Jupiter's red spot in 1968 - 1969

Photographic observations of Jupiter Red Spo

Measurements of planetary dimensions

Recent measurements of planetary dimension

Measurements of Saturn in 1969

Photographic measurements of Saturn and its ring

An Annotated Checklist of Scarab Beetles (Coleoptera: Scarabaeidae) from Northeastern Iowa

A survey of scarab beetles (Coleoptera: Scarabaeidae) was conducted during 2009 in the geographically distinct area of Winneshiek and Allamakee counties in extreme Northeast Iowa. Four plant communities distributed among 10 locations, including tallgrass prairie, mixed grassland and forest, oak-hickory forest, and pasture were sampled during 2009 using black light traps, banana- beer traps, rodent burrow pitfalls, manure-baited pitfalls, and gleaning. Additionally, previous specimen records were examined. Forty-nine scarab species were documented for Winneshiek and Allamakee counties, including five species not previously reported in Iowa. Mixed grassland and forest habitat contained the greatest scarab species richness (n=31); black light trapping yielded the greatest number of individual beetles and collected the most species

Statistical distribution of mechanical properties for three graphite-epoxy material systems

Graphite-epoxy composites are playing an increasing role as viable alternative materials in structural applications necessitating thorough investigation into the predictability and reproducibility of their material strength properties. This investigation was concerned with tension, compression, and short beam shear coupon testing of large samples from three different material suppliers to determine their statistical strength behavior. Statistical results indicate that a two Parameter Weibull distribution model provides better overall characterization of material behavior for the graphite-epoxy systems tested than does the standard Normal distribution model that is employed for most design work. While either a Weibull or Normal distribution model provides adequate predictions for average strength values, the Weibull model provides better characterization in the lower tail region where the predictions are of maximum design interest. The two sets of the same material were found to have essentially the same material properties, and indicate that repeatability can be achieved

The structure of hypersonic shock waves using Navier-Stokes equations modified to include mass diffusion

Howard Brenner has recently proposed modifications to the Navier-Stokes equations that relate to a diffusion of fluid volume that would be significant for flows with high density gradients. In a previous paper (Greenshields & Reese, 2007), we found these modifications gave good predictions of the viscous structure of shock waves in argon in the range Mach 1.0-12.0 (while conventional Navier-Stokes equations are known to fail above about Mach 2). However, some areas of concern with this model were a somewhat arbitrary choice of modelling coefficient, and potentially unphysical and unstable solutions. In this paper, we therefore present slightly different modifications to include molecule mass diffusion fully in the Navier-Stokes equations. These modifications are shown to be stable and produce physical solutions to the shock problem of a quality broadly similar to those from the family of extended hydrodynamic models that includes the Burnett equations. The modifications primarily add a diffusion term to the mass conservation equation, so are at least as simple to solve as the Navier-Stokes equations; there are none of the numerical implementation problems of conventional extended hydrodynamics models, particularly in respect of boundary conditions. We recommend further investigation and testing on a number of different benchmark non-equilibrium flow cases.Comment: written for the 2nd European Conference on AeroSpace Sciences (EUCASS), Belgium, 200

A rapidly moving spot on jupiter's north temperate belt

Photographic observations of rapidly moving spot in Jupiter atmospher

Vibration analysis of a circular disc backed by a cylindrical cavity

This paper describes the free vibration analysis of a thin disc vibrating and interacting with an acoustic medium contained in a cylindrical duct. The effects of structural-acoustic coupling are studied by means of an analytical-numerical method that is based upon classical theory and the Galerkin method. The coupling effects are discussed, and results obtained from the analysis are compared with corresponding values obtained both experimentally and from a finite element analysis. There is good agreement between the three sets of results

Review of Conformally Flat Approximation for Binary Neutron Star Initial Conditions

The spatially conformally flat approximation (CFA) is a viable method to deduce initial conditions for the subsequent evolution of binary neutron stars employing the full Einstein equations. Here we review the status of the original formulation of the CFA for the general relativistic hydrodynamic initial conditions of binary neutron stars. We illustrate the stability of the conformally flat condition on the hydrodynamics by numerically evolving ~100 quasi-circular orbits. We illustrate the use of this approximation for orbiting neutron stars in the quasi-circular orbit approximation to demonstrate the equation of state dependence of these initial conditions and how they might affect the emergent gravitational wave frequency as the stars approach the innermost stable circular orbit.Comment: 22 pages, 12 figures, revised as per referee recommendation