2,612 research outputs found

    Static Response and Buckling Loads of Multilayered Composite Beams Using the Refined Zigzag Theory and Higher-Order Haar Wavelet Method

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    The paper presents a review of Haar wavelet methods and an application of the higher-order Haar wavelet method to study the behavior of multilayered composite beams under static and buckling loads. The Refined Zigzag Theory (RZT) is used to formulate the corresponding governing differential equations (equilibrium/stability equations and boundary conditions). To solve these equations numerically, the recently developed Higher-Order Haar Wavelet Method (HOHWM) is used. The results found are compared with those obtained by the widely used Haar Wavelet Method (HWM) and the Generalized Differential Quadrature Method (GDQM). The relative numerical performances of these numerical methods are assessed and validated by comparing them with exact analytical solutions. Furthermore, a detailed convergence study is conducted to analyze the convergence characteristics (absolute errors and the order of convergence) of the method presented. It is concluded that the HOHWM, when applied to RZT beam equilibrium equations in static and linear buckling problems, is capable of predicting, with a good accuracy, the unknown kinematic variables and their derivatives. The HOHWM is also found to be computationally competitive with the other numerical methods considered

    Monitoring and conservation of archaeological wooden elements from ship wrecks using 3D digital imaging

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    In marine archaeology, many artifacts made of metallic or organic material are found in different state of conservation depending of the environment in which they are discovered. Once brought to the surface for study or display purposes, the artifacts need to be treated properly otherwise they deteriorate in a short lapse of time. The fragility of organic artifacts and the volumetric variation caused by the marine life on or surrounding them and water lead to the need for measuring the physical dimensions soon after an artifact is extracted from the sea. In an ideal context, it would be appropriate to preserve and restore the archaeological elements rapidly and with the latest methods but due to the large number of artifacts, the cost of complete restoration activities becomes prohibitive for the funding available in public institutions. For this reason, many public laboratories are resorting to digital technologies for documentation, restoration, display and conservation. In this paper, we illustrate the experience of the University of Salento in this area of archaeology using 3D imaging technology. The interest sprang from the need to develop a protocol for documentation and digital restoration of archaeological finds discovered along the coast of Torre S. Sabina (BR) Italy

    Underground Muon Physics with the MACRO experiment

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    Underground muon events detected by the MACRO experiment at Gran Sasso have been studied for different purposes. The studies include the vertical muon intensity measurement, multiplicity distribution, lateral and angular muon distribution and searches for substructures inside muon bundles. These analyses have contributed to bring new insights in cosmic ray physics, in particular in the framework of primary cosmic ray composition studies. Moreover, this activity allows the testing and tuning of Monte Carlo simulations, in particular for aspects associated with models of hadronic interactions and muon propagation through the rock.Comment: 6 pages, 4 EPS figures included with epsfig, uses espcrc2.sty Talk given at the Sixth Topical Seminar on Neutrino and Astroparticle Physics, San Miniato, Italy, 17-21 May 199

    Molecular Detection of Babesia spp. (Apicomplexa: Piroplasma) in Free-Ranging Canids and Mustelids From Southern Italy.

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    Babesiosis is an emerging tick-borne disease caused by apicomplexan parasites with widespread geographical distribution and various wildlife species as reservoir hosts. The aims of this study were to investigate the prevalence and assess the role of free-ranging canids and mustelids in the maintenance of Babesia spp. in southern Italy. PCR analysis of splenic samples targeting the 18S rRNA gene revealed the presence of Babesia spp. in 36 of 82 (43.9%) red foxes (Vulpes vulpes) including 29 (58%) from Campania region and seven (21.8%) from Calabria region, in seven of 13 (53.8%) Eurasian badgers (Meles meles), and in one of 13 (7.7%) gray wolves (Canis lupus). Samples from other host species including 9 Eurasian otters (Lutra lutra), 1 stone marten (Martes foina), 1 least weasel (Mustela nivalis), and 1 European polecat (Mustela putorius) tested Babesia spp. negative. Sequence analysis of the 18S rRNA gene demonstrated the presence of B. vulpes in the red fox and two sequence types of badger-associated Babesia spp. in the Eurasian badger. The Babesia sp. sequence detected in the gray wolf was identical to a badger-associated Babesia sp. This study shows that the number of Babesia spp. infecting free-ranging carnivores in Italy is higher than currently believed, and suggests that these hosts may play an important role in the maintenance of the sylvatic cycle of these parasites. It is the first report of badger-associated Babesia spp. in Italy and in a gray wolf
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