22,407 research outputs found
Dr. Glendon Swarthout
Hosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Reynolds number effect on turbulent drag reduction
An analytic relationship that predicts the Reynolds number effect on turbulent drag reduction by active means is developed in analogy with riblets. It is applicable to all control techniques whose action result in an upward shift ∆B of the logarithmic region of the turbulent velocity profile. In particular, we use it to address the Re-effect affecting streamwise-traveling waves of spanwise wall velocity \cite{quadrio-ricco-viotti-2009}, aided by a new large dataset of Direct Numerical Simulations of turbulent channel flows at increasing Re. The main outcome of this study is that the control-induced upward-shift of the logarithmic region ∆B does not vary with Re along a large part of the wave parameter space, also where high drag reduction is achieved. Here, the analytical relationship allows to extrapolate low-Re drag reduction information to high-Re flows. In the narrow regions where ∆B does vary with Re, an additional Re-effect is deemed to exist, which depends on the present control technique only and which is investigated with a three-dimensional phase conditional averaging procedure
Search for exclusive b → u transitions in hadronic decays of B mesons involving Ds+ and Ds*+ mesons
complete author list:
Alexander J.; Bebek C.; Berkelman K.; Bloom K.; Browder T.; Cassel D.; Cho H.; Coffman D.; Drell P.; Ehrlich R.; Garcia-Sciveres M.; Geiser B.; Gittelman B.; Gray S.; Hartill D.; Heltsley B.; Jones C.; Jones S.; Kandaswamy J.; Katayama N.; Kim P.; Kreinick D.; Ludwig G.; Masui J.; Mevissen J.; Mistry N.; Ng C.; Nordberg E.; Patterson J.; Peterson D.; Riley D.; Salman S.; Sapper M.; Würthwein F.; Avery P.; Freyberger A.; Rodriguez J.; Stephens R.; Yelton J.; Cinabro D.; Henderson S.; Kinoshita K.; Liu T.; Saulnier M.; Wilson R.; Yamamoto H.; Bergfeld T.; Eisenstein B.; Gollin G.; Ong B.; Palmer M.; Selen M.; Thaler J.; Sadoff A.; Ammar R.; Ball S.; Baringer P.; Bean A.; Besson D.; Coppage D.; Copty N.; Davis R.; Hancock N.; Kelly M.; Kwak N.; Lam H.; Kubota Y.; Lattery M.; Nelson J.; Patton S.; Perticone D.; Poling R.; Savinov V.; Schrenk S.; Wang R.; Alam M.; Kim I.; Nemati B.; O'Neill J.; Severini H.; Sun C.; Zoeller M.; Crawford G.; Daubenmier C.; Fulton R.; Fujino D.; Gan K.; Honscheid K.; Kagan H.; Kass R.; Lee J.; Malchow R.; Morrow F.; Skovpen Y.; Sung M.; White C.; Butler F.; Fu X.; Kalbfleisch G.; Ross W.; Skubic P.; Snow J.; Wang P.; Wood M.; Brown D.; Fast J.; McIlwain R.; Miao T.; Miller D.; Modesitt M.; Payne D.; Shibata E.; Shipsey I.; Wang P.; Battle M.; Ernst J.; Kwon Y.; Roberts S.; Thorndike E.; Wang C.; Dominick J.; Lambrecht M.; Sanghera S.; Shelkov V.; Skwarnicki T.; Stroynowski R.; Volobouev I.; Wei G.; Zadorozhny P.; Artuso M.; He D.; Goldberg M.; Horwitz N.; Kennett R.; Mountain R.; Moneti G.; Muheim F.; Mukhin Y.; Playfer S.; Rozen Y.; Stone S.; Thulasidas M.; Vasseur G.; Zhu G.; Bartelt J.; Csorna S.; Egyed Z.; Jain V.; Akerib D.; Barish B.; Chadha M.; Chan S.; Cowen D.; Eigen G.; Miller J.; O'Grady C.; Urheim J.; Weinstein A.; Acosta D.; Athanas M.; Masek G.; Paar H.; Gronberg J.; Kutschke R.; Menary S.; Morrison R.; Nakanishi S.; Nelson H.; Nelson T.; Richman J.; Ryd A.; Tajima H.; Schmidt D.; Sperka D.; Witherell M.; Procario M.; Yang S.; Balest R.; Cho K.; Daoudi M.; Ford W.; Johnson D.; Lingel K.; Lohner M.; Rankin P.; Smith J.; Alexander J.; Alexander J.P
Similarities between 2D and 3D convection for large Prandtl number
Using direct numerical simulations of Rayleigh-B\'enard convection (RBC), we perform a comparative study of the spectra and fluxes of energy and entropy for large and infinite Prandtl numbers in two (2D) and three (3D) dimensions. We observe close similarities between the 2D and 3D RBC, in particular the kinetic energy spectrum , and the entropy spectrum exhibits a dual branch with a dominant spectrum. We showed that the dominant Fourier modes in the 2D and 3D flows are very close
Transition to turbulence in a qblique shock-wave/boundary-layer interaction at M=15
Direct numerical simulations are carried out for different forcing techniques to trigger transition during the interaction between an oblique shock-wave and a laminar boundary-layer at M = 1.5. Three forcing methods are used: a) forcing of oblique unstable modes, whose shape and behaviour are determined by the local linear stability theory, b) broadband free-stream acoustic disturbances, and c) a cold plasma flow control device. While the oblique-mode breakdown is dominant for low-amplitude forcing, long streaky structures drive the transition process in a high-amplitude disturbance environment. LES are also performed on the experimental setup by the Institute of Theoretical and Applied Mechanics (ITAM) from Novosibirsk State University with cold plasma actuation. As well as the disturbance type, the effect of Reynolds number and forcing amplitude will be investigated
The time-dependent supersymmetric configurations in M-theory and matrix models
In this Letter, we study the half-supersymmetric time-dependent configurations in M-theory and their matrix models. We find a large class of I I D supergravity solutions, which keeps sixteen supersymmetries. Furthermore, we investigate the isometrics of these configurations and show that in general these configurations have no supernumerary supersymmetry. And also we define the matrix models in these backgrounds following discrete light-cone quantization (DLCQ) prescription. (c) 2005 Elsevier B.V. All rights reserved.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000234727200043&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, MultidisciplinarySCI(E)38ARTICLE2-3393-39863
Overview of the author identification task at PAN 2014
The author identification task at PAN-2014 focuses on author verification. Similar to PAN-2013 we are given a set of documents by the same author along with exactly one document of questioned authorship, and the task is to determine whether the known and the questioned documents are by the same author or not. In comparison to PAN-2013, a significantly larger corpus was built comprising hundreds of documents in four natural languages (Dutch, English, Greek, and Spanish) and four genres (essays, reviews, novels, opinion articles). In addition, more suitable performance measures are used focusing on the accuracy and the confidence of the predictions as well as the ability of the submitted methods to leave some problems unanswered in case there is great uncertainty. To this end, we adopt the c@1 measure, originally proposed for the question answering task. We received 13 software submissions that were evaluated in the TIRA framework. Analytical evaluation results are presented where one language-independent approach serves as a challenging baseline. Moreover, we continue the successful practice of the PAN labs to examine meta-models based on the combination of all submitted systems. Last but not least, we provide statistical significance tests to demonstrate the important differences between the submitted approaches
Convective Ripening and Rainfall
This paper discusses the evolution of the droplet size distribution for a liquid-in-gas aerosol contained in a Rayleigh-B\'enard cell. It introduces a non-collisional model for broadening the droplet size distribution, termed \lq convective ripening'. The paper also considers the initiation of rainfall from ice-free cumulus clouds. It is argued that while collisional mechanisms cannot explain the production of rain from clouds with water droplet diameters of , the non-collisional convective ripening mechanism gives a much faster route to increasing the size of the small fraction of droplets that grow into raindrops
Observation of the Ξ − b → J /ψΛK − decay
© 2017 The Author(s) The observation of the decay Ξb−→J/ψΛK−is reported, using a data sample corresponding to an integrated luminosity of 3fb−1, collected by the LHCb detector in pp collisions at centre-of-mass energies of 7 and 8TeV. The production rate of Ξb−baryons detected in the decay Ξb−→J/ψΛK−is measured relative to that of Λb0baryons using the decay Λb0→J/ψΛ. Integrated over the b-baryon transverse momentum pT<25GeV/c and rapidity 2.0<y<4.5, the measured ratio is [Formula presented][Formula presented]=(4.19±0.29 (stat)±0.15 (syst))×10−2, where fΞb−and fΛb0are the fragmentation fractions of b→Ξb−and b→Λb0transitions, and B represents the branching fraction of the corresponding b-baryon decay. The mass difference between Ξb−and Λb0baryons is measured to be M(Ξb−)−M(Λb0)=177.08±0.47 (stat)±0.16 (syst)MeV/c2
Mean field model for turbulence transition in plane Poiseuille flow
In the pipe flow model of Dwight Barkley the main idea is to model pipe flow as an excitable, bistable medium. Using a one-dimensional FitzHugh-Nagumo-type reaction-advection-diffusion system with two variables the model captures qualitatively a surprising number of features of the turbulence transition in pipe flow. Motivated by this success, we here describe a derivation of a set of two 1+1-dimensional coupled differential equations for the closely related system of plane Poiseuille flow from the Navier-Stokes equation. The model contains terms for the production of turbulent kinetic energy, its transfer between the modes and its dissipation by viscous terms. The model shows a bifurcation to a non-trivial state and reflects some of the complex dynamics observed in direct numerical simulations
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