225 research outputs found

    Modern Developments in Engineering of Oxygen Steelmaking Shops for Bottom and Combined Blowing

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    The bottom blown basic oxygen steelmaking process was introduced and tested on low phosphorus hot metal in North America during 1971, The OBM/Q-BOP process proved to be an improvement over the top blown basic oxygen process in many aspects - capital costs, operating_costs, and process capabilities. Capital costs could be saved mainly because of much reduced Space requirements and deletion (particularly in the case of open hearth con-version) of extensive overhead material storage and han-dling systems due to the absence of lop lances and beca-use pneumatic material handling and bottom injection per-mitted replacement of gravity fed top additions. Operat-ing costs were reduced by a combination of high produc-tivity due to the capability of greater specific oxygen blowing rates and better product yields, both from charged-and additive materials

    Time Resolved Experiments at the Frankfurt 14 GHz ECR Ion Source

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    To investigate the basic production processes of highly charged ions and combined phenomena of an ECRIS plasma (e. g. influence of secondary electrons and plasma instabilities) time resolved experiments have been carried out at the Frankfurt 14 GHz ECRIS [1] (see also the contributions to this workshop by O. Hohn et al. and V. Mironov et al.). We report time resolved measurements of the extracted ion currents by pulsing the biased disk voltage [2]. The measurements have shown that the extracted ion currents respond too fast to explain the "biased disk effect" (i. e. the intensity increase of highly charged ions) by enhanced ion breeding. Furthermore the influence of the pulsed biased disk on plasma instabilities has been investigated. It has also been shown that this method can be used to extract pulsed ion beams from an ECRIS

    Making mentoring work: The need for rewiring epistemology

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    To help produce expert coaches at both participation and performance levels, a number of governing bodies have established coach mentoring systems. In light of the limited literature on coach mentoring, as well as the risks of superficial treatment by coach education systems, this paper therefore critically discusses the role of the mentor in coach development, the nature of the mentor-mentee relationship and, most specifically, how expertise in the mentee may best be developed. If mentors are to be effective in developing expert coaches then we consequently argue that a focus on personal epistemology is required. On this basis, we present a framework that conceptualizes mentee development on this level through a step by step progression, rather than unrealistic and unachievable leap toward expertise. Finally, we consider the resulting implications for practice and research with respect to one-on-one mentoring, communities of practice, and formal coach education

    Coherent Population Trapping with Controlled Interparticle Interactions

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    We investigate Coherent Population Trapping in a strongly interacting ultracold Rydberg gas. Despite the strong van der Waals interactions and interparticle correlations, we observe the persistence of a resonance with subnatural linewidth at the single-particle resonance frequency as we tune the interaction strength. This narrow resonance cannot be understood within a meanfield description of the strong Rydberg--Rydberg interactions. Instead, a many-body density matrix approach, accounting for the dynamics of interparticle correlations, is shown to reproduce the observed spectral features

    Status of the Frankfurt 14 GHz-ECRIS-(ve)RFQ Facility

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    The accelerator facility installed at the Institut fuer Kernphysik (IKF) combines a 14 GHz electron cyclotron resonance ion source (ECRIS) and a variable energy radio frequency quadrupole accelerator (ve-RFQ)[1,2]. The provided highly charged ions have an energy range between a few keV - using the beam delivered from the source - up to 200 keV/u by using the post acceleration of the ve-RFQ. The setup is designed to deliver a wide spectrum of ions in sufficiently high charged states for atomic physics and materials research. Besides this the ion source is used for studies of the production of highly charged ions with the intention to improve quality and intensity of ion beams. In addition to these activities there are some special topics which deal with the investigation of phenomena on the ECRIS plasma and the production of metal ions by laser ablation technique (see also contributions to this workshop S. Runkel et al. And V. Mironov et. al). The present status and further activities of the facility and a view of the different projects will be reported

    Symplectically Covariant Schr\"{o}dinger Equation in Phase Space

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    A classical theorem of Stone and von Neumann says that the Schr\"{o}dinger representation is, up to unitary equivalences, the only irreducible representation of the Heisenberg group on the Hilbert space of square-integrable functions on configuration space. Using the Wigner-Moyal transform we construct an irreducible representation of the Heisenberg group on a certain Hilbert space of square-integrable functions defined on phase space. This allows us to extend the usual Weyl calculus into a phase-space calculus and leads us to a quantum mechanics in phase space, equivalent to standard quantum mechanics. We also briefly discuss the extension of metaplectic operators to phase space and the probabilistic interpretation of the solutions of the phase space Schr\"{o}dinger equationComment: To appear in J Phys

    Professionalism, Golf Coaching and a Master of Science Degree: A commentary

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    As a point of reference I congratulate Simon Jenkins on tackling the issue of professionalism in coaching. As he points out coaching is not a profession, but this does not mean that coaching would not benefit from going through a professionalization process. As things stand I find that the stimulus article unpacks some critically important issues of professionalism, broadly within the context of golf coaching. However, I am not sure enough is made of understanding what professional (golf) coaching actually is nor how the development of a professional golf coach can be facilitated by a Master of Science Degree (M.Sc.). I will focus my commentary on these two issues

    Moving beyond physical education subject knowledge to develop knowledgeable teachers of the subject

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    All knowledge is socially constructed, including physical education teachers’ knowledge of their subject. It is acquired from other people either formally and deliberately (e.g. by being taught) or informally and casually (e.g. by interacting with physical education teachers or playing in a sports team). The social aspects of learning appear to be particularly strong in physical education. This has implications for the development of knowledge for teaching, with trainee teachers focusing on the development of subject, and particularly content, knowledge. Focusing on subject knowledge reinforces a traditional view of physical education as it is, not as it might be to meet the needs of young people today. It is argued that attention needs to be given not only to the knowledge, skills and competencies that trainee teachers ought to develop but also to the social aspects of their learning and development and the context in which they learn. Attention also needs to be given to how the ability to think critically can be developed so that trainee teachers can become reflective practitioners able to challenge and, where appropriate, change the teaching of the subject. Only by doing this can the particularly strong socialisation which shapes the values and beliefs of physical education teachers begin to be challenged. However, as the process of developing knowledgeable teachers is ongoing it is also necessary to look beyond teacher training to continuing professional development

    Moving beyond physical education subject knowledge to develop knowledgeable teachers of the subject

    Get PDF
    All knowledge is socially constructed, including physical education teachers’ knowledge of their subject. It is acquired from other people either formally and deliberately (e.g. by being taught) or informally and casually (e.g. by interacting with physical education teachers or playing in a sports team). The social aspects of learning appear to be particularly strong in physical education. This has implications for the development of knowledge for teaching, with trainee teachers focusing on the development of subject, and particularly content, knowledge. Focusing on subject knowledge reinforces a traditional view of physical education as it is, not as it might be to meet the needs of young people today. It is argued that attention needs to be given not only to the knowledge, skills and competencies that trainee teachers ought to develop but also to the social aspects of their learning and development and the context in which they learn. Attention also needs to be given to how the ability to think critically can be developed so that trainee teachers can become reflective practitioners able to challenge and, where appropriate, change the teaching of the subject. Only by doing this can the particularly strong socialisation which shapes the values and beliefs of physical education teachers begin to be challenged. However, as the process of developing knowledgeable teachers is ongoing it is also necessary to look beyond teacher training to continuing professional development
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