2,312 research outputs found
Weekday Religious Instruction in the Public Schools of Omaha, Nebraska
The investigation to be reported was undertaken in an effort to determine why the release-time religious education in the Omaha public schools through so-called Weekday Church Schools was discontinued after one year of operation. The promoters of the project reported that hardly a more favorable situation for Weekday Church Schools could have been found and yet it had to be abandoned because of lack of funds
Vapor feeding of liquid metal cathodes
Modified liquid metal cathode apparatus permits vapor feeding in the diffuse-spot pattern mode. Vapor-fed cathode has advantages over liquid-fed systems
High-temperature LM cathode ion thrusters Quarterly progress report, 5 May - 4 Aug. 1968
Design and operation of high temperature liquid mercury cathode ion thruster
High-temperature LM cathode ion thrusters Quarterly progress report, 5 Feb. - 4 May 1968
Poiseuille flow measurements for high temperature liquid metal cathode ion thruster
High-temperature liquid-mercury cathodes for ion thrusters Quarterly progress report, 1 Dec. 1966 - 28 Feb. 1967
High temperature liquid mercury cathodes for ion thrusters - thermal design analysi
Suggestions for Better Integrating ICT enhanced
In: A.J. Kallenberg and M.J.J.M. van de Ven (Eds), 2002, The New Educational Benefits of ICT in Higher Education: Proceedings. Rotterdam: Erasmus Plus BV, OECR
ISBN 90-9016127-9The particular situation of academic teachers and learners in campus-based Higher Education today gives rise to the idea of an integrated dimensional framework for instructional design (ID). We will relate it to the potential of ICT, especially for blended learning. It is argued that the framework can become the kernel of an advisory system addressing current needs of practitioners in campus-based Higher Education by taking advantage of research evidence
Tidal controls on trace gas dynamics in a seagrass meadow of the Ria Formosa lagoon (southern Portugal)
Coastal zones are important source regions for a variety of trace gases, including halocarbons and sulfur-bearing species. While salt marshes, macroalgae and phyto-plankton communities have been intensively studied, little is known about trace gas fluxes in seagrass meadows. Here we report results of a newly developed dynamic flux chamber system that can be deployed in intertidal areas over full tidal cycles allowing for highly time-resolved measurements. The fluxes of CO2, methane (CH4) and a range of volatile organic compounds (VOCs) showed a complex dynamic mediated by tide and light. In contrast to most previous studies, our data indicate significantly enhanced fluxes during tidal immersion relative to periods of air exposure. Short emission peaks occurred with onset of the feeder current at the sampling site. We suggest an overall strong effect of advective transport processes to explain the elevated fluxes during tidal immersion. Many emission estimates from tidally influenced coastal areas still rely on measurements carried out during low tide only. Hence, our results may have significant implications for budgeting trace gases in coastal areas. This dynamic flux chamber system provides intensive time series data of community respiration (at night) and net community production (during the day) of shallow coastal systems.German Federal Ministry of Education and Research (BMBF) [03F0611E, 03F0662E]; EU FP7 ASSEMBLE research infrastructure initiative
Statistical analysis of coherent structures in transitional pipe flow
Numerical and experimental studies of transitional pipe flow have shown the
prevalence of coherent flow structures that are dominated by downstream
vortices. They attract special attention because they contribute predominantly
to the increase of the Reynolds stresses in turbulent flow. In the present
study we introduce a convenient detector for these coherent states, calculate
the fraction of time the structures appear in the flow, and present a Markov
model for the transition between the structures. The fraction of states that
show vortical structures exceeds 24% for a Reynolds number of about Re=2200,
and it decreases to about 20% for Re=2500. The Markov model for the transition
between these states is in good agreement with the observed fraction of states,
and in reasonable agreement with the prediction for their persistence. It
provides insight into dominant qualitative changes of the flow when increasing
the Reynolds number.Comment: 11 pages, 26 (sub)figure
Liquid mercury cathode electron bombardment ion thrusters Summary report, 1 Aug. 1964 - 31 Oct. 1966
Life tests of liquid mercury cathodes for electron bombardment ion thruster
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