Horava-Lifshitz gravity: tighter constraints for the Kehagias-Sfetsos solution from new solar system data

We analytically work out the perturbation induced by the Kehagias-Sfetsos (KS) space-time solution of the Horava-Lifshitz (HL) modified gravity at long distances on the two-body range for a pair of test particles A and B orbiting the same mass M. We apply our results to the most recently obtained range-residuals \delta\rho for some planets of the solar system (Mercury, Mars, Saturn) ranged from the Earth to effectively constrain the dimensionsless KS parameter \psi_0 for the Sun. We obtain \psi_0 >= 7.2 x 10^-10 (Mercury), \psi_0 >= 9 x 10^-12 (Mars), \psi_0 >= 1.7 x 10^-12 (Saturn). Such lower bounds are tighter than other ones existing in literature by several orders of magnitude. We also preliminarily obtain \psi_0 >= 8 x 10^-10 for the system constituted by the S2 star orbiting the Supermassive Black Hole (SBH) in the center of the Galaxy.Comment: LaTex2e, 15 pages, 1 table, 3 figures, 31 references. Version matching the one at press in International Journal of Modern Physics D (IJMPD

Three-dimensional viscous flow analysis inside a turbine volute

A three-dimensional numerical method has been developed to analyze the complex flow field inside a turbine volute. Comparisons are made between solutions with different boundary conditions

Secondary Electron Yield Measurements of Fermilab's Main Injector Vacuum Vessel

We discuss the progress made on a new installation in Fermilab's Main Injector that will help investigate the electron cloud phenomenon by making direct measurements of the secondary electron yield (SEY) of samples irradiated in the accelerator. In the Project X upgrade the Main Injector will have its beam intensity increased by a factor of three compared to current operations. This may result in the beam being subject to instabilities from the electron cloud. Measured SEY values can be used to further constrain simulations and aid our extrapolation to Project X intensities. The SEY test-stand, developed in conjunction with Cornell and SLAC, is capable of measuring the SEY from samples using an incident electron beam when the samples are biased at different voltages. We present the design and manufacture of the test-stand and the results of initial laboratory tests on samples prior to installation.Comment: 3 pp. 3rd International Particle Accelerator Conference (IPAC 2012) 20-25 May 2012, New Orleans, Louisian

Three-Dimensional Flow Analysis Inside Consortium Impeller at Design and Off-Design Conditions

Three-dimensional flow fields inside the Consortium impeller were analyzed with a Navier-Stokes code. The numerical results at the design and off-design conditions are compared with the experimental data

Mortality following Traumatic Brain Injury among Individuals Unable to Follow Commands at the Time of Rehabilitation Admission: A National Institute on Disability and Rehabilitation Research Traumatic Brain Injury Model Systems Study

Severe traumatic brain injury (TBI) has been associated with increased mortality. This study characterizes long-term mortality, life expectancy, causes of death, and risk factors for death among patients admitted within the National Institute on Disability and Rehabilitation Research (NIDRR) TBI Model Systems Programs (TBIMS) who lack command following at the time of admission for inpatient TBI rehabilitation. Of the 8084 persons enrolled from 1988 and 2009, 387 from 20 centers met study criteria. Individuals with moderate to severe TBI who received inpatient rehabilitation were 2.2 times more likely to die than individuals in the U.S. general population of similar age, gender, and race, with an average life expectancy (LE) reduction of 6.6 years. The subset of individuals who were unable to follow commands on admission to rehabilitation was 6.9 times more likely to die, with an average LE reduction of 12.2 years. Relative to the U.S. general population matched for age, gender, and race/ethnicity, these non–command following individuals were more than four times more likely to die of circulatory conditions, 44 times more likely to die of pneumonia, and 38 times more likely to die of aspiration pneumonia. The subset of individuals with TBI who are unable to follow commands upon admission to inpatient rehabilitation are at a significantly increased risk of death when compared with the U.S. general population and compared with all individuals with moderate to severe TBI receiving inpatient rehabilitation. Respiratory causes of death predominate, compared with the general population

When Models Interact with their Subjects: The Dynamics of Model Aware Systems

A scientific model need not be a passive and static descriptor of its subject. If the subject is affected by the model, the model must be updated to explain its affected subject. In this study, two models regarding the dynamics of model aware systems are presented. The first explores the behavior of "prediction seeking" (PSP) and "prediction avoiding" (PAP) populations under the influence of a model that describes them. The second explores the publishing behavior of a group of experimentalists coupled to a model by means of confirmation bias. It is found that model aware systems can exhibit convergent random or oscillatory behavior and display universal 1/f noise. A numerical simulation of the physical experimentalists is compared with actual publications of neutron life time and {\Lambda} mass measurements and is in good quantitative agreement.Comment: Accepted for publication in PLoS-ON

Validation in Fusion Research: Towards Guidelines and Best Practices

Because experiment/model comparisons in magnetic confinement fusion have not yet satisfied the requirements for validation as understood broadly, a set of approaches to validating mathematical models and numerical algorithms are recommended as good practices. Previously identified procedures, such as verification, qualification, and analysis of error and uncertainty, remain important. However, particular challenges intrinsic to fusion plasmas and physical measurement therein lead to identification of new or less familiar concepts that are also critical in validation. These include the primacy hierarchy, which tracks the integration of measurable quantities, and sensitivity analysis, which assesses how model output is apportioned to different sources of variation. The use of validation metrics for individual measurements is extended to multiple measurements, with provisions for the primacy hierarchy and sensitivity. This composite validation metric is essential for quantitatively evaluating comparisons with experiments. To mount successful and credible validation in magnetic fusion, a new culture of validation is envisaged.Comment: 27 pages, 1 table, 6 figure