3,341 research outputs found
A Roadmap for Integrating Human Rights Into the World Bank Group
Offers a framework for linking effective international development and poverty reduction with human rights, including empowering communities to use the World Bank Group's grievance mechanisms. Outlines accomplishments, shortfalls, and recommendations
Free-Flight Tests of Fifth-Stage Scout Entry Vehicle at Mach Numbers of 5 and 17
Measurements have been made in air at two Mach numbers of the static stability, normal force, and drag of a version of the fifth-stage Scout entry vehicle. The most significant result was that the design center of gravity led to a condition of static instability at small angles of attack at Mach number 17. At this Mach number, the static stability was a highly nonlinear function of the angle of attack. A useful method for analyzing free-flight data having this nonlinear behavior is included in this report. Comparisons were made between the measured aerodynamic coefficients and those estimated by Newtonian impact theory and by a method developed by Seiff and Whiting. The latter method gave good estimates of the normal-force-curve slope at both Mach numbers and of the moment-curve slope at the lower Mach number. It resulted in an overestimation of the static stability at Mach number 17, although it gave results decidedly closer to the experimental value than did Newtonian impact theory
Changing Farm Structure and the Distribution of Farm Payments and Federal Crop Insurance
The distribution of commodity-related payments and Federal crop insurance indemnities to U.S. farmers has shifted to larger farms as more and more U.S. agricultural production is done on those farms. Since the operators of larger farms tend to have higher household incomes than other farm operators, commodity-related program payments and Federal crop insurance indemnities also have shifted to higher income households. By 2009, half of commodity-related program payments went to farms operated by households earning over 209,000 and 10 percent went to farms operated by households with incomes of at least 12.3 billion in 2009. Total Federal crop insurance indemnity payments were $5.2 billion in 2009.farm program payments, Federal crop insurance, Agricultural Resource Management Survey, structural change, income caps, payment limits., Agricultural and Food Policy, Agricultural Finance, Industrial Organization, Public Economics,
The performance of arm locking in LISA
For the laser interferometer space antenna (LISA) to reach it's design
sensitivity, the coupling of the free running laser frequency noise to the
signal readout must be reduced by more than 14 orders of magnitude. One
technique employed to reduce the laser frequency noise will be arm locking,
where the laser frequency is locked to the LISA arm length. This paper details
an implementation of arm locking, studies orbital effects, the impact of errors
in the Doppler knowledge, and noise limits. The noise performance of arm
locking is calculated with the inclusion of the dominant expected noise
sources: ultra stable oscillator (clock) noise, spacecraft motion, and shot
noise. Studying these issues reveals that although dual arm locking [A. Sutton
& D. A Shaddock, Phys. Rev. D 78, 082001 (2008).] has advantages over single
(or common) arm locking in terms of allowing high gain, it has disadvantages in
both laser frequency pulling and noise performance. We address this by
proposing a hybrid sensor, retaining the benefits of common and dual arm
locking sensors. We present a detailed design of an arm locking controller and
perform an analysis of the expected performance when used with and without
laser pre-stabilization. We observe that the sensor phase changes beneficially
near unity-gain frequencies of the arm-locking controller, allowing a factor of
10 more gain than previously believed, without degrading stability. We show
that the LISA frequency noise goal can be realized with arm locking and
Time-Delay Interferometry only, without any form of pre-stabilization.Comment: 28 pages, 36 figure
Cascaded half-harmonic generation of femtosecond frequency combs in mid-IR
For the growing demand of frequency combs in mid-infrared (mid-IR), known as
the "molecular fingerprint" region of the spectrum [1], down conversion of
near-IR frequency combs through half- harmonic generation offers numerous
benefits including high conversion efficiency and intrinsic phase and frequency
locking to the near-IR pump [2]. Hence cascaded half-harmonic generation
promises a simple path towards extending the wavelength coverage of stable
frequency combs. Here, we report a two-octave down-conversion of a frequency
comb around 1 {\mu}m through cascaded half-harmonic generation with ~64%
efficiency in the first stage, and ~18% in the second stage. We obtain
broadband intrinsically-frequency-locked frequency combs with ~50-fs pulses at
~2 {\mu}m and ~110-fs pulses at ~4 {\mu}m. These results indicate the
effectiveness of half-harmonic generation as a universal tool for efficient
phase- and frequency-locked down-conversion, which can be beneficial for
numerous applications requiring long-wavelength coherent sources
Science through drama: a multiple case exploration of the characteristics of drama activities used in secondary science lessons
Over twenty years of research into the use of cross curricular drama in secondary Science has indicated that this medium enables learning of affective, cognitive and procedural knowledge. To date, academic research has tended to frame successful drama pedagogy as resulting from a Drama-in-Education approach, incorporating extended role plays and simulations of social events. By contrast, research has rarely focused on the scope and context of drama which is devised and used by 'real people in real situations' (Cohen et al. 2000). Indications from non-academic literature and informal education practice suggest that there is a gap in our knowledge between research and classroom practise. This study focussed on teachers' own drama activities in five Science lessons taught across schools in Cambridge, Kent, and Hertfordshire. Their classes spanned the ages of 12-16 in the subjects of Chemistry, Biology, and Physics. This study explored the drama forms, teaching objectives, and characteristics by which drama was perceived to enable learning in Science. The findings revealed that drama activities were used to convey a variety of topics that have not yet been recorded in academic literature, and revealed a greater scope for the teaching abstract scientific concepts through mime and role play. These activities were perceived to develop students’ visualisation through a range of modalities, which included embodied sensation and anthropomorphic metaphors. Some features reflected the development of Thought Experiment skills. A pedagogic model was produced based on different levels of interactive talk and multimodal communication
A pasture program for Tennessee
When it is considered that out of 19,085,837 acres of land in farms in Tennessee, 5,643,998 acres are in pasture, one readily sees the importance of pasture in the State. Of the total acreage in farm land, 15 per cent is in plowable pasture.
The farmers of Tennessee have long used their pasture land as a source of free feed. The necessity for replacing the fertility removed by grazing animals has not been considered. Very little attention has been given to reseeding pastures which are running out. Livestock have been allowed to graze at will, often times, completely denuding the landscape. Weeds and other undesirable plants have been allowed to come into pastures, in many cases completely taking them, without any attempt to control their advances.
After considering the importance of pastures in Tennessee, and the pasture management practices the farmers are following, one readily comes to the conclusion that there is a great need for pasture improvement in the State. It is with this thought in mind that this paper has been written. An attempt has been made to set up a sound pasture program for the State, based upon proven, sound, scientific principles
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