1,086 research outputs found

    Efficient loading of a He* magneto-optic trap using a liquid He cooled source

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    We report loading large numbers (up to 3×10âč) of metastable triplet helium atoms into a magneto-optical trap using an atomic beam derived from a liquid He (LHe) cooled dc discharge source. Moreover, we compare the effect of liquidN₂ cooling to LHe cooling the source and demonstrate that LHe cooling offers a significant increase in performance

    A method of teaching clinical problem-solving skills to primary health care student nurses

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    The article provides a description of a method of teaching a clinical problem-solving process to primary health care nurses/clinical nurse practitioners (PHC nurses). The process was developed in the Soweto PHC Nurse Training Unit over the past 30 years as a result of the changing availability and role of nurse and doctor teaching staff. Students doing the diploma for nurse clinicians (Diploma in Clinical Nursing Science, Health Assessment, Treatment and Care) are guided in the use of mind maps, assisted by constant clinical practice and group discussions to develop their clinical problem-solving process. This method has assisted in clinical trainingKeywords: clinical problem solving process; nurse clinicians; PHC nurse training; mind maps; self teachin

    Developing Interventions for Children's Exercise (DICE): a pilot evaluation of school-based exercise interventions for primary school children aged 7 to 8 years.

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    BACKGROUND: Developing Interventions for Children's Exercise (DICE) is an initiative aimed at determining effective school-based exercise programs. To assess feasibility, we conducted a pilot study of exercise sessions which varied in duration and frequency. METHODS: Exercise interventions were delivered to Year 3 pupils (age 7-8 years; n = 73) in primary schools within Yorkshire, UK. Evaluations were conducted using focus group sessions, questionnaires and observations. RESULTS: The study revealed positive aspects of all interventions, including favorable effects on children's concentration during lessons and identified the value of incorporation of the DICE concept into curriculum lessons. Children appeared enthused and reported well-being and enjoyment. Areas requiring attention were the need for appropriate timetabling of sessions and ensuring the availability of space. CONCLUSION: The concept and sessions were well-accepted by teachers who confirmed their full support of any future implementation There appears to be potential for the encouragement and empowerment of teachers to support physical activity and healthy school environments, and to take an interest in the health of their pupils. Ultimately, these findings should assist in the design of successful exercise interventions in the school setting

    Shallow angle water entry of ballistic projectiles

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    The water-entry of ballistic projectiles is investigated using high-speed digital imaging to capture the subsurface cavity dynamics. Specially designed 0.22 caliber projectiles are fired into water at shallow angles to the free surface (5ÂÂș to 15ÂÂș) at Mach numbers between 0.3 and 1.0. Redesigned projectile tip geometries allowed projectiles to successfully enter the water and travel large distances underwater, due to the subsurface vapor-cavity that forms after impact, dramatically decreasing drag on the projectile. Projectile dynamics, critical entry angle and cavity formation are discussed for various bullet geometries, and results show that successful water-entry is a function of tip shape and length-to-diameter ratio. The data conclusively show that bullets with lower length-to-diameter ratios tumble inside the vapor cavity, while higher length-to-diameter ratios can lean against the cavity walls inducing a planing force pushing them back inside the cavity and mitigating the tumbling behavior. Experimental cavity observations of vapor-cavity formation is compared to a modified version of Logvinovich's [1] theoretical model, which includes an updated formulation of the model and an angle of attack correction. Despite the unsteady nature of this problem, this improved steady state model fits well with experimental data and serves as an accurate design tool for naval engineers.http://deepblue.lib.umich.edu/bitstream/2027.42/84284/1/CAV2009-final100.pd

    Mentalising remotely: The AFNCCF’s adaptations to the coronavirus crisis

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    An overview of the work the approach taken by the Anna Freud National Centre for Children and Families in the rapid transition to remote working in response to the coronavirus lockdown. We outline some of the challenges of remote working and how we are seeking to mitigate them, informed by the over‐riding principle that individual relationships and the experiences of the child, young person and family must remain the central concern. The importance of maintaining a mentalising stance in remote working is discussed. We argue that a mentalising relationship which generates epistemic trust is possible in remote working, but this will require particular thought and effort on the part of the therapist. In particular, it is suggested that mentalising processes can be supported in remote working through, in the absence of the more implicit communications that are possible in face‐to‐face work, more explicit communications about mental states

    Approaching the adiabatic timescale with machine-learning

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    The control and manipulation of quantum systems without excitation is challenging, due to the complexities in fully modeling such systems accurately and the difficulties in controlling these inherently fragile systems experimentally. For example, while protocols to decompress Bose-Einstein condensates (BEC) faster than the adiabatic timescale (without excitation or loss) have been well developed theoretically, experimental implementations of these protocols have yet to reach speeds faster than the adiabatic timescale. In this work, we experimentally demonstrate an alternative approach based on a machine learning algorithm which makes progress towards this goal. The algorithm is given control of the coupled decompression and transport of a metastable helium condensate, with its performance determined after each experimental iteration by measuring the excitations of the resultant BEC. After each iteration the algorithm adjusts its internal model of the system to create an improved control output for the next iteration. Given sufficient control over the decompression, the algorithm converges to a novel solution that sets the current speed record in relation to the adiabatic timescale, beating out other experimental realizations based on theoretical approaches. This method presents a feasible approach for implementing fast state preparations or transformations in other quantum systems, without requiring a solution to a theoretical model of the system. Implications for fundamental physics and cooling are discussed.Comment: 7 pages main text, 2 pages supporting informatio
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