1,420 research outputs found
The Genoese Citizenship of Carlo I Tocco of December 2, 1389 (II)
The Genoese citizenship, granted to Carlo I Tocco and his regent mother Magdalene by the authorities of the Republic of Genova (December 2, 1389) is a document the existence of which is widely accepted in the scholarly circles despite the fact that the details of its content have still remained largely unknown. Attempting to contribute to a better understanding of the circumstances under which the grant was issued, the first part of this paper brings the transcription of the entire document as well as an analysis of its political and legal context. The paper's second part deals with the document's paleographic, diplomatic, and sigillographic features, as well as with its
prosopographic and topographic details
Lattice Boltzmann methods for direct numerical simulation of turbulent fluid flows
We study the use of lattice Boltzmann (LB) methods for simulation of turbulent fluid flows motivated by their high computational throughput and amenability to highly parallel platforms such as graphics processing units (GPUs). Several algorithmic improvements are unearthed including work on non-unit Courant numbers, the force operator, use of alternative topologies based on face and body centered cubic lattices and a new formulation using a generalized eigendecomposition that allows a new freedom in tuning the eigenvectors of the linearised collision operator. Applications include a variable bulk viscosity and the use of a stretched grid, our implementation of which reduces errors present in previous efforts. We present details for numerous lattices including all required matrices, their moments the procedures and programs used to generate these and perform linear stability analysis. Small Mach number flows where density variations are negligible except in the buoyancy force term allow the use of a highly accurate finite volume solver to simulate the evolution of the buoyancy field which is coupled to the LB simulation as an external force. We use a multidimensional flux limited third order flux integral based advection scheme. The simplified algorithm we have devised is easier to implement, has higher performance and does not sacrifice any accuracy compared to the leading alternative. Our algorithm is particularly suited to an outflow based implementation which furthers the stated benefits. We present numerical experiments confirming the third order accuracy of our scheme when applied to multidimensional advection. The coupled solver is implemented in a new code that runs in parallel across multiple machines using GPUs. Our code achieves high computational throughput and accuracy and is used to simulate a range of turbulent flows. Details regarding turbulent channel flow and sheared convective boundary layer simulations are presented including some new insight into the scaling properties of the latter flow
Familiares, Egregii and Homines Despoti Nonnulli: The Retinue on the Hungarian Estates of Despot George Branković and its Social Capacity (1427-1456)
Las propiedades que los gobernantes serbios tardomedievales tenían en el reino de Hungría no son desconocidas para las historiografías nacionales modernas de Europa Central. Estas propiedades se encontraban principalmente en el sur, este y noreste de ese país y fueron inicialmente concedidas por el rey húngaro (y soberano del Sacro Imperio Romano Germánico) Segismundo de Luxemburgo. Este artículo explora las capacidades sociales del entorno “cosmopolita” del déspota serbio George Branković en sus dominios en Hungría (1427-1456) y considera cómo tales capacidades impulsaron el avance social de estos hombres pero también la interacción del déspota (escasa integración) con sus entornos húngaros, haciendo particular hincapié en sus relaciones con la corte regia. En este grupo híbrido “cosmopolita” y socialmente diversificado, se advierte cómo sus avances pudieron estar anclados en sus redes familiares, el conocimiento personal y sus habilidades o servicio militar y cortesano. No obstante, su característica más significativa era la lealtad extraordinaria, que todos los hombres y delegados del déspota –independientemente de su origen social, étnico o religioso– mostraron hacia su señor feudal. Por medio de ese recurso confirmaron sus patrimonios, así como lograron avances posteriores en su estatus, modificando la relación cercana con el déspota y provocando el cambio de una nobleza antiguamente marginalizada desde el punto de vista territorial hacia una nueva nobleza feudal.
Las propiedadesque los gobernantes serbios tardomedievales tenían en el reino de Hungría no son desconocidas para las historiografías nacionales modernas de Europa Central. Estas propiedades se encontraban principalmente en el sur, este y noreste de ese país y fueron inicialmente concedidas por el rey húngaro (y soberano del Sacro imperio Romano Germánico) Segismundo de Luxemburgo. este artículo explora las capacidades sociales del entorno “cosmopolita” del déspota serbio George Branković en sus dominios en Hungría (1427-1456) y considera cómo tales capacida-des impulsaron el avance social de estos hombres pero también la interacción del dés-pota (escasa integración) con sus entornos húngaros, haciendo particular hincapié en sus relaciones con la corte regia. en este grupo híbrido “cosmopolita” y socialmente diversificado, se advierte cómo sus avances pudieron estar anclados en sus redes fa-miliares, el conocimiento personal y sus habilidades o servicio militar y cortesano. No obstante, su característica más significativa era la lealtad extraordinaria, que todos los hombres y delegados del déspota –independientemente de su origen social, étnico o religioso– mostraron hacia su señor feudal. Por medio de ese recurso confirmaron sus patrimonios, así como lograron avances posteriores en su estatus, modificando la relación cercana con el déspota y provocando el cambio de una nobleza antiguamente marginalizada desde el punto de vista territorial hacia una nueva nobleza feudal.
The estates which late medieval Serbian rulers held in the Kingdom of Hungary are not unknown to the modern national historiographies of Central Europe. These estates were cored in southern, eastern and north-eastern Hungary, initially granted by Hungarian King (and Holy Roman emperor) Sigismund of Luxembourg. The paper explores the social capacities of the “cosmopolitan” entourage of Serbian Despot George Branković on his domains in Hungary (1427-1456) and seeks an answer to how these capacities operated in prompting these men’s social advancement but also Despot’s interaction (hardly integration) with his surroundings in Hungary, with a particular focus on his relations with the royal court. In this hybrid “cosmopolitan” and socially diversified group, one can notice as their advancement may have been grafted upon their familial networks, personal knowledge and skills or military and courtly service, but its most significant feature was an extraordinary loyalty which all Despot’s men and proxies –regardless of their social, ethnic of religious background– showed to their feudal lord. it is through this concept that they had their personal assets confirmed, as well as their further status advancements, close relationship with the Despot and change from an ‘olden’ territorial marginalised into the new feudal nobility
PHYSICS-BASED MODELING FRAMEWORK INCORPORATING MICROSTRUCTURAL EVOLUTION FOR PREDICTING DEFORMATION AND RECRYSTALLIZATION OF METALLIC MATERIALS
Large number of metallic parts is produced from the raw materials by a set of mechanical shaping and heating operations. Considering the need for metallic components in the modern industry, the field of thermo-mechanical processing of metallic materials is of immense importance. Even modest improvements of the existing thermo-mechanical processes could potentially result in great savings of time, recourses and energy. Finite element modeling of the forming and heating operations introduced in the past decades has allowed for the optimization of the thermo-mechanical processes and has thus resulted in significant advancements. However, due to the limitations of the presently used constitutive models, certain aspects of the process and effects of the process parameters on the component properties cannot be simulated accurately. Work presented in this dissertation is a contribution to the development of a physics-based crystal plasticity model capable of accurately simulating both the mechanical shaping and heating portions of the process and their effect on the microstructure of the component. The well-established visco-plastic self-consistent polycrystal plasticity (VPSC) model is advanced in several aspects in an effort to develop a coupled deformation-recrystallization model. First, different numerical implementation of the VPSC constitutive model into the finite element framework is developed. In addition, two methods for the accurate representation of the material rate sensitivity within the finite element framework are proposed. The proposed models are verified on Taylor impact tests of Zr and Ta cylinders. Next, an algorithm for statistical description of intragranular fluctuations of crystallographic orientation is developed. The effects of the fluctuations of crystallographic orientation within the grains on the fluctuations of stress and rotation rates are considered as well. The developed model is applied to compression and plane strain compression of fcc material and verified by direct comparison with experimental measurements and full-field predictions. Finally, a physics-based recrystallization model coupled with the developed VPSC model capable of predicting intragranular crystallographic orientation fluctuations is proposed. The coupled deformation-recrystallization model is applied to the recrystallization of fcc and bcc materials and reasonable agreement is observed. Combination of different models proposed in this dissertation allows for the simulation of both shaping and heating portions of the thermo-mechanical process
STRAIN PATH SENSITIVE POLYCRYSTAL PLASTICITY CONSTITUTIVE MODELS WITHIN FINITE ELEMENTS FOR METAL FORMING SIMULATIONS
An optimal sheet metal forming process shapes a metal part to the accurate geometry, while avoiding instabilities causing localization of deformation and fracture. Understanding the underlying mechanisms responsible for deformation localization and deviation of final part geometry from the desired geometry facilitates the search for the optimal sheet metal forming process. Accurate modeling of forming processes allows prediction of the formed part shape and can provide insight into the material behavior by interpretation of experimental measurements and prediction of variables not accessible to experimental characterization. In this work, a micromechanical material model is coupled with finite elements to create a multi-scale model of a metal forming process. In addition, extensions to the micromechanical material model have been implemented to accurately describe the material behavior during complex deformation paths observed during forming processes. An implicit numerical integration procedure of the micromechanical model equations is developed for purpose of reducing high computational times characteristic for multi-scale simulations. The developed material model is calibrated against experimental data and used in a finite element simulation of a cup drawing forming process of aluminum alloy AA6022-T4 to predict the formed cup geometry. Furthermore, the multi-scale modeling approach is utilized to study the mechanics of bending under tension deformation state as a mechanism for postponing the instabilities in deformation processes. The model of the process is capable of capturing the experimentally observed trends in mechanical response and offers insight into the microstructure evolution. The developed modeling framework is computationally intensive, but feasible
Restoration, Reconstruction and Union: memories of home in the stratiot poetry of Antonio Molino
The paper explores the notion of home in the stratiot poetry authored by 16th-century Venetian comedy author and composer Antonio Molino. Rooted in the life of the stratiots and their struggles against the Ottomans, this poetry allegedly reflects the diasporic memory of Greek stratiots, although it is apparently framed by the genre and preferences of Molino’s theatre audience. By analysing the memoryscape of notions of home which Molino linked to the Greek stratiots of his time, the paper reveals that his poetry projects, in fact, were the more tangible political ambitions of the Republic of Venice to convert the stratiots from Orthodox Christianity to Roman Catholicism, reinforce their Venetian identity and use their memory in its own aspiration to the Byzantine imperial legacy – all highly topical on the eve of the Venetian conflict with the Ottomans over Cyprus (1571–1573)
Energy efficiency features of vernacular house in Bosnia and Herzegovina: A case study of Svrzo’s house complex
This paper analyzed sustainable principles of vernacular architecture in Bosnia and Herzegovina featured in the Svrzo’s house complex in Sarajevo, which can serve as an example that can be utilized in contemporary architecture. An energy-efficiency analysis was performed by using DesignBuilder software. The aim was to investigate whether the building design, building’s envelope materialization, and spatial organization comply with today’s energy-efficiency standards and if such principles can be applied in contemporary design. The calculation of the energy demands for heating and cooling showed that the division of the house in winter and summer quarters is an energy-efficient approach that could be transposed into contemporary architecture. The calculations also showed that the materialization of the building envelope of the winter quarter is not energy efficient enough to be used in modern constructions, but the positive aspects of the building envelope materialization such as the use of natural, local materials with good heat capacity are important elements which could serve as guidelines for the materialization of contemporary buildings. Therefore, a new materialization was proposed on the basis of these principles. The calculations showed that the analyzed winter quarter became energy-efficient while maintaining sustainable principles borrowed from vernacular architecture
IN SEARCH OF THE AWESOME RIP IN PLATFORM DIVING ENTRIES
Outstanding diving performances depend upon: sound takeoff mechanics; good height; excellent form in the air; finishing the rotation well above the water; and a rip entry. Nevertheless, there is litHe doubt that it is the latter which makes a lasting impression upon the judges. When divers rip, they disappear below the surface with a minimum of splash as if they have been sucked into the water with barely a trace. Although the rip was perfected and popularized by Klaus Dibiasi, platform gold medalist in the '68, '72 and '76 Olympics, not until Gabriel's classic study (Brown et aI., 1984) was any extensive systematic research on the technique undertaken. Since then, competitive diving has evolved with an increasing number of somersaults being executed and higher performance standards expected. The objective of the present study was to gather information on how rip entries are effectively executed by competitors performing multiple somersaulting 10-m platform dives
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