12,867 research outputs found
Reduction of noise in gyro outputs
Technique is described to reduce extraneous gyro output signals by using relatively inexpensive shrouds which do not increase power comsumption. Shrouds reduce noise by minimizing mass of gas spinning with rotor, reducing Reynolds number near rotor, and inducing laminar flow
Disk tracing for B[e] supergiants in the Magellanic Clouds
B[e] supergiants are evolved massive stars with a complex circumstellar
environment. A number of important emission features probe the structure and
the kinematics of the circumstellar material. In our survey of Magellanic Cloud
B[e] supergiants we focus on the [OI] and [CaII] emission lines, which we
identified in four more objects.Comment: 2 pages; 1 figure; submitted to the proceedings of the Physics of
Evolved Stars - A conference dedicated to the memory of Olivier Chesneau,
Nice, France, June 8-12, 201
Off-shell Top Quarks with One Jet at the LHC: A comprehensive analysis at NLO QCD
We present a comprehensive study of the production of top quark pairs in
association with one hard jet in the di-lepton decay channel at the LHC. Our
predictions, accurate at NLO in QCD, focus on the LHC Run II with a
center-of-mass energy of 13 TeV. All resonant and non-resonant contributions at
the perturbative order are taken into account,
including irreducible backgrounds to production, interferences and
off-shell effects of the top quark and the gauge boson. We extensively
investigate the dependence of our results upon variation of renormalisation and
factorisation scales and parton distribution functions in the quest for an
accurate estimate of the theoretical uncertainties. Additionally, we explore a
few possibilities for a dynamical scale choice with the goal of stabilizing the
perturbative convergence of the differential cross sections far away from the
threshold. Results presented here are particularly relevant for
searches of new physics as well as for precise measurements of the top-quark
fiducial cross sections and top-quark properties at the LHC.Comment: 51 pages, 36 figures, 6 tables, version to appear in JHE
Large Area Crop Inventory Experiment (LACIE). Evaluation of multitemporal data enchancements for the identification of winter wheat fields
There are no author-identified significant results in this report
Mapping vesicle shapes into the phase diagram: A comparison of experiment and theory
Phase-contrast microscopy is used to monitor the shapes of micron-scale
fluid-phase phospholipid-bilayer vesicles in aqueous solution. At fixed
temperature, each vesicle undergoes thermal shape fluctuations. We are able
experimentally to characterize the thermal shape ensemble by digitizing the
vesicle outline in real time and storing the time-sequence of images. Analysis
of this ensemble using the area-difference-elasticity (ADE) model of vesicle
shapes allows us to associate (map) each time-sequence to a point in the
zero-temperature (shape) phase diagram. Changing the laboratory temperature
modifies the control parameters (area, volume, etc.) of each vesicle, so it
sweeps out a trajectory across the theoretical phase diagram. It is a
nontrivial test of the ADE model to check that these trajectories remain
confined to regions of the phase diagram where the corresponding shapes are
locally stable. In particular, we study the thermal trajectories of three
prolate vesicles which, upon heating, experienced a mechanical instability
leading to budding. We verify that the position of the observed instability and
the geometry of the budded shape are in reasonable accord with the theoretical
predictions. The inability of previous experiments to detect the ``hidden''
control parameters (relaxed area difference and spontaneous curvature) make
this the first direct quantitative confrontation between vesicle-shape theory
and experiment.Comment: submitted to PRE, LaTeX, 26 pages, 11 ps-fi
Rigid invariance as derived from BRS invariance: The abelian Higgs model
Consequences of a symmetry, e.g.\ relations amongst Green functions, are
renormalization scheme independently expressed in terms of a rigid Ward
identity. The corresponding local version yields information on the respective
current. In the case of spontaneous breakdown one has to define the theory via
the BRS invariance and thus to construct rigid and current Ward identity
non-trivially in accordance with it. We performed this construction to all
orders of perturbation theory in the abelian Higgs model as a prelude to the
standard model. A technical tool of interest in itself is the use of a doublet
of external scalar ``background'' fields. The Callan-Symanzik equation has an
interesting form and follows easily once the rigid invariance is established.Comment: 33 pages, Plain Te
Gyro noise study program Final report
Reducing noise induced by turbulent windage torques within gimbal of fluid rotor gyroscop
Generalized Massive Gravity and Galilean Conformal Algebra in two dimensions
Galilean conformal algebra (GCA) in two dimensions arises as contraction of
two copies of the centrally extended Virasoro algebra ( with ). The central charges of
GCA can be expressed in term of Virasoro central charges. For finite and
non-zero GCA central charges, the Virasoro central charges must behave as
asymmetric form . We propose that, the bulk
description for 2d GCA with asymmetric central charges is given by general
massive gravity (GMG) in three dimensions. It can be seen that, if the
gravitational Chern-Simons coupling behaves as of order
O() or (), the central charges
of GMG have the above dependence. So, in non-relativistic scaling
limit , we calculated GCA parameters and finite
entropy in term of gravity parameters mass and angular momentum of GMG.Comment: 9 page
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