112 research outputs found
Rheology of Granular Rafts
Rheology of macroscopic particle-laden interfaces, called "Granular Rafts"
has been experimentally studied, in the simple shear configuration. The
shear-stress relation obtained from a classical rheometer exhibits the same
behavior as a Bingham fluid and the viscosity diverges with the surface
fraction according to evolutions similar to 2D suspensions. The velocity field
of the particles that constitute the granular raft has been measured in the
stationary state. These measurements reveal non-local rheology similar to dry
granular materials. Close to the walls of the rheometer cell, one can observe
regions of large local shear rate while in the middle of the cell a quasistatic
zone exists. This flowing region, characteristic of granular matter, is
described in the framework of an extended kinetic theory showing the evolution
of the velocity profile with the imposed shear stress. Measuring the
probability density functions of the elementary strains, we provide evidence of
a balance between positive and negative elementary strains. This behavior is
the signature of a quasistatic region inside the granular raft.Comment: 5 pages, 4 figure
Comparing all-optical switching in synthetic-ferrimagnetic multilayers and alloys
We present an experimental and theoretical investigation of all-optical
switching by single femtosecond laser pulses. Our experimental results
demonstrate that, unlike rare earth-transition metal ferrimagnetic alloys,
Pt/Co/[Ni/Co]/Gd can be switched in the absence of a magnetization
compensation temperature, indicative for strikingly different switching
conditions. In order to understand the underlying mechanism, we model the
laser-induced magnetization dynamics in Co/Gd bilayers and GdCo alloys on an
equal footing, using an extension of the microscopic three-temperature model to
multiple magnetic sublattices and including exchange scattering. In agreement
with our experimental observations, the model shows that Co/Gd bilayers can be
switched for an arbitrary thickness of the Co layer, i.e, even far away from
compensating the total Co and Gd magnetic moment. We identify the switching
mechanism in Co/Gd bilayers as a front of reversed Co magnetization that
nucleates at the Co/Gd interface and propagates through the Co layer driven by
exchange scattering.Comment: Published versio
Measurement of electroweak parameters from hadronic and leptonic decays of the Z 0
We have studied the reactions e + e â âhadrons, e + e â , ÎŒ + ÎŒ â and Ï + Ï â , in the energy range 88.2 GeV. A total luminosity of 5.5 pb â1 , corresponding to approximately 115000 hadronic and 10000 leptonic Z 0 decays, has been recorded with the L3 detector. From a simultaneous fit to all of our measured cross section data, we obtain assuming lepton universality:Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47890/1/10052_2005_Article_BF01475788.pd
ĐŁĐżŃĐ°ĐČĐ»Đ”ĐœĐžĐ” ŃĐžŃŃĐ”ĐŒĐŸĐč ŃлДĐșŃŃĐŸŃ ĐžĐŒĐžŃĐ”ŃĐșĐŸĐč Đ·Đ°ŃĐžŃŃ ĐŒĐ°ĐłĐžŃŃŃĐ°Đ»ŃĐœĐŸĐłĐŸ ĐłĐ°Đ·ĐŸĐżŃĐŸĐČĐŸĐŽĐ° ĐČ ŃŃĐ»ĐŸĐČĐžŃŃ ĐČĐ”ŃĐœĐŸĐč ĐŒĐ”ŃĐ·Đ»ĐŸŃŃ
ĐбŃĐ”ĐșŃĐŸĐŒ ĐžŃŃĐ»Đ”ĐŽĐŸĐČĐ°ĐœĐžŃ ĐżĐŸĐŽŃĐžŃŃĐ”ĐŒĐ° ĐșĐŸŃŃĐŸĐ·ĐžĐŸĐœĐœĐŸĐłĐŸ ĐŒĐŸĐœĐžŃĐŸŃĐžĐœĐłĐ° ŃлДĐșŃŃĐŸŃ
ĐžĐŒĐžŃĐ”ŃĐșĐŸĐč Đ·Đ°ŃĐžŃŃ ĐŒĐ°ĐłĐžŃŃŃĐ°Đ»ŃĐœĐŸĐłĐŸ ĐłĐ°Đ·ĐŸĐżŃĐŸĐČĐŸĐŽĐ°. ĐŠĐ”Đ»Ń ŃĐ°Đ±ĐŸŃŃ â ĐżŃĐŸĐ°ĐœĐ°Đ»ĐžĐ·ĐžŃĐŸĐČĐ°ŃŃ ŃĐżŃĐ°ĐČĐ»Đ”ĐœĐžĐ” ŃĐžŃŃĐ”ĐŒĐŸĐč ŃлДĐșŃŃĐŸŃ
ĐžĐŒĐžŃĐ”ŃĐșĐŸĐč Đ·Đ°ŃĐžŃŃ ĐŒĐ°ĐłĐžŃŃŃĐ°Đ»ŃĐœĐŸĐłĐŸ ĐłĐ°Đ·ĐŸĐżŃĐŸĐČĐŸĐŽĐ° ĐČ ŃŃĐ»ĐŸĐČĐžŃŃ
ĐČĐ”ŃĐœĐŸĐč ĐŒĐ”ŃĐ·Đ»ĐŸŃŃ. Đ ŃДзŃĐ»ŃŃĐ°ŃĐ” Đ°ĐœĐ°Đ»ĐžĐ·Đ° ŃŃŃĐ°ĐœĐŸĐČĐ»Đ”ĐœĐŸ, ŃŃĐŸ ĐĐĐ-йХй-ĐĐŸĐœŃĐĐŸŃŃ ŃĐŽĐŸĐČлДŃĐČĐŸŃŃĐ”Ń ŃŃĐ”Đ±ĐŸĐČĐ°ĐœĐžŃĐŒ ŃĐžŃŃĐ”ĐŒŃ ŃĐżŃĐ°ĐČĐ»Đ”ĐœĐžŃ ŃĐ”Ń
ĐœĐžŃĐ”ŃĐșĐžĐŒ ŃĐŸŃŃĐŸŃĐœĐžĐ”ĐŒ Đž ŃĐ”Đ»ĐŸŃŃĐœĐŸŃŃŃŃ ĐżĐ»ĐŸŃĐ°ĐŽĐœŃŃ
ĐŸĐ±ŃĐ”ĐșŃĐŸĐČ ĐŸŃĐłĐ°ĐœĐžĐ·Đ°ŃОО.The object of study is the subsystem of corrosion monitoring of electrochemical protection of the main gas pipeline. The purpose of the work is to analyze the management of the system of electrochemical protection of the main gas pipeline in permafrost conditions. As a result of the analysis, it was established that PKM-TST-KontKorr satisfies the requirements of the system for managing the technical condition and integrity of the organizationâs area facilities
Measurement of Z0 decays to hadrons, and a precise determination of the number of neutrino species
We have made a precise measurement of the cross section for e+e--->Z0-->hadrons with the L3 detector at LEP, covering the range from 88.28 to 95.04 GeV. From a fit to the Z0 mass, total width, and the hadronic cross section to be MZ0=91.160 +/- 0.024 (experiment) +/-0.030(LEP) GeV, [Gamma]Z0=2.539+/-0.054 GeV, and [sigma]h(MZ0)=29.5+/-0.7 nb. We also used the fit to the Z0 peak cross section and the width todetermine [Gamma]invisible=0.548+/-0.029 GeV, which corresponds to 3.29+/-0.17 species of light neutrinos. The possibility of four or more neutrino flavors is thus ruled out at the 4[sigma] confidence level.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28683/3/0000500.pd
A measurement of the Z0 leptonic partial widths and the vector and axial vector coupling constants
We have measured the partial widths of the Z0 into lepton pairs, and the forward-backward charge asymmetry for the process e+e--->[mu]+[mu]- using the L3 detector at LEP. We obtain an average [Gamma]ll of 83.0+/-2.1+/-1.1 MeV.From this result and the asymmetry measurement, we extract the values of the vector and axial vector couplings of the Z0 to leptons: grmv=-0.066-0.027+0.046 and grmA= -0.495-0.007+0.007.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28666/3/0000483.pd
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