1,973 research outputs found
Stress buildup in the Himalaya
The seismic cycle on a major fault involves long periods of elastic strain and stress accumulation, driven by aseismic ductile deformation at depth, ultimately released by sudden fault slip events. Coseismic slip distributions are generally heterogeneous with most of the energy being released in the rupture of asperities. Since, on the long term, the fault's walls generally do not accumulate any significant permanent deformation, interseismic deformation might be heterogeneous, revealing zones of focused stress buildup. The pattern of current deformation along the Himalayan arc, which is known to produce recurring devastating earthquakes, and where several seismic gaps have long been recognized, might accordingly show significant lateral variations, providing a possible explanation for the uneven microseismic activity along the Himalayan arc. By contrast, the geodetic measurements show a rather uniform pattern of interseismic strain, oriented consistently with long-term geological deformation, as indicated from stretching lineation. We show that the geodetic data and seismicity distribution are reconciled from a model in which microseismicity is interpreted as driven by stress buildup increase in the interseismic period. The uneven seismicity pattern is shown to reflect the impact of the topography on the stress field, indicating low deviatoric stresses (<35 MPa) and a low friction (<0.3) on the Main Himalayan Thrust. Arc-normal thrusting along the Himalayan front and east-west extension in southern Tibet are quantitatively reconciled by the model
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Vitis vinifera (Vitales: Vitaceae) as a Reproductive Host of Spissistilus festinus (Hemiptera: Membracidae).
Feeding by the three-cornered alfalfa hopper, Spissistilus festinus (Say) (Hemiptera: Membracidae) results in girdling of grapevine petioles and shoots. Its significance as an economic pest of grape has increased since it was shown to transmit Grapevine red blotch virus (GRBV) in a greenhouse study. However, the status of grapevines as a reproductive host for S. festinus remained undetermined. Adult S. festinus were caged onto three regions of the grapevines: apical shoot, green shoot, and dormant cane. Their ability to reproduce was determined by weekly destructive sampling for 7 wk. Successful oviposition and nymphal emergence were observed on apical and green shoots, but not on dormant canes. However, insect development beyond the second nymphal instar did not occur. Knowledge of S. festinus reproduction on grapevines will be an important consideration in designing management guidelines to minimize the spread of GRBV in vineyards
Requirements for regional short-haul air service and the definition of a flight program to determine neighborhood reactions to small transport aircraft
An evaluation of the current status and future requirements of an intraregional short haul air service is given. A brief definition of the different types of short haul air service is given. This is followed by a historical review of previous attempts to develop short haul air service in high density urban areas and an assessment of the current status. The requirements for intraregional air service, the need for economic and environmental viability and the need for a flight research program are defined. A detailed outline of a research program that would determine urban community reaction to frequent operations of small transport aircraft is also given. Both the operation of such an experiment in a specific region (San Francisco Bay area) and the necessary design modifications of an existing fixed wing aircraft which could be used in the experiment are established. An estimate is made of overall program costs
Crime and Punishment and Education
Crime impacts the lives of Kentuckians in myriad ways. It has direct costs to victims and indirect costs through property values and business activity. Citizens and policymakers alike desire to reduce and limit crime. In this brief, we investigate the link between crime rates in Kentucky’s counties and the aggregate level of education. Perhaps surprisingly, higher education, and specifically the percent of the population with a Bachelor’s degree, is associated with lower crime. We find that increasing educational attainment in Kentucky to the U.S. levels could reduce the costs of crime by over $3 million annually
An Analysis of Air Mobility Express Requirements Operating Within a Lean Logistics Wartime Environment
Lean Logistics was developed in response to budget cuts, force reductions, and a new political world order. The primary objective of Lean Logistics is to minimize the total system wide costs of the Air Force organization. Currently, the Air Force is seeking to cut costs by reducing inventories, improving repair processes, and employing faster transportation where possible. The purpose of this thesis is to determine if the Air Mobility Express (AMX) current sizing plan is capable of supporting the retrograde assets generated during the sustainment portion of a war. The Dyna-METRIC version 6.4 simulation program is employed to analyze the effect of varying such parameters as flying hours and retrograde shipment time on the weight and space required to move retrograde assets. Analysis of the results was accomplished using a Small Sample Test of Hypothesis. The results indicated that the current sizing plan is capable of handling the retrograde cargo generated by four F-16C squadrons for the six scenarios evaluated. This research also hints that while the current plan is capable of supporting four F-16C squadrons, it should be increased to support the transportation of reparables for all weapon systems involved in the war effort
Efficient engineering of multi-atom entanglement through single-photon detections
We propose an efficient scheme to engineer multi-atom entanglement by
detecting cavity decay through single-photon detectors. In the special case of
two atoms, this scheme is much more efficient than previous probabilistic
schemes, and insensitive to randomness in the atom's position. More generally,
the scheme can be used to prepare arbitrary superpositions of multi-atom Dicke
states without the requirements of high-efficiency detection and separate
addressing of different atoms.Comment: 5 pages, 2 figure
Measuring out-of-time-order correlations and multiple quantum spectra in a trapped ion quantum magnet
Controllable arrays of ions and ultra-cold atoms can simulate complex
many-body phenomena and may provide insights into unsolved problems in modern
science. To this end, experimentally feasible protocols for quantifying the
buildup of quantum correlations and coherence are needed, as performing full
state tomography does not scale favorably with the number of particles. Here we
develop and experimentally demonstrate such a protocol, which uses time
reversal of the many-body dynamics to measure out-of-time-order correlation
functions (OTOCs) in a long-range Ising spin quantum simulator with more than
100 ions in a Penning trap. By measuring a family of OTOCs as a function of a
tunable parameter we obtain fine-grained information about the state of the
system encoded in the multiple quantum coherence spectrum, extract the quantum
state purity, and demonstrate the buildup of up to 8-body correlations. Future
applications of this protocol could enable studies of many-body localization,
quantum phase transitions, and tests of the holographic duality between quantum
and gravitational systems.Comment: main text: 7 pages, 4 figures; supplement: 9 pages, 4 figure
Periodic spatial variation of the electron-phonon interaction in epitaxial graphene on Ru(0001
We have performed low temperature scanning tunnelling spectroscopy (STS)
measurements on graphene epitaxially grown on Ru(0001). An inelastic feature,
related to the excitation of a vibrational breathing mode of the graphene
lattice, was found at 360 meV. The change in the differential electrical
conductance produced by this inelastic feature, which is associated with the
electron-phonon interaction strength, varies spatially from one position to
other of the graphene supercell. This inhomogeneity in the electronic
properties of graphene on Ru(0001) results from local variations of the
carbon-ruthenium interaction due to the lattice mismatch between the graphene
and the Ru(0001) lattices.Comment: 6 Pages, 3 figure
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