cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
XMM Follow-Up Observations of Three Swift BAT-Selected Active Galactic Nuclei
Creators: name: Trippe, M. L.
name: Reynolds, C. S.
name: Koss, M.
name: Mushotzky, R. F.
name: Winter, L. M.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present XMM-Newton observations of three AGN taken as part of a hunt to find very heavily obscured Compton-thick AGN. For obscuring columns greater than 10^25 cm^-2, AGN are only visible at energies below 10 keV via reflected/scattered radiation, characterized by a flat power-law. We therefore selected three objects (ESO 417-G006, IRAS 05218-1212, and MCG -01-05-047) from the Swift BAT hard X-ray survey catalog with Swift X-ray Telescope XRT 0.5-10 keV spectra with flat power-law indices as candidate Compton-thick sources for follow-up observations with the more sensitive instruments on XMM-Newton. The XMM spectra, however, rule out reflection-dominated models based on the weakness of the observed Fe K-alpha lines. Instead, the spectra are well-fit by a model of a power-law continuum obscured by a Compton-thin absorber, plus a soft excess. This result is consistent with previous follow-up observations of two other flat-spectrum BAT-detected AGN. Thus, out of the six AGN in the 22-month BAT catalog with apparently flat Swift XRT spectra, all five that have had follow-up observations are not likely Compton-thick. We also present new optical spectra of two of these objects, IRAS 05218-1212 and MCG -01-05-047. Interestingly, though both these AGN have similar X-ray spectra, their optical spectra are completely different, adding evidence against the simplest form of the geometric unified model of AGN. IRAS 05218-1212 appears in the optical as a Seyfert 1, despite the ~8.5x10^22 cm^-2 line-of-sight absorbing column indicated by its X-ray spectrum. MCG -01-05-047's optical spectrum shows no sign of AGN activity; it appears as a normal galaxy.
description: 18 pages including 4 figures, accepted by ApJ
title: HRCT features in patients with undifferentiated connective tissue disease
Creators: name: Ghinassi, Stefania
Publisher: name: European Congress of Radiology
Year: 2019
Subjects: subject: Lung
subject: Thorax
subject: CT
subject: CT-High Resolution
subject: Diagnostic procedure
subject: Connective tissue disorders

description: Aims and objectives Methods and materials Results Conclusion Personal information References
description: Aims and objectives: Lung involvement is common in connective tissue diseases (CTDs), an heterogeneous group of systemic immunologically mediated inflammatory disorders. [1] As many as 25% of patients with features of a systemic autoimmune disease do not fulfill...
#DontLeaveItToGoogle: How Open Infrastructures Enable Continuous Innovation in the Research Workflow
Creators: name: Kraker, Peter
name: Schramm, Maxi
Publisher: name: Zenodo
Year: 2019
Subjects: open infrastructures
user interfaces
discovery
Open Knowledge Maps
scholarly communication

description: Closed and proprietary infrastructures limit the accessibility of research, often putting paywalls in front of scientific knowledge. But they also severely limit reuse, preventing other tools from building on top of their software, data, and content. Using the example of Google Scholar, I will show how these characteristics of closed infrastructures impede innovation in the research workflow and create lock-in effects. I will also demonstrate how open infrastructures can help us move beyond this issue and create an ecosystem that is community-driven and community-owned. In this ecosystem, innovation thrives, as entry barriers are removed and systems can make use of each other’s components. Specific consideration will be given to open source services and non-profit frontends, as they are often overlooked by funders, but represent the way researchers engage with open science.
Very-high-precision solutions of a class of Schr{ö}dinger equations
Creators: name: Mushtaq, Asif
name: Noreen, Amna
name: Olaussen, Kåre
name: Øverbø, Ingjald
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We investigate a method to solve a class of Schr{ö}dinger equation eigenvalue problems numerically to very high precision $P$ (from thousands to a million of decimals). The memory requirement, and the number of high precision algebraic operations, of the method scale essentially linearly with $P$ when only eigenvalues are computed. However, since the algorithms for multiplying high precision numbers scale at a rate between $P^{1.6}$ and $P\,\log P\,\log\log P$, the time requirement of our method increases somewhat faster than $P^2$.
description: 4 page contribution to proceedings of the Conference on Computational Physics, June 23rd-26th 2010 in Trondheim (submitted to Computer Physics Communications)
Magnetotransport through AFM-defined antidot arrays
Creators: name: Dorn, A.
name: Sigrist, Martin
name: Fuhrer, A.
name: Ihn, Thomas
name: Heinzel, Thomas
name: Ensslin, Klaus
name: Wegscheider, Werner
name: Bichler, Max
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: Antidot lattice; Commensurability peaks; AFM-lithography
subject: 530 Physik

description: Finite antidot arrays were fabricated by atomic force lithography using local anodic oxidation. Low-temperature magnetoresistance measurements on a square 20×20 antidot lattice with a period of a=300 nm showed clear commensurability peaks as well as a quenching of the Hall effect around zero magnetic field. In addition B-periodic oscillations were found superimposed on the main commensurability peak around one antidot at temperatures as high as 1.7 K. These observations indicate the high electronic quality of AFM-defined antidot lattices.
A Simulation Experiment on a Built-In Self Test Equipped with Pseudorandom Test Pattern Generator and Multi-Input Shift Register (MISR)
Creators: name: Ahmad, A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Hardware Architecture (cs.AR)
subject: FOS: Computer and information sciences

description: This paper investigates the impact of the changes of the characteristic polynomials and initial loadings, on behaviour of aliasing errors of parallel signature analyzer (Multi-Input Shift Register), used in an LFSR based digital circuit testing technique. The investigation is carried-out through an extensive simulation study of the effectiveness of the LFSR based digital circuit testing technique. The results of the study show that when the identical characteristic polynomials of order n are used in both pseudo-random test-pattern generator, as well as in Multi-Input Shift Register (MISR) signature analyzer (parallel type) then the probability of aliasing errors remains unchanged due to the changes in the initial loadings of the pseudo-random test-pattern generator.
description: 12 pages,2 figures, Journal
Negative magneto-drag of double layer 2DEGs
Creators: name: Lok, J. G. S.
name: Kraus, Stefan
name: Dietsche, W.
name: Klitzing, Klaus von
name: Schwerdt, F.
name: Hauser, M.
name: Wegscheider, Werner
name: Bichler, Max
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: AlGaAs; Double layer 2DEG; Drag
subject: 530 Physik
subject: 73.20.DX; 73.40.−c

description: We present friction measurements (drag) between two 2DEGs in a magnetic field in the integer quantum Hall regime. At matched densities, the double peak in the drag that occurs when the longitudinal resistances of each 2DEG do not show any sign of spin splitting is observed. For unequal densities in the 2DEGs, a 1/B periodic oscillation around zero appears. Both effects are well described by a phenomenological model assuming a negative drag between electrons with opposite spin and a positive drag between electrons with the same spin. Experiments in tilted magnetic field and on low-mobility samples show that when the spin gap becomes large, the negative drag disappears.
Perturbation theory of the mass enhancement for a polaron coupled to acoustic phonons
Creators: name: Li, Zhou
name: Chandler, Carl J.
name: Marsiglio, F.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We use both a perturbative Green's function analysis and standard perturbative quantum mechanics to calculate the decrease in energy and the effective mass for an electron interacting with acoustic phonons. The interaction is between the difference in lattice displacements for neighbouring ions, and the hopping amplitude for an electron between those two sites. The calculations are performed in one, two, and three dimensions, and comparisons are made with results from other electron-phonon models. We also compute the spectral function and quasiparticle residue, as a function of characteristic phonon frequency. There are strong indications that this model is always polaronic on one dimension, where an unusual relation between the effective mass and the quasiparticle residue is also found.
description: 9 pages, 5 figures, submitted to PRB
Nonlinear superlattice transport limited by Joule heating
Creators: name: Scheuerer, Roland
name: Renk, Karl Friedrich
name: Schomburg, Ekkehard
name: Wegscheider, Werner
name: Bichler, Max
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: gallium arsenide, aluminium compounds, III-V semiconductors, semiconductor superlattices, negative resistance
subject: 530 Physik
subject: 73.63.-b

description: We studied the effects caused by Joule heating in GaAs/AlAs superlattices. We measured the current–voltage characteristics of superlattice mesas of different cross sections. Each current–voltage characteristic showed a corresponding peak current followed by a region of negative differential conductivity, according to miniband transport in the superlattice. We found that Joule heating in the mesa reduced the peak-current density. Current jumps in the region of negative differential conductivity disappeared for large cross-section mesas indicating a suppression of electron domains. The results are of significance for the development of high-power superlattice oscillators for submillimeter radiation.
Cyclotron spin-flip excitations in the 2D-electron system
Creators: name: Kulik, L. V.
name: Kukushkin, I. V.
name: Kirpichev, V. E.
name: Smet, J. H.
name: Klitzing, Klaus von
name: Umansky, V.
name: Wegscheider, Werner
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: Two-dimensional electron gas; Inelastic light scattering; Spin-flip
subject: 530 Physik
subject: 78.66.Fd

description: The cyclotron spin-flip excitations of a two-dimensional electron system have been investigated by inelastic light scattering (ILS). At small electron filling factors, νnot, vert, similar0.1, cyclotron spin-singlet and spin-triplet excitations have been observed, which are the magnetoplasmon and the three possible spin-flip modes that differ by their spin orientations along the axis of the quantizing magnetic field. At larger electron filling factors, ν>0.2, the electron system is fully spin-polarized. The cyclotron spin-wave (CSW) mode reenters in the ILS spectra at an electron filling factor ν>1. The CSW energy is insensitive to both the experimentally accessible in-plane momenta and the electron concentration, whereas its ILS efficiency is strongly influenced by the spin polarization of the electron system.
Seismic performance of bridge piers made of recycled concrete - an experimental study
Creators: name: AL-Hawarneh, Maher Mohammed
Publisher: name: University of British Columbia
Year: 2018

description: Many of the civil infrastructure facilities in Canada have passed their service lives, and are structurally or functionally deficient. Some of these structures will need to be demolished and rebuilt. However, demolition will generate waste whereas new construction will require a huge amount of raw materials. Recycling of construction and demolition (C&D) wastes could be a sustainable solution as it will reduce the economic burden associated with concrete waste disposal, which increases the pressure on landfill capacity and the negative environmental impact. Reusing waste concrete as coarse aggregate, often termed as recycle coarse aggregate (RCA) in the construction industry could reduce the negative environmental impact associated with natural aggregate extraction and transportation. However, before this new recycled concrete is introduced in real life project, it is essential to investigate its properties and performance in structural elements. This study experimentally investigates the seismic performance of reinforced concrete bridge piers made of recycled coarse aggregate (RCA). The conducted test compares the performance of bridge piers made of 100% and 50% RCA with that of 100% natural coarse aggregate (NCA) bridge pier. The bridge under study is a major route bridge located in Vancouver area and is designed as per the Canadian standard. Then the specimen was scaled down to 1/3 of the original bridge pier. The scaled specimens had 300 mm diameter and 1730 mm height. The specimens were tested under quasi-static reverse cyclic loading. Each specimen was subjected to a combination of constant axial loading equal to 10% of its axial capacity and cyclic lateral loading developed by a computer controlled hydraulic actuator. Performance of recycled aggregate concrete (RAC) piers were compared in terms of lateral load capacity, drift, ductility, and energy dissipation capacity with those of conventional concrete pier. Results of this study showed that RAC specimens had improved ductility and lower residual displacements than the control specimen. Moreover, the energy dissipation capacity for 100% RCA specimen was about 11% higher than the control specimen. The results showed that RAC can be effectively used in structural elements in seismic regions.
Quantifying density fluctuations in volumes of all shapes and sizes using indirect umbrella sampling
Creators: name: Patel, Amish J.
name: Varilly, Patrick
name: Chandler, David
name: Garde, Shekhar
Publisher: name: arXiv
Year: 2011
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Water density fluctuations are an important statistical mechanical observable that is related to many-body correlations, as well as hydrophobic hydration and interactions. Local water density fluctuations at a solid-water surface have also been proposed as a measure of its hydrophobicity. These fluctuations can be quantified by calculating the probability, $P_v(N)$, of observing $N$ waters in a probe volume of interest $v$. When $v$ is large, calculating $P_v(N)$ using molecular dynamics simulations is challenging, as the probability of observing very few waters is exponentially small, and the standard procedure for overcoming this problem (umbrella sampling in $N$) leads to undesirable impulsive forces. Patel et al. [J. Phys. Chem. B, 114, 1632 (2010)] have recently developed an indirect umbrella sampling (INDUS) method, that samples a coarse-grained particle number to obtain $P_v(N)$ in cuboidal volumes. Here, we present and demonstrate an extension of that approach to other basic shapes, like spheres and cylinders, as well as to collections of such volumes. We further describe the implementation of INDUS in the NPT ensemble and calculate $P_v(N)$ distributions over a broad range of pressures. Our method may be of particular interest in characterizing the hydrophobicity of interfaces of proteins, nanotubes and related systems.
description: 11 pages, 6 figures
Volatile compounds contributing to the odour of oats
Creators: name: Mustonen, Sari A.
name: Laaksonen, Oskar
name: Linderborg, Kaisa M.
Publisher: name: Zenodo
Year: 2022
Subjects: oat
volatile compounds
odour
flavour
sensory analysis

description: Oats are increasingly popular due to their healthiness, and the number of new different types of oat products on the market is constantly increasing. Oats have higher content of lipids compared to many other grains and therefore their quality and volatile compound profile is susceptible to changes. In this study, selected oat samples were investigated using HS-SPME-GC-O panel and trained sensory panel in order to identify the compounds contributing to the odour characteristics. GC-O panel was trained to describe odours and to evaluate odour intensities of oat samples as flour-water mixtures. The odour and flavour characteristics of the same oat samples were characterised using a sensory panel using generic descriptive analysis. The GC-O panel detected 30 odour-active compounds. The most often described compounds were aldehydes, such as hexanal described as ‘green’ and ‘grassy’, or 3-methylbutanal described as ‘chemical’ and ‘pungent’. At the same time, little differences were observed in ‘green odour’ by the sensory panel, whereas more differences were observed in bitter taste and odour and flavour intensities.
Anomalous temperature dependence of commensurability oscillations in one- and two-dimensional lateral superlattices
Creators: name: Mitzkus, Christian
name: Kangler, W.
name: Weiss, Dieter
name: Wegscheider, Werner
name: Umansky, V.
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: Magnetotransport; Density modulated systems; Lateral superlattices; Commensurability oscillations
subject: 530 Physik
subject: 73.40.−c; 73.50.Jt; 73.23.Ad

description: Two-dimensional electron systems were laterally modulated using the method of in situ interferometric illumination. Magnetotransport measurements on 1D and 2D modulated systems revealed a phase change of the commensurability oscillations depending on temperature. This behaviour is surprising and cannot be explained by existing theories.
The targum (1880:May)
Creators: name: No Name Supplied
Publisher: name: Targum Association
Year: 1880

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.
Measurements of the compressibility of the composite fermion metallic state in a 2D electron system
Creators: name: Dorozhkin, S. I.
name: Smet, J. H.
name: Klitzing, Klaus von
name: Umansky, V.
name: Wegscheider, Werner
name: Haug, R. J.
name: Ploog, K.
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: Fractional quantum Hall effect; Composite fermions; Compressibility
subject: 530 Physik
subject: 72.20.Fr; 72.20.My; 73.40.Kp

description: It is well-established that the electron–electron interaction strongly affects the compressibility of a two-dimensional electron system at zero magnetic field and even leads to the negative sign of the compressibility. Surprisingly, we find that its contribution is almost identical for the metallic states of electrons at zero magnetic field and of composite fermions at Landau level filling 1/2.
Gravity from a fermionic condensate of a gauge theory
Creators: name: Randono, Andrew
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The most prominent realization of gravity as a gauge theory similar to the gauge theories of the standard model comes from enlarging the gauge group from the Lorentz group to the de Sitter group. To regain ordinary Einstein-Cartan gravity the symmetry must be broken, which can be accomplished by known quasi-dynamic mechanisms. Motivated by symmetry breaking models in particle physics and condensed matter systems, we propose that the symmetry can naturally be broken by a homogenous and isotropic fermionic condensate of ordinary spinors. We demonstrate that the condensate is compatible with the Einstein-Cartan equations and can be imposed in a fully de Sitter invariant manner. This lends support, and provides a physically realistic mechanism for understanding gravity as a gauge theory with a spontaneously broken local de Sitter symmetry.
description: 16 pages
Quantum wires and quantum dots defined by lithography with an atomic force microscope
Creators: name: Lüscher, S.
name: Fuhrer, A.
name: Held, R.
name: Heinzel, Thomas
name: Ensslin, Klaus
name: Bichler, Max
name: Wegscheider, Werner
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: Atomic force microscope; Nanostructures; Lithography
subject: 530 Physik

description: Semiconductor nanostructures are realized by patterning AlGaAs/GaAs heterostructures with an atomic force microscope. Steep potential walls, precise pattern transfer and a combination of in-plane and top gates can be achieved with this technique. The electronic properties of nanostructures defined in this way are discussed on two examples, namely a quantum point contact and a single electron transistor. For the quantum point contact we demonstrate quantized conductance at temperatures of 4 K and above. This indicates the strong confinement energy in this system. For the single electron transistor, the realization of special potential shapes and the observation of high-quality Coulomb blockade is shown.
Towards a bulk theory of flexoelectricity
Creators: name: Resta, R.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Flexoelectricity is the linear response of polarization to a strain gradient. Here we address the simplest class of dielectrics, namely elemental cubic crystals, and we prove that therein there is no extrinsic (i.e. surface) contribution to flexoelectricity in the thermodynamic limit. The flexoelectric tensor is expressed as a bulk response of the solid, manifestly independent of surface configurations. Furthermore, we prove that the flexoelectric responses induced by a long-wavelength phonon and by a uniform strain gradient are identical.
description: 5 pages, 1 figure (2 panels)
Local spectroscopy of edge channels in the quantum Hall regime with local probe techniques
Creators: name: Ihn, Thomas
name: Rychen, J.
name: Vancura, T.
name: Ensslin, Klaus
name: Wegscheider, Werner
name: Bichler, Max
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: Quantum Hall effect; Edge channels; Scanning probe techniques
subject: 530 Physik

description: We present measurements of the tunnelling conductance between edge channels in the quantum Hall regime. By using a local potential perturbation induced by the tip of a scanning force microscope we are able to enhance the tunnelling coupling and map its strength along the edge of the two-dimensional electron gas. It is suggested that the presented method is promising for the local investigation of inter-edge-channel scattering and edge-channel equilibration.
At what cost? a study of Canada's first public-private post-secondary matriculation pathways partnership
Creators: name: Maschmann, Elizabeth
Publisher: name: University of British Columbia
Year: 2018

description: This study explores Canada’s first private-public matriculation pathways partnership into higher education at the juncture of its ten-year anniversary. In 2006, Simon Fraser University (SFU), a mid-sized, public Canadian research university entered into partnership with Navitas, a private, for-profit, multinational education services provider. The partnership authorized the establishment of Fraser International College (FIC), on SFU’s main campus in Burnaby, British Columbia. Although the partnership was controversial, university administration justified the collaboration as providing enhanced recruitment of international students, financial gains through profit sharing and differential international student tuition fees, and enhanced academic and social supports for students. Unlike previous outsourcing to the private sector in Canadian higher education, the SFU-FIC/Navitas partnership allowed for in-roads into core academic functions of the university. Since its inception, FIC/Navitas has extended its purview by claiming delivery of English for Academic Purposes (EAP) language instruction once located in SFU’s Faculty of Arts and Social Sciences. Theoretically, literature on globalization and internationalization of higher education as informed by neo-liberal ideology are employed and intersect with literature on the role of EAP. As university websites have come to have significant discursive influence and international reach, methodologically, this research combines qualitative case study with multimodal critical discourse analysis of SFU-FIC/Navitas partnership web pages. My primary findings reveal that the public and private partners share promotional discourses of marketization to their external market. However, there are some differences. The public partner, SFU, also relies on more traditional academic and social discourses of community, access, and inclusion when addressing local audiences while the private partner, FIC/Navitas, relies on the social and academic capital generated by the public partner, SFU, for legitimacy and growth. I also found discourses present on SFU and FIC/Navitas websites point to contradictions with potential to impact both students and staff. Further findings indicate that the ongoing marginalization of EAP programs within the university provided an opening for FIC to grow its presence and profitability.
Magnetotransport in freely suspended two-dimensional electron systems for integrated nanomechanical resonators
Creators: name: Höhberger, E. M.
name: Blick, Robert H.
name: Beil, F. W.
name: Wegscheider, Werner
name: Bichler, Max
name: Kotthaus, J. P.
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: GaAs/AlGaAs-heterostructures; Nano-electromechanical systems (NEMS)
subject: 530 Physik
subject: 73.20.Dx; 73.40.−c

description: We present magnetotransport measurements on freely suspended two-dimensional electron gases. Samples are prepared from GaAs/AlGaAs-heterostructures containing an additional sacrificial layer. The electronic properties of the system are characterized in standard magnetotransport measurements whereas the mechanical degrees of freedom are investigated in radio frequency resonance experiments. The interplay of both can be exploited for ultrasensitive displacement detection.
Modelling chromospheric line profiles as diagnostics of velocity fields in ω Centauri red giant stars
Creators: name: Vieytes, M.
name: Mauas, P.
name: Cacciari, C.
name: Origlia, L.
name: Pancino, E.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context. Mass loss of ~0.1-0.3 M$_{\odot}$ from Population II red giant stars (RGB) is a requirement of stellar evolution theory in order to account for several observational evidences in globular clusters. Aims. The aim of this study is to detect the presence of outward velocity fields, which are indicative of mass outflow, in six luminous red giant stars of the stellar cluster ω Cen. Methods. We compare synthetic line profiles computed using relevant model chromospheres to observed profiles of the Hα and Ca II K lines. The spectra were taken with UVES (R=45,000) and the stars were selected so that three of them belong to the metal-rich population and three to the metal-poor population, and sample as far down as 1 to 2.5 magnitudes fainter than the respective RGB tips. Results. We do indeed reveal the presence of low-velocity outward motions in four of our six targets, without any apparent correlation with astrophysical parameters. Conclusions. This provides direct evidence that outward velocity fields and mass motions exist in RGB stars as much as 2.5 mag fainter than the tip. On the assumption that the mass outflow may eventually lead to mass loss from the star, we estimate mass-loss rates of some 10^{-9}-10^{-10} M$_{\odot}$ yr^{-1} that are compatible with the stellar evolution requirements. These rates seem to be correlated with luminosity rather than metallicity.
description: Accepted by A&A
Scanning gate measurements on a quantum wire
Creators: name: Ihn, Thomas
name: Rychen, J.
name: Cilento, T.
name: Held, R.
name: Ensslin, Klaus
name: Wegscheider, Werner
name: Bichler, Max
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: Scanning probe techniques; Quantum wires; Phase coherence effects
subject: 530 Physik
subject: 73.40.Gk

description: We have performed measurements on a semiconductor quantum wire in which we induce a local potential perturbation with the metallic tip of a scanning force microscope. Measurement of the sample resistance as a function of tip position results in an electrical map of the wire in real space. We find the fingerprint of potential fluctuations in the wire which appear as local resistance fluctuations in the images. In a local transconductance measurement we observe small oscillations on the scale of the Fermi-wavelength of electrons which may arise from interference of electron waves.
Spin polarized tunneling through single-crystal GaAs(001) barriers
Creators: name: Kreuzer, Sebastian
name: Moser, Jürgen
name: Wegscheider, Werner
name: Weiss, Dieter
name: Bichler, Max
name: Schuh, Dieter
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: 530 Physik

description: We investigate spin-dependent transport through an epitaxial GaAs(001) barrier sandwiched between polycrystalline iron films. Electron transport through the barrier is dominated by quantum mechanical tunneling, demonstrated by a nonlinear I–V characteristic, an exponential dependence of the tunneling current on the barrier thickness and the temperature dependence of the current. Though small a clear tunneling magnetoresistance effect proves spin-dependent transport through the Fe–GaAs interface. The small size of the effect and the high-field magnetoresistance suggest that spin–flip scattering plays a decisive role in transport.
Data Stewardship-Why and How?
Creators: name: Velden, Yasemin Turkyilmaz-Van Der
Publisher: name: Zenodo
Year: 2019

description: Talk about the why and how of Data Stewardship at Hogeschool Rotterdam Biology and Medical Laboratory Research with a perspective about motivations for open science, FAIR Data principles and the roles technicians can play in avoiding the Reproducibility Crisis.
Localization of proliferating cell nuclear antigen, vimentin, c-Fos, and clusterin in the postischemic kidney. Evidence for a heterogenous genetic response among nephron segments, and a large pool of mitotically active and dedifferentiated cells
Creators: name: Witzgall, Ralph
name: Brown, Dennis
name: Schwarz, Cordula
name: Bonventre, Joseph V.
Publisher: name: Universität Regensburg
Year: 1994
Subjects: subject: 610 Medizin

description: The mechanisms leading to the recovery of the kidney after ischemic acute renal failure are poorly understood. To explore the role played by mitogenesis and dedifferentiation in this repair process and to identify whether the genetic response of the nephron segments reflects the level of susceptibility to injury, the temporal and nephron segment expressions of various proteins implicated in mitogenesis, differentiation, and injury were determined. Proliferating cell nuclear antigen (PCNA), a marker for the G1-S transition in the cell cycle and hence mitogenesis, was detected primarily in the S3 segment of the proximal tubule, with maximal expression at 2 d postischemia. Vimentin, normally present in mesenchymal cells but not epithelial cells, and hence a marker for the state of differentiation, was prominently expressed in the S3 segment 2-5 d postischemia. In the S3 segments in the outer stripe of the medulla cells that stained positively for PCNA also stained positively for vimentin. Clusterin, a marker for cell injury, was expressed primarily in the S3 segment and in the distal tubule with distinct staining patterns in each segment. None of the cells that stained with clusterin antibodies were positively stained with PCNA or vimentin antibodies. Likewise, none of the PCNA or vimentin-positive cells expressed clusterin at detectable levels. Thus, in the S3 segment, where there is significant ischemic injury, surviving cells express markers indicating that they undergo mitogenesis and dedifferentiate in the postischemic period. While there is some expression of c-Fos in the S3 segment, c-Fos was expressed predominantly, at 1 and 3 h postischemia, in the nuclei of the distal nephron, particularly in the thick ascending limb. The data support the view that the mature renal S3 segment epithelial cell can be a progenitor cell.
Pyrite formation linked with hydrogen evolution under anaerobic conditions
Creators: name: Drobner, E.
name: Huber, Harald
name: Wächtershäuser, G.
name: Rose, D.
name: Stetter, Karl Otto
Publisher: name: Universität Regensburg
Year: 1990
Subjects: subject: 570 Biowissenschaften, Biologie

description: THE formation of pyrite (FeS2), an important factor in determining the global redox balance1, has recently attracted biological interest as a possible direct source of energy for early life2–5. The theory implies that carbon dioxide fixation, in competition with hydrogen formation, can serve as the electron sink for pyrite formation and it seems to be supported by the detection of minute grains of pyrite and iron sulphides inside bacteria5–8. Yet it clashes with the conventional assumption that elemental sulphur or a sulphur equivalent (polysulphide or thiosulphate) is the mandatory oxidant for pyrite formation9,10. It has been stressed that the reaction FeS + H2Sright arrowFeS2 + H2 (with H+ as the oxidant) has "never been observed ... during several years of experimentation"10. Here we report the formation of both pyrite and molecular hydrogen under fastidiously anaerobic conditions in the aqueous system of FeS and H2S.
Associative control processor with a rigid structure
Creators: name: Magomedov, Isa
name: Khazamov, Omar
Publisher: name: arXiv
Year: 2010
Subjects: subject: Hardware Architecture (cs.AR)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences
subject: B.2.1

description: The approach of applying associative processor for decision making problem was proposed. It focuses on hardware implementations of fuzzy processing systems, associativity as effective management basis of fuzzy processor. The structural approach is being developed resulting in a quite simple and compact parallel associative memory unit (PAMU). The memory cost and speed comparison of processors with rigid and soft-variable structure is given. Also the example PAMU flashing is considered.
description: 16 pages, 7 figures
Risk capital allocation for RORAC optimization
Creators: name: Buch, Arne
name: Dorfleitner, Gregor
name: Wimmer, Maximilian
Publisher: name: Universität Regensburg
Year: 2011
Subjects: subject: Risk capital; Economic capital; Capital allocation; Gradient allocation; Euler allocation; RORAC
subject: 330 Wirtschaft
subject: C61
subject: D81
subject: D82
subject: G21
subject: G22

description: This paper considers the financial optimization problem of a firm with several sub-businesses striving for its optimal RORAC. An insightful example shows that the implementation of classical gradient capital allocation can be suboptimal if division managers are allowed to venture into all business whose marginal RORAC exceeds the firm's RORAC. The marginal RORAC requirements are refined by adding a risk correction term that takes into account the interdependencies of the risks of different lines of business. It is shown that under certain stationarity conditions this approach can guarantee that the optimal RORAC will eventually be achieved.
Spin-Sensitive Bleaching and Monopolar Spin Orientation in Quantum Wells
Creators: name: Ganichev, Sergey
name: Danilov, Sergey
name: Belkov, Vassilij
name: Ivchenko, Eougenious
name: Wegscheider, Werner
name: Weiss, Dieter
name: Bichler, Max
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: 530 Physik
subject: 78.30.Fs, 68.65.-k, 73.50.Mx, 73.50.Pz

description: Spin-sensitive bleaching of the absorption of far-infrared radiation has been observed in p-type GaAs/AlGaAs quantum well structures. The absorption of circularly polarized radiation saturates at lower intensities than that of linearly polarized light due to monopolar spin orientation in the first heavy-hole subband. Spin relaxation times of holes in p-type material in the range of tens of ps were derived from the intensity dependence of the absorption.
Band-gap renormalization of modulation-doped quantum wires
Creators: name: Sedlmaier, S.
name: Stopa, M.
name: Schedelbeck, Gert
name: Wegscheider, Werner
name: Abstreiter, Gerhard
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: 530 Physik
subject: 78.66.-w, 71.15.Mb, 71.35.-y, 85.35.Be

description: We measure the photoluminescence spectra for an array of modulation doped, T-shaped quantum wires as a function of the one-dimensional density ne, which is modulated with a surface gate. We present self-consistent electronic structure calculations for this device which show a band-gap renormalization which, when corrected for excitonic energy and its screening, are largely insensitive to ne and which are in quantitatively excellent agreement with the data. The calculations show that electron and hole remain bound up to ∼3×106 cm-1 and that, therefore, the stability of the exciton far exceeds the conservative Mott criterion, as determined from the Bethe-Salpeter equation.
title: Universität Kassel, Vorlesungsverzeichnis WiSe 2016 / 2017
Creators: name: (:Unkn) Unknown
Publisher: name: Universität Kassel
Year: 2016
Subjects: subject: 350
subject: 370
subject: Universität Kassel
subject: Vorlesungsverzeichnis

description: PDF zum Online-Vorlesungsverzeichnis
Miniband transport in vertical superlattice field effect transistors
Creators: name: Deutschmann, R. A.
name: Wegscheider, Werner
name: Rother, Martin
name: Bichler, Max
name: Abstreiter, Gerhard
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: Lateral superlattice; Field effect transistor; Negative differential resistance
subject: 530 Physik
subject: 73.21.Cd; 73.63.Hs

description: The non-equilibrium transport of electrons confined at an atomically sharp interface and subject to a periodic potential is studied. We find a pronounced negative differential resistance, the magnitude of which increases with increasing modulation strength. The data is qualitatively consistent with the Esaki–Tsu transport model. We emphasize the significance of the two-dimensionality of the electron system and the gate to inhibit domain formation. Additional features in the source–drain current are attributed to Bloch-phonon resonances.
Measurements of time-dependent CP asymmetries in $B \to D^{*\mp} π^{\pm}$ decays using a partial reconstruction technique
Creators: name: Bahinipati, S.
name: Trabelsi, K.
name: Kinoshita, K.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We report results on time-dependent CP asymmetries in $B \to D^{*\mp}π^{\pm}$ decays based on a data sample containing 657 {\times} $10^6$ $B\bar{B}$ pairs collected with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider at the $Υ(4S)$ resonance. We use a partial reconstruction technique, wherein signal $B \to D^{*\mp}π^{\pm}$ events are identified using information only from the fast pion from the B decay and the slow pion from the subsequent decay of the $D^{*\mp}$, where the former (latter) corresponds to $D^{*+} (D^{*-})$ final states. We obtain CP violation parameters $S^+ = +0.061 \pm 0.018(\mathrm{stat}) \pm 0.012(\mathrm{syst})$ and $S^- = +0.031 \pm 0.019(\mathrm{stat}) \pm 0.015(\mathrm{syst})$.
description: 8 pages, 5 figures, 2 tables, submitted to Physical Review D (RC)
A new trend in aromatic sample preparation: Vacuum Assisted Sorbent Extraction (VASE) applied to pet food aroma analysis
Creators: name: Le Guillas, Gautier
name: Marzin, Cécile
name: Hanaoka, Karine
name: Guilloux, Marion
name: Pétel, Cécile
name: Callejon, Laurence
name: Villière, Angélique
name: Prost, Carole
name: Lethuaut, Laurent
Publisher: name: Zenodo
Year: 2022
Subjects: aroma compounds
vacuum extraction
sorbent pen
sample preparation
extruded pet food

description: Aroma compounds extraction remains challenging to ensure a proper detection of volatile compounds when determination of the overall composition of the aroma is needed. Recently emerged, the Vacuum Assisted Sorbent Extraction (VASE) strives for a wider range of detection of the food aroma composition by combining high sensitivity traps and the benefits of a vacuumed environment. The present work aimed to compare abilities of three different available adsorbent phases combined to VASE technic on the extraction of volatile compounds from a meat flavoured extruded dry pet food. Two extraction times under vacuum (4h and 24h) were also compared for each adsorbent phase to highlight the importance of an appropriate extraction time. A higher extraction time enabled a significantly better volatile compounds detection (higher number of compounds and higher mean peak areas; p-value < 0.001) as well as an improvement of repeatability, reducing by more than half the coefficient of variation. A relevant impact of the adsorbent phase has also stood out (p-value < 0.001) and specificities were spotted. Whatever adsorbent type, a common pattern composed of 33 compounds, on a total of 100 identified, was extracted, probably due to the Tenax® TA contained by the three adsorbent phases. The Carboxen 1000 supplemented Tenax TA adsorbent trap favoured extraction of additional nitrogen and carbonyl compounds whereas the CarbopackTM X supplemented one ended up to be the less efficient except for low boiling point (<100°C) volatile compounds. Therefore, the adsorbent phase should be carefully selected depending on the nature of the volatile compounds suspected in the product.
Quantum criticality in the SO(5) bilinear-biquadratic Heisenberg chain
Creators: name: Alet, F.
name: Capponi, S.
name: Nonne, H.
name: Lecheminant, P.
name: McCulloch, I. P.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The zero-temperature properties of the SO(5) bilinear-biquadratic Heisenberg spin chain are investigated by means of a low-energy approach and large scale numerical calculations. In sharp contrast to the spin-1 SO(3) Heisenberg chain, we show that the SO(5) Heisenberg spin chain is dimerized with a two-fold degenerate ground state. On top of this gapful phase, we find the emergence of a non-degenerate gapped phase with hidden (Z$_2$ $\times$ Z$_2$)$^2$ symmetry and spin-3/2 edge states that can be understood from a SO(5) AKLT wave function. We derive a low-energy theory describing the quantum critical point which separates these two gapped phases. It is shown and confirmed numerically that this quantum critical point belongs to the SO(5)$_1$ universality class.
description: 4 pages, 4 figures
Unusual Phase Transitions and Magnetoelastic Coupling in TlFe1.6Se2 Single Crystals
Creators: name: Sales, Brian C.
name: McGuire, Michael A.
name: May, Andrew F.
name: Cao, Huibo
name: Chakoumakos, Bryan C.
name: Sefat, Athena S.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Structural, magnetic, electrical transport, and heat capacity data are reported for single crystals of TlFe1.6Se2. This compound crystallizes in a tetragonal structure similar to the ThCr2Si2 structure, but with vacancies in the Fe layer. The vacancies can be ordered or disordered depending on temperature and thermal history. If the vacancies are ordered, the basal plane lattice constant increases from a to \sqrt{5}a. Antiferromagnetic order with the Fe spins along the c-axis occurs below T_N ~ 430K as shown by single crystal neutron diffraction and the magnetic structure is reported. In addition, for the vacancy ordered crystal, two other phase transitions are found at T_1 ~ 140K, and T_2 ~ 100K. The phase transitions at T_1 and T_2 are evident in heat capacity, magnetic susceptibility, resistivity data, a and c lattice parameters, and in the unusual temperature dependence of the magnetic order parameter determined from neutron scattering. The phase transitions at T_1 and T_2 result in significant changes in the magnetic moment per iron, with 1.72(6)μ_B observed at 300K, 2.07(9)μ_B at 140\,K, 1.90(9)\,μ_B at 115\,K, and 1.31(8)μ_B for 5\,K if the same "block checkerboard" magnetic structure is used at all temperatures. The phase transitions appear to be driven by small changes in the c lattice constant, large magnetoelastic coupling, and the localization of carriers with decreasing temperature.
description: Accepted for publication in Physical Review B