Using adiabatic coupling techniques in atom-chip waveguide structures

Adiabatic techniques are well known tools in multi-level electron systems to transfer population between different states with high fidelity. Recently it has been realised that these ideas can also be used in ultra-cold atom systems to achieve coherent manipulation of the atomic centre-of-mass states. Here we present an investigation into a realistic setup using three atomic waveguides created on top of an atom chip and show that such systems hold large potential for the observation of adiabatic phenomena in experiments.Comment: 10 pages, 6 figures, accepted for publication in Physica Scripta for the CEWQO2009 proceeding

Physiotherapy after arthroscopic partial meniscectomy surgery: An assessment of costs to the National Health Service, patients and society

Objectives: The purpose of this study was to determine and inform clinicians, managers, and budget allocators of the costs incurred to the British National Health Service (NHS), patient, and society when attending clinic-based physiotherapy compared with not attending clinic-based physiotherapy after arthroscopic partial meniscectomy surgery. Methods: The valuation principle used in this study was the economic concept of opportunity cost. Costs were referred to as direct medical (NHS), direct nonmedical (patient), and indirect (societal) costs. Due to the difficulties of their measurement and valuation, intangible costs, in the form of pain and anxiety related to the effect of receiving or not receiving treatment, have not been considered in this analysis. Results: Providing clinic-based physiotherapy after knee arthroscopic partial meniscectomy surgery is more costly to the NHS and patient, but no more costly to society than when not providing it and does not result in reduced contact with the NHS. Conclusions: Clinic-based physiotherapy after knee arthroscopic partial meniscectomy surgery is costly and evidence is needed that its effectiveness is high enough to support its use

A resource survey of the coastal lands from Vlaming Head to Tantabiddi Well, West Cape Range region

The report comprise four parts; a brief review of the area\u27s climate, discussion of the geomorphology of the major landform units, an assessment of the potential erosion hazards of the surveyed landforms, and recommendations for development

Using Natural Experiments to Identify the Effects of SNAP on Child and Adult Health

The Supplemental Nutrition Assistance Program (SNAP; formerly known as food stamps) can have important impacts that extend beyond its intended aims to improve food security and nutrition, particularly for health and health care use. This project examined the impact of SNAP receipt and benefit level on the health of adults and children using two natural experiments to address selection bias: 1) state policy variation in SNAP in an instrumental variables (IV) analysis; and, 2) the temporary expansion of SNAP benefits and eligibility provided through the American Recovery and Reinvestment Act (ARRA) in a difference-in-difference (DD) approach. We used restricted data from the National Health Interview Survey (NHIS) from 2008 to 2014, restricting our sample to persons in SNAP-eligible and low-income SNAP-ineligible households. The IV analysis suggests that SNAP receipt is associated with improved health and reductions in foregone medical care due to affordability among adults and children. However, we find little evidence that ARRA’s temporary benefit increase led to any changes in health or health care use. Whereas SNAP receipt may improve health and health care use for populations close to the eligibility threshold (and thus induced to participate by some policies), the relatively small increase and reduction in SNAP benefits may not have been substantial enough to change health outcomes

An ultra-bright atom laser

We present a novel, ultra-bright atom-laser and ultra-cold thermal atom beam. Using rf-radiation we strongly couple the magnetic hyperfine levels of 87Rb atoms in a magnetically trapped Bose-Einstein condensate. At low rf-frequencies gravity opens a small hole in the trapping potenital and a well collimated, extremely bright atom laser emerges from just below the condensate. As opposed to traditional atom lasers based on weak coupling, this technique allows us to outcouple atoms at an arbitrarily large rate. We demonstrate an increase in flux per atom in the BEC by a factor of sixteen compared to the brightest quasi-continuous atom laser. Furthermore, we produce by two orders of magnitude the coldest thermal atom beam to date (200 nK).Comment: 20 pages, 9 figures, supplementary material online at http://www.bec.g

A DEM study of silo discharge of a cohesive solid

Bulk handling of powders and granular solids is common in many industries and often gives rise to handling difficulties especially when the material exhibits complex cohesive behaviour. For example, high storage stresses in a silo can lead to high cohesive strength of the stored solid, which may in turn cause blockages such as ratholing or arching near the outlet during discharge. This paper presents a Discrete Element Method study of discharge of a granular solid with varying levels of cohesion from a flat-bottomed silo. The DEM simulations were conducted using the commercial EDEM code with a recently developed DEM contact model for cohesive solids implemented through an API. The contact model is based on an elasto-plastic contact with adhesion and uses hysteretic non-linear loading and unloading paths to model the elastic-plastic contact deformation. The adhesion parameter is a function of the maximum contact overlap. The model has been shown to be able to predict the stress history dependent behaviour depicted by a flow function of the material. The effects of cohesion on the discharge rate and flow pattern in the silo are investigated. The predicted discharge rates are compared for the varying levels of cohesion and the effect of adhesion is evaluated. The ability of the contact model to qualitatively predict the phenomena that are present in the discharge of a silo has been shown with the salient feature of mixed flow from a flat bottomed hopper identified in the simulation