Post-test simulations for the NACIE-UP benchmark by STH codes

This paper illustrates the results obtained in the last phase of the NACIE-UP benchmark activity foreseen inside the EU SESAME Project. The purpose of this research activity, performed by system thermal–hydraulic (STH) codes, is finalized to the improvement, development and validation of existing STH codes for Heavy Liquid Metal (HLM) systems. All the participants improved their modelling of the NACIE-UP facility, respect to the initial blind simulation phase, adopting the actual experimental boundary conditions and reducing as much as possible sources of uncertainty in their numerical model. Four different STH codes were employed by the participants to the benchmark to model the NACIE-UP facility, namely: CATHARE for ENEA, ATHLET for GRS, RELAP5-3D© for the “Sapienza” University of Rome and RELAP5/Mod3.3(modified) for the University of Pisa. Three reference tests foreseen in the NACIE-UP benchmark and carried out at ENEA Brasimone Research Centre were analysed from four participants. The data from the post-test analyses, performed independently by the participant using different STH codes, were compared together and with the available experimental results and critically discussed

Wavelet maxima curves of surface latent heat flux associated with two recent Greek earthquakes

International audienceMulti sensor data available through remote sensing satellites provide information about changes in the state of the oceans, land and atmosphere. Recent studies have shown anomalous changes in oceans, land, atmospheric and ionospheric parameters prior to earthquakes events. This paper introduces an innovative data mining technique to identify precursory signals associated with earthquakes. The proposed methodology is a multi strategy approach which employs one dimensional wavelet transformations to identify singularities in the data, and an analysis of the continuity of the wavelet maxima in time and space to identify the singularities associated with earthquakes. The proposed methodology has been employed using Surface Latent Heat Flux (SLHF) data to study the earthquakes which occurred on 14 August 2003 and on 1 March 2004 in Greece. A single prominent SLHF anomaly has been found about two weeks prior to each of the earthquakes

Cognitive conflicts in major depression : Between desired change and personal coherence

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposesThe notion of intrapsychic conflict has been present in psychopathology for more than a century within different theoretical orientations. However, internal conflicts have not received enough empirical attention, nor has their importance in depression been fully elaborated. This study is based on the notion of cognitive conflict, understood as implicative dilemma (ID), and on a new way of identifying these conflicts by means of the Repertory Grid Technique. Our aim was to explore the relevance of cognitive conflicts among depressive patientsPeer reviewedFinal Published versio

Setup of a High-Speed Optical System for The Characterization of Cavitation Instabilities in Space Rocket Turbopumps

The present paper illustrates the set-up and the preliminary results of an experimental investigation of cavitation flow instabilities carried out by means of a high-speed camera on a three bladed inducer in the CPRTF (Cavitating Pump Rotordynamic Test Facility) at Alta S.p.A. The brightness thresholding technique adopted for cavitation recognition is described and implemented in a semi-automatic algorithm. In order to test the capabilities of the algorithm, the mean frontal cavitating area has been computed under different operating conditions. The tip cavity length has also been evaluated as a function of time. Inlet pressure signal and video acquisitions have been synchronized in order to analyze possible cavitation fluid-dynamic instabilities both optically and by means of pressure fluctuation analysis. Fourier analysis showed the occurrence of a cavity length oscillation at ..

A new dry deposition model implemented in CALPUFF code to simulate contamination of radionuclides released into atmospheric environment post-nuclear accidental event

Long-range transport and deposition analyses of 137Cs following a hypothetical incident at Gösgen nuclear power plant are studied by using CALMET-CALPUFF model system. Comparisons are performed with results obtained from a version modified of CALPUFF using a new dry deposition velocity model. This model is based on a combination of aerodynamic resistances and considers local features of the mutual influence of inertial impact and turbulent processes. The results show that the modified CALPUFF code seems to be an appropriate tool for performing impact assessments on long-range transport in complex terrain contexts or to support preparedness and response capabilities for nuclear and radiological accidents

Role of Anomalous Warm Gulf Waters in the Intensification of Hurricane Katrina

The year 2005 experienced several strong hurricanes intensifying in the Gulf of Mexico before making landfall that severely damaged the Gulf States, especially Hurricane Katrina. Remarkable similarities between sea surface temperature anomaly (SSTA) and major hurricane (categories 3 and higher) activity over the Gulf are identified. However, the intensification of individual hurricanes may not necessarily be temporally and spatially coincident with the distribution of warm waters or high sea surface temperature (SST). High SST values are found in advance of significant intensification of Hurricane Katrina. We emphasize that high SSTA which occurred at the right time and right place was conducive to the hurricane intensification. In particular, high SSTA in the northeastern quadrant of the storm track induced significant increases in surface latent heat fluxes (LHF) contributing to the rapid intensification of Katrina. We also compared and verified model simulations with buoy observations

A Reduced Order Model for Preliminary Design and Performance Prediction of Tapered Inducers: Comparison with Numerical Simulations

The article recalls the recent development of a reduced order model for the preliminary design, geometric definition and noncavitating performance prediction of tapered-hub, variable-pitch, mixed-flow inducers, and illustrates its application to a typical three-bladed, high-head inducer for liquid propellant rocket engines. The mean axisymmetric flow field at the trailing edge of the inducer blades and the noncavitating head coefficient at both design and off-design conditions are then compared with those obtained from the numerical flow simulations generated by a commercial CFD code. Together with earlier experimental validations, the results dramatically confirm the capability of the proposed model to generate interpretative and useful engineering solutions of the inducer preliminary design problem at a negligible fraction of the computational cost required by 3D numerical simulations

Mental fortitude training: An evidence-based approach to developing psychological resilience for sustained success

Drawing on the body of knowledge in this area, this article presents an evidence-based approach to developing psychological resilience for sustained success. To this end, the narrative is divided into three main sections. The first section describes the construct of psychological resilience and explains what it is. The second section outlines and discusses a mental fortitude training™ program for aspiring performers. The third section provides recommendations for practitioners implementing this program. It is hoped that this article will facilitate a holistic and systematic approach to developing resilience for sustained success