136 research outputs found
Progetto di due isolati a funzioni miste a Verona
No full textProgetto di due isolati a funzioni miste a Verona sud, Verona, 2007.
Il progetto per due isolati destinati a funzioni miste a Verona rappresenta una opportunità di verifica necessaria per le ricerche teoriche e progettuali condotte sul tema del progetto urbano e sul tema della riqualificazione urbana.
Rispetto al quadro generale il progetto sviluppa e si articola attraverso due ambiti progettuali: uno urbano e uno edilizio. Per l’ambito urbano assume un ruolo primario la strada che, da semplice infrastruttura viabilistica, torna a essere uno spazio collettivo e urbano a tutti gli effetti. Il fronte stradale, con i suoi edifici allineati, rappresenta uno dei temi importanti dell’architettura della città perché in grado di connotare e indirizzare i legami tra l’aspetto tipologico delle abitazioni, lo spazio urbano in generale e la dimensione civile dell’architettura. Dal punto di vista tipologico il progetto propone un tipo edilizio abitativo in cui la residenza si fonde inestricabilmente con alcuni servizi a essa legati, ricreativi, commerciali, e lavorativi (uffici) creando una unità insediativa urbana complessa, alternativa alla pratica urbanistica tradizionale degli standard e dello zoning, cercando di restituire alla città quel sovrapporsi di funzioni e di modi di vita tipiche dei nuclei urbani prima delle grandi espansioni periferiche del secondo dopoguerra
A comparison between different approaches for the numerical treatment of bottom discontinuities in a DG perspective
No full textThe use of Discontinuous Galerkin (DG) numerical schemes for the Shallow Water Equations (SWE) integration is greatly increased in the last decade. The efforts of many researchers were initially devoted to conceive techniques for the exact preservation of the motionless state over non-flat bottom. Recently, such efforts are mainly oriented to the proper treatment of the bottom discontinuities and to the exact preservation of the moving-water steady flows.
In this work, in the unified context consisting of third-order accurate DG-SWE schemes, a comparison between five numerical treatments of the bottom discontinuities is presented.
We consider three widespread approaches that perform well if the motionless state has to be preserved. First, a simple technique, which consists in a proper initialization of the bed elevation that imposes the continuity of the bottom profile is taken into account [Kesserwani and Liang, INT J NUMER METH ENG, 86, 47-69, 2011]. Then, we consider the hydrostatic reconstruction method [Audusse et al., SIAM J SCI COMPUT, 25, 2050-2065, 2004] and a path-conservative scheme based on a linear integration path [Parés, SIAM J NUMER ANAL, 44, 300-321, 2006].
We also consider two further approaches (both based on mechanical principles) which are promising for the preservation of a moving-water steady state. A model is obtained modifying the hydrostatic reconstruction as suggested in [Caleffi and Valiani, ASCE JEM, 135(7), 684-696, 2009]. This method is characterized by a correction of the numerical flux based on the local conservation of the total energy. The last model is obtained improving the path-conservative scheme using a non-linear path.
Several test cases are used to verify the accuracy, the well-balancing, the behavior in simulating a quiescent flow and the resolution in simulating unsteady flows of the models. A specific test case is also introduced to highlight the difference between the five schemes when a steady moving flow interacts with a bottom step
Maxillary tooth splinting in periodontally compromised patients using fiber-reinforced composite: the Targis-Vectris method
No full textAIM: To show the Targis-Vectris retention technique, illustrating its features and clinical applications in periodontally compromised patients. METHODS: The Targis-Vectris technique is constituted by an esthetic external layer (Targis) combined with and supported by a metal-free structure (Vectris). An adult female with a full Class II malocclusion and compromised periodontal condition with significant bone loss on the maxillary central incisor was treated. Before debonding, a fiber-reinforced splint was placed on the palatal surface of the maxillary anterior teeth, using the Targis-Vectris method, to permit long-term stability. The final result remained stable at 5 years posttreatment. RESULTS: The correction of the Class II malocclusion took 24 months. The Targis-Vectris method ensured maintenance of tooth position and periodontal condition. CONCLUSION: The Targis-Vectris technique represents a useful procedure for splinting maxillary teeth in selected periodontally compromised patients. The 5-year posttreatment follow-up visit showed no relapse. Correct occlusal relationships are necessary to reduce the risk of breakage
Modeling blood flow in viscoelastic vessels: the 1D augmented fluid–structure interaction system
No full textNowadays mathematical models and numerical simulations are widely used in the field of hemodynamics, representing a valuable resource to better understand physiological and pathological processes in different medical sectors. The theory behind blood flow modeling is closely related to the study of incompressible flow through compliant thin-walled tubes, starting from the incompressible Navier–Stokes equations. Furthermore, the mechanical interaction between blood flow and vessels wall must be properly described by the model. Recent works showed the benefits of characterizing the rheology of the vessel wall through a viscoelastic law. Taking into account the viscous contribution of the wall material and not simply the elastic one leads to a more realistic representation of the vessel behavior, which manifests not only an instantaneous elastic strain but also a viscous damping effect on pulse pressure waves, coupled to energy losses. In this context, the aim of this work is to propose an easily extensible one-dimensional mathematical model able to accurately capture fluid–structure interactions. The originality of the model lies in the introduction of a viscoelastic tube law in PDE form, valid for both arterial and venous networks, leading to an augmented fluid–structure interaction system. In contrast to well established mathematical models, the proposed one is natively hyperbolic. The model is solved with an efficient and robust second-order numerical scheme; the time integration is based on an Implicit–Explicit Runge–Kutta scheme conceived for applications to hyperbolic systems with stiff relaxation terms. The validation of the proposed model is performed on several different test cases. Results obtained in Riemann problems, adopting a simple elastic tube law for the characterization of the vessel wall, are compared with available exact solutions. To validate the contribution given by the viscoelastic term, the Method of Manufactured Solutions has been applied. Specific tests have been designed to verify the well-balancing with respect to fluid-at-rest condition and the accuracy-preserving property of the scheme. Finally, a specific test case with an inlet pulse pressure wave has been designed to assess the effects of viscoelasticity with respect to a simple elastic behavior of the vessel wall. The complete code, written in MATLAB (MathWorks Inc.) language, with the implemented test cases, is made available in Mendeley Data repository
Alcuni risultati su moti assialsimmetrici a superficie libera
No full textSi analizza il moto a superficie libera a simmetria assiale, alimentato da un getto cilindrico perpendicolare ad una piastra, oppure, inversamente, alimentato da un flusso radiale centripeto con il recapito consistente in un foro centrale nel quale stramazza, a vena libera, la portata immessa. Facendo riferimento al caso ideale e permanente, caratterizzato da un unico valore del carico totale, si ricavano analiticamente (ed esplicitamente) la soluzione di corrente lenta e quella di corrente veloce su fondo orizzontale, mostrando come una terza soluzione, caratterizzata da profondità ovunque negativa, sia priva di significato fisico. Si ricavano poi le soluzioni di corrente lenta e di corrente veloce su fondo piatto con resistenze, nel caso in cui i termini inerziali siano comunque dominanti rispetto ai termini di attrito. Infine, vengono presentate le soluzioni di corrente lenta e veloce su fondo a quota variabile, nell’ipotesi di assenza di resistenze. Tornando alla trattazione del caso fondamentale (fondo piatto ed assenza di dissipazioni), si introduce la possibilità che si verifichi un risalto idraulico diretto, imposto da appropriate condizioni al contorno. Si ricavano analiticamente la posizione del risalto e le profondità coniugate, mostrando come questi risultati siano funzione, nel caso semplice in cui il risalto sia considerato uno shock inviscido di lunghezza nulla, di un solo numero puro, segnatamente il rapporto tra l’energia specifica a valle ed a monte del risalto stesso
Quantum internet: From communication to distributed computing!: Invited paper
No full textIn this invited paper, the authors discuss the exponential computing speed-up achievable by interconnecting quantum computers through a quantum internet. They also identify key future research challenges and open problems for quantum internet design and deployment
Giovanna Caleffi e la memoria di Camillo Berneri
No full textLa relazione si propone l’obiettivo di spostare l’attenzione dalla figura pubblica di Camillo Berneri al suo ambiente familiare, prestando particolare attenzione al lutto e alla memoria lasciati dal suo assassinio. Si concentrerà, così facendo, sulla figura della moglie, Giovanna Caleffi, che a partire dal maggio-giugno 1937 raccolse il testimone dell’impegno politico del marito. La questione storiografica che si solleva è quella dei rapporti tra sfera pubblica e sfera privata, con la consapevolezza, sempre più presente nella recente letteratura sull’età contemporanea, soprattutto tra i giovani ricercatori, di come la storiografia spesso non sia riuscita a superare la dicotomia tra una prospettiva quasi esclusivamente politica e istituzionale, e un’attenzione privilegiata nei confronti degli individui e delle loro soggettività
Modellazione del flusso sanguigno in reti di vasi viscoelastici
No full textSi descrive la modellazione delle giunzioni tra vasi sanguigni viscoelastici e delle condizioni al contorno. Il confronto di riferimento avviene tra un vaso sanguigno con giunzione e il corrispondente caso di vaso continuo. La trattazione è applicabile sia ad arterie che a vene. Si presenta la simulazione di una rete circolatoria arteriosa e si evidenzia il cappio di isteresi tipico del comportamento viscoelastico
Non-HFE Hepatic Iron Overload.
No full textNumerous clinical entities have now been identified to cause pathologic iron accumulation in the liver. Some are well described and have a verified hereditary basis; in others the genetic basis is still speculative, while in several cases nongenetic iron-loading factors are apparent. The non-HFE hemochromatosis syndromes identifies a subgroup of hereditary iron loading disorders that share with classic HFE-hemochromatosis, the autosomal recessive trait, the pathogenic basis (i.e., lack of hepcidin synthesis or activity), and key clinical features. Yet, they are caused by pathogenic mutations in other genes, such as transferrin receptor 2 (TFR2), hepcidin (HAMP), hemojuvelin (HJV), and ferroportin (FPN), and, unlike HFE-hemochromatosis, are not restricted to Caucasians. Ferroportin disease, the most common non-HFE hereditary iron-loading disorder, is caused by a loss of iron export function of FPN resulting in early and preferential iron accumulation in Kupffer cells and macrophages with high ferritin levels and low-to-normal transferrin saturation. This autosomal dominant disorder has milder expressivity than hemochromatosis. Other much rarer genetic disorders are associated with hepatic iron load, but the clinical picture is usually dominated by symptoms and signs due to failure of other organs (e. g., anemia in atransferrinemia or neurologic defects in aceruloplasminemia). Finally, in the context of various necro-inflammatory or disease processes (i.e., chronic viral or metabolic liver diseases), regional or local iron accumulation may occur that aggravates the clinical course of the underlying disease or limits efficacy of therapy
Penetranting trauma to the scrotum and corpora cavernosa caused by gunshot: clinical case.
No full textThe authors describe a case of gunshot wound of the male genitalia by two
low-velocity bullets. The first bullet caused a lesion of the right testicle and
came out of the right hemiscrotum; the second one had penetrated the left gluteal
region with no exit wound. The penile ultrasound confirmed the presence of the
bullet at the root of the right corpus cavernosum. The patient underwent
exploratory surgery, drainage of the voluminous bilateral scrotal hematoma, and
suture of a laceration of the right-testicle cranial portion. Due to the absence
of active bleeding, voluminous hematoma and serious injuries in the corpus
cavernosum, no surgical removal of the bullet in the right corpus cavernosum was
required. The patient regained a normal sexual function 1 month after the
operation
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