453 research outputs found

    Field aligned flows driven by neutral puffing at MAST

    Get PDF

    Exploration of Non-Resonant Divertor Features on the Compact Toroidal Hybrid

    Full text link
    Non-resonant divertors (NRDs) separate the confined plasma from the surrounding plasma facing components (PFCs). The resulting striking field line intersection pattern on these PFCs is insensitive to plasma equilibrium effects. However, a complex scrape-off layer (SOL), created by chaotic magnetic topology in the plasma edge, connects the core plasma to the PFCs through varying magnetic flux tubes. The Compact Toroidal Hybrid (CTH) serves as a test-bed to study this by scanning across its inductive current. Simulations observe a significant change of the chaotic edge structure and an effective distance between the confined plasma and the instrumented wall targets. The intersection pattern is observed to be a narrow helical band, which we claim is a resilient strike line pattern. However, signatures of finger-like structures, defined as heteroclinic tangles in chaotic domains, within the plasma edge connect the island chains to this resilient pattern. The dominant connection length field lines intersecting the targets are observed via heat flux modelling with EMC3-EIRENE. At low inductive current levels, the excursion of the field lines resembles a limited plasma wall scenario. At high currents, a private flux region is created in the area where the helical strike line pattern splits into two bands. These bands are divertor legs with distinct SOL parallel particle flow channels. The results demonstrate the NRD strike line pattern resiliency within CTH, but also show the underlying chaotic edge structure determining if the configuration is diverted or limited. This work supports future design efforts for a mechanical structure for the NRD.Comment: 26 pages, 16 figure

    Promotion of healthy nutrition in clinical practice: a cross-sectional survey of practices and barriers among physiotherapists in southeast Nigeria

    Get PDF
    AbstractBackgroundHealthy diet counselling is an important concept in health promotion. Physiotherapists are well positioned to initiate or support healthy nutrition in addition to physical activity counselling, in routine patient consultation.ObjectiveTo determine the practices about and barriers to diet counselling practices among physiotherapists in Southeast Nigeria.MethodsIn this cross-sectional survey, a total of 140 questionnaires were distributed among physiotherapists.ResultsOverall, 103 physiotherapists responded. Physiotherapists are confident and consider the incorporation of dietary counselling very important and of high priority in their daily clinical work. They, however, assessed and counselled on dietary status opportunistically in patients. Notwithstanding, physiotherapists believed that the diet counselling they give could be effective in helping patients change their unhealthy dieting practices. Patients were also amenable to physiotherapists advocating on diet issues as part of their consultation. Several barriers to incorporating diet counselling into physiotherapy practice were identified, including lack of access to a dietician/health promotion staff/counsellors, lack of proper patient education materials, lack of expertise in relation to dietary risk factors' assessment and management, and uncertainty about what dietary services to provide.ConclusionAlthough physiotherapists consider it important to incorporate diet counselling in their daily clinical practice, development and implementation of strategies to improve physiotherapists' diet counselling knowledge, competence, skills, and practice are warranted

    Demonstration of quantum Zeno effect in a superconducting phase qubit

    Full text link
    Quantum Zeno effect is a significant tool in quantum manipulating and computing. We propose its observation in superconducting phase qubit with two experimentally feasible measurement schemes. The conventional measurement method is used to achieve the proposed pulse and continuous readout of the qubit state, which are analyzed by projection assumption and Monte Carlo wave-function simulation, respectively. Our scheme gives a direct implementation of quantum Zeno effect in a superconducting phase qubit.Comment: 5 pages, 4 figure

    High-throughput synthesis of CeO<sub>2</sub> nanoparticles for transparent nanocomposites repelling Pseudomonas aeruginosa biofilms

    Get PDF
    Preventing bacteria from adhering to material surfaces is an important technical problem and a major cause of infection. One of nature’s defense strategies against bacterial colonization is based on the biohalogenation of signal substances that interfere with bacterial communication. Biohalogenation is catalyzed by haloperoxidases, a class of metal-dependent enzymes whose activity can be mimicked by ceria nanoparticles. Transparent CeO(2)/polycarbonate surfaces that prevent adhesion, proliferation, and spread of Pseudomonas aeruginosa PA14 were manufactured. Large amounts of monodisperse CeO(2) nanoparticles were synthesized in segmented flow using a high-throughput microfluidic benchtop system using water/benzyl alcohol mixtures and oleylamine as capping agent. This reduced the reaction time for nanoceria by more than one order of magnitude compared to conventional batch methods. Ceria nanoparticles prepared by segmented flow showed high catalytic activity in halogenation reactions, which makes them highly efficient functional mimics of haloperoxidase enzymes. Haloperoxidases are used in nature by macroalgae to prevent formation of biofilms via halogenation of signaling compounds that interfere with bacterial cell–cell communication (“quorum sensing”). CeO(2)/polycarbonate nanocomposites were prepared by dip-coating plasma-treated polycarbonate panels in CeO(2) dispersions. These showed a reduction in bacterial biofilm formation of up to 85% using P. aeruginosa PA14 as model organism. Besides biofilm formation, also the production of the virulence factor pyocyanin in is under control of the entire quorum sensing systems P. aeruginosa. CeO(2)/PC showed a decrease of up to 55% in pyocyanin production, whereas no effect on bacterial growth in liquid culture was observed. This indicates that CeO(2) nanoparticles affect quorum sensing and inhibit biofilm formation in a non-biocidal manner
    • …
    corecore