Use of optical fibers in spectrophotometry

The use of single or small numbers of fiber optic fibers in astronomical spectroscopy with the goal of greater spectrophotometric and radial velocity accuracy is discussed. The properties of multimode step index fibers which are most important for this application are outlined, as are laboratory tests of currently available fibers

ROSAT x ray survey observations of active chromospheric binary systems and other selected sources

The connection between processes that produce optical chromospheric activity indicators and those that produce x-rays in RS CVn binary systems by taking advantage of the ROSAT All-Sky Survey (RASS) results and our unique ground-based data set was investigated. In RS CVn systems, excess emission in the Ca 2 resonance (K & H) and infrared triplet (IRT) lines and in the Balmer lines of hydrogen is generally cited as evidence for chromospheric activity, which is usually modeled as scaled up solar-type activity. X-ray emission in RS CVn systems is believed to arise from coronal loop structures. Results from spectra data obtained from RASS observations are discussed and presented

Li I enhancement during a long-duration stellar flare

We report the possible detection of a Li I 6708 AA line enhancement during an unusual long-duration optical flare in the recently discovered, X-ray/EUV selected, chromospherically active binary 2RE J0743+224. The Li I equivalent width (EW) variations follow the temporal evolution of the flare and large changes are observed in the intensity of the line. The maximum Li I enhancement occurs just after the maximum chromospheric emission observed in the flare. A significant increase of the 6Li/7Li isotopic ratio is also detected. No significant simultaneous variations are detected in other photospheric lines. Neither line blends nor starspots seem to be the primary cause of the observed Li I line variation. From all this we suggest that this Li I enhancement is produced by spallation reactions during the flare.Comment: Latex file with 5 pages, 2 figures tar'ed gzip'ed. Full postscript (text and figures) available at http://www.ucm.es/OTROS/Astrof/pub_dmg.html To be published in A&A, Lette

An Analysis of Cooperating Teacher Feedback: A Qualitative Inquiry

Cooperating teachers are a key component to the success of student teaching internships, serving an integral part in “raising” a teacher. To effectively facilitate the student teaching internship, teacher preparation programs must identify cooperating teachers who align philosophically with the pedagogical training delivered by university programs (Korthagen & Kessels, 1999; Tom, 1997), specifically, cooperating teachers who can reinforce the theoretical framework underpinning the professional coursework pre-service teachers experience in university teacher preparation programs. This qualitative study sought to better understand the feedback provided to future school-based agricultural education (SBAE) teachers during their student teaching experience. Through initial and secondary coding, the research team identified themes among the feedback provided to student teachers by their cooperating teachers. The study revealed cooperating teacher feedback reflects the pedagogical training provided via the teacher preparation program, specifically, around effective teaching behaviors. Understanding the cooperating teacher feedback provides insight for teacher preparation programs

On single-amplifier immittance inverters and their use in active filter design

Imperial Users onl

Nucleon Vector Strangeness Form Factors: Multi-pion Continuum and the OZI Rule

We estimate the 3 \pi continuum contribution to the nucleon strange quark vector current form factors, including the effect of a 3 \pi \rho \pi resonance. We find the magnitude of this OZI-violating contribution to be comparable to that of typical OZI-allowed contributions. We also study the isoscalar electromagnetic form factors, and find that the presence of a \rho \pi resonance in the multi-pion continuum may generate an appreciable contribution.Comment: 18 pages, LaTex, 4 PS figures, uses epsf.sty, rotate.sty, revised to include 3\pi -> \omega resonance and e^+ e^- dat

The Paternalistic Relationship: Authenticity and credibility as a source of healthy relationships

This article explores the how the Paternalistic Leadership model can be viewed as part of a relationship-based paradigm of leadership, and can incorporate concepts such as credibility and authenticity. The review highlights the need to understand paternalistic leadership as an approach to establishing productive relationships within a cultural context, with implications for researchers and practitioners in both collectivist and individualistic cultures