19,754 research outputs found
SO(10) and Large nu_mu - nu_tau Mixing
A general approach to understanding the large mixing seen in atmospheric
neutrinos is explained, as well as a highly predictive SO(10) model which
implements this approach. It is also seen how bimaximal mixing naturally arises
in this scheme. (Talk presented at NNN99, SUNY Stony Brook, Sept. 22-26, 1999)Comment: 10 pages, LaTe
A Common Origin for Ridge-and-Trough Terrain on Icy Satellites by Sluggish Lid Convection
Ridge-and-trough terrain is a common landform on outer Solar System icy
satellites. Examples include Ganymede's grooved terrain, Europa's gray bands,
Miranda's coronae, and several terrains on Enceladus. The conditions associated
with the formation of each of these terrains are similar: heat flows of order
tens to a hundred milliwatts per meter squared, and deformation rates of order
to s. Our prior work shows that the conditions
associated with the formation of these terrains on Ganymede and the south pole
of Enceladus are consistent with vigorous solid-state ice convection in a shell
with a weak surface. We show that sluggish lid convection, an intermediate
regime between the isoviscous and stagnant lid regimes, can create the heat
flow and deformation rates appropriate for ridge and trough formation on a
number of satellites, regardless of the ice shell thickness. For convection to
deform their surfaces, the ice shells must have yield stresses similar in
magnitude to the daily tidal stresses. Tidal and convective stresses deform the
surface, and the spatial pattern of tidal cracking controls the locations of
ridge-and-trough terrain.Comment: 45 pages, 7 figures; accepted for publication in Physics of the Earth
and Planetary Interior
The stransverse mass, MT2, in special cases
This document describes some special cases in which the stransverse mass,
MT2, may be calculated by non-iterative algorithms. The most notable special
case is that in which the visible particles and the hypothesised invisible
particles are massless -- a situation relevant to its current usage in the
Large Hadron Collider as a discovery variable, and a situation for which no
analytic answer was previously known. We also derive an expression for MT2 in
another set of new (though arguably less interesting) special cases in which
the missing transverse momentum must point parallel or anti parallel to the
visible momentum sum. In addition, we find new derivations for already known
MT2 solutions in a manner that maintains manifest contralinear boost invariance
throughout, providing new insights into old results. Along the way, we stumble
across some unexpected results and make conjectures relating to geometric forms
of M_eff and H_T and their relationship to MT2.Comment: 11 pages, no figures. v2 corrects minor typos. v3 corrects an
incorrect statement in footnote 8 and inserts a missing term in eq (3.9). v4
and v5 correct minor typos spotted by reader
Resilience of Hierarchical Critical Infrastructure Networks
Concern over the resilience of critical infrastructure networks has increased dramatically over the last decade due to a
number of well documented failures and the significant disruption associated with these. This has led to a large body of
research that has adopted graph-theoretic based analysis in order to try and improve our understanding of infrastructure
network resilience. Many studies have asserted that infrastructure networks possess a scale-free topology which is
robust to random failures but sensitive to targeted attacks at highly connected hubs. However, many studies have
ignored that many networks in addition to their topological connectivity may be organised either logically or spatially
in a hierarchical system which may significantly change their response to perturbations. In this paper we explore if
hierarchical network models exhibit significantly different higher-order topological characteristics compared to other
network structures and how this impacts on their resilience to a number of different failure types. This is achieved by
investigating a suite of synthetic networks as well as a suite of ‘real world’ spatial infrastructure networks
Interior Structures and Tidal Heating in the TRAPPIST-1 Planets
With seven planets, the TRAPPIST-1 system has the largest number of
exoplanets discovered in a single system so far. The system is of
astrobiological interest, because three of its planets orbit in the habitable
zone of the ultracool M dwarf. Assuming the planets are composed of
non-compressible iron, rock, and HO, we determine possible interior
structures for each planet. To determine how much tidal heat may be dissipated
within each planet, we construct a tidal heat generation model using a single
uniform viscosity and rigidity for each planet based on the planet's
composition. With the exception of TRAPPIST-1c, all seven of the planets have
densities low enough to indicate the presence of significant HO in some
form. Planets b and c experience enough heating from planetary tides to
maintain magma oceans in their rock mantles; planet c may have eruptions of
silicate magma on its surface, which may be detectable with next-generation
instrumentation. Tidal heat fluxes on planets d, e, and f are lower, but are
still twenty times higher than Earth's mean heat flow. Planets d and e are the
most likely to be habitable. Planet d avoids the runaway greenhouse state if
its albedo is 0.3. Determining the planet's masses within
to 0.5 Earth masses would confirm or rule out the presence of HO and/or
iron in each planet, and permit detailed models of heat production and
transport in each planet. Understanding the geodynamics of ice-rich planets f,
g, and h requires more sophisticated modeling that can self-consistently
balance heat production and transport in both rock and ice layers.Comment: 34 pages, 3 tables, 4 figures. Accepted for publication in Astronomy
& Astrophysics -- final version including corrections made in proof stag
A comment on "Amplification of endpoint structure for new particle mass measurement at the LHC"
We present a comment on the kinematic variable recently proposed in
"Amplification of endpoint structure for new particle mass measurement at the
LHC". The variable is designed to be applied to models such as R-parity
conserving Supersymmetry (SUSY) when there is pair production of new heavy
particles each of which decays to a single massless visible and a massive
invisible component. It was proposed in "Amplification of endpoint structure
for new particle mass measurement at the LHC" that a measurement of the peak of
the distribution could be used to precisely constrain the masses of
the SUSY particles. We show that when Standard Model backgrounds are included
in simulations, the sensitivity of the variable to the SUSY particle
masses is more seriously impacted for than for other previously
proposed variables.Comment: 5 page
A manual for inexpensive methods of analyzing and utilizing remote sensor data
Instructions are provided for inexpensive methods of using remote sensor data to assist in the completion of the need to observe the earth's surface. When possible, relative costs were included. Equipment need for analysis of remote sensor data is described, and methods of use of these equipment items are included, as well as advantages and disadvantages of the use of individual items. Interpretation and analysis of stereo photos and the interpretation of typical patterns such as tone and texture, landcover, drainage, and erosional form are described. Similar treatment is given to monoscopic image interpretation, including LANDSAT MSS data. Enhancement techniques are detailed with respect to their application and simple techniques of creating an enhanced data item. Techniques described include additive and subtractive (Diazo processes) color techniques and enlargement of photos or images. Applications of these processes, including mappings of land resources, engineering soils, geology, water resources, environmental conditions, and crops and/or vegetation, are outlined
Application transfer activity in Missouri
Experimental demonstrations and workshop instructional courses were conducted to transfer the technology of satellite remote sensing to a wide audience of resource managers. This audience included planning commissions, state agencies, federal agencies, and special councils of the Governor. Some of the experiments and workshops are outlined
Knee kinematics of total knee replacement patients: pre and post operative analysis using computer generated images
This project aims to show a comparison of knee kinematics in pre- and post-operative knee replacement surgery, using computer animation to represent a patient specific model of the knee joint interactions under every day conditions
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