Phenolic cutter for machining foam insulation

Pre-pregged fiber glass is an efficient abrasive for machining polystyrene and polyurethane foams. It bonds easily to any cutter base made of aluminum, steel, or phenolic, is inexpensive, and is readily available

The Infrared Massive Stellar Content of M83

We present an analysis of archival Spitzer images and new ground-based and Hubble Space Telescope (HST) near-infrared (IR) and optical images of the field of M83 with the goal of identifying rare, dusty, evolved massive stars. We present point source catalogs consisting of 3778 objects from $Spitzer$ Infrared Array Camera (IRAC) Band 1 (3.6 $\mu$m) and Band 2 (4.5 $\mu$m), and 975 objects identified in Magellan 6.5m FourStar near-IR $J$ and $K_{\rm s}$ images. A combined catalog of coordinate matched near- and mid-IR point sources yields 221 objects in the field of M83. Using this photometry we identify 185 massive evolved stellar candidates based on their location in color-magnitude and color-color diagrams. We estimate the background contamination to our stellar candidate lists and further classify candidates based on their appearance in $HST$ Wide Field Camera 3 (WFC3) observations of M83. We find 49 strong candidates for massive stars which are very promising objects for spectroscopic follow-up. Based on their location in a $B-V$ versus $V-I$ diagram, we expect at least 24, or roughly 50%, to be confirmed as red supergiants.Comment: 32 pages, 23 figures, accepted for publication in A&

3-quasi-Sasakian manifolds

In the present paper we carry on a systematic study of 3-quasi-Sasakian manifolds. In particular we prove that the three Reeb vector fields generate an involutive distribution determining a canonical totally geodesic and Riemannian foliation. Locally, the leaves of this foliation turn out to be Lie groups: either the orthogonal group or an abelian one. We show that 3-quasi-Sasakian manifolds have a well-defined rank, obtaining a rank-based classification. Furthermore, we prove a splitting theorem for these manifolds assuming the integrability of one of the almost product structures. Finally, we show that the vertical distribution is a minimum of the corrected energy.Comment: 17 pages, minor modifications, references update

Praziquantel coverage in schools and communities targeted for the elimination of urogenital schistosomiasis in Zanzibar: a cross-sectional survey

© 2015 Knopp et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. The attached file is the published version of the article

On certain surfaces in the Euclidean space E3{\mathbb{E}}^3

In the present paper we classify all surfaces in \E^3 with a canonical principal direction. Examples of these type of surfaces are constructed. We prove that the only minimal surface with a canonical principal direction in the Euclidean space ${\mathbb{E}}^3$ is the catenoid.Comment: 13 Latex page

Role of branched-chain fatty acids in pH stress tolerance in Listeria monocytogenes

In alkaline conditions, Listeria monocytogenes cells develop higher proportions of branched-chain fatty acids (FAs), including more anteiso forms. In acid conditions, the opposite occurs. Reduced growth of pH-sensitive mutants at adverse pH (5.0/9.0) was alleviated by the addition of 2-methylbutyrate (an anteiso-FA precursor), suggesting that anteiso-FAs are important in adaptation to adverse pH. The balance between anteiso- and iso-FAs may be more important than changes in the amounts and/or degrees of saturation of FAs in pH adaptation

The Deuterium Abundance at z=0.701 towards QSO 1718+4807

We present constraints on the deuterium to hydrogen ratio (D/H) in the metal-poor gas cloud at redshift $z=0.701$ towards QSO 1718+4807. We use new Keck spectra in addition to Hubble Space Telescope (HST) and International Ultraviolet Explorer (IUE) spectra. We use an improved redshift and a lower \HI column density to model the absorption. The HST spectrum shows an asymmetric Lyman-$\alpha$ (\lya) feature which is produced by either \HI at a second velocity, or a high abundance of D. Three models with a single simple H+D component give $8 \times 10^{-5} < D/H < 57 \times 10^{-5}$ (95%), a much larger range than reported by Webb et al (1997a,b). A more sophisticated velocity distribution, or a second component is necessary for lower D/H. With two components, which could be a part of one absorbing structure, or separate clouds in a galaxy halo, we find $D/H < 50 \times 10^{-5}$. We do not know if this second component is present, but it is reasonable because 40 -- 100% of absorption systems with similar redshifts and \HI column densities have more than one component.Comment: 13 pages, 4 figures, to appear in the Astronomical Journal (Jan 1999

Wind tunnel testing of a novel wingsuit design

A wingsuit is a special suit that is worn to allow the user to fly after jumping off of a high cliff. The wingsuit creates an airfoil shape by adding wings of material between the arms and the sides as well as a tail consisting of material between the legs. The wingsuit allows for the creation of lift and thus human flying. A new and novel wingsuit design is proposed based on the design of a delta wing aircraft. This new wingsuit has material leading from the side of the head and connecting to the top of the arms, extending the area of the forward wing. Using a mannequin in a wind tunnel, the aerodynamic performance of the new wingsuit will be measured and compared to that of the current wingsuit design. The results show that the redesigned wingsuit had a lower lift-to-drag ratio in most testing scenarios. The decrease in lift-to-drag ratio was due to the combination of an increased lift and a higher increased drag