Euler Technology Assessment for Preliminary Aircraft Design: Compressibility Predictions by Employing the Cartesian Unstructured Grid SPLITFLOW Code

The objective of the second phase of the Euler Technology Assessment program was to evaluate the ability of Euler computational fluid dynamics codes to predict compressible flow effects over a generic fighter wind tunnel model. This portion of the study was conducted by Lockheed Martin Tactical Aircraft Systems, using an in-house Cartesian-grid code called SPLITFLOW. The Cartesian grid technique offers several advantages, including ease of volume grid generation and reduced number of cells compared to other grid schemes. SPLITFLOW also includes grid adaption of the volume grid during the solution to resolve high-gradient regions. The SPLITFLOW code predictions of configuration forces and moments are shown to be adequate for preliminary design, including predictions of sideslip effects and the effects of geometry variations at low and high angles-of-attack. The transonic pressure prediction capabilities of SPLITFLOW are shown to be improved over subsonic comparisons. The time required to generate the results from initial surface data is on the order of several hours, including grid generation, which is compatible with the needs of the design environment

Evidence for a very slow X-ray pulsar in 2S0114+650 from RXTE All-Sky Monitor Observations

Rossi X-ray Timing Explorer (RXTE) All-Sky Monitor (ASM) observations of the X-ray binary 2S0114+650 show modulations at periods close to both the optically derived orbital period (11.591 days) and proposed pulse period (~ 2.7 hr). The pulse period shows frequency and intensity variability during the more than 2 years of ASM observations analyzed. The pulse properties are consistent with this arising from accretion onto a rotating neutron star and this would be the slowest such period known. The shape of the orbital light curve shows modulation over the course of the entire orbit and a comparison is made with the orbital light curve of Vela X-1. However, the expected phase of eclipse, based on an extrapolation of the optical ephemeris, does not correspond with the observed orbital minimum. The orbital period derived from the ASM light curve is also slightly longer than the optical period.Comment: To be published in the Astrophysical Journal, 1999, volume 511. 9 figure

Solutions of the sDiff(2)Toda equation with SU(2) Symmetry

We present the general solution to the Plebanski equation for an H-space that admits Killing vectors for an entire SU(2) of symmetries, which is therefore also the general solution of the sDiff(2)Toda equation that allows these symmetries. Desiring these solutions as a bridge toward the future for yet more general solutions of the sDiff(2)Toda equation, we generalize the earlier work of Olivier, on the Atiyah-Hitchin metric, and re-formulate work of Babich and Korotkin, and Tod, on the Bianchi IX approach to a metric with an SU(2) of symmetries. We also give careful delineations of the conformal transformations required to ensure that a metric of Bianchi IX type has zero Ricci tensor, so that it is a self-dual, vacuum solution of the complex-valued version of Einstein's equations, as appropriate for the original Plebanski equation.Comment: 27 page

Finite Euler Hierarchies And Integrable Universal Equations

Recent work on Euler hierarchies of field theory Lagrangians iteratively constructed {}from their successive equations of motion is briefly reviewed. On the one hand, a certain triality structure is described, relating arbitrary field theories, {\it classical\ts} topological field theories -- whose classical solutions span topological classes of manifolds -- and reparametrisation invariant theories -- generalising ordinary string and membrane theories. On the other hand, {\it finite} Euler hierarchies are constructed for all three classes of theories. These hierarchies terminate with {\it universal\ts} equations of motion, probably defining new integrable systems as they admit an infinity of Lagrangians. Speculations as to the possible relevance of these theories to quantum gravity are also suggested.Comment: (replaces previous unprintable version corrupted mailer) 13 p., (Plain TeX), DTP-92/3

Possible Signatures of a Cold-Flow Disk from MUSE using a z=1 galaxy--quasar pair towards SDSSJ1422-0001

We use a background quasar to detect the presence of circum-galactic gas around a $z=0.91$ low-mass star forming galaxy. Data from the new Multi Unit Spectroscopic Explorer (MUSE) on the VLT show that the host galaxy has a dust-corrected star-formation rate (SFR) of 4.7$\pm$0.2 Msun/yr, with no companion down to 0.22 Msun/yr (5 $\sigma$) within 240 kpc (30"). Using a high-resolution spectrum (UVES) of the background quasar, which is fortuitously aligned with the galaxy major axis (with an azimuth angle $\alpha$ of only $15^\circ$), we find, in the gas kinematics traced by low-ionization lines, distinct signatures consistent with those expected for a "cold flow disk" extending at least 12 kpc ($3\times R_{1/2}$). We estimate the mass accretion rate $\dot M_{\rm in}$ to be at least two to three times larger than the SFR, using the geometric constraints from the IFU data and the HI column density of $\log N_{\rm HI} \simeq 20.4$ obtained from a {\it HST}/COS NUV spectrum. From a detailed analysis of the low-ionization lines (e.g. ZnII, CrII, TiII, MnII, SiII), the accreting material appears to be enriched to about 0.4 $Z_\odot$ (albeit with large uncertainties: $\log Z/Z_\odot=-0.4~\pm~0.4$), which is comparable to the galaxy metallicity ($12+\log \rm O/H=8.7\pm0.2$), implying a large recycling fraction from past outflows. Blue-shifted MgII and FeII absorptions in the galaxy spectrum from the MUSE data reveal the presence of an outflow. The MgII and FeII doublet ratios indicate emission infilling due to scattering processes, but the MUSE data do not show any signs of fluorescent FeII* emission.Comment: 17 pages, 11 figures, in press (ApJ), minor edits after the proofs. Data available at http://muse-vlt.eu/science/j1422

The dispersive self-dual Einstein equations and the Toda lattice

The Boyer-Finley equation, or $SU(\infty)$-Toda equation is both a reduction of the self-dual Einstein equations and the dispersionlesslimit of the $2d$-Toda lattice equation. This suggests that there should be a dispersive version of the self-dual Einstein equation which both contains the Toda lattice equation and whose dispersionless limit is the familiar self-dual Einstein equation. Such a system is studied in this paper. The results are achieved by using a deformation, based on an associative $\star$-product, of the algebra $sdiff(\Sigma^2)$ used in the study of the undeformed, or dispersionless, equations.Comment: 11 pages, LaTeX. To appear: J. Phys.

Determining the Physical Properties of the B Stars I. Methodology and First Results

We describe a new approach to fitting the UV-to-optical spectra of B stars to model atmospheres and present initial results. Using a sample of lightly reddened stars, we demonstrate that the Kurucz model atmospheres can produce excellent fits to either combined low dispersion IUE and optical photometry or HST FOS spectrophotometry, as long as the following conditions are fulfilled: 1) an extended grid of Kurucz models is employed, 2) the IUE NEWSIPS data are placed on the FOS absolute flux system using the Massa & Fitzpatrick (1999) transformation, and 3) all of the model parameters and the effects of interstellar extinction are solved for simultaneously. When these steps are taken, the temperatures, gravities, abundances and microturbulence velocities of lightly reddened B0-A0 V stars are determined to high precision. We also demonstrate that the same procedure can be used to fit the energy distributions of stars which are reddened by any UV extinction curve which can be expressed by the Fitzpatrick & Massa (1990) parameterization scheme. We present an initial set of results and verify our approach through comparisons with angular diameter measurements and the parameters derived for an eclipsing B star binary. We demonstrate that the metallicity derived from the ATLAS 9 fits to main sequence B stars is essentially the Fe abundance. We find that a near zero microturbulence velocity provides the best-fit to all but the hottest or most luminous stars (where it may become a surrogate for atmospheric expansion), and that the use of white dwarfs to calibrate UV spectrophotometry is valid.Comment: 17 pages, including 2 pages of Tables and 6 pages of Figures. Astrophysical Jounral, in pres

A cadaveric case study on metastatic breast cancer pathology

INTRODUCTION: Breast cancer is the second most common cancer among women in the United States. The exact etiology of breast cancer is unknown, but over 70% of breast cancer cases involve only two risk factors: being a woman and being over the age of 50. Women with a family history of breast cancer, as well as women who experience early menopause, have an even greater risk of developing this disease. When considering racial demographics, African-American women have a 4-8% lower incidence rate of breast cancer than Caucasian women but are 40% more likely to die from the disease. Breast cancer commonly metastasizes to the bone, skin, lungs, and liver. Liver metastasis occurs in about 40-50% of women with metastatic breast cancer, but less than 1% of these cases progress to hepatic failure. OBJECTIVES: The overall purpose of this study was to evaluate the pathology associated with the patient’s cause of death: malignant neoplasm of the right breast, pleural effusion, ascites, and acute kidney injury. The secondary aims of this study were to determine the stage of breast cancer and analyze the distribution of various metastatic infiltrations throughout the body, specifically in the liver, abdominal cavity, and superficial cutaneous layers. METHODS: This is a case report from one of the cadavers in the Gross Anatomy laboratory at the Philadelphia College of Osteopathic Medicine, South Georgia campus. Samples from the patient’s breasts, liver, and skin will be sent to the Colquitt Regional Medical Center laboratory for histopathological processing. CONCLUSION: Upon receiving histopathological results, we will analyze the malignancy status and further evaluate associated pathological findings. These results will be used to widen the breadth of knowledge surrounding breast cancer in hopes of improving care and patient outcomes