cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Numerical simulations of gravitational collapse
Creators: name: Pretorius, Frans
Publisher: name: University of British Columbia
Year: 2009

description: In this thesis we present a numerical study of gravitational collapse, within the framework of Einstein's theory of general relativity. We restrict our attention to spacetimes possessing axial symmetry, and incorporate a massless scalar field as the matter source. Our primary objectives are the study of critical phenomena at the threshold of black hole formation, and the stable simulation of black hole spacetimes. An integral part of the thesis is concerned with developing the necessary numerical tools and techniques to successfully solve these problems. To that end, we have implemented a variant of Berger and Oliger's adaptive mesh refinement (AMR) algorithm, with enhancements that allow us to incorporate elliptic equations into the AMR framework. Using this code, we simulate critical collapse of axisymmetric distributions of scalar field energy, which is the first time this has been done in the non-perturbative regime. For several classes of initial data, our results are consistent with a hypothesized universal critical solution. However, from the collapse of prolate initial data, we find indications that there may be an additional, non-spherical unstable mode. This putative instability eventually causes a nearcritical echoing solution to bifurcate into two, causally disconnected solutions that each resemble the spherical critical solution. Furthermore, we speculate that this bifurcation process would continue indefinitely at threshold, resulting in an infinite cascade of near-spherical solutions. However, the evidence for this second unstable mode is not conclusive, and more work will be needed, possibly with an enhanced code, to answer this question. To numerically study spacetimes containing black holes, one needs to avoid the singularities that occur inside of the holes. The technique that we have implemented to accomplish this is called black hole excision. This aspect of the code is still work-in-progress, for we have not yet incorporated excision into the AMR-based code, and the class of excision boundary conditions we currently employ are inconsistent with the complete set of field equations. However, we are able to obtain stable simulations using a constrained evolution scheme, and we present two preliminary examples, one showing black hole formation, the other a head-on black hole collision.
Radio Observations of PSR B1259-63 through the 2004 periastron passage
Creators: name: Johnston, Simon
name: Ball, Lewis
name: Wang, N.
name: Manchester, R. N.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report here on extensive radio observations of the binary system containing PSR B1259-63 and the Be star SS 2883, made around the time of the 2004 periastron. This is the fourth periastron to have been observed in detail. As in previous observations, changes in the pulsar's dispersion and rotation measures are detected over a period spanning 200 days. We show that the eclipse of the pulsed emission lasts from 16 days prior to periastron to 15 days after periastron and is consistent from one periastron to the next. We demonstrate that the timing solution proposed by Wang et al. (2004) provides a good fit through the 2004 periastron. The light curve of the transient unpulsed radio emission is broadly similar from one periastron to the next. For this periastron, however, the light curve is strongly peaked post-periastron with rather little enhancement prior to periastron, in contrast to the 2000 periastron where the peak flux densities were more equal. These observations remain consistent with the interpretation that the pulsar passes through the dense circumstellar disk of the Be star just before and just after periastron. The observed differences from one periastron to the next can be ascribed to variations in the local disk density and magnetic field structure at the time the pulsar enters the disk.
description: Accepted by MNRAS. 7 pages, 5 figures
Microcanonical Thermostatistics, the basis for a New Thermodynamics, "heat can flow from cold to hot", and nuclear multifragmentation. The correct treatment of Phase Separation after 150 years of statistical mechanics
Creators: name: Gross, D. H. E.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Equilibrium statistics of finite Hamiltonian systems is fundamentally described by the microcanonical ensemble (ME). Canonical, or grand-canonical partition functions are deduced from this by Laplace transform. Only in the thermodynamic limit are they equivalent to ME for homogeneous systems. Therefore ME is the only ensemble for non-extensive/inhomogeneous systems like nuclei or stars where the $\lim_{N\to \infty,ρ=N/V=const}$ does not exist. Conventional canonical thermo-statistic is inapplicable for non-extensive systems. This has far reaching fundamental and quite counter-intuitive consequences for thermo-statistics in general: Phase transitions of first order are signaled by convexities of $S(E,N,Z,...)$ \cite{gross174}. Here the heat capacity is {\em negative}. In these cases heat can flow from cold to hot! The original task of thermodynamics, the description of boiling water in heat engines can now be treated. Consequences of this basic peculiarity for nuclear statistics as well for the fundamental understanding of Statistical Mechanics in general are discussed. Experiments on hot nuclei show all these novel phenomena in a rich variety. The close similarity to inhomogeneous astro physical systems will be pointed out. \keyword{Microcanonical statistics, first order transitions, phase separation, steam engines, nuclear multifragmentation, negative heat capacity}
description: 6 pages, 3 figures, Invited plenary talk at VI Latin American Symposium on Nuclear Physics and Applications, Iguaz\'u, Argentina. October 3 to 7, 2005
Histogram Reweighting Method for Dynamic Properties
Creators: name: Nieto-Draghi, Carlos
name: Perez-Pellitero, Javier
name: Avalos, Josep Bonet
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The histogram reweighting technique, widely used to analyze Monte Carlo data, is shown to be applicable to dynamic properties obtained from Molecular Dynamics simulations. The theory presented here is based on the fact that the correlation functions in systems in thermodynamic equilibrium are averages over initial conditions of functions of the trajectory of the system in phase-space, the latter depending on the volume, the total number of particles and the classical Hamiltonian. Thus, the well-known histogram reweighting method can almost straightforwardly be applied to reconstruct the probability distribution of initial states at different thermodynamic conditions, without extra computational effort. Correlation functions and transport coefficients are obtained with this method from few simulation data sets.
description: 4 pages, 3 figures
Universality of Nonperturbative Effects in c<1 Noncritical String Theory
Creators: name: Ishibashi, Nobuyuki
name: Kuroki, Tsunehide
name: Yamaguchi, Atsushi
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Nonperturbative effects in c<1 noncritical string theory are studied using the two-matrix model. Such effects are known to have the form fixed by the string equations but the numerical coefficients have not been known so far. Using the method proposed recently, we show that it is possible to determine the coefficients for (p,q) string theory. We find that they are indeed finite in the double scaling limit and universal in the sense that they do not depend on the detailed structure of the potential of the two-matrix model.
description: 17 pages
Non-Geometric Magnetic Flux and Crossed Modules
Creators: name: Kalkkinen, Jussi
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: It is shown that the BRST operator of twisted N=4 Yang-Mills theory in four dimensions is locally the same as the BRST operator of a fully decomposed non-Abelian gerbe. Using locally defined Yang-Mills theories we describe non-perturbative backgrounds that carry a novel magnetic flux. Given by elements of the crossed module G x Aut G, these non-geometric fluxes can be classified in terms of the cohomology class of the underlying non-Abelian gerbe, and generalise the centre ZG valued magnetic flux found by 't Hooft. These results shed light also on the description of non-local dynamics of the chiral five-brane in terms of non-Abelian gerbes.
description: 26 pages, LaTeX; v2: expanded, typos corrected; v3: typos corrected, version to apper in Nucl. Phys. B
On the Topology of the Reduced Classical Configuration Space of Lattice QCD
Creators: name: Charzyński, S.
name: Rudolph, G.
name: Schmidt, M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We study the topological structure of the quotient of $SU(3)\times SU(3)$ by diagonal conjugation. This is the simplest nontrivial example for the classical reduced configuration space of chromodynamics on a spatial lattice in the Hamiltonian approach. We construct a cell complex structure of the quotient in such a way that the closures of strata are subcomplexes and we compute the homology and cohomology groups of the strata and their closures.
description: 33 pages, 3 figures
Fermion Masses and Mixing in Four and More Dimensions
Creators: name: Chamoun, N.
name: Khalil, S.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We give an overview of recent progress in the study of fermion mass and flavor mixing phenomena. Mass matrix ansatze are considered within the SM and SUSY GUTs where some predictive frameworks based on SU(5) and SO(10) are reviewed. We describe a variety of schemes to construct quark mass matrices in extra dimensions focusing on four major classes: models with the SM residing on 3-brane, models with universal extra dimensions, models with split fermions and models with warped extra dimensions. We outline how realistic patterns of quark mass matrices could be derived from orbifold models in heterotic superstring theory. Finally, we address the fermion mass problem in intersecting D-branes scenarios, and present models with D6-branes able to give a good quantitatively description of quark masses and mixing. The role of flavor/CP violation problem as a probe of new physics is emphasized.
description: a review based on seminars presented by S.K. in different places, 34 pages, latex
Classifying the Future of Universes with Dark Energy
Creators: name: Chiba, Takeshi
name: Takahashi, Ryuichi
name: Sugiyama, Naoshi
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We classify the future of the universe for general cosmological models including matter and dark energy. If the equation of state of dark energy is less then -1, the age of the universe becomes finite. We compute the rest of the age of the universe for such universe models. The behaviour of the future growth of matter density perturbation is also studied. We find that the collapse of spherical overdensity region is greatly changed if the equation of state of dark energy is less than -1.
description: references added, to appear in Class. Quantum Grav
Formation of Giant Planets by Concurrent Accretion of Solids and Gas inside an Anti-Cyclonic Vortex
Creators: name: Klahr, Hubert
name: Bodenheimer, Peter
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study the formation of a giant gas planet by the core--accretion gas--capture process, with numerical simulations, under the assumption that the planetary core forms in the center of an anti-cyclonic vortex. The presence of the vortex concentrates particles of centimeter to meter size from the surrounding disk, and speeds up the core formation process. Assuming that a planet of Jupiter mass is forming at 5 AU from the star, the vortex enhancement results in considerably shorter formation times than are found in standard core--accretion gas--capture simulations. Also, formation of a gas giant is possible in a disk with mass comparable to that of the minimum mass solar nebula.
description: 27 pages, 4 figures, ApJ in press
Population inversion of driven two-level systems in a structureless bath
Creators: name: Stace, T. M.
name: Doherty, A. C.
name: Barrett, S. D.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We derive a master equation for a driven double-dot damped by an unstructured phonon bath, and calculate the spectral density. We find that bath mediated photon absorption is important at relatively strong driving, and may even dominate the dynamics, inducing population inversion of the double dot system. This phenomenon is consistent with recent experimental observations.
description: 4 Pages, Added Reference [30] to Dykman, 1979, available at http://www.pa.msu.edu/people/dykman/pub/Sov.J.LowTemp.Phys_5.pdf
An Innovative Approach for Modeling Crop Yield Response to Fertilizer Nutrients
Creators: name: Upadhyay, Bharat Mani
name: Smith, Elwin G.
name: Favret, M. Lucila
name: Upadhyay, Bharat Mani
name: Smith, Elwin G.
name: Favret, M. Lucila
Publisher: name: Unknown
Year: 2006
Subjects: Crop Production/Industries

description: Fertilizer recommendations seldom account for agro-climatic conditions, which are important factors that determine the response to fertilizer and the optimal rate of fertilizer. The nitrogen fertilizer response to open pollinated and hybrid canola types will also impact optimal nitrogen rates. This study used quantile regression to model canola yield response to nitrogen fertilizer. Quantile regression can apply different weights to the residuals, facilitating a response estimation where the agro-climatic conditions are not limiting and the yield response is due to the variable of interest. The economically optimal levels of fertilizers were calculated using the proposed and the conventional least squares procedures of the two canola types in western Canada. Results showed that the effects of nitrogen fertilizer on yield depended on the canola type and on the estimation procedure. Optimal levels of nitrogen for open-pollinated canola were estimated as 91, 115, and 134 kg ha-1 for severe, moderate and low levels of agro-climatic constraints. Hybrid had a higher yield potential, and also required more nitrogen fertilizer (137, 142, and 158 kg ha-1). Unlike conventional approach, proposed approach could benefit producer by recommending less (more) fertilizer when the crop response to fertilizer is expected to be low (high) due to agro-climatic conditions.
Gas Flow Across Gaps in Protoplanetary Disks
Creators: name: Lubow, Steve H.
name: D'Angelo, Gennaro
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We analyze the gas accretion flow through a planet-produced gap in a protoplanetary disk. We adopt the alpha disk model and ignore effects of planetary migration. We develop a semi-analytic, one-dimensional model that accounts for the effects of the planet as a mass sink and also carry out two-dimensional hydrodynamical simulations of a planet embedded in a disk. The predictions of the mass flow rate through the gap based on the semi-analytic model generally agree with the hydrodynamical simulations at the 25% level. Through these models, we are able to explore steady state disk structures and over large spatial ranges. The presence of an accreting Jupiter-mass planet significantly lowers the density of the disk within a region of several times the planet's orbital radius. The mass flow rate across the gap (and onto the central star) is typically 10% to 25% of the mass accretion rate outside the orbit of the planet, for planet-to-star mass ratios that range from 5e-5 to 1e-3.
description: 10 pages, 3 figures, 1 table. To appear in The Astrophysical Journal
The CARMENES search for exoplanets around M dwarfs: Convective shift and starspot constraints from chromatic radial velocities
Creators: name: Baroch, D.
name: Morales, J. C.
name: Ribas, I.
name: Herrero, E.
name: Rosich, A.
name: Perger, M.
name: Anglada-Escudé, G.
name: Reiners, A.
name: Caballero, J. A.
name: Quirrenbach, A.
name: Amado, P. J.
name: Jeffers, S. V.
name: Cifuentes, C.
name: Passegger, V. M.
name: Schweitzer, A.
name: Lafarga, M.
name: Bauer, F. F.
name: Béjar, V. J. S.
name: Colomé, J.
name: Cortés-Contreras, M.
name: Dreizler, S.
name: Galadí-Enríquez, D.
name: Hatzes, A. P.
name: Henning, Th.
name: Kaminski, A.
name: Kürster, M.
name: Montes, D.
name: Rodríguez-López, C.
name: Zechmeister, M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Context. Variability caused by stellar activity represents a challenge to the discovery and characterization of terrestrial exoplanets and complicates the interpretation of atmospheric planetary signals. Aims. We aim to use a detailed modeling tool to reproduce the effect of active regions on radial velocity measurements, which aids the identification of the key parameters that have an impact on the induced variability. Methods. We analyzed the effect of stellar activity on radial velocities as a function of wavelength by simulating the impact of the properties of spots, shifts induced by convective motions, and rotation. We focused our modeling effort on the active star YZ CMi (GJ 285), which was photometrically and spectroscopically monitored with CARMENES and the Telescopi Joan Oró. Results. We demonstrate that radial velocity curves at different wavelengths yield determinations of key properties of active regions, including spot filling factor, temperature contrast, and location, thus solving the degeneracy between them. Most notably, our model is also sensitive to convective motions. Results indicate a reduced convective shift for M dwarfs when compared to solar-type stars (in agreement with theoretical extrapolations) and points to a small global convective redshift instead of blueshift. Conclusions. Using a novel approach based on simultaneous chromatic radial velocities and light curves, we can set strong constraints on stellar activity, including an elusive parameter such as the net convective motion effect.
description: A&A, in press
GREEN MANAGEMENT AND THE NATURE OF TECHNICAL INNOVATION
Creators: name: Deltas, George
name: Harrington, Donna Ramirez
name: Khanna, Madhu
name: Deltas, George
name: Harrington, Donna Ramirez
name: Khanna, Madhu
Publisher: name: Unknown
Year: 2006
Subjects: Environmental Economics and Policy
Research and Development/Tech Change/Emerging Technologies

description: Innovation is a key component of a firm's strategy to improve market competitiveness and operational efficiency as well as to respond effectively to changing consumer preferences and regulations. A firm has the choice of undertaking different types of innovations that differ in the extent to which they involve changes in products, processes or practices and lead to gains in efficiency or brand image. We postulate that the extent and nature of innovation undertaken by a firm depends on its management system which not only influences its organizational structure, but also the incentives for making continual improvement in its technical capabilities, the extent of employee involvement in decision making and the internal communication channels for information sharing. We develop an empirical framework to examine the extent to which a management system promotes innovation and how its effect differs across different types of innovations.
Thermal luminosities of cooling neutron stars
Creators: name: Potekhin, A. Y.
name: Zyuzin, D. A.
name: Yakovlev, D. G.
name: Beznogov, M. V.
name: Shibanov, Yu. A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Ages and thermal luminosities of neutron stars, inferred from observations, can be interpreted with the aid of the neutron star cooling theory to gain information on the properties of superdense matter in neutron-star interiors. We present a survey of estimated ages, surface temperatures and thermal luminosities of middle-aged neutron stars with relatively weak or moderately strong magnetic fields, which can be useful for these purposes. The catalogue includes results selected from the literature, supplemented with new results of spectral analysis of a few cooling neutron stars. The data are compared with the theory. We show that overall agreement of theoretical cooling curves with observations improves substantially for models where neutron superfluidity in stellar core is weak.
description: 23 pages, 3 figures, 2 tables, accepted by MNRAS. In v.2, acknowledgements are supplemented
Manuale d'uso del logo INAF - Istituto Nazionale di Astrofisica
Creators: name: ALOISIO, Francesca Maria
name: CAPRIO, Francesco
name: CASU, Silvia
Publisher: name: Direzione Generale
Year: 2021

description: Nel presente Manuale d'uso sono dettagliate alcune indicazioni utili per l'utilizzo del logo dell'INAF, Istituto Nazionale di Astrofisica, e le modalità per la richiesta di concessione in utilizzo del logo stesso da parte di terzi. Dopo diciassette anni dal suo progetto, il logo ha di recente avuto un restyling curato da Stefano Asili, già ideatore del logo originario. Gli interventi di restyling, pur fatti con mano leggera, sono sostanziali: dalla scelta del carattere tipografico alle proporzioni, agli allineamenti. Segnaliamo infatti l’introduzione di un nuovo carattere tipografico: l’Eurostile di Aldo Novarese. Progettato nel 1962 - su base del precedente Microgramma del 1952, di Alessandro Butti e dello stesso Novarese - l’Eurostile è diventato lo standard dell’immaginario spaziale. Da Hal 9000 di Kubrick a un'innumerevole serie di film, questo carattere perennemente moderno è sembrato irrinunciabile per un ente scientifico che scandaglia ogni giorno gli oggetti più lontani dell’universo. Sono riportati anche alcuni elementi esemplificativi di immagine coordinata e alcune pratiche di utilizzo errato, utili a orientare senza errori i designer che avranno a che fare con la nuova identità. Il risultato è un marchio che non cambia di senso ma acquista in forza, come forte è la decisione di declinare il logo esteso solo in italiano.
Costruisci il Sistema Solare in Scala sulla tua città: un laboratorio divulgativo della serie INAF Online Lab
Creators: name: GIACOMINI, LIVIA
name: MANTOVANI, GIULIA
name: Aloisi, Francesco
Publisher: name: IAPS Roma
Year: 2021

description: Il laboratorio Costruisci il Sistema Solare in scala sulla tua città è uno degli INAF Online Lab, il progetto sviluppato dal Gruppo DD INAF e ospitato su EduINAF, la rivista online dedicata alla Didattica e Divulgazione dell’INAF. L’idea degli INAF Online Lab, laboratori divulgativi ludici da svolgere completamente online, è nata nell’epoca dell’emergenza COVID19 e della successiva trasformazione in eventi online dei Festival della Scienza e dei laboratori didattici normalmente ospitati in queste manifestazioni. In particolare, Costruisci il Sistema Solare in scala sulla tua città è l’evoluzione di un progetto didattico precedentemente progettato e realizzato con le scuole, trasformato in INAF Online Lab grazie all’uso del software Google Earth. In Costruisci il Sistema Solare in scala sulla tua città, gruppi di ragazzi tra gli 8 e i 13 anni partecipano a un’attività guidata online in cui costruiscono un Sistema Solare virtuale in scala tra le vie della propria città per comprendere le reali dimensioni dei pianeti, le loro distanze reciproche e con il Sole. In questo documento descriviamo nel dettaglio il laboratorio e i suoi possibili ulteriori sviluppi.
Wightman function and Casimir densities for Robin plates in the Fulling-Rindler vacuum
Creators: name: Saharian, A. A.
name: Avagyan, R. M.
name: Davtyan, R. S.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Wightman function, the vacuum expectation values of the field square and the energy-momentum tensor are investigated for a massive scalar field with an arbitrary curvature coupling parameter in the region between two infinite parallel plates moving by uniform proper acceleration. We assume that the field is prepared in the Fulling-Rindler vacuum state and satisfies Robin boundary conditions on the plates. The mode-summation method is used with a combination of a variant of the generalized Abel-Plana formula. This allows to extract manifestly the contributions to the expectation values due to a single boundary and to present the second plate-induced parts in terms of exponentially convergent integrals. Various limiting cases are investigated. The vacuum forces acting on the boundaries are presented as a sum of the self-action and 'interaction' terms. The first one contains well known surface divergences and needs a further renormalization. The 'interaction' forces between the plates are investigated as functions of the proper accelerations and coefficients in the boundary conditions. We show that there is a region in the space of these parameters in which the 'interaction' forces are repulsive for small distances and attractive for large distances.
description: 20 pages, 2 figures, discussion added, accepted for publication in Int. J. Mod. Phys. A
The Canadian Bioproducts Industry Analysis of the Bioproduct Development Survey - 2004
Creators: name: Sparling, David
name: Cranfield, John A.L.
name: Henson, Spencer J.
name: Laughland, Pamela
name: Sparling, David
name: Cranfield, John A.L.
name: Henson, Spencer J.
name: Laughland, Pamela
Publisher: name: Unknown
Year: 2006
Subjects: Resource /Energy Economics and Policy

description: Bioproducts are often presented as one of the potential saviours of Canadian agriculture, offering non-food applications for agricultural products. However, relatively little is known about the sector or the characteristics of the firms. This paper presents an analysis of the Canadian bioproducts sector based on the first survey of bioproduct firms in Canada. The survey was performed by Statistics Canada in 2004 using 2003 firm results. The paper analyzes the responses to the bioproducts survey on two important dimensions, by region and firm size. The results indicate that for most of Canada's 232 bioproducts firms, bioproducts are just one part of the business activities, accounting for less than one third of employees and slightly more than one quarter of total firm revenue. Bioproduct activities provide both market and environmental benefits. The major challenges to the industry are financing and regulation. However, the relative importance of bioproducts, benefits and strategies and the focus and success of firms vary dramatically by region and by firm size.
Additional file 1 of Normalizing inconvenience to promote childhood vaccination: a qualitative implementation evaluation of a novel Michigan program
Creators: name: Lillvis, Denise F.
name: Willison, Charley
name: Noyes, Katia
Publisher: name: figshare
Year: 2020
Subjects: subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: Science Policy

description: Additional file 1. Full Interview Guide. Full IRB-approved interview guide developed for this study
Local spin transfer torque and magnetoresistance in domain walls with variable width
Creators: name: Kazemi, Hamidreza
name: Eggert, Sebastian
name: Sedlmayr, Nicholas
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Use of a spin polarized current for the manipulation of magnetic domain walls in ferromagnetic nanowires has been the subject of intensive research for many years. Recently, due to technological advancements, creating nano-contacts with special characteristics is becoming more and more prevalent. We now present a full quantum investigation of the magnetoresistance and the spin transfer torque in a domain wall, which is embedded in a nano-contact of Ni$_{80}$Fe$_ {20}$, where the size of the domain wall becomes a relevant tunable parameter. The dependence on the domain wall width as well as the spatial dependence of the torque along the domain wall can be analyzed in complete detail. The magnetoresistance drops with increasing domain wall width as expected, but also shows characteristic modulations and points of resonant spin-flip transmission. The spin transfer torque has both significant in-plane and out-of-plane contributions even without considering relaxation. A closer inspection identifies contributions from the misalignment of the spin density for short domain walls as well as an effective gauge field for longer domain walls, both of which oscillate along the domain wall.
description: 8 pages, 9 figures. More information and the latest version can be found here: https://www.physik.uni-kl.de/eggert/papers/index.html
Alberta's Water for Life Strategy: Some early indications of its acceptance by the irrigation industry in Southern Alberta
Creators: name: Bjornlund, Henning
name: Nicol, Lorraine A.
name: Klein, Kurt K.
name: Bjornlund, Henning
name: Nicol, Lorraine A.
name: Klein, Kurt K.
Publisher: name: Unknown
Year: 2006
Subjects: Resource /Energy Economics and Policy

description: Water is essential for sustainable agricultural development - for irrigation of crops, livestock watering, processing, and sustaining farm families. Agriculture uses 71 percent of all water diverted for consumptive use in Canada (Environment Canada, 2004), and is by far the greatest water consumer in Canada. In the absence of a Canadian national water strategy, Alberta has developed a long-term water management plan called the Water for Life Strategy. Its successful implementation will depend largely on the participation of irrigators. This study explores the reaction of irrigators to one of the strategy's main goals - a 30 percent increase in water use efficiency and productivity by 2015 over 2005 levels. The study reveals that irrigators vary significantly in their views as to the extent to which this goal can be reached, and the means by which it should be achieved within agriculture. Further, these responses reflect differences among irrigation districts relating to the extent of water stress, on-farm irrigation water efficiency and natural factors that limit crop diversity in some areas. Ultimately the government may have to revise its 30 percent target and tailor the strategy to irrigation districts as opposed to a broad-based approach.
Monte Carlo approach of the islanding of polycrystalline thin films
Creators: name: Lallet, F.
name: Bachelet, R.
name: Dauger, A.
name: Olivi-Tran, N.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We computed by a Monte Carlo method derived from the Solid on Solid model, the evolution of a polycrystalline thin film deposited on a substrate during thermal treatment. Two types of substrates have been studied: a single crystalline substrate with no defects and a single crystalline substrate with defects. We obtain islands which are either flat (i.e. with a height which does not overcome a given value) or grow in height like narrow towers. A good agreement was found regarding the morphology of numerical nanoislands at equilibrium, deduced from our model, and experimental nanoislands resulting from the fragmentation of YSZ thin films after thermal treatment.
description: 20 pages, 7 figures
Trainspotting: Extraction and Analysis of Traffic and Topologies of Transportation Networks
Creators: name: Kurant, Maciej
name: Thiran, Patrick
Publisher: name: arXiv
Year: 2005
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: The knowledge of real-life traffic pattern is crucial for good understanding and analysis of transportation systems. This data is quite rare. In this paper we propose an algorithm for extracting both the real physical topology and the network of traffic flows from timetables of public mass transportation systems. We apply this algorithm to timetables of three large transportation networks. This enables us to make a systematic comparison between three different approaches to construct a graph representation of a transportation network; the resulting graphs are fundamentally different. We also find that the real-life traffic pattern is very heterogenous, both in space and traffic flow intensities.
description: 9 pages, 7 figures
Supernovae Shedding Light on Gamma-Ray Bursts
Creators: name: Della Valle, M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We review the observational status of the Supernova (SN)/Gamma-Ray Burst (GRB) connection. In section 2 we provide a short summary of the observational properties of core-collapse SNe. In sections 3-6 we review the circumstantial evidences and the direct observations that support the existence of a deep connection between the death of massive stars and GRBs. Present data suggest that SNe associated with GRBs form a heterogeneous class of objects including both bright and faint Hypernovae and perhaps also `standard' Ib/c events. In section 7, we provide an empirical estimate of the rate of Hypernovae, for a ``MilkyWay-like'' galaxy, of about $\sim 2.6\times 10^{-4}$ yr$^{-1}$ that may imply the ratio GRB/Hypernovae to be in the range $\sim 0.03-0.7$. In the same framework we find the ratio GRB/SNe-Ibc to be $\sim 0.008÷0.05$. In section 8 we discuss the possible existence of a lag between the SN explosion and the associated gamma-ray event. In the few SN/GRB associations so far discovered the SN explosions and GRB events appear to go off simultaneously. In section 9 we present the conclusions and highlight the open problems that Swift hopefully will allow us to solve.
description: 20 pages, 13 figures, invited review at the 4th Workshop Gamma-Ray Bursts in the Afterglow Era, Rome,18-22 October 2004. Editors: L. Piro, L. Amati, S. Covino, and B. Gendre. Il Nuovo Cimento, in press
Decoupling of self-diffusion and structural relaxation during a fragile-to-strong crossover in a kinetically constrained lattice gas
Creators: name: Pan, Albert C.
name: Garrahan, Juan P.
name: Chandler, David
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We present an interpolated kinetically constrained lattice gas model which exhibits a transition from fragile to strong supercooled liquid behavior. We find non-monotonic decoupling that is due to this crossover and is seen in experiment.
description: 3 pages, 3 figures, in press at Chem. Phys. Chem
RISK EFFICIENCY OF ALTERNATE CANOLA MANAGEMENT DECISIONS
Creators: name: Upadhyay, Bharat Mani
name: Smith, Elwin G.
name: Clayton, George
name: Harker, Neil
name: Upadhyay, Bharat Mani
name: Smith, Elwin G.
name: Clayton, George
name: Harker, Neil
Publisher: name: Unknown
Year: 2004
Subjects: Risk and Uncertainty

description: This study evaluates profitability and risk associated with eighteen different management decisions for canola production in Alberta. Expected payoff from cultivar selection outweighs the payoff from time of seeding and from time of weed control. Expected payoff was higher from hybrid compared to inbred cultivars. Early spring seeding was more profitable than fall or mid-May seeding. A typical decision in the sample showed positive and significant upper limit risk-expected return tradeoffs. The generalized stochastic dominance analysis revealed that early spring seeding was dominant over fall and mid-May seeding across all risk averse and risk neutral farmers. Weed control at the six-leaf stage was risk efficient for a risk averter. A risk neutral farmer preferred weed control at the three to four-leaf stage or six-leaf stage, depending on cultivar.
Li and Be depletion in metal-poor subgiants
Creators: name: Pérez, A. E. García
name: Primas, F.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A sample of metal-poor subgiants has been observed with the UVES spectrograph at the Very Large Telescope and abundances of Li and Be have been determined. Typical signal-to-noise per spectral bin values for the co-added spectra are of the order of 500 for the Li I line (670.78 nm) and 100 for the Be II doublet lines (313.04 nm). The spectral analysis of the observations was carried out using the Uppsala suite of codes and MARCS (1D-LTE) model atmospheres with stellar parameters from photometry, parallaxes, isochrones and Fe II lines. Abundance estimates of the light elements were corrected for departures from local thermodynamic equilibrium in the line formation. Effective temperatures and Li abundances seem to be correlated and Be abundances correlate with [O/H]. Standard models predict Li and Be abundances approximately one order of magnitude lower than main-sequence values which is in general agreement with the observations. On average, our observed depletions seem to be 0.1 dex smaller and between 0.2 and 0.4 dex larger (depending on which reference is taken) than those predicted for Li and Be, respectively. This is not surprising since the initial Li abundance, as derived from main-sequence stars on the Spite plateau, may be systematically in error by 0.1 dex or more, and uncertainties in the spectrum normalisation and continuum drawing may affect our Be abundances systematically.
description: Accepted for publication in A&A
An approach to chaotic synchronization
Creators: name: Hramov, Alexander E.
name: Koronovskii, Alexey A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: This paper deals with the chaotic oscillator synchronization. A new approach to the synchronization of chaotic oscillators has been proposed. This approach is based on the analysis of different time scales in the time series generated by the coupled chaotic oscillators. It has been shown that complete synchronization, phase synchronization, lag synchronization and generalized synchronization are the particular cases of the synchronized behavior called as "time-scale synchronization". The quantitative measure of chaotic oscillator synchronous behavior has been proposed. This approach has been applied for the coupled Rössler systems and two coupled Chua's circuits.
description: 10 pages, 11 figures, published in Chaos, 14, 3 (2004) 603-610
The anisotropic microwave electrodynamics of YBCO
Creators: name: Hosseini-Gheinani, Ahmad Reza
Publisher: name: University of British Columbia
Year: 2009

description: The anisotropic microwave surface impedance of the high temperature superconductor, YBa₂Cu₃O[sub 7‒δ], has been investigated. Microwave spectroscopy using five microwave cavities has been used to show clearly the development of long lived quasiparticles (QP) in the ab-plane of YBa₂Cu₃O₆.₉₉. Two regimes of transport are found, one below 20 K where the quasiparticle (QP) dynamics is with residual impurities, and above 20 K where umklapp QP-QP interactions dictate the temperature dependence of the transport lifetimes. The c-axis microwave surface impedance of YBa₂Cu₃O₆.₉₅ has been studied into the superconducting state. The long QP lifetimes found in the planes of this material are found to be absent in the conductivity observed along the ĉ-axis, indicating that the confinement of carriers to the planes is an inherent feature of the cuprates. The highly underdoped superconducting state has also been investigated with microwave techniques. The temperature dependence of the ĉ-axis superfluid stiffness is found to scale over a range of hole dopings, corresponding to T[sub c]'s in the range 9-19 K. We further find that the magnitude of the zero temperature c-axis superfluid stiffness grows rapidly with doping, initially as fast as T[sub c]².
EVALUATING ECONOMICS OF GREENHOUSE GAS EMISSION UNDER HIGH AND LOW INPUTS FARMING SYSTEM
Creators: name: Khakbazan, Mohammad
name: Monreal, M.
name: Derksen, D.A.
name: Zentner, Robert P.
name: Khakbazan, Mohammad
name: Monreal, M.
name: Derksen, D.A.
name: Zentner, Robert P.
Publisher: name: Unknown
Year: 2004
Subjects: Environmental Economics and Policy

description: A serious concern about the sustainability of existing production systems has resulted from the low profitability of agriculture and the deterioration of the natural resource base. As a result of these concerns, increased attention has been given to alternative farming practices in order to decrease the use of fossil fuels, to enhance the efficiency of nitrogen fertilization, and to increase the implementation of conservation tillage practices. Farmers are recommended to include pulse crop into their rotation since legumes form symbiotic associations with bacteria that can fix atmospheric N2 reducing the need of nitrogen fertilizer application and the emission of greenhouse gas (GHG) production. The objective of this study was to evaluate the economics of greenhouse gas mitigation for different cropping systems and management practices. Data from a 5-year study of a wheat-pea rotation, under different seeding systems and fertilizer and herbicide rates, was used to examine economic and greenhouse gas performance. Based on IPCC estimations of nitrous oxide (N2O) emissions, comparisons were made to measured N2O rates to determine if the difference between these figures were significant. Comparison of actual measured N2O emissions to estimations based on IPCC indicated that the measure emission rate was significantly lower than estimated values for the site. Results for low-fertilizer rates, under a low-disturbance system, suggests there is greater net carbon fixed as compared to the high-disturbance practices in both wheat and pea. Overall, the decreased use of fertilizer (50% to 75% of recommended rates) under a low-disturbance seeding-system was preferable, based upon environmental-economic indicators.
FINANCIAL AND HEALTH COSTS OF PESTICIDE USE IN GROWING CONVENTIONAL AND GENETICALLY MODIFIED POTATOES IN PRINCE EDWARD ISLAND
Creators: name: Adamowicz, Wiktor L.
name: Veeman, Michele M.
name: White, Elspeth
name: Adamowicz, Wiktor L.
name: Veeman, Michele M.
name: White, Elspeth
Publisher: name: Unknown
Year: 2004
Subjects: Environmental Economics and Policy

description: The majority of potato farming in Canada occurs in tightly clustered geographic locations and requires substantial chemical inputs. The possibility of pesticide drift, pesticide residues on food and the effect of pesticides on the environment, leads to interest in quantifying the different effects that pesticides may have on human health and the environment. This study focuses on the potential use of genetically modified potatoes, the associated issue of pesticide residues in the air, and the potential impact of this on the health of farmers, their families, and others in the context of Prince Edward Island. Reductions in costs of potato farming and reduced health costs that may be associated with lower pesticide applications in growing genetically engineered potatoes (NewLeaf, NewLeaf Plus and NewLeaf Pro potatoes, each genetically modified for particular traits), relative to conventional potato growing practices in Prince Edward Island are identified and quantified. It is concluded that the financial benefits from the use of fewer inputs with the modified potatoes are significant while the health benefits associated with reduced exposure to pesticides are relatively small.
Additional file 4 of Long-term transmission patterns and public health policies leading to malaria elimination in Panamá
Creators: name: Hurtado, Lisbeth
name: Cumbrera, Alberto
name: Chystrie Rigg
name: Milixa Perea
name: Santamaría, Ana María
name: Chaves, Luis Fernando
name: Dianik Moreno
name: Romero, Luis
name: Lasso, Jose
name: Caceres, Lorenzo
name: Azael Saldaña
name: Calzada, Jose E.
Publisher: name: figshare
Year: 2020
Subjects: subject: 29999 Physical Sciences not elsewhere classified
subject: FOS: Physical sciences
subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: Science Policy
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: Computational Biology

description: Additional file 4: Table S1 Imported malaria cases in Panamá by country of origin, 2000 – 2019.
Fratadocchi, Tommaso Breccia: La Chiesa di S.Ejmiacin a Soradir/the church of St. Ejmiacin at Soradir
Creators: name: Wessel, Klaus
Publisher: name: Oriens christianus : Hefte für die Kunde des christlichen Orients
Year: 2024

description: Oriens christianus : Hefte für die Kunde des christlichen Orients, Bd. 58 (1974): Oriens christianus, Band 58
A search for supernova neutrinos with the Sudbury Neutrino Observatory
Creators: name: Heise, Jaret
Publisher: name: University of British Columbia
Year: 2009

description: The Sudbury Neutrino Observatory (SNO) is an underground Cerenkov detector designed to detect neutrinos from astrophysical sources. The fiducial mass of the detector consists of 1000 tonnes of D₂0 , which provides sensitivity to all neutrino flavours. Since much of the energy released in the supernova burst is expected to be carried by the muon and tau neutrinos, the supernova signal recorded by the SNO detector is of particular importance. In addition, SNO is also sensitive to the prompt electron neutrino signal expected from capture processes during core collapse. Various supernova models are investigated and predictions of the SNO supernova signal are studied using simulated Monte Carlo data. A data analysis program to identify neutrinos from a galactic supernova burst has been installed in the online system at SNO. The program automatically analyzes burst data and it is anticipated that a manual alert to the Supernova Early Warning System could be issued within 20-30 minutes with negligible possibility of a false alarm. The burst identification algorithm currently in use both online and offline provides detection sensitivity beyond the far edge of our galaxy. A search for supernova neutrinos was performed using 241.0 days of data collected over the time period between November 2, 1999 and January 4, 2001. No candidate bursts were observed over this period, which places a 90% confidence level upper limit of < 3.5 galactic supernovae per year.