25,073 research outputs found
Retrofitting Catenary-Powered Transport Systems Toward Greater Electrification
No full textElectric transportation is expected to play an important part in the urban energy transition as catenary-powered networks become more widely deployed. However, technological problems must be overcome to ensure that current networks can be used successfully without sacrificing vehicle performance and network technical compliance. This research seeks to justify the usage of battery energy storage systems (BESS) as a retrofitting solution for catenary-powered traction networks. The goal is to strengthen the network without compromising overall operational efficiency, allowing additional electrification projects to be executed using the same network infrastructure without significant changes. To achieve this objective, solutions using second-life batteries (SLB) are compared with scenarios involving new batteries and alternative strategies, such as reinforcing critical catenary points and implementing voltage regulation in substations. The results show that, although SLBs from decommissioned vehicles present a viable solution, they require battery capacities at least four times greater than those needed for solutions using new batteries
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
F. R. Leavis: The Creative University
No full textThis is a critical introduction to the educational thought of F. R. Leavis (1895-1978), the greatest English literary critic of the twentieth century, providing the first in-depth examination of Leavis's ideas in relation to contemporary mass higher education. During the course of a long, prolific and controversial academic career, which saw him take issue with figures such as Wittgenstein, T. S. Eliot and C. P. Snow, Leavis became one of the most articulate advocates for the idea of the university as 'a centre of consciousness and human responsibility' in the face of what he saw as the relentless technological drive of civilisation. With the journal Scrutiny which he co-founded, as well as his critical writings, Leavis became a decisive influence on generations of teachers in Britain and overseas. Widely misrepresented as narrowly elitist, his ideas about 'the creative university', with their radical, student-centred approach to teaching, constitute a powerful resource for a higher education system grappling with the contradictory demands of continuity and change. Based on original research, the study provides an overview of Leavis's life, work and heritage and his educational world view, and a comprehensive exploration of Leavis's pedagogy from theoretical and practical perspectives. It also includes a first-hand account by the author of being taught by Leavis in person
The L-p-to-L-q boundedness of commutators with applications to the Jacobian operator
No full textSupplying the missing necessary conditions, we complete the characterisation of the L-p -> L-q boundedness of commutators [b, T] of pointwise multiplication and Calderon-Zygmund operators, for arbitrary pairs of 1 q, our results are new even for special classical operators with smooth kernels. As an application, we show that every f is an element of L-p(R-d) can be represented as a convergent series of normalised Jacobians J(u) = det del uof u is an element of (over dot(W))(1,dp)(R-d)(d). This extends, from p = 1 to p > 1, a result of Coifman, Lions, Meyer and Semmes about J:. (over dot(W))(1,d)(R-d)(d) -> H-1(R-d), and supports a conjecture of Iwaniec about the solvability of the equation Ju = f is an element of L-p(R-d). (C) 2021 The Author(s). Published by Elsevier Masson SAS.Peer reviewe
Long range potential effects in low density krypton gas
No full textSmall angle neutron scattering (SANS) in low density Kr-86 gas has been performed in order to measure the small-k behavior of the static structure factor S(k). Three number densities between 1.52 and 2.42 nm(-3) along the T = 297 K isotherm have been studied. The small-k dependence of the Fourier transform c(k) of the direct correlation function c(r) has been derived. The experimental determination of the k(3) term in the behavior of c(k) has led to a direct measurement of the London dispersion interaction in the pair potential of krypton. Also the contribution of the three-body potential in the asymptotic behavior of c(r) has been observed and related to the magnitude of the three-body interaction potential
On an asymptotically p-linear p-Laplacian equation in R-N
No full textIn this paper, we study the existence of positive solutions and sign-changing solutions for the p-Laplacian equation -Delta(p)u + lambda g(x) vertical bar u vertical bar(p-2) u = f(x, u), x is an element of R-N, where lambda is a positive parameter and the nonlinear term f is superlinear at zero and asymptotically p-linear at infinity. (C) 2010 Elsevier Ltd. All rights reserved.Mathematics, AppliedMathematicsSCI(E)EI2ARTICLE2676-6887
Cosmology in modified f(R, T)-gravity
No full text© 2018, The Author(s). In the present paper we propose a further modification of f(R, T)-gravity (where T is trace of the energy-momentum tensor) by introducing higher derivatives matter fields. We discuss stability conditions in the proposed theory and find restrictions for the parameters to prevent appearance of main type of instabilities, such as ghost-like and tachyon-like instabilities. We derive cosmological equations for a few representations of the theory and discuss main differences with conventional f(R, T)-gravity without higher derivatives. It is demonstrated that in the theory presented inflationary scenarios appear quite naturally even in the dust-filled Universe without any additional matter sources. Finally, we construct an inflationary model in one of the simplest representation of the theory, calculate the main inflationary parameters and find that it may be in quite good agreement with observations
Correlated hyperfine interactions in amorphous Cr72-xFexC17Si8Al3 alloys
No full textPT: J; CR: BAHADUR D, 1987, J MATER SCI, V22, P2477 DINI K, 1986, J MATER SCI, V21, P1037 DUNLAP RA, 1982, CAN J PHYS, V60, P909 DUNLAP RA, 1985, J MATER SCI LETT, V4, P773 EIBSCHUTZ M, 1983, PHYS REV B, V28, P425 INGALLS R, 1978, MOSSBAUER ISOMER SHI, P361 LECAER G, 1979, J PHYS E SCI INSTRUM, V12, P1083 OLIVIER M, 1982, J APPL PHYS, V53, P7696 POLLARD RJ, 1984, PHYS REV B, V29, P4864 YU BL, 1984, J APPL PHYS, V55, P1748; NR: 10; TC: 10; J9: J PHYS-F-METAL PHYS; PG: 8; GA: R0716Source type: Electronic(1
Cosmology in modified f(R, T)-gravity
No full text© 2018, The Author(s). In the present paper we propose a further modification of f(R, T)-gravity (where T is trace of the energy-momentum tensor) by introducing higher derivatives matter fields. We discuss stability conditions in the proposed theory and find restrictions for the parameters to prevent appearance of main type of instabilities, such as ghost-like and tachyon-like instabilities. We derive cosmological equations for a few representations of the theory and discuss main differences with conventional f(R, T)-gravity without higher derivatives. It is demonstrated that in the theory presented inflationary scenarios appear quite naturally even in the dust-filled Universe without any additional matter sources. Finally, we construct an inflationary model in one of the simplest representation of the theory, calculate the main inflationary parameters and find that it may be in quite good agreement with observations
Measurement of the polarization amplitudes and triple product asymmetries in the B0s → Φ Φ decay
No full text<p>Using 1.0 fb−1 of pp collision data collected at a centre-of-mass energy of s√=7 TeV with the LHCb detector, measurements of the polarization amplitudes, strong phase difference and triple product asymmetries in the B0s→ϕϕ decay mode are presented. The measured values are</p>
<p>|A0|2=0.365±0.022(stat)±0.012(syst),|A⊥|2=0.291±0.024(stat)±0.010(syst),cos(δ∥)=−0.844±0.068(stat)±0.029(syst),AU=−0.055±0.036(stat)±0.018(syst),AV=0.010±0.036(stat)±0.018(syst).</p>
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