The natural resources of Carpinteria Marsh: their status and future

The purpose of this report is: 1) to document the natural resources of Carpinteria Marsh, 2) outline the uses those resources receive, 3) enumerate the problems and conflicts of use that affect those resources, and 4) recommend measures that will protect and enhance the marsh and its resources. It is intended as a guide for citizens, planners and administrators of all private and public entities interested in the status and future of the marsh. This report has been prepared under contract to and fully funded by the Office of Biological Services of the U.S. Fish and Wildlife Service. The goals and purpose of this federal office are to review the impact on fish and wildlife resources of land, mineral and water development practices, such as offshore oil and gas exploration, development and production; construction of inshore pipeline canals and refineries; power plant construction/operation and urban development. This report, and five other southern California reports, covering Agua Hedionda (San Diego County), Anaheim Bay-Huntington Harbor (Orange County), Mugu Lagoon (Ventura County), the Northern Santa Barbara County Coastal Wetlands and the Nipomo Dunes and Wetlands (San Luis Obispo County), are scheduled to be part of the Department's "Coastal Wetland Series" that includes reports on the natural resources of Upper Newport Bay (Orange County), Goleta Slough (Santa Barbara county), Bolinas Lagoon (Marin County), Elkhorn Slough (Monterey County), San Diego Bay and Los Penasquitos Lagoon (San Diego County), Morro Bay (San Luis Obispo County), Humboldt Bay and the Eel River Delta (Humboldt County), Lake Earl and the Smith River Delta (Del Norte County) and Bodega Harbor (Sonoma County). (103pp.

Composition and Origins of Polycyclic Aromatic Hydrocarbons in the Mackenzie River and on the Beaufort Sea Shelf

Polycyclic aromatic hydrocarbon (PAH) concentrations in suspended particulate samples from the Mackenzie River delta and shelf sediments from the Beaufort Sea are higher than expected for a pristine area. Low concentrations of combustion PAHs indicate that anthropogenic inputs are low. Alkyl PAH distributions indicate that a significant component of the lower molecular weight parent (unsubstituted) PAH fraction is petrogenic. The majority of the high molecular weight PAHs, together with the petrogenic PAHs, have a principal source in the Mackenzie River. Despite the high PAH content, we consider the area still to be pristine. Although PAH concentrations are below the concentrations believed to induce toxic effects on biota, the high natural concentrations may make this region of the Arctic sensitive to additional PAHs from human activities.Key words: polycyclic aromatic hydrocarbon (PAH), Arctic, baseline, sediment, effects threshold, principal components analysisLes concentrations d'hydrocarbures aromatiques polycycliques (HAP) dans des échantillons de particules en suspension venant du delta du Mackenzie et de sédiments du plateau continental de la mer de Beaufort sont plus élevées qu'on pourrait s'y attendre pour une zone vierge. Les faibles concentrations de HAP de combustion suggèrent que l'apport anthropique est faible. La distribution des HAP alkyles indique qu'une composante importante de la fraction de HAP-mère (non substitué) à bas poids moléculaire est pétrogénétique. La majorité des HAP à haut poids moléculaire, ainsi que les HAP pétrogénétiques, ont leur source principale dans le fleuve Mackenzie. Malgré la teneur élevée en HAP, la région est toujours considérée comme vierge. Bien que les concentrations d'HAP soient inférieures aux valeurs qui pourraient avoir des effets toxiques sur le biote, les fortes concentrations naturelles peuvent rendre cette région de l'Arctique sensible aux HAP supplémentaires venant des activités humaines.Mots clés: hydrocarbure aromatique polycyclique (HAP), Arctique, données de base, sédiment, seuil des effets, analyse des principaux composant

Improved position measurement of nano electromechanical systems using cross correlations

We consider position measurements using the cross-correlated output of two tunnel junction position detectors. Using a fully quantum treatment, we calculate the equation of motion for the density matrix of the coupled detector-detector-mechanical oscillator system. After discussing the presence of a bound on the peak-to-background ratio in a position measurement using a single detector, we show how one can use detector cross correlations to overcome this bound. We analyze two different possible experimental realizations of the cross correlation measurement and show that in both cases the maximum cross-correlated output is obtained when using twin detectors and applying equal bias to each tunnel junction. Furthermore, we show how the double-detector setup can be exploited to drastically reduce the added displacement noise of the oscillator.Comment: 9 pages, 1 figure; v2: new Sec.

Electrical transport through a single-electron transistor strongly coupled to an oscillator

We investigate electrical transport through a single-electron transistor coupled to a nanomechanical oscillator. Using a combination of a master-equation approach and a numerical Monte Carlo method, we calculate the average current and the current noise in the strong-coupling regime, studying deviations from previously derived analytic results valid in the limit of weak-coupling. After generalizing the weak-coupling theory to enable the calculation of higher cumulants of the current, we use our numerical approach to study how the third cumulant is affected in the strong-coupling regime. In this case, we find an interesting crossover between a weak-coupling transport regime where the third cumulant heavily depends on the frequency of the oscillator to one where it becomes practically independent of this parameter. Finally, we study the spectrum of the transport noise and show that the two peaks found in the weak-coupling limit merge on increasing the coupling strength. Our calculation of the frequency-dependence of the noise also allows to describe how transport-induced damping of the mechanical oscillations is affected in the strong-coupling regime.Comment: 11 pages, 9 figure

Membrane paradigm and entropy of black holes in the Euclidean action approach

The membrane paradigm approach to black holes fixes in the vicinity of the event horizon a fictitious surface, the stretched horizon, so that the spacetime outside remains unchanged and the spacetime inside is vacuum. Using this powerful method, several black hole properties have been found and settled, such as the horizon's viscosity, electrical conductivity, resistivity, as well as other properties. On the other hand the Euclidean action approach to black hole spacetimes has been very fruitful in understanding black hole entropy. Combining both the Euclidean action and membrane paradigm approaches a direct derivation of the black hole entropy is given. In the derivation it is considered that the only fields present are the gravitational and matter fields, with no electric field.Comment: 13 page

On the Conductance Sum Rule for the Hierarchical Edge States of the Fractional Quantum Hall Effect

The conductance sum rule for the hierarchical edge channel currents of a Fractional Quantum Hall Effect state is derived analytically within the Haldane-Halperin hierarchy scheme. We provide also an intuitive interpretation for the hierarchical drift velocities of the edge excitations.Comment: 11 pages, no figure, Revtex 3.0, IC/93/329, ASITP-93-5

Collective excitations in double-layer quantum Hall systems

We study the collective excitation spectra of double-layer quantum-Hall systems using the single mode approximation. The double-layer in-phase density excitations are similar to those of a single-layer system. For out-of-phase density excitations, however, both inter-Landau-level and intra-Landau-level double-layer modes have finite dipole oscillator strengths. The oscillator strengths at long wavelengths for the latter transitions are shifted upward by interactions by identical amounts proportional to the interlayer Coulomb coupling. The intra-Landau-level out-of-phase mode has a gap when the ground state is incompressible except in the presence of spontaneous inter-layer coherence. We compare our results with predictions based on the Chern-Simons-Landau-Ginzburg theory for double-layer quantum Hall systems.Comment: RevTeX, 21 page

An interacting spin flip model for one-dimensional proton conduction

A discrete asymmetric exclusion process (ASEP) is developed to model proton conduction along one-dimensional water wires. Each lattice site represents a water molecule that can be in only one of three states; protonated, left-pointing, and right-pointing. Only a right(left)-pointing water can accept a proton from its left(right). Results of asymptotic mean field analysis and Monte-Carlo simulations for the three-species, open boundary exclusion model are presented and compared. The mean field results for the steady-state proton current suggest a number of regimes analogous to the low and maximal current phases found in the single species ASEP [B. Derrida, Physics Reports, {\bf 301}, 65-83, (1998)]. We find that the mean field results are accurate (compared with lattice Monte-Carlo simulations) only in the certain regimes. Refinements and extensions including more elaborate forces and pore defects are also discussed.Comment: 13pp, 6 fig

Rate of convergence of linear functions on the unitary group

We study the rate of convergence to a normal random variable of the real and imaginary parts of Tr(AU), where U is an N x N random unitary matrix and A is a deterministic complex matrix. We show that the rate of convergence is O(N^{-2 + b}), with 0 <= b < 1, depending only on the asymptotic behaviour of the singular values of A; for example, if the singular values are non-degenerate, different from zero and O(1) as N -> infinity, then b=0. The proof uses a Berry-Esse'en inequality for linear combinations of eigenvalues of random unitary, matrices, and so appropriate for strongly dependent random variables.Comment: 34 pages, 1 figure; corrected typos, added remark 3.3, added 3 reference