cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A direct experimental limit on neutron -- mirror neutron oscillations
Creators: name: Ban, G.
name: Bodek, K.
name: Daum, M.
name: Henneck, R.
name: Heule, S.
name: Kasprzak, M.
name: Khomutov, N.
name: Kirch, K.
name: Kistryn, S.
name: Knecht, A.
name: Knowles, P.
name: Kuzniak, M.
name: Lefort, T.
name: Mtchedlishvili, A.
name: Naviliat-Cuncic, O.
name: Plonka, C.
name: Quemener, G.
name: Rebetez, M.
name: Rebreyend, D.
name: Roccia, S.
name: Rogel, G.
name: Tur, M.
name: Weis, A.
name: Zejma, J.
name: Zsigmond, G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: In case a mirror world with a copy of our ordinary particle spectrum would exist, the neutron n and its degenerate partner, the mirror neutron ${\rm n'}$, could potentially mix and undergo ${\rm nn'}$ oscillations. The interaction of an ordinary magnetic field with the ordinary neutron would lift the degeneracy between the mirror partners, diminish the ${\rm n'}$-amplitude in the n-wavefunction and, thus, suppress its observability. We report an experimental comparison of ultracold neutron storage in a trap with and without superimposed magnetic field. No influence of the magnetic field is found and, assuming negligible mirror magnetic fields, a limit on the oscillation time $τ_{\rm nn'} > 103$ s (95% C.L.) is derived.
description: 4 pages, 1 figure. accepted for publication in Phys. Rev. Lett
16442-144814485050-1-SM.pdf
Creators: name: Morocho, Alicia
Publisher: name: figshare
Year: 2021
Subjects: subject: 111502 Clinical Pharmacology and Therapeutics
subject: FOS: Clinical medicine

description: Objetivo: Caracterizar epidemiológicamente las fracturas expuestas y las complicaciones infecciosas en pacientes atendidos en el servicio de emergencia de Traumatología del Hospital Teodoro Maldonado Carbo de la ciudad de Guaya-quil, Ecuador. Método: Se realizó un estudio descriptivo, retrospectivo, me-diante un análisis del sistema de registro del Teodoro Mal-donado Carbo incluyéndose pacientes con diagnóstico de fracturas expuestas durante el período 2015-2017. Resultados: Se incluyeron 438 pacientes, con predominio en hombres (75,1%; n=329) y jóvenes <35 años 61% (n=267), la región tibial fue la zona corporal más afectada (62,3%; n=273). En cuanto a la severidad del grado de exposición, la fractura tipo IIIB fue la más frecuente 36,1% (n=158), siendo la fijación externa el procedimiento más empleado (57,8%; n = 253). El 39,7% (n = 174) de las fracturas se infectó y el sta-phylococcus aureus fue el agente más común con 40,8% (n = 71). Conclusiones: La frecuencia de casos de fracturas expues-tas en el Hospital Teodoro Maldonado Carbo de la ciudad de Guayaquil es alta en comparación con otros estudios, con un predominio en hombres, en sujetos jóvenes y con afectación tibial. Asimismo, se observa una alta frecuencia de infección en la fracturas, siendo el staphylococcus aureus el principal microorganismos aislados
Cyclotron resonance photoconductivity of a two-dimensional electron gas in HgTe quantum wells
Creators: name: Kvon, Ze-Don
name: Danilov, Sergey N.
name: Mikhailov, Nikolay N.
name: Dvoretsky, Sergey A.
name: Prettl, Wilhelm
name: Ganichev, Sergey D.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Far-infrared cyclotron resonance photoconductivity (CRP) is investigated in HgTe quantum wells (QWs) of various widths grown on (013) oriented GaAs substrates. It is shown that CRP is caused by the heating of two-dimensional electron gas (2DEG). From the resonance magnetic field strength effective masses and their dependence on the carrier concentration is obtained. We found that the effective mass in each sample slightly increases from the value (0.0260 \pm 0.0005)m_0 at N_s = 2.2x10^11 cm^(-2) to (0.0335 \pm 0.0005)m_0 at N_s = 9.6x10^11 cm^(-2). Compared to determination of effective masses by the temperature dependence of magnitudes of the Shubnikov-de Haas (SdH) oscillations used so far in this material our measurements demonstrate that the CRP provides a more accurate (about few percents) tool. Combining optical methods with transport measurements we found that the transport time substantially exceeds the cyclotron resonance lifetime as well as the quantum lifetime which is the shortest.
description: 3 pages, 2 figures
Selective reactions of 14-membered macrolides-a conformational approach using MM2 calculation
Creators: name: Neeland, Edward George
Publisher: name: University of British Columbia
Year: 2010

description: A number of 14-membered lactones, derived from 42 or 43 were used to investigate a series of alkylation, hydride reduction and hydrogenation reactions. These reactions yielded diastereoselective product distributions which were rationalized as proceeding through a [3434] conformation. A simple model for determining these low energy conformations was developed using MM2 calculations, energy trends of acyclic molecules, X-ray crystallography and NMR spectroscopy. In order to unambiguously identify ring conformations, a method to generate polar maps of the large ring lactones was developed. These polar maps quickly differentiated complex ring conformations as well as identifying the symmetry elements of a conformation. With the aid of polar maps, a new solid state conformation for 14-membered rings was discovered for two macrolides synthesized in this project. Furthermore, three additional unidentified examples of this conformation were recognized from the literature. Energy calculations showed this twisted conformation to be of very low energy. The discovery of the twist conformation led to an improved nomenclature for large rings which considers the number of bonds separating both corner and pseudo corner atoms. Under this proposed nomenclature, the twist conformation was designated the [34'3'4'] conformation. During this investigation, a useful technique for assigning the stereochemistry of E and Z-trimethylsilyl (TMS) enol ethers was developed using ¹H NMR nuclear Overhauser effect difference spectroscopy (NOEDS) experiments. One advantage of this technique over the widely used ¹³C NMR method is that only one isomer is required to accurately assign the Eor Z. stereochemistry. [Formula Omitted]
Universal parametric correlations in the classical limit of quantum transport
Creators: name: Brouwer, Piet W.
name: Rahav, Saar
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Quantum corrections to transport through a chaotic ballistic cavity are known to be universal. The universality not only applies to the magnitude of quantum corrections, but also to their dependence on external parameters, such as the Fermi energy or an applied magnetic field. Here we consider such parameter dependence of quantum transport in a ballistic chaotic cavity in the semiclassical limit obtained by sending Planck's constant to zero without changing the classical dynamics of the open cavity. In this limit quantum corrections are shown to have a universal parametric dependence which is not described by random matrix theory.
description: 4 pages, 2 figures
Link-space formalism for network analysis
Creators: name: Smith, David M. D.
name: Lee, Chiu Fan
name: Onnela, Jukka-Pekka
name: Johnson, Neil F.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: We introduce the link-space formalism for analyzing network models with degree-degree correlations. The formalism is based on a statistical description of the fraction of links l_{i,j} connecting nodes of degrees i and j. To demonstrate its use, we apply the framework to some pedagogical network models, namely, random-attachment, Barabasi-Albert preferential attachment and the classical Erdos and Renyi random graph. For these three models the link-space matrix can be solved analytically. We apply the formalism to a simple one-parameter growing network model whose numerical solution exemplifies the effect of degree-degree correlations for the resulting degree distribution. We also employ the formalism to derive the degree distributions of two very simple network decay models, more specifically, that of random link deletion and random node deletion. The formalism allows detailed analysis of the correlations within networks and we also employ it to derive the form of a perfectly non-assortative network for arbitrary degree distribution.
description: This updated version has been expanded to include a number of new results. 19 pages, 11 figures. Minor Typos corrected
Likelihood based inference for monotone response models
Creators: name: Banerjee, Moulinath
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 62G20, 62E20, 62G08 (Primary)

description: The behavior of maximum likelihood estimates (MLEs) and the likelihood ratio statistic in a family of problems involving pointwise nonparametric estimation of a monotone function is studied. This class of problems differs radically from the usual parametric or semiparametric situations in that the MLE of the monotone function at a point converges to the truth at rate $n^{1/3}$ (slower than the usual $\sqrt{n}$ rate) with a non-Gaussian limit distribution. A framework for likelihood based estimation of monotone functions is developed and limit theorems describing the behavior of the MLEs and the likelihood ratio statistic are established. In particular, the likelihood ratio statistic is found to be asymptotically pivotal with a limit distribution that is no longer $χ^2$ but can be explicitly characterized in terms of a functional of Brownian motion. Applications of the main results are presented and potential extensions discussed.
description: Published at http://dx.doi.org/10.1214/009053606000001578 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Counting statistics for the Anderson impurity model: Bethe ansatz and Fermi liquid study
Creators: name: Gogolin, A. O.
name: Konik, R. M.
name: Ludwig, A. W. W.
name: Saleur, H.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We study the counting statistics of charge transport in the Anderson impurity model (AIM) employing both Keldysh perturbation theory in a Fermi liquid picture and the Bethe ansatz. In the Fermi liquid approach, the object of our principal interest is the generating function for the cumulants of the charge current distribution. We derive an exact analytic formula relating the full counting statistic (FCS) generating function to the self-energy of the system in the presence of a measuring field. We first check that our approach reproduces correctly known results in simple limits, like the FCS of the resonant level system (AIM without Coulomb interaction). We then proceed to study the FCS for the AIM perturbatively in the Coulomb interaction. By comparing this perturbative analysis with a strong coupling expansion, we arrive at a conjecture for an expression for the FCS generating function at O(V^3) (V is the voltage across the impurity) valid at all orders in the interaction. In the second part of the article, we examine a Bethe ansatz analysis of the current noise for the AIM. Unlike the Fermi liquid approach, here the goal is to obtain qualitative, not quantitative, results for a wider range of voltages both in and out of a magnetic field. Particularly notable are finite field results showing a double peaked structure in the current noise for voltages satisfying eV ~ mu H$. This double peaked structure is the ``smoking gun'' of Kondo physics in the current noise and is directly analogous to the single peak structure predicted for the differential conductance of the AIM.
description: 39 pages, 5 figures
Walking on fractals: diffusion and self-avoiding walks on percolation clusters
Creators: name: Blavatska, Viktoria
name: Janke, Wolfhard
Publisher: name: arXiv
Year: 2008
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We consider random walks (RWs) and self-avoiding walks (SAWs) on disordered lattices directly at the percolation threshold. Applying numerical simulations, we study the scaling behavior of the models on the incipient percolation cluster in space dimensions d=2, 3, 4. Our analysis yields estimates of universal exponents, governing the scaling laws for configurational properties of RWs and SAWs.
description: 21 pages
Anti-symplectic involutions for Lagrangian spheres in a symplectic quadric surface
Creators: name: Kim, Joontae
name: Moon, Jiyeon
Publisher: name: arXiv
Year: 2021
Subjects: subject: Symplectic Geometry (math.SG)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 53D12, 55M35, 32Q65

description: We show that the space of anti-symplectic involutions of a monotone $S^2\times S^2$ whose fixed points set is a Lagrangian sphere is connected. This follows from a stronger result, namely that any two anti-symplectic involutions in that space are Hamiltonian isotopic.
description: 8 pages, 1 figure
Random logic networks: from classical Boolean to quantum dynamics
Creators: name: Kluge, Lucas
name: Socolar, Joshua E. S.
name: Schöll, Eckehard
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate dynamical properties of a quantum generalization of classical reversible Boolean networks. The state of each node is encoded as a single qubit, and classical Boolean logic operations are supplemented by controlled bit-flip and Hadamard operations. We consider synchronous updating schemes in which each qubit is updated at each step based on stored values of the qubits from the previous step. We investigate the periodic or quasiperiodic behavior of quantum networks, and we analyze the propagation of single site perturbations through the quantum networks with input degree one. A non-classical mechanism for perturbation propagation leads to substantially different evolution of the Hamming distance between the original and perturbed states.
description: 11 pages, 8 figures; revised for Physical Review E
A Massive Yang-Mills Theory based on the Nonlinearly Realized Gauge Group
Creators: name: Bettinelli, Daniele
name: Ferrari, Ruggero
name: Quadri, Andrea
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We propose a subtraction scheme for a massive Yang-Mills theory realized via a nonlinear representation of the gauge group (here SU(2)). It is based on the subtraction of the poles in D-4 of the amplitudes, in dimensional regularization, after a suitable normalization has been performed. Perturbation theory is in the number of loops and the procedure is stable under iterative subtraction of the poles. The unphysical Goldstone bosons, the Faddeev-Popov ghosts and the unphysical mode of the gauge field are expected to cancel out in the unitarity equation. The spontaneous symmetry breaking parameter is not a physical variable. We use the tools already tested in the nonlinear sigma model: hierarchy in the number of Goldstone boson legs and weak power-counting property (finite number of independent divergent amplitudes at each order). It is intriguing that the model is naturally based on the symmetry SU(2)_L local times SU(2)_R global. By construction the physical amplitudes depend on the mass and on the self-coupling constant of the gauge particle and moreover on the scale parameter of the radiative corrections. The Feynman rules are in the Landau gauge.
description: 44 pages, 1 figure, minor changes, final version accepted by Phys. Rev. D
The S2N2 metallicity calibrator and the abundance gradient of M 33
Creators: name: Viironen, K.
name: Delgado-Inglada, G.
name: Mampaso, A.
name: Magrini, L.
name: Corradi, R. L. M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We introduce the log(Ha/[SII]6717+6731) vs. log(Ha/[NII]6583) (S2N2) diagnostic diagram as metallicity and ionisation parameter indicator for HII regions in external galaxies. The location of HII regions in the S2N2 diagram was studied both empirically and theoretically. We found that, for a wide range of metallicities, the S2N2 diagram gives single valued results in the metallicity-ionisation parameter plane. We demonstrate that the S2N2 diagram is a powerful tool to estimate metallicities of high-redshift (z ~ 2) HII galaxies. Finally, we derive the metallicity for 76 HII regions in M33 from the S2N2 diagram and calculate an O/H abundance gradient for this galaxy of -0.05 (+-0.01) dex kpc^-1.
description: 10 pages, 3 figures and 2 tables. Accepted for publication in MNRAS
DWELLING: A PERSPECTIVE OF THE IN-BETWEEN
Creators: name: Carlson, Stacey
Publisher: name: Digital Repository at the University of Maryland
Year: 2019
Subjects: subject: Dance
subject: Performing arts
subject: circus
subject: dance
subject: dwelling
subject: perception
subject: physical theater
subject: puppetry

description: Today’s contemporary circus is marked by a merging of embodied practices, including dance, puppetry and clowning. Apart from etymological play on meaning and the corporeal; the mixing, meddling, and swirling of genres not only offers the artist a new way to express sensory experiences, but also engages the artist and the art into a new interdependent relationship with an interactive audience. This research explores how these traditional and contemporary art forms are being interpreted, understood and contextualized. Through a tacit use of phenomenology, the study contributes to a better understanding of the location of embodied practice in dance research and it establishes the interconnectedness between tradition and modernity; past, present, and future; and the exploration of the in-between. Dwelling was an interdisciplinary work performed October 12 and 14, 2018 in the Kogod Theater at the Clarice Performing Arts Center in partial fulfillment of the Master in Fine Arts degree from the University of Maryland, College Park’s School of Theater, Dance, and Performance Studies.
Chiral valley phonons and flat phonon bands in moiré materials
Creators: name: Maity, Indrajit
name: Mostofi, Arash A.
name: Lischner, Johannes
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We investigate the chirality of phonon modes in twisted bilayer WSe2 and demonstrate distinct chiral behavior of the $K/K^\prime$ valley phonons for twist angles close to $0^{\circ}$ and close to $60^{\circ}$. In particular, multiple chiral non-degenerate $K/K^\prime$ valley phonons are found for twist angles near $60^{\circ}$ whereas no non-degenerate chiral modes are found for twist angles close to $0^\circ$. Moreover, we discover two sets of emergent chiral valley modes that originate from an inversion symmetry breaking at the moiré scale and find similar modes in moiré patterns of strain-engineered bilayers WSe2 and MoSe2/WSe2 heterostructures. At the energy gap between acoustic and optical modes, the formation of flat phonon bands for a broad range of twist angles is observed in the twisted bilayer WSe2. Our findings are relevant for understanding electron-phonon and exciton-phonon scattering in moiré materials and also for the design of phononic analogues of flat band electrons.
description: Accepted as a Letter in Phys. Rev. B
1. Design and synthesis of new chiral units for potentially ferroelectric liquid crystals : liquid crystals containing a thiiran unit. 2. Heterogeneous catalysis of the racemization of 1,1'-binaphthyl by titanium dioxide powder
Creators: name: Wang, Xin
Publisher: name: University of British Columbia
Year: 2010

description: New liquid crystals have been synthesized and their transition phases have been studied. It was found that a family of (-)-2-methyl 2R,3S-epithio-4'-alkoxybiphenyl pentanoates are liquid crystals but a similar system of ( + )-2-methyl 2S,3R-epoxy-4'-alkoxybiphenyl pentanoates are not. Of the liquid crystals, MEAOBP-S-7 exhibits smectic A and B phases; MEAOBP-S-8 and MEAOBP-S-9 show only the smectic B phases; MEAOBP-S-10 shows a monotropic chiral smectic C phase. This distinction is in agreement with the argument that the internal dipolar interaction of the molecule plays an important role in determining liquid crystalline behaviour of this ester system. The reaction rate of the racemization of optically active binaphthyl can be moderately increased in the presence of finely divided titanium dioxide (anatase) powder. This first order catalyzed reaction has a proportional relationship with the concentrations of both the catalyst and the binaphthyl. The catalyzed reaction can be poisoned permanently by the addition of polynuclear aromatic compounds and the poisoning efficiency is dependent of the number of the aromatic rings the poison posesses. By comparison with the catalyzed racemizations of binaphthyl by platinum, nickel and carbon and from the kinetic and mechanistic studies on the titanium dioxide catalyzed racemization, we conclude that (1) this catalytic phenomenon is common among heterogeneous inorganic solids and can be extended to other simple reactions, and that (2) the mechanism of the catalysis probably involves a radical anion intermediate.
Robust Machine Learning Applied to Astronomical Datasets III: Probabilistic Photometric Redshifts for Galaxies and Quasars in the SDSS and GALEX
Creators: name: Ball, Nicholas M.
name: Brunner, Robert J.
name: Myers, Adam D.
name: Strand, Natalie E.
name: Alberts, Stacey L.
name: Tcheng, David
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We apply machine learning in the form of a nearest neighbor instance-based algorithm (NN) to generate full photometric redshift probability density functions (PDFs) for objects in the Fifth Data Release of the Sloan Digital Sky Survey (SDSS DR5). We use a conceptually simple but novel application of NN to generate the PDFs - perturbing the object colors by their measurement error - and using the resulting instances of nearest neighbor distributions to generate numerous individual redshifts. When the redshifts are compared to existing SDSS spectroscopic data, we find that the mean value of each PDF has a dispersion between the photometric and spectroscopic redshift consistent with other machine learning techniques, being sigma = 0.0207 +/- 0.0001 for main sample galaxies to r < 17.77 mag, sigma = 0.0243 +/- 0.0002 for luminous red galaxies to r < ~19.2 mag, and sigma = 0.343 +/- 0.005 for quasars to i < 20.3 mag. The PDFs allow the selection of subsets with improved statistics. For quasars, the improvement is dramatic: for those with a single peak in their probability distribution, the dispersion is reduced from 0.343 to sigma = 0.117 +/- 0.010, and the photometric redshift is within 0.3 of the spectroscopic redshift for 99.3 +/- 0.1% of the objects. Thus, for this optical quasar sample, we can virtually eliminate 'catastrophic' photometric redshift estimates. In addition to the SDSS sample, we incorporate ultraviolet photometry from the Third Data Release of the Galaxy Evolution Explorer All-Sky Imaging Survey (GALEX AIS GR3) to create PDFs for objects seen in both surveys. For quasars, the increased coverage of the observed frame UV of the SED results in significant improvement over the full SDSS sample, with sigma = 0.234 +/- 0.010. We demonstrate that this improvement is genuine. [Abridged]
description: Accepted to ApJ, 10 pages, 12 figures, uses emulateapj.cls
Localization and chiral symmetry in 2+1 flavor domain wall QCD
Creators: name: Antonio, David J.
name: Bowler, Kenneth C.
name: Boyle, Peter A.
name: Christ, Norman H.
name: Clark, Michael A.
name: Cohen, Saul D.
name: Dawson, Chris
name: Hart, Alistair
name: Joó, Balint
name: Jung, Chulwoo
name: Kenway, Richard D.
name: Li, Shu
name: Lin, Meifeng
name: Mawhinney, Robert D.
name: Maynard, Christopher M.
name: Ohta, Shigemi
name: Tweedie, Robert J.
name: Yamaguchi, Azusa
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We present results for the dependence of the residual mass of domain wall fermions (DWF) on the size of the fifth dimension and its relation to the density and localization properties of low-lying eigenvectors of the corresponding hermitian Wilson Dirac operator relevant to simulations of 2+1 flavor domain wall QCD. Using the DBW2 and Iwasaki gauge actions, we generate ensembles of configurations with a $16^3\times 32$ space-time volume and an extent of 8 in the fifth dimension for the sea quarks. We demonstrate the existence of a regime where the degree of locality, the size of chiral symmetry breaking and the rate of topology change can be acceptable for inverse lattice spacings $a^{-1} \ge 1.6$ GeV.
description: 59 Pages, 23 figures, 1 MPG linked
The Sole Measure of Service: A Social History of Baltimore's Public Libraries During World War II
Creators: name: Coddington, Gwenlyn
Publisher: name: Digital Repository at the University of Maryland
Year: 2019
Subjects: subject: American history
subject: Library science
subject: Baltimore
subject: Maryland
subject: Public Libraries
subject: World War II

description: This thesis examines the history of public libraries in Baltimore and Maryland during World War II. Drawing from contemporary newspapers and institutional records, it argues that World War II expanded institutional opportunities for public libraries while exposing their limitations as agents of social change. Concentrating on how Baltimore’s libraries successfully contributed to and enabled the war’s information economy undercuts the narrative of libraries’ impotency as information centers during this period by locating their validation among the communities they served, rather than their relationship with the state or their postwar status. However, even as the war enabled this transformation, it simultaneously exposed the limits of libraries’ social ideology, destabilizing their position as institutions of social progressivism. Analyzing gender discrimination within librarianship and the experiences of African American Marylanders as users and library professionals demonstrates the limited vision Baltimore’s librarians held for enacting meaningful change within their institutions and communities.
Computational Aeroacoustics of Various Propeller Designs for eVTOL Applications
Creators: name: Passe, Bernadine
Publisher: name: Digital Repository at the University of Maryland
Year: 2019
Subjects: subject: Aerospace engineering

description: An in-house CFD solver, GPU-Accelerated Rotorcraft Flow-Field (GARFIELD), was coupled to an acoustic code for a computational aeroacoustic framework to an- alyze low aspect ratio propellers in hover such as those found on typical eVTOL aircraft. Various design parameters including twist, planform, number of blades, RPM, sweep, and disk loading were varied to evaluate their effect on aerodynamic performance as well as the overall average sound pressure level (OASPL) experienced by an observer. A nearby boom geometry was added to investigate the impact of the unsteady airloads on the aeroacoustic performance. Aerodynamic loads were also calculated by a BEMT analysis for comparison to the results predicted by CFD in GARFIELD. The main drivers to reduce the OASPL were found to be RPM and blade count. It was found that the boom geometry and all other design parameters for the propellers did not have a significant impact on the aeroacoustic performance.
THE EFFECT OF OWN RACE/ETHNICITY DENSITY ON INSURANCE TAKE-UP BY ASIAN AMERICANS
Creators: name: Choi, Yoon Sun
Publisher: name: Digital Repository at the University of Maryland
Year: 2019
Subjects: subject: Public health
subject: Asian Americans
subject: Health Insurance
subject: Minority Health

description: Asian Americans are the fastest growing minority population in the U.S. (Lopez et al., 2017). Since the implementation of the Patient Protection and Affordable Care Act (ACA), Asian Americans have benefitted from insurance coverage increases but continue to experience disparities at the subgroup level (Park et al., 2018). This study investigates the association of own race subgroup density on the take-up of insurance by examining the effect of Asian subgroup concentration that may provide social and knowledge support linkages to available insurance coverage options.
No Place for a Girl? Women as Sports Reporters from the Gilded Age to the Roaring Twenties
Creators: name: Siqueira Paranhos Velloso, Carolina
Publisher: name: Digital Repository at the University of Maryland
Year: 2019
Subjects: subject: Journalism
subject: History
subject: Media
subject: Newspapers
subject: Reporter
subject: Sports
subject: Women

description: This thesis examines some of the first women to write about sports for print media from 1870 to 1920. It also explains the social, economic and cultural circumstances from which early women sports journalists emerged. The thesis discusses the evolution of reporting as a profession and shows that the birth of this new occupation increased opportunities for women in the newspaper industry; demonstrates how the rise of organized sports, and changing attitudes towards them, affected women’s ability to participate in, be fans of, and write about sports; and introduces three women sportswriters of the late nineteenth and early twentieth centuries – Maria Morgan, Ella Black and Ina Eloise Young – as well as explains the different strategies and mechanisms they used in order to achieve success in a male-dominated field where their presence was very much contested.
Feynman parametrization and Mellin summation at finite temperature
Creators: name: Ayala, Alejandro
name: Piccinelli, Gabriella
name: Sanchez, Angel
name: Tejeda-Yeomans, Maria Elena
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We show that the Mellin summation technique (MST) is a well defined and useful tool to compute loop integrals at finite temperature in the imaginary-time formulation of thermal field theory, especially when interested in the infrared limit of such integrals. The method makes use of the Feynman parametrization which has been claimed to have problems when the analytical continuation from discrete to arbitrary complex values of the Matsubara frequency is performed. We show that without the use of the MST, such problems are not intrinsic to the Feynman parametrization but instead, they arise as a result of (a) not implementing the periodicity brought about by the possible values taken by the discrete Matsubara frequencies before the analytical continuation is made and (b) to the changing of the original domain of the Feynman parameter integration, which seemingly simplifies the expression but in practice introduces a spurious endpoint singularity. Using the MST, there are no problems related to the implementation of the periodicity but instead, care has to be taken when the sum of denominators of the original amplitude vanishes. We apply the method to the computation of loop integrals appearing when the effects of external weak magnetic fields on the propagation of scalar particles is considered.
description: 16 pages, 1 figure. Discussion expanded. References added. Published version
Coulomb Gas on the Keldysh Contour: Anderson-Yuval-Hamann representation of the Nonequilibrium Two Level System
Creators: name: Mitra, Aditi
name: Millis, Andrew J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The nonequilibrium tunnelling center model of a localized electronic level coupled to a fluctuating two-state system and to two electronic reservoirs, is solved via an Anderson-Yuval-Hamann mapping onto a plasma of alternating positive and negative charges time-ordered along the two "Keldysh" contours needed to describe nonequilibrium physics. The interaction between charges depends both on whether their time separation is small or large compared to a dephasing scale defined in terms of the chemical potential difference between the electronic reservoirs and on whether their time separation is larger or smaller than a decoherence scale defined in terms of the current flowing from one reservoir to another. A renormalization group transformation appropriate to the nonequilibrium problem is defined. An important feature is the presence in the model of a new coupling, essentially the decoherence rate, which acquires an additive renormalization similar to that of the energy in equilibrium problems. The method is used to study interplay between the dephasing-induced formation of independent resonances tied to the two chemical potentials and the decoherence which cuts off the scaling and leads to effectively classical long-time behavior. We determine the effect of departures from equilibrium on the localization-delocalization phase transition.
description: discussion and references added, to appear in PRB
Spin dynamics of the quantum dipolar magnet Yb$_3$Ga$_5$O$_{12}$ in an external field
Creators: name: Lhotel, E.
name: Mangin-Thro, L.
name: Ressouche, E.
name: Steffens, P.
name: Bichaud, E.
name: Knebel, G.
name: Brison, J. -P.
name: Marin, C.
name: Raymond, S.
name: Zhitomirsky, M. E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We investigate ytterbium gallium garnet Yb$_{3}$Ga$_{5}$O$_{12}$ in the paramagnetic phase above the supposed magnetic transition at $T_λ \approx 54$ mK. Our study combines susceptibility and specific heat measurements with neutron scattering experiments and theoretical calculations. Below 500 mK, the elastic neutron response is strongly peaked in the momentum space. Along with that the inelastic spectrum develops flat excitation modes. In magnetic field, the lowest energy branch follows a Zeeman shift in accordance with the field-dependent specific heat data. An intermediate state with spin canting away from the field direction is evidenced in small magnetic fields. In the field of 2 T, the total magnetization almost saturates and the measured excitation spectrum is well reproduced by the spin-wave calculations taking into account solely the dipole-dipole interactions. The small positive Curie-Weiss temperature derived from the susceptibility measurements is also accounted for by the dipole spin model. Altogether, our results suggest that Yb$_{3}$Ga$_{5}$O$_{12}$ is a quantum dipolar magnet.
description: 12 pages, 10 figures
The Phase Structure of Higher-Dimensional Black Rings and Black Holes
Creators: name: Emparan, Roberto
name: Harmark, Troels
name: Niarchos, Vasilis
name: Obers, Niels A.
name: Rodriguez, Maria J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We construct an approximate solution for an asymptotically flat, neutral, thin rotating black ring in any dimension D>=5 by matching the near-horizon solution for a bent boosted black string, to a linearized gravity solution away from the horizon. The rotating black ring solution has a regular horizon of topology S^1 x S^{D-3} and incorporates the balancing condition of the ring as a zero-tension condition. For D=5 our method reproduces the thin ring limit of the exact black ring solution. For D>=6 we show that the black ring has a higher entropy than the Myers-Perry black hole in the ultra-spinning regime. By exploiting the correspondence between ultra-spinning black holes and black membranes on a two-torus, we take steps towards qualitatively completing the phase diagram of rotating blackfolds with a single angular momentum. We are led to propose a connection between MP black holes and black rings, and between MP black holes and black Saturns, through merger transitions involving two kinds of `pinched' black holes. More generally, the analogy suggests an infinite number of pinched black holes of spherical topology leading to a complicated pattern of connections and mergers between phases.
description: 61 pages, 6 figures, latex. v2: Added refs., typos corrected, improved section 8. v3: minor changes, version appearing in JHEP
I controventi concentrici ad X nelle strutture metalliche: Progettazione, modellazione e analisi strutturale
Creators: name: Toreno, Maurizio
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2013

description: Il presente lavoro di tesi ha come principale obiettivo quello di analizzare e successivamente valutare gli effetti dell’applicazione del “capacity design” (attuale filosofia progettuale antisismica delle strutture) ai controventi concentrici ad X (XCBF). Sulla base delle criticità emerse dall’analisi delle indicazioni normative contenute nella norma europea UNI EN 1998 – “Eurocodice 8 - Progettazione delle strutture per la resistenza sismica” (EC8) è stata sviluppata una metodologia progettuale alternativa (di seguito chiamata Approccio proposto P.A.), che, pur modificando lievemente alcune prescrizioni progettuali imposte dall’EC8, ovvero le limitazioni sui valori della snellezza adimensionale delle diagonali e del fattore di sovraresistenza delle diagonali, preserva le caratteristiche di resistenza e duttilità derivanti dall’ applicazione delle regole del “capacity design”.
Al fine di valutare le prestazioni sismiche delle strutture progettate secondo l’approccio proposto (P.A.) e confrontarle con quelle ottenibili con l’applicazione dell’EC8, sono stati esaminati 450 differenti casi di studio ottenuti mediante variazione parametrica di: maglia strutturale, numero di piani, numero di controventi disposti in pianta, tipologie di sezioni, caratteristiche meccaniche dell’acciaio. Il comportamento sismico di tutte le strutture così progettate (sia approccio EC8 che P.A.) è stato esaminato in campo non lineare mediante analisi statiche e dinamiche.
I risultati di tale confronto, espressi mediante diversi parametri di prestazione strutturale, quali peso, fattori di sovraresistenza, sovraresistenza globale, domanda/capacità di duttilità locale e globale, dimostrano che l’approccio proposto consente: (a) di ridurre la sovraresistenza globale non necessaria derivante dall’applicazione del capacity design secondo l’EC8; (b) di conseguire una ottimizzazione della progettazione strutturale; (c) di assicurare una buona duttilità locale e globale del controvento; (d) di avere una maggiore “flessibilità” nella progettazione.
Infine, i risultati progettuali ottenuti applicando la procedura proposta ed il capacity design secondo l’ EC8 sono stati confrontati, da un punto di vista prestazionale ed economico, con i risultati ottenuti sostituendo ai tradizionali controventi ad X dispositivi ad instabilità impedita (BRB). Le soluzioni con BRB, da un punto di vista prestazionale, consentono maggiori capacità dissipative (plasticizzazione pressoché contemporanea dei controventi) e, da un punto di vista economico, portano a risultati paragonabili all’uso di controventi tradizionali.
La versione greca della IV Ecloga di Virgilio e il commento di Costantino
Creators: name: Giardino, Melania
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2013

description: Il presente lavoro di ricerca, che prende le mosse da un’attività di studio avviata dal Professor Antonio V. Nazzaro negli anni Ottanta del secolo scorso, intende proseguire e portare a termine un percorso intrapreso durante la Laurea Magistrale in «Filologia, letterature e civiltà del mondo antico» e confluito in una tesi dal titolo L’Oratio ad Sanctorum Coetum di Costantino il Grande (2007).
Più in particolare, in questa sede si approfondiscono le questioni connesse con la versione greca della IV Ecloga di Virgilio e con il relativo commento co-stantiniano, tramandati ai capitoli XIX-XXI della suddetta Oratio. Il lavoro si articola in cinque sezioni, che non mirano solo a una precisa e rigorosa analisi testuale, ma intendono chiarire anche le modalità del riutilizzo del componi-mento virgiliano da parte dell’imperatore.
Nello specifico, il Capitolo 1 ripercorre la storia degli studi sul discorso di Costantino, con particolare attenzione alle questioni relative all’autenticità e alla datazione. Ampio spazio è dedicato anche alla tradizione manoscritta, con una dettagliata descrizione dei codici che tramandano l’opera.
Il Capitolo 2 si sofferma invece sulla IV Ecloga greca, trattando i problemi di attribuzione e di datazione, e gli aspetti formali e contenutistici più rilevanti. Il discorso viene quindi ampliato ai casi più significativi del Fortleben cristiano del carme di Virgilio.
Il Capitolo 3 presenta il testo e la traduzione italiana della IV Ecloga greca e del relativo commento costantiniano. Il testo, in particolare, è fornito di un apparato che rende conto dello stato della tradizione.
Il Capitolo 4 si sofferma quindi sull’analisi retorico-formale della IV Ecloga greca, con l’obiettivo non solo di spiegare le scelte del traduttore rispetto al modello, ma anche di individuare e precisare gli intertesti che intessono la trama poetica del componimento.
Il Capitolo 5 prende invece in esame il commento di Costantino e i suoi rapporti con originale latino e traduzione greca della IV Ecloga, sottolineando, in particolare, le modalità del riutilizzo del carme a fini propagandistici.
Il lavoro si chiude con una sezione dedicata alle conclusioni, seguita da una dettagliata bibliografia.
Dynamic Jahn-Teller effect in electron transport through single C60 molecules
Creators: name: Frederiksen, T.
name: Franke, K. J.
name: Arnau, A.
name: Schulze, G.
name: Pascual, J. I.
name: Lorente, N.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Scanning tunneling spectra on single C60 molecules that are sufficiently decoupled from the substrate exhibit a characteristic fine structure, which is explained as due to the dynamic Jahn-Teller effect. Using electron-phonon couplings extracted from density functional theory we calculate the tunneling spectrum through the C60- anionic state and find excellent agreement with measured data.
description: 4 pages, 3 figures, 1 table
Pseudo-random Sequences Generated by Cellular Automata
Creators: name: Martin, Bruno
name: Solé, Patrick
Publisher: name: arXiv
Year: 2008
Subjects: subject: Discrete Mathematics (cs.DM)
subject: FOS: Computer and information sciences

description: Generation of pseudo random sequences by cellular automata, as well as by hybrid cellular automata is surveyed. An application to the fast evaluation and FPGA implementation of some classes of boolean functions is sketched out.
EFFECT OF POLYPLOIDIZATION ON THE TRASCIPTOME AND METABOLOME IN SINTETHIC POLYPLOIDS OF SOLANUM spp
Creators: name: Fasano, Carlo
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2013

description: Polyploidy is very common within angiosperms. Extensive studies are available only in synthetic allopolyploids. By contrast, less is known about the consequences of autopolyploidization. Our research aimed to assess the occurrence and extent of transcriptional and metabolomic changes occurring after oryzaline-induced polyploidization of Solanum commersonii and S. bulbocastanum, two diploid (2n=2×=24) potato species widely used in breeding programmes. Whole-genome expression profiling of diploid and the synthetic tetraploids they derived from were studied in both species to identify the genes exhibiting ploidy-dependent expression changes. Using a Combimatrix CustomArray 90K chip we found about 10% of all the transcriptome. Most of responses to polyploidization were species- and genotype-dependent. Comparing 4x versus 2x, it was clear that in S. commersonii a higher number of differentially expressed genes than in S. bulbocastanum, was observed. Interestingly, we found three genes whose expression changed in both species in a ploidy linked way. Bioinformatics analyses allowed to identify changes in expression “carbohydrates metabolism” and “stress response” genes in S. bulbocastanum and S. commersonii polyploids. A “global” metabolomics profiling was carried out on 170 targeted molecules by LC-ESI(+)-MS analysis. We observed a surprising metabolome alteration in the tetraploids of both species, in disagreement with previous studied reporting only few metabolic alterations associated to genome doubling. A major qualitative and quantitative impact was found in S. commersonii tetraploids. By contrast, in S. bulbocastanum lower changes occurred in important metabolite classes (glycoalkaloids, sugars). In particular, the anthocyanin pathway in tetraploids versus diploids comparisons was significantly affected, in both species. Therefore, a deeper investigation on the molecular causes beyond such accumulation was carried out. We studied the expression of R2R3 MYB an1 transcriptional factor, ans and dfr genes. In S. bulbocastanum our results on gene expression analyses were consistent with the down-accumulation found in tetraploids respect to diploid parent. By contrast, in S. commersonii polyploids the gene expression profiles were not consistent with the drastic accumulation of anthocyanins observed. Further investigations are required, but we believe that answering to this question may produce an important scientific finding with practical breeding applications.
Continuous quantum error correction for non-Markovian decoherence
Creators: name: Oreshkov, Ognyan
name: Brun, Todd A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the effect of continuous quantum error correction in the case where each qubit in a codeword is subject to a general Hamiltonian interaction with an independent bath. We first consider the scheme in the case of a trivial single-qubit code, which provides useful insights into the workings of continuous error correction and the difference between Markovian and non-Markovian decoherence. We then study the model of a bit-flip code with each qubit coupled to an independent bath qubit and subject to continuous correction, and find its solution. We show that for sufficiently large error-correction rates, the encoded state approximately follows an evolution of the type of a single decohering qubit, but with an effectively decreased coupling constant. The factor by which the coupling constant is decreased scales quadratically with the error-correction rate. This is compared to the case of Markovian noise, where the decoherence rate is effectively decreased by a factor which scales only linearly with the rate of error correction. The quadratic enhancement depends on the existence of a Zeno regime in the Hamiltonian evolution which is absent in purely Markovian dynamics. We analyze the range of validity of this result and identify two relevant time scales. Finally, we extend the result to more general codes and argue that the performance of continuous error correction will exhibit the same qualitative characteristics.
description: 16 pages, 4 figures, minor typos corrected, references updated