1,721,781 research outputs found
The geological map of Sardinia (Italy) at 1:250,000 scale
Full text linkOver the last 25 years the Italian national geological mapping program of the Italian Geological Survey (CARG Project, italian: Progetto Carta Geologica) at 1:50,000 scale has led to significant improvements in the geological knowledge for the Island of Sardinia (Italy). As a result, about one half of the island now is covered by new geological maps with 1:10,000–1:25,000 accuracy and geological maps at the 1:50,000 scale whose explanatory notes are available electronically. At the beginning of the CARG Project a geological map for Sardinia Island at 1:200,000 scale was published [Carmignani, L. (1996). Carta Geologica della Sardegna (1:200.000). Servizio Geologico Nazionale, Regione Autonoma della Sardegna], summarizing all the geological information available at that time, and a book with explanatory notes for the map was later published [Carmignani, L., Oggiano, G., Barca, S., Conti, P., Salvadori, I., Eltrudis, ... Pasci, S. (2001). Geologia della Sardegna: Note Illustrative della Carta Geologica della Sardegna in scala 1:200.000, Memorie Descrittive della Carta Geologica d'Italia (Vol. 60). Roma: Servizio Geologico d'Italia, 283 pp]. The enclosed Geological map of Sardinia at 1:250,000 scale incorporates all maps of the CARG Project, unpublished author studies and recently published maps and represents the most updated synthesis of an area characterised by a complex geological evolution that, with few exceptions, can be considered continuous during the last 540 Ma. The main events that influenced the geology of the island are the Variscan orogen that deeply involved the passive margin of North Gondwana and then the complex episodes that occurred in the present-day Mediterranean area after the accretion of Pangea up to the opening of the Tyrrhenian basin
Robo-Yacht: a human behaviour-based tool to predict the performances of yacht-crew systems
Full text linkMany numerical tools are available in the yacht design domain to predict yacht performances. These are based on experimental data and well-established numerical techniques. However, being competitive sailing an uncertainty-rich discipline, there is also a need to assess the performances of a yacht’s crew. This is indeed the main area for performance gains. The present study aims at predicting the performances of yacht-crew systems, by including numerical models for human behaviour within those referred to the yacht dynamics.
In particular, the problem of decision-making under weather uncertainty is formulated in terms of a game of chance having nature as a second player and involving risk. Within this context, it is shown that decisionmaking models often used in management sciences can be advantageously used. This approach has led to the development of a sailing simulator referred to as ‘Robo-Yacht’, based on the International America’s Cup Class. A case study is investigated that involves three strategical alternatives and four possible weather scenarios: gains and losses are assessed through the simulator and a formula to express expected payoffs is derived. When different attitudes towards risk (neutral, risk-averse and risk-taking) are expressed as different utility functions,
it is shown that sailors’ choices can be conveniently modeled based on a maximization of expected utility. The ‘automatic crew’ can actually make decisions that appear to be consistent with widely accepted principles of race strategy. A risk function is also derived in order to take into account opponents’ choices and, where necessary, modify the strategic plan accordingly
Repeated change from crustal shortening to orogen-parallel extension in the Austroalpine units of Graub"unden
No full textThe structural analysis of the Austroalpine units in Graubunden reveals the existence of two orogenic cycles, Cretaceous and Tertiary in age, both including thrusting followed by extensional overprint. Such extensional faulting occurred in the Late Cretaceous and in the Early to Mid-Oligocene. In both episodes, the direction of extension was parallel to the strike of the Alpine chain. Five stages of the tectonic evolution are described. The recognition of two orogenic cycles contradicts the classical view that the Alpine orogeny involves a continuous tectonometamorphic evolution from Cretaceous subduction and high-pressure metamorphism to Tertiary exhumation and Barrow-type metamorphism. Instead, it is postulated that nappe formation related to subduction and exhumation associated with extension occurrred twice during the Alpine orogeny. -from Author
FATIGUE CRACK-GROWTH BEHAVIOR OF 4 STRUCTURAL-STEELS IN AIR AND IN A GEOTHERMAL FLUID ENVIRONMENT
No full textIn recent years the exploitation of geothermal energy has expanded rapidly in Italy. This has created a requirement for improved drilling technology, to reduce the number of failures occurring in the drills, which is more frequent than in oil wells. This paper deals with the results obtained in FCCR tests of four materials both in air and in two types of aggressive environments. Deterioration takes place by fatigue, corrosion fatigue and hydrogen embrittlement. It is concluded that the steel G105 is a suitable substitute for S135 in drill pipes, and inspections between drillings may be adequate to prevent failure for small-curvature wells
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