voltage level. The paper considers a five-level single-phase cascaded H-bridge inverter and fundamental frequency modulation techniques. The voltage waveform analysis has allowed to identify a working area of the converter where there are lowest va…
A frequency compensation algorithm of four-wheel coherence random road
2013
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/986584 Open access The road surface roughness is the main source of kinematic excitation of a moving vehicle, which has an important influence on vehicle performance. In recent decades, random road models have been widely studied, and a four-wheel random road time domain model is usually generated based on the correlation of the four-wheel input, in which a coherence function is used to describe the coherence of the road input between the left and right wheels usually. However, during our research, there are some conditions that show that…
Seismic response of braced frames with and without friction dampers
1995
Abstract The dynamic response of friction damped bracing systems and ordinary cross-bracing systems inserted into surrounding frames without lateral stiffness is analysed in order to compare the typical behaviour of the two different bracing systems. The cyclic force-displacement relationship in the two cases is accurately modelled on the basis of experimental and related numerical models which are available in the literature, and the structural dimensionless parameters defining the shapes of the cycles are stressed. Systems having the same average period of vibration in the elastic phase of the response are assumed to be comparable with one another, which leads to a relationship linking th…
Viscoelastic bearings with fractional constitutive law for fractional tuned mass dampers
2015
Abstract The paper aims at studying the effects of the inherent fractional constitutive law of viscoelastic bearings used as devices for tuned mass dampers. First, the proper constitutive law of the viscoelastic supports is determined by the local constitutive law. Then, the characteristic force–displacement relationship at the top of the bearing is found. Taking advantage of the whole bearing constitutive laws, the tuning of the mass damper is proposed by defining the damped fractional frequency, which is analogous to the classical damped frequency. The effectiveness of the optimal tuning procedure is validated by a numerical application on a system subjected to a Gaussian white noise.