1,026 research outputs found
Advanced superconducting magnets investigation
Mathematical models for steady state behavior of composite superconductors and experimental verification using magnet coi
The EOS Prototype Validation Exercise (PROVE) at Jornada: Overview and Lessons Learned
The Earth Observing System (EOS) instrument teams must validate the operational products they produce from the Terra spacecraft data. As a pilot for future validation activities, four EOS teams (MODIS, MISR, ASTER, and Landsat-7) and community experts conducted an 11-day field campaign in May 1997 near Las Cruces, NM. The goals of the Prototype Validation Exercise (PROVE) included (1) gaining experience in the collection and use of field data for EOS product validation; (2) developing coordination, measurement, and data-archiving protocols; and (3) compiling a synoptic land and atmospheric data set for testing algorithms. PROVE was held at the USDA-Agricultural Research Service’s (ARS) Jornada Experimental Range, an expansive desert plateau hosting a complex mosaic of grasses and shrubs. Most macroscopic variables affecting the radiation environment were measured with ground, air-borne (including AVIRIS and laser altimeter), and space-borne sensors (including AVHRR, Landsat TM, SPOT, POLDER, and GOES). The Oak Ridge Distributed Active Archive Center (DAAC) then used campaign data sets to prototype Mercury, its Internet-based data harvesting and distribution system. This article provides general information about PROVE and assesses the progress made toward the campaign goals. Primary successes included the rapid campaign formulation and execution, measurement protocol development, and the significant collection, reduction, and sharing of data among participants. However, the PROVE data were used primarily for arid-land research and model validation rather than for validating satellite products, and the data were slow to reach the DAAC and hence public domain. The lessons learned included: (1) validation campaigns can be rapidly organized and implemented if there are focused objectives and on-site facilities and expertise; (2) data needs, organization, storage, and access issues must be addressed at the onset of campaign planning; and (3) the end-to-end data collection, release, and publication environment may need to be readdressed by program managers , funding agencies, and journal editors if rapid and comprehensive validation of operational satellite products is to occur
SeaWiFS technical report series. Volume 27: Case studies for SeaWiFS calibration and validation, part 3
This document provides brief reports, or case studies, on a number of investigations sponsored by the Calibration and Validation Team (CVT) within the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Project. Chapter I describes a comparison of the irradiance immersion coefficients determined for several different marine environmental radiometers (MERs). Chapter 2 presents an analysis of how light absorption by atmospheric oxygen will influence the radiance measurements in band 7 of the SeaWiFS instrument. Chapter 3 gives the results of the second ground-based solar calibration of the instrument, which was undertaken after the sensor was modified to reduce the effects of internal stray light. (The first ground-based solar calibration of SeaWiFS is described in Volume 19 in the SeaWiFS Technical Report Series.) Chapter 4 evaluates the effects of ship shadow on subsurface irradiance and radiance measurements deployed from the deck of the R/V Weatherbird 11 in the Atlantic Ocean near Bermuda. Chapter 5 illustrates the various ways in which a single data day of SeaWiFS observations can be defined, and why the spatial definition is superior to the temporal definition for operational usage
Studies of multiplicity in relativistic heavy-ion collisions
In this talk I'll review the present status of charged particle multiplicity
measurements from heavy-ion collisions. The characteristic features of
multiplicity distributions obtained in Au+Au collisions will be discussed in
terms of collision centrality and energy and compared to those of p+p
collisions. Multiplicity measurements of d+Au collisions at 200 GeV
nucleon-nucleon center-of-mass energy will also be discussed. The results will
be compared to various theoretical models and simple scaling properties of the
data will be identified.Comment: "Focus on Multiplicity" Internationsl Workshop on Particle
Multiplicity in Relativistic Heavy Ion Collisions, Bari, Italy, June 17-19,
2003, 16 pages, 15 figure
RNA fusions involving CD28 are rare in peripheral T-cell lymphomas and concentrate mainly in those derived from follicular helper T cells.
Research lette
Multiplicity Studies and Effective Energy in ALICE at the LHC
In this work we explore the possibility to perform ``effective energy''
studies in very high energy collisions at the CERN Large Hadron Collider (LHC).
In particular, we focus on the possibility to measure in collisions the
average charged multiplicity as a function of the effective energy with the
ALICE experiment, using its capability to measure the energy of the leading
baryons with the Zero Degree Calorimeters. Analyses of this kind have been done
at lower centre--of--mass energies and have shown that, once the appropriate
kinematic variables are chosen, particle production is characterized by
universal properties: no matter the nature of the interacting particles, the
final states have identical features. Assuming that this universality picture
can be extended to {\it ion--ion} collisions, as suggested by recent results
from RHIC experiments, a novel approach based on the scaling hypothesis for
limiting fragmentation has been used to derive the expected charged event
multiplicity in interactions at LHC. This leads to scenarios where the
multiplicity is significantly lower compared to most of the predictions from
the models currently used to describe high energy collisions. A mean
charged multiplicity of about 1000-2000 per rapidity unit (at ) is
expected for the most central collisions at .Comment: 12 pages, 19 figures. In memory of A. Smirnitski
Equations of Motion of Spinning Relativistic Particle in Electromagnetic and Gravitational Fields
We consider the motion of a spinning relativistic particle in external
electromagnetic and gravitational fields, to first order in the external field,
but to an arbitrary order in spin. The noncovariant spin formalism is crucial
for the correct description of the influence of the spin on the particle
trajectory. We show that the true coordinate of a relativistic spinning
particle is its naive, common coordinate \r. Concrete calculations are
performed up to second order in spin included. A simple derivation is presented
for the gravitational spin-orbit and spin-spin interactions of a relativistic
particle. We discuss the gravimagnetic moment (GM), a specific spin effect in
general relativity. It is shown that for the Kerr black hole the gravimagnetic
ratio, i.e., the coefficient at the GM, equals unity (just as for the charged
Kerr hole the gyromagnetic ratio equals two). The equations of motion obtained
for relativistic spinning particle in external gravitational field differ
essentially from the Papapetrou equations.Comment: 32 pages, latex, Plenary talk at the Fairbank Meeting on the
Lense--Thirring Effect, Rome-Pescara, 29/6-4/7 199
Study of CP violation in Dalitz-plot analyses of B0 --> K+K-KS, B+ --> K+K-K+, and B+ --> KSKSK+
We perform amplitude analyses of the decays , , and , and measure CP-violating
parameters and partial branching fractions. The results are based on a data
sample of approximately decays, collected with the
BABAR detector at the PEP-II asymmetric-energy factory at the SLAC National
Accelerator Laboratory. For , we find a direct CP asymmetry
in of , which differs
from zero by . For , we measure the
CP-violating phase .
For , we measure an overall direct CP asymmetry of
. We also perform an angular-moment analysis of
the three channels, and determine that the state can be described
well by the sum of the resonances , , and
.Comment: 35 pages, 68 postscript figures. v3 - minor modifications to agree
with published versio
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