9,281 research outputs found
A VLBA Search for a Stimulated Recombination Line from the Accretion Region in NGC1275
The radio source 3C84, in NGC1275, has a two sided structure on parsec
scales. The northern feature, presumed to be associated with a jet moving away
from the Earth, shows strong evidence for free-free absorption. The ionized gas
responsible for that absorption would be a source of detectable stimulated
recombination line emission for a wide range of physical conditions. The VLBA
has been used to search for the H65 hydrogen recombination line. The
line is only expected to be seen against the northern feature which contains a
small fraction of the total radio flux density. This spatial discrimination
significantly aids the search for a weak line. No line was seen, with upper
limits of roughly 15% of the continuum over a velocity range of 1486 km/s with
resolutions up to 6.6 km/s. In the absence of a strong radiation field, this
would imply that the free-free absorbing gas has a wide velocity width, is
moving rapidly relative to the systemic velocity, or is concentrated in a thin,
high density structure. All of these possibilities are reasonably likely close
to an AGN. However, in the intense radiation environment of the AGN, even
considering only the radiation we actually observe passing through the
free-free absorbing gas, the non-detection is probably assured by a combination
of saturation and radiation damping.Comment: 14 pages with 4 postscript figures. Accepted for publication in the
April 2003 Astronomical Journa
Helium line detections from ELDWIM at 1.4 GHz
Helium line observations towards 11 Galactic positions using Westerbork
Synthesis Radio Telescope(WSRT) have been reported. These observations were
made towards nearby positions where already hydrogen lines were detected at
sufficiently high intensity(50mK) at 1.4 GHz. This approach gave a fair
chance for the detection of helium line as well, keeping in mind the relative
abundance(10%) of helium with respect to hydrogen. Care was also taken to avoid
the presence of HII regions along the line of sight so that the line emission
originates from the extended diffuse low density ionized component, ELDWIM of
the Galaxy. The observations have resulted in the detection of helium line
towards 5 positions out of 11 with signal to noise ratio(snr) 4. An
attempt has been made to associate detection/non-detection of helium line to
the presence of surrounding HII regions. A weighting scheme that accounts for
nearby( 500pc) HII regions, their distances and other factors produces
favourable results. It is seen from this weighting scheme that a higher weight
favours the detection of helium line while lower weight is associated with
non-detection. The idea is to correlate ionization of ELDWIM with the
surrounding HII regions.Comment: 15 pages, 6 figures, 3 tables, Published with minor changes in The
Astronomical Journa
Concluding remarks : entrepreneurship in low and moderate income communities
Community development
Who is the L3C Entrepreneur? The pioneers of social enterprise's revolutionary new suffix
This paper is not a scientifically valid survey of L3Cs. It is based on qualitative, anecdotal research only. It is not a quantitative analysis and should not substitute for such data. This paper is also not a technical paper or persuasive paper advocating for the L3C. Several individuals who have been entrenched in this movement for many years have articulated the technical merits and flaws very clearly. (For suggestions on detailed legal and technical analysis of the L3C, see Appendix B.) This paper also focuses mostly on L3C entrepreneurs, not its detractors. While several flaws, challenges, issues and concerns over the L3C are raised in this paper, we did not speak to those who have spoken out against the L3C
Who is the L3C Entrepreneur? Come along and experience the next chapter
Originally published in May 2010, we've spent the last 6 months speaking with social entrepreneurs launching new L3Cs, those who've been in the trenches for a while now and amazing thought leaders to provide you with an up-to-date, insider's look into all things L3C
Development of an interface for an ultrareliable fault-tolerant control system and an electronic servo-control unit
The NASA Ames Research Center sponsors a research program for the investigation of Intelligent Flight Control Actuation systems. The use of artificial intelligence techniques in conjunction with algorithmic techniques for autonomous, decentralized fault management of flight-control actuation systems is explored under this program. The design, development, and operation of the interface for laboratory investigation of this program is documented. The interface, architecturally based on the Intel 8751 microcontroller, is an interrupt-driven system designed to receive a digital message from an ultrareliable fault-tolerant control system (UFTCS). The interface links the UFTCS to an electronic servo-control unit, which controls a set of hydraulic actuators. It was necessary to build a UFTCS emulator (also based on the Intel 8751) to provide signal sources for testing the equipment
Improving medication practices for persons with intellectual and developmental disability: Educating direct support staff using simulation, debriefing, and reflection
Direct support professionals (DSP) are increasingly active in medication administration for people with intellectual and developmental disabilities (IDD), thus supplementing nursing and family caretakers. Providing workplace training of DSPs is often the duty of nursing personnel. This article presents empirical data and design suggestions for including simulations, debriefing, and written reflective practice during in-service training for DSPs in order to improve DSPs’ skills and confidence related to medication administration. Quantitative study results demonstrate that DSPs acknowledge that their skill-level and confidence rose significantly after hands-on simulations. The skill- level effect was statistically significant for general medication management -4.5 (p <0.001) and gastrointestinal medication management -4.4 (p < 0.001). Qualitative findings show a deep desire by DSPs to not just be “pill poppers” but to understand the medical processes, causalities, and consequences of their medication administration. On the basis of our results, the authors make recommendations regarding how to combine DSP workplace simulations and debriefing with written reflective practice in DSP continuing education
Advancing Faculty DiversityThrough Self-Directed Mentoring
Mentoring is widely acknowledged to be important in career success, yet may be lacking for female and minority law professors, contributing to disparities in retention and promotion of diverse faculty. This Article presents the results of a unique diversity mentoring program conducted at one law school. Mentoring is often thought of as something directed by the mentor on behalf of the protégé. Our framework inverts that model, empowering diverse faculty members to proactively cultivate their own networks of research mentors. The studied intervention consisted of modest programming on mentorship, along with supplemental travel funds to focus specifically on travel for the purpose of cultivating mentors beyond one’s own institution. Participants were responsible for setting their own mentorship goals, approaching mentors and arranging meetings, and reporting annually on their activities and progress. Both quantitative and qualitative evidence demonstrate that the program has been effective along its measurable goals in its first year. Participants report growing their networks of mentors, receiving significant advice on research and the tenure process, and being sponsored for new opportunities. The authors conclude that this type of mentoring initiative, if more broadly applied, could have a significant impact on reducing disparities in retention and promotion in the legal academy. To facilitate such replication, the Article describes both the process of designing the program and the actual operation of the program as carried out at one school. In sum, the Article offers a concrete starting point for discussions at any law school interested in advancing faculty diversity through improved mentoring
The First Amendment, Social Media, and the Public Schools: Emergent Themes and Unanswered Questions
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