Search results for " impianti nucleari"
showing 10 items of 413 documents
Measurement of long-lived radionuclide activity induced in target components of a cyclotron used for [18F ]-[FDG] production
2019
The evaluation of high activity induced in target components in using a medical cyclotron to produce positron-emitting radionuclides for PET (Positron Emission Tomography) diagnostic studies is one of important issue and involves radiation protection concepts when operators are engaged in maintenance and/or substitution of a target or its components. Most of replaced target components are generally classified and stored in a Pb-shielded container in order to wait for their radioactive decay. However, after some years, it can be necessary to start with the removal of the oldest parts, for a temporary storage of the fresh activated ones. The feasibility of these operations and the waste final…
Qualifica di codici di calcolo dedicati alle analisi di sistema avanzati quando applicati nella simulazione di impianti a metallo liquido
2013
Applicazione della tecnica HFMEA in radioterapia
2014
Pressure-Induced Deformation of Pillar-Type Profiled Membranes and Its Effects on Flow and Mass Transfer
2019
In electro-membrane processes, a pressure difference may arise between solutions flowing in alternate channels. This transmembrane pressure (TMP) causes a deformation of the membranes and of the fluid compartments. This, in turn, affects pressure losses and mass transfer rates with respect to undeformed conditions and may result in uneven flow rate and mass flux distributions. These phenomena were analyzed here for round pillar-type profiled membranes by integrated mechanical and fluid dynamics simulations. The analysis involved three steps: (1) A conservatively large value of TMP was imposed, and mechanical simulations were performed to identify the geometry with the minimum pillar density…
k-epsilon Predictions of Heat Transfer in Turbulent Recirculating Flows Using an Improved Wall Treatment
1989
Recent Progress in the WCLL Breeding Blanket Design for the DEMO Fusion Reactor
2018
The water-cooled lithium-lead (PbLi) breeding blanket is one of the candidate systems considered for the implementation in the European Demonstration Power Plant (DEMO) nuclear fusion reactor. This concept employs PbLi liquid metal as tritium breeder and neutron multiplier, water pressurized at 15.5 MPa as the coolant, and EUROFER as the structural material. The current design is based on the single module segment approach and follows the requirements of the DEMO-2015 baseline design. The module is constituted by a basic toroidal-radial cell that is recursively repeated along the poloidal direction where the liquid metal flows along a radial-poloidal path. The heat generated by the fusion r…
A GENERAL COMPUTATIONAL APPROACH FOR MAGNETOHYDRODYNAMIC FLOWS USING THE CFX CODE: BUOYANT FLOW THROUGH A VERTICAL SQUARE CHANNEL
2000
The buoyancy-driven magnetoconvection in the cross section of an infinitely long vertical square duct is investigated numerically using the CFX code package. The implementation of a magnetohydrodynamic (MHD) problem in CFX is discussed, with particular reference to the Lorentz forces and the electric potential boundary conditions for arbitrary electrical conductivity of the walls. The method proposed is general and applies to arbitrary geometries with an arbitrary orientation of the magnetic field. Results for fully developed flow under various thermal boundary conditions are compared with asymptotic analytical solutions. The comparison shows that the asymptotic analysis is confirmed for hi…
A Review of Healthcare Failure Mode and Effects Analysis (HFMEA) in Radiotherapy
2016
This paper presents a review of risk analyses in radiotherapy (RT) processes carried out by using Healthcare Failure Mode Effect Analysis (HFMEA) methodology, a qualitative method that proactively identifies risks to patients and corrects medical errors before they occur. This literature review was performed to provide an overview of how to approach the development of HFMEA applications in modern RT procedures, comparing recently published research conducted to support proactive programs to identify risks. On the basis of the reviewed literature, the paper suggests HFMEA shortcomings that need to be addressed.
Application of computational fluid dynamics technique in electrodialysis/reverse electrodialysis processes
2022
This Chapter treats the application of CFD technique in ED/RED processes. CFD simulations are able to predict flow and mass transfer in channels filled with spacers or membrane profiles, by providing dimensionless correlations useful for process models. At a larger scale, manifolds of the stack and inlet/ outlet zones of the channel can be simulated. Numerical models can include the computation of the electrical potential, thus characterizing the process performance. Direct numerical simulations can elucidate the complex phenomenology of overlimiting transport and of chaotic electrokinetic flows.
Analisi numerica degli effetti della deformazione di membrane a scambio ionico sulla distribuzione dei fluidi in canali di Elettrodialisi
2019
L’elettrodialisi (ED) è una promettente tecnologia a membrana utilizzata in diversi campi, ad esempio nella dissalazione delle acque e nell’industria alimentare. L’ED usa un potenziale elettrico per indurre una migrazione selettiva di cationi ed anioni da una soluzione elettrolitica ad un’altra, sfruttando membrane a scambio ionico. Membrane anioniche e cationiche sono alternativamente collocate all’interno di una unità ED. A queste sono solitamente interposti spaziatori che prevengono il contatto tra le membrane e delineano i canali in cui scorrono le soluzioni. L’utilizzo di membrane profilate consente di costruire unità prive di tradizionali spaziatori a rete non conduttivi. In genere, l…