Measuring Atmospheric Neutrino Oscillations with Neutrino Telescopes

Neutrino telescopes with large detection volumes can demonstrate that the current indications of neutrino oscillation are correct or if a better description can be achieved with non-standard alternatives. Observations of contained muons produced by atmospheric neutrinos can better constrain the allowed region for oscillations or determine the relevant parameters of non-standard models. We analyze the possibility of neutrino telescopes measuring atmospheric neutrino oscillations. We suggest adjustments to improve this potential. An addition of four densely-instrumented strings to the AMANDA II detector makes observations feasible. Such a configuration is competitive with current and proposed experiments.Comment: 36 pages, 21 figures, revte

Mechanical Properties and Microstructural Characterization of Aged Nickel-based Alloy 625 Weld Metal

The aim of this work was to evaluate the different phases formed during solidification and after thermal aging of the as-welded 625 nickel-based alloy, as well as the influence of microstructural changes on the mechanical properties. The experiments addressed aging temperatures of 650 and 950 A degrees C for 10, 100, and 200 hours. The samples were analyzed by electron microscopy, microanalysis, and X-ray diffraction in order to identify the secondary phases. Mechanical tests such as hardness, microhardness, and Charpy-V impact test were performed. Nondestructive ultrasonic inspection was also conducted to correlate the acquired signals with mechanical and microstructural properties. The results show that the alloy under study experienced microstructural changes when aged at 650 A degrees C. The aging was responsible by the dissolution of the Laves phase formed during the solidification and the appearance of gamma aEuro(3) phase within interdendritic region and fine carbides along the solidification grain boundaries. However, when it was aged at 950 A degrees C, the Laves phase was continuously dissolved and the excess Nb caused the precipitation of the delta-phase (Ni3Nb), which was intensified at 10 hours of aging, with subsequent dissolution for longer periods such as 200 hours. Even when subjected to significant microstructural changes, the mechanical properties, especially toughness, were not sensitive to the dissolution and/or precipitation of the secondary phases

Extensive Air Showers from Ultra High Energy Gluinos

We study the proposal that the cosmic ray primaries above the Greisen-Zatsepin-Kuzmin (GZK) cutoff are gluino-containing hadrons ($\tilde g$-hadrons). We describe the interaction of $\tilde g$-hadrons with nucleons in the framework of the Gribov-Regge approach using a modified version of the hadronic interaction model QGSJET for the generations of Extensive Air Showers (EAS). There are two mass windows marginally allowed for gluinos: m_{\tilde g}\lsim 3 GeV and 25\lsim m_{\tilde g}\lsim 35 GeV. Gluino-containing hadrons corresponding to the second window produce EAS very different from the observed ones. Light $\tilde g$-hadrons corresponding to the first gluino window produce EAS similar to those initiated by protons, and only future detectors can marginally distinguish them. We propose a beam-dump accelerator experiment to search for $\tilde g$-hadrons in this mass window. We emphasize the importance of this experiment: it can discover (or exclude) the light gluino and its role as a cosmic ray primary at ultra high energies.Comment: 27 pages latex, 13 eps figure

The Pierre Auger Cosmic Ray Observatory

The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world׳s largest cosmic ray observatory. The objectives of the Observatory are to probe the origin and characteristics of cosmic rays above 10¹⁷ eV and to study the interactions of these, the most energetic particles observed in nature. The Auger design features an array of 1660 water Cherenkov particle detector stations spread over 3000 km² overlooked by 24 air fluorescence telescopes. In addition, three high elevation fluorescence telescopes overlook a 23.5 km², 61-detector infilled array with 750 m spacing. The Observatory has been in successful operation since completion in 2008 and has recorded data from an exposure exceeding 40,000 km² sr yr. This paper describes the design and performance of the detectors, related subsystems and infrastructure that make up the Observatory.A. Aab ... K.B. Barber ... J.A. Bellido ... S.G. Blaess ... R.W. Clay ... M.J. Cooper ... B.R. Dawson ... T.D. Grubb ... G.C. Hill ... M. Malacari ... P.H.Nguyen ... S.J. Saffi ... A.G.K. Smith ... J. Sorokin ... P. van Bodegom, ... N.Wild ... et al. (Pierre Auger Collaboration

Prevalence and costs of hospitalizations for poisoning and accidental intoxication in Brazilian elderly

A cross-sectional study of secondary data/information obtained from the Hospital Information System (HIS) spanning the years 2008 - 2009 was performed. The distribution of the main hospital admissions by gender, age, color/race, region and federal unit of residence, average expenditure and average length of hospital stay, year of hospitalization and mortality rates (MR) were studied. The data collected were tabulated by TabNet and keyed into Microsoft Excel 2007. It was verified that elderly males (54.3%), from 60 to 69 years old (50.6%), nonwhites (36.3%) and residents of Southeast and North regions of the country had the highest rates of hospitalization. Seniors were hospitalized for an average of 4.8 days, and the major causes were exposure to alcohol (43.7%) and to drugs (33.9%). Expenses related to hospital admissions were, on average, R$ 529,817.70. The highest mortality rates were recorded among females (MR = 4.34), in elderly, 80 years or older (MR = 10.16) and Caucasians (MR = 3.95), where pharmacological substances with action on the Autonomic Nervous System were the leading cause of death. There are demographic differences in morbi-mortality of these elderly since, although men and younger elderly were the main victims, women and elderly of advanced age have greater mortality. The leading causes of hospitalization were alcohol and drugs