4,030 research outputs found

    Competing Institutional Logics And Teaching Effectiveness In Traditional And Online University Classrooms

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    Relying on an institutional logics framework, we use a case study method to investigate competing inter-institutional logics effecting U.S. postsecondary teaching effectiveness ratings in traditional and online courses at a midsize Texas public university. Prior research attributes differences to instructor and student attitudes, performative characteristics, and motivation but few studies have examined evaluation outcomes in light of competing logics that contextualize administrators, faculty, and students’ practices in the qualitatively different classroom settings. Using a multilevel latent factor model, we correlated variances in students’ assessments on key institutional criteria and compare differences in students’ teaching effectiveness ratings between the two settings. We theorized that different neoliberal dispositions emerge from competing institutional logics framing actors\u27 normative assumptions in traditional and online classrooms. The findings indicate that instructors’ significantly lower evaluations in online classes were linked to competing institutional logics affecting actors’ cognitions and practices. Noteworthy was students’ assessments were not gender biased from an institutional logics perspective in either instructional field

    Interference of Quantum Channels

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    We show how interferometry can be used to characterise certain aspects of general quantum processes, in particular, the coherence of completely positive maps. We derive a measure of coherent fidelity, maximum interference visibility and the closest unitary operator to a given physical process under this measure.Comment: 4 pages, 5 figures, REVTeX 4, typographical corrections and added acknowledgemen

    Reply to `Singularities of the mixed state phase'

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    The only difference between Bhandari's viewpoint [quant-ph/0108058] and ours [Phys. Rev. Lett. 85, 2845 (2000)] is that our phase is defined modulo 2π2\pi, whereas Bhandari argues that two phases that differ by 2πn2\pi n, nn integer, may be distinguished experimentally in a history-dependent manner.Comment: 2 page

    Energy Calculator for Solar Processing of Biomass with Application to Uganda

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    Rural areas of developing countries often have poor energy infrastructure and so rely on a very local supply. A local energy supply in rural Uganda frequently has problems such as limited accessibility, unreliability, a high expense, harmful to health and deforestation. By carbonizing waste biomass streams, available to those in rural areas of developing countries through a solar resource, it would be possible to create stable, reliable fuels with more consistent calorific values. An energy demand calculator is reported to assess the different energy demands of various thermochemical processes that can be used to create biofuel. The energy demand calculator then relates the energy required to the area of solar collector required for an integrated system. Pyrolysis was shown to require the least amount of energy to process 1 kg of biomass when compared to steam treatment and hydrothermal carbonization (HTC). This was due to the large amount of water required for steam treatment and HTC. A resource assessment of Uganda is reported, to which the energy demand calculator has been applied. Quantitative data are presented for agricultural residues, forestry residues, animal manure and aquatic weeds found within Uganda. In application to rural areas of Uganda, a linear Fresnel HTC integration shows to be the most practical fit. Integration with a low temperature steam treatment would require more solar input for less carbonization due to the energy required to vaporize liquid water

    Role resources and work-family enrichment: The role of work engagement

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    The majority of work-family research has focused on negative spillover between demands and outcomes and between the work and family domains (e.g., work-family conflict; see review by Eby, Casper, Lockwood, Bordeaux, & Brinley, 2005). The theory that guided this research was in most cases role stress theory (Greenhaus & Beutell, 1985) or the role scarcity hypothesis (Edwards & Rothbard, 2000). However, according to spillover theory, work-related activities and satisfaction also affect non-work performance, and vice versa. Recently, in line with the positive psychology movement (Seligman & Csikszentmihalyi, 2000), work-family interaction research has also included concepts of positive spillover (Bakker & Schaufeli, 2008; Grzywacz & Marks, 2000). This emerging focus supplements the dominant conflict perspective by identifying new ways of cultivating human resource strength

    Millimeter Interferometric HCN(1-0) and HCO+(1-0) Observations of Luminous Infrared Galaxies

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    We present the results on millimeter interferometric observations of four luminous infrared galaxies (LIRGs), Arp 220, Mrk 231, IRAS 08572+3915, and VV 114, and one Wolf-Rayet galaxy, He 2-10, using the Nobeyama Millimeter Array (NMA). Both the HCN(1-0) and HCO+(1-0) molecular lines were observed simultaneously and their brightness-temperature ratios were derived. High-quality infrared L-band (2.8-4.1 micron) spectra were also obtained for the four LIRGs to better constrain their energy sources deeply buried in dust and molecular gas. When combined with other LIRGs we have previously observed with NMA, the final sample comprised nine LIRGs (12 LIRGs' nuclei) with available interferometric HCN(1-0) and HCO+(1-0) data-sufficient to investigate the overall trend in comparison with known AGNs and starburst galaxies. We found that LIRGs with luminous buried AGN signatures at other wavelengths tend to show high HCN(1-0)/HCO+(1-0) brightness-temperature ratios as seen in AGN-dominated galaxies, while the Wolf-Rayet galaxy He 2-10 displays a small ratio. An enhanced HCN abundance in the interstellar gas surrounding a strongly X-ray-emitting AGN, as predicted by some chemical calculations, is a natural explanation of our results.Comment: 43 pages, 11 figures, accepted for publication in Astronomical Journal. Higher resolution version is available at http://optik2.mtk.nao.ac.jp/~imanishi/Paper/HCN2/HCN2.pd

    Identifying an Experimental Two-State Hamiltonian to Arbitrary Accuracy

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    Precision control of a quantum system requires accurate determination of the effective system Hamiltonian. We develop a method for estimating the Hamiltonian parameters for some unknown two-state system and providing uncertainty bounds on these parameters. This method requires only one measurement basis and the ability to initialise the system in some arbitrary state which is not an eigenstate of the Hamiltonian in question. The scaling of the uncertainty is studied for large numbers of measurements and found to be proportional to one on the square-root of the number of measurements.Comment: Minor corrections, Accepted for publication in Physical Review

    Immobile indices and CQ-free optimality criteria for linear copositive programming problems

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    We consider problems of linear copositive programming where feasible sets consist of vectors for which the quadratic forms induced by the corresponding linear matrix combinations are nonnegative over the nonnegative orthant. Given a linear copositive problem, we define immobile indices of its constraints and a normalized immobile index set. We prove that the normalized immobile index set is either empty or can be represented as a union of a finite number of convex closed bounded polyhedra. We show that the study of the structure of this set and the connected properties of the feasible set permits to obtain new optimality criteria for copositive problems. These criteria do not require the fulfillment of any additional conditions (constraint qualifications or other). An illustrative example shows that the optimality conditions formulated in the paper permit to detect the optimality of feasible solutions for which the known sufficient optimality conditions are not able to do this. We apply the approach based on the notion of immobile indices to obtain new formulations of regularized primal and dual problems which are explicit and guarantee strong duality.publishe

    Are nonsingular black holes with super-Planckian hair ruled out by S2 star data?

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    We propose a novel nonsingular black-hole spacetime representing a strong deformation of the Schwarzschild solution with mass MM by an additional hair \ell, which may be hierarchically larger than the Planck scale. Our black-hole model presents a de Sitter core and O(2/r2)\mathcal{O}(\ell^2/r^2) slow-decaying corrections to the Schwarzschild solution. Our black-hole solutions are thermodynamically preferred when 0.2/GM0.30.2 \lesssim \ell/GM \lesssim \, 0.3 and are characterized by strong deviations in the orbits of test particles from the Schwarzschild case. In particular, we find corrections to the perihelion precession angle scaling linearly with \ell. We test our model using the available data for the orbits of the S2 star around SgrA\text{SgrA}^*. These data strongly constrain the value of the hair \ell, casting an upper bound on it of 0.47GM\sim \, 0.47 \, GM, but do not rule out the possible existence of regular black holes with super-Planckian hair.Comment: 6 pages, 2 figures, 1 table. Revised version: Addendum and some references have been adde
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