Numerical study of two-dimensional moist symmetric instability

The 2-D version of the non-hydrostatic fully compressible model MOLOCH developed at ISAC-CNR was used in idealized set-up to study the start-up and finite amplitude evolution of symmetric instability. The unstable basic state was designed by numerical integration of the equation which defines saturated equivalent potential vorticity q<sub>e</sub><sup>*</sup>. We present the structure and growth rates of the linear modes both for a supersaturated initial state ("super"-linear mode) and for a saturated one ("pseudo"-linear mode) and the modifications induced on the base state by their finite amplitude evolution

Numerical study of a banded precipitation event over Italy

Satellite images of 30 October 2008 show the development over north-central Italy of rainbands and multiple waves during a strong south-westerly wind episode associated with a deepening synoptic trough and cold front passage. The event was studied by means of the ISAC model chain constituted of the hydrostatic model BOLAM and the nested non-hydrostatic model MOLOCH at 1.1 km resolution. Diagnostics of model output was performed to reveal the physical origin of the dynamical features and precipitation field as simulated. Based on our results we propose a theoretical framework in which symmetric instability underlies some of the observed precipitation patterns

A Method for Generating a Well-Distributed Pareto Set in Nonlinear Multiobjective Optimization

A method is presented for generating a well-distributed Pareto set in nonlinear multiobjective optimization. The approach shares conceptual similarity with the Physical Programming-based method, the Normal-Boundary Intersection and the Normal Constraint methods, in its systematic approach investigating the objective space in order to obtain a well-distributed Pareto set. The proposed approach is based on the generalization of the class functions which allows the orientation of the search domain to be conducted in the objective space. It is shown that the proposed modification allows the method to generate an even representation of the entire Pareto surface. The generation is performed for both convex and nonconvex Pareto frontiers. A simple algorithm has been proposed to remove local Pareto solutions. The suggested approach has been verified by several test cases, including the generation of both convex and concave Pareto frontiers

Case Report: Coexistence of SUNCT and Hypnic Headache in the Same Patient

Background: Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and hypnic headache (HH) are two exceedingly rare and distinctly classified primary headaches. The hypothalamus seems to be a crucial region involved in the pathophysiology of both conditions, but no cases of SUNCT and HH co-occurrence have been described so far. Case results: A 49-year-old woman who has been suffering from SUNCT for years, with alternation of symptomatic periods and remissions, developed a new headache with different clinical features, presenting exclusively during sleep and with a dramatic responsiveness to caffeine, that met the diagnostic criteria for HH. Conclusions: The available literature suggests that SUNCT and HH are different conditions but the association in the same patient that we describe supports the concept that they are not mutually exclusive. Further studies are needed to establish if they share a common pathophysiological mechanism

Raman excitation spectroscopy of carbon nanotubes: effects of pressure medium and pressure

Raman excitation and emission spectra for the radial breathing mode (RBM) are reported, together with a preliminary analysis. From the position of the peaks on the two-dimensional plot of excitation resonance energy against Raman shift, the chiral indices (m, n) for each peak are identified. Peaks shift from their positions in air when different pressure media are added - water, hexane, sulphuric acid - and when the nanotubes are unbundled in water with surfactant and sonication. The shift is about 2 - 3 cm-1 in RBM frequency, but unexpectedly large in resonance energy, being spread over up to 100meV for a given peak. This contrasts with the effect of pressure. The shift of the peaks of semiconducting nanotubes in water under pressure is orthogonal to the shift from air to water. This permits the separation of the effects of the pressure medium and the pressure, and will enable the true pressure coefficients of the RBM and the other Raman peaks for each (m, n) to be established unambiguously.Comment: 6 pages, 3 Figures, Proceedings of EHPRG 2011 (Paris

3D MODELLING OF THE NEGRO TOWER FOR ITS COMPREHENSIVE ANALYSIS AND A CONSERVATION PROPOSAL

Abstract. The Negro Tower, in El Algar, Cartagena (Region of Murcia, Spain), is a building which dates to 1585. It is a tower built in a rural environment, inland from the coast, to alert and protect the population from pirate attacks. It was part of the network of watchtowers and defense posts along the coast of Murcia built between the sixteenth and seventeenth centuries. The tower is protected as a historical monument, but its state of conservation is very poor. For this reason, a comprehensive study has been carried out to ensure its correct restoration and future conservation. Historical and constructive analysis has allowed us to discover the social, cultural and architectural characteristics of the tower. Digital photogrammetry and 3D laser scanning compatible with classic topography have been used for the graphic survey of the tower. All this information has permitted the elaboration of thorough three-dimensional modelling and the proposal of a volumetric recomposition of the tower. The presentation will set out the working methodology followed as well as the important results achieved. This research work aims to contribute to the recognition and correct conservation of the Tower. The graphic survey and the three-dimensional model obtained will allow the recovery of the tower and its integration into the natural environment

Enabling Cloud-based Computational Fluid Dynamics with a Platform-as-a-Service Solution

Computational Fluid Dynamics (CFD) is widely used in manufacturing and engineering from product design to testing. CFD requires intensive computational power and typically needs high performance computing to reduce potentially long experimentation times. Dedicated high performance computing systems are often expensive for small-to-medium enterprises (SMEs). Cloud computing claims to enable low cost access to high performance computing without the need for capital investment. The CloudSME Simulation Platform aims to provide a flexible and easy to use cloud-based Platform-as-a-Service (PaaS) technology that can enable SMEs to realize the benefits of high performance computing. Our Platform incorporates workflow management and multi-cloud implementation across various cloud resources. Here we present the components of our technology and experiences in using it to create a cloud-based version of the TransAT CFD software. Three case studies favourably compare the performance of a local cluster and two different clouds and demonstrate the viability of our cloud-based approach