Statistical emulation of a tsunami model for sensitivity analysis and uncertainty quantification

Due to the catastrophic consequences of tsunamis, early warnings need to be issued quickly in order to mitigate the hazard. Additionally, there is a need to represent the uncertainty in the predictions of tsunami characteristics corresponding to the uncertain trigger features (e.g. either position, shape and speed of a landslide, or sea floor deformation associated with an earthquake). Unfortunately, computer models are expensive to run. This leads to significant delays in predictions and makes the uncertainty quantification impractical. Statistical emulators run almost instantaneously and may represent well the outputs of the computer model. In this paper, we use the Outer Product Emulator to build a fast statistical surrogate of a landslide-generated tsunami computer model. This Bayesian framework enables us to build the emulator by combining prior knowledge of the computer model properties with a few carefully chosen model evaluations. The good performance of the emulator is validated using the Leave-One-Out method

Search of the Higgs boson decaying into tau-leptons at ATLAS

The search for the Higgs boson is one of the main goals of the Large Hadron Collider experiments. Both in the Standard Model (SM) and in its minimal supersymmetric extensions (MSSM), one or several new bosons are expected as manifestations of the Higgs fi eld. The tau lepton will be essential for Higgs(es) discovery. In fact, both in SM and in the MSSM, the Higgs boson(s) decaying into tau-pairs is one of the favourite discovery channels, especially at low masses. The discovery potential of the ATLAS experiment for neutral Higgs bosons decaying into tau-pairs is shown both in the SM and the MSSM. For the latter, the results on the charged Higgs boson decaying into tau plus neutrino are also discussed

Measurements of Light Higgs Couplings at ATLAS

Once discovered, Higgs properties have to be determined. The variuos Higgs couplings determine Higgs production cross sections and decay branching fraction. By measuring the rates of mupltiple channels, various combination of the couplings can be determined. In this talk Higgs different cupling measurements and their uncertainties are shown for an amount of data of 300fb-1, using different theoretical assumptions. The experimental data foresee a light Higgs (114 GeV < MH <200 GeV) and the shown analysis refers to this mass range

Oral administration of chestnut tannins to reduce the duration of neonatal calf diarrhea

Background: Neonatal calf diarrhea is generally caused by infectious agents and is a very common disease in bovine practice, leading to substantial economic losses. Tannins are known for their astringent and anti- inflammatory properties in the gastro-enteric tract. The aim of this study was to evaluate the effect of the oral administration of chestnut tannins (Castanea sativa Mill.) in order to reduce the duration of calf neonatal diarrhea. Twenty-four Italian Friesian calves affected by neonatal diarrhea were included. The duration of the diarrheic episode (DDE) was recorded and the animals were divided into a control group (C), which received Effydral® in 2 l of warm water, and a tannin-treated group (T), which received Effydral® in 2 l of warm water plus 10 g of extract of chestnut tannins powder. A Mann-Whitney test was performed to verify differences for the DDE values between the two groups. Results: The DDE was significantly higher in group C than in group T (p = 0.02), resulting in 10.1 ± 3.2 and 6.6 ± 3. 8 days, respectively. Conclusions: Phytotherapic treatments for various diseases have become more common both in human and in veterinary medicine, in order to reduce the presence of antibiotic molecules in the food chain and in the environment. Administration of tannins in calves with diarrhea seemed to shorten the DDE in T by almost 4 days compared to C, suggesting an effective astringent action of chestnut tannins in the calf, as already reported in humans. The use of chestnut tannins in calves could represent an effective, low-impact treatment for neonatal diarrhea

Multi-response Optimization of Laser Welding of Stainless Steels in a Constrained Fillet Joint Configuration Using RSM

This paper presents experimental design approach to process parameter optimization for CW Nd/YAG laser welding of ferritic/austenitic stainless steels in a constrained fillet configuration. To determine the optimal welding parameters, response surface methodology was used to develop a set of mathematical models relating the welding parameters to each of the weld characteristics. The quality criteria considered to determine the optimal settings were the maximization of weld resistance length and shearing force, and the minimization of weld radial penetration. Laser power, welding speed, and incident angle are the factors that affect the weld bead characteristics significantly. A rapid decrease in weld shape factor and increase in shearing force with the line energy input in the range of 15-17 kJ/m depicts the establishment of a keyhole regime. A focused beam with laser power and welding speed respectively in the range of 860-875 W and 3.4-4.0 m/min and an incident angle of around 12° were identified as the optimal set of laser welding parameters to obtain stronger and better welds

Laser beam welding of dissimilar stainless steels in a fillet joint configuration

This paper investigates laser beam welding of dissimilar AISI 304L and AISI 430 stainless steels. Experimental studies were focused on effects of laser power, welding speed, defocus distance, beam incident angle, and line energy on weld bead geometry and shearing force. Metallurgical analysis was conducted on a selected weld only to show various microstructures typically formed at different zones and consequent change in microhardness. Laser power and welding speed were the most significant factors affecting weld geometry and shearing force. All the bead characteristics but radial penetration depth decreased with increased beam incident angle. The focused beam allowed selecting lower laser power and faster welding speed to obtain the same weld geometry. Weld shape factor increased rapidly due to keyhole formation for line energy input ranging from 15 kJ/m to 17 kJ/m. Fusion zone microstructures contained a variety of complex austenite-ferrite structures. Local microhardness of fusion zone was greater than that of both base metals