Classifying the secondary component of the binary star W Aquilae

AIMS: The object W Aql is an asymptotic giant branch (AGB) star with a faint companion. By determining more carefully the properties of the companion, we hope to better constrain the properties of the AGB star. METHODS: We present new spectral observations of the binary star W Aql at minimum and maximum brightness and new photometric observations of W Aql at minimum brightness. RESULTS: The composite spectrum near minimum light is predominantly from the companion at wavelengths $\lambda$ < 6000 $\AA$. This spectrum can be classified as F8 to G0, and the brightness of the companion is that of a dwarf star. Therefore, it can be concluded that the companion is a main sequence star. From this, we are able to constrain the mass of the AGB component to 1.04 - 3 $M_\odot$ and the mass of the W Aql system to 2.1 - 4.1 $M_\odot$ . Our photometric results are broadly consistent with this classification and suggest that the main sequence component suffers from approximately 2 mag of extinction in the V band primarily due to the dust surrounding the AGB component.Comment: 5 pages, 1 figure, research not

A new nickel-base wrought superalloy for applications up to 1033 K (1400 F)

Alloy was melted from high purity raw materials and cast ingots extruded at 1422 K. Material was hot rolled to 0.013 m diameter bar stock. Partial solution heat-treatment followed by aging produced structure of fine gamma prime precipitate reinforcing gamma matrix containing coarser blocky gamma prime particles. Alloy can be processed by powder metallurgy

Apparatus for measuring thermal conductivity Patent

Development of apparatus for measuring thermal conductivit

Structure, bonding and morphology of hydrothermally synthesised xonotlite

The authors have systematically investigated the role of synthesis conditions upon the structure and morphology of xonotlite. Starting with a mechanochemically prepared, semicrystalline phase with Ca/Si=1, the authors have prepared a series of xonotlite samples hydrothermally, at temperatures between 200 and 250 degrees C. Analysis in each case was by X-ray photoelectron spectroscopy, environmental scanning electron microscopy and X-ray diffraction. The authors’ use of a much lower water/solid ratio has indirectly confirmed the ‘through solution’ mechanism of xonotlite formation, where silicate dissolution is a key precursor of xonotlite formation. Concerning the role of temperature, too low a temperature (~200 degrees C) fails to yield xonotlite or leads to increased number of structural defects in the silicate chains of xonotlite and too high a temperature (>250 degrees C) leads to degradation of the xonotlite structure, through leaching of interchain calcium. Synthesis duration meanwhile leads to increased silicate polymerisation due to diminishing of the defects in the silicate chains and more perfect crystal morphologies

Age-related changes to lumbosacral spinal cord motoneurons that modulate bladder and bowel functions in male C57BL/6 mice

Incontinence and sexual dysfunction are often increased in the aged human population. In rats and mice the pattern of micturition and faecal clearance also changes with ageing and is suggestive of bladder and bowel dysfunction

New nickel-base wrought superalloy with applications up to 1253 K (1800 F)

Alloy possesses combination of high tensile strength at low and intermediate temperatures to 1033 K with good rupture strength at high temperatures to 1255 K. Alloy has promise for turbine disk application in future gas turbine engines and for wrought integrally bladed turbine wheel; thickness and weight of disk portion of wheel could be reduced

Effects of low level military training flights on wading bird colonies in Florida

During 1983 and 1984 the effect of low level military training flights on the establishment. size and reproductive success of wading bird colonies was studied in Florida. Based on the indirect evidence of colony distributions and turnover rates in relation to military areas (training routes designated to 500 feet or less above ground level and military operations areas). there was no demonstrated effect of military activity on wading bird colony establishment or size on a statewide basis. Colony distributions were random with respect to military areas and turnover rates were within 2% when military and non-military areas were compared. Colony distributions and turnover rates, however. were related to the amount and type.Les tuer-tne or freshwater) of wetland. respectively. During two breeding seasons the behavioral responses and reproductive success of selected species were monitored in a non-habituated treatment colony (military overflights) and a control colony (no overflights). Breeding wading birds responded to F-16 overflights at 420 knots indicated airspeed. 82-84% maximum rpm. 500 feet above ground level and sound levels ranging from 55-100 dBA by exhibiting no response. looking up or changing position (usually to an alert posture): no productivity limiting responses were observed. High-nesting Great Egrets responded more than other species, nestling Great Egrets and Cattle Egrets responded significantly (r <.05) more intensely than adults of their respective species, and adults responded less during incubation and late chick-rearing than at other times. In addition, no differences in adult attendance, aggressive interactions or chick feeding rates were observed to result from F-16 overflights. No evidence of habituation to overflights was noted. Humans entering the colony or airboats approaching the colony vicinity elicited the most severe responses (flushing and panic flights) observed at both sites. Since relatively little coastal military activity occurs at low levels ( ~500 ft) and only one Brown Pelican colony (5-6% of the breeding population) was located in such an area, the reproductive success of five, more lIexposedll study species (Great Egrets, Snowy Egrets, Tricolored Herons, Little Blue Herons, Cattle Egrets) nesting in interior freshwater colonies was studied. Reproductive activity including such factors as nest success, nestling survival, nestling mortality, and nesting chronology was independent of F-16 overflights but related to ecological factors including colony location, colony characteristics and climatology. The responses to and effects of F-16 overflights, as reported here, should not be considered representative of military aircraft at lower altitudes or greater noise levels. (194 pages

Metal Cooling in Simulations of Cosmic Structure Formation

The addition of metals to any gas can significantly alter its evolution by increasing the rate of radiative cooling. In star-forming environments, enhanced cooling can potentially lead to fragmentation and the formation of low-mass stars, where metal-free gas-clouds have been shown not to fragment. Adding metal cooling to numerical simulations has traditionally required a choice between speed and accuracy. We introduce a method that uses the sophisticated chemical network of the photoionization software, Cloudy, to include radiative cooling from a complete set of metals up to atomic number 30 (Zn) that can be used with large-scale three-dimensional hydrodynamic simulations. Our method is valid over an extremely large temperature range (10 K < T < 10^8 K), up to hydrogen number densities of 10^12 cm^-3. At this density, a sphere of 1 Msun has a radius of roughly 40 AU. We implement our method in the adaptive mesh refinement (AMR) hydrodynamic/N-body code, Enzo. Using cooling rates generated with this method, we study the physical conditions that led to the transition from Population III to Population II star formation. While C, O, Fe, and Si have been previously shown to make the strongest contribution to the cooling in low-metallicity gas, we find that up to 40% of the metal cooling comes from fine-structure emission by S, when solar abundance patterns are present. At metallicities, Z > 10^-4 Zsun, regions of density and temperature exist where gas is both thermally unstable and has a cooling time less than its dynamical time. We identify these doubly unstable regions as the most inducive to fragmentation. At high redshifts, the CMB inhibits efficient cooling at low temperatures and, thus, reduces the size of the doubly unstable regions, making fragmentation more difficult.Comment: 19 pages, 12 figures, significant revision, including new figure