Search results for "conservation."

The façade-tower of Santa Maria delle Stelle Church in Comiso. Historical events, vulnerability and conservation strategy

2020

Dopo avere richiamato l’estesa vicenda storica della costruzione della chiesa Madre di Santa Maria delle Stelle a Comiso, iniziata nel 1736 e terminata due secoli dopo, il contributo è focalizzato sul tema del completamento della sua facciata con l’uso della struttura intelaia di calcestruzzo di cemento armato, progettata dall’ingegnere Santoro Secolo. In tempi più recenti, alcuni dissesti improvvisi hanno posto in evidenza il tema del rischio e la necessità di interventi per risanare la struttura architettonica. L’importanza del monitoraggio e della manutenzione, intesi come fondamentali strategie di conservazione, concludono l’articolo.

Contrasting behavioural responses of two egg parasitoids to buckwheat floral scent is reflected in field parasitism rates

2017

The use of food supplements in conservation biological control (CBC) programmes is considered an essential element for increasing parasitoid fitness and their population density leading to an increase in overall parasitism levels. However, non-crop habitats that substitute the necessary resources for natural enemies have not always achieved the desired effects. It is suggested that the composition of flower strips in agricultural systems around/in agricultural fields plays an important role because not all plant species are equally suitable and the consumption of food resources by parasitoids can shape direct and indirect interactions with other arthropods and the community complex. We deve…

Local Total Variation Bounded Methods for Hyperbolic Conservation Laws

2003

Solving a model for 1-D, three-phase flow vertical equilibrium processes in a homogeneous porous medium by means of a Weighted Essentially Non Oscill…

2013

Mathematical models of multi-phase flow are useful in some engineering applications like enhanced oil recovery, filtration of pollutants into subsurface, etc. In this work, we derive a mathematical model for the motion of one-dimensional three-phase flow in a porous medium under the condition of vertical equilibrium, which can be viewed as an extension of some two-phase flow models described in the literature. Our model involves a system of two partial differential equations in the form of viscous conservation laws, whose solutions may contain very sharp transitions. We show that a high-order/high resolution Weighted Essentially Non Oscillatory scheme is an appropriate tool to discretize th…

On a new centered strategy to control the accuracy of weighted essentially non oscillatory algorithm for conservation laws close to discontinuities

2020

Some techniques for improving the resolution of finite difference component-wise WENO schemes for polydisperse sedimentation models

2014

Polydisperse sedimentation models can be described by a system of conservation laws for the concentration of each species of solids. Some of these models, as the Masliyah-Locket-Bassoon model, can be proven to be hyperbolic, but its full characteristic structure cannot be computed in closed form. Component-wise finite difference WENO schemes may be used in these cases, but these schemes suffer from an excessive diffusion and may present spurious oscillations near shocks. In this work we propose to use a flux-splitting that prescribes less numerical viscosity for component-wise finite difference WENO schemes. We compare this technique with others to alleviate the diffusion and oscillatory be…

A numerical treatment of wet/dry zones in well-balanced hybrid schemes for shallow water flow

2012

The flux-limiting technology that leads to hybrid, high resolution shock capturing schemes for homogeneous conservation laws has been successfully adapted to the non-homogeneous case by the second and third authors. In dealing with balance laws, a key issue is that of well-balancing, which can be achieved in a rather systematic way by considering the 'homogeneous form' of the balance law.The application of these techniques to the shallow water system requires also an appropriate numerical treatment for the wetting/drying interfaces that appear initially or as a result of the flow evolution. In this paper we propose a numerical treatment for wet/dry interfaces that is specifically designed f…

Magnetic fields in heavy ion collisions: flow and charge transport

2020

At the earliest times after a heavy-ion collision, the magnetic field created by the spectator nucleons will generate an extremely strong, albeit rapidly decreasing in time, magnetic field. The impact of this magnetic field may have detectable consequences, and is believed to drive anomalous transport effects like the Chiral Magnetic Effect (CME). We detail an exploratory study on the effects of a dynamical magnetic field on the hydrodynamic medium created in the collisions of two ultrarelativistic heavy-ions, using the framework of numerical ideal MagnetoHydroDynamics (MHD) with the ECHO-QGP code. In this study, we consider a magnetic field captured in a conducting medium, where the conduc…

Effect of Demand Side Management on the Operation of PV-Integrated Distribution Systems

2020

In this new era of high electrical energy dependency, electrical energy must be abundant and reliable, thus smart grids are conducted to deliver load demands. Hence, smart grids are implemented alongside distributed generation of renewable energies to increase the reliability and controllability of the grid, but, with the very volatile nature of the Distributed Generation (DG), Demand Side Management (DSM) helps monitor and control the load shape of the consumed power. The interaction of DSM with the grid provides a wide range of mutual benefits to the user, the utility and the market. DSM methodologies such as Conservation Voltage Reduction (CVR) and Direct Load Control (DLC) collaborate i…

A multi-domain approach for smoothed particle hydrodynamics simulations of highly complex flows

2018

Abstract An efficient and accurate method is proposed to solve the incompressible flow momentum and continuity equations in computational domains partitioned into subdomains in the framework of the smoothed particle hydrodynamics method. The procedure does not require any overlap of the subdomains, which would result in the increase of the computational effort. Perfectly matching solutions are obtained at the surfaces separating neighboring blocks. The block interfaces can be both planar and curved surfaces allowing to easily decompose even geometrically complex domains. The smoothing length of the kernel function is maintained constant in each subdomain, while changing between blocks where…