6,160 research outputs found
Rationale and protocol for a systematic review and meta-analysis on reduced data gathering in people with delusions
Analysis of AVHRR, CZCS and historical in situ data off the Oregon Coast
The original scientific objectives of this grant were to: (1) characterize the seasonal cycles and interannual variability for phytoplankton concentrations and sea surface temperature (SST) in the California Current using satellite data; and (2) to explore the spatial and temporal relationship between these variables and surface wind forcing. An additional methodological objective was to develop statistical methods for forming mean fields, which minimize the effects of random data gaps and errors in the irregularly sampled CZCS (Coastal Zone Color Scanner) and AVHRR (Advanced Very High Resolution Radiometer) satellite data. A final task was to evaluate the level of uncertainty in the wind fields used for the statistical analysis. Funding in the first year included part of the cost of an image processing system to enable this and other projects to process and analyze satellite data. This report consists of summaries of the major projects carried out with all or partial support from this grant. The appendices include a list of papers and professional presentations supported by the grant, as well as reprints of the major papers and reports
Effect of boattail geometry on the acoustics of parallel baffles in ducts
Sound attenuation and total pressure drop of parallel duct baffles incorporating certain boattail geometries were measured in the NASA Ames Research Center 7- by 10-Foot Wind Tunnel. The baseline baffles were 1.56 m long and 20 cm thick, on 45-cm center-to-center spacings, and spanned the test section from floor to ceiling. Four different boattails were evaluated: a short, smooth (nonacoustic) boattail; a longer, smooth boattail; and two boattails with perforated surfaces and sound-absorbent filler. Acoustic measurements showed the acoustic boattails improved the sound attenuation of the baffles at approximately half the rate to be expected from constant-thickness sections of the same length; that is, 1.5 dB/n, where n is the ratio of acoustic treatment length to duct passage width between baffles. The aerodynamic total pressure loss was somewhat sensitive to tail geometry. Lengthening the tails to reduce the diffusion half-angle from 11 to 5 degrees reduced the total pressure loss approximately 9%. Perforating the boattails, which increased the surface roughness, did not have a large effect on the total pressure loss. Aerodynamic results are compared with a published empirical method for predicting baffle total pressure drop
Notes on Training of Captive Elephants
Benefits from training captive animals are significant to the safety of both animal and human. Training programs should address two fundamental considerations: 1) increased manageability for safety in maintenance and medical care, and 2) enhancement of psychological and physiological health and possibly to provide increased resistance to disease and environmental stress. Command vocabulary should be simple, minimized, and the performance repertoire maximized within appropriate limits. Trainer and animal relationship should be based upon mutual respect and an understanding of the constraints imposed within the captive environment
Characterization of 1.55-μm pulses from a self-seeded gain-switched Fabry-Pérot laser diode using frequency-resolved optical gating
The intensity and frequency chirp of picosecond pulses from a self-seeded gain-switched Fabry-Perot laser diode have been directly measured using the technique of frequency-resolved optical gating. Measurements over an output sidemode suppression ratio (SMSR) range of 15-35 dB show that higher SMSR's are associated with an increasingly linear frequency chirp across the output pulses. This complete pulse characterization allows the conditions for optimum pulse compression to be determined accurately, and indicates that transform-limited, pedestal free pulses can be obtained at an SMSR of 35 dB
Teachers’ collaborative dialogues in contexts of lesson study
esson Study is a model of teacher professional development that has seen a worldwide increase in popularity in recent years. Teachers collaboratively review their approaches through planning and reflecting on cycles of 'research lessons'. Dialogue therefore becomes a core mechanism in the development of their learning and practice. This chapter aims to provide an overview of the nature and potential of Lesson Study professional dialogues. It draws on data from one large-scale project with Mathematics teachers from primary and secondary schools in London. Through a qualitative analysis of case study examples, the chapter aims to demonstrate features of these dialogues that are productive in relation to subsequent practice development. Implications for teacher professional development are discussed
Depressed youth, suicidality and antidepressants
The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.Robert D Goldney, Peter R Mansfield, Melissa K Raven, Jon N Jureidini, Joseph M Rey, Michael J Dudley, Duncan Toplis
Characterization of nonlinear switching in a figure-of-eight fiber laser using frequency-resolved optical gating
The measurement technique of frequency-resolved optical gating is applied to determine the nonlinear switching characteristics of a passively modelocked figure-of-eight erbium-doped fiber laser. By completely characterizing the intensity and phase of the laser output pulses, the intracavity fields in the nonlinear amplifying loop mirror of the laser cavity are determined by numerical propagation using the nonlinear Schrodinger equation. Excellent switching of 95% can be achieved as a result of uniform phase characteristics developed by pulses propagating in the nonlinear amplifying loop mirror
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