1,721,442 research outputs found
Impact, language communities and archaeological schools: British Archaeologists and Italian Neolithic studies
No full textHard cheese: upland pastoralism in the Italian Bronze and Iron Ages
Get PDFBy moving livestock to summer farms, fodder at the home base is saved but the milk and other animal products produced during the animals’ absence are no longer immediately available to those left at the home base. In this paper I shall explore the economic implications of the use of summer farms, in particular the effect on carrying capacity, on the number of livestock which can be over-wintered, and on the use of the milk produced while the animals are at the summer grazing lands.
I then explore archaeological evidence from the Bronze and Iron Ages of the Italian uplands (Apennines and Alps). I argue that the production of hard cheese, which converts milk into an easily conservable and transportable commodity, is key to the expansion of summer farms in the Bronze Age of Italy. Cheese production is an essential part of models for the pastoral use of Mediterranean uplands in prehistory but it is commonly held that in the Alps the production of hard cheese only begins in the Middle Ages. I examine the literary and archaeological evidence for the prehistoric production of hard cheese and argue that its production in prehistory is the most parsimonious explanation for the summer use of high mountain pastures and thus for the origins of the Alpwirtschaft economy in the southern Alps
Development of the boundary conditions required for simulating a wave tank using smoothed particle hydrodynamics
No full textSmoothed Particle Hydrodynamics, SPH, is a Lagrangian method that has been applied to a number of fields including maritime applications. However little work has been done concerning the simulation of the motion of ships' hulls. A weakness of SPH is in the modelling of boundaries, both permeable and impermeable. This thesis investigates some of the latest SPH methods used to simulate these boundaries. Particular emphasis is placed upon the development of an approach that idealises the permeable inflow and outflow boundaries of a domain that are required to simulate the boundaries of a wave tank.In the method presented the inflow boundary has been designed such that it can also generate waves. This allows for the simulation of a ship hull subject to head waves. The inflow boundary is also capable of creating a mean flow speed along with the wave generation. The outflow boundary serves as both a plane which allows particles that have crossed it to be removed and also incorporates a sponge layer that is designed to damp out incoming waves and prevent any unphysical wave reflection. These developments, used together, allow a small section of a wave tank to be simulated, this requires a minimum of computational resources.Each new development has been tested against published data from experiments or numerical simulation. The computational models discussed in this thesis compare the performance of the new approach against experimental data and simulations using both classic SPH and Reynolds-Averaged Navier-Stokes methods. The wave generation and damping methods have been compared against the motion predicted by the Airy wave theory. The hull motion simulations have been compared against Wigley hull experimental data
Il Protovillanoviano al di qua e al di là dell'Appennino
No full textatti della giornata di studio: Pavia, 17 giugno 199
Prediction of ship motions for a Wigley hull using SPH
No full textThis paper outlines a framework that will allow SPH to be used to simulate the motion of a Wigley hull. A number of modifications and novel additions to the open source SPH code SPHysics are proposed to enable this simulation to be carried out. These are a modified wavemaker, a novel non-reflecting open boundary condition and the inclusion of the Wigley hull geometry. The results from two validation test cases are used to verify the capability of these new methods. Firstly a plunger dropped into a wave tank to test the non-reflecting open boundary. Secondly a Wigley hull in regular waves to demonstrate the combination of new techniques applicable to ship motion simulation
Using SPHysics to simulate a Wigley hull in head waves
No full textThis paper describes a novel methodology, using the open source SPH code SPHysics, that is capable of simulating the motion of a Wigley hull in a wave tank. To achieve this capability a number of modifications made and new features added. These are a Wigley hull geometry modelled as a floating body, a new inflow condition based on the Airy wave theory and a two-part outflow condition that acts as a non-reflecting open boundary. To verify the capability of the new methods a series of test cases have been conducted. These are 2D and 3D wave tank simulations to test the inflow and outflow conditions and finally a Wigley hull is simulated in a wave tank to test all of the new methods simultaneously
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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