Detection of Near Horizontal Muons with the HAWC Observatory

The HAWC (High Altitude Water Cherenkov) gamma ray observatory is able to observe muons with nearly horizontal trajectories. HAWC is located at an altitude of 4100 meters a.s.l. on the Sierra Negra volcano in Mexico. The HAWC detector is composed of 300 water tanks, each 7.3 m in diameter and 4.5 m tall, densely packed over a physical area of 22,000 m$^{2}$. Previous and current experiments have observed high zenith angle (near horizontal) muons at or near sea level. HAWC operates as a hodoscope able to observe multi-TeV muons at zenith angles greater than 75 degrees. This is the first experiment to measure near horizontal muons at high altitude and with large ($\geq$ 10 m) separations for multiple muons. These muons are distinguishable from extensive air showers by observing near horizontal particles propagating with the speed of light. The proximity of Sierra Negra and Pico de Orizaba volcanoes provides an additional measurement of muons with rock overburdens of several km water equivalent. We will present the angular distribution and rate at which HAWC observes these muon eventsComment: Presented at the 35th International Cosmic Ray Conference (ICRC2017), Bexco, Busan, Korea. See arXiv:1708.02572 for all HAWC contribution

Simulation of Near Horizontal Muons and Muon Bundles for the HAWC Observatory with CORSIKA

The HAWC (High Altitude Water Cerenkov) gamma ray observatory observes muons with nearly-horizontal trajectories corresponding to zenith angles greater than $80^{0}$. HAWC is located at an altitude of 4100 meters a.s.l. (70 deg. atmospheric depth of 2400 g/cm$^{2}$) on the extinct volcano, Sierra Negra in Mexico. In this poster, we summarize the CORSIKA and GEANT4 as well as toy-model based simulations performed to determine the effective area of HAWC to muons from high zenith angle cosmic ray primaries. We are developing an updated GEANT4 based detector response simulation that includes a model of the volcanoes that are located near HAWC. These simulations are investigating the capability to use muon multiplicity and rates to differentiate between the primary particle composition (proton or iron) and measure the primary energy.Comment: Presented at the 35th International Cosmic Ray Conference (ICRC2017), Bexco, Busan, Korea. See arXiv:1708.02572 for all HAWC contribution

Effects of rarefaction on cavity flow in the slip regime

The Navier-Stokes-Fourier equations, with boundary conditions that account for the effects of velocity-slip and temperature-jump, are compared to the direct simulation Monte Carlo method for the case of a lid-driven micro-cavity. Results are presented for Knudsen numbers within the slip-flow regime where the onset of nonequilibrium effects are usually observed. Good agreement is found in predicting the general features of the velocity field and the recirculating flow. However, although the steady-state pressure distributions along the walls of the driven cavity are generally in good agreement with the Monte Carlo data, there is some indication that the results are starting to show noticeable differences, particularly at the separation and reattachment points. The modified Navier-Stokes-Fourier equations consistently overpredict the maximum and minimum pressure values throughout the slip regime. This highlights the need for alternative boundary formulations or modeling techniques that can provide accurate and computationally economic solutions over a wider range of Knudsen numbers

Micro-scale cavities in the slip - and transition - flow regimes

Differences between Navier-Stokes-Fourier (NSF) slip/jump solutions and direct simulation Monte-Carlo (DSMC) computations are highlighted for a micro lid-driven cavity problem. The results indicate a need for better modelling techniques which at the same time retain low computational cost of NSF models. We also highlight the fact thatmany micro-flows that have been considered are simple planar flows and typical classification systems are defined on such flows. We show that for complex flows, such as thedriven cavity, non-equilibrium effects are more appreciable and their onset occurs at lower Knudsen numbers than expected

An Independent and External Validation of the ACC NCDR Bleeding Risk Score among a National Multi-Site Community Hospital Registry of Cardiac Interventions

Background: An accurate tool with good discrimination for bleeding would be useful to clinicians for improved management of all their patients. Bleeding risk models have been published but not externally validated in independent clinical dataset. We chose the NCDR PCI score to validate within a large, multi-site community datasets. The aim of the study was to determine the diagnostic utility of this bleeding risk score tool. Methods: This is a large-scale retrospective analysis utilizing American College of Cardiology data from a 37-hospital health system. The central repository of PCI procedures between 6-1-2009 and 6-30-2012 was utilized to validate the NCDR PCI bleeding risk score (BRS) among 4693 patients. The primary endpoint was major bleeding. Discriminant analysis calculating the receiver operating characteristic curve was performed. Results: There were 143 (3.0%) major bleeds. Mean bleeding risk score was 14.7 (range 3 - 42). Incidence of bleeding by risk category: low (0.5%), intermediate (1.7%), and high risk (7.6%). Patients given heparin had 113 (3.7%) major bleeds and those given bivalirudin had 30 (2.1%) major bleeds. Tool accuracy was poor to fair (AUC 0.78 heparin, 0.65 bivalirudin). Overall accuracy was 0.71 (CI: 0.66-0.76). Accuracy did not improve when confined to just the intermediate risk group (AUC 0.58; CI: 0.55-0.67). Conclusion: Bleeding risk tools have low predictive value. Adjustment for anticoagulation use resulted in poor discrimination because bivalirudin differentially biases outcomes toward no bleeding. The current state of bleeding risk tools provides little support for diagnostic utility in regards to major bleeding and therefore have limited clinical applicability

Examination of Beluga-habitat Relationships through the Use of Telemetry and a Geographic Information System

The spatial and temporal relationships between belugas (Delphinapterus leucas) and two characteristics of their habitat - bathymetry and ice concentration - were examined. Observed location-habitat correspondence histograms were compared to random location-habitat histograms, using a Kolmogorov-Smirnoff (K-S) statistical test. Results show that beluga distribution is bimodal with respect to bathymetry, with a larger mode in shallow water and a smaller mode in water approximately 500 m deep. They occur more often than expected by chance in the 0/10 ice class and less often than expected in the 10/10 ice class. Males and females associate differently with both depth and ice concentration. Females associate with bathymetry very differently in the fall than in the summer. There is a general tendency for males in the eastern North American Arctic to be associated with shallow water during the summer and deeper water (modes at 100 and 500 m) in the fall. Female locations are associated more often with the 0/10 ice class and less often with the 10/10 class than expected by chance. These trends were stronger in the western than in the eastern portions of the Canadian Arctic.On a étudié les rapports spatiaux et temporels entre les bélougas (Delphinapterus leucas) et deux caractéristiques de leur habitat (bathymétrie et concentration de glace). À l'aide d'un test statistique de Kolmogorov-Smirnov (K-S), on a comparé les histogrammes de la correspondance observée emplacement-habitat à des histogrammes emplacement-habitat pris au hasard. Les résultats montrent que la distribution du bélouga est bimodale en ce qui a trait à la bathymétrie, un mode plus grand étant associé à l'eau peu profonde et un mode plus petit à l'eau profonde d'environ 500 m. On les trouve plus fréquemment qu'on ne peut le prédire au hasard dans de la glace de cote 0/10 et moins souvent dans de la glace de cote 10/10. Les mâles et les femelles s'associent différemment selon la profondeur comme la concentration de glace. Les femelles s'associent très différemment avec la bathymétrie en automne et en été. Dans les mers arctiques de l'Amérique du Nord orientale, il y a une tendance générale pour les mâles à s'associer aux eaux peu profondes durant l'été et aux eaux plus profondes (modes à 100 et 500 m) en automne. Les emplacements des femelles sont associés plus souvent à la glace de cote 0/10 et moins souvent à la cote 10/10 qu'on ne peut le prédire au hasard. Ces tendances étaient plus marquées dans les parties occidentales que dans les zones orientales de l'Arctique canadien

Simulation of Micro-Electronic FlowFET Systems

A microelectronic fluidic system has been investigated by modeling and 3D simulation of fluid flow controlled by an applied gate voltage. The simulations have helped to characterize a novel FlowFET (a fluidic Field Effect Transistor) device under fault-free conditions. The FlowFET operates by applying a voltage field from a gate electrode in the insulated side wall of a microchannel to modulate the ␣-potential at the shear plane [1]. The change in ␣-potential can be used to control both the magnitude and direction of the electroosmotic flow in the microchannel

Analysis of electromagnetic interference from power system processing and transmission components for Space Station Freedom

The goal of this research project was to analyze the potential effects of electromagnetic interference (EMI) originating from power system processing and transmission components for Space Station Freedom. The approach consists of four steps: (1) developing analytical tools (models and computer programs); (2) conducting parameterization (what if?) studies; (3) predicting the global space station EMI environment; and (4) providing a basis for modification of EMI standards