Supersonic Flow of Chemically Reacting Gas-Particle Mixtures. Volume 2: RAMP - A Computer Code for Analysis of Chemically Reacting Gas-Particle Flows

A computer program written in conjunction with the numerical solution of the flow of chemically reacting gas-particle mixtures was documented. The solution to the set of governing equations was obtained by utilizing the method of characteristics. The equations cast in characteristic form were shown to be formally the same for ideal, frozen, chemical equilibrium and chemical non-equilibrium reacting gas mixtures. The characteristic directions for the gas-particle system are found to be the conventional gas Mach lines, the gas streamlines and the particle streamlines. The basic mesh construction for the flow solution is along streamlines and normals to the streamlines for axisymmetric or two-dimensional flow. The analysis gives detailed information of the supersonic flow and provides for a continuous solution of the nozzle and exhaust plume flow fields. Boundary conditions for the flow solution are either the nozzle wall or the exhaust plume boundary

Supersonic flow of chemically reacting gas-particle mixtures. Volume 1: A theoretical analysis and development of the numerical solution

A numerical solution for chemically reacting supersonic gas-particle flows in rocket nozzles and exhaust plumes was described. The gas-particle flow solution is fully coupled in that the effects of particle drag and heat transfer between the gas and particle phases are treated. Gas and particles exchange momentum via the drag exerted on the gas by the particles. Energy is exchanged between the phases via heat transfer (convection and/or radiation). Thermochemistry calculations (chemical equilibrium, frozen or chemical kinetics) were shown to be uncoupled from the flow solution and, as such, can be solved separately. The solution to the set of governing equations is obtained by utilizing the method of characteristics. The equations cast in characteristic form are shown to be formally the same for ideal, frozen, chemical equilibrium and chemical non-equilibrium reacting gas mixtures. The particle distribution is represented in the numerical solution by a finite distribution of particle sizes

Detection of ionized gas in the globular cluster 47 Tucanae

We report the detection of ionized intracluster gas in the globular cluster 47 Tucanae. Pulsars in this cluster with a negative period derivative, which must lie in the distant half of the cluster, have significantly higher measured integrated electron column densities than the pulsars with a positive period derivative. We derive the plasma density within the central few pc of the cluster using two different methods which yield consistent values. Our best estimate of n_e = (0.067+-0.015)/cm^3 is about 100 times the free electron density of the ISM in the vicinity of 47 Tucanae, and the ionized gas is probably the dominant component of the intracluster medium.Comment: 5 pages, 3 included figures, accepted for publication by ApJ Letter

Ecological niche model of Phlebotomus alexandri and P. papatasi (Diptera: Psychodidae) in the Middle East

<p>Abstract</p> <p>Background</p> <p>The purpose of this study is to create distribution models of two sand fly species, <it>Phlebotomus papatasi </it>(Scopoli) and <it>P. alexandri </it>(Sinton), across the Middle East. <it>Phlebotomus alexandri </it>is a vector of visceral leishmaniasis, while <it>P. papatasi </it>is a vector of cutaneous leishmaniasis and sand fly fever. Collection records were obtained from literature reports from 1950 through 2007 and unpublished field collection records. Environmental layers considered in the model were elevation, precipitation, land cover, and WorldClim bioclimatic variables. Models were evaluated using the threshold-independent area under the curve (AUC) receiver operating characteristic analysis and the threshold-dependent minimum training presence.</p> <p>Results</p> <p>For both species, land cover was the most influential environmental layer in model development. The bioclimatic and elevation variables all contributed to model development; however, none influenced the model as strongly as land cover.</p> <p>Conclusion</p> <p>While not perfect representations of the absolute distribution of <it>P. papatasi </it>and <it>P. alexandri</it>, these models indicate areas with a higher probability of presence of these species. This information could be used to help guide future research efforts into the ecology of these species and epidemiology of the pathogens that they transmit.</p

Assessing the Vegetative Diversity of an East Texas Golf Course using Principles of Landscape Ecology

The objectives of this study was to determine the vegetative diversity and the effects of the edge between fairways (introduced patches) and out-of-bounds areas (remnant patches) to determine if such management activities influence plant diversity. This study was conducted at the Pineywoods Country Club in the Pineywoods Region of East Texas near Nacogdoches, TX, USA by assessing the spatial distribution of these matrices and patches and their influence on edge effect composition and structure in the matrix; and, if species diversity and composition differed between these edges and interior of the matrices. Nested plots were placed along transects and canopy cover, percent cover, number of individuals by species, tree density, and percent cover of ground cover materials were analyzed using ordination. Dbh, shrub and herbaceous percent cover, and canopy cover were tested for normality utilizing a Shapiro-Wilk normality test, Wilcoxon-Mann-Whitney was used to analyze edge plots and interior plots, and @RISK goodness-of-fit measures were utilized to identify percent cover data distributions. Statistical differences (0.05 α level) between the edge and interior dbh and shrub datasets and a similarity between the edge and interior datasets of the overstory and herbaceous strata were found. Many of the interior shrub plots had a higher H’ (Shannon-Wiener index) and D (Simpson’s index) than the edge plots. Canopy cover was often over 70%, and herbaceous species abundance was often higher (1-11 species) than that of the shrub stratum (1-3 species). Beta diversity indicated that the remnant patches were diverse ( between 0.19-0.30) within all three strata. Natural and anthropogenic disturbances altered the structure and function of the remnant patches: tree density decreased in edge plots due to management. Canopy cover was high over edge plots; however, light was able to reach the ground at an angle across the fairway. Past and current management practices combined with disturbance events have caused the interior of the remnant patches to be disturbed to the degree that they were not representative of the Pineywoods eco-region. The exceptional drought in 2011 may have influenced these results. It was not determined whether the fairway patches within the forest matrix resulted in edge effects

Australian women's prediagnostic values and influencing sociodemographic variables relating to treatment choices for early breast cancer treatment

Women are often asked by their doctors to choose their preferred treatment for early breast cancer. Evidence shows that many women are distressed and confused about how to make this treatment decision and frequently seek help from nurses. Very little is known about women's value-centred decision-making in relation to selecting treatment for breast cancer and for nurses it is difficult to know how to assist these women with this process. In this study, 377 women participated prior to undergoing routine mammography screening and the data were collected using the Pre-Decision Portfolio Questionnaire (PDPQ) by Pierce 1. The partipants identified that expected treatment outcomes were the most important factor in choosing early breast cancer treatment. The majority reported that it was very important that a treatment would reduce the chances the cancer would return (95.6%), increase the length of their life (82.1%) and lead them to being healthy (80.4%). In addition, the participants indicated that it was important, or very important, that the emotional consequences of the treatment did "not make you depressed" (88.6%) or "sad" (90.4%) and should "keep you from worrying" (97%) and "give you peace of mind" (98.6%). Other factors, such as treatment's side effects, were identified as less important. Age, employment, education and having a family history of breast cancer were found to be significant influencing variables on the values of the participants. It was concluded that assessing and understanding the treatment values of women can help nurses focus on areas of importance to the woman and lead to informed decision-making when they are choosing treatment for early breast cancer

Phase-resolved Crab Studies with a Cryogenic TES Spectrophotometer

We are developing time- and energy-resolved near-IR/optical/UV photon detectors based on sharp superconducting-normal transition edges in thin films. We report observations of the Crab pulsar made during prototype testing at the McDonald 2.7m telescope with a fiber-coupled transition-edge sensor (TES) system. These data show substantial (d[alpha]~0.3), rapid variations in the spectral index through the pulse profile, with a strong phase-varying IR break across our energy band. These variations correlate with X-ray spectral variations, but no single synchrotron population can account for the full Spectral Energy Distribution (SED). We also describe test spectrophotopolarimetry observations probing the energy dependence of the polarization sweep; this may provide a new key to understanding the radiating particle population.Comment: 12 pages, 10 figures -- to appear in ApJ V56

First Arkansas Records for Bigscale Logperch Percina macrolepida Stevenson (Pisces: Percidae), with Comments on Habitat Preference and Distinctive Characters

Fish samples were collected with seines and rotenone from 21 localities representing five major habitat types along the Red River in Arkansas. The bigscale logperch, Percina macrolepida, was found at 11 of those sites, providing the first records ofthat species from the state. The primary preferred habitat parameters for bigscale logperch are no current, a sand and/or silt substrate, and a water depth of 1.0-2.0 m. Percina macrolepida is morphologically very similar to the widespread and common logperch, P. caprodes, but can be distinguished from all forms of that species in Arkansas by a combination of characters. Snout shape and the presence of scales on the breast, prepectoral area, and along the posterior edge of the preopercle in P. macrolepida are the most useful distinguishing features

Transmission Dynamics of Highly Pathogenic Avian Influenza at Lake Constance (Europe) During the Outbreak of Winter 2005-2006

Highly pathogenic avian influenza virus (HPAI) H5N1 poses a serious threat to domestic animals. Despite the large number of studies on influenza A virus in waterbirds, little is still known about the transmission dynamics, including prevalence, behavior, and spread of these viruses in the wild waterbird population. From January to April 2006, the HPAI H5N1 virus was confirmed in 82 dead wild waterbirds at the shores of Lake Constance. In this study, we present simple mathematical models to examine this outbreak and to investigate the transmission dynamics of HPAI in wild waterbirds. The population dynamics model of wintering birds was best represented by a sinusoidal function. This model was considered the most adequate to represent the susceptible compartment of the SIR model. The three transmission models predict a basic reproduction ratio (R 0) with value of approximately 1.6, indicating a small epidemic, which ended with the migration of susceptible wild waterbirds at the end of the winter. With this study, we quantify for the first time the transmission of HPAI H5N1 virus at Lake Constance during the outbreak of winter 2005-2006. It is a step toward the improvement of the knowledge of transmission of the virus among wild waterbird