305 research outputs found

    Numeričko predviđanje izobličenja nakon zavarivanja s različnim slijedom zavarivanja i spajanja

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    Welding simulation of a test cover for hydropower plant was made due to very large dimensions of the cover. The main aim was to predict distortion after welding in order to avoid machining the cover. Welding process was simulated with the Sysweld program to keep distortion in desired limits. Various welding sequences and clamping conditions were calculated to reduce the distortion. Calculation of microstructure constituents in virtual complex geometry of joints was also analyzed.Simulacija zavarivanja testnog pokrova hidroelektrane provedena je zbog velikih dimenzija ispitne prevlake. Osnovni je cilj predvidjeti izobličenje nakon zavarivanja. Radi postizanja veličine izobličenja u željenim granicama proces zavarivanja je simuliran programom Sysweld. Različiti tijekovi zavarivanja i uvjeta spajanja prorač unati su radi smanjenja izobličenja. Određivanje mikrostrukturnih konstituenata u virtualnoj komleksnoj geometriji spojeva je također provedeno

    Integrating geologic fault data into tsunami hazard studies

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    We present the realization of a fault-source data set designed to become the starting point in regional-scale tsunami hazard studies. Our approach focuses on the parametric fault characterization in terms of geometry, kinematics, and assessment of activity rates, and includes a systematic classification in six justification levels of epistemic uncertainty related with the existence and behaviour of fault sources. We set up a case study in the central Mediterranean Sea, an area at the intersection of the European, African, and Aegean plates, characterized by a complex and debated tectonic structure and where several tsunamis occurred in the past. Using tsunami scenarios of maximum wave height due to crustal earthquakes (Mw=7) and subduction earthquakes (Mw=7 and Mw=8), we illustrate first-order consequences of critical choices in addressing the seismogenic and tsunamigenic potentials of fault sources. Although tsunamis generated by Mw=8 earthquakes predictably affect the entire basin, the impact of tsunamis generated by Mw=7 earthquakes on either crustal or subduction fault sources can still be strong at many locales. Such scenarios show how the relative location/orientation of faults with respect to target coastlines coupled with bathymetric features suggest avoiding the preselection of fault sources without addressing their possible impact onto hazard analysis results

    Interseismic ground velocities in Central Apennines from GPS and InSAR measurements: new contributions for seismic hazard models by preliminary results of ESA CHARMING project

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    The contribution of space geodetic techniques to interseismic velocity estimation, and thus seismic hazard modelling, has been recognized since two decades and made possible in more recent years by the increased availability and accuracy of geodetic measurements. We present the preliminary results of a feasibility study performed within the CHARMING project (Constraining Seismic Hazard Models with InSAR and GPS), funded by the European Space Agency (ESA). For a 200 km x 200 km study area, covering the Abruzzi region (central Italy) we measure the mean surface deformation rates from Synthetic Aperture Radar and GPS, finding several local to regional deformation gradients consistent with the tectonic context. We then use a kinematic finite element model to derive the long-term strain rates, as well as earthquake recurrence relations. In turn these are input to state-of-the-art probabilistic seismic hazard models, the output of which is validated statistically using data from the Italian national accelerometric and macroseismic intensity databases.Published373-3773T. Pericolosità sismica e contributo alla definizione del rischioN/A or not JCRope

    Mid-term review results of the ESA STSE Pathfinder CHARMING project (Constraining Seismic Hazard Models with InSAR and GPS)

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    We probe the feasibility of integrating GPS and Synthetic Aperture Radar deformation rates within the seismic hazard models of the central Apennines (Italy), exploiting data from over 100 GPS stations and the ~20- year long ERS and ENVISAT SAR image archive. We then use a kinematic finite element model to derive the long-term strain rates, as well as earthquake recurrence relations. In turn these are input to state-of-the-art probabilistic seismic hazard models, the output of which is validated statistically using data from the Italian national accelerometric and macroseismic intensity databases.Published23-273T. Pericolosità sismica e contributo alla definizione del rischioN/A or not JCRrestricte

    Associations among serum pro- and anti-inflammatory cytokines, metabolic mediators, body condition, and uterine disease in postpartum dairy cows

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    BACKGROUND: Adipose tissue is an active endocrine organ which secretes a wide range of hormones and protein factors, collectively termed adipokines. Adipokines affect appetite and satiety, glucose and lipid metabolism, inflammation and immune functions. The objectives were to evaluate serum concentrations of adipokines (adiponectin, leptin, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6) in lactating dairy cows with postpartum uterine inflammatory conditions (metritis, clinical endometritis or subclinical endometritis) and in cows experiencing loss of body condition, and to assess the relationship of adipokines and body condition loss in the establishment of persistent uterine inflammatory conditions. METHODS: Lactating multiparous Holstein cows (N = 40), with body condition scores (BCS) from 2 to 4 (eight cows for each 0.5 score increment) were enrolled. Body condition was monitored for all cows weekly for 7 weeks post calving; cows with uterine inflammatory conditions were also re-evaluated 2 weeks later. Blood samples were collected from 1 week prior to calving to 7 weeks after calving for determination of serum concentrations of adipokines, insulin and insulin like growth factor (IGF)-1. RESULTS: Cows with metritis or clinical endometritis had higher serum concentrations of adiponectin, leptin, TNF-alpha, IL-1beta and IL-6 compared to normal cows (P < 0.05). Furthermore, serum leptin, TNF-alpha, IL-1beta and IL-6 were higher in cows with subclinical endometritis compared to normal cows (P < 0.05), and insulin and IGF-1 concentrations were lower in cows with metritis or clinical endometritis. Cows with low BCS (2 and 2.5) had significantly higher adiponectin, TNF-alpha, IL-1beta and IL-6 than those with high BCS (3 to 4). Cows with persistent uterine inflammatory conditions had higher adiponectin, leptin TNF-alpha, IL-1beta and IL-6 and insulin compared to normal and spontaneously recovered cows, except for IGF-1 (P < 0.05). CONCLUSIONS: Serum concentrations of adipokines, insulin, and IGF-1 had significant associations with BCS categories (low vs. high) and postpartum uterine inflammatory conditions. Perhaps loss of body condition mediated increases in anti- and pro-inflammatory cytokines, whereas increased pro- and anti-inflammatory cytokines concentrations mediated body condition loss and thereby prolonged persistence of uterine inflammation in dairy cows
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