Superconductivity of lanthanum revisited: enhanced critical temperature in the clean limit

The thickness dependence of the superconducting energy gap $\Delta_{\rm{La}}$ of double hexagonally close packed (dhcp) lanthanum islands grown on W(110) is studied by scanning tunneling spectroscopy, from the bulk to the thin film limit. Superconductivity is suppressed by the boundary conditions for the superconducting wavefunction at the surface and W/La interface, leading to a linear decrease of the critical temperature $T_c$ as a function of the inverse film thickness. For thick, bulk-like films, $\Delta_{\rm{La}}$ and $T_c$ are 40% larger as compared to literature values of dhcp La measured by other techniques. This finding is reconciled by examining the effects of surface contamination as probed by modifications of the surface state, suggesting that the large $T_c$ originates in the superior purity of the samples investigated here.Comment: 14 pages, 7 figure

Spectra of Maser Radiation from a Turbulent, Circumnuclear Accretion Disk. III. Circular polarization

Calculations are performed for the circular polarization of maser radiation from a turbulent, Keplerian disk that is intended to represent the sub-parsec disk at the nucleus of the galaxy NGC4258. The polarization in the calculations is a result of the Zeeman effect in the regime in which the Zeeman splitting is much less than the spectral linebreadth. Plausible configurations for turbulent magnetic and velocity fields in the disk are created by statistical methods. This turbulence, along with the Keplerian velocity gradients and the blending of the three hyperfine components to form the $6_{16} - 5_{23}$ masing transition of water, are key ingredients in determining the appearance of the polarized spectra that are calculated. These spectra are quite different from the polarized spectra that would be expected for a two-level transition where there is no hyperfine structure. The effect of the hyperfine structure on the polarization is most striking in the calculations for the maser emission that represents the central (or systemic) features of NGC4258. Information about magnetic fields is inferred from observations for polarized maser radiation and bears on the structure of accretion disks.Comment: Latex, uses aastex, eucal, to be published in the Astrophysical Journa

Information exchange and future plans of Slovenian cattle farmers under EU policies

After accession to EU, farmers in the new-member states have to adjust to the EU agricultural policies and market. In Slovenia an analysis is made of the farm development plans and information exchange under quota and CAP. Three research questions were addressed: what information is received and how; how does the farmer prefer to receive information and what kind; how to make decisions to react to the new EU policies concerning farm management and future plans. These questions were linked to the base variables, being the farm and farmers’ characteristics. As tool a questionnaire was distributed to dairy farmers. 1114 questionnaires, 22% of the distributed ones have been returned anonymously, implying that 11% of the dairy farmers’ population is part of the analysis. It appeared that the research sample of farmers used represents the more future oriented farmers. As main factors describing the farm and farmers’ characteristics were found farm size, age and number of other activities than dairy. Results show that nearly all farmers did receive information about some specific aspects of the quota system. Communication channels dealing with this administrative info and also with farm management advice are divers, but frequency of direct contact with advisors may be less than predicted. Results also indicate a very significant demand for info about strategic planning, farm management aspects and EU premium programs, especially about CAP general policies and milk premiums, and a considerable activity in farm planning. About 40% of farmers choose for keeping the farm business the same and 50% intend to develop the farm further.CAP, Slovenian cattle farmers, information, decisions, future plans, Community/Rural/Urban Development, Q18,

The library and undergraduate research in the liberal arts: Present contributions and future opportunities

This study sought to describe library value as seen through its various contributions to the mentored undergraduate research experiences of students in the arts, humanities, and social sciences at Hope College. Concurrently, it explored new opportunities for how librarians might become more directly connected with students involved in this hallmark of the academic program. Findings were intended to both highlight existing library contributions and initiate a well-informed movement toward aligning library priorities with the greater institutional academic mission

Show Me the Article!: Helping Students Understand the Library\u27s Role in Accessing Scholarly Information

A fundamental concept that students need to understand about performing research at the college/university level is that, contrary to what they may believe or have been accustomed to thinking, the entire sum of human knowledge is not openly accessible to anyone for free via the Internet. Often times, students need to see it to believe it –or, more importantly, grasp it–by experiencing first-hand how the library and free web intersect. We should not assume that the divide between what is available freely on the Internet and the content provided by, and only accessible via campus libraries is automatically or commonly understood by first year students. In fact, for many students there is likely no perceivable divide at all, but rather a blurred grey area of simply “online.

The Information Literacy Imperative in Higher Education

This article contends that information literacy should be considered a standard component in a 21st century liberal education. It explores the role of libraries and librarians within this context while contrasting the Google it mentality with deep researching and critical thinking about information and the information-seeking process, both in libraries and in the free online environment