144 research outputs found

    Equipment Level of Technical Education/Culture Classrooms in Accordance With Pedagogical Standards for Primary Education and Norms of School Space in The Federation of Bosnia and Herzegovina

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    Full standardization that is adequate to the goal and function of teaching technical contents in primary schools still hasnrsquot been done in the educational system of Bosnia amp Herzegovina. An equipped classroom in accordance with the pedagogical standards for primary education and norms of school space in schools of the Federation of Bosnia and Herzegovina, and which is the case in all of Bosnia and Herzegovina, doesnrsquot come even close to the accepted standards and norms. Classrooms, in which a systematic, non-experimental observation of the degree of readiness to hold a class in has been held, have shownnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbsp a disturbing lack of tools and equipment needed to holdnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbspnbsp a successful lecture. For a more detailed and all-encompassing work in the field, several changes have to be made: material-technical basis of work (equip schools with teaching aids, materials, adequate tools and machines for specialized work), teaching plans and programs (reduce the comprehensive curricula, and adjust it to the age of the pupils), didactic-methodic basis of work, and the stands in most important factors in educational work (students and teachers). Curriculum and syllabi for this subject need adjusting with the psycho-physical age of the learner and in that way allow them to follow trends in technology, and in return theyrsquod be more included in the process of realization of the subject. It is necessary to modernize the class, focus the teaching onto the learner, and secure constant learning opportunities to the teachers through seminars and education on various techniques and technologies that can be applied in teaching. Keeping in touch with the times we live in, following the latest technological advancements and applying them in the teaching process is the path that education has to follow

    Excitonic Superfluid to pseudo-spin density wave transition in bilayer quantum Hall systems

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    We construct a quantum Ginsburg-Landau theory to study the quantum phase transition from the excitonic superfluid (ESF) to a possible pseudo-spin density wave (PSDW) at some intermediate distances driven by the magneto-roton minimum collapsing at a finite wavevector. We analyze the properties of the PSDW and explicitly show that a square lattice is the favorite lattice. We suggest that correlated hopping of vacancies in the active and passive layers in the PSDW state leads to very large and temperature dependent drag consistent with the experimental data. Comparisons with previous microscopic numerical calculations are made. Further experimental implications are given.Comment: 4+ pages, 2 figures. Final version to appear in Phys. Rev. Let

    Reactive Dye Degradation by AOPs; Development of a Kinetic Model for UV/H2O2 Process

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    An application of UV/H2O2 process for the treatment of model wastewater containing organic reactive azo dye C.I. Reactive Blue 137 (RB137) was studied. The efficiency of applied process for decolorization and mineralization of RB137 model solution is discussed. The influence of operating process parameters, initial pH and initial concentration of H2O2, as well as initial dye mass concentration on process effectiveness was investigated. Both direct UV photolysis and OH radical attack were assumed as RB137 degradation mechanisms and a detailed kinetic model for dye degradation by UV/H2O2 process was proposed. The predicted system behavior was compared with experimentally obtained results of decolorization and mineralization of RB137 wastewater. A sensitivity analysis for the evaluation of importance of each reaction used in the model development was also included

    Reactive Dye Degradation by AOPs; Development of a Kinetic Model for UV/H2O2 Process

    Get PDF
    An application of UV/H2O2 process for the treatment of model wastewater containing organic reactive azo dye C.I. Reactive Blue 137 (RB137) was studied. The efficiency of applied process for decolorization and mineralization of RB137 model solution is discussed. The influence of operating process parameters, initial pH and initial concentration of H2O2, as well as initial dye mass concentration on process effectiveness was investigated. Both direct UV photolysis and OH radical attack were assumed as RB137 degradation mechanisms and a detailed kinetic model for dye degradation by UV/H2O2 process was proposed. The predicted system behavior was compared with experimentally obtained results of decolorization and mineralization of RB137 wastewater. A sensitivity analysis for the evaluation of importance of each reaction used in the model development was also included

    Probing the geometry of the Laughlin state

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    It has recently been pointed out that phases of matter with intrinsic topological order, like the fractional quantum Hall states, have an extra dynamical degree of freedom that corresponds to quantum geometry. Here we perform extensive numerical studies of the geometric degree of freedom for the simplest example of fractional quantum Hall states—the filling Îœ=1/3\nu =1/3 Laughlin state. We perturb the system by a smooth, spatially dependent metric deformation and measure the response of the Hall fluid, finding it to be proportional to the Gaussian curvature of the metric. Further, we generalize the concept of coherent states to formulate the bulk off-diagonal long range order for the Laughlin state, and compute the deformations of the metric in the vicinity of the edge of the system. We introduce a \u27pair amplitude\u27 operator and show that it can be used to numerically determine the intrinsic metric of the Laughlin state. These various probes are applied to several experimentally relevant settings that can expose the quantum geometry of the Laughlin state, in particular to systems with mass anisotropy and in the presence of an electric field gradient

    Quantum Hall Effects in Graphene-Based Two-Dimensional Electron Systems

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    In this article we review the quantum Hall physics of graphene based two-dimensional electron systems, with a special focus on recent experimental and theoretical developments. We explain why graphene and bilayer graphene can be viewed respectively as J=1 and J=2 chiral two-dimensional electron gases (C2DEGs), and why this property frames their quantum Hall physics. The current status of experimental and theoretical work on the role of electron-electron interactions is reviewed at length with an emphasis on unresolved issues in the field, including assessing the role of disorder in current experimental results. Special attention is given to the interesting low magnetic field limit and to the relationship between quantum Hall effects and the spontaneous anomalous Hall effects that might occur in bilayer graphene systems in the absence of a magnetic field

    Whole-genome sequence of the first sequence type 27 Brucella ceti strain isolated from European waters

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    ABSTRACT Brucella spp. that cause marine brucellosis are becoming more important, as the disease appears to be more widespread than originally thought. Here, we report a whole and annotated genome sequence of Brucella ceti CRO350, a sequence type 27 strain isolated from a bottlenose dolphin carcass found in the Croatian part of the northern Adriatic Sea. </jats:p

    Benchmarking and Validation of Cascading Failure Analysis Tools

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    Cascading failure in electric power systems is a complicated problem for which a variety of models, software tools, and analytical tools have been proposed but are difficult to verify. Benchmarking and validation are necessary to understand how closely a particular modeling method corresponds to reality, what engineering conclusions may be drawn from a particular tool, and what improvements need to be made to the tool in order to reach valid conclusions. The community needs to develop the test cases tailored to cascading that are central to practical benchmarking and validation. In this paper, the IEEE PES working group on cascading failure reviews and synthesizes how benchmarking and validation can be done for cascading failure analysis, summarizes and reviews the cascading test cases that are available to the international community, and makes recommendations for improving the state of the art

    Emergent SU(2) dynamics and perfect quantum many-body scars

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    Motivated by recent experimental observations of coherent many-body revivals in a constrained Rydberg atom chain, we construct a weak quasi-local deformation of the Rydberg blockade Hamiltonian, which makes the revivals virtually perfect. Our analysis suggests the existence of an underlying non-integrable Hamiltonian which supports an emergent SU(2)-spin dynamics within a small subspace of the many-body Hilbert space. We show that such perfect dynamics necessitates the existence of atypical, nonergodic energy eigenstates - quantum many-body scars. Furthermore, using these insights, we construct a toy model that hosts exact quantum many-body scars, providing an intuitive explanation of their origin. Our results offer specific routes to enhancing coherent many-body revivals, and provide a step towards establishing the stability of quantum many-body scars in the thermodynamic limit

    Spin and valley quantum Hall ferromagnetism in graphene

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    In a graphene Landau level (LL), strong Coulomb interactions and the fourfold spin/valley degeneracy lead to an approximate SU(4) isospin symmetry. At partial filling, exchange interactions can spontaneously break this symmetry, manifesting as additional integer quantum Hall plateaus outside the normal sequence. Here we report the observation of a large number of these quantum Hall isospin ferromagnetic (QHIFM) states, which we classify according to their real spin structure using temperature-dependent tilted field magnetotransport. The large measured activation gaps confirm the Coulomb origin of the broken symmetry states, but the order is strongly dependent on LL index. In the high energy LLs, the Zeeman effect is the dominant aligning field, leading to real spin ferromagnets with Skyrmionic excitations at half filling, whereas in the `relativistic' zero energy LL, lattice scale anisotropies drive the system to a spin unpolarized state, likely a charge- or spin-density wave.Comment: Supplementary information available at http://pico.phys.columbia.ed
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