Rurality or distance to care and the risk of homelessness among Afghanistan and Iraq veterans

INTRODUCTION: To date, no studies have examined the relationship of rurality and distance to nearest VA facility to risk of homelessness. METHODS: We examined differences in the rate of homelessness within a year of a Veteran's first encounter with the VA following last military separation based on rurality and distance to the nearest VA facility using multivariable log-binomial regressions. RESULTS: In our cohort of 708,120 Veterans, 73% were determined to have a forwarding address in urban areas, 59.2% and 86.7% lived within 40 miles of the nearest VA medical center (VAMC), respectively. Veterans living in a rural area and those living between 20+ miles away from the nearest VAMC were at a lower risk for homelessness. CONCLUSIONS: Our unique dataset allowed us to explore the relationship between geography and homelessness. These results are important to policy makers in understanding the risk factors for homelessness among Veterans and planning interventions

Discovery of an ultramassive pulsating white dwarf

We announce the discovery of the most massive pulsating hydrogen-atmosphere (DA) white dwarf (WD) ever discovered, GD 518. Model atmosphere fits to the optical spectrum of this star show it is a 12,030 +/- 210 K WD with a log(g) = 9.08 +/- 0.06, which corresponds to a mass of 1.20 +/- 0.03 Msun. Stellar evolution models indicate that the progenitor of such a high-mass WD endured a stable carbon-burning phase, producing an oxygen-neon-core WD. The discovery of pulsations in GD 518 thus offers the first opportunity to probe the interior of a WD with a possible oxygen-neon core. Such a massive WD should also be significantly crystallized at this temperature. The star exhibits multi-periodic luminosity variations at timescales ranging from roughly 425-595 s and amplitudes up to 0.7%, consistent in period and amplitude with the observed variability of typical ZZ Ceti stars, which exhibit non-radial g-mode pulsations driven by a hydrogen partial ionization zone. Successfully unraveling both the total mass and core composition of GD 518 provides a unique opportunity to investigate intermediate-mass stellar evolution, and can possibly place an upper limit to the mass of a carbon-oxygen-core WD, which in turn constrains SNe Ia progenitor systems.Comment: 5 pages, 3 figures, Astrophysical Journal Letters, 771, L2 (2013

Discovery of pulsations, including possible pressure modes, in two new extremely low mass, He-core white dwarfs

We report the discovery of the second and third pulsating extremely low mass white dwarfs (WDs), SDSS J111215.82+111745.0 (hereafter J1112) and SDSS J151826.68+065813.2 (hereafter J1518). Both have masses < 0.25 Msun and effective temperatures below 10,000 K, establishing these putatively He-core WDs as a cooler class of pulsating hydrogen-atmosphere WDs (DAVs, or ZZ Ceti stars). The short-period pulsations evidenced in the light curve of J1112 may also represent the first observation of acoustic (p-mode) pulsations in any WD, which provide an exciting opportunity to probe this WD in a complimentary way compared to the long-period g-modes also present. J1112 is a Teff = 9590 +/- 140 K and log(g) = 6.36 +/- 0.06 WD. The star displays sinusoidal variability at five distinct periodicities between 1792-2855 s. In this star we also see short-period variability, strongest at 134.3 s, well short of expected g-modes for such a low-mass WD. The other new pulsating WD, J1518, is a Teff = 9900 +/- 140 K and log(g) = 6.80 +/- 0.05 WD. The light curve of J1518 is highly non-sinusoidal, with at least seven significant periods between 1335-3848 s. Consistent with the expectation that ELM WDs must be formed in binaries, these two new pulsating He-core WDs, in addition to the prototype SDSS J184037.78+642312.3, have close companions. However, the observed variability is inconsistent with tidally induced pulsations and is so far best explained by the same hydrogen partial-ionization driving mechanism at work in classic C/O-core ZZ Ceti stars.Comment: 9 pages, 5 figures, accepted to The Astrophysical Journa

Pruning The ELM Survey: Characterizing Candidate Low-mass White Dwarfs through Photometric Variability

We assess the photometric variability of nine stars with spectroscopic T {sub eff} and log g values from the ELM Survey that locates them near the empirical extremely low-mass (ELM) white dwarf instability strip. We discover three new pulsating stars: SDSS J135512.34+195645.4, SDSS J173521.69+213440.6, and SDSS J213907.42+222708.9. However, these are among the few ELM Survey objects that do not show radial velocity (RV) variations that confirm the binary nature expected of helium-core white dwarfs. The dominant 4.31 hr pulsation in SDSS J135512.34+195645.4 far exceeds the theoretical cut-off for surface reflection in a white dwarf, and this target is likely a high-amplitude δ Scuti pulsator with an overestimated surface gravity. We estimate the probability to be less than 0.0008 that the lack of measured RV variations in four of eight other pulsating candidate ELM white dwarfs could be due to low orbital inclination. Two other targets exhibit variability as photometric binaries. Partial coverage of the 19.342 hr orbit of WD J030818.19+514011.5 reveals deep eclipses that imply a primary radius >0.4 R {sub ⊙}—too large to be consistent with an ELM white dwarf. The only object for which our time series photometry adds support to ELM white dwarf classification is SDSS J105435.78−212155.9,more » which has consistent signatures of Doppler beaming and ellipsoidal variations. We conclude that the ELM Survey contains multiple false positives from another stellar population at T {sub eff}≲9000 K, possibly related to the sdA stars recently reported from SDSS spectra.« les

The Ursinus Weekly, January 14, 1957

McClure releases statement on new funds for UC • UC evaluation to be held in Feb. • Committee begins work on Campus Chest plans • Y to hear speaker Wed. • WSGA plans forum on student government • Frosh to present Show boat on January 18 • Canterbury Club hears Busler, plans Communion • Two brothers of APE announce engagements • Two Deltas engaged New Year\u27s to Ursinus women • Symons accepts state post in administrative dept. • Twelve Ursinus seniors to be included in 1957 Who\u27s who • Washington trip planned by WRC • MSGA council discusses plans for second semester • Chi Alpha to hear views on evangelism tonight • KDK drive yields 300 lbs. of clothing for Hungary • Two Sig Rho-ers pinned • Reese - Ruth engagement • Noted showman to talk at Feb. Forum • Editorial: Some comments on culture • Da Nighta afta Chrismist • Letters to the editor • Love conquereth all • American theatre: Sophistication or drama • Drexel, Delaware hand J.V. cagers first two defeats • Badminton belles begin practice • Bailey gains new post in E.C.A.C. • Heavyweight forfeit gives Fords 18-18 tie with Bruin matmen Sat. • Losing streak goes to 7 as cagers lose to Drexel, Hens • Finals schedule to be published January 21 • Herman - Eggenhofer engagement • Shelly - Frank engagementhttps://digitalcommons.ursinus.edu/weekly/1419/thumbnail.jp

Radius constraints from high-speed photometry of 20 low-mass white dwarf binaries

We carry out high-speed photometry on 20 of the shortest-period, detached white dwarf binaries known and discover systems with eclipses, ellipsoidal variations (due to tidal deformations of the visible white dwarf), and Doppler beaming. All of the binaries contain low-mass white dwarfs with orbital periods less than 4 hr. Our observations identify the first eight tidally distorted white dwarfs, four of which are reported for the first time here, which we use to put empirical constraints on the mass-radius relationship for extremely low-mass (<0.30 Msun) white dwarfs. We also detect Doppler beaming in several of these binaries, which confirms the high-amplitude radial-velocity variability. All of these systems are strong sources of gravitational radiation, and long-term monitoring of those that display ellipsoidal variations can be used to detect spin-up of the tidal bulge due to orbital decay.Comment: 14 pages, 5 figures, accepted for publication in The Astrophysical Journa

Non-chemically amplified resists for 193-nm immersion lithography: Influence of absorbance on performance

The feasibility of three polymer systems for use as non chemically amplified resists for 193 nm lithography are discussed. The three systems are polycarbonates, polyphthalaldehydes and polysulfones. In general it was found that increased absorbance resulted in higher sensitivity to 193 nm light. However, the exception to this was the polycarbonates, which were found to undergo crosslinking due to an alkene group present in the polymer backbone. Although polyphthalaldehydes were very sensitive, their absorbance values were too high to be useful in a commercial environment. Absorbing polysulfones were found to be sensitive to 193 nm light and initial patterning results have been presented

The Ursinus Weekly, February 25, 1957

SGAs to sponsor forum on governments on Monday, Mar. 4 • Freshman women receive colors at program, Thurs. • Seniors to give original musical comedy, April 5, 6 • Lisle field representative to visit Ursinus tomorrow • Scholarship fund set up at U.C. by railroad company • Delta Pi man returns • Weekly to conduct vote on Wed. for best-dressed girl • UC Debating Club meets Lehigh and Rutgers of N.J. • Four charities to be supported in Campus Chest drive, March 4 to 15 • Sonnie Smith, Marge Struth voted May Queen, manager • Men\u27s government meets at advisor\u27s home • Curtain Club to present Valiant • WAA, Varsity Club hold annual dance, Friday • Curtain Club group plays for April announced • Future activities planned by U.C. Canterbury Club • Curtain Club announces name of Spring play • No classes Good Friday • Editorial: Memoranda for March 4 • Cynic • Report on the Perkiomen • Star-reaching • Who is the best-dressed woman at Ursinus? • Bears lose to Del., Rutgers; Meet division champs Wed. • U.C. to send Padula, Prutzman and Knauf to championships at G\u27burg • Prutzman stays undefeated as matmen topple cadets • Mermaids sink to Swarthmore, Wed. • Belles top G-burg; Drop first loss to Beaverhttps://digitalcommons.ursinus.edu/weekly/1422/thumbnail.jp

Two New Tidally Distorted White Dwarfs

We identify two new tidally distorted white dwarfs (WDs), SDSS J174140.49+652638.7 and J211921.96-001825.8 (hereafter J1741 and J2119). Both stars are extremely low mass (ELM, < 0.2 Msun) WDs in short-period, detached binary systems. High-speed photometric observations obtained at the McDonald Observatory reveal ellipsoidal variations and Doppler beaming in both systems; J1741, with a minimum companion mass of 1.1 Msun, has one of the strongest Doppler beaming signals ever observed in a binary system (0.59 \pm 0.06% amplitude). We use the observed ellipsoidal variations to constrain the radius of each WD. For J1741, the star's radius must exceed 0.074 Rsun. For J2119, the radius exceeds 0.10 Rsun. These indirect radius measurements are comparable to the radius measurements for the bloated WD companions to A-stars found by the Kepler spacecraft, and they constitute some of the largest radii inferred for any WD. Surprisingly, J1741 also appears to show a 0.23 \pm 0.06% reflection effect, and we discuss possible sources for this excess heating. Both J1741 and J2119 are strong gravitational wave sources, and the time-of-minimum of the ellipsoidal variations can be used to detect the orbital period decay. This may be possible on a timescale of a decade or less.Comment: 6 pages, 4 figures, accepted for publication in the Astrophysical Journa

Maxim

Quarterly newsletter of the North Harris Montgomery Community College District discussing news, events, and related topics to inform the community-at-large about the programs, services, and updates for the district