2,974 research outputs found

    Relativistic echo dynamics and the stability of a beam of Landau electrons

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    We extend the concepts of echo dynamics and fidelity decay to relativistic quantum mechanics, specifically in the context of Klein-Gordon and Dirac equations under external electromagnetic fields. In both cases we define similar expressions for the fidelity amplitude under perturbations of these fields, and a covariant version of the echo operator. Transformation properties under the Lorentz group are established. An alternate expression for fidelity is given in the Dirac case in terms of a 4-current. As an application we study a beam of Landau electrons perturbed by field inhomogeneities.Comment: 8 pages, no figure

    Spectral sum rules and finite volume partition function in gauge theories with real and pseudoreal fermions

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    Based on the chiral symmetry breaking pattern and the corresponding low-energy effective lagrangian, we determine the fermion mass dependence of the partition function and derive sum rules for eigenvalues of the QCD Dirac operator in finite Euclidean volume. Results are given for Nc=2N_c = 2 and for Yang-Mills theory coupled to several light adjoint Majorana fermions. They coincide with those derived earlier in the framework of random matrix theory.Comment: 22p., SUNY-NTG-94/18, TPI-MINN-94/10-

    Removal processes for tributyltin during municipal wastewater treatment

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2013 Springer.The fate and behaviour of tributyltin (TBT) at two wastewater treatment works was examined. Both sites had two inlet streams, and each utilised high rate biological filters (biofilters) on one the streams, before treatment of the combined flows on trickling filters, with one having additional tertiary processes, installed to remove ammonia and solids. The study was designed to determine if these processes enhanced the removal of TBT. Degradation of TBT was observed in one of the biofilters, possibly as a result of temperature and hydraulic loading. At the treatment works with tertiary processes, the mass flux showed the overall removal of TBT was 68 %, predominantly due to removal with solids in the primary settlement processes. However, overall removal of 95 % was observed in the conventional trickling filter works with 94 % of this due to biodegradation in the trickling filter. The two works both removed TBT, but at different treatment stages and by different processes. Differences in the form (solubility) of TBT in the influent may have attributed to this, although further understanding of factors controlling degradation would allow for a more complete assessment of the potential of biological processes to remove hazardous compounds from wastewaters.United Utilities PL

    Interactional positioning and narrative self-construction in the first session of psychodynamic-interpersonal psychotherapy

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    The purpose of this study is to identify possible session one indicators of end of treatment psychotherapy outcome using the framework of three types of interactional positioning; client’s self-positioning, client’s positioning between narrated self and different partners, and the positioning between client and therapist. Three successful cases of 8-session psychodynamic-interpersonal (PI) therapy were selected on the basis of client Beck Depression Inventory scores. One unsuccessful case was also selected against which identified patterns could be tested. The successful clients were more descriptive about their problems and demonstrated active rapport-building, while the therapist used positionings expressed by the client in order to explore the positionings developed between them during therapy. The unsuccessful case was characterized by lack of positive self-comment, minimization of agentic self-capacity, and empathy-disrupting narrative confusions. We conclude that the theory of interactional positioning has been useful in identifying patterns worth exploring as early indicators of success in PI therapy

    Statistical Properties of Random Banded Matrices with Strongly Fluctuating Diagonal Elements

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    The random banded matrices (RBM) whose diagonal elements fluctuate much stronger than the off-diagonal ones were introduced recently by Shepelyansky as a convenient model for coherent propagation of two interacting particles in a random potential. We treat the problem analytically by using the mapping onto the same supersymmetric nonlinear σ\sigma-model that appeared earlier in consideration of the standard RBM ensemble, but with renormalized parameters. A Lorentzian form of the local density of states and a two-scale spatial structure of the eigenfunctions revealed recently by Jacquod and Shepelyansky are confirmed by direct calculation of the distribution of eigenfunction components.Comment: 7 pages,RevTex, no figures Submitted to Phys.Rev.

    The PERMA well-being model and music facilitation practice: Preliminary documentation for well-being through music provision in Australian schools

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    The aim of this study was to consider how we can invest in music-making to promote well-being in school contexts. Web-based data collection was conducted where researchers identified 17 case studies that describe successful music programs in schools in Australia. The researchers aligned content from these case studies into the five categories of the PERMA well-being model: Positive emotions, Engagement, Relationships, Meaning, and Accomplishment, in order to understand how each well-being element was realised through the music programs. The results indicate that the element of the PERMA well-being model that relates to relationships was described most often. Collaboration and partnership between students, teachers, and staff in schools, and local people in the community such as parents, local entrepreneurs, and musicians were repeatedly identified as a highly significant contributing factor in the success of the music program. The school leaders? roles in providing opportunities for students to experience musical participation and related activities (engagement) and valuing these experiences (meaning) were also crucial in the facilitation of the music programs. The findings of this study indicate that tailored music and relationship-centred music programs in schools not only increase skills and abilities of the students, but also improve the psychosocial well-being of the students and the community

    Spectral Density of the QCD Dirac Operator near Zero Virtuality

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    We investigate the spectral properties of a random matrix model, which in the large NN limit, embodies the essentials of the QCD partition function at low energy. The exact spectral density and its pair correlation function are derived for an arbitrary number of flavors and zero topological charge. Their microscopic limit provide the master formulae for sum rules for the inverse powers of the eigenvalues of the QCD Dirac operator as recently discussed by Leutwyler and Smilga.Comment: 9 pages + 1 figure, SUNY-NTG-93/

    Localization in Strongly Chaotic Systems

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    We show that, in the semiclassical limit and whenever the elements of the Hamiltonian matrix are random enough, the eigenvectors of strongly chaotic time-independent systems in ordered bases can on average be exponentially localized across the energy shell and decay faster than exponentially outside the energy shell. Typically however, matrix elements are strongly correlated leading to deviations from such behavior.Comment: RevTeX, 5 pages + 3 postscript figures, submitted to Phys. Rev. Let

    Design and Culture in the Making of Happiness

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    Design responds to the needs of individuals, being happiness and wellbeing the subject of an increasing number of studies, which gave rise to a new discipline, Positive Psychology. From these new approaches and concerns related to subjective well-being comes Positive Design, whose objective is to promote the well-being of individuals and communities in connection with a culture of innovation. The cultural routes made accessible through wayfinding systems, make it possible to put Heritage in dialogue, emphasize the culture, memory and history of communities, providing citizens with meaningful experiences that will have an impact both in the short and long run, thus becoming agents for the happiness of individuals. This article discusses the concept of Positive Design based on Positive Psychology, analyzes the evolution and importance of Heritage in the Culture of peoples and communities, questioning how the Wayfinding Systems developed for cultural promotion can integrate the practice of Positive Design and how this contributes to the subjective well-being of individuals
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