Development of design allowable data for Celion 6000/LARC-160, graphite/polyimide composite laminates

A design allowables test program was conducted on Celion 6000/LARC-160 graphite polyimide composite to establish material performance over a 116 K (-250 F) to 589 K (600 F) temperature range. Tension, compression, in-plane shear and short beam shear properties were determined for uniaxial, quasi-isotropic and + or - 45 deg laminates. Effects of thermal aging and moisture saturation on mechanical properties were also evaluated. Celion 6000/LARC-160 graphite/polyimide can be considered an acceptable material system for structural applications to 589 K (600 F)

X-ray Light Curves and Accretion Disk Structure of EX Hydrae

We present X-ray light curves for the cataclysmic variable EX Hydrae obtained with the Chandra High Energy Transmission Grating Spectrometer and the Extreme Ultraviolet Explorer Deep Survey photometer. We confirm earlier results on the shape and amplitude of the binary light curve and discuss a new feature: the phase of the minimum in the binary light curve, associated with absorption by the bulge on the accretion disk, increases with wavelength. We discuss several scenarios that could account for this trend and conclude that, most likely, the ionization state of the bulge gas is not constant, but rather decreases with binary phase. We also conclude that photoionization of the bulge by radiation originating from the white dwarf is not the main source of ionization, but that it is heated by shocks originating from the interaction between the inflowing material from the companion and the accretion disk. The findings in this paper provide a strong test for accretion disk models in close binary systems.Comment: 19 pages, 4 figures, accepted for publication in the Ap

Chionactis occipitalis

Number of Pages: 12Integrative BiologyGeological Science

Chionactis palarostris

Number of Pages: 5Integrative BiologyGeological Science

Adult-child relations in neoliberal times: insights from a dialogue across childhood and parenting culture studies

In this introductory article for the special issue ‘Childhood, Parenting Culture and Adult-Child Relations in Global Perspectives’, we provide an overview of our fields of study (childhood studies and parenting culture studies) by placing them in dialogue. We do so as a basis for drawing out themes emerging from the special issue, in order to explore potential synergies and open broader debates. We begin by tracing moves towards more relational approaches in the social sciences indicating their epistemological and methodological implications. Relational thinking provides a basis for countering antagonistic positionings of children and adults, allowing for circulations of childhood and parenting cultures to be interrogated in relation to new and enduring forms of inequity and changing state-family-capital relations. We suggest that this complicates existing conceptualisations of neoliberalisation while drawing attention to the need for further interrogation of the transnational nature of adult-child relations

Copycatting: Fiscal Policies of States and Their Neighbors

This paper formalizes and tests the notion that state governments' expenditures depend on the spending of similarly situated states. We find that even after allowing for fixed state effects, year effects, and common random effects between neighbors, as state government's level of per capita expenditure is positively and significantly affected by the expenditure levels of its neighbors. Ceteris paribus, a one dollar increase in a state's neighbors' expenditures increases its own expenditure by over 70 cents.

Energy and momentum of cylindrical gravitational waves. II

Recently Nathan Rosen and the present author obtained the energy and momentum densities of cylindrical gravitational waves in Einstein's prescription and found them to be finite and reasonable. In the present paper we calculate the same in prescriptions of Tolman as well as Landau and Lifshitz and discuss the results.Comment: 8 pages, LaTex, To appear in Pramana- J. Physic

ORFEUS II and IUE Spectroscopy of EX Hydrae

Using ORFEUS-SPAS II FUV spectra, IUE UV spectra, and archival EUVE deep survey photometry, we present a detailed picture of the behavior of the magnetic cataclysmic variable EX Hydrae. Like HUT spectra of this source, the FUV and UV spectra reveal broad emission lines of He II, C II-IV, N III and V, O VI, Si III-IV, and Al III superposed on a continuum which is blue in the UV and nearly flat in the FUV. Like ORFEUS spectra of AM Her, the O VI doublet is resolved into broad and narrow emission components. Consistent with its behavior in the optical, the FUV and UV continuum flux densities, the FUV and UV broad emission line fluxes, and the radial velocity of the O VI broad emission component all vary on the spin phase of the white dwarf, with the maximum of the FUV and UV continuum and broad emission line flux light curves coincident with maximum blueshift of the broad O VI emission component. On the binary phase, the broad dip in the EUV light curve is accompanied by strong eclipses of the UV emission lines and by variations in both the flux and radial velocity of the O VI narrow emission component. The available data are consistent with the accretion funnel being the source of the FUV and UV continuum and the O VI broad emission component, and the white dwarf being the source of the O VI narrow emission component.Comment: 21 pages, 10 Postscript figures; LaTeX format, uses aaspp4.sty; table2.tex included separately because it must be printed sideways - see instructions in the file; accepted on 1999 Feb 20 for publication in The Astrophysical Journa