Radial Velocities of Six OB Stars

We present new results from a radial velocity study of six bright OB stars with little or no prior measurements. One of these, HD 45314, may be a long-period binary, but the velocity variations of this Be star may be related to changes in its circumstellar disk. Significant velocity variations were also found for HD 60848 (possibly related to nonradial pulsations) and HD 61827 (related to wind variations). The other three targets, HD 46150, HD 54879, and HD 206183, are constant velocity objects, but we note that HD 54879 has H$\alpha$ emission that may originate from a binary companion. We illustrate the average red spectrum of each target.Comment: Accepted for publication in PASP July 2007 issu

The Long Period, Massive Binaries HD 37366 and HD 54662: Potential Targets for Long Baseline Optical Interferometry

We present the results from an optical spectroscopic analysis of the massive stars HD 37366 and HD 54662. We find that HD 37366 is a double-lined spectroscopic binary with a period of 31.8187 +/- 0.0004 days, and HD 54662 is also a double lined binary with a much longer period of 557.8 +/- 0.3 days. The primary of HD 37366 is classified as O9.5 V, and it contributes approximately two-thirds of the optical flux. The less luminous secondary is a broad-lined, early B-type main-sequence star. Tomographic reconstruction of the individual spectra of HD 37366 reveals absorption lines present in each component, enabling us to constrain the nature of the secondary and physical characteristics of both stars. Tomographic reconstruction was not possible for HD 54662; however, we do present mean spectra from our observations that show that the secondary component is approximately half as bright as the primary. The observed spectral energy distributions (SEDs) were fit with model SEDs and galactic reddening curves to determine the angular sizes of the stars. By assuming radii appropriate for their classifications, we determine distance ranges of 1.4 - 1.9 and 1.2 - 1.5 kpc for HD 37366 and HD 54662, respectively.Comment: 27 pages, 8 figures, Accepted for publication in Ap

Optically Thick Radio Cores of Narrow-Waist Bipolar Nebulae

We report our search for optically thick radio cores in sixteen narrow-waist bipolar nebulae. Optically thick cores are a characteristic signature of collimated ionized winds. Eleven northern nebulae were observed with the Very Large Array (VLA) at 1.3 cm and 0.7 cm, and five southern nebulae were observed with the Australia Telescope Compact Array (ATCA) at 6 cm and 3.6 cm. Two northern objects, 19W32 and M 1-91, and three southern objects, He 2-25, He 2-84 and Mz 3, were found to exhibit a compact radio core with a rising spectrum consistent with an ionized jet. Such jets have been seen in M 2-9 and may be responsible for shaping bipolar structure in planetary nebulae.Comment: 29 pages, accepted for publication in Ap

Catalog of Galactic Beta Cephei Stars

We present an extensive and up-to-date catalog of Galactic Beta Cephei stars. This catalog is intended to give a comprehensive overview of observational characteristics of all known Beta Cephei stars. 93 stars could be confirmed to be Beta Cephei stars. For some stars we re-analyzed published data or conducted our own analyses. 61 stars were rejected from the final Beta Cephei list, and 77 stars are suspected to be Beta Cephei stars. A list of critically selected pulsation frequencies for confirmed Beta Cephei stars is also presented. We analyze the Beta Cephei stars as a group, such as the distributions of their spectral types, projected rotational velocities, radial velocities, pulsation periods, and Galactic coordinates. We confirm that the majority of these stars are multiperiodic pulsators. We show that, besides two exceptions, the Beta Cephei stars with high pulsation amplitudes are slow rotators. We construct a theoretical HR diagram that suggests that almost all 93 Beta Cephei stars are MS objects. We discuss the observational boundaries of Beta Cephei pulsation and their physical parameters. We corroborate that the excited pulsation modes are near to the radial fundamental mode in frequency and we show that the mass distribution of the stars peaks at 12 solar masses. We point out that the theoretical instability strip of the Beta Cephei stars is filled neither at the cool nor at the hot end and attempt to explain this observation

Extrinsic Magnetotransport Phenomena in Ferromagnetic Oxides

This review is focused on extrinsic magnetotransport effects in ferromagnetic oxides. It consists of two parts; the second part is devoted to an overview of experimental data and theoretical models for extrinsic magnetotransport phenomena. Here a critical discussion of domain-wall scattering is given. Results on surfacial and interfacial magnetism in oxides are presented. Spin-polarized tunnelling in ferromagnetic junctions is reviewed and grain-boundary magnetoresistance is interpreted within a model of spin-polarized tunnelling through natural oxide barriers. The situation in ferromagnetic oxides is compared with data and models for conventional ferromagnets. The first part of the review summarizes basic material properties, especially data on the spin-polarization and evidence for half-metallicity. Furthermore, intrinsic conduction mechanisms are discussed. An outlook on the further development of oxide spin-electronics concludes this review.Comment: 133 pages, 47 figures, submitted to Rep. Prog. Phy

all - simply - immediately: service in medical libraries: Annual Meeting 2010 of "Arbeitsgemeinschaft für Medizinisches Bibliothekswesen" (AGMB e.V.) 27th to 29th September in Mainz

The annual meeting 2010 of "Arbeitsgemeinschaft für Medizinisches Bibliothekswesen" (AGMB e.V.) took place 27th-29th September at Mainz university.During the main event for Advanced training of medical librarianship in Germany, Austria and Switzerland the following topics were presented and discussed: Increasing digitalization of scientific communication and the consequences, innovative services in hybrid libraries (virtual textbook collections and E-Books On-Demand), education (Master degree programm "Informations- und Wissensmanagement" in Hannover), concept and building of the medical library at Düsseldorf university (O.A.S.E.), quality management according to ISO 9001, subito (new services based on § 5 2a+b UrhG), future of the programm "Nationallizenzen" and "Allianz-Initiative der deutschen Wissenschaftsorganisationen", information l itera cy (particularly blended-learning), public relation and new strategies for communication and services, future concepts for medical libraries, library services in a UK research institute, reference management, Web 2.0 and other emerging technologies, BibNet.org, Cochrane library, MedPilot, PubMed.All relevant publishers and providers for medical libraries presented new products and services in an accompanying exhibition.Vom 27.-29.9.2010 fand an der Universität Mainz die Jahrestagung der Arbeitsgemeinschaft für Medizinisches Bibliothekswesen (AGMB e.V.) statt.Auf der zentralen Fortbildungsveranstaltung für das medizinische Bibliothekswesen in Deutschland, Österreich und der Schweiz konnten sich die Teilnehmer unter anderem über folgende Themen informieren: Zunehmende Digitalisierung der wissenschaftlichen Kommunikation und deren Auswirkungen, innovative Services in Hybridbibliotheken (Virtuelle Lehrbuchsammlung und E-Books On-Demand), Ausbildung (Weiterbildungs-Masterstudiengang Informations- und Wissensmanagement in Hannover), Neubau der Fachbibliothek Medizin O.A.S.E. an der Universität Düsseldorf, Qualitätsmanagement nach ISO 9001, subito (neue Dienste auf der Basis von § 52a+b UrhG), Zukunft der Nationallizenzen und Allianz-Initiative der deutschen Wissenschaftsorganisationen, Informationskompetenz am Beispiel von Blended-Learning, Public Relation sowie neue Kommunikations- und Servicestrategien, Zukunftskonzepte für Medizinbibliotheken, Dienstleistungen der Bibliothek an einem Forschungsinstitut in Großbritannien, Literaturverwaltung, Web 2.0 und andere Emerging Technologies, BibNet.org, Cochrane Library, MedPilot, PubMed.In einer begleitenden Firmenausstellung präsentierten alle für medizinische Bibliotheken wichtigen Verlage und Dienstleister neue Produkte und Services

MAGNETIC AND TRANSPORT PROPERTIES OF a-UxGd1-x FILMS

a - UxGd1-x films show Arrott plots and AC susceptibility characteristic of random-exchange dominated systems. Both the resistivity and the magnetoresistance show the possible coexistence of magnetic scattering and weak-localization effects below a temperature T1. The anisotropic magnetoresistance is zero as expected for a Gd containing system (S-state)