Extended search for point sources of neutrinos below and above the horizon: Covering energies from TeV to EeV with IceCube

Point source searches with neutrino telescopes like IceCube are normally restricted to one hemisphere, due to the selection of up-going events as a way of rejecting the atmospheric muon background. In this work we show that the down-going region above the horizon can be included in the search by suppressing the background through energy-sensitive selection procedures. This approach increases the reach to the EeV regime of the signal spectrum, which was previously not accessible due to the absorption of neutrinos with energies above a PeV inside the Earth. We present preliminary results of this analysis, which for the first time includes up-going as well as down-going muon events in a combined approach. We used data collected with IceCube in a configuration of 22 strings. No significant excess above the atmospheric background is observed. While other analyses provided results for the Northern hemisphere, this new approach extends the field of view to a large part of the Southern sky, which was previously not covered with IceCube.Comment: 4 pages, 1 figure. To be published in the proceedings of the 2nd Heidelberg workshop "High-Energy Gamma-rays and Neutrinos from Extra-Galactic Sources", 2009 (Journal of Modern Physics D

IFEMS, an Interactive Finite Element Modeling System Using a CAD/CAM System

A method of coupling a CAD/CAM system with a general purpose finite element mesh generator is described. The three computer programs which make up the interactive finite element graphics system are discussed

Surface topographical changes measured by phase-locked interferometry

An electronic optical laser interferometer capable of resolving depth differences of as low as 30 A and planar displacements of 6000 A was constructed to examine surface profiles of bearing surfaces without physical contact. Topological chemical reactivity was determined by applying a drop of dilute alcoholic hydrochloric acid and measuring the profile of the solid surface before and after application of this probe. Scuffed bearing surfaces reacted much faster than virgin ones but that bearing surfaces exposed to lubricants containing an organic chloride reacted much more slowly. The reactivity of stainless steel plates, heated in a nitrogen atmosphere to different temperatures, were examined later at ambient temperature. The change of surface contour as a result of the probe reaction followed Arrhenius-type relation with respect to heat treatment temperature. The contact area of the plate of a ball/plate sliding elastohydrodynamic contact run on trimethylopropane triheptanoate with or without additives was optically profiled periodically. As scuffing was approached, the change of profile within the contact region changed much more rapidly by the acid probe and assumed a constant high value after scuffing. A nonetching metallurgical phase was found in the scuff mark, which was apparently responsible for the high reactivity

Surface profile changes of scuffed bearing surfaces

A phase locked interference microscope capable of resolving depth differences to 30 A and planar displacements of 6000 A was constructed for the examination of the profiles of bearing surfaces without physical contact. This instrument was used to determine surface chemical reactivity by applying a drop of dilute alcoholic hydrochloric acid and measuring the profile of the solid surface before and after application of this probe. Scuffed bearing surfaces reacted much faster than unscuffed ones, but bearing surfaces which had been previously exposed to lubricants containing an organic chloride reacted much more slowly. In a separate series of experiments, a number of stainless steel plates were heated in a nitrogen atmosphere to different temperatures and their reactivity examined later at room temperature. The change of surface contour as a result of the probe reaction followed an Arrhenius type relation with respect to heat treatment temperature. This result could have implications on the scuffing mechanism

A Policy for Science

Policy and science often interact. Typically, we think of policymakers looking to scientists for advice on issues informed by science. We may appreciate less the opposite look: where people outside science inform policies that affect the conduct of science. In clinical medicine, we are forced to make decisions about practices for which there is insufficient, inadequate evidence to know whether they improve clinical outcomes, yet the health care system may not be structured to rapidly generate needed evidence. For example, when the Centers for Medicare and Medicaid Services noted insufficient evidence to support routine use of computed tomography angiography and they called for a national commitment to completion of randomized trials, their call ran into substantial opposition. I use the computed tomography angiography story to illustrate how we might consider a “policy for science” in which stakeholders would band together to identify evidence gaps and to use their influence to promote the efficient design, implementation, and completion of high-quality randomized trials. Such a policy for science could create a culture that incentivizes and invigorates the rapid generation of evidence, ultimately engaging all clinicians, all patients, and indeed all stakeholders into the scientific enterprise

Rigorous science as the road to better public health

In the current issue of Population Health Metrics, two reports paint a bleak picture of American public health. Both physical inactivity and obesity remain highly prevalent; yet, it is not clear that increased physical activity will reduce the burden of obesity. There continue to be widespread disparities in life expectancy across United States counties. These reports appear against a backdrop of debate regarding how we should allocate our scarce resources for improving health: should we focus more on improving access to high-quality medical care, or should we instead focus on more and better public health interventions? While optimal solutions remain obscure, a look at prior successes suggests that ultimately they will come from the conduct and implementation of rigorous science, and in particular event-driven trials

Buildings as an Assembly of 3D Printed Components

This project aimed to design a series of components that would be assembled to become a house. The design is a house that is printed in a series of modules and assembled using a series of printed connectors for not only attaching the modules but also used in other various details

Quantitative evaluation of multiband photographic techniques Final report

Quantitative evaluation of multiband photographic techniques using combination of black and white and color photo

Design and Validation of Embedded Real-Time Applications

International audienceThe design and validation of embedded real-time applications is challenging, especially when legacy sub-systems are involved. To account for the uncertainty in system-development at early design stages we use statistical modelling and discrete event simulation to perform sensitivity analysis. These analysis results provide vital information about the system characteristics and indicate usage scenarios where the behaviour of the system differs significantly from the average case. Based on the simulation results and the initial system requirements a usage model for the application is being set up. The model represents the requirements in an unambiguous and traceably correct manner. For each possible path through the model, considering stimuli and their timing, a unique system reaction is defined. This way the requirements are clarified. The usage model allows the derivation of test cases that can be used in the design phase to validate the model and in the acceptance phase to test the final system. Through the combination of the simulation results and the usage modelling we are able to:•identify critical system conditions.•validate the system design w.r.t. the usage modelThe proposed methods are currently applied in both the design and validation of safety critical applications