1,785 research outputs found
Vibration effects on heat transfer in cryogenic systems Quarterly progress report, Jul. 1 - Sep. 30, 1967
Water test apparatus used to determine vibration effects on heat transfer in cryogenic system
Ground State H-Atom in Born-Infeld Theory
Within the context of Born-Infeld (BI) nonlinear electrodynamics (NED) we
revisit the non-relativistic, spinless H-atom. The pair potential computed from
the Born-Infeld equations is approximated by the Morse type potential with
remarkable fit over the critical region where the convergence of both the short
and long distance expansions slows down dramatically. The Morse potential is
employed to determine both the ground state energy of the electron and the BI
parameter.Comment: 4 pages, 1 figure, final version to appear in Foundation of Physic
Nonperturbative calculation of Born-Infeld effects on the Schroedinger spectrum of the hydrogen atom
We present the first nonperturbative numerical calculations of the
nonrelativistic hydrogen spectrum as predicted by first-quantized
electrodynamics with nonlinear Maxwell-Born-Infeld field equations. We also
show rigorous upper and lower bounds on the ground state.
When judged against empirical data our results significantly restrict the
range of viable values of the new electromagnetic constant which is introduced
by the Born-Infeld theory.
We assess Born's own proposal for the value of his constant.Comment: 4p., 2 figs, 1 table; submitted for publicatio
Observations of Low Frequency Solar Radio Bursts from the Rosse Solar-Terrestrial Observatory
The Rosse Solar-Terrestrial Observatory (RSTO; www.rosseobservatory.ie) was
established at Birr Castle, Co. Offaly, Ireland (53 05'38.9", 7 55'12.7") in
2010 to study solar radio bursts and the response of the Earth's ionosphere and
geomagnetic field. To date, three Compound Astronomical Low-cost Low-frequency
Instrument for Spectroscopy and Transportable Observatory (CALLISTO)
spectrometers have been installed, with the capability of observing in the
frequency range 10-870 MHz. The receivers are fed simultaneously by biconical
and log-periodic antennas. Nominally, frequency spectra in the range 10-400 MHz
are obtained with 4 sweeps per second over 600 channels. Here, we describe the
RSTO solar radio spectrometer set-up, and present dynamic spectra of a sample
of Type II, III and IV radio bursts. In particular, we describe fine-scale
structure observed in Type II bursts, including band splitting and rapidly
varying herringbone features
Mind the gap? The persistence of pathological discourses in urban regeneration policy
Urban regeneration policy has historically framed policy problems using a discourse that pathologises areas and spatial communities. Since 2001 in England, and 2002 in Scotland a structural change in policy has occurred where citywide partnerships are now meant overcome structural spatial inequalities, countering pathological explanations. This paper uses historical and discourse analysis to evaluate one of the major community regeneration strategies developed by the Scottish Executive in 2002: Better Communities in Scotland: Closing the Gap. It seeks to ask whether structural change in policy was paralleled by discursive change; what discursive path dependence is evidenced? The text is placed in the historic context of UK urban renewal policies dating back to the launch of the Urban Programme in 1968 and particularly the policy discourse created by the influential Conservative government policy of 1988 New Life for Urban Scotland and the wider discourses of poverty and neighbourhood renewal policy created by Labour governments since 1997. The close textual analysis of the text shows that Better Communities in Scotland continues to pathologise spatial communities. Although this suggests a degree of historical path dependency, the historic breadth of the analysis also problematises simple historical determinism
A Dynamic Knowledge Management Framework for the High Value Manufacturing Industry
Dynamic Knowledge Management (KM) is a combination of cultural and technological factors, including the cultural factors of people and their motivations, technological factors of content and infrastructure and, where these both come together, interface factors. In this paper a Dynamic KM framework is described in the context of employees being motivated to create profit for their company through product development in high value manufacturing. It is reported how the framework was discussed during a meeting of the collaborating company’s (BAE Systems) project stakeholders. Participants agreed the framework would have most benefit at the start of the product lifecycle before key decisions were made. The framework has been designed to support organisational learning and to reward employees that improve the position of the company in the market place
A Cognitive Model of an Epistemic Community: Mapping the Dynamics of Shallow Lake Ecosystems
We used fuzzy cognitive mapping (FCM) to develop a generic shallow lake
ecosystem model by augmenting the individual cognitive maps drawn by 8
scientists working in the area of shallow lake ecology. We calculated graph
theoretical indices of the individual cognitive maps and the collective
cognitive map produced by augmentation. The graph theoretical indices revealed
internal cycles showing non-linear dynamics in the shallow lake ecosystem. The
ecological processes were organized democratically without a top-down
hierarchical structure. The steady state condition of the generic model was a
characteristic turbid shallow lake ecosystem since there were no dynamic
environmental changes that could cause shifts between a turbid and a clearwater
state, and the generic model indicated that only a dynamic disturbance regime
could maintain the clearwater state. The model developed herein captured the
empirical behavior of shallow lakes, and contained the basic model of the
Alternative Stable States Theory. In addition, our model expanded the basic
model by quantifying the relative effects of connections and by extending it.
In our expanded model we ran 4 simulations: harvesting submerged plants,
nutrient reduction, fish removal without nutrient reduction, and
biomanipulation. Only biomanipulation, which included fish removal and nutrient
reduction, had the potential to shift the turbid state into clearwater state.
The structure and relationships in the generic model as well as the outcomes of
the management simulations were supported by actual field studies in shallow
lake ecosystems. Thus, fuzzy cognitive mapping methodology enabled us to
understand the complex structure of shallow lake ecosystems as a whole and
obtain a valid generic model based on tacit knowledge of experts in the field.Comment: 24 pages, 5 Figure
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