Pavement stresses due to tire impact

Road surfaces wear continually under the effects of vehicular motions in an environment of changing temperature, humidity, etc. Regulatory agencies need to set limits on vehicular loads, tire pressures, etc., in order to mitigate the damage caused by the traveling stress footprints of vehicular traffic. In order to understand and quantify the relationship between damage caused and the parameters influencing the forces generated by a moving vehicle on a road surface, it is necessary to construct a model for a mechanical system of vehicle body, suspension springs, axle, wheel rim and tire, transmitting forces back and forward to the road surface. The previous paragraph describes the broad problem presented to the workshop. In what follows we organize a simple mathematical model to represent the major components of the system, and we indicate how this model may be validated (or not) by tests and, if it is successful, how it can be used in a predictive capacity

Cavity flow past a slender pointed hydrofoil

A slender-body theory for the flow past a slender, pointed hydrofoil held at a small angle of Attack to the flow, with a cavity on the upper surface, has been worked out. The approximate solution valid near the body is seen to be the sum of two components. The first consists of a distribution of two-dimensional sources located along the centroid line of the cavity to represent the variation of the cross-sectional area of the cavity. The second component represents the crossflow perpendicular to the centroid line. It is found that over the cavity boundary which envelops a constant pressure region, the magnitude of the cross-flow velocity is not constant, but varies to a moderate extent. With this variation neglected only in the neighbourhood of the hydrofoil, the cross-flow is solved by adopting the Riabouchinsky model for the two-dimensional flow. The lift is then calculated by integrating the pressure along the chord; the dependence of the lift on cavitation number and angle of attack is shown for a specific case of the triangular plan form

Handgun Accuracy Problem

A laboratory test, aimed to check the compliance of the model with demand, indicates that consecutive fires of about 10 centers around a circular region with a radius of 10cm. The fact that the fires, though performed at the same conditions, do not target at the same point is called focusing uncertainty of the handgun. Furthermore, it is observed, that bullet velocity measured 10 meters from gun varies up to about 7m/s (around 340m/s) among the firing set of 10. There are about ten different models and each model seems to display a different magnitude of uncertainty and velocity deviation from the expected average. The company, being willing to produce more data at request, asks to see if the focusing uncertainty and variation in bullet velocities can somehow be correlated. And with some help from other disciplines, the fact behind such uncertainties? Experiment apparatus or manufacturing process. If latter, which manufacturing unit contributes more

The impact of technology on the Ross University Library

Ross University School of Veterinary Medicine (RUSVM) is located in the Eastern Caribbean on the island of St. Kitts. Our mission is the delivery of excellent veterinary education and this was expanded to include research in 2005. The RUSVM Department of Information Services (DIS) - (Library & Learning Resource Center (LRC)) and the Department of Information Technology, work closely in facilitating access of information to its clients. This service is vital to the expansion. The DIS is unique due to its geographical location, focusing on providing timely information; assisting faculty and students in optimal use of the technology available, and has all information accessible online

The impact of propagation uncertainties on the potential Dark Matter contribution to the Fermi LAT mid-latitude gamma-ray data

We investigate the extent to which the uncertainties associated with the propagation of Galactic cosmic rays impact upon estimates for the gamma-ray flux from the mid-latitude region. We consider contributions from both standard astrophysical background (SAB) processes as well as resolved point sources. We have found that the uncertainties in the total gamma-ray flux from the mid-latitude region relating to propagation parameter values consistent with local B/C and Be10/Be9 data dominate by 1-2 orders of magnitude. These uncertainties are reduced to less than an order of magnitude when the normalisations of the SAB spectral components are fitted to the corresponding Fermi LAT data. We have found that for many propagation parameter configurations (PPCs) our fits improve when an extragalactic background (EGB) component is simultaneously fitted to the data. We also investigate the improvement in our fits when a flux contribution from neutralino dark matter (DM), described by the Minimal Supersymmetric Standard Model, was simultaneously fitted to the data. We consider three representative cases of neutralino DM for both Burkert and Einasto DM density profiles, in each case simultaneously fitting a boost factor of the DM contribution together with the SAB and EGB components. We have found that for several PPCs there are significant improvements in our fits, yielding both substantial EGB and DM components, where for a few of these PPCs the best-fit EGB component is consistent with recent estimates by the Fermi Collaboration.Comment: V2: 25 pages, 9 figures and 13 tables. Replaced to match version accepted for publication in PRD. Major revisions to address referee's comment

Accounting for the Unresolved X-ray Background with Sterile Neutrino Dark Matter

We consider a scenario where keV sterile neutrinos constitute all of the currently inferred dark matter abundance, whose radiative decays could potentially account for the flux contributions to the X-ray background attributed to unresolved sources. Here we apply integrated flux methods to results from the observations of the North and South Chandra deep fields in order to deduce constraints on the sterile neutrino mass-mixing parameters.Comment: To be published in the conference proceedings for the ''13th International Symposium on Particles, Strings and Cosmology'' (PASCOS-07), by the American Institute of Physics (AIP

The contemporary landscape of occupational bladder cancer within the United Kingdom: a meta-analysis of risks over the last 80 years.

OBJECTIVE: To profile the contemporary risks of occupational bladder in the UK, as this is a common malignancy that arises through occupational carcinogen exposure. MATERIALS AND METHODS: A systematic review using PubMed, Medline, Embase and Web of Science was performed in March 2016. We selected reports of British workers in which bladder cancer or occupation were the main focus, with sufficient cases or with confidence intervals (CIs). We used the most recent data in populations with multiple reports. We combined odds ratios and risk ratios (RRs) to provide pooled RRs of incidence and disease-specific mortality (DSM). We tested for heterogeneity and publication bias. We extracted bladder cancer mortality from Office of National Statistics death certificates. We compered across regions and with our meta-analysis. RESULTS: We identified 25 articles reporting risks in 702 941 persons. Meta-analysis revealed significantly increased incidence for 12/37 and DSM for five of 37 occupational classes. Three classes had reduced bladder cancer risks. The greatest risk of bladder cancer incidence occurred in chemical process (RR 1.87, 95% CI 1.50-2.34), rubber (RR 1.82, 95% CI 1.4-2.38), and dye workers (RR 1.8, 95% CI 1.07-3.04). The greatest risk of DSM occurred in electrical (RR 1.49, 95% CI 1.19-1.87) and chemical process workers (RR 1.35, 95% CI 1.09-1.68). Bladder cancer mortality was higher in the North of England, probably reflecting smoking patterns and certain industries. Limitations include the lack of sufficient robust data, missing occupational tasks, and no adjustment for smoking. CONCLUSION: Occupational bladder cancer occurs in many workplaces and the risks for incidence and DSM may differ. Regional differences may reflect changes in industry and smoking patterns. Relatively little is known about bladder cancer within British industry, suggesting official data underestimate the disease

Compact Modeling for a Double Gate MOSFET

MOSFETs (metal-oxide-silicon field-effect transistors) are an integral part of modern electronics. Improved designs are currently under investigation, and one that is promising is the double gate MOSFET. Understanding device characteristics is critical for the design of MOSFETs as part of design tools for integrated circuits such as SPICE. Current methods involve the numerical solution of PDEs governing electron transport. Numerical solutions are accurate, but do not provide an appropriate way to optimize the design of the device, nor are they suitable for use in chip simulation software such as SPICE. As chips contain more and more transistors, this problem will get more and more acute. There is hence a need for analytic solutions of the equations governing the performance of MOSFETs, even if these are approximate. Almost all solutions in the literature treat the long-channel case (thin devices) for which the PDEs reduce to ODEs. The goal of this problem is to produce analytical solutions based on the underlying PDEs that are rapid to compute (e.g. require solving only a small number of algebraic equations rather than systems of PDEs). Guided by asymptotic analysis, a fast numerical procedure has been developed to obtain approximate solutions of the governing PDEs governing MOSFET properties, namely electron density, Fermi potential and electrostatic potential. The approach depends on the channel’s being long enough, and appears accurate in this limit