Improved robustness study of a shock ignited target, with DUED code including non-local electron transport and 3D laser ray-tracing

Accurate descriptions of laser power coupling to the plasma and electron energy transport are crucial for designing shock-ignition targets and assessing their robustness (in particular with regard to laser and positioning errors). To this purpose, the 2D DUED laser fusion code has been improved with the inclusion of a 3D laser ray-tracing scheme and a model for non-local electron transport. 2D simulations with the upgraded code are presented; the dependence of the fusion yield vs target displacement is studied. Two different irradiation configurations are considered

Magnetic field generation and diffusion by a laser-produced blast wave propagating in non-homogenous plasma

In this paper we discuss the magnetic field self generation, via the so-called Biermann battery effect, and its diffusion for a blast wave (BW) expanding in a perturbed background medium. A series of simulations verify the bi-linear behavior of the Biermann battery source term both in amplitude and in wavenumber. Such a behavior is valid in the limit of no diffusivity. When diffusivity is also considered, we observe an inverse proportionality with the wavenumber: for large wavenumber perturbation magnetic diffusivity plays a key role. Writing the induction equation in a dimensionless form we discuss how, in terms of magnetic properties, the BW can be subdivided into three main regions: the remnant where the frozen-in-flow approximation holds, the thin shell where the magnetic field is in fact generated but at the same time begins to diffuse, and the shock front where the magnetic field diffuses away. A possible experimental scenario that could induce magnetic fields of about 100 gauss is finally investigated. Simulations have been performed with the code DUED

L'Econometria per le indagini territoriali: appunti metodologici e un'applicazione alla Sardegna

Il recente interesse scientifico per la new economic geography ha favorito il sorgere e il consolidarsi di un filone di ricerca di economia applicata che mira alla formalizzazione e misurazione delle relazioni spaziali fra fenomeni economici. Questa attività di ricerca, dapprima relegata in una nicchia accademica, oggi trova progressivamente applicazione nei corsi universitari, segno di una disciplina che suscita interesse per l’approccio innovativo all’indagine delle dinamiche sociali ed economiche. L’econometria spaziale nasce come branca dell’econometria tradizionale con la finalità di affrontare le problematiche connesse all’impiego di dati georeferenziati, cioè collegati ad entità geografiche. Fra i vari temi assumono rilevanza particolare l’interdipendenza (o autocorrelazione) e l’eterogeneità (o eteroschedasticità) spaziale. Per essi, troppo spesso, gli elementi forniti dalla econometria tradizionale appaiono insufficienti. Questo lavoro si propone di rendere esplicite le peculiarità proprie delle tecniche dell’econometria spaziale insieme ad alcune istruzioni d’uso per le loro applicazioni concrete

Il Knowledge management nel Lean PLM

L’obiettivo del presente lavoro di tesi è l’implementazione di un modulo del software ARAS Innovator che permetta di supportare le metodologie note sotto il nome di Lean Product Development, che permettono di applicare le metodologie Lean, introdotte da Toyota, alla produzione manifatturiera. Il software ARAS non mette a disposizione di un modulo specifico per la gestione della progettazione e sviluppo in maniera “lean”; è stato quindi creato un nuovo modulo sfruttando sia le funzionalità già presenti nel software, sia creandone delle nuove per riuscire a raggiungere gli obiettivi della tesi. Attraverso questo modulo sarà quindi possibile per un’azienda, creare e gestire un nuovo progetto, definire dei rischi associato a esso e gestirli attraverso i così detti “Learning cycle event”. A ognuno di essi sarà associato uno specifico documento A3, sviluppato da zero all’interno del programma, rendendo possibile analizzare, gestire e confrontare le performance delle diverse soluzioni studiate per riuscire a mitigare ognuno dei rischi. Lo studio partirà analizzando la metodologia di progettazione nota sotto il nome di set-based concurrent engineering, analizzando le migliorie rispetto alle precedenti tecniche di progettazione industriale e come queste possono essere applicate; si studieranno e analizzeranno in dettaglio due diversi strumenti per la gestione dei progetti: gli A3 e le trade-off curves. In seguito si farà una rapida introduzione ai software PLM, per poi passare all’analisi del funzionamento del PLM ARAS Innovator. Tutte le tematiche analizzate nel presente lavoro di tesi si basano sugli studi effettuati da Ronald Mascitelli, e riportati sul libro “Mastering lean product development: A practical event-driven process for maximizing speed, profits and quality”

Sustainable tourism development and climate change: a supply-side perspective

This paper presents and discusses findings of research carried out on a sample of 141 tourism stakeholders with two tourism destinations located in Sardinia, Italy. Specifically, it investigates: (1) the priorities that respondents consider essential to attain sustainability and competitiveness for their business and the destination as a whole, (2) the main barriers to tourism sustainability and (3) their attitude towards climate change and its influence on tourism. Our contribution to the literature, along with managerial implications, is discussed and suggestions for future research are given

Design of absolute equation of state measurements in optically thick materials by laser-driven shock waves

Abstract Some aspects of the design of a target for the absolute measurement of Equation-of-State data at pressure of tens of Mbar, in optically thick materials are discussed. In the proposed experiment, a shock wave is generated in a laser-irradiated sample, and the shock velocity and the material velocity behind the shock are simultaneously measured by the optical and X-ray diagnostics. Accurate measurements require the generation of a steady, planar shock, and the detection of the motion of a shocked fluid interface by transverse radiography. One- and two-dimensional numerical fluid simulations have been performed to optimize beam and target design, in order to fulfil such requirements

Cross-Disciplinary Approaches to the Regeneration of Minor Historical Centers: The Case of Mogoro in Sardinia

In Italy, the regeneration of historic centers is a relevant issue in the theoretical debate and practice of urban planning, a discourse which usually adopts strictly constraining approaches and tools directed almost exclusively at the preservation of the traditional characters of historic build- ings, neglecting social and economic processes. In particular, the redevelopment of minor historic centers becomes a priority action for the revitalisation of marginal territories affected by the phe- nomena of depopulation and weakening of the socio-economic structure. The paper focuses on the regional context of Sardinia to investigate methods and criteria for the drafting of planning tools for the redevelopment of minor historic centers, enabling the definition and implementation of strate- gies in accordance with the objectives and guidelines of the Regional Landscape Plan. With a case study methodology applied to the historic center of Mogoro, the research discusses an innovative and interdisciplinary approach to the definition of flexible regulations to manage the urban regen- eration process

PhaseX: an X-ray phase-contrast imaging simulation code for matter under extreme conditions

We present PhaseX, a simulation code for X-ray phase-contrast imaging (XPCI), specially dedicated to the study of matter under extreme conditions (of pressure and density). Indeed, XPCI can greatly benefit the diagnosis of such states of matter. This is due to the noticeable contrast enhancement obtained thanks to the exploitation of both attenuation and phase-shift of the electromagnetic waves crossing the sample to be diagnosed. PhaseX generates synthetic images with and without phase contrast. Thanks to its modular design PhaseX can adapt to any imaging set-up and accept as inputs objects generated by hydrodynamic or particle-in-cell codes. We illustrate Phase-X capabilities by showing a few examples concerning laser-driven implosions and laser-driven shock waves

Sustainable Tourism Development and Climate Change: A Supply-Side Perspective

This paper presents and discusses findings of research carried out on a sample of 141 tourism stakeholders with two tourism destinations located in Sardinia, Italy. Specifically, it investigates: (1) the priorities that respondents consider essential to attain sustainability and competitiveness for their business and the destination as a whole, (2) the main barriers to tourism sustainability and (3) their attitude towards climate change and its influence on tourism. Our contribution to the literature, along with managerial implications, is discussed and suggestions for future research are given

Sustainable Tourism Development and Climate Change: A Supply-Side Perspective

This paper presents and discusses findings of research carried out on a sample of 141 tourism stakeholders with two tourism destinations located in Sardinia, Italy. Specifically, it investigates: (1) the priorities that respondents consider essential to attain sustainability and competitiveness for their business and the destination as a whole, (2) the main barriers to tourism sustainability and (3) their attitude towards climate change and its influence on tourism. Our contribution to the literature, along with managerial implications, is discussed and suggestions for future research are given