A nonlinearity lagging for the solution of nonlinear steady state reaction diffusion problems

This paper concerns with the analysis of the iterative procedure for the solution of a nonlinear reaction diffusion equation at the steady state in a two dimensional bounded domain supplemented by suitable boundary conditions. This procedure, called Lagged Diffusivity Functional Iteration (LDFI)-procedure, computes the solution by "lagging'' the diffusion term. A model problem is considered and a finite difference discretization for that model problem is described.Furthermore, properties of the finite difference operator are proved. Then, sufficient conditions for the convergence of the LDFI-procedure are given. At each stage of the LDFI-procedure a weakly nonlinearalgebraic system has to be solved and the simplified Newton-Arithmetic Mean method is used. This method is particularly well suited for implementation on parallel computers.Numerical studies show the efficiency, for different test functions, of the LDFI-procedure combined with the simplified Newton-Arithmetic Mean method. Better results are obtained when in the reaction diffusion equation also a convection term is present

Lagged diffusivity fixed point iteration for solving steady-state reaction diffusion problems

The paper concerns with the computational algorithms for a steady-state reaction diffusion problem. A lagged diffusivity iterative algorithm is proposed for solving resulting system of quasilinear equations from a finite difference discretization. The convergence of the algorithm is discussed and the numerical results show the efficiency of this algorithm

Riqualificazione del complesso ex Pirelli quale parte del Polo Archivistico Livornese

La presente Tesi di Laurea tratta il progetto di Riqualificazione del complesso ex Pirelli quale parte del Polo Archivistico Livornese, sito a Livorno presso Viale Carducci, antico asse di espansione della città. La Tesi segue le direttive del bando di concorso per la progettazione degli interventi per la riqualificazione del sito, indetto nel 2008 dal Comune di Livorno. L’obiettivo è quello di far rivivere questa porzione di tessuto urbano che, persa l’originaria funzione con la chiusura dello Stabilimento alla fine degli anni ’70 e il trasferimento in zona industriale nel 1982, ha conseguentemente perso la sua identità, e che, non essendo stata trovata un’adeguata soluzione di riqualificazione, ha raggiunto oggi un avanzato stato di degrado. Data la complessità del tema e la vastità dell’area interessata (che oltre allo spazio pubblico da riqualificare strettamente connesso al Parco pubblico Sandro Pertini, comprende i fabbricati industriali dismessi per una superficie coperta che supera i 5.600 mq), il percorso iniziale della Tesi è stato condiviso con la collega Maria Chiara Lopardo, laureata nella precedente sessione di laurea in Ingegneria Edile-Architettura con Tesi dal titolo "Recupero di edificio industriale nell'ambito del progetto di riqualificazione del complesso EX-Pirelli a Livorno". Effettuati questi studi e definite le funzioni, la presente Tesi propone per l’area in questione una soluzione progettuale che ha riguardato specificatamente il recupero funzionale e architettonico del fabbricato in cui realizzare il polo Archivistico-Bibliotecario. Negli ultimi decenni sono stati realizzati veri e propri “centri di scambio culturale” collocati in edifici storici o in aree industriali dismesse, con l’obbiettivo di “rivitalizzare” non solo l’edificio ma l’intera zona coinvolta. Nasce quindi l’esigenza di una distribuzione interna delle funzioni assai differente rispetto agli archivi tradizionali e la necessità di adeguare i vecchi edifici e impianti alle recenti norme. Secondo il criterio della “valorizzazione” espresso nel Codice dei Beni Culturali e del Paesaggio, queste strutture possono essere in grado di offrire occasioni di svago utili alla crescita culturale dell’individuo di qualsiasi età e all’impiego creativo del tempo libero, devono quindi garantire: la buona conservazione della documentazione e al tempo stesso una regolare e confortevole fruizione da parte dei visitatori e degli studiosi, l’accessibilità a tutti ed essere flessibili per accogliere servizi sempre nuovi e diversi. Il progetto in questione, oltre ad adempiere alle funzioni di deposito e conservazione, avrà quindi anche una funzione pedagogica e sociale il cui fine è quello di preservare il passato, come luogo di memoria fortemente legato al contesto locale, ma anche di farsi interprete delle necessità presenti della comunità, come luogo di informazione e socializzazione. Traendo spunto da queste considerazioni, l’intenzione della Tesi è quella di sottolineare come sia fondamentale, già dalle fasi preliminari della progettazione, la concomitante valutazione di svariati aspetti, quali la valutazione dello stato di fatto, le soluzioni tecnologiche da adottare, il rispetto dei requisiti tecnici e ambientali richiesti dalle particolari funzioni, etc…, a dimostrazione della inevitabile interdisciplinarietà del processo edilizio. English text: REDEVELOPMENT OF EX PIRELLI COMPLEX AS PART OF LIVORNO’S ARCHIVES CENTRE This degree thesis treats about the planning of the Redevelopment of ex Pirelli complex as part of Livorno’s Archives Centre, located near Viale Carducci, an old area of urban expansion. This plan have a pedagogical and social function as well as fulfill the functions of storage and preservation of archival material: preserve the past, as a place of memory strongly linked to the local context, and interprets the present needs of the community, as a place of information and socialization. This thesis is also stressed the importance of concomitant evaluation of several aspects, right from the preliminary design stages, demonstrating the inevitable interdisciplinary nature of the building process

On the Lagged Diffusivity Method for the solution of nonlinear finite difference systems

In this paper, we extend the analysis of the Lagged Diffusivity Method for nonlinear, non-steady reaction-convection-diffusion equations. In particular, we describe how the method can be used to solve the systems arising from different discretization schemes, recalling some results on the convergence of the method itself. Moreover, we also analyze the behavior of the method in case of problems presenting boundary layers or blow-up solutions

Application of yttrium coatings on chromium- base alloys by metalliding Final report

Electroplating and vacuum evaporation of yttrium oxide-chromium oxide coating of chromium alloys for nitrogen embrittlement protectio

Numerical studies on semi-implicit and implicit methods for reaction-diffusion equations

In this report Rosenbrock, extended and generalized trapezoidal formulae are considered. Numerical studies on these methods have been developed on a linear and a nonlinear reaction diffusion convection equation

Hestenes method for symmetric indefinite systems in interior-point method

This paper deals with the analysis and the solution of the Karush-Kuhn-Tucker (KKT) system that arises at each iteration of an Interior-Point (IP) method for minimizing a nonlinear function subject to equality and inequality constraints.This system is generally large and sparse and it can be reduced so that the coefficient matrix is still sparse, symmetric and indefinite, with size equal to the number of the primal variables and of the equality constraints. Instead of transforming this reduced system to a quasidefinite form by regularization techniques used in available codes on IP methods, under standard assumptions on the nonlinear problem, the system can be viewed as the optimality Lagrange conditions for a linear equality constrained quadratic programming problem, so that Hestenes multipliers' method can be applied. Numerical experiments on elliptic control problems with boundary and distributed control show the effectiveness of Hestenes scheme as inner solver for IP methods

Soybean oil biodiesel production in Argentina case study

Soybean production is immersed within a productive system that cannot be analyzed on its own. A number of political and market factors, both nationally and internationally, explain the development and growth of soybean production throughout the globe. In the case of Argentina, the evolution of the agricultural system of soybean production has been characterized by continuous technological improvement. This has changed the whole agricultural system and set the base for societies growing demands for environmental and socially responsible goods. An advancement of regulatory context has allowed a better control of the future development of land usage. In Argentina’s case the Law of minimum budget (Law on Conservation of Native Forest) is an example towards that direction. The Argentinean soy industry is one of the most dynamic economic sectors of the country, generating almost 30% of the external currencies income due to exports and representing almost 30% of GDP from the agro-industrial sector. Argentina is the world’s leading exporter in soybean oil, soy meal and soy biodiesel and the third one in soybeans. The future expansion of this industry in the country is heavily dependent on internal and external changes in policies and is thus uncertain. A complete LCA study following EU procedures were performed. Several studies have been carried over in order to clerarly calculate according to international methodologies the GHG emitions of Argentine biodiesel. Since the country has different agroecosystems and distances from the ports can be very different complete research studies were carried over on different regions of the country With respect to GHG emissions (Kg CO2 eq/km), at a global level it could be said that The scenario that showed more GHG emissions was South East of Bs.As. (0,0447 Kg CO2 eq/km). Comparatively and percentage with conventional diesel, its reductions of GHG emissions were of 75,5 %. Recent studies over very precise figures from farm to port on regional plants gave reduction percentages over 70 %.Instituto de Ingeniería RuralFil: Hilbert, Jorge Antonio. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Ingeniería Rural; ArgentinaFil: Galbusera, Sebastián. Ministerio de Ambiente y Desarrollo Sustentable de la Nación. Dirección de Cambio Climático; ArgentinaFil: Galligani, Sofía. Ministerio de Ciencia, Tecnología e Innovación de la Nación. Unidad Gabinete de Asesores; Argentin

Identités plurielles à l'école : catégorisations et diversité des pratiques

Cet article s'attachera à la question de la prise en compte éducative des identités plurielles des enfants venus d'ailleurs et scolarisés à l'école française. Dans un premier temps, il s'agira de clarifier ce que l'on entend par l'expression "identité(s)" en contexte scolaire afin de l'articuler avec les différentes catégorisations utilisées dans les discours officiels pour identifier les enfants étrangers. Partant de l'implication de l'institution scolaire dans la (re)construction des identités sociales des enfants nouvellement arrivés en France, on examinera les paramètres contextuels qui permettent de gérer les identités plurielles et les plurilinguismes. Notre réflexion prendra appui sur les premiers résultats d'une recherche menée sur une structure d'accueil pour les nouveaux arrivants – un CRI (cours de rattrapage intégré) – implantée dans une école primaire publique à sections internationales. Nous verrons ainsi, à travers cet exemple, comment la "culture du contexte" permet d'inscrire la pluralité des identités et le plurilinguisme comme principe éducatif.This article focuses on the way education addresses the issue of the plural identities of children recently arrived in France to be schooled. Firstly, we will clarify what is meant by "identities" in the school context with a view to associating the notion with different categories used in official texts to identify foreign children. Whilst postulating the implication of the school as an institution in the (re)construction of the social identities of newcomers to France, the contextual parameters which influence plural identities and plurilingualism will be examined. We will base our arguments and reasoning on the initial results of a research project concerning a structure designed to welcome newcomers – a CRI (cours de rattrapage intégré), a special class focused on enabling these pupils to catch up and integrate normal classes – in a state primary school with international sections. This example will enable us to show how the "contextual culture" enables the education system to cater for plural identities and plurilingualism as an educational principle

First Evidence of Macrobotanical Remains in the Archaeological Site Familia Primon (Santa Fe, Argentina)

Los macrorrestos vegetales presentan una baja frecuencia de recuperación en los sitios arqueológicos del nordeste de Argentina, debido a que su preservación se ve seriamente afectada —entre otros factores— por las condiciones ambientales predominantes en el área (v. g. humedad, lluvias). En consecuencia, las investigaciones que utilizan este tipo de materiales como proxy son escasas. Este trabajo tiene como objetivo dar a conocer los primeros hallazgos de restos carpológicos en el sitio Familia Primón (Santa Fe, Argentina), pertenecientes a las especies Annona emarginata y Harrisia martinii, y evaluar sus implicancias arqueológicas. Los resultados obtenidos aportan información sobre el potencial aprovechamiento de recursos vegetales en el pasado y complementan los estudios palinológicos realizados en el sitio.Macrobotanical remains have a low recovery frequency in archaeological sites of Northeast Argentina. Their preservation is affected —among other factors— by the environmental conditions in the area, for instance humidity and rainfall. Therefore, research that uses this kind of evidence as a proxy is scarce. This paper aims to show the first carpological remains —which belong to Annona emarginata and Harrisia martinii species— in the archaeological site Familia Primon (Santa Fe, Argentina) to assess its archaeological implications. The results bring information about the potential exploitation of vegetable resources in the past and complement palynological studies in the above-mentioned site.Fil: Sartori, Julieta Isabel. Fundación Arqueológica; Argentina. Universidad Nacional de Lanús; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Balducci, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Arqueológica; ArgentinaFil: Galligani, Paula Elisabet. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Fundación Arqueológica; Argentin