11,812 research outputs found
Utilizing Online Software for Surveys
In institutions where assessment is part of our everyday vocabulary, we are always looking for ways to collect the data that we need in a more efficient manner. Online surveys may be one answer. There are some major advantages in using online surveys but there are also some critical disadvantages especially concerning representative population samples. In order to make an informed decision, we need to determine if and how these advantages and disadvantages affect our situation. We also need to understand what features are offered in these programs so that we can select a program that meets our own needs and budgets
Measurement of heavy-flavor production in Pb-Pb collisions at the LHC with ALICE
A Large Ion Collider Experiment (ALICE) at the Large Hadron Collider (LHC)
has been built in order to study the Quark-Gluon Plasma (QGP) created in
high-energy nuclear collisions. As heavy-flavor quarks are produced at the
early stage of the collision, they serve as sensitive probes for the QGP. The
ALICE detector with its capabilities such as particle identification, secondary
vertexing and tracking in a high multiplicity environment can address, among
other measurements, the heavy-flavor sector in heavy-ion collisions. We present
latest results on the measurement of the nuclear modification factor of open
heavy-flavors as well as on the measurement of open heavy-flavor azimuthal
anisotropy v2 in Pb-Pb collisions at sqrt(s) = 2.76 TeV. Open charmed hadrons
are reconstructed in the hadronic decay channels D0->Kpi, D+->Kpipi, and
D*+->D0pi applying a secondary decay-vertex topology. Complementary
measurements are performed by detecting electrons (muons) from semi-leptonic
decays of open heavy-flavor hadrons in the central (forward) rapidity region.Comment: 10 pages, 6 figures. Talk given by Robert Grajcarek at the 11th
International Conference on Nucleus-Nucleus Collisions (NN2012), San Antonio,
Texas, USA, May 27-June 1, 2012. To appear in the NN2012 Proceedings in
Journal of Physics: Conference Series (JPCS
The Laser of the ALICE Time Projection Chamber
The large TPC () of the ALICE detector at the CERN LHC was
commissioned in summer 2006. The first tracks were observed both from the
cosmic ray muons and from the laser rays injected into the TPC. In this article
the basic principles of operating the lasers are presented,
showing the installation and adjustment of the optical system and describing
the control system. To generate the laser tracks, a wide laser beam is split
into several hundred narrow beams by fixed micro-mirrors at stable and known
positions throughout the TPC. In the drift volume, these narrow beams generate
straight tracks at many angles. Here we describe the generation of the first
tracks and compare them with simulations.Comment: QM06 poster proceedings, 6 pages, 4 figure
Formal rigidity of the Witt and Virasoro Algebra
The formal rigidity of the Witt and Virasoro algebras was first established
by the author in [4]. The proof was based on some earlier results of the author
and Goncharowa, and was not presented there. In this paper we give an
elementary proof of these facts.Comment: 5 page
Level-1 jet trigger hardware for the ALICE electromagnetic calorimeter at LHC
The ALICE experiment at the LHC is equipped with an electromagnetic
calorimeter (EMCal) designed to enhance its capabilities for jet measurement.
In addition, the EMCal enables triggering on high energy jets. Based on the
previous development made for the Photon Spectrometer (PHOS) level-0 trigger, a
specific electronic upgrade was designed in order to allow fast triggering on
high energy jets (level-1). This development was made possible by using the
latest generation of FPGAs which can deal with the instantaneous incoming data
rate of 26 Gbit/s and process it in less than 4 {\mu}s.Comment: proceeding of TWEPP-10 at Aachen. 6 pages, 4 figure
The construction of a unit and workbook of exercises for the slow learner to develop comprehension and increase study skills for use in the teaching of an American history unit on the westward movement in the United States on a sixth grade level.
Thesis (Ed.M.)--Boston University
N.B.:pages missing: 170, 171, 173 from original cop
Falling liquid films with blowing and suction
Flow of a thin viscous film down a flat inclined plane becomes unstable to
long wave interfacial fluctuations when the Reynolds number based on the mean
film thickness becomes larger than a critical value (this value decreases as
the angle of inclination with the horizontal increases, and in particular
becomes zero when the plate is vertical). Control of these interfacial
instabilities is relevant to a wide range of industrial applications including
coating processes and heat or mass transfer systems. This study considers the
effect of blowing and suction through the substrate in order to construct from
first principles physically realistic models that can be used for detailed
passive and active control studies of direct relevance to possible experiments.
Two different long-wave, thin-film equations are derived to describe this
system; these include the imposed blowing/suction as well as inertia, surface
tension, gravity and viscosity. The case of spatially periodic blowing and
suction is considered in detail and the bifurcation structure of forced steady
states is explored numerically to predict that steady states cease to exist for
sufficiently large suction speeds since the film locally thins to zero
thickness giving way to dry patches on the substrate. The linear stability of
the resulting nonuniform steady states is investigated for perturbations of
arbitrary wavelengths, and any instabilities are followed into the fully
nonlinear regime using time-dependent computations. The case of small amplitude
blowing/suction is studied analytically both for steady states and their
stability. Finally, the transition between travelling waves and non-uniform
steady states is explored as the suction amplitude increases
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