cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Lunar Dust Particles Blown By Lander Engine Exhaust in Rarefied and Compressible Flow
Creators: name: Lane, John E.
name: Metzger, Philip T.
name: Carlson, Jeffrey W.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Previously we presented a numerical model that predicts trajectories of lunar dust, soil, and gravel blown by the engine exhaust of a lunar lander. The model uses the gas density, velocity vector field, and temperature predicted by computational fluid dynamics (CFD) or Direct Simulation Monte Carlo (DSMC) simulations to compute the forces and accelerations acting on the regolith particles, one particle at a time (ignoring particle collisions until more advanced models are developed). Here we present significant improvements to the model, including the implementation of particle drag and lift formulas to account for the rarefaction and compressibility of the flow. It turns out that the drag force is reduced due to the rarefaction, but the lift is increased due to several effects such as particle rotation. A data matrix of particle sizes, engine thrusts (descent and ascent values for Altair), horizontal and vertical starting distances, and lander height above ground, have been tested using the latest version of the software. These results suggest that the previously reported 3 degree trajectory angle limit can be exceeded in several cases by as much as a factor of five. Particles that originate at a height of 1 cm above the surface from an outer crater rim can be propelled to angles of 5 degrees or more. Particles that start at 10 cm above the surface can be ejected with angles of up to 15 degrees. Mechanisms responsible for placing particles at starting heights above the surface may include the kinetics of horizontal collisions, as suggested by Discrete Element Method (DEM) simulations. We also present results showing the distance particles travel and their impact velocities. We then use the model to evaluate the effectiveness of berms or other methods to block the spray of soil at a lunar landing site.
description: 9 pages, 6 figures
Thermal Timescale Mass Transfer Rates in Intermediate-Mass X-ray Binaries
Creators: name: Xu, Xiao-Jie
name: Li, Xiang-Dong
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Thermal timescale mass transfer generally occurs in close binaries where the donor star is more massive than the accreting star. The mass transfer rates are usually estimated in terms of the Kelvin-Helmholtz timescale of the donor star. But recent investigations indicate that this method may overestimate the real mass transfer rates in accreting white dwarf or neutron star binary systems. We have systematically investigated the thermal-timescale mass transfer processes in intermediate-mass X-ray binaries, by calculating binary evolution sequences with various initial donor masses and orbital periods. From the calculated results we find that on average the mass transfer rates are lower than traditional estimates by a factor of $\sim 4$.
description: 13 pages, 4 figures, and 2 tables, accepted for publication in A&A
Simultaneous suppression of ferromagnetism and superconductivity in UCoGe by Si substitution
Creators: name: de Nijs, D. E.
name: Huy, N. T.
name: de Visser, A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We investigate the effect of substituting Si for Ge in the ferromagnetic superconductor UCoGe. Dc-magnetization, ac-susceptibility and electrical resistivity measurements on polycrystalline UCoGe$_{1-x}$Si$_x$ samples show that ferromagnetic order and superconductivity are progressively depressed with increasing Si content and simultaneously vanish at a critical concentration $x_{cr} \simeq 0.12$. The non-Fermi liquid temperature variation in the electrical resistivity near $x_{cr}$ and the smooth depression of the ordered moment point to a continuous ferromagnetic quantum phase transition. Superconductivity is confined to the ferromagnetic phase, which provides further evidence for magnetically mediated superconductivity.
description: 5 pages, 4 figures, accepted for publication in PRB
L'institutionnalisation du régime républicain en France
Creators: name: Premat, Christophe
Publisher: name: Stockholm University
Year: 2021
Subjects: subject: 200306 French Language
subject: FOS: Languages and literature
subject: History

description: Il s'agit d'une présentation en français de l'histoire politique de la France depuis la Révolution française à partir de 1789 dans le cadre du cours "Culture et identité" à l'Université de Stockholm (niveau Français III).
This is a presentation made in the frame of a course on "Culture and Identity" at Stockholm University for students at the level of French III. The presentation is about the political history of France after 1789.
Infinite loop superalgebras of the Dirac theory on the Euclidean Taub-NUT space
Creators: name: Cotaescu, Ion I.
name: Visinescu, Mihai
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The Dirac theory in the Euclidean Taub-NUT space gives rise to a large collection of conserved operators associated to genuine or hidden symmetries. They are involved in interesting algebraic structures as dynamical algebras or even infinite-dimensional algebras or superalgebras. One presents here the infinite-dimensional superalgebra specific to the Dirac theory in manifolds carrying the Gross-Perry-Sorkin monopole. It is shown that there exists an infinite-dimensional superalgebra that can be seen as a twisted loop superalgebra.
description: 16 pages, LaTeX, references added
The Fundamental Plane of Early Type Galaxies in Nearby Clusters from the WINGS Database
Creators: name: D'Onofrio, M.
name: Fasano, G.
name: Varela, J.
name: Bettoni, D.
name: Moles, M.
name: Kjaergaard, P.
name: Pignatelli, E.
name: Poggianti, B.
name: Dressler, D.
name: Cava, A.
name: Fritz, J.
name: Couch, W. J.
name: Omizzolo, A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: By exploting the data of three large surveys (WINGS, NFPS and SDSS), we present here a comparative analysis of the Fundamental Plane (FP hereafter) of the early-type galaxies (ETGs) belonging to 59 galaxy clusters in the redshift range $0.04
description: 51 pages, 18 figures, ApJ submitted
Real-time interactive 4D-STEM phase-contrast imaging from electron event representation data
Creators: name: Pelz, Philipp M.
name: Johnson, Ian
name: Ophus, Colin
name: Ercius, Peter
name: Scott, Mary C.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: The arrival of direct electron detectors (DED) with high frame-rates in the field of scanning transmission electron microscopy has enabled many experimental techniques that require collection of a full diffraction pattern at each scan position, a field which is subsumed under the name four dimensional-scanning transmission electron microscopy (4D-STEM). DED frame rates approaching 100 kHz require data transmission rates and data storage capabilities that exceed commonly available computing infrastructure. Current commercial DEDs allow the user to make compromises in pixel bit depth, detector binning or windowing to reduce the per-frame file size and allow higher frame rates. This change in detector specifications requires decisions to be made before data acquisition that may reduce or lose information that could have been advantageous during data analysis. The 4D Camera, a DED with 87 kHz frame-rate developed at Lawrence Berkeley National Laboratory, reduces the raw data to a linear-index encoded electron event representation (EER). Here we show with experimental data from the 4D Camera that linear-index encoded EER and its direct use in 4D-STEM phase contrast imaging methods enables real-time, interactive phase-contrast from large-area 4D-STEM datasets. We detail the computational complexity advantages of the EER and the necessary computational steps to achieve real-time interactive ptychography and center-of-mass differential phase contrast using commonly available hardware accelerators.
description: 11 pages
Calculation of absolute free energy of binding for theophylline and its analogs to RNA aptamer using nonequilibrium work values
Creators: name: Tanida, Yoshiaki
name: Ito, Masakatsu
name: Fujitani, Hideaki
Publisher: name: arXiv
Year: 2007
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The massively parallel computation of absolute binding free energy with a well-equilibrated system (MP-CAFEE) has been developed [H. Fujitani, Y. Tanida, M. Ito, G. Jayachandran, C. D. Snow, M. R. Shirts, E. J. Sorin, and V. S. Pande, J. Chem. Phys. ${\bf 123}$, 084108 (2005)]. As an application, we perform the binding affinity calculations of six theophylline-related ligands with RNA aptamer. Basically, our method is applicable when using many compute nodes to accelerate simulations, thus a parallel computing system is also developed. To further reduce the computational cost, the adequate non-uniform intervals of coupling constant $λ$, connecting two equilibrium states, namely bound and unbound, are determined. The absolute binding energies $ΔG$ thus obtained have effective linear relation between the computed and experimental values. If the results of two other different methods are compared, thermodynamic integration (TI) and molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) by the paper of Gouda $et al$ [H. Gouda, I. D. Kuntz, D. A. Case, and P. A. Kollman, Biopolymers ${\bf 68}$, 16 (2003)], the predictive accuracy of the relative values $ΔΔG$ is almost comparable to that of TI: the correlation coefficients (R) obtained are 0.99 (this work), 0.97 (TI), and 0.78 (MM-PBSA). On absolute binding energies meanwhile, a constant energy shift of $\sim$ -7 kcal/mol against the experimental values is evident. To solve this problem, several presumable reasons are investigated.
description: 23 pages including 6 figures
Trypanosoma (Megatrypanum) lainsoni Naiff & Barrett 2013, n. sp.
Creators: name: Naiff, Roberto Daibes
name: Barrett, Toby Vincent
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Protozoa
Euglenozoa
Kinetoplastea
Trypanosomatida
Trypanosomatidae
Trypanosoma
Trypanosoma lainsoni

description: Trypanosoma (Megatrypanum) lainsoni n. sp.
urn:lsid:zoobank.org:act: 7DA83760-8EA2-44D3-BBC4-8C98 64F948A6
Type host: Mesomys hispidus (Desmarest, 1817) (Rodentia: Echimyidae).
Type locality: municipality of Barcelos (00°S 64°W), state of Amazonas, Brazil.
Collector and date: Francisco Lima Santos, July 17, 1995.
Material examined: Hapantotypes, Giemsa-stained films of peripheral blood of experimentally infected laboratory mice: one epimastigote and 28 trypomastigotes, deposited in the Muséum National d 0 Histoire Naturelle, Paris, France (MNHN) under registration number MNHN ZS126.
Vector: Unknown.
Strain-code: IM-4156 (Laboratory designation).
Etymology: Specific name in recognition of Professor Ralph Lainson’s contributions to the study of protozoan parasites in the Amazonian fauna of Brazil.
Description (Figures 1–20; Table 1)
Bloodstream trypomastigotes (Figures 2–20) with a mean length of 33.4 including free flagellum and width 4–6. Free flagellum 4.0–10.0 (mean 7.7); undulating membrane well developed. Posterior end of the body long and pointed (Figures 17–20) or cuneiform (Figure 4); anterior end tapering to free flagellum. Nucleus oval, longitudinal or transverse near middle of body with a nuclear index (NI) of 0.7–1.4, but mainly 0.9–1.1; kinetoplast closer to nucleus than to posterior end with kinetoplastic index (KI) of 2.2–6.0, but mainly 0.9–1.1, and marginal. Other measurements are given in Table 1. A single bloodstream epimastigote was detected, with its nucleus in a strongly posterior position and NI of 0.4 (Figure 1).
description: Published as part of Naiff, Roberto Daibes & Barrett, Toby Vincent, 2013, Trypanosoma (Megatrypanum) lainsoni n. sp. from Mesomys hispidus (Rodentia: Echimyidae) in Brazil: trypomastigotes described from experimentally infected laboratory mice, pp. 1-5 in Parasite (Paris, France) (Paris, France) 20 on page 2, DOI: 10.1051/parasite/2013049, http://zenodo.org/record/12524160
An Electrophysiological Investigation Of Tamil Dative-Subject Constructions
Creators: name: Muralikrishnan, R.
Publisher: name: Zenodo
Year: 2011
Subjects: EEG
Auditory ERP study
Tamil
Dative-subjects
Default Agreement
Context Design
Animacy

description: Muralikrishnan (2011). PhD Dissertation, published as MPI Series in Human Cognitive and Brain Sciences, No.132. ISBN 978-3-941504-16-5
Demixing and orientational ordering in mixtures of rectangular particles
Creators: name: Heras, D. de las
name: Martinez-Raton, Y.
name: Velasco, E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Using scaled-particle theory for binary mixtures of two-dimensional hard particles with rotational freedom, we analyse the stability of nematic phases and the demixing phase behaviour of a variety of mixtures, focussing on cases where at least one of the components consists of hard rectangles or hard squares. A pure fluid of hard rectangles may exhibit, aside from the usual uniaxial nematic phase, an additional (tetratic) oriented phase, possessing two directors, which is the analogue of the biaxial or cubatic phases in three- dimensional fluids. There is computer simulation evidence that the tetratic phase might be stable with respect to phases with spatial order for rectangles with low aspect ratios. As hard rectangles are mixed with other particles not possessing stable tetratic order by themselves, the tetratic phase is destabilised, via a first- or second-order phase transition, to uniaxial nematic or isotropic phases; for hard rectangles of low aspect ratio tetratic order persists in a relatively large range of volume fractions. The order of these transitions depends on the particle geometry, dimensions and thermodynamic conditions of the mixture. The second component of the mixture has been chosen to be hard discs or disco-rectangles, the geometry of which is different from that of rectangles, leading to packing frustration and demixing behaviour, or simply rectangles of different aspect ratio. These mixtures may be good candidates for observing thermodynamically stable tetratic phases in monolayers of hard particles. Finally, demixing between fluid (isotropic--tetratic or tetratic--tetratic) phases is seen to occur in mixtures of hard squares of different sizes when the size ratio is sufficiently large.
description: 27 pages, 9 figures
Consideraciones en el ajuste del alcance resistivo en relés de distancia.pdf
Creators: name: Guaman Medina, Ruben
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 400805
subject: Electrical energy transmission, networks and systems

description: El artículo presenta los criterios y los cuidados que se deben tener en el ajuste del alcance resistivo de la protección de distancia para líneas de transmisión. Una falla externa a una línea puede provocar la operación de la protección de distancia de la propia línea por zona 1 debido al efecto del propio sistema. Se re-evalúa los criterios utilizados para el ajuste del alcance resistivo de las zonas de operación.
Low-energy quasilocalized excitations in structural glasses
Creators: name: Lerner, Edan
name: Bouchbinder, Eran
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Glassy solids exhibit a wide variety of generic thermomechanical properties, ranging from universal anomalous specific heat at cryogenic temperatures to nonlinear plastic yielding and failure under external driving forces, which qualitatively differ from their crystalline counterparts. For a long time, it has been believed that many of these properties are intimately related to nonphononic, low-energy quasilocalized excitations (QLEs) in glasses. Indeed, recent computer simulations have conclusively revealed that the self-organization of glasses during vitrification upon cooling from a melt leads to the emergence of such QLEs. In this Perspective Article, we review developments over the past three decades towards understanding the emergence of QLEs in structural glasses, and the degree of universality in their statistical and structural properties. We discuss the challenges and difficulties that hindered progress in achieving these goals, and review the frameworks put forward to overcome them. We conclude with an outlook on future research directions and open questions.
description: 24 pages, 15 figures, a Perspective Article
The F.A.S.T.-Model
Creators: name: Kretz, Tobias
name: Schreckenberg, Michael
Publisher: name: arXiv
Year: 2008
Subjects: subject: Multiagent Systems (cs.MA)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: A discrete model of pedestrian motion is presented that is implemented in the Floor field- and Agentbased Simulation Tool (F.A.S.T.) which has already been applicated to a variety of real life scenarios.
description: Extended version of proceedings contriution
Uganda's Agricultural Economy in Brief
Creators: name: Singleton, Carey B.
name: Singleton, Carey B.
Publisher: name: Unknown
Year: 1968
Subjects: Agricultural and Food Policy
Crop Production/Industries
International Relations/Trade
Land Economics/Use
Livestock Production/Industries

description: Excerpts from the report Summary: Uganda's major cash crop is coffee, for which the United States is the major customer, importing chiefly Robusta coffee. The second of the major cash crops is cotton. Together they account for approximately 65 percent of Uganda's exports and primarily determine the country's foreign exchange earnings. Agriculture, mainly subsistence-type farming, supports over 95 percent of the population, which is increasing at a rate of 2.5 percent annually. Uganda, a landlocked country, is largely self-sufficient in agriculture and food needs, and the country has no serious land shortage problems at this time. Agricultural activities account for about 60 percent of the gross domestic product and 80 percent of total exports. The major structural weakness of the Ugandan economy is its dependence on the world market prices of coffee and cotton. There is a pressing need for the establishment and development of agro-business enterprises to supply consumer products for the expanding domestic market.
Mrs. Joseph Hillman
Creators: name: Terry, H.
Publisher: name: Unknown
Year: 1870
Subjects: East Hampton
Photographs
Cabinet photographs
Portrait photographs
Portraits

description: This image shows a portrait of Mrs. Joseph Hillman. This photograph is part of a collection of photographs found in the ceiling of 140A Main Street, now 138, in East Hampton in 1970. This collection was donated by Joan Osborne in April 1995.
A Methodology for the Offline Evaluation of Recommender Systems in a User Interface with Multiple Carousels
Creators: name: Felicioni, Nicolò
name: Dacrema, Maurizio Ferrari
name: Cremonesi, Paolo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Information Retrieval (cs.IR)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Many video-on-demand and music streaming services provide the user with a page consisting of several recommendation lists, i.e. widgets or swipeable carousels, each built with a specific criterion (e.g. most recent, TV series, etc.). Finding efficient strategies to select which carousels to display is an active research topic of great industrial interest. In this setting, the overall quality of the recommendations of a new algorithm cannot be assessed by measuring solely its individual recommendation quality. Rather, it should be evaluated in a context where other recommendation lists are already available, to account for how they complement each other. This is not considered by traditional offline evaluation protocols. Hence, we propose an offline evaluation protocol for a carousel setting in which the recommendation quality of a model is measured by how much it improves upon that of an already available set of carousels. We report experiments on publicly available datasets on the movie domain and notice that under a carousel setting the ranking of the algorithms change. In particular, when a SLIM carousel is available, matrix factorization models tend to be preferred, while item-based models are penalized. We also propose to extend ranking metrics to the two-dimensional carousel layout in order to account for a known position bias, i.e. users will not explore the lists sequentially, but rather concentrate on the top-left corner of the screen.
Natural convection in two-dimensional irregular cavities
Creators: name: Fournier, Martin
Publisher: name: University of British Columbia
Year: 2010

description: Natural convection in two-dimensional irregular cavities was simulated by numerically solving the steady-state conservation equations written in terms of stream function, vorticity and temperature dependent variables and for a general orthogonal coordinate system. It was assumed that the Boussinesq approximations were valid, that the fluid was Newtonian and that the properties other than density were constant. The use of orthogonal coordinates and the above set of dependent variables was found to have several advantages over the use of Cartesian or non-orthogonal systems and the set of primitive dependent variables (velocities, pressure and temperature). The body-fitted orthogonal coordinate system was numerically generated by means of the weak constraint method of Ryskin and Leal [26], Special forms of the Wood and second-order vorticity boundary conditions were derived for a general two-dimensional body-fitted orthogonal coordinate system. Finite difference techniques were used to solve the resulting set of differential equations. The effects of the mapping characteristics, the vorticity boundary conditions and the finite difference grid size on the accuracy of the natural convection solution were investigated first. For the cavity geometries studied,, it was observed that, except for grid boundary conditions which led to undesirable grids, most combinations of grid and vorticity boundary conditions gave results of acceptable accuracy (relative error less than one percent) as long as a sufficiently fine grid size (28x28 or finer) was employed. The effects of the cavity geometry and the Rayleigh number on natural convection were investigated in Part II. It was found that increasing the Rayleigh number always acted to enhance both the natural convection circulation and the heat transfer rate, a result which was easily explained by examining the source term of the momentum equation. The effect of the cavity geometry was more complex but these results could also be interpreted by examining the influence of the cavity shape in impeding or enhancing fluid circulation and the opposing effects of the distance between isothermal walls on conductive and convective heat transfer. The possibility of using a similar numerical procedure to simulate a melting or a freezing process was investigated in Part III. Numerical predictions of the circulating flow in the liquid phase of an ice forming process were obtained by digitizing the photographic image of a real ice interface and using the true non-linear relationship between density and temperature for water at low temperature. The numerical results were in reasonable agreement with the flow visualization experiments carried out by Eckert [42].
Wave interference effect on polymer microstadium laser
Creators: name: Fang, W.
name: Cao, H.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We investigate the lasing modes in fully chaotic polymer microstadiums under optical pumping. The lasing modes are regularly spaced in frequency, and their amplitudes oscillate with frequency. Our numerical simulations reveal that the lasing modes are multi-orbit scar modes. The interference of partial waves propagating along the constituent orbits results in local maxima of quality factor at certain frequencies. The observed modulation of lasing mode amplitude with frequency results from the variation of quality factor, which provides the direct evidence of wave interference effect in open chaotic microcavities.
A Reliability-based Framework for Multi-path Routing Analysis in Mobile Ad-Hoc Networks
Creators: name: Caleffi, Marcello
name: Ferraiuolo, Giancarlo
name: Paura, Luigi
Publisher: name: arXiv
Year: 2008
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Unlike traditional routing procedures that, at the best, single out a unique route, multi-path routing protocols discover proactively several alternative routes. It has been recognized that multi-path routing can be more efficient than traditional one mainly for mobile ad hoc networks, where route failure events are frequent. Most studies in the area of multi-path routing focus on heuristic methods, and the performances of these strategies are commonly evaluated by numerical simulations. The need of a theoretical analysis motivates such a paper, which proposes to resort to the terminal-pair routing reliability as performance metric. This metric allows one to assess the performance gain due to the availability of route diversity. By resorting to graph theory, we propose an analytical framework to evaluate the tolerance of multi-path route discovery processes against route failures for mobile ad hoc networks. Moreover, we derive a useful bound to easily estimate the performance improvements achieved by multi-path routing with respect to any traditional routing protocol. Finally, numerical simulation results show the effectiveness of this performance analysis.
description: To appear on IJCNDS: International Journal of Communication Networks and Distributed Systems
Caso de Estudio ajuste del alcance resistivo de la protección de distancia.pdf
Creators: name: Guaman Medina, Ruben
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 400805
subject: Electrical energy transmission, networks and systems

description: Este artículo presenta un caso de estudio respecto del ajuste del alcance resistivo de las protecciones de distancia. Se analiza una falla en una red de 115 kV donde se registra la pérdida de selectividad de la protección de distancia debido a los criterios utilizados en el ajuste del alcance resistivo. El análisis es realizado en base a los registros oscilográficos capturados por las mismas protecciones
Multi-magnon bound states in the frustrated ferromagnetic 1D chain
Creators: name: Kecke, Lars
name: Momoi, Tsutomu
name: Furusaki, Akira
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We study a one-dimensional Heisenberg chain with competing ferromagnetic nearest-neighbor and antiferromagnetic next-nearest neighbor interactions in magnetic field. Starting from the fully polarized high-field state, we calculate the dispersions of the lowest-lying $n$-magnon excitations and the saturation field (n=2,3,4). We show that the lowest-lying excitations are always bound multi-magnon states with a total momentum of $π$ except for a small parameter range. We argue that bose condensation of the bound $n$ magnons leads to novel Tomonaga-Luttinger liquids with multi-polar correlations; nematic and triatic ordered liquids correspond to n=2 and n=3.
description: 5 pages, 3 figures
Role of beam propagation in Goos-Hänchen and Imbert-Fedorov shifts
Creators: name: Aiello, A.
name: Woerdman, J. P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Optics (physics.optics)
subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: We derive the polarization-dependent displacements parallel and perpendicular to the plane of incidence, for a Gaussian light beam reflected from a planar interface, taking into account the propagation of the beam. Using a classical-optics formalism we show that beam propagation may greatly affect both Goos-Hänchen and Imbert-Fedorov shifts when the incident beam is focussed.
description: 3 pages, 1 figure, submitted to Opt. Lett
Theodore Tilton in Bowtie
Creators: name: (:Unas)
Publisher: name: Unknown
Year: 1870
Subjects: East Hampton
Photographs
Cabinet photographs
Portrait photographs
Portraits

description: This image shows Theodore Tilton dressed in a suit and bowtie. This photograph is part of a collection of photographs found in the ceiling of 140A Main Street, now 138, in East Hampton in 1970. This collection was donated by Joan Osborne in April 1995.
The Sleep-Fertility Link: Unravelling the Importance of Quality Rest
Creators: name: Ramya Koneru* and Vinutha U Muktamath1
Publisher: name: The Science world a Monthly e magazine
Year: 2023

description: Sleep is a physiological process that can restore the depleted physical and mental energy. Irregular sleep-wake syndrome, sleep interruption, overly-long or short sleeping time, hypoxia or circadian disorder were the sleeping problems. Variation in hormonal levels in women, especially during menstrual cycle or pregnancy may have typical effect on sleep cycle. Nevertheless, the studies report that sleep plays a significant role in women undergoing IVF treatment, as insufficient sleep or disturbed sleep may be detrimental during IVF treatment. As infertility is globally recognized psychological distress, it deteriorates the mental wellbeing of intended parents. The infertility treatments are emotionally debilitating, and requires multiple attempts to achieve a pregnancy. Thus, based on research evidence health professionals suggest healthy sleeping pattern for successful IVF attempts.
Unitarity analysis of a non-Abelian gauge invariant action with a mass
Creators: name: Dudal, David
name: Vandersickel, Nele
name: Verschelde, Henri
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In previous work done by us and coworkers, we have been able to construct a local, non-Abelian gauge invariant action with a mass parameter, based on the nonlocal gauge invariant mass dimension two operator F1/D^2F. The renormalizability of the resulting action was proven to all orders of perturbation theory, in the class of linear covariant gauges. We also discussed the perturbative equivalence of the model with ordinary massless Yang-Mills gauge theories when the mass is identically zero. Furthermore, we pointed out the existence of a BRST symmetry with corresponding nilpotent charge. In this paper, we study the issue of unitarity of this massive gauge model. Firstly, we provide a short review how to discuss the unitarity making use of the BRST charge. Afterwards we make a detailed study of the most general version of our action, and we come to the conclusion that the model is not unitary, as we are unable to remove all the negative norm states from the physical spectrum in a consistent way.
description: 36 pages
Quasi Exactly Solvable Difference Equations
Creators: name: Sasaki, Ryu
Publisher: name: arXiv
Year: 2007
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Several explicit examples of quasi exactly solvable `discrete' quantum mechanical Hamiltonians are derived by deforming the well-known exactly solvable Hamiltonians of one degree of freedom. These are difference analogues of the well-known quasi exactly solvable systems, the harmonic oscillator (with/without the centrifugal potential) deformed by a sextic potential and the 1/sin^2x potential deformed by a cos2x potential. They have a finite number of exactly calculable eigenvalues and eigenfunctions.
description: LaTeX with amsfonts, no figure, 17 pages, a few typos corrected, a reference renewed, 3/2 pages comments on hermiticity added
A Survey of Agriculture in Ethiopia
Creators: name: Sabatini, Omero
name: Samuel, Louise N.
name: Sabatini, Omero
name: Samuel, Louise N.
Publisher: name: Unknown
Year: 1969
Subjects: Agricultural and Food Policy
Crop Production/Industries
International Relations/Trade
Labor and Human Capital
Livestock Production/Industries

description: Excerpts from the report Summary: Subsistence farming is likely to dominate Ethiopian agriculture for many years, but the foundation for modernization is being laid in several areas by the Government. Financial and technical aid, primarily from the United States but also from the United Nations and other sources, is contributing significantly to the Government's programs to expand, diversify, and modernize farm production. These programs include: • Establishment of agricultural research institutions and of an extension service. • Formation of farm cooperatives. • Promotion of cultivation of cash crops by small farmers and of large-scale commercial farming. • Improvement of livestock management. Coffee accounts for 50 to 60 percent of Ethiopia's total exports, and the United States--Ethiopia' s leading foreign agricultural market--imports 65 to 75 percent of the coffee. The main grains grown are teff, sorghum, barley, and corn. Other crops, also grown mainly for domestic consumption, include sugarcane, cotton, and chat (a mild stimulant). Cotton output is expanding rapidly, but Ethiopia must still import lint for its mills.
Questionnaire
Creators: name: Azevedo, Ana
name: Sousa Pinto, Agostinho
name: Curado Malta, Mariana
Publisher: name: Zenodo
Year: 2019

description: This dataset belongs to the process of defining the curriculum of a e-business master course that opened in 2018 in the Business School of the Polytechnic of Porto (ISCAP), Portugal.

With the aim of designing a course that corresponded as much as possible to the needs of the labour market and incorporating the expectations and concerns of potential employers and future students, the authors carried out 1) an inquiry, doing interviews to potential employers, and 2) a survey, applying a questionnaire to ISCAP final year students of some after working hours degrees, and to graduate students who are already in the labour market.

This file is the questionnaire.
Three-Nucleon Continuum by means of the Hyperspherical Adiabatic Method
Creators: name: Barletta, P.
name: Kievsky, A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: This paper investigates the possible use of the Hyperspherical Adiabatic basis in the description of scattering states of a three-body system. In particular, we analyze a 1+2 collision process below the three-body breakup. The convergence patterns for the observables of interest are analyzed by comparison to a unitary equivalent Hyperspherical Harmonic expansion. Furthermore, we compare and discuss two different possible choices for describing the asymptotic configurations of the system, related to the use of Jacobi or hyperspherical coordinates. In order to illustrate the difficulties and advantages of the approach two simple numerical applications are shown in the case of neutron-deuteron scattering at low energies using s-wave interactions. We found that the optimization driven by the Hyperspherical Adiabatic basis is not as efficient for scattering states as in bound state applications.
description: 29 pages, 5 figures, accepted for publication in Few-Body Systems (in press)
Filtering the fiber of the pinch map
Creators: name: Gray, Brayton
Publisher: name: arXiv
Year: 2008
Subjects: subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 55P99, 55Q20, 55Q25

description: A new type of Hopf invariant is described for the fiber of the pinch map from the mapping cone of a map from A to X onto to the suspension of A; this is then used to study the boundary map in the fibration sequence of Cohen, Moore and Neisendorfer in the case that the mapping cone is an odd dimensional Moore space. The components of the boundary map are then shown to be compatible with Hopf invariants and a filtered splitting of the loops on the fiber is obtained.
description: This is the version published by Geometry & Topology Monographs on 22 2008
Relativistic Tennis with Photons: Demonstration of Frequency Upshifting by a Relativistic Flying Mirror through Two Colliding Laser Pulses
Creators: name: Kando, M.
name: Fukuda, Y.
name: Pirozhkov, A. S.
name: Ma, J.
name: Daito, I.
name: Chen, L. -M.
name: Esirkepov, T. Zh.
name: Ogura, K.
name: Homma, T.
name: Hayashi, Y.
name: Kotaki, H.
name: Sagisaka, A.
name: Mori, M.
name: Koga, J. K.
name: Daido, H.
name: Bulanov, S. V.
name: Kimura, T.
name: Kato, Y.
name: Tajima, T.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: Since the advent of chirped pulse amplification1 the peak power of lasers has grown dramatically and opened the new branch of high field science, delivering the focused irradiance, electric fields of which drive electrons into the relativistic regime. In a plasma wake wave generated by such a laser, modulations of the electron density naturally and robustly take the shape of paraboloidal dense shells, separated by evacuated regions, moving almost at the speed of light. When we inject another counter-propagating laser pulse, it is partially reflected from the shells, acting as relativistic flying (semi-transparent) mirrors, producing an extremely time-compressed frequency-multiplied pulse which may be focused tightly to the diffraction limit. This is as if the counterstreaming laser pulse bounces off a relativistically swung tennis racket, turning the ball of the laser photons into another ball of coherent X-ray photons but with a form extremely relativistically compressed to attosecond and zeptosecond levels. Here we report the first demonstration of the frequency multiplication detected from the reflection of a weak laser pulse in the region of the wake wave generated by the driver pulse in helium plasma. This leads to the possibility of very strong pulse compression and extreme coherent light intensification. This Relativistic Tennis with photon beams is demonstrated leading to the possibility toward reaching enormous electromagnetic field intensification and finally approaching the Schwinger field, toward which the vacuum nonlinearly warps and eventually breaks, producing electron-positron pairs.
description: 17 pages, 5 figures
The mass content of the Sculptor dwarf spheroidal galaxy
Creators: name: Battaglia, G.
name: Helmi, A.
name: Tolstoy, E.
name: Irwin, M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a new determination of the mass content of the Sculptor dwarf spheroidal galaxy, based on a novel approach which takes into account the two distinct stellar populations present in this galaxy. This method helps to partially break the well-known mass-anisotropy degeneracy present in the modelling of pressure-supported stellar systems.
description: 6 pages, 3 figures. To appear in the proceedings of IAU Symposium 254 "The Galaxy disk in a cosmological context", Copenhagen, June 2008
Detection of subthreshold pulses in neurons with channel noise
Creators: name: Chen, Yong
name: Yu, Lianchun
name: Qin, Shao-Meng
Publisher: name: arXiv
Year: 2007
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: Subcellular Processes (q-bio.SC)
subject: FOS: Biological sciences

description: Neurons are subject to various kinds of noise. In addition to synaptic noise, the stochastic opening and closing of ion channels represents an intrinsic source of noise that affects the signal processing properties of the neuron. In this paper, we studied the response of a stochastic Hodgkin-Huxley neuron to transient input subthreshold pulses. It was found that the average response time decreases but variance increases as the amplitude of channel noise increases. In the case of single pulse detection, we show that channel noise enables one neuron to detect the subthreshold signals and an optimal membrane area (or channel noise intensity) exists for a single neuron to achieve optimal performance. However, the detection ability of a single neuron is limited by large errors. Here, we test a simple neuronal network that can enhance the pulse detecting abilities of neurons and find dozens of neurons can perfectly detect subthreshold pulses. The phenomenon of intrinsic stochastic resonance is also found both at the level of single neurons and at the level of networks. At the network level, the detection ability of networks can be optimized for the number of neurons comprising the network.
description: 14 pages, 9 figures
Continuous spouted bed process for sulphur-coating urea
Creators: name: Tsai, Bobby S. E.
Publisher: name: University of British Columbia
Year: 2010

description: Sulphur-coated urea is a controlled-release, nitrogen fertilizer which has proven to be successful commercially. Current production technology used by Canadian Industries Ltd. and other firms is based on the Tennessee Valley Authority rotary drum process. This process is mechanically complex and the sulphur coated urea requires an additional wax coat to achieve the desired slow-release properties. By contrast, the spouted bed coating process developed at UBC promises to be mechanically simpler. Afer some initial difficulties, successful continuous coating was achieved in the present thesis project by means of a modified laboratory spouted bed facility. The facility can produce 9.6 kg/h of sulphur-coated urea for up to 3 hours. Coating is performed in a spouted bed, which consists of a cylindrical column (0.154 m I.D. by 0.91 m high) and a 60° conical base. Urea is fed into the bed through a feed tube inserted into the bed annulus. Molten sulphur is sprayed through a nozzle into the base of the bed co-currently with the spouting air. Product is discharged from slots around the perimeter of the spouting column and collected in a product cooler. Particulates from the off-gas leaving the spouted bed and the cooler are removed by a cyclone and water scrubber. Product quality is determined by a rapid dissolution test developed at UBC and a 7-day dissolution test developed by the TVA and modified at UBC. The product quality is found to depend on the bed temperature and the bed depth. In the range of 55 to 90°C the dissolution value decreases up to a bed temperature of approximately 80°C and then increases again. Coating performed at two different bed depths, 0.15 m and 0.25 m, show that superior product quality is achieved with the shallower bed. A set of optimal coating conditions is found: coating temperature of 80°C, bed depth of 0.15 m, spouting air flow rate of 0.65 m³/min and atomizing air pressure of 208 kPa. Under these conditions, modified 7-day dissolution values of about 30% are found for the UBC product compared to 88% for the CIL product with similar sulphur content and no wax. When coated with 30 wt% or more sulphur, the UBC product is able to meet the industrial standard of 25% of urea dissolved in 7 days.
Post-selective two-photon interference from a continuous non-classical stream of photons emitted by a quantum dot
Creators: name: Patel, R. B.
name: Bennett, A. J.
name: Cooper, K.
name: Atkinson, P.
name: Nicoll, C. A.
name: Ritchie, D. A.
name: Shields, A. J.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We report an electrically driven semiconductor single photon source capable of emitting photons with a coherence time of up to 400 ps under fixed bias. It is shown that increasing the injection current causes the coherence time to reduce and this effect is well explained by the fast modulation of a fluctuating environment. Hong-Ou-Mandel type two-photon interference using a Mach-Zehnder interferometer is demonstrated using this source to test the indistinguishability of individual photons by post-selecting events where two photons collide at a beamsplitter. Finally, we consider how improvements in our detection system can be used to achieve a higher interference visibility.
description: 4 pages, 3 figures: for publication in Phys. Rev. Lett
Modelling long-term trends in lunar exposure to the Earth's plasmasheet
Creators: name: Hapgood, Mike
Publisher: name: arXiv
Year: 2007
Subjects: subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: This paper shows how the exposure of the Moon to the Earth's plasmasheet is subject to decadal variations due to lunar precession. The latter is a key property of the Moon's apparent orbit around the Earth - the nodes of that orbit precess around the ecliptic, completing one revolution every 18.6 years. This precession is responsible for a number of astronomical phenomena, e.g. the year to year drift of solar and lunar eclipse periods. It also controls the ecliptic latitude at which the Moon crosses the magnetotail and thus the number and duration of lunar encounters with the plasmasheet. This paper presents a detailed model of those encounters and applies it to the period 1960 to 2030. This shows that the total lunar exposure to the plasmasheet will vary from 10 hours per month at a minimum of the eighteen-year cycle rising to 40 hours per month at the maximum. These variations could have a profound impact on the accumulation of charge due plasmasheet electrons impacting the lunar surface. Thus we should expect the level of lunar surface charging to vary over the eighteen-year cycle. The literature contains reports that support this: several observations made during the cycle maximum of 1994-2000 are attributed to bombardment and charging of the lunar surface by plasmasheet electrons. Thus we conclude that lunar surface charging will vary markedly over an eighteen-year cycle driven by lunar precession. It is important to interpret lunar environment measurements in the context of this cycle and to allow for the cycle when designing equipment for deployment on the lunar surface. This is particularly important in respect of developing plans for robotic exploration on the lunar surface during the next cycle maximum of 2012-19.
description: 20 pages, 6 figures, re-submitted to Annales Geophysicae, for an animated version of Figure 1 see http://uk.geocities.com/mike.hapgood@btinternet.com/moon_movie_6.gif