cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Non-destructive detection of corrosion of epoxy coated rebar
Creators: name: Goffin, Brigitte
Publisher: name: University of British Columbia
Year: 2018

description: Deteriorating infrastructure is an acute and dangerous problem, which is often caused by the corrosion of concrete reinforcement. Marine structures and bridge decks, where sea water and de-icing salts lead to chloride ion diffusion into the concrete are particularly at risk. Epoxy coated rebar (ECR) is a popular choice for the latter structures. However, corrosion of ECR, which occurs due to coating damage, poses a challenge to non-destructive corrosion detection. This study investigated the corrosion behaviour, accelerated corrosion and non-destructive corrosion detection of ECR. The electrochemical corrosion behaviour of ECR in simulated concrete pore solutions was studied and compared to uncoated rebar (UCR). The polarized area of ECR was related but not proportional to the sodium ion concentration of the test solution. Furthermore, ECR was more susceptible to corrosion than UCR, particularly in the presence of NaCl and in NaHCO₃ solution. A test solution of Na2CO₃ and NaHCO₃ led to the formation of a very fragile passive layer, that grew slowly but continuously. However, the protective layer was sensitive to even small amounts of NaCl. Corrosion of ECR was accelerated in neutral and alkaline NaCl solutions as well as in concrete. Neutral and alkaline environments promoted coating holiday and undercoating corrosion, respectively. Part of the undercoating corrosion process was cathodic delamination, whose acceleration prior to corrosion acceleration slowed down the lateral corrosion expansion. Once corrosion had expanded across the entire surface, the subsequent corrosion rate was not affected by the initial cathodic disbondment. Successful ECR corrosion detection was limited with the linear polarization resistance and ground penetrating radar method. However, concrete properties such as maturity, moisture and chloride content had a significant effect on the measurements. Corroded bars affected the Hall effect (HE) voltage to a lesser extent than intact rebar. Furthermore, corrosion of ECR led to higher concrete surface and lower bar temperatures during active infrared thermography (IRT) tests. The thermal results of ECR opposed those of UCR. The HE and IRT tests showed that the effects of corrosion on the thermal and magnetic behaviour during induction thermography would complement and oppose each other for UCR and ECR respectively.
Spatially Resolved Manipulation of Single Electrons in Quantum Dots Using a Scanned Probe
Creators: name: Pioda, A.
name: Kičin, S.
name: Ihn, Thomas
name: Sigrist, Martin
name: Fuhrer, A.
name: Ensslin, Klaus
name: Weichselbaum, A.
name: Ulloa, S. E.
name: Reinwald, Matthias
name: Wegscheider, Werner
Publisher: name: Universität Regensburg
Year: 2004
Subjects: subject: 530 Physik
subject: 73.23.–b, 07.79.–v

description: The scanning metallic tip of a scanning force microscope was coupled capacitively to electrons confined in a lithographically defined gate-tunable quantum dot at a temperature of 300 mK. Single electrons were made to hop on or off the dot by moving the tip or by changing the tip bias voltage owing to the Coulomb-blockade effect. Spatial images of conductance resonances map the interaction potential between the tip and individual electronic quantum dot states. Under certain conditions this interaction is found to contain a tip-voltage induced and a tip-voltage-independent contribution.
Dual Jets from Binary Black Holes
Creators: name: Palenzuela, Carlos
name: Lehner, Luis
name: Liebling, Steven L.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Supermassive black holes are found at the centers of most galaxies and their inspiral is a natural outcome when galaxies merge. The inspiral of these systems is of utmost astrophysical importance as prodigious producers of gravitational waves and in their possible role in energetic electromagnetic events. We study such binary black hole coalescence under the influence of an external magnetic field produced by the expected circumbinary disk surrounding them. Solving the Einstein equations to describe the spacetime and using the force-free approach for the electromagnetic fields and the tenuous plasma, we present numerical evidence for possible jets driven by these systems. Extending the process described by Blandford and Znajek for a single spinning black hole, the picture that emerges suggests the electromagnetic field extracts energy from the orbiting black holes, which ultimately merge and settle into the standard Blandford-Znajek scenario. Emissions along dual and single jets would be expected that could be observable to large distances.
description: 6 pages, 4 figures
Existence of energy-minimal diffeomorphisms between doubly connected domains
Creators: name: Iwaniec, Tadeusz
name: Koh, Ngin-Tee
name: Kovalev, Leonid V.
name: Onninen, Jani
Publisher: name: arXiv
Year: 2010
Subjects: subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: 58E20, 30C62, 31A05

description: The paper establishes the existence of homeomorphisms between two planar domains that minimize the Dirichlet energy. Specifically, among all homeomorphisms f : R -> R* between bounded doubly connected domains such that Mod (R) < Mod (R*) there exists, unique up to conformal authomorphisms of R, an energy-minimal diffeomorphism. No boundary conditions are imposed on f. Although any energy-minimal diffeomorphism is harmonic, our results underline the major difference between the existence of harmonic diffeomorphisms and the existence of the energy-minimal diffeomorphisms. The existence of globally invertible energy-minimal mappings is of primary pursuit in the mathematical models of nonlinear elasticity and is also of interest in computer graphics.
description: 34 pages, no figures
Surface treatments and magnetic properties of Ga1−xMnxAs thin films
Creators: name: Maccherozzi, F.
name: Panaccione, G.
name: Rossi, G.
name: Hochstrasser, M.
name: Sperl, Matthias
name: Reinwald, Matthias
name: Woltersdorf, Georg
name: Wegscheider, Werner
name: Back, Christian
Publisher: name: Universität Regensburg
Year: 2007
Subjects: subject: X-ray photoelectron spectroscopy; X-ray absorption spectroscopy; Magnetic interfaces; (Ga,Mn)As
subject: 530 Physik

description: As a diluted magnetic semiconductor (DMS), (Ga,Mn)As is a possible candidate for the realization of spintronics devices, due to its intrinsic compatibility with GaAs based electronics. The low Curie temperature still limits its use for practical devices. Despite the huge knowledge on GaAs surface, the (Ga,Mn)As surface is still not well understood and difficult to handle. Standard surface cleaning techniques have many drawbacks, mainly because thermal treatments changes crystal structure. We will compare the magnetic and spectroscopic properties of differently processed (Ga,Mn)As surfaces with X-ray photoemission (XPS), X-ray absorption (XAS) and X-ray magnetic circular dichroism (XMCD). Samples as-grown, chemically etched, Ar+ sputtered and annealed in oxygen will be compared.
Ambient modal identification, finite element model updating, and seismic analysis of bridges on Trans-Canada Highway
Creators: name: Khan, Bahram
Publisher: name: University of British Columbia
Year: 2018

description: This thesis features finite element model updating of two short-span concrete bridges, namely Gaglardi Way Underpass and Kensington Avenue Underpass. The main objective was to study the effect and determine the importance of finite element model updating by comparing the structural responses for the updated model to the preliminary model. The study was carried out by developing a finite element (FE) model and an operational modal analysis (OMA) model for each bridge. The FE model represented the analytical prototype of the actual structure, while the OMA model was used to extract the modal information for existing structure using the vibration data recorded under normal operating conditions from permanent sensors installed on corners and at mid-span of these bridges. The natural frequencies from OMA were set as a target for the FE model to match. The process of calibrating the analytical FE model to the match the modal information acquired from the experimental model is known as ‘Model Updating’. Having the frequency responses defined, a sensitivity analysis was conducted to determine the parameters that are most sensitive to change, based on which the FE model was automatically updated in an iterative manner. The modal assurance criterion (MAC) and mode shape responses were not used during calibration step since the vibration testing was not dense enough, however, they were solely used as a means of comparing the calibrated FE model to the experimental results. Once the objective of model updating was accomplished, a linear modal time history analysis was carried out using three ground motions having a low, medium range, and a very high peak ground acceleration (PGA), in addition to a fourth very low ambient level ground motion. Comparing the resulting absolute maximum base reactions and the mid-span structural displacements from updated model to the original model, it was concluded that the percentage changes were significantly high, therefore, the chance of original model being uncertain is very high for which model updating is an important and a highly effective technique, where possible, to generate a high confidence FE model that in best possible manner represents the behaviour of an actual structure.
Low-Magnetic-Field Divergence of the Electronic g Factor Obtained from the Cyclotron Spin-Flip Mode of the ν=1 Quantum Hall Ferromagnet
Creators: name: Vankov, A. B.
name: Kulik, L. V.
name: Kukushkin, I. V.
name: Kirpichev, V. E.
name: Dickmann, S.
name: Zhilin, V. M.
name: Smet, J. H.
name: Klitzing, Klaus von
name: Wegscheider, Werner
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: 530 Physik
subject: 73.43.Lp, 71.70.Ej, 75.30.Ds

description: We report an inelastic light scattering study of the cyclotron spin-flip mode in the two-dimensional electron system at filling ν=1. The energy of this mode can serve as a probe of the many-body exchange interaction on short length scales. Its magnetic field dependence is compared with predictions based on Hartree-Fock theory. They agree well when including the nonzero width of the electron system. From the measured energies, the exchange enhanced g factor is extracted. It diverges at small fields and differs largely from g factors obtained via transport activation studies.
Characterizing Spam traffic and Spammers
Creators: name: Dhinakaran, Cynthia
name: Nagamalai, Dhinaharan
name: Lee, Jae Kwang
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cryptography and Security (cs.CR)
subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: There is a tremendous increase in spam traffic these days. Spam messages muddle up users inbox, consume network resources, and build up DDoS attacks, spread worms and viruses. Our goal is to present a definite figure about the characteristics of spam and spammers. Since spammers change their mode of operation to counter anti spam technology,continues evaluation of the characteristics of spam and spammers technology has become mandatory. These evaluations help us to enhance the existing technology to combat spam effectively. We collected 400 thousand spam mails from a spam trap set up in a corporate mail server for a period of 14 months form January 2006 to February 2007. Spammers use common techniques to spam end users regardless of corporate server and public mail server. So we believe that our spam collection is a sample of world wide spam traffic. Studying the characteristics of this sample helps us to better understand the features of spam and spammers technology. We believe that this analysis could be useful to develop more efficient anti spam techniques.
description: 6 pages, 4 Figures, ICCIT 2007, IEEE CS
The role of density imbalance in the vT = 1 exciton condensate state for electron bilayer systems
Creators: name: Wiersma, R. D.
name: Lok, J. G. S.
name: Dietsche, W.
name: Klitzing, Klaus von
name: Schuh, Dieter
name: Wegscheider, Werner
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: 530 Physik
subject: 71.35.Lk; 73.43.-f; 73.50.Jt

description: We report on our experimental work involving the T = 1 exciton condensate in independently contacted bilayer two-dimensional electron systems. A phase diagram between the weakly coupled ( U = 1/2, L = 1/2) phase and the strongly coupled T = 1 phase is experimentally investigated as a function of d /B and electron density imbalance n ( [n L - n U]/n T) using a drag current configuration. For imbalanced electron layer densities, small interlayer imbalances lead to strengthening of the excitonic phase. Here density imbalance leads to a phase boundary in the drag layer which is symmetric around zero imbalance. Surprisingly this behavior is not seen for drive,xx , where an unusual asymmetric behavior around zero imbalance occurs. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Architecture of A Scalable Dynamic Parallel WebCrawler with High Speed Downloadable Capability for a Web Search Engine
Creators: name: Mukhopadhyay, Debajyoti
name: Mukherjee, Sajal
name: Ghosh, Soumya
name: Kar, Saheli
name: Kim, Young-Chon
Publisher: name: arXiv
Year: 2011
Subjects: subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: Today World Wide Web (WWW) has become a huge ocean of information and it is growing in size everyday. Downloading even a fraction of this mammoth data is like sailing through a huge ocean and it is a challenging task indeed. In order to download a large portion of data from WWW, it has become absolutely essential to make the crawling process parallel. In this paper we offer the architecture of a dynamic parallel Web crawler, christened as "WEB-SAILOR," which presents a scalable approach based on Client-Server model to speed up the download process on behalf of a Web Search Engine in a distributed Domain-set specific environment. WEB-SAILOR removes the possibility of overlapping of downloaded documents by multiple crawlers without even incurring the cost of communication overhead among several parallel "client" crawling processes.
description: 6 pages, 6 figures
title: Konzept zur Überwachung und Assistenz von Mensch-Maschine Systemen am Beispiel der kooperativen Durchführung eines Praktikumsversuches zur Regelung eines Drei-Tank-Systems
Creators: name: Dylla, Eike
name: Rehder, Tobias
name: Helker, Stefan
name: Fu, Xingguang
name: Söffker, Dirk
Publisher: name: DuEPublico: Duisburg-Essen Publications Online, University of Duisburg-Essen, Germany
Year: 2013

description: Zur Kooperation von an verschiedenen Orten verteilten, gemeinsam arbeitenden,

Nutzerinnen und Nutzern von Mensch-Maschine Systemen, sind geeignete technischinformatorische

Module zu entwickeln. Die kooperative, online- und echtzeitfahige Regelung

eines Drei-Tank-Systems, welche als Praktikumsversuch fur Studierende zum Einsatz kommt,

soll minimalprototypisch die Gesamtfunktionalitat abbilden. Die Versuchsstandsdaten sollen

an die bedienenden Personen in Echtzeit ubermittelt werden und so die Kommunikation mit

den durchfuhrenden Studierenden ermoglichen. Hierzu mussen geeignete Werkzeuge entwickelt

werden. Das Konzept sieht vor, das Drei-Tank System mit einem PC zu verbinden, welcher

die Software NI LabVIEW nutzt. Der PC ist gleichzeitig mit dem Internet verbunden und es

wird eine HTML-Seite als Interface zur Verfugung gestellt. Die Datenaus- und eingabe und

Kommunikation, in Form einer Chat Funktion, werden entsprechend ermoglicht. Zusatzlich

werden Warnungen und Hinweise im Sinne der Assistenz und Uberwachung integriert.
Herschel and SCUBA-2 imaging and spectroscopy of a bright, lensed submillimetre galaxy at z = 2.3
Creators: name: Ivison, R. J.
name: Swinbank, A. M.
name: Swinyard, B.
name: Smail, Ian
name: Pearson, C. P.
name: Rigopoulou, D.
name: Polehampton, E.
name: Baluteau, J. -P.
name: Barlow, M. J.
name: Blain, A. W.
name: Bock, J.
name: Clements, D. L.
name: Coppin, K.
name: Cooray, A.
name: Danielson, A.
name: Dwek, E.
name: Edge, A. C.
name: Franceschini, A.
name: Fulton, T.
name: Glenn, J.
name: Griffin, M.
name: Isaak, K.
name: Leeks, S.
name: Lim, T.
name: Naylor, D.
name: Oliver, S. J.
name: Page, M. J.
name: Perez-Fournon, I.
name: Rowan-Robinson, M.
name: Savini, G.
name: Scott, D.
name: Spencer, L.
name: Valtchanov, I.
name: Vigroux, L.
name: Wright, G. S.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present a detailed analysis of the far-IR properties of the bright, lensed, z = 2.3, SMG, SMM J2135-0102, using new observations with Herschel, SCUBA-2 and the VLA. These data allow us to constrain the galaxy's SED and show that it has an intrinsic rest-frame 8-1000um luminosity, L(bol), of (2.3 +/- 0.2) x 10^12 L(sun) and a likely SFR of ~400 M(sun)/yr. The galaxy sits on the far-IR/radio correlation for far-IR-selected galaxies. At ~>70um, the SED can be described adequately by dust components with T(d) ~ 30 and 60K. Using SPIRE's Fourier Transform Spectrometer we report a detection of the [CII] 158um cooling line. If the [CII], CO and far-IR continuum arise in photo-dissociation regions, we derive a characteristic gas density, n ~ 10^3 cm^-3, and a far-UV radiation field, G_0, 10^3x stronger than the Milky Way. L([CII])/L(bol) is significantly higher than in local ULIRGs but similar to the values found in local star-forming galaxies and starburst nuclei. This is consistent with SMM J2135-0102 being powered by starburst clumps distributed across ~2 kpc, evidence that SMGs are not simply scaled-up ULIRGs. Our results show that SPIRE's FTS has the ability to measure the redshifts of distant, obscured galaxies via the blind detection of atomic cooling lines, but it will not be competitive with ground-based CO-line searches. It will, however, allow detailed study of the integrated properties of high-redshift galaxies, as well as the chemistry of their ISM, once more suitably bright candidates have been found.
description: A&A Herschel Special Issue, in press as a Letter. 5 pages, 3 colour figures
Conversion of Spin into Directed Electric Current in Quantum Wells
Creators: name: Ganichev, Sergey
name: Ivchenko, Eougenious
name: Danilov, Sergey
name: Eroms, Jonathan
name: Wegscheider, Werner
name: Weiss, Dieter
name: Prettl, Wilhelm
Publisher: name: Universität Regensburg
Year: 2001
Subjects: subject: 530 Physik
subject: 73.50.Mx, 68.65.-k, 73.50.Pz, 78.30.Fs

description: A nonequilibrium population of spin-up and spin-down states in quantum well structures has been achieved applying circularly polarized radiation. The spin polarization results in a directed motion of free carriers in the plane of a quantum well perpendicular to the direction of light propagation. Because of the spin selection rules the direction of the current is determined by the helicity of the light and can be reversed by switching the helicity from right to left handed. A microscopic model is presented which describes the origin of the photon helicity driven current. The model suggests that the system behaves as a battery which generates a spin polarized current.
Optical gain, carrier-induced phase shift, and linewidth enhancement factor in InGaN quantum well lasers
Creators: name: Schwarz, Ulrich
name: Sturm, Evi
name: Wegscheider, Werner
name: Kümmler, V.
name: Lell, Alfred
name: Härle, Volker
Publisher: name: Universität Regensburg
Year: 2003
Subjects: subject: refractive index, quantum well lasers, spectral line breadth, indium compounds, gallium compounds, III-V semiconductors, semiconductor quantum wells
subject: 530 Physik
subject: 42.55.Px; 78.20.Ci; 85.35.Be; 78.67.De

description: Adapting the Hakki Paoli method to group III nitrides, we measure gain, differential gain, carrier-induced change of refractive index, carrier-induced phase shift, and the antiguiding factor. Our measurements also cover the low-carrier-density regime, in which spontaneous and piezoelectric fields and Coulomb interaction are only partially screened. This regime is most interesting as a comparison with existing theoretical simulations, including many-body effects.
The spectrum of static-light baryons in twisted mass lattice QCD
Creators: name: Wagner, Marc
name: Wiese, Christian
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We compute the static-light baryon spectrum with N_f = 2 flavors of sea quarks using Wilson twisted mass lattice QCD. As light valence quarks we consider quarks, which have the same mass as the sea quarks with corresponding pion masses in the range 340 MeV < m_PS < 525 MeV, as well as partially quenched quarks, which have the mass of the physical s quark. We extract masses of states with isospin I = 0, 1/2, 1, with strangeness S = 0, -1, -2, with angular momentum of the light degrees of freedom j = 0, 1 and with parity P = +, -. We present a preliminary extrapolation in the light u/d and an interpolation in the heavy b quark mass to the physical point and compare with available experimental results.
description: 7 pages, 2 figures, talk given at the XXVIII International Symposium on Lattice Field Theory (Lattice 2010), June 14-19 2010, Villasimius, Italy
Curvature weighted metrics on shape space of hypersurfaces in $n$-space
Creators: name: Bauer, Martin
name: Harms, Philipp
name: Michor, Peter W.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 58B20, 58D15, 58E12

description: Let $M$ be a compact connected oriented $n-1$ dimensional manifold without boundary. In this work, shape space is the orbifold of unparametrized immersions from $M$ to $\mathbb R^n$. The results of \cite{Michor118}, where mean curvature weighted metrics were studied, suggest incorporating Gauß curvature weights in the definition of the metric. This leads us to study metrics on shape space that are induced by metrics on the space of immersions of the form $$ G_f(h,k) = \int_{M} Φ. \bar g(h, k) \vol(f^*\bar{g}).$$ Here $f \in \Imm(M,\R^n)$ is an immersion of $M$ into $\R^n$ and $h,k\in C^\infty(M,\mathbb R^n)$ are tangent vectors at $f$. $\bar g$ is the standard metric on $\mathbb R^n$, $f^*\bar g$ is the induced metric on $M$, $\vol(f^*\bar g)$ is the induced volume density and $Φ$ is a suitable smooth function depending on the mean curvature and Gauß curvature. For these metrics we compute the geodesic equations both on the space of immersions and on shape space and the conserved momenta arising from the obvious symmetries. Numerical experiments illustrate the behavior of these metrics.
description: 12 pages 3 figures
Magnetic Diffusion in Star Formation
Creators: name: Basu, Shantanu
name: Dapp, Wolf B.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Magnetic diffusion plays a vital role in star formation. We trace its influence from interstellar cloud scales down to star-disk scales. On both scales, we find that magnetic diffusion can be significantly enhanced by the buildup of strong gradients in magnetic field structure. Large scale nonlinear flows can create compressed cloud layers within which ambipolar diffusion occurs rapidly. However, in the flux-freezing limit that may be applicable to photoionized molecular cloud envelopes, supersonic motions can persist for long times if driven by an externally generated magnetic field that corresponds to a subcritical mass-to-flux ratio. In the case of protostellar accretion, rapid magnetic diffusion (through Ohmic dissipation with additional support from ambipolar diffusion) near the protostar causes dramatic magnetic flux loss. By doing so, it also allows the formation of a centrifugal disk, thereby avoiding the magnetic braking catastrophe.
description: 5 pages, 4 figures. Conference proceedings of IAU Symposium 270, Computational Star Formation (eds. Alves, Elmegreen, Girart, Trimble)
On the influence of radio extended structures on offsets between the optical and VLBI positions of sources in the ICRF2
Creators: name: Camargo, J. I. B.
name: Andrei, A. H.
name: Assafin, M.
name: Vieira-Martins, R.
name: Neto, D. N. da Silva
Publisher: name: arXiv
Year: 2011
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Context: To investigate the differences between positions, as determined by optical (direct imaging) and Very Long Baseline Interferometry (VLBI) techniques, of extragalactic sources listed in the second realization of the International Celestial Reference Frame (ICRF2). Aims: To verify the influence of the source's intrinsic structure on these differences. Methods: Instruments with mosaics of CCDs were used to acquire the optical positions presented here, leading us to opt for overlapping techniques to build a virtual, continuous CCD over the whole angular size of the respective fields of view, whose translation of the resulting intrumental positions into positions that are consistent with those in the ICRF2 was made with the help of the UCAC2. Results: The differences obtained between the optical and VLBI positions of the observed sources may reach more than 80 milliarcseconds and, taking into consideration that they are hardly explained only by statistical fluctuations or systematic errors in the optical reference frame used here, we argue that these differences can be related to the sources' X-band structure index (8.4 GHz). Conclusions: In this context, the presence of the intrinsic structure should be taken into consideration when comparing the optical and VLBI positions of ICRF2 sources in the future.
description: Accepted on May 3rd 2011 by A&A
W/Z + jet production at the Tevatron
Creators: name: Sonnenschein, Lars
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Vector boson plus jet production is interesting for Higgs search, beyond the Standard Model physics and provides standard candles for calibration. This is complementary to inclusive jet production measurements which provide precision tests of perturbative QCD. A multitude of W/Z plus heavy and light flavour jet measurements in ppbar collisions at a centre of mass energy of sqrt{s}=1.96TeV is discussed. Next-to-Leading order perturbative QCD predictions and various models are compared to the measurements.
description: 4 pages, 1 figure
Remediating the First World War : literary and visual constructions of English-Canadian cultural memory
Creators: name: Fahey, Alicia
Publisher: name: University of British Columbia
Year: 2018

description: “Great nations write their autobiographies in three manuscripts – the book of their deeds, the book of their words and the book of their art.” When Paul Konody, art advisor for the Canadian War Memorials Fund (CWMF) First World War artist program, began his introductory essay to the exhibition catalogue Art & War (1919) with these words, he was making connections among the disciplines of history (deeds), literature (words), and (visual) art. Konody’s interdisciplinary understanding of representational media provides an appropriate point of entry for this dissertation, which investigates the intersectionalities of English-Canadian First World War art and literature. Building on a theoretical framework rooted in the concept and practice of remediation which, briefly, denotes a material reconfiguration of the original art object when it is later invoked in a literary work, I argue that the revival of Canadian military sculpture and paintings in contemporary First World War literature is evidence of a re-working of cultural memory of the Great War that continues to gain momentum in the immediate present and is indicative of a burgeoning, third phase of the memory boom in which media occupy a central position. Although some of the literary texts I examine apply remediation in its traditional sense, which functions to stabilize the original representation that it invokes, the focus of my study is on reversing this process by examining the ways in which English-Canadian authors have utilized remediation to reconsider official versions of the past through a revisionist lens. I conclude that, at its most effective, remediation operates as an act of intervention by deconstructing the state-sanctioned heroic sacrifice masternarrative that Canada came of age in the Great War and focusing instead on counternarratives that represent the diversity of the war experience. Indeed, my study offers proof that rethinking remediation in terms of deconstruction can reveal the supplementary nature of memory, precisely that the repeated invocation of a particular work of art may be indicative, not of the stability of memory, but of an anxiety about the limitations of memory and representation.
Calculating Kaon Fragmentation Functions from NJL-Jet Model
Creators: name: Matevosyan, Hrayr H.
name: Thomas, Anthony W.
name: Bentz, Wolfgang
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The Nambu--Jona-Lasinio (NJL) - Jet model provides a sound framework for calculating the fragmentation functions in an effective chiral quark theory, where the momentum and isospin sum rules are satisfied without the introduction of ad hoc parameters. Earlier studies of the pion fragmentation functions using the NJL model within this framework showed qualitative agreement with the empirical parameterizations. Here we extend the NJL-Jet model by including the strange quark. The corrections to the pion fragmentation functions and corresponding kaon fragmentation functions are calculated using the elementary quark to quark-meson fragmentation functions from NJL. The results for the kaon fragmentation functions exhibit a qualitative agreement with the empirical parameterizations, while the unfavored strange quark fragmentation to pions is shown to be of the same order of magnitude as the unfavored light quark's. The results of these studies are expected to provide important guidance for the analysis of a large variety of semi-inclusive data.
description: 9 pages, 14 figures
Quark-Gluon Plasma at RHIC and the LHC: Perfect Fluid too Perfect?
Creators: name: Nagle, James L.
name: Bearden, Ian G.
name: Zajc, William A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Relativistic heavy ion collisions have reached energies that enable the creation of a novel state of matter termed the quark-gluon plasma. Many observables point to a picture of the medium as rapidly equilibrating and expanding as a nearly inviscid fluid. In this article, we explore the evolution of experimental flow observables as a function of collision energy and attempt to reconcile the observed similarities across a broad energy regime in terms of the initial conditions and viscous hydrodynamics. If the initial spatial anisotropies are very similar for all collision energies from 39 GeV to 2.76 TeV, we find that viscous hydrodynamics might be consistent with the level of agreement for v2 of unidentified hadrons as a function of pT . However, we predict a strong collision energy dependence for the proton v2(pT). The results presented in this paper highlight the need for more systematic studies and a re-evaluation of previously stated sensitivities to the early time dynamics and properties of the medium.
description: 11 pages, 9 figures, submitted to the New Journal of Physics focus issue "Strongly Correlated Quantum Fluids: From Ultracold Quantum Gases to QCD Plasmas"
Commensurate Composite Fermions in Weak Periodic Electrostatic Potentials: Direct Evidence of a Periodic Effective Magnetic Field
Creators: name: Smet, J. H.
name: Jobst, S.
name: Klitzing, Klaus von
name: Weiss, Dieter
name: Wegscheider, Werner
name: Umansky, V.
Publisher: name: Universität Regensburg
Year: 1999
Subjects: subject: 530 Physik
subject: 73.40.Hm, 71.10.Pm, 73.50.Jt

description: Within the composite fermion model, it is anticipated that a periodic variation of the density in a two-dimensional electron system at half filling produces a periodic fictitious magnetic field. In regions of smaller density fictitious flux quanta are missing to compensate the external magnetic field. The observation of magnetic commensurability minima in the dc-transport response furnishes evidence for this fundamental aspect of the composite fermion picture. In general, composite fermions in these modulated systems behave largely equivalent to electrons moving in a periodic magnetic field.
IoT Relation and Impact on 5G
Creators: name: Davies, John
Publisher: name: Zenodo
Year: 2018

description: This report highlights several IoT vertical domain use cases collected by AIOTI (Alliance for IoT Innovation) and determines the specific requirements they impose on the underlying network infrastructure. These use cases and requirements can be used by SDOs (Standards Developing Organizations), such as 3GPP (3rd Generation Partnership Project) as requirements for automation in vertical domains focusing on critical communications.
description: This work is part of the NRG-5 project which has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 762013.othr
Dissecting the cosmic infra-red background with Herschel/PEP
Creators: name: Berta, S.
name: Magnelli, B.
name: Lutz, D.
name: Altieri, B.
name: Aussel, H.
name: Andreani, P.
name: Bauer, O.
name: Bongiovanni, A.
name: Cava, A.
name: Cepa, J.
name: Cimatti, A.
name: Daddi, E.
name: Dominguez, H.
name: Elbaz, D.
name: Feuchtgruber, H.
name: Schreiber, N. M. Foerster
name: Genzel, R.
name: Gruppioni, C.
name: Katterloher, R.
name: Magdis, G.
name: Maiolino, R.
name: Nordon, R.
name: Garcia, A. M. Perez
name: Poglitsch, A.
name: Popesso, P.
name: Pozzi, F.
name: Riguccini, L.
name: Rodighiero, G.
name: Saintonge, A.
name: Santini, P.
name: Sanchez-Portal, M.
name: Shao, L.
name: Sturm, E.
name: Tacconi, L. J.
name: Valtchanov, I.
name: Wetzstein, M.
name: Wieprecht, E.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The constituents of the cosmic IR background (CIB) are studied at its peak wavelengths (100 and 160 um) by exploiting Herschel/PACS observations of the GOODS-N, Lockman Hole, and COSMOS fields in the PACS Evolutionary Probe (PEP) guaranteed-time survey. The GOODS-N data reach 3 sigma depths of ~3.0 mJy at 100 um and ~5.7 mJy at 160 um. At these levels, source densities are 40 and 18 beams/source, respectively, thus hitting the confusion limit at 160 um. Differential number counts extend from a few mJy up to 100-200 mJy, and are approximated as a double power law, with the break lying between 5 and 10 mJy. The available ancillary information allows us to split number counts into redshift bins. At z<=0.5 we isolate a class of luminous sources (L(IR)~1e11 Lsun), whose SEDs resemble late-spiral galaxies, peaking at ~130 um restframe and significantly colder than what is expected on the basis of pre-Herschel models. By integrating number counts over the whole covered flux range, we obtain a surface brightness of 6.36 +/- 1.67 and 6.58 +/-1.62 [nW m^-2 sr^-1] at 100 and 160 um, resolving ~45% and ~52% of the CIB, respectively. When stacking 24 um sources, the inferred CIB lies within 1.1 sigma and 0.5 sigma from direct measurements in the two bands, and fractions increase to 50% and 75%.Most of this resolved CIB fraction was radiated at z<=1.0, with 160 um sources found at higher redshift than 100 um ones.
description: Accepted for publication on the A&A Herschel Special Issue
Classification of normal sequences
Creators: name: Djokovic, Dragomir Z.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05B20:05B30

description: Base sequences BS(m,n) are quadruples (A;B;C;D) of {+1,-1}-sequences, with A and B of length m and C and D of length n, such that the sum of their nonperiodic autocorrelation functions is a delta-function. Normal sequences NS(n) are base sequences (A;B;C;D) in BS(n,n) such that A=B. We introduce a definition of equivalence for normal sequences NS(n), and construct a canonical form. By using this canonical form, we have enumerated the equivalence classes of NS(n) for n <= 40.
description: 18 pages
Multi-wavelength Observations of the Flaring Gamma-ray Blazar 3C 66A in 2008 October
Creators: name: LAT Collaboration
name: al., A. A. Abdo et
name: collaboration, the VERITAS
name: :
name: al., V. A. Acciari et
name: consortium, the GASP-WEBT
name: partners, multi-wavelength
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The BL Lacertae object 3C 66A was detected in a flaring state by the Fermi Large Area Telescope (LAT) and VERITAS in 2008 October. In addition to these gamma-ray observations, F-GAMMA, GASP-WEBT, PAIRITEL, MDM, ATOM, Swift, and Chandra provided radio to X-ray coverage. The available light curves show variability and, in particular, correlated flares are observed in the optical and Fermi-LAT gamma-ray band. The resulting spectral energy distribution can be well fit using standard leptonic models with and without an external radiation field for inverse-Compton scattering. It is found, however, that only the model with an external radiation field can accommodate the intra-night variability observed at optical wavelengths.
description: Accepted for publication in ApJ. 32 pages, 8 figures and 5 tables. Corresponding author: Luis C. Reyes (lcreyes@uchicago.edu)
A Study of IEEE 802.15.4 Security Framework for Wireless Body Area Network
Creators: name: Saleem, Shahnaz
name: Ullah, Sana
name: Kwak, Kyung Sup
Publisher: name: arXiv
Year: 2011
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: A Wireless Body Area Network (WBAN) is a collection of low-power and lightweight wireless sensor nodes that are used to monitor the human body functions and the surrounding environment. It supports a number of innovative and interesting applications, including ubiquitous healthcare and Consumer Electronics (CE) applications. Since WBAN nodes are used to collect sensitive (life-critical) information and may operate in hostile environments, they require strict security mechanisms to prevent malicious interaction with the system. In this paper, we first highlight major security requirements and Denial of Service (DoS) attacks in WBAN at Physical, Medium Access Control (MAC), Network, and Transport layers. Then we discuss the IEEE 802.15.4 security framework and identify the security vulnerabilities and major attacks in the context of WBAN. Different types of attacks on the Contention Access Period (CAP) and Contention Free Period (CFP) parts of the superframe are analyzed and discussed. It is observed that a smart attacker can successfully corrupt an increasing number of GTS slots in the CFP period and can considerably affect the Quality of Service (QoS) in WBAN (since most of the data is carried in CFP period). As we increase the number of smart attackers the corrupted GTS slots are eventually increased, which prevents the legitimate nodes to utilize the bandwidth efficiently. This means that the direct adaptation of IEEE 802.15.4 security framework for WBAN is not totally secure for certain WBAN applications. New solutions are required to integrate high level security in WBAN.
description: 14 pages, 7 figures, 2 tables
Massive black hole binary eccentricity in rotating stellar systems
Creators: name: Sesana, Alberto
name: Gualandris, Alessia
name: Dotti, Massimo
Publisher: name: arXiv
Year: 2011
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In this letter we study the eccentricity evolution of a massive black hole (MBH) binary (MBHB) embedded in a rotating stellar cusp. Following the observation that stars on counter-rotating (with respect to the MBHB) orbits extract angular momentum from the binary more efficiently then their co-rotating counterparts, the eccentricity evolution of the MBHB must depend on the degree of co-rotation (counter-rotation) of the surrounding stellar distribution. Using an hybrid scheme that couples numerical three-body scatterings to an analytical formalism for the cusp-binary interaction, we verify this hypothesis by evolving the MBHB in spherically symmetric cusps with different fractions F of co-rotating stars. Consistently with previous works, binaries in isotropic cusps (F=0.5) tend to increase their eccentricity, and when F approaches zero (counter-rotating cusps) the eccentricity rapidly increases to almost unity. Conversely, binaries in cusps with a significant degree of co-rotation (F>0.7) tend to become less and less eccentric, circularising quite quickly for F approaching unity. Direct N-body integrations performed to test the theory, corroborate the results of the hybrid scheme, at least at a qualitative level. We discuss quantitative differences, ascribing their origin to the oversimplified nature of the hybrid approach.
description: 6 pages, 2 figures, accepted for publication in MNRAS
Application of arbuscular mycorrhizal fungi and potassium nitrate improves physiological performance and glycyrrhizin production of licorice under salt stress
Creators: name: Davar, Rozita
name: Sabbaghtazeh, Elnaz
name: Bybordi, Ahmad
name: Dalalian, Mohammad Reza
name: Saedi, Siamak
Publisher: name: Journal of Applied Botany and Food Quality
Year: 2023

description: To examine the effects of potassium nitrate fertilizer (40 and 80 kg ha-1) and inoculation with arbuscular mycorrhizal fungi (25, 50, and 100 g inoculum) on the physiological performance and glycyrrhizin production of licorice plants (Glycyrrhiza glabra L.) under salt stress (irrigation with 4 and 8 dSm-1 of saline water), two field experiments were conducted in 2021 and 2022. Salinity reduced the physiological performance of plants but increased the concentration of glycyrrhizin in the roots. The application of potassium nitrate, especially at a rate of 40 kg ha-1, along with mycorrhiza, resulted in increased nutrient content, antioxidative activities (catalase, peroxidase, and superoxide dismutase activities), membrane stability index, leaf relative water content, photosynthetic pigment content, glycyrrhizin production, and growth (about 45%) of licorice plants. On the other hand, the treatment with KNO3 and mycorrhiza reduced the accumulation of sodium in plant tissues (about 16%). The application of 40 kg ha-1 KNO3 with 50 g of inoculum was found to be the superior treatment for improving the performance of licorice plants under salt stress. According to the findings of this study, the use of KNO3 in combination with arbuscular mycorrhizal fungi is a successful approach to improve plant growth and productivity under saline conditions.
description: Journal of Applied Botany and Food Quality, Vol. 96 (2023): Journal of Applied Botany and Food Quality
Interaction between selenium and sulfur promotes alteration in the internal quality traits in green and red lettuce
Creators: name: Abdalla, Muna Ali
name: Nisa, Fatiha Kalam
name: Mühling, Karl Hermann
Publisher: name: Journal of Applied Botany and Food Quality
Year: 2023

description: The interaction between selenium (Se) and sulfur (S) was investigated in green and red lettuce grown in a hydroponic system contain-
ing a basal mineral complement at contrasting levels of Se and S. The experiment aimed to evaluate the impact of Se and S supplementation on the quality traits of the lettuce, including soluble sugars, organic acids, total protein and nitrate (NO3−) to result in better lettuce yield with improving quality. The Se and S concentrations determined in the lettuce leaves showed complex dependence on the various levels of selenate (SeO42−) and sulfate (SO42−) supplied via the foliar application and the nutrient solution, respectively.

The foliar application of Se resulted in a synergistic interaction between both elements. With elevated Se and S (Se2/S2), Se accumulation was enhanced drastically in red lettuce, and in green lettuce, the S concentration increased significantly. Regarding carbohydrate accumulation, including water-soluble sugars, a lower Se dose under adequate S conditions enhanced glucose levels significantly by 3.2 and 2.1-fold in green and red lettuce, respectively. A synergistic interaction between Se and S was found following higher Se and S treatment (Se2/S2), resulting in a significant (p ≤ 0.05) reduction in glucose and fructose concentrations. However, higher S strikingly increased the accumulation of the reducing sugars (glucose and fructose) by 5.3 and 3.0-fold for glucose and 3.7 and 5.6-fold for fructose in green and red lettuce, respectively. Meanwhile, sucrose increased by 2.0-fold in red lettuce and remained unaltered in green lettuce. A low nitrate level (NO3−) was maintained in response to adequate or elevated S and Se levels. Se levels (Se1 and Se2) did not affect total protein concentration under contrasting sulfate/selenate. However, potential effects in terms of protein accumulation were associated with an adequate or increased S concentration. The data suggest that lower Se and sufficient S doses significantly increase glucose levels in both pigmented lettuce cultivars. Additionally, the synergistic interaction between Se and S could benefit the final nutritional value and quality of lettuce, especially for nitrate, where Se and S enrichment can ensure low nitrate levels.
description: Journal of Applied Botany and Food Quality, Vol. 96 (2023): Journal of Applied Botany and Food Quality
Unitarity bounds on low scale quantum gravity
Creators: name: Atkins, Michael
name: Calmet, Xavier
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the unitarity of models with low scale quantum gravity both in four dimensions and in models with a large extra-dimensional volume. We find that models with low scale quantum gravity have problems with unitarity below the scale at which gravity becomes strong. An important consequence of our work is that their first signal at the Large Hadron Collider would not be of a gravitational nature such as graviton emission or small black holes, but rather linked to the mechanism which fixes the unitarity problem. We also study models with scalar fields with non minimal couplings to the Ricci scalar. We consider the strength of gravity in these models and study the consequences for inflation models with non-minimally coupled scalar fields. We show that a single scalar field with a large non-minimal coupling can lower the Planck mass in the TeV region. In that model, it is possible to lower the scale at which gravity becomes strong down to 14 TeV without violating unitarity below that scale.
description: 15 pages