511 research outputs found

    GEOMATICS IN BRIDGE STRUCTURAL HEALTH MONITORING, INTEGRATING TERRESTRIAL LASER SCANNING TECHNIQUES AND GEOTECHNICAL INSPECTIONS ON A HIGH VALUE CULTURAL HERITAGE

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    Abstract. The paper presents preliminary findings from a research study designed to assess the health status of a medieval bridge built on 1500 under the Medici dynasty over the river Sieve, close to Florence. The structure, a two span stone bridge with a main central pillar, experienced some restructuring interventions from 1555 to the present. The left span has been closed for some decades, and for many years the water has been allowed to float under it in case of severe flood only. At the beginning of year 2000 the left span has been opened to the regular flux of water. After opening, a maelstrom has been noticed as permanently present at the main pier's basis highlighting the presence of a fracture in the concrete base around the central pile of the bridge. In order to investigate structural health and to assess bridge's stability structural inspections and hydraulic surveys have been carried out. This manuscript reports Terrestrial Laser Scanning (TLS) survey results. Surface comparisons to identify anomalies and defromations have been carried out by exploiting Two TLS campaigns that were performed within a 6 years time span.</p

    Scapholunate interosseous ligament injury in professional volleyball players

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    Injuries to the scapholunate interosseous ligament (SLIL) are the most common cause of carpal instability. A SLIL injury typically follows a fall on an outstretched hand, with the wrist in hyperextension, ulnar deviation and intercarpal supination. We hypothesize that repetitive axial loading on the wrist in hyperextension, during the reception and digging motions of volleyball, can lead to functional overloading of the SLIL. To identify patients and to determine the clinical history and surgical treatment performed, we analyzed hospital records, X-rays, electronic databases containing all the operations performed, and image files (including before and after surgery and follow-up). We identified three SLIL injury cases in national volleyball team players, also at the libero position, who were treated at our clinic between 2007 and 2013 for scapholunate instability. Open reduction and Berger capsulodesis was performed in all cases. At a mean follow-up of 3 years (range, 22â50 months), the mean pain level on VAS was 0.3 (range, 0â1) at rest and 1.7 (range 1â2) during sport activities. The mean DASH score was 4 (range 2â5). The mean wrist flexion was 60° (range 55â70°) and extension was 80° (range 75â85°). Given the greater susceptibility of these players for developing a SLIL injury, a high index of suspicion is needed when managing athletes presenting with wrist pain or instability

    Humerus shaft fracture complicated by radial nerve palsy: Is surgical exploration necessary?

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    Fractures of the humerus shaft often are complicated by radial nerve palsy. Controversy still exists in the treatment that includes clinical observation and eventually late surgical exploration or early surgical exploration. Algorithms have been proposed to provide recommendations with regard to management of the injuries. However, advantages and disadvantages are associated with each of these algorithms. The aim of this study was to analyze the indications of each treatment options and facilitate the surgeon in choosing the conduct for each lesion, proposing our own algorithm

    Brief communication &quot;Analysis of deformations in historic urban areas using terrestrial laser scanning&quot;

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    The terrestrial laser scanning (TLS) technique has been used to accurately reconstruct the 3-D shape of the walls and bastions of the historic city of Mdina (Malta) and underlying terrain. By applying this technique it has also been possible to extract additional quantitative information regarding weathering and deformational processes affecting the structures. Thus, with the aim of identifying the main instability mechanisms, a detailed 3-D crack distribution map has been drawn and the main displacement vectors have been defined

    Contents of Volume 49

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    How kinesin waits for ATP affects the nucleotide and load dependence of the stepping kinetics

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    Dimeric molecular motors walk on polar tracks by binding and hydrolyzing one ATP per step. Despite tremendous progress, the waiting state for ATP binding in the well-studied kinesin that walks on microtubule (MT), remains controversial. One experiment suggests that in the waiting state both heads are bound to the MT, while the other shows that ATP binds to the leading head after the partner head detaches. To discriminate between these two scenarios, we developed a theory to calculate accurately several experimentally measurable quantities as a function of ATP concentration and resistive force. In particular, we predict that measurement of the randomness parameter could discriminate between the two scenarios for the waiting state of kinesin, thereby resolving this standing controversy

    Tightness for a stochastic Allen--Cahn equation

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    We study an Allen-Cahn equation perturbed by a multiplicative stochastic noise which is white in time and correlated in space. Formally this equation approximates a stochastically forced mean curvature flow. We derive uniform energy bounds and prove tightness of of solutions in the sharp interface limit, and show convergence to phase-indicator functions.Comment: 27 pages, final Version to appear in "Stochastic Partial Differential Equations: Analysis and Computations". In Version 4, Proposition 6.3 is new. It replaces and simplifies the old propositions 6.4-6.
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