6,633 research outputs found
Dynamics and transport properties of heavy fermions: theory
The paramagnetic phase of heavy fermion systems is investigated, using a
non-perturbative local moment approach to the asymmetric periodic Anderson
model within the framework of dynamical mean field theory. The natural focus is
on the strong coupling Kondo-lattice regime wherein single-particle spectra,
scattering rates, dc transport and optics are found to exhibit w/w_L,T/w_L
scaling in terms of a single underlying low-energy coherence scale w_L.
Dynamics/transport on all relevant (w,T)-scales are encompassed, from the
low-energy behaviour characteristic of the lattice coherent Fermi liquid,
through incoherent effective single-impurity physics likewise found to arise in
the universal scaling regime, to non-universal high-energy scales; and which
description in turn enables viable quantitative comparison to experiment.Comment: 27 pages, 12 figure
S-Matrix Poles Close to Thresholds in Confined Geometries
We have studied the behavior of the S-matrix poles near threshold for quantum
waveguides coupled to a cavity with a defect. We emphasize the occurrence of
both dominant and shadow poles on the various sheets of the energy Riemann
surface, and show that the changes of the total conductivity near threshold as
the cavity's width changes can be explained in terms of dominant to shadow pole
transitions.Comment: 10 pages, 5 figure
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The Divisive Power of Humour: Comedy, Taste and Symbolic Boundaries
Using British and Dutch interview data, this article demonstrates how people from different social classes draw strong symbolic boundaries on the basis of comedy taste. Eschewing the omnivorousness described in recent studies of cultural consumption, comedy audiences make negative aesthetic and moral judgements on the basis of comedy taste, and often make harsh judgements without the disclaimers, apologies and ambivalence so typical of ‘taste talk’ in contemporary culture. The article demonstrates how, in particular, Dutch and British middle class audiences use their comedy taste to communicate distinction and cultural superiority. We discuss several reasons why such processes of social distancing exist in comedy taste and not other cultural areas: the traditionally low status of comedy; the strong relation between humour and personhood; the continuity between comedy tastes and humour styles in everyday life; as well as the specific position of comedy in the British and Dutch cultural fields
Improved quantification of Chinese carbon fluxes using CO2/CO correlations in Asian outflow
[1] We use observed CO2:CO correlations in Asian outflow from the TRACE-P aircraft campaign (February–April 2001), together with a three-dimensional global chemical transport model (GEOS-CHEM), to constrain specific components of the east Asian CO2 budget including, in particular, Chinese emissions. The CO2/CO emission ratio varies with the source of CO2 (different combustion types versus the terrestrial biosphere) and provides a characteristic signature of source regions and source type. Observed CO2/CO correlation slopes in east Asian boundary layer outflow display distinct regional signatures ranging from 10–20 mol/mol (outflow from northeast China) to 80 mol/mol (over Japan). Model simulations using best a priori estimates of regional CO2 and CO sources from Streets et al. [2003] (anthropogenic), the CASA model (biospheric), and Duncan et al. [2003] (biomass burning) overestimate CO2 concentrations and CO2/CO slopes in the boundary layer outflow. Constraints from the CO2/CO slopes indicate that this must arise from an overestimate of the modeled regional net biospheric CO2 flux. Our corrected best estimate of the net biospheric source of CO2 from China for March–April 2001 is 3200 Gg C/d, which represents a 45 % reduction of the net flux from the CASA model. Previous analyses of the TRACE-P data had found that anthropogenic Chinese C
Ecological Effects of Fear: How Spatiotemporal Heterogeneity in Predation Risk Influences Mule Deer Access to Forage in a Sky‐Island System
Forage availability and predation risk interact to affect habitat use of ungulates across many biomes. Within sky‐island habitats of the Mojave Desert, increased availability of diverse forage and cover may provide ungulates with unique opportunities to extend nutrient uptake and/or to mitigate predation risk. We addressed whether habitat use and foraging patterns of female mule deer (Odocoileus hemionus) responded to normalized difference vegetation index (NDVI), NDVI rate of change (green‐up), or the occurrence of cougars (Puma concolor). Female mule deer used available green‐up primarily in spring, although growing vegetation was available during other seasons. Mule deer and cougar shared similar habitat all year, and our models indicated cougars had a consistent, negative effect on mule deer access to growing vegetation, particularly in summer when cougar occurrence became concentrated at higher elevations. A seemingly late parturition date coincided with diminishing NDVI during the lactation period. Sky‐island populations, rarely studied, provide the opportunity to determine how mule deer respond to growing foliage along steep elevation and vegetation gradients when trapped with their predators and seasonally limited by aridity. Our findings indicate that fear of predation may restrict access to the forage resources found in sky islands
Returns to the Jersey Fresh Promotional Program: The Impacts of Promotional Expenditures on Farm Cash Receipts in New Jersey
In 1984, the Jersey Fresh program was implemented by the New Jersey Department of Agriculture and was the first state-funded marketing campaign for agricultural products produced in New Jersey. In an effort to spur demand for New Jersey farm products, this program was designed to increase consumer awareness of the state’s agricultural products as well as to encourage food retailers to promote Jersey Fresh products. With funding from the USDA’s Federal-State Marketing Improvement Program, the New Jersey Department of Agriculture commissioned this study to determine the impact of Jersey Fresh promotion on farmer cash receipts in New Jersey. The econometric analysis was focused on the fruit and vegetable sectors, the primary commodity areas expected to benefit most directly from Jersey Fresh promotion. Study results show that: • For every dollar spent on the Jersey Fresh Promotional Program through 2000, New Jersey’s agricultural fruit and vegetable sector revenues increased by 22.95 of sales in agricultural support industries and other related industries. • In total, each dollar spent on Jersey Fresh promotion resulted in 1.16 million spent on the Jersey Fresh program in 2000 increased fruit and vegetable cash receipts by 26.6 million in economic activity within agricultural support industries. The total statewide economic impact of the Jersey Fresh program was therefore an estimated 2.2 million in 2000 due to the increased economic activity attributable to Jersey Fresh promotion. Comparing this return to the 2000 program budget of $1.16 million, the Jersey Fresh program appears to be better than revenue-neutral.Agribusiness, Marketing,
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Treatment of Alaska-produced food products by ionizing radiation may
benefit the seafood and agricultural industries and the Alaskan consumer. A
feasibility study to evaluate the potential social and economic benefits and
risks as well as the costs of using the process in Alaska on Alaskan products is being coordinated
by the Institute of Northern Engineering. A research and development project to determine
effects on the quality o f Alaskan products could be the next phase in the introduction o f a new
food-preservation technique
to Alaska
Out of equilibrium transport through an Anderson impurity: Probing scaling laws within the equation of motion approach
We study non-equilibrium electron transport through a quantum impurity
coupled to metallic leads using the equation of motion technique at finite
temperature T. Assuming that the interactions are taking place solely in the
impurity and focusing in the infinite Hubbard limit, we compute the out of
equilibrium density of states and the differential conductance G_2(T,V) to test
several scaling laws. We find that G_2(T,V)/G_2(T,0) is a universal function of
both eV/T_K and T/T_K, being T_K the Kondo temperature. The effect of an in
plane magnetic field on the splitting of the zero bias anomaly in the
differential conductance is also analyzed. For a Zeeman splitting \Delta, the
computed differential conductance peak splitting depends only on \Delta/T_K,
and for large fields approaches the value of 2\Delta . Besides the traditional
two leads setup, we also consider other configurations that mimics recent
experiments, namely, an impurity embedded in a mesoscopic wire and the presence
of a third weakly coupled lead. In these cases, a double peak structure of the
Kondo resonance is clearly obtained in the differential conductance while the
amplitude of the highest peak is shown to decrease as \ln(eV/T_K). Several
features of these results are in qualitative agreement with recent experimental
observations reported on quantum dots.Comment: 9 pages, 7 figure
Marine Monitoring Program: Annual report for inshore coral reef monitoring 2018–19
This project is supported by the Great Barrier Reef Marine Park Authority through funding from the Marine Monitoring Program, and the Australian Institute of Marine Science[Extract] This report details the condition of 31 inshore coral reefs monitored under the Great Barrier Reef Marine Park Authority’s Marine Monitoring Program and nine inshore coral reefs monitored by the Australian Institute of Marine Science’s Long-Term Monitoring Program. Results are presented in the context of the pressures faced by the ecosystem and their ramifications for the long-term health of inshore coral reefs
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