Search results for "flow [Keywords]"
showing 10 items of 469 documents
Multithreaded Translation of Ptolemy II Designs on Multicore Platforms
2008
Ptolemy II is an open source environment for system design and test based on component data flow. This paradigm tries to make parallel systems more deterministic and understandable. In this work we propose a technique to translate designs developed with Ptolemy II, into multithreaded Java implementations on multicore platforms. We have chosen Java mainly because Ptolemy II is implemented in Java and then we get direct code reuse. The counterpart is a certain amount of overhead that we expect to be less relevant as Java runtime environment will evolve. The main goals are to produce efficient parallel simulators and software devices with competitive performance level. We show by means of an e…
Coronary Artery Shape and Flow Changes Induced by Myocardial Bridging.
1993
Changes in coronary shape and blood flow induced by myocardial bridging were analyzed in a 56-year-old patient with symptoms of unstable angina after the exclusion of other heart disease. Coronary angiography demonstrated a 1.8-cm long myocardial bridge in the middle part of the left anterior descending coronary artery. In systole, an eccentric compression of the artery occurred, resulting in a stenosis that occupied 86% of the diameter and 96% of the area. Intraluminal ultrasound was performed with a 20-MHz transducer in a 4.8-Fr catheter sheath (Boston Scientific Corp.) connected to an ultrasound console (Diasonics Inc.). A side saddle catheter was introduced into the left anterior descen…
Dynamic Mechanical Measurements of Epoxy Matrix-Silica Nanocomposites II
2009
The mechanical properties of epoxy-silica nanocomposites have been studied; the silica nanosphere fillers used were un-functionalised, functionalised with amine, with epoxy, or a mixture of both kinds. Dynamic mechanical analysis measurements revealed an increase in the shear storage modulus, for all samples with a filler content of 3–5%. Improvements were observed in the glassy and rubbery states, without affecting the glass transition temperature of the materials. Above these strengthening percentages, the mechanical properties began to deteriorate, but in all cases they remained superior to those of the pristine epoxy resin. For low strengthening percentages, samples reinforced with bot…
Economic analysis of the scale-up and implantation of a hollow fibre membrane contactor plant for nitrogen recovery in a full-scale wastewater treatm…
2021
[EN] Nitrogen recovery technologies such as the hollow fibre membrane contactor are now being developed. However, an economic analysis is needed prior to their full-scale application in wastewater treatment plants. The aim of this study was to analyse the economic and environmental aspects of scaling-up this method. To achieve it, a full-scale 40,000 m3·day¿1-wastewater treatment plant influent flow rate was simulated jointly with a membrane contactor plant to evaluate the minimum costs of optimum operating conditions of membrane contactors (pH, feed flow rate and membrane surface). The optimum conditions for treating 600 m3·day¿1 of reject water was found to be 10 pH, 0.08 m3·s¿1 feed flow…
DNP in MRI: an in-bore approach at 1.5 T.
2011
Abstract We have used liquid state (“Overhauser”) Dynamic Nuclear Polarization (DNP) to significantly enhance the signal to noise ratio (SNR) of Magnetic Resonance Imaging (MRI). For the first time this was achieved by hyperpolarizing directly in the MRI-scanner field of 1.5 T in continuous flow mode and immediately delivering the hyperpolarized substance to the imaging site to ensure maximum contrast between hyperpolarized sample and sample at thermal polarization. We achieve a maximum absolute signal enhancement factor of 98; while the hyperpolarized sample is transported at a flow rate of up to 30 ml/h yielding an average flow speed up to 470 mm/s over a distance of approximately 80 mm. …
The NA48 event-building PC farm
2003
The NA48 experiment at the CERN SPS aims to measure the parameter $\Re(\epsilon'/ \epsilon)$ of direct CP violation in the neutral kaon system with an accuracy of $2 \times 10^{-4}$. Based on the requirements of: \\\\ * high event rates (up to 10 kHz) with negligible dead time;\\ * support for a variety of detectors with very wide variation in the number of readout channels;\\ * data rates of up to 150 MByte/s sustained over the beam burst;\\ * level-3 filtering and remote data logging in the CERN computer center; \\\\ the collaboration has designed and built a modular pipelined data flow system with 40 MHz sampling rate. The architecture combines custom-designed components with commerciall…
A semi-empirical approach for predicting two-phase flow discharge through branches of various orientations connected to a horizontal main pipe
2010
Abstract The subdivision of two-phase flow in branching conduits consisting of a large horizontal main pipe with upward, downward, or lateral branches of reduced diameter is of great interest in various technological fields. For example, these conduits are important in light-water nuclear reactors (LWRs) in the case of a small break loss-of-coolant accident (SBLOCA) in a leg of the reactor's primary coolant loops, as well as for breaks or valve malfunctions in a large pipeline. In these kinds of circumstances, the relevant phenomenology often involves phase stratification coupled with possible liquid entrainment or gas pool-through phenomena. Therefore, these phenomena were studied in depth…
The Argo YBJ daq system and the GRID based data transfer
2008
The Argo-YBJ experiment has now reached itsfinal design configuration. The detector system consists of a fullcoverage array (about 5800 square meters) of Resistive PlateChambers (RPCs). The throughput depends on the trigger rateand threshold. The DAQ system must be able to sustain a max-imum transfer rate of the order of 15 MB/s and a high peakdata flow. Data are read out using a typical front-end acquisitionchain built around a custom bus. Specialized electronics have beendesigned and dedicated software has been written to perform thistask. Data are sent to the online farm through a switch exploitinga gigabit ethernet protocol. A solution to transfer data from theYBJ laboratory to the labo…
On the numerical assessment of the thermal-hydraulic operating map of the DEMO Divertor Plasma Facing Components cooling circuit
2020
Abstract Within the framework of the Work Package DIV 1 - “Divertor Cassette Design and Integration” of the EUROfusion action, a research campaign has been jointly carried out by University of Palermo and ENEA to investigate the thermal-hydraulic behaviour of the DEMO divertor cassette cooling system, focussing the attention on the 2018 configuration of the Plasma Facing Components (PFCs) circuit consistent with the DEMO baseline 2017. The research campaign has been carried out following a theoretical-computational approach based on the finite volume method and adopting the commercial Computational Fluid-Dynamic (CFD) code ANSYS CFX. A steady-state CFD analysis has been carried out for the …
A marching in space and time (MAST) solver of the shallow water equations. Part II: The 2D model
2007
Abstract A novel methodology for the solution of the 2D shallow water equations is proposed. The algorithm is based on a fractional step decomposition of the original system in (1) a convective prediction, (2) a convective correction, and (3) a diffusive correction step. The convective components are solved using a Marching in Space and Time (MAST) procedure, that solves a sequence of small ODEs systems, one for each computational cell, ordered according to the cell value of a scalar approximated potential. The scalar potential is sought after computing first the minimum of a functional via the solution of a large linear system and then refining locally the optimum search. Model results are…