Constructing Dirac linear fermions in terms of non-linear Heisenberg spinors

We show that the massive (or massless) neutrinos can be described as special states of Heisenberg nonlinear spinors. As a by-product of this decomposition a particularly attractive consequence appears: the possibility of relating the existence of only three species of mass-less neutrinos to such internal non-linear structure. At the same time it allows the possibility that neutrino oscillation can occurs even for massless neutrinos

Contributi per il patrimonio rupestre: da una piccola esperienza di rilievo alcune questioni di metodo.Research for rupestrian heritage: from a little survey experience to methodological issues

Il presente contributo ha l'obiettivo di analizzare alcune tematiche relative agli antichi rioni Sassi di Matera, partendo dalla conoscenza e dal rilievo di un manufatto tipico. L'agglomerato urbano dei Sassi, si configura come continuazione naturale del paesaggio rupestre circostante, riproposto come insediamento antropico originale, nella spontaneità delle sue forme e delle sue architetture. L'esperienza di ricerca, operativamente condotta, intende illustrare gli esiti ottenuti nel campo del rilievo e commentare alcune modalità di natura speditiva che sono state adottate per l'individuazione degli aspetti geometrici (forma e misura) delle consistenze, la conoscenza storico-evolutiva del manufatto e le relative forme di rappresentazione utili a restituire la specificità del bene architettonico. È interessante proporre una valutazione critica dei risultati conseguiti, che si pongono come esempio di lavoro per un'indagine di rilievo basato su un investimento limitato di risorse e l'uso di strumentazioni di base. Parte del lavoro si concentra sull'identificazione delle fasi che hanno interessato il progressivo e tipico sviluppo della cellula originaria e del successivo complesso costruito con l'intento di ripercorrere il mutamento da "grotta rupestre" a "lamione" dei Sassi. L'esplorazione di un singolo edificio, collocato all'interno di un sistema urbano complesso, lo estrae temporaneamente dal contesto circostante, ne permette una lettura diretta, ma deve mantenere vive le relazioni che lo legano ai valori dell'ambito di cui fa parte. Il lavoro si inserisce, pertanto, nel campo di indagine della conoscenza di ambienti e manufatti rupestri, con l'intento di mostrare la validità della metodologia adoperata e la sua applicazione ad un caso studio reale. The current research aims at investigating some topics related to the ancient neighborhoods of Matera called Sassi, starting from the knowledge and the survey of a typical building. The urban area of Sassi represents the natural extension of the surrounding rupestrian landscape, proposed as original human settlement, in the spontaneity of its shapes and its architecture. The research shows the results in the field of survey and proposes a fast method to indentify geometrical aspects (shape and measure) of building consistence, but at the same time, the historical evolution and the different visual representations of the building, in order to represent the specific nature of the architectural. It is interesting to propose a critical evaluation of results, that represents a valid working experience, based on limited resources and basic tolls. Part of the work focuses the attention on the identification of significant milestones that have concerned the progressive development of the original cell and the future building, with the aim of retracing the transformation from "rupestrian cave" to typical "lamione" of Sassi. The exploration of a single building, located in a complex urban system, temporarily removes it from the surrounding context and allows us a direct analysis of the building, but it must keep alive the relationships with the context which it belongs. Therefore, the work fits to the field of rupestrian environments, with the aim of showing the validity of methodology and its application to a real case stud

Geometrical aspects of light propagation in nonlinear electrodynamics

We analyze the propagation of light in the context of nonlinear electrodynamics, as it occurs in modified QED vacua. We show that the corresponding characteristic equation can be described in terms of a modification of the effective geometry of the underlying spacetime structure. We present the general form for this effective geometry and exhibit some new consequences that result from such approach.Comment: LaTex, 11 pages, accepted for publication in Phys. Rev.

La Geometria come filo di Arianna: note di approfondimento sul rapporto ideazione-costruzione della più grande cupola di forma ovata del mondo

La cupola del Santuario di Vicoforte in Piemonte costituisce un'opera di particolare complessità costruttiva sia per le sue dimensioni sia per la sua forma: è infatti la più grande cupola ovata in muratura nel mondo. Questo studio riguarda la genesi geometrica della costruzione delle cupola, ed evidenzia che la cupola costruita è, da un punto di vista dei parametri geometrici, alquanto diversa da quella disegnata nei progetti. La ricerca è focalizzata sull'analisi geometrica delle sezioni verticali della cupola, al fine indagare il profilo delle centine usate nella costruzione. I risultati possono consentire una più attillata definizione dei modelli di simulazione del comportamento strutturale e sismico che sono necessari per la conservazione dell'integrità del manufatto. The dome of the Sanctuary of Vicoforte, the largest oval masonry dome in the world, is an exceptional expression of building technique for its shape and dimension. This study wants to add information about the geometrical conception of the dome using the modern modeling possibilities based on recent laser scanner survey. In particular it integrates the analysis of the archival drawings and the 3D survey of the dome in order to investigate the geometrical shape of the temporary centrings used in the dome construction. Improving the knowledge about the tridimensional shape and the construction techniques of such dome is of crucial importance at the moment, because the Sanctuary is the subject of a structural monitoring and research campaign due to the important settlements and cracking fenomena that affect the buildin

3D Models for the restoration project: some issues and case study

Il contributo mira ad esplorare la modellazione 3D e le questioni inerenti a contenuti e scale di rappresentazione, sulla base di un'esperienza applicativa. L'obiettivo di questa ricerca è stato quello di testare la flessibilità di strumenti di modellazione adatti per essere usati a supporto di metodi di intervento conservativi e di restauro. Nel corso della sperimentazione si sono dovuti affrontare alcuni problemi di metodo che appaiono centrali per gli sviluppi futuri, e che hanno dettato alcune considerazioni sul grado di influenza delle tecnologie impiegate; i risultati comprovano quanto l'esperienza di lavoro (rilievo, analisi e restituzione) anche di tipo operativo sia significativa nell'orientare le più opportune metodologie di indagine e lavoro da scegliere in relazione alla al caso specifico

CAD, BIM, GIS and other tricks of the computer science in the education of the Building Engineer

Revisione internazionale- relazione a invito- chair sessione S8T The paper aims to develop some thoughts on the upgrade implemented in the disciplines of drawing from the latest forms of digital representation, commenting on the experiences under way in some university courses included in the learning curriculum provided to engineering students with regard to the course of study in Ingegneria Edile (Building Engineering, also known as Architectural or Construction Engineering) at the Politecnico di Torino. It’s a matter of reasoning on what and how to suggest knowledge and practises in the experience of teaching that result as an improvement of skills and abilities appropriate for future commitments required by the job world. Method: Methodological reasons, subject contents and experiences positively carried out during the activities of the course of Representation Techniques and Data Management (in the post graduate “Laurea Magistrale”) are treated, focusing on all the resources needed to conduct profitable operations training and first clarifying the specific skills and experience required for the teaching staff, essential qualities to ensure good results: all the activities organized to achieve the training objectives are based on the belief that early training is needed to trigger virtuous review processes for engineering practice and that opportunities to practice through simulations in the academic curriculum for future engineers can produce effects of greater permanence and enable an enhancement of learning outcomes. Result: The analysis, which is addressed primarily to illustrate the result of some of the outcomes of exercise activities leaded by students, brings attention to a solicitation that seems to be constraining and that concerns the system of relations required between operators of the design and construction process, which are requested to enter into shared aims while operating in the specificity of the various technical fields; in this sense, the tricks of the CAD, which is at the service of a geometric knowledge, measured and fulfilled by its attributes, the attention demanded by BIM, which builds a widespread and open network of relationship, the cunnings of the GIS, which has to gather dynamic information and alternative choices, appear to address areas of operational testing following a single purpose directed towards a better characterization of the process of conceptual development and a more advantageous control of the working method. Discussion & Conclusion: So, with the design and over the usual representations, we speak of computer tricks to say that to be understood as the necessary infrastructure to solicit and investigate the reasons of doing and how to solve the complexity of operating on the field, upon which students must impractical themselves to identify qualities and limits, whether they are exploring the reasons of the survey or the reasons bound with the design; certainly a renewal for the most usual ways of designing useful to produce different levels of knowledge and a new shared place for the exchange and discussion of the hypotheses, with what results

Quantum vacuum fluctuations and dark energy

It is shown that the curvature of space-time induced by vacuum fluctuations of quantum fields should be proportional to the square of Newton's constant $G$. This offers a possible explanation for the success of the approximation $G m^6 c^2 h^{-4}$ for the dark energy density, with $m$ being a typical mass of elementary particles.Comment: Changed conten

Acoustic analogues of black hole singularities

We search for acoustic analogues of a spherical symmetric black hole with a pointlike source. We show that the gravitational system has a dynamical counterpart in the constrained, steady motion of a fluid with a planar source. The equations governing the dynamics of the gravitational system can be exactly mapped in those governing the motion of the fluid. The different meaning that singularities and sources have in fluid dynamics and in general relativity is also discussed. Whereas in the latter a pointlike source is always associated with a (curvature) singularity in the former the presence of sources does not necessarily imply divergences of the fields.Comment: 9 pages, no figure

Which drawing to deliver more information?

The paper explores the potential of methods and languages designed to facilitate the communication of appropriate information content for the different levels of detail required in the creation of an architectural design, levels with different purposes, but nevertheless co-ordinated. Within this thesis, the many different facets of drawing and the language of graphics are confirmed as agents of intellectual mediation, as a support for expression and also as dynamic cultural and evolving factors. In order to reply to the new demands of performance, due to the increasing fragmentation of responsibility for design, some adjustments in the workflow are needed, essential to support renewed practices; in fact, supporting this dynamic, the representation seems to have recovered a role of increased visibility and importance, regaining an effective recognition through a reconfirmation that remarks the delicate function of communication, interpretation and criticism. The added value of the BIM methodologies (Building Information Modeling), is not limited by the ability to handle graphical representations at different scales with a single 3D model, but it answers to some requests connected by the data complexity inherent with the design and construction, actively supporting the engineering process: this means to relate actors or the building process to each other in a new way, reforming the assets and the processing modes, requiring explicit coordination for activities and procedures. At this regard, we analyze new operational workflow through a brief description of some designs carried out through the collaboration between DISEG (Department of Structural, Geotechnical and Building Engineering) and the Building Service of the Politecnico di Torino, speaking about drawings and representations

Cosmological Effects of Nonlinear Electrodynamics

It will be shown that a given realization of nonlinear electrodynamics, used as source of Einstein's equations, generates a cosmological model with interesting features, namely a phase of current cosmic acceleration, and the absence of an initial singularity, thus pointing to a way to solve two important problems in cosmology