Kolmogorov-Burgers Model for Star Forming Turbulence

The process of star formation in interstellar molecular clouds is believed to be controlled by driven supersonic magnetohydrodynamic turbulence. We suggest that in the inertial range such turbulence obeys the Kolmogorov law, while in the dissipative range it behaves as Burgers turbulence developing shock singularities. On the base of the She-Leveque analytical model we then predict the velocity power spectrum in the inertial range to be E_k ~ k^{-1.74}. This result reproduces the observational Larson law, ~ l^{0.74...0.76}, [Larson, MNRAS 194 (1981) 809] and agrees well with recent numerical findings by Padoan and Nordlund [astro-ph/0011465]. The application of the model to more general dissipative structures, with higher fractal dimensionality, leads to better agreement with recent observational results.Comment: revised, new material added, 8 page

Time-temperature characteristics of thin- skinned models as affected by thermocouple variables Semiannual report

Time-temperature characteristics of thin skinned models as affected by thermocouple variable

Travelling to exotic places with cavity QED systems

Recent theoretical schemes for utilizing cavity QED models as quantum simulators are reviewed. By considering a quadrature representation for the fields, it is shown how Jahn-Teller models, effective Abelian or non-Abelian gauge potentials, transverse Hall currents, and relativistic effects naturally arise in these systems. Some of the analytical predictions are verified numerically using realistic experimental parameters taking into account for system losses. Thereby demonstrating their feasibility with current experimental setups.Comment: 5 pages, 3 figure

Cometary spectroscopy and imaging

The objective is to investigate the spectroscopic and morphological characteristics of comets and selected minor planets over a wide range of heliocentric distances as they may suggest or constrain models of cometary processes, their formation environments and evolution. Direct images of all observable comets and 300-800 nm spectra of the brighter ones are obtained on a monthly basis with a charge coupled device spectrograph-camera. The direct images may be used for astrometry, photometry, and studies of coma and tail morphology. In some cases, anisotropic dust emission can provide information on the nucleus spin vector. Spectra may provide data on strengths of the principle emission for comparison of gas/dust ratios of a large sample of comets. Long integrations of minor planets in comet-like and nearby orbits are made to search for faint comae

Terrorism on Trial: The President’s Constitutional Authority to Order the Prosecution of Suspected Terrorists by Military Commission

Sverige har sedan 1960-talet varit ett invandringsland. Av befolkningen är idag cirka 15 % födda i annat land. Andelen av befolkningen som är utlands-födda är i nivå med länder som USA och Tyskland. Andelen är inte bara betydligt högre än i övriga Nordiska länder, utan också högre än länder som Nederländerna, Frankrike och Storbritannien (RiR 2008:13).1 Utrikes födda beräknas utgöra en dryg fjärdedel av arbetskraftsreserven i Sverige. Under senare år har olika insatser genomförts med avsikt att öka arbetskraftsdelta-gandet

Estimating the Implicit Value of Crop Stubble as a Barrier to Technology Adoption in Morocco

For mixed cereal-livestock farmers, cereal production provides a bundle of goods. Grain is consumed by the household or sold at market, and crop residues are used as livestock feed. The straw component of crop residue can be bought and sold at market and therefore has a well-established local market price. Crop stubble, the portion of the crop residue left on the ground, is generally not traded and therefore has no market price. Some agricultural technologies require farmers to forgo using crop stubble as feed, and cultivation of high value crops entails sacrificing residue production altogether. In this paper we apply a structural econometric model to household data from Morocco to estimate the implicit value of crop stubble. We use a sample splitting technique to investigate differences in the value of this resource and find that it is significantly higher for smaller farmers, who therefore face an even larger barrier to technology adoption.Mixed cereal-livestock systems, Non-market valuation, Land use, Technology adoption, No-till, International Development, Land Economics/Use, Livestock Production/Industries, O33, Q12, Q24,

Asymmetric exclusion processes with constrained dynamics

Asymmetric exclusion processes with locally reversible kinetic constraints are introduced to investigate the effect of non-conservative driving forces in athermal systems. At high density they generally exhibit rheological-like behavior, negative differential resistance, two-step structural relaxation, dynamical heterogeneity and, possibly, a jamming transition driven by the external field.Comment: 4 pages, 4 figures; revised version: minor changes, added references; to be publishe

Public Economic Benefits of Reducing Salinity Discharges: Evidence from California’s San Joaquin Valley

Environmental Economics and Policy,