Temperature dependence of the breakdown of the quantum Hall effect studied by induced currents

Copyright © 2004 The American Physical SocietyWe have developed a model of the high-current breakdown of the integer quantum Hall effect, as measured in contactless experiments using a highly-sensitive torsion balance magnetometer. The model predicts that, for empirically “low-mobility” samples (μ<75 m2 V−1 s−1), the critical current for breakdown should decrease with, and have a linear dependence on, temperature. This prediction is verified experimentally with the addition of a low-temperature saturation of the critical current at a temperature that depends on both sample number density and filling factor. It is shown that this saturation is consistent with quasielastic inter-Landau-level scattering when the maximum electric field in the sample reaches a large enough value. In addition we show how this model can be extended to give qualitative agreement with experiments on high-mobility samples

γ -soft Ba 146 and the role of nonaxial shapes at N≈90

Low-spin states in the neutron-rich, N=90 nuclide Ba146 were populated following β decay of Cs146, with the goal of clarifying the development of deformation in barium isotopes through delineation of their nonyrast structures. Fission fragments of Cs146 were extracted from a 1.7-Ci Cf252 source and mass selected using the CAlifornium Rare Ion Breeder Upgrade (CARIBU) facility. Low-energy ions were deposited at the center of a box of thin β detectors, surrounded by a highly efficient high-purity Ge array. The new Ba146 decay scheme now contains 31 excited levels extending up to ∼2.5 MeV excitation energy, double what was previously known. These data are compared to predictions from the interacting boson approximation (IBA) model. It appears that the abrupt shape change found at N=90 in Sm and Gd is much more gradual in Ba and Ce, due to an enhanced role of the γ degree of freedom

Nutrition of the sow

SIGLEAvailable from British Library Document Supply Centre- DSC:D74636/87 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Loyalty and dissidence in Roman Egypt The case of the Acta Alexandrinorum

Available from British Library Document Supply Centre-DSC:DXN047918 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Substance abuse trends in the Western Cape: a review of studies conducted since 2000

Commissioned by the Department of Social Development, Cape TownA consortium of researchers from the South African Medical Research Council, Human Sciences Research Council, University of Cape Town and Dopstop was established to identify, summarise and integrate findings from substance abuse research conducted in the province over the last eight years. A review of research conducted since 2000 was done and compiled into a summary report of key findings on substance abuse trends in the Western Cape. The report provides recommendations for interventions and outlines gaps in current knowledge that will assist the Department of Social Development in identifying research needs and service planning. This report reveals that alcohol remains a significant substance of abuse in the Western Cape. Alcohol abuse is often not a key focal point for prevention and treatment services and yet places a tremendous burden on the health and social welfare sectors in both urban and rural areas of the province. Effective interventions that address alcohol use among all race and gender groups are hence required. This report also highlights the growing use of stimulants in the province (such as methamphetamine and cocaine). Stimulant abuse is associated with a myriad of problems, especially sexual risk behaviour. Effective interventions for treating stimulant-related problems are urgently required in the province. Stimulants are also not used in isolation. This report highlights the use of other classes of drugs, such as opiates, cannabis and sedatives to come down from a stimulant-induced high. These drugs pose their own set of health and social problems. In summary, these findings show that no single substance should be viewed in isolation. Substance abuse services should therefore focus on preventing and treating poly-substance use. This report identifies several gaps in current knowledge on substance use in the province. Given the scale of the substance abuse problem in the Western Cape, funding for research on substance use has been limited. A comprehensive research strategy that includes a province-wide, dedicated household survey focused on substance abuse; continued support for the SACENDU and district social services surveillance systems; regular school-based surveys; and ongoing intervention research is required. Together, this research will provide the DOSD with up to date information on the prevalence of substance use disorders in the province, changing patterns of substance use, geographical areas where treatment and prevention needs are greatest, and data on substance use in remote and rural areas of the province. To ensure that this strategy is successfully implemented, adequate funding should be ear-marked for these initiatives. This report also emphasises the need for intervention research to develop effective means of preventing and treating the harms associated with substance use, particularly substance-related injuries and substance related sexual risks. This intervention research should also focus on establishing the cost-effectiveness, efficiency and effectiveness of current prevention and treatment services in the province. Intervention services are also needed to address substance abuse among vulnerable populations, such as rural and Black/African communities and among women