4,379 research outputs found

    Millimeter and submillimeter wave technology developments for the next generation of fusion devices

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    There is increasing demand for compact watt-level coherent sources in the millimeter and submillimeter wave region. The approach that we have taken to satisfy this need is to fabricate two-dimensional grids loaded with oscillators, electronic beam steerers, and frequency multipliers for quasioptical coherent spatial combining of the outputs of a large number of low-power devices

    Optical properties of NaxV2O5

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    The optical properties of sodium-deficient NaxV2O5 (0.85 < x <1) single crystals are analyzed in the wide energy range, from 0.012 to 4.5 eV, using ellipsometry, infrared reflectivity, and Raman scattering techniques. The material remains insulating up to the maximal achieved hole concentration of about 15%. In sodium deficient samples the optical absorption peak associated to the fundamental electronic gap develops at about 0.44 eV. It corresponds to the transition between vanadium dxy and the impurity band, which forms in the middle of the pure NaV2O5 gap. Raman spectra measured with incident photon energy larger then 2 eV show strong resonant behavior, due to the presence of the hole-doping activated optical transitions, peaked at 2.8 eV.Comment: 7 pages, 4 fugures, to be published in PR

    PHILOSOPHERS ON BODY AND SPIRITUAL CULTURE

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    This study’s main focus on the view and the essential elements of physical and spiritual culture in philosopher’s works from ancient times until the end of the 20th century. This paper presents philosopher’s opinions on physical culture’s specific aspects, including physical education, sports, recreation and other border areas of the individual’s physical and spiritual activity. The references for this study on philosopher’s opinions are mainly from secondary sources. A concise statement of these philosopher’s work refers to the period before the New era, regarding Xenophanes, Socrates, Cliton, and Marcus Tallies Cicero. Then philosophers of the modern era, Francis Bacon and Rene Descartes, Jean-Jacques Rousseau, Immanuel Kant, Georg W.F. Hegel, Karl Marx, John Lobok, and the most prominent former Yugoslavs philosopher of the 20th century, Branislav Petronijevic. This study is not a critical review but a summary of the most influential thinkers’ views, from the historical aspect of the study preoccupation

    Domain-Specific Deep Learning Feature Extractor for Diabetic Foot Ulcer Detection

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    Diabetic Foot Ulcer (DFU) is a condition requiring constant monitoring and evaluations for treatment. DFU patient population is on the rise and will soon outpace the available health resources. Autonomous monitoring and evaluation of DFU wounds is a much-needed area in health care. In this paper, we evaluate and identify the most accurate feature extractor that is the core basis for developing a deep-learning wound detection network. For the evaluation, we used mAP and F1-score on the publicly available DFU2020 dataset. A combination of UNet and EfficientNetb3 feature extractor resulted in the best evaluation among the 14 networks compared. UNet and Efficientnetb3 can be used as the classifier in the development of a comprehensive DFU domain-specific autonomous wound detection pipeline.Comment: 5 pages, 2 figures, 3 tables, 2022 IEEE International Conference on Data Mining Workshop

    Shock Structure Analysis and Aerodynamics in a Weakly Ionized Gas Flow

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    The structure of a shock wave propagating through a weakly ionized gas is analyzed using an electrofluid dynamics model composed of classical conservation laws and Gauss Law. A viscosity model is included to correctly model the spatial scale of the shock structure, and quasi-neutrality is not assumed. A detailed analysis of the structure of a shock wave propagating in a weakly ionized gas is presented, together with a discussion of the physics underlying the key features of the shock structure. A model for the flow behind a shock wave propagating through a weakly ionized gas is developed and used to analyze the effect of the ionization on the aerodynamics and performance of a two-dimensional hypersonic lifting body

    Compression Tests on Cold-formed Angles Loaded Parallel with a Leg

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    This paper describes a series of compression tests on cold-formed equal angles with slender cross-section. The angles were tested between pinned ends and loaded axially with eccentric load which caused bending parallel with a leg. The test data are compared with the design rules of the Australian and American specifications for cold-formed and hot-rolled steel structures, as well as the ASCE Standard for the Design of Latticed Steel Transmission Structures. The rules of the specifications for cold-formed steel structures (AS/NZS4600 and AlSI) are shown to be very conservative. The cause of the conservatism is explained and improved design rules are proposed
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