Fermi Surface of Alpha-Uranium at Ambient Pressure

We have performed de Haas-van Alphen measurements of the Fermi surface of alpha-uranium single crystals at ambient pressure within the alpha-3 charge density wave (CDW) state from 0.020 K - 10 K and magnetic fields to 35 T using torque magnetometry. The angular dependence of the resulting frequencies is described. Effective masses were measured and the Dingle temperature was determined to be 0.74 K +/- 0.04 K. The observation of quantum oscillations within the alpha-3 CDW state gives new insight into the effect of the charge density waves on the Fermi surface. In addition we observed no signature of superconductivity in either transport or magnetization down to 0.020 K indicating the possibility of a pressure-induced quantum critical point that separates the superconducting dome from the normal CDW phase.Comment: 11 pages, 4 figures, 3 table

Comparing migration in Britain and Australia: Harmonisation through use of age-time plans

Differences in the way migration is measured impede cross-national comparisons of internal migration. In this paper we utilise age-time diagrams to elucidate these problems for Australia and the United Kingdom and present solutions which generate time series of interregional migration for the two countries, harmonised with respect to age-time plans. We achieve this through estimation of the numbers of migration transitions (Australia) or migration events (Britain) for common age-period-cohort (APC) spaces. We derive appropriate population stocks for computation of transition probabilities or occurrence-exposure rates. In the final section of the paper we present a series of migration-intensity calculations based on varying combinations of period-cohort, period-age, and age-period-cohort perspectives, to demonstrate the significance of the variations, and the errors that can arise without harmonisation

Scenario Discovery with Multiple Criteria: An Evaluation of the Robust Decision‐Making Framework for Climate Change Adaptation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135989/1/risa12582_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135989/2/risa12582.pd

Changing the spatial location of electricity generation to increase water availability in areas with drought: a feasibility study and quantification of air quality impacts in Texas

The feasibility, cost, and air quality impacts of using electrical grids to shift water use from drought-stricken regions to areas with more water availability were examined. Power plant cooling represents a large portion of freshwater withdrawals in the United States, and shifting where electricity generation occurs can allow the grid to act as a virtual water pipeline, increasing water availability in regions with drought by reducing water consumption and withdrawals for power generation. During a 2006 drought, shifting electricity generation out of the most impacted areas of South Texas (~10% of base case generation) to other parts of the grid would have been feasible using transmission and power generation available at the time, and some areas would experience changes in air quality. Although expensive, drought-based electricity dispatch is a potential parallel strategy that can be faster to implement than other infrastructure changes, such as air cooling or water pipelines.National Science Foundation (U.S.). Office of Emerging Frontiers in Research and Innovation (Grant 0835414)United States. Dept. of Energ

MicroPulse DIAL (MPD) – a diode-laser-based lidar architecture for quantitative atmospheric profiling

Continuous water vapor and temperature profiles are critically needed for improved understanding of the lower atmosphere and potential advances in weather forecasting skill. Ground-based, national-scale profiling networks are part of a suite of instruments to provide such observations; however, the technological method must be cost-effective and quantitative. We have been developing an active remote sensing technology based on a diode-laser-based lidar technology to address this observational need. Narrowband, high-spectral-fidelity diode lasers enable accurate and calibration-free measurements requiring a minimal set of assumptions based on direct absorption (Beer–Lambert law) and a ratio of two signals. These well-proven quantitative methods are known as differential absorption lidar (DIAL) and high-spectral-resolution lidar (HSRL). This diode-laser-based architecture, characterized by less powerful laser transmitters than those historically used for atmospheric studies, can be made eye-safe and robust. Nevertheless, it also requires solar background suppression techniques such as narrow-field-of-view receivers with an ultra-narrow bandpass to observe individual photons backscattered from the atmosphere. We discuss this diode-laser-based lidar architecture's latest generation and analyze how it addresses a national-scale profiling network's need to provide continuous thermodynamic observations. The work presented focuses on general architecture changes that pertain to both the water vapor and the temperature profiling capabilities of the MicroPulse DIAL (MPD). However, the specific subcomponent testing and instrument validation presented are for the water vapor measurements only. A fiber-coupled seed laser transmitter optimization is performed and shown to meet all of the requirements for the DIAL technique. Further improvements – such as a fiber-coupled near-range receiver, the ability to perform quality control via automatic receiver scanning, advanced multi-channel scalar capabilities, and advanced processing techniques – are discussed. These new developments increase narrowband DIAL technology readiness and are shown to allow higher-quality water vapor measurements closer to the surface via preliminary intercomparisons within the MPD network itself and with radiosondes.</p

Irreducible triangulations of surfaces with boundary

A triangulation of a surface is irreducible if no edge can be contracted to produce a triangulation of the same surface. In this paper, we investigate irreducible triangulations of surfaces with boundary. We prove that the number of vertices of an irreducible triangulation of a (possibly non-orientable) surface of genus g>=0 with b>=0 boundaries is O(g+b). So far, the result was known only for surfaces without boundary (b=0). While our technique yields a worse constant in the O(.) notation, the present proof is elementary, and simpler than the previous ones in the case of surfaces without boundary

The complete 1/N expansion of colored tensor models in arbitrary dimension

In this paper we generalize the results of [1,2] and derive the full 1/N expansion of colored tensor models in arbitrary dimensions. We detail the expansion for the independent identically distributed model and the topological Boulatov Ooguri model