cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The rotator spectrum in the delta-regime of the O(n) effective field theory in 3 and 4 dimensions
Creators: name: Niedermayer, Ferenc
name: Weiermann, Christoph
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: The low lying spectrum of the O(n) effective field theory is calculated in the delta-regime in 3 and 4 space-time dimensions using lattice regularization to NNL order. It allows, in particular, to determine, using numerical simulations in different spatial volumes, the pion decay constant F in QCD with 2 flavours or the spin stiffness rho for an antiferromagnet in d=2+1 dimensions.
description: 20 pages, no figures
Looking for trouble : relations between the hostile attentional bias and aggression in boys
Creators: name: Miller, Natalie V.
Publisher: name: University of British Columbia
Year: 2016

description: The social information-processing model argues that preferentially attending to hostile cues (hostile attentional bias) predisposes children to behave aggressively. However, the attentional processes involved in this bias are not well specified and research following from the model has produced inconsistent results, suggesting a possible moderating variable. To address these issues, the current study examined the relation between a hostile attentional bias and aggression in a community sample of 113 boys (9-12 years). The hostile attentional bias was measured using three attention tasks (a dot-probe, a temporal order judgment, and an attention shifting task) designed to assess attentional biases within different attentional processes. Bias scores were calculated by comparing boys’ performance in response to hostile versus neutral stimuli (e.g., photos of angry versus neutral peer faces). Aggression was measured using parent- and child- reports, combined into a composite variable. Based on previous research of attentional biases within the anxiety literature, effortful control was identified as a possible moderating variable and was measured in the current study using parent-report. The findings from this study were mixed. In support of the hypotheses, bias scores computed from the temporal order judgment task were positively related to aggression. Effortful control moderated this relation, which was attenuated as levels of effortful control increased. Conversely, bias scores computed from the dot-probe and attention shifting tasks were not significantly related to aggression, and effortful control was not a significant moderator. Interestingly, in follow-up analyses using bias scores contrasting response to neutral versus happy stimuli in the attention shifting task, being distracting by neutral stimuli was positively related to aggression; this relation was moderated by effortful control. Post-task emotion ratings of these stimuli revealed that aggression was associated with a tendency to rate neutral stimuli as appearing angrier. Given these findings, the attentional salience of neutral stimuli is discussed. These results highlight the importance of considering multiple attentional processes in the measurement of attentional biases, and extend previous research by demonstrating a link between aggression and a hostile attentional bias within certain attentional processes. These results also suggest that effortful control may exert some protective effects against the bias.
Dorothy Vanderpool, 1943
Creators: name: Kelsey, Carleton
name: Kelsey, Carleton, 1913-2005
Publisher: name: Unknown
Year: 1943
Subjects: Photographs
People
Portraits
Women

description: This image shows Dorothy Vanderpool in 1943. She is staring at the camera while leaning on a table. This photograph was either taken or collected by Amagansett historian and librarian Carleton Kelsey.
description: This photograph is part of the collection of the Carleton Kelsey Collection of the Amagansett Historical Association. Kelsey was a local historian and librarian who collected photographs from others to add to the many photographs he took of the community himself.
Exploring ecojustice learning among youth
Creators: name: Parker, Rebekah
Publisher: name: University of British Columbia
Year: 2016

description: Ecojustice theory, as described by Martusewicz, Emundson, & Lupinacci (2011), consists of three threads: understanding the interdependence of local and global ecosystems, deep cultural analysis of Western thinking and in situ systems, and “need to restore the cultural and environmental commons” (p. 20). Working with youth (15-18 years) at the Pearson Seminar on Youth Leadership (PSYL), an environmental and social justice leadership program, this research project focuses on how youth respond to and share ecojustice learnings beyond the classroom setting, and how it might inform ecojustice pedagogy. Through journal reflections, Forum Theatre (Boal, 2002), and narrative inquiry, this thesis explores methods youth use for sharing their understandings of ecojustice with their families, friends and communities. Synthesis/analysis of data includes a “dataplay” (O’Riley, 2003) where participants’ “data” is presented as conversations in an interactive script and responded to by the participants. This changes the power relations between actor and observer as well as scripted and spontaneous intervention within the research process. The youth participants articulated a desire to overcome apathy among some of their peers, together with a need to develop strategies for having (at times) difficult conversations about social justice and ecological justice concerns around the world. They expressed feelings of guilt and fear, together with a strong desire to create change when addressing systemic global issues like climate change and out of control consumerism. Storytelling, other creative engagements with the issues being dealt with, and personal conversations were offered as possible pedagogic solutions. The students also explored the emotional effects of working with difficult issues. The youth’s responses call on PSYL educators to address ecojustice issues in their teaching, as well as possibilities for actions that the youth can implement in their local communities.
System Requirements Specification for BBCDMSS
Creators: name: BERINDA Nanyonga
Publisher: name: Zenodo
Year: 2018

description: The purpose for developing the Biometric Based Car to Driver Matching Security System, version 1.0, is to enhance the security of cars in parking areas by matching the driver to the number plate of his/her car hence reducing car thefts. The car driver’s biometric will be matched to his/her car on entry to the parking area and the same will be captured on exit to make sure that the first biometric of the driver on entry is the same as the one on exit. This will reduce on the number of cars that are stolen in parking areas. In case of a mismatch, the vehicle will not be allowed to leave the parking area and the person taking the car will be taken in for questioning as the driver who brought the car is contacted. The system will use some data from the national identity registration authority to ensure that security of the parking area users is very high. This will further reduce on the thefts since it will now be easy to track all the people who use the parking area using their data. This SRS describes the whole system.
Untersuchungen zur Integration der fluktuierenden Windenergie in das System der Elektroenergieversorgung
Creators: name: Pforte, René
Publisher: name: Karlsruhe
Year: 2010
Subjects: Windenergie
Ausgleichseffekt
Hybridkraftwerk
Elektroenergieversorgung
Integration

description: Die Arbeit systematisiert Herausforderungen und beschreibt Lösungsansätze zur Integration der fluktuierenden Windenergie in das System der Elektroenergieversorgung Europas. Dazu werden u.a. Optimierungsmodelle zur Standortauswahl von Windenergieanlagen und darauf aufbauend zur Quantifizierung des weiträumigen Ausgleichseffekts der Windenergie auf Basis meteorologischer Daten vorgestellt. Die Windenergie kann demnach einen maßgeblichen Beitrag zur Bereitstellung elektrischer Energie leisten.
A Quantitative Model for Drifting Subpulses in PSR B0809+74
Creators: name: Rosen, R.
name: Demorest, P.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In this paper we analyze high time resolution single pulse data of PSR B0809+74 at 820 MHz. We compare the subpulse phase behavior, undocumented at 820 MHz, with previously published results. The subpulse period changes over time and we measure a subpulse phase jump, when visible, that ranges from 95 to 147 degrees. We find a correlation between the subpulse modulation, subpulse phase, and orthogonal polarization modes. This variety of complicated behavior is not well understood and is not easily explained within the framework of existing models, most of which are founded on the drifting spark model of Ruderman & Sutherland (1975). We quantitatively fit our data with a non-radial oscillation model (Clemens & Rosen 2008) and show that the model can accurately reproduce the drifting subpulses, orthogonal polarization modes, subpulse phase jump, and can explain the correlation between all these features.
description: 33 pages, 13 figures, 3 tables, Accepted for publication in ApJ
Optimization and characterization of microbial rhamnolipid production from renewable resources
Creators: name: Müller, Markus Michael
Publisher: name: Karlsruhe
Year: 2011
Subjects: Biosurfactants
Rhamnolipids
Systems Biotechnology
Renewable Resources
Nachwachsende Rohstoffe

description: The thesis at hand is based on a compendium of peer-reviewed works that were independently published during the last three years. These publications compose of one general introducing book chapter, two original papers which reflect a part of the laboratory work, and a review article that is concluding the last years of rhamnolipid research and gives an outlook of the possible and necessary works for the future.
Numerical simulations of compressible Rayleigh-Taylor turbulence in stratified fluids
Creators: name: Scagliarini, A.
name: Biferale, L.
name: Sbragaglia, M.
name: Sugiyama, K.
name: Toschi, F.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We present results from numerical simulations of Rayleigh-Taylor turbulence, performed using a recently proposed lattice Boltzmann method able to describe consistently a thermal compressible flow subject to an external forcing. The method allowed us to study the system both in the nearly-Boussinesq and strongly compressible regimes. Moreover, we show that when the stratification is important, the presence of the adiabatic gradient causes the arrest of the mixing process.
description: 15 pages, 11 figures. Proceedings of II Conference on Turbulent Mixing and Beyond (TMB-2009)
The spectroscopic evolution of the symbiotic-like recurrent nova V407 Cygni during its 2010 outburst. I. The shock and its evolution
Creators: name: Shore, S. N.
name: Wahlgren, G. M.
name: Augusteijn, T.
name: Liimets, T.
name: Page, K. L.
name: Osborne, J. P.
name: Beardmore, A. P.
name: Koubsky, P.
name: Šlechta, M.
name: Votruba, V.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: On 2010 Mar 10, V407 Cyg was discovered in outburst, eventually reaching V< 8 and detected by Fermi. Using medium and high resolution ground-based optical spectra, visual and Swift UV photometry, and Swift X-ray spectrophotometry, we describe the behavior of the high-velocity profile evolution for this nova during its first three months. The peak of the X-ray emission occurred at about day 40 with a broad maximum and decline after day 50. The main changes in the optical spectrum began at around that time. The He II 4686A line first appeared between days 7 and 14 and initially displayed a broad, symmetric profile that is characteristic of all species before day 60. Low-excitation lines remained comparatively narrow, with v(rad,max) of order 200-400 km/s. They were systematically more symmetric than lines such as [Ca V], [Fe VII], [Fe X], and He II, all of which showed a sequence of profile changes going from symmetric to a blue wing similar to that of the low ionization species but with a red wing extended to as high as 600 km/s . The Na I D doublet developed a broad component with similar velocity width to the other low-ionization species. The O VI Raman features were not detected. We interpret these variations as aspherical expansion of the ejecta within the Mira wind. The blue side is from the shock penetrating into the wind while the red wing is from the low-density periphery. The maximum radial velocities obey power laws, v(rad,max) t^{-n} with n ~ 1/3 for red wing and ~0.8 for the blue. (truncated)
description: Accepted for publication, A&A (submitted: 9 Oct 2010; accepted: 1 Dec 2010) in press; based on data obtained with Swift, Nordic Optical Telescope, Ondrejov Observatory. Corrected typo, Fermi?LAT detection was at energies above 100 MeV (with thanks to C. C. Cheung)
CLKscrew: Exposing the Perils of Security-Oblivious Energy Management, Usenix 2018 (Distinguished Paper Award)
Creators: name: Tang, Adrian
name: Sethumadhavan, Simha
name: Stolfo, Salvatore
Publisher: name: Columbia University
Year: 2018
Subjects: Computer science
Computer networks
Computer security
Energy consumption

description: The need for power- and energy-efficient computing has resulted in aggressive cooperative hardware-software en- ergy management mechanisms on modern commodity devices. Most systems today, for example, allow soft- ware to control the frequency and voltage of the under- lying hardware at a very fine granularity to extend bat- tery life. Despite their benefits, these software-exposed energy management mechanisms pose grave security im- plications that have not been studied before.
In this work, we present the CLKSCREW attack, a new class of fault attacks that exploit the security- obliviousness of energy management mechanisms to break security. A novel benefit for the attackers is that these fault attacks become more accessible since they can now be conducted without the need for physical access to the devices or fault injection equipment. We demonstrate CLKSCREW on commodity ARM/Android devices. We show that a malicious kernel driver (1) can extract secret cryptographic keys from Trustzone, and (2) can escalate its privileges by loading self-signed code into Trustzone. As the first work to show the security ramifications of energy management mechanisms, we urge the community to re-examine these security-oblivious designs.
Die Magnetfeldüberlagerte Zentrifugation : 
Ein neues hybrides Trennverfahren zur Selektiven
Bioseparation
Creators: name: Stolarski, Mathias
Publisher: name: Karlsruhe
Year: 2011
Subjects: Magnetseparation
Zentrifugation
Bioseparation
Magnetzentrifugation

description: Die Magnetfeldüberlagerte Zentrifugation ist ein neues hybrides Trennverfahren zur Abtrennung von Bioprodukten. Dabei kommen funktionalisierte magnetische Trägerpartikel zum Einsatz. Diese binden das Zielprodukt an ihrer Oberflächen und werden dann aufgrund ihrer magnetischen Eigenschaften mit dem neuen Verfahren abgetrennt. Die Arbeit fasst die wesentlichen Versuchsergebnisse aus Experimenten und Simulation zusammen.
Simulation of haemodynamic flow in head and neck chemotherapy
Creators: name: Rhode, S.
Publisher: name: Karlsruhe
Year: 2011

description: In recent years, intra arterial chemotherapy has become an important component in head and neck cancer treatment. However, therapy success can vary significantly and consistent treatment guidelines are missing.

The purpose of this study was to create a computer simulation of the chemical agent injection in the head and neck arteries to investigate the distribution and concentration of the chemical. This is of great interest for medical scientists and vital for prognosis. Realistic three dimensional patient specific geometry was created from image scan data. Engineering principles such as conservation of mass and momentum, turbulence models and a multiphase model were applied in a computational fluid dynamics (CFD) software.

At first, a steady cause and effect study with various turbulence and material models was made without the chemical component. It was discovered, that a non-\Newtonian material model is compulsory for blood. The shear stress transport k-w turbulence model is appropriate for the whole velocity range and of superior robustness.

These conclusions were used in the following two-component transient simulation. Pulsatile blood flow, turbulence, the chemical agent injection via a catheter and the mixture between blood and the chemical were considered. The principal conclusion was; the modelled catheter position right before the common carotid artery bifurcation produced an ineffective cisplatin distribution consistent throughout all the arteries. Due to high wall shear stress and turbulence at the inner bifurcation wall, serious complications during the treatment could occur, for instance heamolysis or acute vascular endothelial changes.

To the best of the author's knowledge a novel \CFD based approach was introduced, suitable for the optimization and the formulation of treatment guidelines in intra arterial injection chemotherapy. After a required validation, this model can be modified to investigate the influence of various catheter positions and dose rate schemes in future simulations.
Quantum effects in energy and charge transfer in an artificial photosynthetic complex
Creators: name: Ghosh, Pulak Kumar
name: Smirnov, Anatoly Yu.
name: Nori, Franco
Publisher: name: arXiv
Year: 2011
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the quantum dynamics of energy and charge transfer in a wheel-shaped artificial photosynthetic antenna-reaction center complex.This complex consists of six light-harvesting chromophores and an electron-acceptor fullerene. To describe quantum effects on a femtosecond time scale, we derive the set of exact non-Markovian equations for the Heisenberg operators of this photosynthetic complex in contact with a Gaussian heat bath. With these equations we can analyze the regime of strong system-bath interactions, where reorganization energies are of the order of the intersite exciton couplings. We show that the energy of the initially-excited antenna chromophores is efficiently funneled to the porphyrin-fullerene reaction center, where a charge-separated state is set up in a few picoseconds, with a quantum yield of the order of 95%. In the single-exciton regime, with one antenna chromophore being initially excited, we observe quantum beatings of energy between two resonant antenna chromophores with a decoherence time of $\sim$ 100 fs. We also analyze the double-exciton regime, when two porphyrin molecules involved in the reaction center are initially excited. In this regime we obtain pronounced quantum oscillations of the charge on the fullerene molecule with a decoherence time of about 20 fs (at liquid nitrogen temperatures). These results show a way to directly detect quantum effects in artificial photosynthetic systems.
High-yield production of graphene sheets by graphite electro-exfoliation for application in electrochemical power sources
Creators: name: Taheri Najafabadi, Amin
Publisher: name: University of British Columbia
Year: 2016

description: This thesis first aims at developing an electrochemical approach for low temperature, simple, and cost-effective synthesis of graphene microsheets (GNs) using graphitic electrodes in ionic liquid (IL) medium. The second major focus involves the products application as cathode-modifying microporous layers (MPLs) in proton exchange membrane fuel cells (PEMFCs) as well as anode-modifying materials in microbial fuel cells (MFCs). For the electrochemical exfoliation, a novel IL/acetonitrile electrolyte is introduced, and investigated with low concentration of ionic liquids. Using iso-molded graphite rod as the anode, up to 86% of exfoliation was achieved with the majority of the products as graphene flakes in addition to smaller quantities of carbonaceous particles and rolled sheets. Moreover, the simultaneous anodic and cathodic GN production was developed here with a synergistic exfoliation effect. When graphitic anode and cathode were subjected to a constant cell potential, up to 3 times higher exfoliation yields were generated compared to single-electrode studies on each side (~6-fold improvement in total). Thorough materials characterization confirmed the production of ultrathin GNs (< 5 layers) on both electrodes, with cathodic sheets being relatively larger and less functionalized. On the application side, the successful integration of GNs in MPLs resulted in enhanced PEMFC performance over a wide range of operating conditions. GN-based MPLs improved performance in the kinetic and ohmic regions of the polarization curve, while the addition of carbon black (CB), particularly Vulcan XC72, to form a composite GN+CB MPL, further extended the improvement to the mass transport limiting region. This was reflected by an approximate 30% and 70% increase in peak power densities compared to CB and GN MPLs, respectively, at the relative humidity (RH) of 100%. Despite the presence of CB, GN+CB MPLs also retained their superior performance at a much lower RH of 20%, thereby widening the peak power gap with CB MPLs to 80%. On the other side, the functionalized GN-modified carbon cloth anodes integrated within single-chamber MFCs generated an over four-fold improvement in peak power density compared to the plain carbon cloth (2.85 W m-² vs 0.66 W m-², respectively), exceeding the previously reported values with graphene anodes.
Fermi Large Area Telescope View of the Core of the Radio Galaxy Centaurus A
Creators: name: Fermi Collaboration
name: Falcone, A.
name: Hase, H.
name: Pagoni, C.
name: Ploetz, C.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present gamma-ray observations with the LAT on board the Fermi Gamma-Ray Telescope of the nearby radio galaxy Centaurus~A. The previous EGRET detection is confirmed, and the localization is improved using data from the first 10 months of Fermi science operation. In previous work, we presented the detection of the lobes by the LAT; in this work, we concentrate on the gamma-ray core of Cen~A. Flux levels as seen by the LAT are not significantly different from that found by EGRET, nor is the extremely soft LAT spectrum ($\G=2.67\pm0.10_{stat}\pm0.08_{sys}$ where the photon flux is $Φ\propto E^{-\G}$). The LAT core spectrum, extrapolated to higher energies, is marginally consistent with the non-simultaneous HESS spectrum of the source. The LAT observations are complemented by simultaneous observations from Suzaku, the Swift Burst Alert Telescope and X-ray Telescope, and radio observations with the Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry (TANAMI) program, along with a variety of non-simultaneous archival data from a variety of instruments and wavelengths to produce a spectral energy distribution (SED). We fit this broadband data set with a single-zone synchrotron/synchrotron self-Compton model, which describes the radio through GeV emission well, but fails to account for the non-simultaneous higher energy TeV emission observed by HESS from 2004-2008. The fit requires a low Doppler factor, in contrast to BL Lacs which generally require larger values to fit their broadband SEDs. This indicates the $\g$-ray emission originates from a slower region than that from BL Lacs, consistent with previous modeling results from Cen~A. This slower region could be a slower moving layer around a fast spine, or a slower region farther out from the black hole in a decelerating flow.
description: Accepted by ApJ. 32 pages, 5 figures, 2 tables. J. Finke and Y. Fukazawa corresponding authors
Comment on the uncertainty relation with periodic boundary conditions
Creators: name: Fujikawa, Kazuo
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The Kennard-type uncertainty relation $ΔxΔp >\frac{\hbar}{2}$ is formulated for a free particle with given momentum < \hat{p}>$ inside a box with periodic boundary conditions in the large box limit. Our construction of a free particle state is analogous to that of the Bloch wave in a periodic potential. A simple Robertson-type relation, which minimizes the effect of the box boundary and may be useful in some practical applications, is also presented.
description: 17 pages, to appear in Prog. Theor. Phys. (kyoto)
Fourier mode dynamics for the nonlinear Schroedinger equation in one-dimensional bounded domains
Creators: name: Caputo, J. G.
name: Efremidis, N. K.
name: Hang, Chao
Publisher: name: arXiv
Year: 2011
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We analyze the 1D focusing nonlinear Schrödinger equation in a finite interval with homogeneous Dirichlet or Neumann boundary conditions. There are two main dynamics, the collapse which is very fast and a slow cascade of Fourier modes. For the cubic nonlinearity the calculations show no long term energy exchange between Fourier modes as opposed to higher nonlinearities. This slow dynamics is explained by fairly simple amplitude equations for the resonant Fourier modes. Their solutions are well behaved so filtering high frequencies prevents collapse. Finally these equations elucidate the unique role of the zero mode for the Neumann boundary conditions.
Associated production of one particle and a Drell-Yan pair
Creators: name: Ceccopieri, Federico Alberto
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We briefly discuss the collinear factorization formula for the associated production of one particle and a Drell-Yan pair in hadronic collisions. We outline possible applications of the results to three different research areas.
description: Contributed to 15th International QCD Conference: QCD 10 (25th anniversary), Montpellier, France, 28 Jun - 3 Jul 2010
UAV-based remote sensing of fluvial hydrogeomorphology and aquatic habitat dynamics
Creators: name: Tamminga, Aaron
Publisher: name: University of British Columbia
Year: 2016

description: Recent advances in methodological and theoretical approaches in fluvial sciences have given rise to increased interest in riverscape perspectives that embrace environmental variability and spatial relationships. These approaches facilitate interdisciplinary understanding of complex fluvial processes that supports conscientious management of river systems. In this context, this dissertation presents the development and application of novel methods to study fluvial structure and eco-hydrogeomorphic relationships. Specifically, the research addresses three main questions: (1) how can UAV-based remote sensing advance the study of fluvial forms and processes? (2) what are the reach-scale geomorphic effects of an extreme flood and to what extent are these changes predictable? and (3) what are the linkages between flood-induced geomorphic change, reach hydraulics, and aquatic habitat? Results based on the case of an extreme flood event on Elbow River, Alberta demonstrate the utility of UAVs to efficiently and accurately measure many aspects of fluvial ecosystem form and function. The combination of high resolution imagery and photogrammetrically derived elevation models provides a powerful way to characterize rivers for a wide range of applications, particularly when combined with numerical flow modeling for a seamless representation of fluvial hydrogeomorphology. Pre- and post-flood UAV surveys documented flood effects with unprecedented detail, showing a largely unpredictable fluvial response characterized by complete channel planform reorganization and widespread bank erosion. These geomorphic changes negatively impacted the study reach in terms of hydraulic diversity and habitat suitability for brown trout and constrain future fluvial adjustment during smaller floods. Overall, the dissertation presents a new way to measure rivers and extract meaningful information and provides an integrative assessment of relationships between geomorphology, hydraulics, and aquatic ecology in a complex, dynamic river system.
Anomalous enhancement of spin Hall conductivity in superconductor/normal metal junction
Creators: name: Hikino, S.
name: Yunoki, S.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We propose a spin Hall device to induce a large spin Hall effect in a superconductor/normal metal (SN) junction. The side jump and skew scattering mechanisms are both taken into account to calculate the extrinsic spin Hall conductivity in the normal metal. We find that both contributions are anomalously enhanced when the voltage between the superconductor and the normal metal approaches to the superconducting gap. This enhancement is attributed to the resonant increase of the density of states in the normal metal at the Fermi level. Our results demonstrate a novel way to control and amplify the spin Hall conductivity by applying an external dc electric field, suggesting that a SN junction has a potential application for a spintronic device with a large spin Hall effect.
description: 5 pages, 4 figures, To be published as a Rapid Communication in Physical Review B
Emergent structure in a dipolar Bose gas in a one-dimensional lattice
Creators: name: Wilson, Ryan M.
name: Bohn, John L.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We consider an ultracold dipolar Bose gas in a one-dimensional lattice. For a sufficiently large lattice recoil energy, such a system becomes a series of non-overlapping Bose-Einstein condensates that interact via the long-range dipole-dipole interaction (ddi). We model this system via a coupled set of non-local Gross-Pitaevskii equations (GPEs) for lattices of both infinite and finite extent. We find significantly modified stability properties in the lattice due to the softening of a discrete roton-like mode, as well as "islands" in parameter space where biconcave densities are predicted to exist that only exist in the presence of the other condensates on the lattice. We solve for the elementary excitations of the system to check the dynamical stability of these solutions and to uncover the nature of their collapse. By solving a coupled set of GPEs exactly on a full numeric grid, we show that this emergent biconcave structure can be realized in a finite lattice with atomic $^{52}$Cr.
description: 7+ pages, 2 column format, 7 figures
Characterizing the link between fire history, productivity, and forest structure across Canada’s northern boreal using multi-source remote sensing
Creators: name: Bolton, Douglas Kane
Publisher: name: University of British Columbia
Year: 2016

description: Forest structure is an important indicator of ecosystem function and carbon storage in above-ground biomass, yet observations of forest structure are scarce across Canada’s unmanaged bo-real. To reduce uncertainties in global carbon budgets, an improved understanding of spatial and temporal variability in forest structure is required across unmanaged boreal forests. The objective of this dissertation is to investigate how fire history and forest productivity together shape the structure of Canada’s boreal forests, and to develop methods to assess these relationships over large forested areas. Transects of airborne light detection and ranging (lidar) data, totaling 25,000 km in length, were collected across northern Canada in 2010, providing a unique opportunity to study spatial varia-bility in forest structure. To elucidate on the relationships between fire, productivity, and struc-ture, lidar measures of forest structure were combined with optical satellite indicators of disturb-ance history and forest productivity. Specifically, a 25-year chronosequence of forest regenera-tion following fire was developed, and the relationship between forest structure and productivity was assessed as a function of time since fire. In addition, the relationship between structure and productivity was assessed in stands with no recorded disturbances. Satellite-derived estimates of forest productivity were an important predictor of early stand de-velopment following fire, as lidar-derived estimates of canopy cover varied strongly along re-gional gradients of productivity after 15 years following fire (r = 0.63 – 0.72, p < 0.01). Additionally, pre-disturbance conditions were a strong indicator of stand development following fire, as patches classified as dense forest (> 50% canopy cover) prior to burning displayed faster growth and recovery compared to patches classified as open forest (20 – 50% canopy cover). Further, this research highlights the importance of monitoring multiple aspects of forest recovery, as lidar-derived estimates of canopy cover and stand height showed contrasting relationships to productivity in recently burned stands (1985 – 2009) as well as in stands with no recent disturbance. The results of this dissertation demonstrate the value of the airborne lidar transects for describing stand-level variability in forest structure over large areas, and demonstrate the need for lidar to validate wall-to-wall indicators of disturbance, productivity, and structure.
Adaptive band selection snapshot multispectral imaging in the VIS/NIR domain
Creators: name: Minet, Jean
name: Taboury, Jean
name: Péalat, Michel
name: Roux, Nicolas
name: Lonnoy, Jacques
name: Ferrec, Yann
Publisher: name: arXiv
Year: 2010
Subjects: subject: Optics (physics.optics)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: Hyperspectral imaging has proven its efficiency for target detection applications but the acquisition mode and the data rate are major issues when dealing with real-time detection applications. It can be useful to use snapshot spectral imagers able to acquire all the spectral channels simultaneously on a single image sensor. Such snapshot spectral imagers suffer from the lack of spectral resolution. It is then mandatory to carefully select the spectral content of the acquired image with respect to the proposed application. We present a novel approach of hyperspectral band selection for target detection which maximizes the contrast between the background and the target by proper optimization of positions and linewidths of a limited number of filters. Based on a set of tunable band-pass filters such as Fabry-Perot filters, the device should be able to adapt itself to the current scene and the target looked for. Simulations based on real hyperspectral images show that such snapshot imagers could compete well against hyperspectral imagers in terms of detection efficiency while allowing snapshot acquisition, and real-time detection.
Exploring Hot, Strongly Interacting Matter with the PHENIX Experiment at RHIC
Creators: name: Vertesi, Robert
Publisher: name: Zenodo
Year: 2010
Subjects: qgp
photon
bose-einstein
hadron
η

description: This work summarizes the context and the main milestones of RHIC achievements which culminated in the official announcement of the discovery of the perfect fluid in 2005 and the strongly interacting Quark Gluon Plasma in February 2010. Also several subfields including Bose-Einstein correlation measurements of the bulk matter in PHENIX and connected theoretical work, as well as PHENIX measurements of soft and hard photon and hadron properties are reported.
Determination of the Collins-Soper kernel from cross sections ratios
Creators: name: Martinez, Armando Bermudez
name: Vladimirov, Alexey
Publisher: name: Universität Regensburg
Year: 2022
Subjects: subject: 530 Physik

description: The Collins-Soper kernel is a powerful tool for studying the properties of the QCD vacuum and an essential component of the transverse momentum dependent (TMD) factorization theorem. In this paper, we present a novel method for determining the Collins-Soper kernel directly from the comparison of differential cross sections measured at different energies. The method relies solely on the structure of the TMD factorization theorem and thus also provides a direct test of the theorem validity. With minor modifications, the procedure can be applied to the real measured data for Drell-Yan and SIDIS processes. As a demonstration, we analyze the pseudodata generated by the CASCADE event generator and determine the Collins-Soper kernel suggested by the parton branching model.
A Note on Polytopes for Scattering Amplitudes
Creators: name: Arkani-Hamed, Nima
name: Bourjaily, Jacob L.
name: Cachazo, Freddy
name: Hodges, Andrew
name: Trnka, Jaroslav
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this note we continue the exploration of the polytope picture for scattering amplitudes, where amplitudes are associated with the volumes of polytopes in generalized momentum-twistor spaces. After a quick warm-up example illustrating the essential ideas with the elementary geometry of polygons in CP^2, we interpret the 1-loop MHV integrand as the volume of a polytope in CP^3x CP^3, which can be thought of as the space obtained by taking the geometric dual of the Wilson loop in each CP^3 of the product. We then review the polytope picture for the NMHV tree amplitude and give it a more direct and intrinsic definition as the geometric dual of a canonical "square" of the Wilson-Loop polygon, living in a certain extension of momentum-twistor space into CP^4. In both cases, one natural class of triangulations of the polytope produces the BCFW/CSW representations of the amplitudes; another class of triangulations leads to a striking new form, which is both remarkably simple as well as manifestly cyclic and local.
description: 24 pages, 22 figures
Quasinormal modes of unparticle black holes
Creators: name: Lee, Jong-Phil
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: In the background of unparticle-enhanced black hole geometry, we provide the quasinormal modes of scalar, vector, and Dirac particles around it. Ungravity by tensor unparticles contributes positively to the Newtonian gravity and black holes can be formed at the LHC without any extra dimensions. In the ungravity-dominant regime, the gravity looks much like that of the Schwarzschild geometry in fractional number of extra dimensions. We argue in this analysis that quasinormal modes are good fingerprints to distinguish ungravity from extra dimensions, by showing that the unitarity constraints on ungravity forbid some of the quasinormal modes which are allowed in extra dimensions.
description: 12 pages, 4 figures, 3 tables
Local Integrals for Planar Scattering Amplitudes
Creators: name: Arkani-Hamed, Nima
name: Bourjaily, Jacob L.
name: Cachazo, Freddy
name: Trnka, Jaroslav
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Recently, an explicit, recursive formula for the all-loop integrand of planar scattering amplitudes in N=4 SYM has been described, generalizing the BCFW formula for tree amplitudes, and making manifest the Yangian symmetry of the theory. This has made it possible to easily study the structure of multi-loop amplitudes in the theory. In this paper we describe a remarkable fact revealed by these investigations: the integrand can be expressed in an amazingly simple and manifestly local form when represented in momentum-twistor space using a set of chiral integrals with unit leading singularities. As examples, we present very-concise expressions for all 2- and 3-loop MHV integrands, as well as all 2-loop NMHV integrands. We also describe a natural set of manifestly IR-finite integrals that can be used to express IR-safe objects such as the ratio function. Along the way we give a pedagogical introduction to the foundations of the subject. The new local forms of the integrand are closely connected to leading singularities---matching only a small subset of all leading singularities remarkably suffices to determine the full integrand. These results strongly suggest the existence of a theory for the integrand directly yielding these local expressions, allowing for a more direct understanding of the emergence of local spacetime physics.
description: 84 pages, 118 figures
The targum (1877:Feb.)
Creators: name: No Name Supplied
Publisher: name: Targum Association
Year: 1877

description: Some University historians indicate that the Targum was first published as an annual in 1867, but of this we have no extant evidence. In January 1869, the Targum as we now know it, made its appearance as a monthly paper that concerned itself with student “literary contributions” and college news as well as serving as a vehicle for bringing news to alumni and the general public. The newspaper, which originally was for sale, varied in frequency over the years as did its title (The Targum, Rutgers Targum, Rutgers Daily Targum, and Daily Targum). The newspaper has continuously been published since 1869 with the exception of 19 months during the second world war, between February 1944 and October 1945. The Targum was published by the students of Rutgers College, and later Rutgers University—New Brunswick represented through the years as the Targum Association, Rutgers Targum Association, and Rutgers College Targum. As a student organization, the Targum operated under the oversight of the dean of students and student government but in October 1980, the Targum became an independent college paper.
On the two-dimensionalization of quasistatic magnetohydrodynamic turbulence
Creators: name: Favier, Benjamin F. N.
name: Godeferd, Fabien S.
name: Cambon, Claude
name: Delache, Alexandre
Publisher: name: arXiv
Year: 2011
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We analyze the anisotropy of turbulence in an electrically conducting fluid in the presence of a uniform magnetic field, for low magnetic Reynolds number, using the quasi-static approximation. In the linear limit, the kinetic energy of velocity components normal to the magnetic field decays faster than the kinetic energy of component along the magnetic field [Moffatt, JFM 28, 1967]. However, numerous numerical studies predict a different behaviour, wherein the final state is characterized by dominant horizontal energy. We investigate the corresponding nonlinear phenomenon using Direct Numerical Simulations. The initial temporal evolution of the decaying flow indicates that the turbulence is very similar to the so-called "two-and-a-half-dimensional" flow [Montgomery & Turner, Phys. Fluids 25(2), 1982] and we offer an explanation for the dominance of horizontal kinetic energy.
description: 17 pages, 8 figures
The targum (1877:Jan.)
Creators: name: No Name Supplied
Publisher: name: Targum Association
Year: 1877

description: Some University historians indicate that the Targum was first published as an annual in 1867, but of this we have no extant evidence. In January 1869, the Targum as we now know it, made its appearance as a monthly paper that concerned itself with student “literary contributions” and college news as well as serving as a vehicle for bringing news to alumni and the general public. The newspaper, which originally was for sale, varied in frequency over the years as did its title (The Targum, Rutgers Targum, Rutgers Daily Targum, and Daily Targum). The newspaper has continuously been published since 1869 with the exception of 19 months during the second world war, between February 1944 and October 1945. The Targum was published by the students of Rutgers College, and later Rutgers University—New Brunswick represented through the years as the Targum Association, Rutgers Targum Association, and Rutgers College Targum. As a student organization, the Targum operated under the oversight of the dean of students and student government but in October 1980, the Targum became an independent college paper.
The impacts of High Arctic permafrost disturbances on vegetation and carbon flux dynamics
Creators: name: Cassidy, Alison Elizabeth
Publisher: name: University of British Columbia
Year: 2016

description: Changing climate and disturbance regimes can have widespread ecosystem impacts, especially in the Arctic. Vegetation recovery and carbon flux dynamics were examined to determine the impacts of thermokarst disturbance on patterns and processes in High Arctic tundra ecosystems. Ecosystem responses to two forms of permafrost disturbance, active layer detachment slides and retrogressive thaw slumps, were studied on the Fosheim Peninsula, Ellesmere Island, Canada during the 2012, 2013, and 2014 growing seasons. The impacts of disturbance on vegetation and recovery were determined by sampling active retrogressive thaw slumps and recovered active layer detachment slides that were investigated nearly 20 years ago. Comparison of historic and modern data indicates distinct vegetation communities exist in differently aged disturbances with unique vascular plant species defining various zones and ages of disturbance. Differences were also found in site characteristics (including soil moisture, temperature, active layer depth, and soil nutrient concentrations) indicating the impacts of permafrost disturbance on the landscape. In addition, four active layer detachment slides measured in 1994 had transitioned to active retrogressive thaw slumps, which may be a response to the progressively warming climate. Carbon dioxide fluxes between the surface and the atmosphere were measured using a static chamber system and the eddy covariance technique at three sites on the Fosheim Peninsula. Over the studied growing seasons, disturbed landscapes sequestered significantly less carbon than their surrounding undisturbed tundra. In some sites, this resulted in the shift of the system from a net sink of CO₂ to a net source. A dual eddy covariance sampling approach was found to be preferable over a single tower setup with separation of fluxes based on wind partitioning as disturbed and undisturbed fluxes were simultaneously measured throughout the growing season using this method. Overall, active layer detachments and retrogressive thaw slumps alter vegetation and carbon flux dynamics, and these changes may persist over many years. With predicted increases in the frequency and magnitude of these permafrost disturbances, impacts on tundra ecosystems will be evident at the landscape scale.