86,576 research outputs found
Model-independent extraction of {pipe}Vtq{pipe} matrix elements from top-quark measurements at hadron colliders
No full textCurrent methods to extract the quark-mixing matrix element {pipe}Vtb{pipe} from single-top-production measurements assume that {pipe}Vtb{pipe}>>{pipe}Vtd{pipe},{pipe}Vts{pipe}: top quarks decay into b quarks with 100 % branching fraction, s-channel single-top production is always accompanied by a b quark and initial-state contributions from d and s quarks in the t-channel production of single top quarks are neglected. Triggered by a recent measurement of the ratio, 0. 90 ±0. 04 performed by the D0 collaboration, we consider a {pipe}Vtb{pipe} extraction method that takes into account non zero d- and s-quark contributions both in production and decay. We propose a strategy that allows to extract consistently and in a model-independent way the quark-mixing matrix elements {pipe}Vtd{pipe}, {pipe}Vts{pipe}, and {pipe}Vtb{pipe} from the measurement of R and from single-top measured event yields. As an illustration, we apply our method to the Tevatron data using a CDF analysis of the measured single-top event yield with two jets in the final state, one of which is identified as a b-quark jet. We constrain the {pipe}Vtq{pipe} matrix elements within a four-generation scenario by combining the results with those obtained from direct measurements in flavor physics and determine the preferred range for the top-quark decay width within different scenarios. © 2012 Springer-Verlag / Società Italiana di Fisica
The solubility and oxidation state of nickel in silicate melt at low oxygen fugacities: Results using a mechanically assisted equilibration technique
No full textThe solubility of Ni in a silicate melt has been measured using a new, mechanically assisted equilibration technique over a wide range of controlled ƒO2 values. The melt composition corresponds to the 1 atm eutectic in the system CaAl2Si2O8-CaMgSi2O6 + 10 wt% CaO. The experiments were performed at 1300°C and over an ƒO2 range of 10−8.5 to 10−13.75, and over a temperature range of 1270 to 1390°C at a constant gas mixing ratio ( ). The experiment consists of a sample of melt contained within a crucible of Ni metal and held in a 1 atm gas mixing furnace. A Ni spindle is entered into the sample from above and continuously rotated at a constant angular velocity using a viscometer head. The stirring of the sample serves to accelerate the approach to equilibrium between the liquid sample and the metal crucible (and spindle). This arrangement allows relatively rapid equilibration of Ni content following changes to higher or lower ƒO2 values. Samples of the melt may be taken at any time for analysis and thus the equilibrium solubility of Ni in the silicate melt may be determined from unambiguous experimental reversals. The Ni contents of samples, analysed both by INAA and by ICP-AES, range from 25 to 5300 ppm.
The data presented in this paper indicate that the oxidation state of Ni in the investigated melt is Ni2+ over the entire range of ƒO2 investigated. This conclusion contrasts with recent reports in the literature of an inflection in the ƒO2 dependence of Ni solubility, which has been interpreted as solution of neutral Ni at low ƒO2 (Morse et al., 1991; Colson, 1992; Ehlers et al., 1992). We also present data for the temperature dependence of Ni solubility in the investigated melt. The solubility decreases with increasing temperature at constant ƒO2. The present results are in good agreement with the metal-loop-equilibration experiments reported by Holzheid et al. (1994)
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Rapport I.13 Comparaison de résultats théoriques et expérimentaux pour une roue de pompe hélico-centrifuge
No full textThe paper gives the comparison between experimental measurements and theoretical flow calculations in an open mixed flow impeller.
Various measurements from nominal flow Qn to partial flow .5 Qn show the velocity distribution in the impeller channels and boundary unsteady pressures around the impeller on the casing inner surface.
Flow calculations from a quasi-tridimensional flow model are compared to measured values. The deviation may be considered as acceptable. The front casing unsteady pressure leads to an estimate of the energy exchange between the impeller main flow and the boundary flow initiated in the gap between the impeller blades and the front casing.L'étude présentée est une analyse comparée de résultats théoriques et expérimentaux obtenus pour une roue ouverte de pompe hélico-centrifuge.
Les diverses mesures menées depuis le débit nominal Qn jusqu'à un débit partiel de 0,5 Qn mettent en évidence l'évolution du champ des vitesses et des pressions pariétales instationnaires en ceinture, ainsi que l'apparition des recirculations. La comparaison de ces mesures à des données théoriques, obtenues à partir d'un programme de calcul quasi-tridimensionnel montre une concordance acceptable.
De même, l'analyse des pressions pariétales instationnaires donne une image des échanges d'énergie roue-fluide en ceinture.Huang X., Rieutord Émile, Spettel F., Lapray Jean-François. Rapport I.13 Comparaison de résultats théoriques et expérimentaux pour une roue de pompe hélico-centrifuge. In: Machines hydrauliques. Conception et exploitation. Développements récents et Applications aux différents secteurs industriels. Vingtièmes journées de l'hydraulique. Lyon, 4-6 avril 1989. Tome 1, 1989
[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
Model-independent extraction of |V_{tq}| matrix elements from top-quark measurements at hadron colliders
No full textCurrent methods to extract the quark-mixing matrix element from single-top production measurements assume that : top quarks decay into quarks with 100% branching fraction, s-channel single-top production is always accompanied by a quark and initial-state contributions from and quarks in the -channel production of single top quarks are neglected. Triggered by a recent measurement of the ratio performed by the D0 collaboration, we consider a extraction method that takes into account non zero d- and s-quark contributions both in production and decay. We propose a strategy that allows to extract consistently and in a model-independent way the quark mixing matrix elements , , and from the measurement of and from single-top measured event yields. As an illustration, we apply our method to the Tevatron data using a CDF analysis of the measured single-top event yield with two jets in the final state one of which is identified as a -quark jet. We constrain the matrix elements within a four-generation scenario by combining the results with those obtained from direct measurements in flavor physics and determine the preferred range for the top-quark decay width within different scenarios
John F. Kennedy telegram to Roosevelt
No full textJersey Homesteads (later the Borough of Roosevelt) was established in the 1930s as an agro-industrial cooperative community. It was established specifically for urban Jewish garment workers, many of whom had emigrated from Europe. President John F. Kennedy sent a telegram to the citizens of Roosevelt, New Jersey, apologizing for not being able to attend the memorial dedication in honor of former President Franklin Delano Roosevelt. (Jersey Homesteads became Roosevelt in 1945 in honor of the president.) President Kennedy expressed his gratitude to the people of Roosevelt for constructing the memorial, and commented that it will serve as a constant reminder of Roosevelt's good works
Logarithmic variance profiles and the corresponding f-1 spectra of temperature fluctuations in turbulent Rayleigh-Bénard convection
No full textWe report experimental results for the temperature variance 2(z) and the corresponding frequency spectra P(f) in turbulent Rayleigh-Bénard convection (RBC) in a cylindrical sample of aspect ratioT= D/L = 1:00 (D = 1:12 m is the diameter and L = 1:12 m the height). The measurements were conducted in the Rayleigh-number range 1011 < Ra < 1:35 1014 and Pr ' 0:8. For Ra = 1:35x1014, 2(z) could be described well by a logarithmic dependence on the vertical position z in a range of z 1 < z < z 2 with z 1 ' 70 and z 2 = 0:1L. Here L=(2Nu) is the thickness of a thin thermal sublayer adjacent to the horizontal plate where the heat flux (denoted by the Nusselt number Nu) is carried mostly by thermal diffusion. In the log layer, we found that the temperature spectra had a significant frequency range over which P(f) f with close to 1. As Ra decreased, increased so that the log layer became thinner. At Ra = 2:05 1011, z 2 < z 1 and therefore there was no range for a log layer. Correspondingly, the temperature spectrum near the horizontal plate did not have the f1 scaling form either
Maine author Franklin F. Gould recalls his first glimpse of the outside world
No full textMaine author Franklin F. Gould recalls his first glimpse of the outside world as he relates how, as a young farm boy in the late 1800\u27s, he drove his father\u27s horses on an errand to an icebound river
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