cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Probing possible effects of circumgalactic media on the metal content of galaxies through the mass-metallicity relationship
Creators: name: Zhai, Sai
name: Shi, Yong
name: Chen, Jianhang
name: Bing, Longji
name: Chen, Yanmei
name: Yu, Xiaoling
name: Li, Songlin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The circumgalactic medium (CGM) connects the gas between the interstellar medium (ISM) and the intergalactic medium, which plays an important role in galaxy evolution. We use the stellar mass-metallicity relationship to investigate whether sharing the CGM will affect the distribution of metals in galaxy pairs. The optical emission lines from the Sloan Digital Sky Survey Data Release (SDSS DR7) are used to measure the gas-phase metallicity. We find that there is no significant difference in the distribution of the metallicity difference between two members in star forming-star forming pairs ($\rm Δlog(O/H)_{diff}$), metallicity offset from the best-fitted stellar mass-metallicity relationship of galaxies in pairs ($\rm Δlog(O/H)_{MS}$), as compared to "fake" pairs. By looking at $\rm Δlog(O/H)_{diff}$ and $\rm Δlog(O/H)_{MS}$ as a function of the star formation rate (SFR), specific star formation rate (sSFR), and stellar mass ratio, no difference is seen between galaxies in pairs and control galaxies. From our results, the share of the CGM may not play an important role in shaping the evolution of metal contents of galaxies.
description: 11 pages, 8 figures, accepted for publication in MNRAS
Transparency on underlying values is needed for useful equity measurements
Creators: name: Pollack, Adam
name: Helgeson, Casey
name: Kousky, Carolyn
name: Keller, Klaus
Publisher: name: Zenodo
Year: 2023

description: Poster for AGU23. Presented during the "H33P: Integrating Social, Scientific, and Engineering Approaches to Identify and Address Gaps in Water Infrastructure and Household Water Security II Poster" session.
Spatio-temporal delay in photoionization by polarization structured laser fields
Creators: name: Wätzel, Jonas
name: Berakdar, Jamal
Publisher: name: arXiv
Year: 2021
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Focused laser fields with textured polarization on a sub-wavelength scale allow extracting information on electronic processes which are not directly accessible by homogeneous fields. Here, we consider photoionization in radially and azimuthally polarized laser fields and show that, due to the local polarizations of the transversal and the longitudinal laser electric field components, the detected photoelectron spectra depend on the atom position from which the electron originates. The calculation results reported here show the angular dependence of the photoionization amplitude, the quantum phase, and the time delay of the valence shell electrons as the parent atom's position varies across the laser spot. We discuss the possibility of using the photoelectron spectra to identify the position of the ionized atom within the laser spot on the sub-wavelength scale. The proposal and its illustrations underline the potential for the detection of the atomic position based on attosecond streaking methods.
description: 10 pages, 6 figures, accepted at PRA
Mejoramiento en la Administración de las Cooperativas Agrícolas
Creators: name: Manuel, Milton L.
name: Manuel, Milton L.
Publisher: name: Unknown
Year: 1965
Subjects: Agribusiness
Financial Economics
Labor and Human Capital

description: Esta publicacíón se refiere a un aspect critico de las actividades de las cooperativas—la administración de las cooperativas. Debido a que el personal administrativo se encuentra siempre muy ocupado en el ejercicio de sus funciones, el material de esta obra se presenta en la forma más breve y concisa posible. El objetivo de esta publicación es mostrar la forma en que se aplican los principios administrativos a las cooperativas locales y la manera en que pueden utilizarse dichos principios para alcanzar el exito en la administración de las cooperativas. Se refiere a aquellas cuestiones generales y funciones administrativas, comunes a las cooperativas de articulos de primera necesidad y de servicio de todos tipos.
description: Informe General No. 120, editado originalmente en inglés por el Servicio de Cooperativas Agricolas, Depto. De Agricultura de los EE. UU. (1964). La presente edición la preparó el Centre Regional de Ayuda Técnica (RTAC), Agenda para el Desarrollo Intemacional (A.I.D.), Departamento de Estado del Gobiemo de los Estados Unidos de América. El Centro es una organización dedicada a la producción de versiones en español del material filmico e impreso de los programas de cooperación técnica de la Alianza para el Progreso.
The Impact of Stellar Clustering on the Observed Multiplicity and Orbital Periods of Planetary Systems
Creators: name: Longmore, Steven N.
name: Chevance, Mélanie
name: Kruijssen, J. M. Diederik
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: It has recently been shown that stellar clustering plays an important role in shaping the properties of planetary systems. We investigate how the multiplicity distributions and orbital periods of planetary systems depend on the 6D phase space density of stars surrounding planet host systems. We find that stars in high stellar phase space density environments (overdensities) have a factor 1.6 - 2.0 excess in the number of single planet systems compared to stars in low stellar phase space density environments (the field). The multiplicity distribution of planets around field stars is much flatter (i.e. there is a greater fraction of multi-planet systems) than in overdensities. This result is primarily driven by the combined facts that: (i) `hot Jupiters' (HJs) are almost exclusively found in overdensities; (ii) HJs are predominantly observed to be single-planet systems. Nevertheless, we find that the difference in multiplicity is even more pronounced when only considering planets in the Kepler sample, which contains few HJs. This suggests that the Kepler dichotomy -- an apparent excess of systems with a single transiting planet -- plausibly arises from environmental perturbations. In overdensities, the orbital periods of single-planet systems are smaller than orbital periods of multiple-planet systems. As this difference is more pronounced in overdensities, the mechanism responsible for this effect may be enhanced by stellar clustering. Taken together, the pronounced dependence of planetary multiplicity and orbital period distributions on stellar clustering provides a potentially powerful tool to diagnose the impact of environment on the formation and evolution of planetary systems.
description: 11 pages, 4 Figures, accepted to ApJL
The Nancy Grace Roman Space Telescope Coronagraph Instrument (CGI) Technology Demonstration
Creators: name: Kasdin, N. Jeremy
name: Bailey, Vanessa P.
name: Mennesson, Bertrand
name: Zellem, Robert T.
name: Ygouf, Marie
name: Rhodes, Jason
name: Luchik, Thomas
name: Zhao, Feng
name: Riggs, A J Eldorado
name: Seo, Young-Joon
name: Krist, John
name: Kern, Brian
name: Tang, Hong
name: Nemati, Bijan
name: Groff, Tyler D.
name: Zimmerman, Neil
name: Macintosh, Bruce
name: Turnbull, Margaret
name: Debes, John
name: Douglas, Ewan S.
name: Lupu, Roxana E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The Coronagraph Instrument (CGI) on the Nancy Grace Roman Space Telescope will demonstrate the high-contrast technology necessary for visible-light exoplanet imaging and spectroscopy from space via direct imaging of Jupiter-size planets and debris disks. This in-space experience is a critical step toward future, larger missions targeted at direct imaging of Earth-like planets in the habitable zones of nearby stars. This paper presents an overview of the current instrument design and requirements, highlighting the critical hardware, algorithms, and operations being demonstrated. We also describe several exoplanet and circumstellar disk science cases enabled by these capabilities. A competitively selected Community Participation Program team will be an integral part of the technology demonstration and could perform additional CGI observations beyond the initial tech demo if the instrument performance warrants it.
description: SPIE Space Telescopes and Instrumentation 2020: Optical, Infrared, and Millimeter Wave, 114431U (15 December 2020)
Antiferromagnetic superexchange interactions in LaOFeAs
Creators: name: Ma, Fengjie
name: Lu, Zhong-Yi
name: Xiang, Tao
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: From first-principles calculations, we have studied the electronic and magnetic structures of the ground state of LaOFeAs. The Fe spins are found to be collinear antiferromagnetic ordered, resulting from the interplay between the strong nearest and next-nearest neighbor superexchange antiferromagnetic interactions. The structure transition observed by neutron scattering is shown to be magnetically driven. Our study suggests that the antiferromagnetic fluctuation plays an important role in the Fe-based superconductors. This sheds light on the understanding of the pairing mechanism in these materials.
description: 5 pages and 7 figures; add the appendix to explain how to determine the nearest and next-nearest Fe-Fe exchange interactions J1 and J2. The overcounting on J1 and J2 in previous version in 2x2 Fe-Fe unit cell with the periodic boundary conditions has been corrected. It is found that J1 is close to J2
BAT99-9 -- a WC4 Wolf-Rayet star with nitrogen emission: Evidence for binary evolution?
Creators: name: Hillier, D. John
name: Aadland, Erin
name: Massey, Philip
name: Morrell, Nidia
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: An analysis of the Large Magellanic Cloud (LMC) WC4 star BAT99-9 (HD 32125, FD 4, Brey 7, WS 3) shows that the star still contains photospheric nitrogen. Three N emission features (N V $λλ1238,1242$, N IV $λ1719$, N IV $λλ3479 - 3485$) are unambiguously identified in the spectrum. CMFGEN models of the star yield a N/C ratio of $0.004 \pm 0.002$ (by number) and a C/He ratio of $0.15_{-0.05}^{+0.10}$. Due to the similarity of BAT99-9 to other WC4 stars, and the good fit achieved by CMFGEN to both the classic WC4 spectrum, and the N lines, we argue that the N lines are intrinsic to BAT99-9. An examination of a limited set of rotating models for single star evolution at LMC and Galactic metallicities shows that a model with a Galactic metallicity ($z=0.014$) and a progenitor mass of around $50\,M_\odot$ can have a N/C ratio similar to, or larger than, what we observe for a significant fraction of its lifetime. However, the LMC models ($z=0.006$) are inconsistent with the observations. Both the single and binary BPASS models predict that many WC stars can have a N/C ratio similar to, or larger than, what we observe for a significant fraction of their lifetime. While the binary models cover a wider range of luminosities and provide a somewhat better match to BAT99-9, it is not currently possible to rule out BAT99-9 being formed through single star evolution, given the uncertainties in mass-loss rates, and the treatment of convection and mixing processes.
description: Accepted for publication in MNRAS
Changing behaviour patterns of disadvantaged unemployed youth through an intervention strategy using computer-based training techniques
Creators: name: Long, Frances Jackia
Publisher: name: University of British Columbia
Year: 2010

description: This thesis is concerned with changing behaviour patterns of a number of unemployed disadvantaged youth associated with an intervention strategy called Career Start. Career Start uses computer-based technology in its instructional program, which attempts to address simultaneously three significant barriers to youth employment. These barriers are grade level attainment, low self-esteem, and destructive attitudes towards work. The participants in Career Start numbered 169 youths between the ages of 15 and 24. All had been classified as severely employment disadvantaged by the classification methods of Employment and Immigration Canada. The youths were interviewed to ascertain specific background characteristics and the reasons why they were unemployed. They were also tested before and after participation in the program to determine whether or not barriers to employment had been reduced. There was some evidence of improvement in academic scores, primarily in the language and mathematics areas. In addition, there was a reduction in the barriers to employment as measured by the Vocational Opinion Index. The Culture Free Self-Esteem Index also showed that the self-esteem of the participants was raised after participation in the program. The employment objectives of Employment and Immigration Canada were also taken into consideration during the study. During the first year the objectives were exceeded by 36 percent of the subjects and, during the first nine-month period of the second year, the objectives were again exceeded. Data were statistically analyzed using the Chi-square Test for Independence, the Non Parametric Sign Test, cross-tabulations, and frequency tables. The study indicated that Career Start had the potential to be a successful intervention strategy in addressing the problems of unemployed and disadvantaged youth. The research also generated a number of related issues in need of further study.
Quasistatic rheology of soft cellular systems using Cellular Potts Model
Creators: name: Villemot, François
name: Durand, Marc
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Soft cellular systems, such as foams or biological tissues, exhibit highly complex rheological properties, even in the quasistatic regime, that numerical modeling can help to apprehend. We present a numerical implementation of quasistatic strain within the widely used cellular Potts model. The accuracy of the method is tested by simulating the quasistatic strain 2D dry foams, both ordered and disordered. The implementation of quasistatic strain in CPM allows the investigation of sophisticated interplays between stress-strain relationship and structural changes that take place in cellular systems.
Analisi di alcuni fattori influenti sul comportamento di paratie di sostegno
Creators: name: Iorio, Carmine
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2013

description: Il presente lavoro ha l'obiettivo di approfondire alcuni aspetti del complesso meccanismo di interazione tra terreno e opera di sostegno tenendo conto sia del processo di realizzazione di quest'ultima sia della natura tridimensionale del problema, in relazione all'eventuale effetto della forma dei singoli elementi che compongono l'opera di sostegno. In particolare si analizza il semplice caso di uno scavo sostenuto da una paratia libera.
On Uniqueness of Boundary Blow-up Solutions of a Class of Nonlinear Elliptic Equations
Creators: name: Dong, Hongjie
name: Kim, Seick
name: Safonov, Mikhail
Publisher: name: arXiv
Year: 2007
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35J65; 35B05

description: We study boundary blow-up solutions of semilinear elliptic equations $Lu=u_+^p$ with $p>1$, or $Lu=e^{au}$ with $a>0$, where $L$ is a second order elliptic operator with measurable coefficients. Several uniqueness theorems and an existence theorem are obtained.
description: To appear in Comm. Partial Differential Equations; 10 pages
High-resolution model studies of the circulation in coastal areas of the Tyrrhenian Sea (including the Gulf of Naples)
Creators: name: De Ruggiero, Paola
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2013

description: The main aim of this PhD research is to study some fundamental aspects of the circulation in a wide South Tyrrhenian coastal area that includes the Gulf of Naples. The primitive equation sigma-coordinate Princeton Ocean Model (POM) has been implemented with high-resolution in that area, and was nested with a circulation model of the whole Tyrrhenian Sea. Modeling the wind-driven circulation was the main task of our study.
Surface ECMWF analysis wind data have been used throughout, but also wind data obtained from X-band SAR data have been used, showing that they provide a potentially valuable tool for improving coastal circulation modeling.
Circulation scenarios typical of different seasons have been simulated. In two cases experimental validation has been successfully performed.
A Systematic Approach to Study Complex Ternary Co-Promoter Interactions: Addition of Ir, Li, and Ti to RhMn/SiO2 for Syngas Conversion to Ethanol
Creators: name: Khatamirad, Mohammad
name: Konrad, Martin
name: Gentzen, Manuel
name: Boscagli, Chiara
name: Almer, Christian
name: Arinchtein, Aleks
name: Geske, Michael
name: Rosowski, Frank
name: Kraehnert, Ralph
Publisher: name: Technische Universität Berlin
Year: 2022
Subjects: subject: 540 Chemie und zugeordnete Wissenschaften
subject: data-driven
subject: syngas
subject: ethanol
subject: multi-promotion
subject: RhMn/SiO2
subject: statistical analysis

description: The direct conversion of synthesis gas could open up economically viable routes for the efficient production of ethanol. RhMn/SiO2 represents one of the most active systems reported thus far. Potential improvements were reported by added dopants, i.e., Ir, Ti, and Li. Yet, combining these elements leads to contradicting results, owing to the complexity of the interactions in a multi-promoted system. This complexity is often encountered in heterogeneous catalysis. We report a systematic data-driven approach for the assessment of complex multi-promoter interactions based on a combination of design-of-experiment, high-throughput experimentation, statistical analysis, and mechanistic assessment. We illustrate this approach for the system RhMn/SiO2 promoted with Ir, Li, and Ti. Using this approach, we investigate the impact of promoters’ interactions on a mechanistic level. Our analysis depicts the means to learn hidden correlations in the performance data and, additionally, high performance for ethanol yield for the RhMnIr/SiO2 catalyst. The method presented outlines an efficient way to also elucidate co-promoter interactions in other complex environments.
Silica‐supported Catalyst System Rh−Mn−Ir−Li−Ti in Syngas to Ethanol Reaction: Reactivity Trends and Performance Optimization
Creators: name: Khatamirad, Mohammad
name: Konrad, Martin
name: Gentzen, Manuel
name: Almer, Christian
name: Boscagli, Chiara
name: Bottke, Nils
name: Geske, Michael
name: Rosowski, Frank
name: Kraehnert, Ralph
Publisher: name: Technische Universität Berlin
Year: 2022
Subjects: subject: 500 Naturwissenschaften und Mathematik::540 Chemie::540 Chemie und zugeordnete Wissenschaften
subject: ethanol
subject: synthesis gas
subject: CO hydrogenation
subject: Rh
subject: high-throughput testing

description: Ethanol is a high‐value chemical that can be produced from syngas derived from fossil or renewable resources. Silica‐supported catalysts based on Rh are reported to show the best performance so far. We report a comprehensive investigation for influence of catalyst composition on performance in syngas conversion to ethanol. We evaluate 53 different silica‐supported catalysts with a varying degree of Rh, Mn, Ir, Li and Ti, via high‐throughput testing. Correlation analysis reveals that Li and Ir tend to increase the selectivity to C2+ oxygenates, and catalysts with a 0.95 molar ratio of Rh : Mn show a tendency for high CO conversion. The composition 2.8Rh, 0.45Mn, 1.3Ir, 0.04Li, where the numbers indicate weight percentage, is identified to yield one of the highest C2+ oxygenate values reported in the literature so far. Moreover, combining this catalyst with a hydrogenation catalyst and converting C2+ oxygenates to ethanol, provides one of the highest ethanol yields reported so far in literature.
Multi-quark potential from AdS/QCD
Creators: name: Wen, Wen-Yu
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: Heavy multi-quark potential in the SU(N) color group using hard-wall AdS/QCD at both zero and finite temperature is studied. A Cornell-like potential is obtained for baryons and other exotic configurations and compared with those in the quenched lattice calculation in N=3 case. At the end we also discuss possible improvements in the UV region of potential.
description: 15 pages, 5 figures, REVTex4
Third-harmonic generation in excitonic insulators
Creators: name: Tanabe, Tetsuhiro
name: Kaneko, Tatsuya
name: Ohta, Yukinori
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study third-harmonic generation (THG) in an excitonic insulator (EI) described in a two-band correlated electron model. Employing the perturbative expansion with respect to the external electric field, we derive the THG susceptibility taking into account the collective dynamics of the excitonic order parameter. In the inversion-symmetric EI, the collective order parameter motion is activated at second order of the external field and its effects arise in THG. We find three peaks in the THG susceptibility at energies $\hbar Ω= Δ_g/3$, $Δ_g/2$, and $Δ_g$, where $Δ_g$ is the band gap. While the THG response at $Δ_g/3$ is caused by bare three-photon excitation of the independent particle across the band gap, the latter two peaks involve the motion of the order parameter activated at second order. The resulting resonant peaks are prominent in particular in the BCS regime but they become less significant in the BEC regime. We demonstrate that the resonant peak originated by the collective excitation is observable in the temperature profile of the THG intensity. Our study suggests that the THG measurement should be promising for detecting the excitonic collective nature of materials.
description: 16 pages, 11 figures
Additional file 1 of Diabetes mellitus-related hospital admissions and prescriptions of antidiabetic agents in England and Wales: an ecological study
Creators: name: AbuHammad, Gayda Abdel Rahman
name: Naser, Abdallah Y.
name: Hassouneh, Loay Khaled Mohammad
Publisher: name: figshare
Year: 2023
Subjects: Medicine
Biotechnology
Chemical Sciences not elsewhere classified
Marine Biology
Science Policy

description: Additional file 1: Supplementary file 1. Figure S1. Rates of hospital admission for diabetes mellitus in England and Wales stratified by age group and type of diabetes mellitus. Figure S2. Rates of hospital admission for diabetes mellitus in England and Wales stratified by gender and type of diabetes mellitus. Figure S3. The time series analysis for the admission rates across the study period. Figure S4. The time series analysis for the prescriptions rates across the study period
ΛCDM suitably embedded in f(R) with a non-minimal coupling to matter
Creators: name: Ortiz-Baños, María
name: Bouhmadi-López, Mariam
name: Lazkoz, Ruth
name: Salzano, Vincenzo
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In this work, we further study a metric modified theory of gravity which contains a non-minimal coupling to matter, more precisely, we assume two functions of the scalar curvature, $f_1$ and $f_2$, where the first one generalises the Hilbert-Einstein action, while the second couples to the matter Lagrangian. On the one hand, assuming a $Λ$CDM background, we calculate analytical solutions for the functions $f_1$ and $f_2$. We consider two setups: on the first one, we fix $f_2$ and compute $f_1$ and on the second one, we fix $f_1$ and compute $f_2$. Moreover, we do the analysis for two different energy density contents, a matter dominated universe and a general perfect fluid with a constant equation of state fuelling the universe expansion. On the other hand, we complete our study by performing a cosmographic analysis for $f_1$ and $f_2$. We conclude that the gravitational coupling to matter can drive the accelerated expansion of the universe.
description: 10 pages, 2 figures. To appear in EPJC
Improved Neuronal Ensemble Inference with Generative Model and MCMC
Creators: name: Kimura, Shun
name: Ota, Keisuke
name: Takeda, Koujin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Machine Learning (cs.LG)
subject: Neurons and Cognition (q-bio.NC)
subject: Machine Learning (stat.ML)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Biological sciences

description: Neuronal ensemble inference is a significant problem in the study of biological neural networks. Various methods have been proposed for ensemble inference from experimental data of neuronal activity. Among them, Bayesian inference approach with generative model was proposed recently. However, this method requires large computational cost for appropriate inference. In this work, we give an improved Bayesian inference algorithm by modifying update rule in Markov chain Monte Carlo method and introducing the idea of simulated annealing for hyperparameter control. We compare the performance of ensemble inference between our algorithm and the original one, and discuss the advantage of our method.
description: 23 pages, 8 figures, partially overlapped with arXiv:1911.06509
Heat flux operator, current conservation and the formal Fourier's law
Creators: name: Wu, Lian-Ao
name: Segal, Dvira
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: By revisiting previous definitions of the heat current operator, we show that one can define a heat current operator that satisfies the continuity equation for a general Hamiltonian in one dimension. This expression is useful for studying electronic, phononic and photonic energy flow in linear systems and in hybrid structures. The definition allows us to deduce the necessary conditions that result in current conservation for general-statistics systems. The discrete form of the Fourier's Law of heat conduction naturally emerges in the present definition.
Quintom Cosmology with General Potentials
Creators: name: Setare, M. R.
name: Saridakis, E. N.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We investigate the phase-space structure of the quintom paradigm in the framework of a spatially flat, open, or closed isotropic and homogeneous universe. We examine the dynamical evolution under the assumption of late-time dark energy domination, without specifying the explicit quintom potential form. The obtained cosmological behavior is qualitatively different than that acquired from the single phantom model.
description: 9 pages, version published at Int. J. Mod. Phys. D
Counting atoms using interaction blockade in an optical superlattice
Creators: name: Cheinet, P.
name: Trotzky, S.
name: Feld, M.
name: Schnorrberger, U.
name: Moreno-Cardoner, M.
name: Foelling, S.
name: Bloch, I.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We report on the observation of an interaction blockade effect for ultracold atoms in optical lattices, analogous to Coulomb blockade observed in mesoscopic solid state systems. When the lattice sites are converted into biased double wells, we detect a discrete set of steps in the well population for increasing bias potentials. These correspond to tunneling resonances where the atom number on each side of the barrier changes one by one. This allows us to count and control the number of atoms within a given well. By evaluating the amplitude of the different plateaus, we can fully determine the number distribution of the atoms in the lattice, which we demonstrate for the case of a superfluid and Mott insulating regime of 87Rb.
description: 4 pages, 4 figures
Conditional Coding and Variable Bitrate for Practical Learned Video Coding
Creators: name: Ladune, Théo
name: Philippe, Pierrick
name: Hamidouche, Wassim
name: Zhang, Lu
name: Déforges, Olivier
Publisher: name: arXiv
Year: 2021
Subjects: subject: Neural and Evolutionary Computing (cs.NE)
subject: Image and Video Processing (eess.IV)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper introduces a practical learned video codec. Conditional coding and quantization gain vectors are used to provide flexibility to a single encoder/decoder pair, which is able to compress video sequences at a variable bitrate. The flexibility is leveraged at test time by choosing the rate and GOP structure to optimize a rate-distortion cost. Using the CLIC21 video test conditions, the proposed approach shows performance on par with HEVC.
Semiclassical corrections to the Einstein equation and Induced Matter Theory
Creators: name: Moyassari, P.
name: Jalalzadeh, S.
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The induced Einstein equation on a perturbed brane in the Induced Matter Theory is re-analyzed. We indicate that in a conformally flat background, the local quantum corrections to the Einstein equation can be obtained via the IMT. Using the FRW metric as the 4D gravitational model, we show that the classical fluctuations of the brane may be related to the quantum corrections to the classical Einstein equation. In other words, the induced Einstein equation on the perturbed brane correspond with the semiclassical Einstein equation.
description: 9 pages, to appear in GRG
1/f Flux Noise in Josephson Phase Qubits
Creators: name: Bialczak, Radoslaw C.
name: McDermott, R.
name: Ansmann, M.
name: Hofheinz, M.
name: Katz, N.
name: Lucero, Erik
name: Neeley, Matthew
name: O'Connell, A. D.
name: Wang, H.
name: Cleland, A. N.
name: Martinis, John M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present a new method to measure 1/f noise in Josephson quantum bits (qubits) that yields low-frequency spectra below 1Hz. Comparison of noise taken at positive and negative bias of a phase qubit shows the dominant noise source to be flux noise and not junction critical-current noise, with a magnitude similar to that measured previously in other systems. Theoretical calculations show that the level of flux noise is not compatible with the standard model of noise from two-level state defects in the surface oxides of the films.
description: 4 pages, 3 figures
Measurement and Scaling Analysis of Rotor-Induced Sediment Mobilization
Creators: name: Perrotta, Gino
Publisher: name: Digital Repository at the University of Maryland
Year: 2014
Subjects: subject: Aerospace engineering
subject: Brownout
subject: Helicopter
subject: Scaling

description: Flow visualization and particle imaging velocimetry (PIV) experiments were conducted in a water tank to investigate the effects of rotor wake and sediment properties on rotor-induced sediment mobilization during hover in ground effect. The two-phase flow was separated into the carrier phase and the dispersed phase for characterization. The carrier phase was studied using PIV to acquire time-resolved planar velocity measurements for a field of view within the rotor wake. The rotor-induced flow was confirmed to be dominated by blade tip vortices and was characterized primarily in terms of the vortex characteristics. Vortices were identified using a tracking function, and were compared to the Lamb-Oseen vortex velocity profile to evaluate their size and strength. The rotor-induced flow was also characterized in terms of wall-jet velocity and turbulent kinetic energy. The dispersed phase was separated using image filtering procedures and was quantified by identifying mobilized sediment particles visible in the field of view. Characteristics of the rotor-induced flow and quantification of sediment mobilization were each averaged over time for several rotor rotations to reduce the effects of wake aperiodicity and asymmetry. New parameter groups were created by combining rotor-induced sediment mobilization system characteristics and each was inspected for correlation with sediment mobilization. Three parameter groups which correlated for all cases measure here are identified and discussed.
Neutrino Mass Hierarchies in a Mass Matrix Form Versus its Inverse Form
Creators: name: Koide, Yoshio
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A neutrino mass matrix model M_νwith M_ν^T =M_νand a model with its inverse matrix form \widetilde{M}_ν= m_0^2 (M_ν^*)^{-1} can be diagonalized by the same mixing matrix U_ν. It is investigated whether a scenario which provides a matrix model M_νwith normal mass hierarchy can also give a model with an inverted mass hierarchy by considering a model with an inverse form of M_ν.
description: 6 pages, 4 figures
EQUITABLE AND PROGRESSIVE DISTANCE-BASED USER CHARGE:  DESIGN AND EVALUATION OF INCOME-BASED MILEAGE FEES IN MARYLAND
Creators: name: Yang, Di
Publisher: name: Digital Repository at the University of Maryland
Year: 2014
Subjects: subject: Transportation planning
subject: Civil engineering
subject: FOS: Civil engineering
subject: Equity
subject: Maryland Statewide Transportation Model (MSTM)
subject: Revenue Generation
subject: Transportation Finance
subject: Vehicle-miles Traveled (VMT) Fees

description: Due to the declining purchasing power of fuel tax revenue, the Highway Trust Fund is insufficient to operate and maintain the surface transportation system in the U.S. Alternative sources of revenue, other than the fuel tax, should be considered to address the insolvency of the funding system. Mileage fees and value pricing have long been attractive options to researchers and decision-makers, but they often raise equity concerns. This paper aims to design and evaluate equitable and progressive distance-based user charge policies, and focuses specifically on income-based fee rate structures. Three variable-rate vehicle-miles traveled (VMT) fee scenarios with respect to income are introduced and all policy scenarios are tested with a statewide transportation model in Maryland. Results show that income-based VMT fees can well protect lower-income households while generating more revenue. However, a standard fee structure based on Ramsey pricing does not work as well as the fixed-percentage incremental fee structure. The latter is progressive across all income groups while ensuring that equity and revenue goals are met.
Quantum and Classical Disparity and Accord
Creators: name: Rabinowitz, Mario
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: Discrepancies and accords between quantum (QM) and classical mechanics (CM) related to expectation values and periods are found for both the simple harmonic oscillator (SHO) and a free particle in a box (FPB), which may apply generally. These indicate non-locality is expected throughout QM. The FPB energy states violate the Correspondence Principle. Previously unexpected accords are found and proven that the classical and quantum expectation values are the same for the expectation value of the second moment and the beat period (i.e. beats between the phases for adjoining energy states) for the SHO for all quantum numbers, n. However, for the FPB the beat periods differ significantly at small n. It is shown that a particle's velocity in an infinite square well varies, no matter how wide the box, nor how far the particle is from the walls. The quantum free particle variances share an indirect commonality with the Aharonov-Bohm and Aharonov-Casher effects in that there is a quantum action in the absence of a force. The concept of an "Expectation Value over a Partial Well Width" is introduced. This paper raises the question as to whether these inconsistencies are undetectable, or can be empirically ascertained. These inherent variances may need to be fixed, or nature is manifestly more non-classical than expected.
description: To be Published in International Journal of Theoretical Physics. Published on line by IJTP 23 Sept.2008: Original at http://www.springerlink.com
Contributions to the Understanding of Wind Turbine Aerodynamics Using a RANS Solver with Transition Modeling
Creators: name: Rinehart, Taylor
Publisher: name: Digital Repository at the University of Maryland
Year: 2014
Subjects: subject: Aerospace engineering
subject: Computational Fluid Dynamics
subject: Transition Modeling
subject: Wind Energy

description: Wind turbine sizes have been steadily increasing to reduce the cost of generating electricity using wind energy. The increased wind turbine blade size has led to increased interest in the accurate prediction of the aerodynamics of large wind turbine blades. In this work, two-dimensional simulations of wind turbine airfoils and three-dimensional simulations of the Sandia 100 m wind turbine blade were conducted. The focus of the simulations was to evaluate improvements in turbulence modeling for wind turbine applications. The flow field was modeled using a Reynolds-Averaged Navier-Stokes flow solver. The turbulence model included transition modeling to capture the significant regions of laminar flow found on wind turbine airfoils and wind turbine blades. The turbulence model was also modified to increase sensitivity to adverse pressure gradients. The effects of modifying the turbulence modeling were quantified using lift and drag for two-dimensional simulations while wind turbine thrust and power were used as metrics for three-dimensional simulations. The two-dimensional studies showed that the adverse pressure gradient correction lowered lift predictions post-stall by about 13%, significantly reducing lift over-prediction and bringing simulations closer to experimental results. Transition modeling lowered drag predictions by 30% to 50% at low angles of attack bringing the predicted values into good agreement with experimental results. The addition of transition modeling in the three-dimensional simulations increased the predicted thrust by 1% to 3% and predicted power by 3% to 6%. The extent of laminar flow was visualized using intermittency. Laminar flow was observed on large portions of the Sandia 100 m blade at normal operating conditions. A preliminary study on the effects of leading edge tubercles on the Sandia 100 m blade was performed, no significant changes in wind turbine performance were observed at nominal operating conditions.
V.S. Naipaul: lo sguardo e la ricomposizione identitaria in The Enigma of Arrival
Creators: name: Tiengo, Adele
Publisher: name: Università degli  Studi di Milano
Year: 2015
Subjects: Letteratura postcoloniale; V.S. Naipaul; Sguardo in letteratura; Giorgio De Chirico; Arte e riproduzione tecnica

description: In this essay I will explore Naipaul’s novel The Enigma of Arrival (1987), focusing on the problematic theme of identity in relation to visual perception. It is my aim to analyze how his use of visual art – with particular reference to painters John Constable and Giorgio de Chirico – confirms the preeminence of visual fruition on other forms of experience in the development of the narrative. First, I will expose Naipaul's choice to deliver to his readership a text that complicates not only the idea of national belonging, but also the notions of literary genre and canon. Then, I will focus on a close reading of the first section of the novel by analyzing his use of the term pairs see/know and change/death. Finally, I will show that it is along these two traces and, more specifically, along the preferential trajectory of sight, that the narrator interrogates himself about his quest for identity.

The narrator approaches both Constable’s and De Chirico’s paintings through reproductions and he strongly emphasizes the second-hand quality of his experience of art fruition. Rather than a matter of purely aesthetic observations, Naipaul’s focus on reproductions is a means through which the narrator gives voice to his colonial anxieties in a changing world. The window can serve as a useful metaphor – and indeed, it frequently appears in the text – for the obstacles, fences, and filters that separate subject and object of observation.
description: Altre Modernità, 2015: NUMERO SPECIALE Finestre: sguardi e riflessi, trasparenze e opacità
|V_{ub}| from the Spectrum of B->pi e nu
Creators: name: Ball, Patricia
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: I discuss the results for $|V_{ub}|f_+(0)$ and $|V_{ub}|$ obtained from the spectrum of $B\toπe ν$ and the form factor $f_+(q^2)$ from QCD sum rules on the light-cone and unquenched lattice calculations; the shape of $f_+(q^2)$ is fixed from experimental data.
description: Proceedings of FPCP07, Bled, Slovenia
Alle soglie dell'osceno. Poetiche della profanazione in Sara de Ibáñez e Alejandra Pizarnik
Creators: name: Salvi, Luca
Publisher: name: Università degli  Studi di Milano
Year: 2015
Subjects: Sara de Ibáñez; Alejandra Pizarnik; infanzia; silenzio; estetica della negatività; etica della scrittura

description: Moving from Adorno’s statement about the enigmatic nature of modern aesthetics, this paper aims to analyse the forms the enigma takes in the works of the Uruguayan and Argentinian poets Sara de Ibáñez and Alejandra Pizarnik. The essay will consider the figures and the shapes of the enigma as they appear in both poetries. Proper of the revelation of the enigma through its profanation by the poetic language is, in fact, the never-ending and mutual reflection of two different states of the being. Through Martin Heidegger and Giorgio Agamben’s studies on language and negativity, the way in which the enigmatic word appears continuously in its constitutive suspension between infancy and adulthood, absence of time and history, language and silence, the Self and the Other will be revealed. Through the resulting dichotomy of matter and form, emerging from a passage of Agostino’s De natura boni, it will be possible, in conclusion, to recognise in the silent form of the enigma the embryonic proposal of a poetical ethics of writing.
description: Altre Modernità, 2015: NUMERO SPECIALE Finestre: sguardi e riflessi, trasparenze e opacità
Forster signatures and qubits in optically driven quantum dot molecules
Creators: name: Rolon, Juan E.
name: Ulloa, Sergio E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: An interesting approach to achieve quantum gate operations in a solid state device is to implement an optically driven quantum gate using two vertically coupled self-assembled quantum dots, a quantum dot molecule (QDM). We present a realistic model for exciton dynamics in InGaAs/GaAs QDMs under intense laser excitation and applied electric fields. The dynamics is obtained by solutions of the Lindblad master equation. A map of the dressed ground state as function of laser energy and applied electric field exhibits rich structure that includes excitonic anticrossings that permit the identification of the relevant couplings. The optical signatures of the dipole-dipole Forster energy transfer mechanism show as splittings of several (spatially) indirect excitonic lines. Moreover, we construct a model for exciton qubit rotations by adiabatic electric field cyclic sweeps into a Forster-tunneling regime which induces level anticrossings. The proposed qubit exhibits Rabi oscillations among two well defined exciton pairs as function of the residence time at the anticrossing.
description: Paper presented in the International Conference on Electronic Properties of Two-dimensional Systems and Modulated Semiconductor Structures Genova Magazzini del Cotone, July 15-20 2007
Supplementary document for Ultra-clean ternary Au/Ag/AgCl nanochains favoring cryogenic temperature-boosted broadband SERS ultrasensitive detection - 6523722.pdf
Creators: name: Xu, Linlin
name: Chen, Ming
name: Cui, Qingqiang
name: wang, chang
name: Zhang, Mengya
name: zheng, linqi
name: Li, Shuang
name: Zhang, Hua
name: Liang, Guangda
Publisher: name: Optica Publishing Group
Year: 2023
Subjects: Uncategorized

description: Supplemental Document for ultra-clean ternary Au/Ag/AgCl nanoclusters favoring cryogenic temperature-boosted broadband SERS ultrasensitive detection
Geometry-induced rectification for an active object
Creators: name: Lee, Jae Sung
name: Park, Jong-Min
name: Noh, Jae Dong
name: Park, Hyunggyu
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Study on a rectified current induced by active particles has received a great attention due to its possible application to a microscopic motor in biological environments. Insertion of an {\em asymmetric} passive object amid many active particles has been regarded as an essential ingredient for generating such a rectified motion. Here, we report that the reverse situation is also possible, where the motion of an active object can be rectified by its geometric asymmetry amid many passive particles. This may describe an unidirectional motion of polar biological agents with asymmetric shape. We also find a weak but less diffusive rectified motion in a {\em passive} mode without energy pump-in. This "moving by dissipation" mechanism could be used as a design principle for developing more reliable microscopic motors.
description: 6 pages (main), 13 pages (SI)