Non-uniform vortex lattices in inhomogeneous rotating Bose-Einstein condensates

We derive a general framework, in terms of elastic theory, for describing the distortion of the vortex lattice in a rotating Bose-Einstein condensate at arbitrary rotation speed and determining the dependence of the distortion on the density inhomogeneity of the system. In the rapidly rotating limit, we derive the energetics in terms of Landau levels, including excitation to higher levels; the distortion depends on the excitation of higher levels as well as on the density gradient. As we show, the dominant effect of higher Landau levels in a distorted lattice in equilibrium is simply to renormalize the frequency entering the lowest Landau level condensate wave function -- from the transverse trap frequency, $\omega$, to the rotational frequency, $\Omega$, of the system. Finally, we show how the equilibrium lattice distortion emerges from elastohydrodynamic theory for inhomogeneous systems.Comment: 6 pages, no figure

Lithium-sulfur batteries: lightweight technology for multiple sectors

Lithium-sulfur technology has the potential to offer cheaper, lighter-weight batteries that also offer safety advantages. After initially finding use in niche markets such as satellites, drones and military vehicles, the technology has the potential to transform aviation in the long-term. Electric aircraft offering short-range flights or vertical take-off and landing (including personalised aviation and flying taxis in cities) are distinct possibilities by 2050. The UK, which is already home to established lithium-sulfur battery manufacturers and to leading academics in the field, has a great opportunity to be the global leader in this ground-breaking technology

An eighth-century inscribed cross-slab in Dull, Perthshire

The discovery of a cross-inscribed slab with an inscription is described. Because of its importance it was decided to invite specialist comment on this piece of sculpture and to publish it in advance of the full report on the excavations. The form of the monument, its inscription and archaeological context are considered. The text appears to consist of a Gaelic personal name. The script is a form of geometrical lettering which can be dated to the opening quarter of the eighth century. The form of the cross has Columban associations which sit well with place-name and other evidence which points to Dull having been a monastery founded from Iona by c. AD 700

Structure of vortices in rotating Bose-Einstein condensates

We calculate the structure of individual vortices in rotating Bose-Einstein condensates in a transverse harmonic trap. Making a Wigner-Seitz approximation for the unit cell of the vortex lattice, we derive the Gross-Pitaevskii equation for the condensate wave function in each cell of the lattice, including effects of varying coarse grained density. We calculate the Abrikosov parameter, the fractional core area, and the energy of individual cells.Comment: 10 pages, 9 figures, published versio

CREST Cost of Renewable Energy Spreadsheet Tool: A Model for Developing Cost-Based Incentives in the United States; User Manual Version 4, August 2009 - March 2011 (Updated July 2013)

The objective of this document is to help model users understand how to use the CREST model to support renewable energy incentives, FITs, and other renewable energy rate-setting processes. This user manual will walk the reader through the spreadsheet tool, including its layout and conventions, offering context on how and why it was created. This user manual will also provide instructions on how to populate the model with inputs that are appropriate for a specific jurisdiction's policymaking objectives and context. Finally, the user manual will describe the results and outline how these results may inform decisions about long-term renewable energy support programs

The calibrated population resistance tool: standardized genotypic estimation of transmitted HIV-1 drug resistance

Summary: The calibrated population resistance (CPR) tool is a web-accessible program for performing standardized genotypic estimation of transmitted HIV-1 drug resistance. The program is linked to the Stanford HIV drug resistance database and can additionally perform viral genotyping and algorithmic estimation of resistance to specific antiretroviral drugs

Skeletal responses to an all-female unassisted Antarctic traverse

Purpose: To investigate the skeletal effects of the first all-female trans-Antarctic traverse. Methods: Six women (mean ± SD, age 32 ±3 years, height 1.72 ± 0.07m, body mass 72.8 ± 4.0kg) hauled 80kg sledges over 1700km in 61days from coast-to-coast across the Antarctic. Whole-body areal bone mineral density (aBMD) (dual-energy X-ray absorptiometry) and tibial volumetric BMD (vBMD), geometry, microarchitecture and estimated mechanical properties (high-resolution peripheral quantitative computed tomography) were assessed 39 days before (pre-expedition) and 15 days after the expedition (post-expedition). Serum and plasma markers of bone turnover were assessed pre-expedition, and 4 and 15 days after the expedition. Results: There were reductions in trunk (−2.6%), ribs (−5.0%) and spine (−3.4%) a BMD from pre-to post-expedition (all P≤0.046); arms, legs, pelvis and total body a BMD were not different (all P≥0.075). Tibial v BMD, geometry, microarchitecture and estimated mechanical properties at the metaphysis (4% site) and diaphysis (30% site) were not different between pre-and post-expedition (all P≥0.082). Bone-specific alkaline phosphatase was higher 15days post-than 4 days post-expedition (1.7 μg∙l⁠−1, P=0.028). Total 25(OH) D decreased from pre-to 4 dayspost expedition (−36nmol∙l⁠−1,P=0.008).Sclerostin,procollagen1N-terminal propeptide, C-telopeptide cross-links of type 1 collagen and adjusted calcium were unchanged (allP≥0.154). Conclusion: Adecline in a BMD of the axial skeleton maybe due to indirect and direct effects of prolonged energy deficit. We propose that weight-bearing exercise was protective against the effects of energy deficit on tibial v BMD, geometry, microarchitecture and strength

Core handling and processing for the WAIS Divide ice-core project

On 1 December 2011 the West Antarctic Ice Sheet (WAIS) Divide ice-core project reached its final depth of 3405 m. The WAIS Divide ice core is not only the longest US ice core to date, but is also the highest-quality deep ice core, including ice from the brittle ice zone, that the US has ever recovered. The methods used at WAIS Divide to handle and log the drilled ice, the procedures used to safely retrograde the ice back to the US National Ice Core Laboratory (NICL) and the methods used to process and sample the ice at the NICL are described and discussed

Core handling and processing for the WAIS Divide ice-core project

On 1 December 2011 the West Antarctic Ice Sheet (WAIS) Divide ice-core project reached its final depth of 3405 m. The WAIS Divide ice core is not only the longest US ice core to date, but is also the highest-quality deep ice core, including ice from the brittle ice zone, that the US has ever recovered. The methods used at WAIS Divide to handle and log the drilled ice, the procedures used to safely retrograde the ice back to the US National Ice Core Laboratory (NICL) and the methods used to process and sample the ice at the NICL are described and discussed