Modeling of Trapped Fields by Stacked (RE)BCO Tape Using Angular Transversal Field Dependence

Stacks of superconducting (RE)BCO tape are gaining popularity as a potential alternative for superconducting bulks for trapped field applications. This is partly due to versatility and uniformity of the starting material, allowing for more deterministic prediction of field profile and magnitude. However, most FEM models of trapped field magnets do not incorporate parameters such as critical current and n-value dependence on the angle of applied magnetic field, leading to only qualitative modeling results. More quantitative results can be obtained from incorporating more data for superconductivity and thermal properties of the material. Such models can be used as a starting point for most geometries and both trapped field and current transport modeling problems. An FEM model of a stack of tapes was constructed using the H formulation, incorporating goniometric critical current and n-value measurements. The modeling results were compared to field cooling experiments for stacks of different heights. The experiment and modeling show good agreement.This work was supported in part by the Engineering and Physical Sciences Research Council, U.K., and in part by SKF S2M, France

Magnetic levitation using a stack of high temperature superconducting tape annuli

Stacks of large width superconducting tape can carry persistent currents over similar length scales to bulk superconductors, therefore giving them potential for trapped field magnets and magnetic levitation. 46 mm wide high temperature superconducting tape has previously been cut into square annuli to create a 3.5 T persistent mode magnet. The same tape pieces were used here to form a composite bulk hollow cylinder with an inner bore of 26 mm. Magnetic levitation was achieved by field cooling with a pair of rare-earth magnets. This paper reports the axial levitation force properties of the stack of annuli, showing that the same axial forces expected for a uniform bulk cylinder of infinite $\textit{J c}$ can be generated at 20 K. Levitation forces up to 550 N were measured between the rare-earth magnets and stack. Finite element modelling in COMSOL Multiphysics using the H-formulation was also performed including a full critical state model for induced currents, with temperature and field dependent properties as well as the influence of the ferromagnetic substrate which enhances the force. Spark erosion was used for the first time to machine the stack of tapes proving that large stacks can be easily machined to high geometric tolerance. The stack geometry tested is a possible candidate for a rotary superconducting bearing.The authors would like to acknowledge the financial support of SKF S2M, the magnetic bearing division of SKF, the Isaac Newton Trust, Cambridge and EPSRC

Variability of serum markers of erythropoiesis during 6 days of racing in highly trained cyclists

The athlete biological passport for the fight against doping is currently based on longitudinal monitoring for abnormal changes in cellular blood parameters. Serum parameters related to altered erythropoiesis could be considered for inclusion in the passport. The aim of this study was to quantify the changes in such parameters in athletes during a period of intense exercise. 12 highly trained cyclists tapered for 3 days before 6 days of simulated intense stage racing. Morning and afternoon blood samples were taken on most days and analysed for total protein, albumin, soluble transferrin receptor and ferritin concentrations. Plasma volume was determined via total haemoglobin mass measured by carbon-monoxide rebreathing. Percent changes in means from baseline and percent standard errors of measurement (analytical error plus intra-athlete variation) on each measurement occasion were estimated with mixed linear modelling of log-transformed measures. Means of all variables changed substantially in the days following the onset of racing, ranging from −13% (haemoglobin concentration) to +27% (ferritin). After the second day, errors of measurement were generally twice those at baseline. Plasma variables were affected by heavy exercise, either because of changes in plasma volume (total protein, albumin, haemoglobin), acute phase/inflammatory reactions (ferritin) or both (soluble transferrin receptor). These effects need to be taken into consideration when integrating a plasma parameter into the biological passport model for athletes

Toward Uniform Trapped Field Magnets Using a Stack of Roebel Cable Offcuts

Stacks of high temperature superconducting tape can be magnetized to produce a variety of different trapped field profiles in addition to the most common conical or pyramidal profiles. Stacks of tape using discarded Roebel cable offcuts were created to investigate various stacking arrangements with the aim of creating a stack that can be magnetized to produce a uniform trapped field for potential applications such as NMR. A new angled stacking arrangement proved to produce the flattest, most uniform field of all the overlapping stacking arrangements and has the potential to be scaled up. FEM modeling in COMSOL was also performed to complement the measurements and explain the limitations and advantages of the stacking arrangements tested.This work was supported in part by the Engineering and Physical Sciences Research Council, U.K., and in part by SKF S2M, France.This is the author accepted manuscript. The final version is available from IEEE via http://dx.doi.org/10.1109/TASC.2016.251899

Noninterventional statistical comparison of BTS and CHEST guidelines for size and severity in primary pneumothorax.

Hilar rather than apical interpleural distance more accurately predicts need for intercostal chest drain insertion http://ow.ly/JvKFYThe study was funded by the East Anglian Thoracic Society. M.Z. Nikolić is a Wellcome Trust PhD Programme for Clinicians Fellow at the University of Cambridge. S.J. Marciniak is a Medical Research Council Senior Clinical Fellow. J. Wason is funded by the Cambridge Biomedical Research Centre. Funding information for this article has been deposited with FundRef.This is the final version of the article. It first appeared from the European Respiratory Society via http://dx.doi.org/10.1183/09031936.0011861

Corpus Callosum Morphology in Capuchin Monkeys Is Influenced by Sex and Handedness

Sex differences have been reported in both overall corpus callosum area and its regional subdivisions in humans. Some have suggested this reflects a unique adaptation in humans, as similar sex differences in corpus callosum morphology have not been reported in any other species of primate examined to date. Furthermore, an association between various measurements of corpus callosum morphology and handedness has been found in humans and chimpanzees. In the current study, we report measurements of corpus callosum cross-sectional area from midsagittal MR images collected in vivo from 14 adult capuchin monkeys, 9 of which were also characterized for hand preference on a coordinated bimanual task. Adult females were found to have a significantly larger corpus callosum: brain volume ratio, rostral body, posterior midbody, isthmus, and splenium than adult males. Left-handed individuals had a larger relative overall corpus callosum area than did right-handed individuals. Additionally, a significant sex and handedness interaction was found for anterior midbody, with right-handed males having a significantly smaller area than right-handed females. These results suggest that sex and handedness influences on corpus callosum morphology are not restricted to Homo sapiens

The validity of two widely used commercial and research-grade activity monitors, during resting, household and activity behaviours

Wearable devices are increasingly prevalent in research environments for the estimation of energy expenditure (EE) and heart rate (HR). The aim of this study was to validate the HR and EE estimates of the Fitbit charge 2 (FC2), and the EE estimates of the Sensewear armband mini (SWA). We recruited 59 healthy adults to participate in walking, running, cycling, sedentary and household tasks. Estimates of HR from the FC2 were compared to a HR chest strap (Polar) and EE to a stationary metabolic cart (Vyntus CPX). The SWA overestimated overall EE by 0.03 kcal/min−1 and was statistically equivalent to the criterion measure, with a mean absolute percentage error (MAPE) of 29%. In contrast, the FC2 was not equivalent overall (MAPE = 44%). In household tasks, MAPE values of 93% and 83% were observed for the FC2 and SWA, respectively. The FC2 HR estimates were equivalent to the criterion measure overall. The SWA is more accurate than the commercial-grade FC2. Neither device is consistently accurate across the range of activities used in this study. The HR data obtained from the FC2 is more accurate than its EE estimates and future research may focus more on this variable

Trail laying during tandem-running recruitment in the ant Temnothorax albipennis

Tandem running is a recruitment strategy whereby one ant leads a single naïve nest mate to a resource. While tandem running progresses towards the goal, the leader ant and the follower ant maintain contact mainly by tactile signals. In this paper, we investigated whether they also deposit chemical signals on the ground during tandem running. We filmed tandem-running ants and analysed the position of the gasters of leaders and followers. Our results show that leader ants are more likely to press their gasters down to the substrate compared to follower ants, single ants and transporter ants. Forward tandem-run leaders (those moving towards a new nest site) performed such trail-marking procedures three times more often than reverse tandem leaders (those moving towards an old nest site). That leader ants marked the trails more often during forward tandem runs may suggest that it is more important to maintain the bond with the follower ant on forward tandem runs than on reverse tandem runs. Marked trails on the ground may serve as a safety line that improves both the efficiency of tandem runs and their completion rates. © 2014 Springer-Verlag Berlin Heidelberg

The Surgical Infection Society revised guidelines on the management of intra-abdominal infection

Background: Previous evidence-based guidelines on the management of intra-abdominal infection (IAI) were published by the Surgical Infection Society (SIS) in 1992, 2002, and 2010. At the time the most recent guideline was released, the plan was to update the guideline every five years to ensure the timeliness and appropriateness of the recommendations. Methods: Based on the previous guidelines, the task force outlined a number of topics related to the treatment of patients with IAI and then developed key questions on these various topics. All questions were approached using general and specific literature searches, focusing on articles and other information published since 2008. These publications and additional materials published before 2008 were reviewed by the task force as a whole or by individual subgroups as to relevance to individual questions. Recommendations were developed by a process of iterative consensus, with all task force members voting to accept or reject each recommendation. Grading was based on the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) system; the quality of the evidence was graded as high, moderate, or weak, and the strength of the recommendation was graded as strong or weak. Review of the document was performed by members of the SIS who were not on the task force. After responses were made to all critiques, the document was approved as an official guideline of the SIS by the Executive Council. Results: This guideline summarizes the current recommendations developed by the task force on the treatment of patients who have IAI. Evidence-based recommendations have been made regarding risk assessment in individual patients; source control; the timing, selection, and duration of antimicrobial therapy; and suggested approaches to patients who fail initial therapy. Additional recommendations related to the treatment of pediatric patients with IAI have been included. Summary: The current recommendations of the SIS regarding the treatment of patients with IAI are provided in this guideline