16,691 research outputs found
Social Policy Resources for Social Work: Grey Literature and the Internet
Accreditation standards for professional schools offering social work degrees mandate curriculum content that provides students with skills to analyze, formulate, and influence social policies. An important source of analytical thinking about social policy is the “grey” literature issued by public policy organizations, think tanks, university-based research institutions, professional organizations, etc., that is increasingly available via the Internet. This research surveys library social work subject pages for content and links related to the social policy grey literature. A coding scheme was developed that counted the number of paths to relevant grey literature from the libraries’ subject guides. The results of the study suggest that there is a great deal of variance across institutions in how much help they provide users. Libraries must do a better job guiding users to the policy organizations that produce reports, briefs, newsletters, etc., that are important to social policy problem solving and implementation
Run-in with chemical additive protects gear surface
Run-in treatment provides a protective coating on turbopump gear surfaces so that they are capable of operation under marginal conditions in mineral oil and diester lubricants. This treatment protects highly loaded gears during relatively short-term operation
Laboratory oscillator strengths of Sc I in the near-infrared region for astrophysical applications
Context. Atomic data is crucial for astrophysical investigations. To
understand the formation and evolution of stars, we need to analyse their
observed spectra. Analysing a spectrum of a star requires information about the
properties of atomic lines, such as wavelengths and oscillator strengths.
However, atomic data of some elements are scarce, particularly in the infrared
region, and this paper is part of an effort to improve the situation on near-IR
atomic data. Aims. This paper investigates the spectrum of neutral scandium, Sc
i, from laboratory measurements and improves the atomic data of Sc i lines in
the infrared region covering lines in R, I, J, and K bands. Especially, we
focus on measuring oscillator strengths for Sc i lines connecting the levels
with 4p and 4s configurations. Methods. We combined experimental branching
fractions with radiative lifetimes from the literature to derive oscillator
strengths (f - values). Intensity-calibrated spectra with high spectral
resolution were recorded with Fourier transform spectrometer from a hollow
cathode discharge lamp. The spectra were used to derive accurate oscillator
strengths and wavelengths for Sc i lines, with emphasis on the infrared region.
Results. This project provides the first set of experimental Sc i lines in the
near-infrared region for accurate spectral analysis of astronomical objects. We
derived 63 log(g f ) values for the lines between 5300{\AA} and 24300{\AA}. The
uncertainties in the f -values vary from 5% to 20%. The small uncertainties in
our values allow for an increased accuracy in astrophysical abundance
determinations.Comment: Accepted on 25 August 2015 by A&
Microscale application of column theory for high resolution force and displacement sensing
We present the design, fabrication and experimental validation of a novel
device that exploits the amplification of displacement and attenuation of
structural stiffness in the post-buckling deformation of slender columns to
obtain pico-Newton force and nanometer displacement resolution even under an
optical microscope. The extremely small size, purely mechanical sensing scheme
and vacuum compatibility of the instrument makes it compatible with existing
visualization tools of nanotechnology. The instrument has a wide variety of
potential applications ranging from electro-mechanical characterization of one
dimensional solids to single biological cells
A total life prediction model for stress concentration sites
Fatigue crack growth tests were performed on center crack panels and radial crack hole samples. The data were reduced and correlated with the elastic parameter K taking into account finite width and corner crack corrections. The anomalous behavior normally associated with short cracks was not observed. Total life estimates for notches were made by coupling an initiation life estimate with a propagation life estimate
Wind tunnel tests of Space Shuttle external tank insulation material in the aerothermal tunnel at elevated (1440 deg F) total temperatures
Tests of the space shuttle external tank foam insulation were conducted in the von Karman Gas Dynamics Facility Tunnel C. For these tests, Tunnel C was run at Mach 4 with a total temperature of 1440 F and a total pressure which varied from 30-100 psia. Cold wall heating rates were changed by varying the test article support wedge angle and by adding and removing a shock generator or a cylindrical protuberance. Selected results are presented to illustrate the test techniques and typical data obtained
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