We present new limits on ultra-high energy neutrino fluxes above 10 17 eV based on data collected by the Radio Ice Cherenkov Experiment (RICE) at the South Pole from 1999-2005. We discuss estimation of backgrounds, calibration and data analysis algorithms (both on-line and off-line), procedures used for the dedicated neutrino search, and refinements in our Monte Carlo (MC) simulation, including recent in situ measurements of the complex ice dielectric constant. An enlarged data set and a more detailed study of hadronic showers results in a sensitivity improvement of more than one order of magnitude compared to our previously published results. Examination of the full RICE data set yields zero acceptable neutrino candidates, resulting in 95% confidence-level model dependent limits on the flux E 2 ν dφ/dE ν < 10 −6 GeV/(cm 2 s sr) in the energy range 10 17 < E ν < 10 20 eV. The new RICE results rule out the most intense flux model projections at 95% confidence level.

This article summarizes published journal articles on planetary and epicyclic gear dynamics and vibration. Research in this field has increased dramatically over the past two decades. The wide range of research topics demonstrates the technical challenges of understanding and predicting planetary gear dynamics and vibration. The research in this review includes mathematical models, vibration mode properties, dynamic response predictions including nonlinearities and time-varying mesh stiffness fluctuations, the effects of elastic compliance, and gyroscopic effects, among other topics. Practical aspects are also included, for example, planet load sharing, planet phasing, tooth surface modifications, and characteristics of measured vibration response.

This work compares spur gear tooth mesh stiffness calculations using two approaches. The first is a common approach from the literature that calculates the mesh stiffness by dividing the mesh force by the mesh deflection, which we call the average slope method. The second approach calculates the local slope of the force-deflection curve about a nominal deflection. The two approaches result in meaningfully different mesh stiffness predictions that persist for wide ranges of applied torque and for gear teeth with tooth surface modifications. It is shown that each calculation approach has its own distinct use, broadly divided as average slope mesh stiffness for static analyses and local slope for dynamic analyses. Furthermore, the two stiffness calculation approaches lead to different vibration models. This means for vibration analyses the choice is not solely which of the two stiffnesses to use but also how to implement that stiffness appropriately in a model. Even though the mesh stiffnesses in this work are calculated using a finite element/contact mechanics approach, the findings are equally valid for mesh stiffnesses obtained from conventional finite element methods, analytical models, and experiments.

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This study investigates the modal property structure of high-speed planetary gears with gyroscopic effects. The vibration modes of these systems are complex-valued and speed-dependent. Equally-spaced and diametrically-opposed planet spacing are considered. Three mode types exist, and these are classified as planet, rotational, and translational modes. The properties of each mode type and that these three types are the only possible types are mathematically proven. Reduced eigenvalue problems are determined for each mode type. The eigenvalues for an example high-speed planetary gear are determined over a wide range of carrier speeds. Divergence and flutter instabilities are observed at extremely high speeds.