38,674 research outputs found
Method for observing the features characterizing the surface of a land mass
A method is described where a propeller driven, hydrazine powered aircraft is remotely piloted through rarefied atmosphere of a selected planet, including the planet Earth. It is employed as a communication platform for a telemetry system provided for relaying information relating to features characterizing the surface of the planet
Point interactions in acoustics: one dimensional models
A one dimensional system made up of a compressible fluid and several
mechanical oscillators, coupled to the acoustic field in the fluid, is analyzed
for different settings of the oscillators array. The dynamical models are
formulated in terms of singular perturbations of the decoupled dynamics of the
acoustic field and the mechanical oscillators. Detailed spectral properties of
the generators of the dynamics are given for each model we consider. In the
case of a periodic array of mechanical oscillators it is shown that the energy
spectrum presents a band structure.Comment: revised version, 30 pages, 2 figure
Simultaneous assessment of CO2 sensitivity in the respiratory network and its neurons
This work was funded by the National Science Foundation IOS-1 022442
Evaluative criteria for health education at the elementary school level
Thesis (Ed.M.)--Boston Universit
Application of the method local potential to the analysis of turbulent shear flows
It has been found that, in general, the local potential cannot be employed to obtain approximate solutions for the various correlations of turbulent properties which appear in the time averaged form of the conservation equations. Although the method of local potential is equivalent to the Galerkin method when the self-consistent condition is applied, the local potential can also be applied as an iterative algorithm in place of using the selfconsistent condition. This procedure offers an alternative to the Galerkin method and may be useful in obtaining approximate solutions for the total turbulent velocity. In addition, for certain simple turbulent shear flows the iterative algorithm may permit approximate, but non-empirical, solutions by modeling only the mean velocity and the Reynolds stress
Small hydrogen/oxygen rocket flowfield behavior from heat flux measurements
The mixing and heat transfer phenomena in small rocket flow fields with fuel film cooling is not well understood. An instrumented, water-cooled chamber with a gaseous hydrogen/gaseous oxygen injector was used to gather steady-state inner and outer wall temperature profiles. The chamber was tested at 414 kPa (60 psia) chamber pressure, from mixture ratios of 3.41 to 8.36. Sixty percent of the fuel was used for film cooling. These temperature profiles were used as boundary conditions in a finite element analysis program, MSC/NASTRAN, to calculate the local radial and axial heat fluxes in the chamber wall. The normal heat fluxes were then calculated and used as a diagnostic of the rocket's flow field behavior. The normal heat fluxes determined were on the order of 1.0 to 3.0 MW/meters squared (0.6 to 1.8 Btu/sec-inches squared). In the cases where mixture ratio was 5 or above, there was a sharp local heat flux maximum in the barrel section of the chamber. This local maximum seems to indicate a reduction or breakdown of the fuel film cooling layer, possibly due to increased mixing in the shear layer between the film and core flows. However, the flow was thought to be completely laminar, as the throat Reynolds numbers were below 50,000 for all the cases. The increased mixing in the shear layer in the higher mixture ratio cases appeared not to be due to the transition of the flow from laminar to turbulent, but rather due to increased reactions between the hydrogen film and oxidizer-rich core flows
A Model for Multilevel Advocacy Evaluation
· The Colorado Trust provided three years of general operating support to nine advocacy organizations working to increase access to health through policy change work.
· The nine grantees had a variety of goals and strategies and had different levels of organizational capacity, but were evaluated using a uniform evaluation approach.
· The evaluation was designed to build grantees’ own evaluation capacity to incorporate real-time feedback, monitor progress toward goals, and to assess growth in the overall health advocacy community in Colorado.
· Individual grantees identified short- and intermediate- term outcomes related to The Trust’s intermediate outcomes, which were in turn related to the long-term outcomes developed by The Trust and the grantees.
· Challenges include aligning outcomes across levels, defining the baseline of the current “health advocacy community,” and identifying the time involved in managing the multitiered data collection effort
High power-high voltage waterload Patent
Variable water load for dissipating large amounts of electrical power during high voltage power supply test
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