88,340 research outputs found
Small cities for a small country: Sustaining the cultural renaissance?
Copyright @ 2006 RoutledgeThis chapter explores the implications for smaller cities of adopting culture-led
regeneration strategies. It is suggested that there is a divergence between cultural
planning for long term sustainable urban cultural renaissance and culture-led
makeovers which rely on externally orientated projects devised to draw in new
visitors, residents and enterprises. Drawing on evidence from Sheffield, an industrial
city in South Yorkshire, northern England, it is suggested that small cities by thinking
big, have been seduced into entering a culture-led city competition in which the
stakes are high and the prospects of success limited
Rich mix cities: From multicultural experience to cosmopolitan engagement
Copyright @ 2004 Museum Tusculanum Press and ScanOC
Method and apparatus for mapping the distribution of chemical elements in an extended medium
Contaminants in an extended medium such as the wall of a building are mapped by locating neutron excitation source on one side of the wall and a gamma ray spectrometer, including a gamma ray detector on the opposite side of the wall facing the excitation source. The source and detector are moved in unison in discrete steps over opposing wall surfaces so as to determine the chemical composition of the elements in a hemispheric region of the wall adjacent the detector with the radius of the region being substantially that of the mean free path distance of gamma rays emitted from elements interacting with neutrons on the detector side of the wall. The source and detector are reversed for relatively thick walls for mapping the distribution of elements on the other side of the wall thickness. The output of the detector is fed to a multichannel pulse height analyzer where the intensity of the various gamma ray spectral lines are indicated relative to a dominant constituent element such as silicon. Resolution of anomalies such as the presence of voids and/or determining the bulk density of the medium is achieved by substituting a gamma ray source technique is also applied to metal alloys, such as iron alloys, in either the solid or molten state
An overview of aerospace gas turbine technology of relevance to the development of the automotive gas turbine engine
Technology areas related to gas turbine propulsion systems with potential for application to the automotive gas turbine engine are discussed. Areas included are: system steady-state and transient performance prediction techniques, compressor and turbine design and performance prediction programs and effects of geometry, combustor technology and advanced concepts, and ceramic coatings and materials technology
2D and 3D Dense-Fluid Shear Flows via Nonequilibrium Molecular Dynamics. Comparison of Time-and-Space-Averaged Tensor Temperature and Normal Stresses from Doll's, Sllod, and Boundary-Driven Shear Algorithms
Homogeneous shear flows (with constant strainrate du/dy) are generated with
the Doll's and Sllod algorithms and compared to corresponding inhomogeneous
boundary-driven flows. We use one-, two-, and three-dimensional smooth-particle
weight functions for computing instantaneous spatial averages. The nonlinear
stress differences are small, but significant, in both two and three space
dimensions. In homogeneous systems the sign and magnitude of the shearplane
stress difference, P(xx) - P(yy), depend on both the thermostat type and the
chosen shearflow algorithm. The Doll's and Sllod algorithms predict opposite
signs for this stress difference, with the Sllod approach definitely wrong, but
somewhat closer to the (boundary-driven) truth. Neither of the homogeneous
shear algorithms predicts the correct ordering of the kinetic temperatures,
T(xx) > T(zz) > T(yy).Comment: 34 pages with 12 figures, under consideration by Physical Review
Variable geometry aft-fan for takeoff quieting or thrust augmentation of a turbojet engine
A concept is presented that combines the low-noise and high-thrust characteristics of a turbofan at takeoff, together with its high efficiency at subsonic flight speeds, with the high efficiency of a turbojet at supersonic cruise. It consists of a free turbine with tip fan mounted behind the turbine of a conventional turbojet engine. Fan air is supplied from blow-in doors or is ducted from the main engine inlet. At high flight speeds where fan augmentation is not desirable, the fan inlet is closed and the free turbine is stopped by adjustment of its variable-camber stators. Estimates of noise, cycle performance, and example configurations are presented for a typical supersonic transport application
Nonequilibrium, thermostats and thermodynamic limit
The relation between thermostats of "isoenergetic" and "frictionless" kind is
studied and their equivalence in the thermodynamic limit is proved in space
dimension and, for special geometries, .Comment: 22 pages PRA 2-columns format v3: Typos corrected as acknowledge
Solvent mediated interactions between model colloids and interfaces: A microscopic approach
We determine the solvent mediated contribution to the effective potentials
for model colloidal or nano- particles dispersed in a binary solvent that
exhibits fluid-fluid phase separation. Using a simple density functional theory
we calculate the density profiles of both solvent species in the presence of
the `colloids', which are treated as external potentials, and determine the
solvent mediated (SM) potentials. Specifically, we calculate SM potentials
between (i) two colloids, (ii) a colloid and a planar fluid-fluid interface,
and (iii) a colloid and a planar wall with an adsorbed wetting film. We
consider three different types of colloidal particles: colloid A which prefers
the bulk solvent phase rich in species 2, colloid C which prefers the solvent
phase rich in species 1, and `neutral' colloid B which has no strong preference
for either phase, i.e. the free energies to insert the colloid into either of
the coexisting bulk phases are almost equal. When a colloid which has a
preference for one of the two solvent phases is inserted into the disfavored
phase at statepoints close to coexistence a thick adsorbed `wetting' film of
the preferred phase may form around the colloids. The presence of the adsorbed
film has a profound influence on the form of the SM potentials.Comment: 17 Pages, 13 Figures. Accepted for publication in Journal of Chemical
Physic
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