25,609 research outputs found
Warping the Universal Extra Dimensions
We develop the necessary ingredients for the construction of realistic models
with warped universal extra dimensions. Our investigations are based on the
seven dimensional (7D) spacetime AdS_5 x T^2 and we derive the Kaluza-Klein
(KK) spectra for gravitons, bulk vectors and the TeV brane localized Higgs
boson. We show that, starting with a massive 7D fermion, one may obtain a
single chiral massless mode whose profile is readily localized towards the
Planck or TeV brane. This allows one to place the standard model fermions in
the bulk and construct models of flavor as in Randall-Sundrum models. Our
solution also admits the familiar KK parity of UED models so that the lightest
odd KK state is stable and may be a dark matter (DM) candidate. As an
additional feature the AdS_5 warping ensures that the excited modes on the
torus, including the DM candidate, appear at TeV energies (as is usually
assumed in UED models) even though the Planck scale sets the dimensions for the
torus.Comment: 22 pages. V2 References added and minor changes mad
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2019-nCoV: The Identify-Isolate-Inform (3I) Tool Applied to a Novel Emerging Coronavirus
2019 Novel Coronavirus (2019-nCoV) is an emerging infectious disease closely related to MERS-CoV and SARS-CoV that was first reported in Wuhan City, Hubei Province, China in December 2019. As of January 2020, cases of 2019-nCoV are continuing to be reported in other Eastern Asian countries as well as in the United States, Europe, Australia, and numerous other countries. An unusually high volume of domestic and international travel corresponding to the beginning of the 2020 Chinese New Year complicated initial identification and containment of infected persons. Due to the rapidly rising number of cases and reported deaths, all countries should be considered at risk of imported 2019-nCoV. Therefore, it is essential for prehospital, clinic, and emergency department personnel to be able to rapidly assess 2019-nCoV risk and take immediate actions if indicated. The Identify-Isolate-Inform (3I) tool, originally conceived for the initial detection and management of Ebola virus and later adjusted for other infectious agents, can be adapted for any emerging infectious disease. This paper reports a modification of the 3I tool for use in the initial detection and management of patients under investigation for 2019-nCoV. After initial assessment for symptoms and epidemiological risk factors, including travel to affected areas and exposure to confirmed 2019-nCoV patients within 14 days, patients are classified in a risk-stratified system. Upon confirmation of a suspected 2019-nCoV case, affected persons must immediately be placed in airborne infection isolation and the appropriate public health agencies notified. This modified 3I tool will assist emergency and primary care clinicians, as well as out-of-hospital providers, in effectively managing persons with suspected or confirmed 2019-nCoV
Residual stress in plasma sprayed ceramic turbine tip and gas path seal specimens
The residual stresses in a ceramic sheet material used for turbine blade tip gas path seals, were estimated. These stresses result from the plasma spraying process which leaves the surface of the sheet in tension. To determine the properties of plasma sprayed ZrO2-Y2O3 sheet material, its load deflection characteristics were measured. Estimates of the mechanical properties for sheet materials were found to differ from those reported for plasma sprayed bulk materials
Broken Symmetry as a Stabilizing Remnant
The Goldberger-Wise mechanism enables one to stabilize the length of the
warped extra dimension employed in Randall-Sundrum models. In this work we
generalize this mechanism to models with multiple warped throats sharing a
common ultraviolet brane. For independent throats this generalization is
straight forward. If the throats possess a discrete interchange symmetry like
Z_n the stabilizing dynamics may respect the symmetry, resulting in equal
throat lengths, or they may break it. In the latter case the ground state of an
initially symmetric configuration is a stabilized asymmetric configuration in
which the throat lengths differ. We focus on two- (three-) throat setups with a
Z_2 (Z_3) interchange symmetry and present stabilization dynamics suitable for
either breaking or maintaining the symmetry. Though admitting more general
application, our results are relevant for existing models in the literature,
including the two throat model with Kaluza-Klein parity and the three throat
model of flavor based on a broken Z_3 symmetry.Comment: 23 pages; v2 minor cosmetic chang
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