cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
High temperature thermoelectric response of double-doped SrTiO$_3$ epitaxial films
Creators: name: Ravichandran, Jayakanth
name: Siemons, Wolter
name: Oh, Dong-wook
name: Kardel, Justin T.
name: Chari, Arvind
name: Heijmerikx, Herman
name: Scullin, Matthew L.
name: Majumdar, Arun
name: Ramesh, Ramamoorthy
name: Cahill, David G.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: SrTiO$_3$ is a promising $n$-type oxide semiconductor for thermoelectric energy conversion. Epitaxial thin films of SrTiO$_3$ doped with both La and oxygen vacancies have been synthesized by pulsed laser deposition (PLD). The thermoelectric and galvanomagnetic properties of these films have been characterized at temperatures ranging from 300 K to 900 K and are typical of a doped semiconductor. Thermopower values of double-doped films are comparable to previous studies of La doped single crystals at similar carrier concentrations. The highest thermoelectric figure of merit ($ZT$) was measured to be 0.28 at 873 K at a carrier concentration of $2.5\times10^{21}$ cm$^{-3}$.
description: Published version, 6 pages, 6 figures link: http://prb.aps.org/abstract/PRB/v82/i16/e165126
AC-driven phase-dependent directed diffusion
Creators: name: Yevtushenko, Oleg
name: Flach, Sergej
name: Richter, Klaus
Publisher: name: Universität Regensburg
Year: 2000
Subjects: subject: 530 Physik

description: We study directed diffusion of a particle in a periodic symmetric potential under the influence of a time-periodic external field. The field lowers the symmetry of the phase space flow which results in directed diffusion even if the potential and the field are reflection symmetric. We analyze the interplay between broken symmetry and dynamical chaos.
A new species of Noblella (Amphibia: Strabomantidae) from the Río Manduriacu Reserve on the Pacific slopes of the Ecuadorian Andes
Creators: name: Reyes-Puig, Carolina
name: Maynard, Ross J.
name: Trageser, Scott J.
name: Vieira, José
name: Hamilton, Paul S.
name: Lynch, Ryan
name: Culebras, Jaime
name: Kohn, Sebastián
name: Brito, Jorge
name: Guayasamin, Juan M.
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: FOS: Biological sciences
subject: Developmental Biology
subject: Marine Biology
subject: Inorganic Chemistry
subject: Plant Biology
subject: Computational Biology
subject: Cardiology

description: With the third most biodiverse amphibian fauna in the world, Ecuador has bolstered this claim with a particularly high rate of species descriptions in recent years. Many of the species being described are already facing anthropogenic threats despite being discovered within privately protected reserves in areas previously not sampled. Herein we describe a new species of terrestrial frog in the genus Noblella from the recently established Río Manduriacu Reserve, Imbabura, Ecuador. Noblella worleyae sp. nov. differs from its congeners by having a dorsum finely shagreen; tips of Fingers I and IV slightly acuminate, Fingers II and III acuminate, without papillae; distal phalanges of the hand slightly T-shaped; absence of distinctive suprainguinal marks; venter yellowish-cream with minute speckling and throat with irregular brown marks to homogeneously brown. We provide a detailed description of the advertisement call of the new species and present an updated phylogeny of the genus Noblella. In addition, we emphasize the importance of the Río Manduriacu Reserve as a conservation area to threatened fauna. Ecuador es el tercer país más diverso en anfibios, y la descripción de especies en los últimos años ha aumentado considerablemente, evidenciando la presencia de nuevas especies en áreas privadas protegidas, muchas de las cuales enfrentan amenazas antropogénicas. Aquí describimos una nueva especie de rana terrestre del género Noblella de la vertiente pacífica de los Andes ecuatorianos en la Reserva Río Manduriacu, provincia de Imbabura. Noblella worleyae sp. nov. se diferencia de sus congéneres por la presencia de un dorso finamente granular, puntas de los dedos I y IV ligeramente acuminados, dedos II y III acuminados, sin papila; falanges distales de la mano ligeramente en forma de T; ausencia de marcas distintivas suprainguinales; vientre crema amarillento moteado con diminutos puntos ,garganta con marcas cafés irregulares a homogéneamente café. Proporcionamos una descripción detallada del canto de la nueva especie y presentamos una filogenia actualizada del género Noblella. Además, enfatizamos la importancia de la Reserva Río Manduriacu como un área de conservación para fauna amenazada.
Testing Lorentz Invariance by Comparing Light Propagation in Vacuum and Matter
Creators: name: Nagel, M.
name: Möhle, K.
name: Döringshoff, K.
name: Herrmann, S.
name: Senger, A.
name: Kovalchuk, E. V.
name: Peters, A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We present a Michelson-Morley type experiment for testing the isotropy of the speed of light in vacuum and matter. The experiment compares the resonance frequency of a monolithic optical sapphire resonator with the resonance frequency of an orthogonal evacuated optical cavity made of fused silica while the whole setup is rotated on an air bearing turntable once every 45 s. Preliminary results yield an upper limit for the anisotropy of the speed of light in matter (sapphire) of Δc/c < 4x10^(-15), limited by the frequency stability of the sapphire resonator operated at room temperature. Work to increase the measurement sensitivity by more than one order of magnitude by cooling down the sapphire resonator to liquid helium temperatures (LHe) is currently under way.
description: Presented at the Fifth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 28-July 2, 2010
Electron transport in nanotube-molecular wire hybrids
Creators: name: Fagas, Giorgos
name: Cuniberti, Gianaurelio
name: Richter, Klaus
Publisher: name: Universität Regensburg
Year: 2001
Subjects: subject: 530 Physik

description: We study contact effects on electron transport across a molecular wire sandwiched between two semi-infinite (carbon) nanotube leads as a model for nanoelectrodes. Employing the Landauer scattering matrix approach, we find that the conductance is very sensitive to parameters such as the coupling strength and geometry of the contact. The conductance exhibits markedly different behavior in the two limiting scenarios of single contact and multiple contacts between the molecular wire and the nanotube interfacial atoms. In contrast to a single contact, the multiple-contact configuration acts as a filter selecting single transport channels. It exhibits a scaling law for the conductance as a function of coupling strength and tube diameter. We also observe an unusual narrow-to-broad-to-narrow behavior of conductance resonances upon decreasing the coupling.
Coulomb Blockade Peak Spacing Fluctuations in Chaotic Quantum Dots
Creators: name: Ahn, Kang-Hun
name: Richter, Klaus
Publisher: name: Universität Regensburg
Year: 2000
Subjects: subject: 530 Physik

description: We study ground states of interacting electrons in classically chaotic quantum dots using exact diagonalization and the self-consistent Hartree– Fock (SCHF) method. We find good agreement between both methods with respect to energies and charge densities. With increasing interaction the ground states show a crystal-type structure which originates from the interplay between direct and exchange interaction and the confinement. Corresponding capacitive energies exhibit fluctuations which are strongly enhanced with increasing interaction.
Fast algorithms for computing defects and their derivatives in the Regge calculus
Creators: name: Brewin, Leo
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Any practical attempt to solve the Regge equations, these being a large system of non-linear algebraic equations, will almost certainly employ a Newton-Raphson like scheme. In such cases it is essential that efficient algorithms be used when computing the defect angles and their derivatives with respect to the leg-lengths. The purpose of this paper is to present details of such an algorithm.
description: 38 pages, 10 figures
Semiclassical analysis of level widths for one-dimensional potentials
Creators: name: Ingold, Gert-Ludwig
name: Jalabert, Rodolfo A.
name: Richter, Klaus
Publisher: name: Universität Regensburg
Year: 2001
Subjects: subject: 530 Physik

description: We present a semiclassical study of level widths for a class of one-dimensional potentials in the presence of an ohmic environment. Employing an expression for the dipole matrix element in terms of the Fourier transform of the classical path we obtain the level widths within the Golden rule approximation. It is found that for potentials with an asymptotic power-law behavior, which may in addition be limited by an infinite wall, the width that an eigenstate of the isolated system acquires due to the coupling to the environment is proportional to its quantum number.
O'ZBEKISTON RESPUBLIKASI TA'LIM TIZIMI VA TURLARNING TASNIFI
Creators: name: Qoqon Davlat pedagogika instituti Boshlangich talim fakulteti  Fakultetlararo pedagogika va psihologiya kafedra katta oqituvchisi  Karimova Mukarramhon Xalimovna Xaydarov Abdushukur Sodirjon ugli   matematika 101 Qosimova Aloxon Jaxongir qizi
Publisher: name: Zenodo
Year: 2023

description: Maqolada pedagogika fanlari tizimining muhim tarmog'i sifatida maxsus fanlarni o'qitish shartlarini o'rganuvchi metodik xizmat ko'rsatilgan. Pedagogika fanining ob'ekti yil sayin kengayib bormoqda, buning natijasida uning tarmoqlari ham bir necha guruhlarga bo'linadi, ular pedagogika fanlari tizimi deb ataladi. Ma'lumki, bu pedagogika fanlari tizimining muhim tarmog'i, maxsus fanlarni o'qitish shartlarini o'rganuvchi tizimli fandir.
Tayanch so'zlar:
 tizim, tarmoq, qonuniylik, fan, ob'ekt, bilim
The Significance of Ethnography in Youth Participation Research: Active Citizenship in the UK after the Brexit Vote
Creators: name: Banaji, Shakuntala
name: Mejias, Sam
name: De La Pava Vélez, Benjamín
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2018
Subjects: M-PSI/05 Psicologia sociale

description: In comparison to questionnaires, statistical analyses, interviews and experiments, ethnography tends to be a neglected method in youth participation research and in understanding political socialization and citizen action. This, we suggest, is very unfortunate. Where the concerns and experiences of researchers do not match those of young people, it is usually the young people’s perspectives which remain outside the frameworks and conclusions. Drawing on original data and insights from two ethnographies of youth active citizenship initiatives in the UK – My Life My Say and Momentum – collected during a politically tumultuous 8-month period in 2017, this article argues that ethnography has several advantages over other methods when it comes to understanding the depth and significance of youth civic participation and its links to peer groups and emotions. We contend that critical and reflexive ethnographies allow scholars and researchers to ask and probe young people’s perceptions, opinions, actions and behaviours through the use of open-ended questions in settings where civic action is already taking place, thus triangulating findings in natural settings and building a sense of how communities of practice and activism function. In terms of ethics, voice and power, this ethnographic research approach gives young people more control over their own narratives about participation and affiliation in specific political or civic settings than surveys tend to do.
The Poincare-Birkhoff theorem in Quantum Mechanics
Creators: name: Wisniacki, D. A.
name: Saraceno, M.
name: Arranz, F. J.
name: Benito, R. M.
name: Borondo, F.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum manifestations of the dynamics around resonant tori in perturbed Hamiltonian systems, dictated by the Poincaré--Birkhoff theorem, are shown to exist. They are embedded in the interactions involving states which differ in a number of quanta equal to the order of the classical resonance. Moreover, the associated classical phase space structures are mimicked in the quasiprobability density functions and their zeros.
description: 5 pages, 3 figures, Full resolution figures available at http://www.df.uba.ar/users/wisniaki/publications.html
31940: Reading for lockdown
Creators: name: Project, Lockdown2020 and Beyond
Publisher: name: University of Oxford
Year: 2023
Subjects: classificationCode: 479999
subject: Other language, communication and culture not elsewhere classified

description: During lockdown, teaching and having meetings online has kept me pretty busy. Our students have been brilliant - understanding, flexible, and accommodating. I'm spending a lot of the day online and have become surprising comfortable with Microsoft Teams, Zoom, Panopto, and so on, but I noticed that there were a lot of requests for reading suggestions on social media, so I asked my lovely communications and events colleagues if we could host a 'literary clinic', and they made it happen. I receive the enquiries and answer by email. So far I've had requests for crime novels with no gore, intelligent romances, armchair travel, novels about the sea, non-linear novels with a different perspective, stories about Canada from two hundred years ago, and many more. https://www.conted.ox.ac.uk/about/literary-clinic
Can personalized carbon calculators promote lower-emission lifestyle intentions?
Creators: name: Hanson-Wright, Brynley
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Environmental Studies
subject: Social and Behavioral Sciences
subject: Psychology
subject: FOS: Psychology
subject: behavioural sustainability
subject: behaviour change
subject: carbon calculator
subject: climate action
subject: climate change
subject: decision making

description: Climate change is driven in part by the lifestyle choices individuals make every day and yet the emissions associated with these decisions are seldom considered and are challenging for people to conceptualize. Personal carbon calculators offer a unique opportunity to provide people with information about the climate-cost of different actions alongside tailored guidance for lowering one’s own impact. This project will use a randomized control trial to evaluate how effective this tool may be for promoting climate action. Behavioural intentions for 2023 and reported behaviours in 2019 will be used to quantify a change in carbon footprint—including domains of food, transportation, housing, and material purchases—and we will compare how this intended shift in emissions differs between groups.
Characterisation of 15 overlooked Ruprecht clusters with ages within 400Myr and 3Gyr
Creators: name: Bonatto, Charles
name: Bica, Eduardo
Publisher: name: arXiv
Year: 2010
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We derive fundamental, structural, and photometric parameters of 15 overlooked Ruprecht (hereafter Ru) star clusters by means of 2MASS photometry and field-star decontamination. Ru\,1, 10, 23, 26, 27, 34, 35, 37, 41, 54, 60, 63, 66, and 152 are located in the third Galactic quadrant, while Ru\,174 is in the first. With the constraints imposed by the field-decontaminated colour-magnitude diagrams (CMDs) and stellar radial density profiles (RDPs), we derive ages in the range 400\,Myr --- 1\,Gyr, except for the older Ru\,37, with $\sim3$\,Gyr. Distances from the Sun are within $\rm1.5\la\ds(kpc)\la8.0$. The RDPs are well-defined and can be described by a King-like profile for most of the radial range, except for Ru\,23, 27, 41, 63, and 174, which present a conspicuous stellar density excess in the central region. The clusters dwell between (or close to) the Perseus and Sagittarius-Carina arms. We derive evidence in favour of cluster size increasing with distance to the Galactic plane ($\zgc$), which is consistent with a low frequency of tidal stress associated with high-$|\zgc|$ regions. The clusters are rather faint even in the near-infrared, with apparent integrated \jj\ magnitudes within $6.4\la m_J\la9.8$, while their absolute magnitudes are $-6.6\la M_J\la-2.6$. Extrapolation of the relation between $M_V$ and $M_J$, derived for globular clusters, suggests that they are low-luminosity optical clusters, with $-5\la M_V\la-1$.
description: The paper contains 11 figures and 3 tables. Accepted by MNRAS.
Signatures of Chaos and Tunneling in AC-Driven Quantum Scattering
Creators: name: Henseler, M.
name: Dittrich, T.
name: Richter, Klaus
Publisher: name: Universität Regensburg
Year: 2000
Subjects: subject: 530 Physik

description: We study classical and quantum scattering in periodically driven mesoscopic electronic devices. The ac-driven square potential well, a prototypical example, is shown to be a chaotic scatterer. Quantum transport in the nonlinear regime of strong driving is investigated in the Floquet framework. In the deep quantum regime, scattering into and out of bound states of an effective potential explains most of the structure in reflection, transmission, and dwell time, controllable via the external driving. For large amplitude and frequency, a single ac-driven quantum well exhibits dynamical tunneling. We identify signatures of the classical phase-space structure in Wigner-function representations of propagated wavepackets.
Non-perturbative predictions for cold atom Bose gases with tunable interactions
Creators: name: Cooper, Fred
name: Chien, Chih-Chun
name: Mihaila, Bogdan
name: Dawson, John F.
name: Timmermans, Eddy
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We derive a theoretical description for dilute Bose gases as a loop expansion in terms of composite-field propagators by rewriting the Lagrangian in terms of auxiliary fields related to the normal and anomalous densities. We demonstrate that already in leading order this non-perturbative approach describes a large interval of coupling-constant values, satisfies Goldstone's theorem, yields a Bose-Einstein transition that is second-order, and is consistent with the critical temperature predicted in the weak-coupling limit by the next-to-leading order large-N expansion.
description: 3 figures
Observing Evolution in the Supergranular Length Scale During Periods of Low Solar Activity
Creators: name: McIntosh, Scott W.
name: Leamon, Robert J.
name: Hock, Rachel A.
name: Rast, Mark P.
name: Ulrich, Roger K.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present the initial results of an observational study into the variation of the dominant length-scale of quiet solar emission: supergranulation. This length-scale reflects the radiative energy in the plasma of the upper solar chromosphere and transition region at the magnetic network boundaries forming as a result of the relentless interaction of magnetic fields and convective motions of the Sun's interior. We demonstrate that a net difference of ~0.5Mm in the supergranular emission length-scale occurs when comparing observations cycle 22/23 and cycle 23/24 minima. This variation in scale is reproduced in the datasets of multiple space- and ground-based instruments and using different diagnostic measures. By means of extension, we consider the variation of the supergranular length-scale over multiple solar minima by analyzing a subset of the Mt Wilson Solar Observatory (MWO) Ca II K image record. The observations and analysis presented provide a tantalizing look at solar activity in the absence of large-scale flux emergence, offering insight into times of "extreme" solar minimum and general behavior such as the phasing and cross-dependence of different components of the spectral irradiance. Given that the modulation of the supergranular scale imprints itself in variations of the Sun's spectral irradiance, as well as in the mass and energy transport into the entire outer atmosphere, this preliminary investigation is an important step in understanding the impact of the quiet sun on the heliospheric system.
description: 6 pages, 5 figures - ApJL. We thank Frank Eparvier, Tom Woods, Stan Solomon, Anna Malanushenko, and Rachel Hauser for useful discussions and help with the text, SOHO, STEREO, and the Canadian Space Agency for making their data publicly available
Youth Public and Political: Young People as (Ir)Relevant Actors in the Realm of Citizenship
Creators: name: Macek, Jakub
name: Macková, Alena
name: Šerek, Jan
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2018
Subjects: M-PSI/05 Psicologia sociale

description: This is the editorial of "Sociální studia / Social Studies" special issue focused on CATCH-EyoU project, funded by the
European Union, Horizon 2020 Programme, Grant Agreement No 649538
Effect of an AC Electric Field on Chaotic Electronic Transport in a Magnetic Superlattice
Creators: name: Yevtushenko, Oleg M.
name: Richter, Klaus
Publisher: name: Universität Regensburg
Year: 1998
Subjects: subject: 530 Physik

description: We study classical transport properties of a two- dimensional electron gas subject to a spatially periodic magnetic field and to a time-dependent (ac) electric field. We investigate the case of a strong one-dimensional magnetic modulation and show how the chaotic electronic motion affects the conductivity of the sample. The dependence of the longitudinal conductivity on the amplitude of the ac field clearly reflects the arising of coupled chaotic phase-space areas as well as features of anomalous diffusion of the charge carriers.
Development of operation strategies for variable speed ball mills
Creators: name: Liu, Sijia
Publisher: name: University of British Columbia
Year: 2018

description: Mineral processing productivity relates to a range of operating parameters, including production rate, product grind size, and energy efficiency. Variations in ore properties and operating conditions change the comminution dynamics, resulting in a constant deviation from operational goals. Although most processing facilities currently use fixed speed grinding mills, variable speed drive is considered to provide an important control variable that can contribute to achieving operational objectives. This thesis examines variable speed ball mill performance under changing operating conditions to recommend operating conditions for the Copper Mountain Mine. JK SimMet, a very powerful predictive tool, was used to estimate grinding circuit performance and mill power consumption. Samples and operating data were collected directly from the Copper Mountain Mine to build a calibrated model. Appearance (breakage distribution) functions of different geo-samples were measured and used to predict plant performance under different ore property variations. The results indicate that higher mill speed and lower ball load operating strategies are preferable with respect to energy savings in variable speed ball mill operations. Ore characteristic variations at the Copper Mountain Mine are significant and can cause large oscillations within mill operations. Thus, ore blending in Copper Mountain should be done carefully and cautiously. However, in combination with traditional optimization methods, ball mill grinding speed can be used to control energy input and offset the influences of ore variability. Optimum ball mill operating conditions can be determined based on circuit design and operating dynamics for any given run-of-mine ore.
Spin and Interaction Effects on Charge Distribution and Currents in One-dimensional Conductors and Rings within the Hartree-Fock Approximation
Creators: name: Cohen, Avraham
name: Richter, Klaus
name: Berkovitz, Richard
Publisher: name: Universität Regensburg
Year: 1998
Subjects: subject: 530 Physik

description: Using the self-consistent Hartree-Fock approximation for electrons with spin at zero temperature, we study the effect of the electronic interactions on the charge distribution in a one- dimensional continuous ring containing a single {\it delta} scatterer. We reestablish that the interaction suppresses the decay of the Friedel oscillations. Based on this result, we show that in an infinite one-dimensional conductor containing a weak scatterer, the current is totally suppressed because of a gap opened at the Fermi energy. In a canonical ensemble of continuous rings containing many scatterers, the interactions enhance the average and the typical persistent current.
Bi(1-x)R(x)FeO(3)(R=rare earth): a family of novel magnetoelectrics
Creators: name: Gabbasova, Z. V.
name: Kuz'min, M. D.
name: Zvezdin, A. K.
name: Dubenko, I. S.
name: Murashov, V. A.
name: Rakov, D. N.
name: Krynetsky, I. B.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Crystals of solid solutions Bi(1-x)R(x)FeO(3),here R= La, Dy, Gd, were obtained with x <=0.7. Solid solutions of the stated rare earths, as x is increased from 0 to 0.7, have one and the same sequence of five crystal structures (rhombohedral C3v 6, triclinic C1 1,orthorhombic D2 6,orthorhombic D2 5, orthorhombic C2v 9). The ferroelectric-paraelectric transition occurs in rhombohedral and triclinic crystals at T=810-560°C.The high temperature modifications are orthorhombic and cubic. The orthorhombic structure C2v 9 holds up to 1180°C.The ferroelectric domain structure was distinguished in all types of crystals. No magnetoelectric effect (MEE) was detected in the orthorhombic crystals with the D2 (222) symmetry class. But the mm2 crystals were found to have both quadratic and linear MEE.The value of the quadratic effect is considerably smaller than that ofthe linear one. Magnetoelectric hysteresis takes place in the crystals. The tensorial properties of the obtained crystals are analyzed from the viewpoint of crystal symmetry.
description: 8 pages, 6 figures
AC transport with reservoirs of finite width
Creators: name: Nöckel, Jens U.
name: Richter, Klaus
Publisher: name: Universität Regensburg
Year: 1997
Subjects: subject: 530 Physik

description: The linear response conductance coefficients are calculated in the scattering approach at finite frequency, damping and magnetic field for a microstructure in which the reservoirs are modeled as quantum wire leads of infinite length but finite width. Independently of frequency, inelastic scattering causes subbands with large group velocity to contribute more strongly to the conductance than channels of comparable transmission but slower propagation. At finite frequency and magnetic fields, additional correction terms appear, some of which are sensitive to the phase of the S matrix.
Weak chaos detection in the Fermi-Pasta-Ulam-$α$ system using $q$-Gaussian statistics
Creators: name: Antonopoulos, Chris G.
name: Christodoulidi, Helen
Publisher: name: arXiv
Year: 2011
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We study numerically statistical distributions of sums of orbit coordinates, viewed as independent random variables in the spirit of the Central Limit Theorem, in weakly chaotic regimes associated with the excitation of the first ($k=1$) and last ($k=N$) linear normal modes of the Fermi-Pasta-Ulam-$α$ system under fixed boundary conditions. We show that at low energies ($E=0.19$), when the $k=1$ linear mode is excited, chaotic diffusion occurs characterized by distributions that are well approximated for long times ($t>10^9$) by a $q$-Gaussian Quasi-Stationary State (QSS) with $q\approx1.4$. On the other hand, when the $k=N$ mode is excited at the same energy, diffusive phenomena are \textit{absent} and the motion is quasi-periodic. In fact, as the energy increases to $E=0.3$, the distributions in the former case pass through \textit{shorter} $q$-Gaussian states and tend rapidly to a Gaussian (i.e. $q\rightarrow 1$) where equipartition sets in, while in the latter we need to reach to E=4 to see a \textit{sudden transition} to Gaussian statistics, without any passage through an intermediate QSS. This may be explained by different energy localization properties and recurrence phenomena in the two cases, supporting the view that when the energy is placed in the first mode weak chaos and "sticky" dynamics lead to a more gradual process of energy sharing, while strong chaos and equipartition appear abruptly when only the last mode is initially excited.
description: 12 pages, 3 figures, submitted for publication to International Journal of Bifurcation and Chaos. In honor of Prof. Tassos Bountis' 60th birthday
Théorie de Lubin-Tate non abélienne l-entière
Creators: name: Dat, Jean-François
Publisher: name: arXiv
Year: 2010
Subjects: subject: Number Theory (math.NT)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics

description: For two distinct primes p and l, we investigate the Z_l-cohomology of the Lubin-Tate towers of a p-adic field. We prove that it realizes some version of Langlands and Jacquet-Langlands correspondences for flat families of irreducible supercuspidal representations parametrized by a Z_l-algebra R, in a way compatible with extension of scalars. When R is a field of characteristic l, this gives a cohomological realization of the Langlands-Vigneras correspondence for supercuspidals, and a new proof of its existence. When R runs over complete local algebras, this provides bijections between deformations of matching mod-l representations. Roughly speaking, we can decompose "the supercuspidal part" of the l-integral cohomology as a direct sum, indexed by irreducible supercuspidals πmod l, of tensor products of universal deformations of πand of its two mates. Besides, we also get a virtual realization of both the semi-simple Langlands-Vigneras correspondence and the l-modular Langlands-Jacquet transfer for all representations, by using the cohomology complex and working in a suitable Grothendieck group.
Combinatorial Hopf Algebras in (Noncommutative) Quantum Field Theory
Creators: name: Tanasa, Adrian
Publisher: name: arXiv
Year: 2010
Subjects: subject: Combinatorics (math.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 05E99, 81T18

description: We briefly review the rôle played by algebraic structures like combinatorial Hopf algebras in the renormalizability of (noncommutative) quantum field theory. After sketching the commutative case, we analyze the noncommutative Grosse-Wulkenhaar model.
description: 15 pages, 6 figures
Semiclassical Approach to Orbital Magnetism of Interacting Diffusive Quantum Systems
Creators: name: Ullmo, Denis
name: Richter, Klaus
name: Baranger, Harold U.
name: Oppen, Felix von
name: Jalabert, Rodolfo A.
Publisher: name: Universität Regensburg
Year: 1997
Subjects: subject: Semiclassical theory; Interacting electrons; Disordered systems; Orbital magnetism
subject: 530 Physik

description: We study interaction effects on the orbital magnetism of diffusive mesoscopic quantum systems. By combining many-body perturbation theory with semiclassical techniques, we show that the interaction contribution to the ensemble-averaged quantum thermodynamic potential can be reduced to an essentially classical operator. We compute the magnetic response of disordered rings and dots for diffusive classical dynamics. Our semiclassical approach reproduces the results of previous diagrammatic quantum calculations.
Study of Thick CZT Detectors for X-ray and Gamma-Ray Astronomy
Creators: name: Li, Qiang
name: Beilicke, M.
name: Lee, Kuen
name: Garson, Alfred
name: Guo, Q.
name: Martin, Jerrad
name: Yin, Y.
name: Dowkontt, P.
name: De Geronimo, G.
name: Jung, I.
name: Krawczynski, H.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: CdZnTe (CZT) is a wide bandgap II-VI semiconductor developed for the spectroscopic detection of X-rays and γ-rays at room temperature. The Swift Burst Alert Telescope is using an 5240 cm2 array of 2 mm thick CZT detectors for the detection of 15-150 keV X-rays from Gamma-Ray Bursts. We report on the systematic tests of thicker (\geq 0.5 cm) CZT detectors with volumes between 2 cm3 and 4 cm3 which are potential detector choices for a number of future X-ray telescopes that operate in the 10 keV to a few MeV energy range. The detectors contacted in our laboratory achieve Full Width Half Maximum energy resolutions of 2.7 keV (4.5%) at 59 keV, 3 keV (2.5%) at 122 keV and 4 keV (0.6%) at 662 keV. The 59 keV and 122 keV energy resolutions are among the world-best results for \geq 0.5 cm thick CZT detectors. We use the data set to study trends of how the energy resolution depends on the detector thickness and on the pixel pitch. Unfortunately, we do not find clear trends, indicating that even for the extremely good energy resolutions reported here, the achievable energy resolutions are largely determined by the properties of individual crystals. Somewhat surprisingly, we achieve the reported results without applying a correction of the anode signals for the depth of the interaction. Measuring the interaction depths thus does not seem to be a pre-requisite for achieving sub-1% energy resolutions at 662 keV.
description: 15 pages, 11 figures
Irreversibility to Reversibility Crossover in Transient Response of an Optically Trapped Particle
Creators: name: Khan, Manas
name: Sood, A. K.
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: We study the transient response of a colloidal bead which is released from different heights and allowed to relax in the potential well of an optical trap. Depending on the initial potential energy, the system's time evolution shows dramatically different behaviors. Starting from the short-time reversible to long-time irreversible transition, a stationary reversible state with zero net dissipation can be achieved as the release point energy is decreased. If the system starts with even lower energy, it progressively extracts useful work from thermal noise and exhibits an anomalous irreversibility. In addition, we have verified the Transient Fluctuation Theorem and the Integrated Transient Fluctuation Theorem even for the non-ergodic descriptions of our system.
description: 6 pages, 4 figures
Weak localization in an ensemble of ballistic cavities filled with antidots arrays
Creators: name: Lütjering, Gerd
name: Richter, Klaus
name: Weiss, Dieter
name: Mao, J.
name: Blick, R.
name: Klitzing, Klaus von
name: Foxon, C.
Publisher: name: Universität Regensburg
Year: 1996
Subjects: subject: Electrical transport; Gallium arsenide; Heterojunctions; Semiconductor-semiconductor heterostructures
subject: 530 Physik

description: We present experimental data on the ballistic weak localisation in square cavities filled with antidot arrays. The weak localisation peak is cusp-like at mK temperatures and clearly deviates from a Lorentzian line shape, which is the theoretical prediction for a classical chaotic system. Although the ideal system, a Sinai billiard, is in principle purely chaotic, directly reflected, non-chaotic trajectories lead to the behaviour of a mixed system in experiment. We demonstrate this by detailed semiclassical analysis. In comparison, empty cavities of equal geometry show a sharper peak in the form of a Lorentzian. Here, imperfections of the experimental structure (boundary roughness, small- angle scattering) seem to change the dynamics of the nominally regular system to chaotic, contrary to the antidot case.
MPEC 2023-X156 : 2023 XO4
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2023 XO4

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Doping dependence of Meissner effect in cuprate superconductors
Creators: name: Feng, Shiping
name: Huang, Zheyu
name: Zhao, Huaisong
Publisher: name: arXiv
Year: 2010
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Within the t-t'-J model, the doping dependence of the Meissner effect in cuprate superconductors is studied based on the kinetic energy driven superconducting mechanism. Following the linear response theory, it is shown that the electromagnetic response consists of two parts, the diamagnetic current and the paramagnetic current, which exactly cancels the diamagnetic term in the normal state, and then the Meissner effect is obtained for all the temperature $T\leq T_{c}$ throughout the superconducting dome. By considering the two-dimensional geometry of cuprate superconductors within the specular reflection model, the main features of the doping and temperature dependence of the local magnetic field profile, the magnetic field penetration depth, and the superfluid density observed on cuprate superconductors are well reproduced. In particular, it is shown that in analogy to the domelike shape of the doping dependent superconducting transition temperature, the maximal superfluid density occurs around the critical doping $δ\approx 0.195$, and then decreases in both lower doped and higher doped regimes.
description: 13 pages, 5 figures
Understanding carsharing patterns for effective TDM policymaking : a study of municipalities in Metro Vancouver
Creators: name: Swett, Arielle
Publisher: name: University of British Columbia
Year: 2018

description: In the context of global climate change and the subsequent need for evolving mobility and smart transit patterns, carsharing (CS) has established itself as a method of individual transportation more sustainable, efficient, and cost-effective than personal automobile ownership. As such, cities worldwide are implementing a variety of policies intended to encourage CS access and utilization with the goal of improving urban planning and human health through transportation demand management (TDM) strategies. Among many potential TDM policies, municipalities have used sticks and carrots to engage developers in TDM through parking requirements and offsets when CS is provided. Many variants of these policies have been implemented throughout Metro Vancouver (MV) municipalities. This thesis provides an overview of the policies adopted by key MV municipalities and establishes a deeper understanding of CS utilization and membership patterns as exhibited through behavioural and policy-driven perspectives. Through two complementary studies, this research 1) identifies and substantiates CS membership and usage patterns as they relate to CS vehicle visibility and proximity to current and prospective members and 2) surveys which policy levers and marketing initiatives present throughout the Metro Vancouver region are effective at incentivizing widespread CS provisioning and use in concurrence with Metro 2040 sustainability goals. Findings were analyzed to formulate a set of best practices guidelines informing thoughtful TDM policymaking for sustainability-focused cities worldwide.
Smooth-disorder Effects in Ballistic Microstructures
Creators: name: Richter, Klaus
name: Ullmo, Denis
name: Jalabert, Rodolfo A.
Publisher: name: Universität Regensburg
Year: 1996
Subjects: subject: 530 Physik

description: We analyze the effect of weak residual disorder in microstructures defined on high-mobility heterojunctions, where the classical electron motion is ballistic. We parameterize the disorder by its correlation length {\it xi} and the elastic mean free path {\it l}, which can be estimated from microscopic models. For the experimentally relevant case in which {\it xi} is not negligible with respect to the size of the microstructure, we present a perturbative semiclassical approach demonstrating that the reduction due to disorder of a two-point Green- function observable, like the average magnetic susceptibility, is intrinsically different from the bulk (power law depending on {\it l} and {\it xi} instead of an exponential damping governed uniquely by {\it l}). The very weak damping that we obtain supports the use of clean (no disorder) models for the ballistic regime. Our analytical findings are confirmed by exact numerical calculations.
Thermal fine structure and magnetic fields in the solar atmosphere: spicules and fibrils
Creators: name: Judge, Philip G.
name: Tritschler, Alexandra
name: Low, Boon Chye
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The relationship between observed structures in the solar atmosphere and the magnetic fields threading them is known only for the solar photosphere, even then imprecisely. We suggest that some of the fine structure in the more tenuous chromosphere and corona- specifically some populations of spicules and fibrils- correspond to warps in 2D sheet-like structures, as an alternative to conventional interpretations in terms of tube-like structures. The sheets are perhaps related to magnetic tangential discontinuities, which Parker has argued arise naturally in low-beta conditions. Some consequences of this suggestion, if it can be confirmed, are discussed.
description: Astrophysical Journal Letters, in press
Orbital Magnetism of Classically Chaotic Quantum Systems
Creators: name: Richter, Klaus
name: Mehlig, Bernhard
Publisher: name: Universität Regensburg
Year: 1998
Subjects: subject: 530 Physik

description: We employ orbital magnetic response functions as a tool to investigate flux-dependent spectral correlations of chaotic quantum dots in the ballistic regime. We compare for the first time results for the persistent current and susceptibility from a semiclassical theory (without adjustable parameters) with accurate quantum-mechanical calculations for the case of an ensemble of chaotic rings threaded by a magnetic flux. We discuss the temperature dependence and suggest this to be a natural and physically relevant parameter in order to study (experimentally) the signature of different semiclassical timescales in smoothed spectral correlation functions.
D4.4: Guidance document for upgrade and  optimization of advanced wastewater treatment
Creators: name: Stapf, Michael
name: Hensel, Tobias
name: Rückbeil, Fiona
name: Sperlich, Alexander
name: Hartmann, Alicia
name: Dietrich, Christian
Publisher: name: Zenodo
Year: 2023

description: Guidance document for upgrade and optimization of advanced wastewater treatment for PROMISCES
Chaos and Interacting Electrons in Ballistic Quantum Dots
Creators: name: Ullmo, Denis
name: Baranger, Harold U.
name: Richter, Klaus
name: Oppen, Felix von
name: Jalabert, Rodolfo A.
Publisher: name: Universität Regensburg
Year: 1998
Subjects: subject: 530 Physik

description: We show that the classical dynamics of independent particles can determine the quantum properties of interacting electrons in the ballistic regime. This connection is established using diagrammatic perturbation theory and semiclassical finite- temperature Green functions. Specifically, the orbital magnetism is greatly enhanced by the combined effects of interactions and finite size. The presence of families of periodic orbits in regular systems makes their susceptibility parametrically larger than that of chaotic systems, a difference which emerges from correlation terms.
First detection of the Methylidyne cation (CH+) fundamental rotational line with the Herschel/SPIRE FTS
Creators: name: Naylor, D. A.
name: Dartois, E.
name: Habart, E.
name: Abergel, A.
name: Baluteau, J. -P.
name: Jones, S. C.
name: Polehampton, E.
name: Ade, P.
name: Anderson, L. D.
name: André, P.
name: Arab, H.
name: Bernard, J. -P.
name: Blagrave, K.
name: Boulanger, F.
name: Cohen, M.
name: Compiègne, M.
name: Cox, P.
name: Davis, G.
name: Emery, R.
name: Fulton, T.
name: Gry, C.
name: Huang, M.
name: Joblin, C.
name: Kirk, J. M.
name: Lagache, G.
name: Lim, T.
name: Madden, S.
name: Makiwa, G.
name: Martin, P.
name: Miville-Deschênes, M. -A.
name: Molinari, S.
name: Moseley, H.
name: Motte, F.
name: Okumura, K.
name: Pinheiro-Gocalvez, D.
name: Rodón, J. A.
name: Russeil, D.
name: Saraceno, P.
name: Sidher, S.
name: Spencer, L.
name: Swinyard, B.
name: Ward-Thompson, D.
name: White, G. J.
name: Zavagno, A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Aims. To follow the species chemistry arising in diverse sources of the Galaxy with Herschel. Methods. SPIRE FTS sparse sampled maps of the Orion bar & compact HII regions G29.96-0.02 and G32.80+0.19 have been analyzed. Results. Beyond the wealth of atomic and molecular lines detected in the high-resolution spectra obtained with the FTS of SPIRE in the Orion Bar, one emission line is found to lie at the position of the fundamental rotational transition of CH+ as measured precisely in the laboratory (Pearson & Drouion 2006). This coincidence suggests that it is the first detection of the fundamental rotational transition of CH+. This claim is strengthened by the observation of the lambda doublet transitions arising from its relative, CH, which are also observed in the same spectrum. The broad spectral coverage of the SPIRE FTS allows for the simultaneous measurement of these closely related chemically species, under the same observing conditions. The importance of these lines are discussed and a comparison with results obtained from models of the Photon Dominated Region (PDR) of Orion are presented. The CH+ line also appears in absorption in the spectra of the two galactic compact HII regions G29.96-0.02 and G32.80+0.19, which is likely due to the presence of CH+ in the the Cold Neutral Medium of the galactic plane. These detections will shed light on the formation processes and on the existence of CH+, which are still outstanding questions in astrophysics.
description: Accepted for publication in the A&A Herschel first results Special Issue
Semiclassical Linear Response: Far-Infrared Absorption for Ballistic Quantum Systems
Creators: name: Mehlig, Bernhard
name: Richter, Klaus
Publisher: name: Universität Regensburg
Year: 1998
Subjects: subject: 530 Physik

description: We derive a general semiclassical theory for linear response functions at finite temperatures and finite frequencies for quantum systems with internal ballistic dynamics. As a specific example, we present a detailed quantum mechanical and semiclassical analysis of the infrared absorption in small two-dimensional conducting disks. We incorporate the effect of Coulomb interactions into our semiclassical approach using a Thomas-Fermi approximation, which is valid for low external frequencies. Our semiclassical results are in excellent agreement with corresponding quantum calculations.