347 research outputs found

    Fundamental Algorithms of the Goddard Battery Model

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    The Goddard Space Flight Center (GSFC) is currently producing a computer model to predict Nickel Cadmium (NiCd) performance in a Low Earth Orbit (LEO) cycling regime. The model proper is currently still in development, but the inherent, fundamental algorithms (or methodologies) of the model are defined. At present, the model is closely dependent on empirical data and the data base currently used is of questionable accuracy. Even so, very good correlations have been determined between model predictions and actual cycling data. A more accurate and encompassing data base has been generated to serve dual functions: show the limitations of the current data base, and be inbred in the model properly for more accurate predictions. The fundamental algorithms of the model, and the present data base and its limitations, are described and a brief preliminary analysis of the new data base and its verification of the model's methodology are presented

    Modeling Ni-Cd performance. Planned alterations to the Goddard battery model

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    The Goddard Space Flight Center (GSFC) currently has a preliminary computer model to simulate a Nickel Cadmium (Ni-Cd) performance. The basic methodology of the model was described in the paper entitled Fundamental Algorithms of the Goddard Battery Model. At present, the model is undergoing alterations to increase its efficiency, accuracy, and generality. A review of the present battery model is given, and the planned charges of the model are described

    Dimensions of aging and their influence on physical activity = Wymiary starzenia i ich wpływ na aktywność fizyczną

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    Podhorecka M., Główczewska J., Ciesielska N., Gębka D., Sokołowski R., Szymańska A., Jagielski D., Zukow W. Dimensions of aging and their influence on physical activity = Wymiary starzenia i ich wpływ na aktywność fizyczną. Journal of Education, Health and Sport. 2015;5(12):230-239. ISSN 2391-8306. DOIhttp://dx.doi.org/10.5281/zenodo.35365http://ojs.ukw.edu.pl/index.php/johs/article/view/2015%3B5%2812%29%3A230-239http://pbn.nauka.gov.pl/works/680050Formerly Journal of Health Sciences. ISSN 1429-9623 / 2300-665X. Archives 2011–2014http://journal.rsw.edu.pl/index.php/JHS/issue/archive Deklaracja.Specyfika i zawartość merytoryczna czasopisma nie ulega zmianie.Zgodnie z informacją MNiSW z dnia 2 czerwca 2014 r., że w roku 2014 nie będzie przeprowadzana ocena czasopism naukowych; czasopismo o zmienionym tytule otrzymuje tyle samo punktów co na wykazie czasopism naukowych z dnia 31 grudnia 2014 r.                                           The journal has had 5 points in Ministry of Science and Higher Education of Poland parametric evaluation. Part B item 1089. (31.12.2014).© The Author (s) 2015;This article is published with open access at Licensee Open Journal Systems of Kazimierz Wielki University in Bydgoszcz, Poland and Radom University in Radom, PolandOpen Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium,provided the original author(s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License(http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited.This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non commercialuse, distribution and reproduction in any medium, provided the work is properly cited.The authors declare that there is no conflict of interests regarding the publication of this paper.Received: 10.11.2015. Revised 25.11.2015. Accepted: 14.12.2015. Dimensions of aging and their influence on physical activityWymiary starzenia i ich wpływ na aktywność fizyczną M. Podhorecka1, J. Główczewska1, N. Ciesielska1, D. Gębka1, R. Sokołowski2, A. Szymańska1, D. Jagielski1, W. Zukow3 1Katedra i Klinika Geriatrii, Collegium Medicum UMK, Toruń, Bydgoszcz, Polska/ Nicolaus Copernicus University in Toruń, Collegium Medicum in Bydgoszcz, Department of Geriatrics, Poland2Katedra Higieny, Epidemiologii i Ergonomii , Collegium Medicum UMK, Toruń,Bydgoszcz, Polska/ Nicolaus Copernicus University in Toruń, Collegium Medicum in Bydgoszcz, Department of Hygiene and Epidemiology, Poland3Wydział Kultury Fizycznej, Zdrowia i Turystyki, Uniwersytet Kazimierza Wielkiego w Bydgoszczy, Polska/ Faculty of Physical Education, Health and Tourism, Kazimierz Wielki University, Bydgoszcz, Poland AbstractOld age is a common and a universal phenomenon. It is difficult to define the beginning of the process of aging and entering the period of late adulthood. As time passes, the symptoms of aging become more and more visible. The work presents three dimensions of aging: biological, psychological and social. It demonstrates their influence on physical activity. It shows  barriers the elderly people need to overcome or the situations they might be in. It also shows physical activity as one of the main components of the activation process of the elderly.Key words: elderly, physical activity, aging

    Polar bears are inefficient predators of seabird eggs

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    Climate-mediated sea-ice loss is disrupting the foraging ecology of polar bears (Ursus maritimus) across much of their range. As a result, there have been increased reports of polar bears foraging on seabird eggs across parts of their range. Given that polar bears have evolved to hunt seals on ice, they may not be efficient predators of seabird eggs. We investigated polar bears\u27 foraging performance on common eider (Somateria mollissima) eggs on Mitivik Island, Nunavut, Canada to test whether bear decision-making heuristics are consistent with expectations of optimal foraging theory. Using aerial-drones, we recorded multiple foraging bouts over 11 days, and found that as clutches were depleted to completion, bears did not exhibit foraging behaviours matched to resource density. As the season progressed, bears visited fewer nests overall, but marginally increased their visitation to nests that were already empty. Bears did not display different movement modes related to nest density, but became less selective in their choice of clutches to consume. Lastly, bears that capitalized on visual cues of flushing eider hens significantly increased the number of clutches they consumed; however, they did not use this strategy consistently or universally. The foraging behaviours exhibited by polar bears in this study suggest they are inefficient predators of seabird eggs, particularly in the context of matching behaviours to resource density

    Efficient Blue Electroluminescence Using Quantum-Confined Two-Dimensional Perovskites

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    Solution-processed hybrid organic–inorganic lead halide perovskites are emerging as one of the most promising candidates for low-cost light-emitting diodes (LEDs). However, due to a small exciton binding energy, it is not yet possible to achieve an efficient electroluminescence within the blue wavelength region at room temperature, as is necessary for full-spectrum light sources. Here, we demonstrate efficient blue LEDs based on the colloidal, quantum-confined 2D perovskites, with precisely controlled stacking down to one-unit-cell thickness (<i>n</i> = 1). A variety of low-<i>k</i> organic host compounds are used to disperse the 2D perovskites, effectively creating a matrix of the dielectric quantum wells, which significantly boosts the exciton binding energy by the dielectric confinement effect. Through the Förster resonance energy transfer, the excitons down-convert and recombine radiatively in the 2D perovskites. We report room-temperature pure green (<i>n</i> = 7–10), sky blue (<i>n</i> = 5), pure blue (<i>n</i> = 3), and deep blue (<i>n</i> = 1) electroluminescence, with record-high external quantum efficiencies in the green-to-blue wavelength region

    Efficient perovskite nanocrystal light-emitting diodes using a benzimidazole-substituted anthracene derivative as the electron transport material

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    Colloidal nanocrystals of organic–inorganic hybrid perovskites (OIHPs) are an emerging class of solid-state lighting materials owing to their outstanding photophysical properties. Considerable research efforts have been devoted to the fabrication of high-performance light-emitting diodes (LEDs) based on these materials, including interface engineering which is essential for balancing the electron and hole injection in devices. Here, we report efficient perovskite nanocrystal LEDs based on a new electron transport material (ETM), 9,10-bis(N-benzimidazolyl)anthracene (BBIA), possessing a high electron mobility of 4.17 × 10−4 cm2 V−1 s−1 at an electric field of 105 V cm−1. Compared to control devices based on the ETM 2,2′,2′′-(1,3,5- benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi), BBIA-based devices exhibit a nearly two-fold enhancement, increasing the current and external quantum efficiencies from 6.25 cd A−1 and 1.51% to 12.2 cd A−1 and 2.96%, respectively. In addition, a small degree of efficiency roll-off of 8 ± 1% at a luminance of 2000 cd m−2, as well as a low turn-on voltage of 2.35 V, has been demonstrated. The anthracene-based compounds may open up new research opportunities for interface engineering in perovskite LEDs

    Search for non-relativistic Magnetic Monopoles with IceCube

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    The IceCube Neutrino Observatory is a large Cherenkov detector instrumenting 1km31\,\mathrm{km}^3 of Antarctic ice. The detector can be used to search for signatures of particle physics beyond the Standard Model. Here, we describe the search for non-relativistic, magnetic monopoles as remnants of the GUT (Grand Unified Theory) era shortly after the Big Bang. These monopoles may catalyze the decay of nucleons via the Rubakov-Callan effect with a cross section suggested to be in the range of 1027cm210^{-27}\,\mathrm{cm^2} to 1021cm210^{-21}\,\mathrm{cm^2}. In IceCube, the Cherenkov light from nucleon decays along the monopole trajectory would produce a characteristic hit pattern. This paper presents the results of an analysis of first data taken from May 2011 until May 2012 with a dedicated slow-particle trigger for DeepCore, a subdetector of IceCube. A second analysis provides better sensitivity for the brightest non-relativistic monopoles using data taken from May 2009 until May 2010. In both analyses no monopole signal was observed. For catalysis cross sections of 1022(1024)cm210^{-22}\,(10^{-24})\,\mathrm{cm^2} the flux of non-relativistic GUT monopoles is constrained up to a level of Φ901018(1017)cm2s1sr1\Phi_{90} \le 10^{-18}\,(10^{-17})\,\mathrm{cm^{-2}s^{-1}sr^{-1}} at a 90% confidence level, which is three orders of magnitude below the Parker bound. The limits assume a dominant decay of the proton into a positron and a neutral pion. These results improve the current best experimental limits by one to two orders of magnitude, for a wide range of assumed speeds and catalysis cross sections.Comment: 20 pages, 20 figure

    Determining neutrino oscillation parameters from atmospheric muon neutrino disappearance with three years of IceCube DeepCore data

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    We present a measurement of neutrino oscillations via atmospheric muon neutrino disappearance with three years of data of the completed IceCube neutrino detector. DeepCore, a region of denser instrumentation, enables the detection and reconstruction of atmospheric muon neutrinos between 10 GeV and 100 GeV, where a strong disappearance signal is expected. The detector volume surrounding DeepCore is used as a veto region to suppress the atmospheric muon background. Neutrino events are selected where the detected Cherenkov photons of the secondary particles minimally scatter, and the neutrino energy and arrival direction are reconstructed. Both variables are used to obtain the neutrino oscillation parameters from the data, with the best fit given by Δm322=2.720.20+0.19×103eV2\Delta m^2_{32}=2.72^{+0.19}_{-0.20}\times 10^{-3}\,\mathrm{eV}^2 and sin2θ23=0.530.12+0.09\sin^2\theta_{23} = 0.53^{+0.09}_{-0.12} (normal mass hierarchy assumed). The results are compatible and comparable in precision to those of dedicated oscillation experiments.Comment: 10 pages, 7 figure

    Atmospheric and Astrophysical Neutrinos above 1 TeV Interacting in IceCube

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    The IceCube Neutrino Observatory was designed primarily to search for high-energy (TeV--PeV) neutrinos produced in distant astrophysical objects. A search for 100\gtrsim 100~TeV neutrinos interacting inside the instrumented volume has recently provided evidence for an isotropic flux of such neutrinos. At lower energies, IceCube collects large numbers of neutrinos from the weak decays of mesons in cosmic-ray air showers. Here we present the results of a search for neutrino interactions inside IceCube's instrumented volume between 1~TeV and 1~PeV in 641 days of data taken from 2010--2012, lowering the energy threshold for neutrinos from the southern sky below 10 TeV for the first time, far below the threshold of the previous high-energy analysis. Astrophysical neutrinos remain the dominant component in the southern sky down to 10 TeV. From these data we derive new constraints on the diffuse astrophysical neutrino spectrum, Φν=2.060.3+0.4×1018(Eν/105GeV)2.46±0.12GeV1cm2sr1s1\Phi_{\nu} = 2.06^{+0.4}_{-0.3} \times 10^{-18} \left({E_{\nu}}/{10^5 \,\, \rm{GeV}} \right)^{-2.46 \pm 0.12} {\rm {GeV^{-1} \, cm^{-2} \, sr^{-1} \, s^{-1}} } , as well as the strongest upper limit yet on the flux of neutrinos from charmed-meson decay in the atmosphere, 1.52 times the benchmark theoretical prediction used in previous IceCube results at 90\% confidence.Comment: 18 pages, 12 figure
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