Phase fluctuations and Non-Fermi Liquid Properties of 2D Fermi-system with attraction

The effect of static fluctuations in the phase of the order parameter on the normal and superconducting properties of a 2D system with attractive four-fermion interaction has been studied. Analytic expressions for the fermion Green function, its spectral density and the density of states are derived. The resultant single-particle Green function clearly demonstrates non-Fermi liquid behavior. The results show that as the temperature increases through the 2D critical temperature the width of the quasiparticle peaks broadens significantly. At the same time one retains the gap in quasiparticle spectrum. The spectral density for the dynamical fluctuations can also be obtained. Clearly the dynamical fluctuations fill the gap giving the observed pseudogap behaviour.Comment: 4 pages, LaTeX; invited paper presented at New^3SC-2, Las Vegas, USA, 199

Moral Leadership: A Model for Educational Leaders in the 21st Century

Furthering the understanding of and exploring the literature on moral leadership models is the purpose of this research paper. A review the literature was undertaken, synthesizing concepts and offering a new paradigm for educational leaders

Lattice Architecture

The pervasive proliferation of complex tracking systems such as GPS and simulation gaming environments such as Full Spectrum Warrior are transforming the built environment into an immersive 1:1 map where all flows and transactions are measured, monitored, and tracked. The gap between map and real experience disappears resulting in an immersive map. The spatial implications of this real time 1:1 immersive map creates an opportunity for architecture itself to monitor, track, and measure flows and transactions. This tracking and simulation agenda plays out specifically in the design of a surface that integrates military training, military artifacts, and civilian recreation into the MIL_CIV surface that modulates due to games, time of day, season, and participants acting on the site

MIL_CIV Immersive Surface

The pervasive proliferation of complex tracking systems such as GPS and simulation gaming environments such as Full Spectrum Warrior are transforming the built environment into an immersive 1:1 map where all flows and transactions are measured, monitored, and tracked. The gap between map and real experience disappears resulting in an immersive map. The spatial implications of this real time 1:1 immersive map creates an opportunity for architecture itself to monitor, track, and measure flows and transactions. This tracking and simulation agenda plays out specifically in the design of a surface that integrates military training, military artifacts, and civilian recreation into the MIL_CIV surface that modulates due to games, time of day, season, and participants acting on the site

Book Review: Who Needs It: A Review of Instant Art Instant Culture

Book review for Instant Art Instant Culture: The Unspoken Policy for American Schools, Laura Chapman, Teachers College Press, New York, 1982

Pseudogap phase formation in the crossover from Bose-Einstein condensation to BCS superconductivity in low dimensional systems

A phase diagram for a 2D metal with variable carrier density has been studied using the modulus-phase representation for the order parameter in a fully microscopic treatment. This amounts to splitting the degrees of freedom into neutral fermion and charged boson degrees of freedom. Although true long range order is forbidden in two dimensions, long range order for the neutral fermions is possible since this does not violate any continuous symmetry. The phase fluctuations associated with the charged degrees of freedom destroy long range order in the full system as expected. The presence of the neutral order parameter gives rise to new features in the superconducting condensate formation in low dimensional systems. The resulting phase diagram contains a new phase which lies above the superconducting (here Berezinskii-Kosterlitz-Thouless) phase and below the normal (Fermi-liquid) phase. We identify this phase with the pseudogap phase observed in underdoped high-$T_{c}$ superconducting compounds above their critical temperature. We also find that the phase diagram persists even in the presence of weak 3-dimensionalisation.Comment: 4 pages, LaTeX; invited paper presented at New^3SC-1, Baton Rouge, USA, 1998. To be published in Int.J.Mod.Phys.

Global coverage of cetacean line-transect surveys : status quo, data gaps and future challenges

Knowledge of abundance, trends and distribution of cetacean populations is needed to inform marine conservation efforts, ecosystem models and spatial planning. We compiled a geo-spatial database of published data on cetacean abundance from dedicated visual line-transect surveys and encoded >1100 abundance estimates for 47 species from 430 surveys conducted worldwide from 1975-2005. Our subsequent analyses revealed large spatial, temporal and taxonomic variability and gaps in survey coverage. With the exception of Antarctic waters, survey coverage was biased toward the northern hemisphere, especially US and northern European waters. Overall, <25% of the world’s ocean surface was surveyed and only 6% had been covered frequently enough (≥ 5 times) to allow trend estimation. Almost half the global survey effort, defined as total area (km2) covered by all survey study areas across time, was concentrated in the Eastern Tropical Pacific (ETP). Neither the number of surveys conducted nor the survey effort had increased in recent years. Across species, an average of 10% of a species’ predicted range had been covered by at least one survey, but there was considerable variation among species. With the exception of three delphinid species, <1% of all species’ ranges had been covered frequently enough for trend analysis. We use a data-rich species, sperm whale, as an example to illustrate the challenges of using available data from line-transect surveys for the detection of trends or for spatial planning. Finally, we propose and contrast several field and analytical methods to fill in data gaps to improve future cetacean conservation management efforts.Publisher PDFPeer reviewe