895 resultados para Guindaste lateral


Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an Extensive Air Shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 10(17) and 10(19) eV and zenith angles up to 65 degrees. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data using events simultaneously observed by the fluorescence and the surface detector of the Pierre Auger Observatory (hybrid events). We validate the Monte Carlo results showing how LTP functions from data are in good agreement with simulations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The origin of the Numidian Formation (latest Oligocene to middle Miocene), characterized by ultra-mature quartzose arenites with abundant well-rounded frosted quartz grains, remains controversial. This formation, sedimented in the external domain of the Maghrebian Flysch Basin, displays three characteristic stratigraphic members with marked longitudinal (proximal–distal) and transverse (along-chain) variations with palaeogeographical importance. The origin of the Numidian supply is related to the outward tectogenetic propagation when a forebulge evolved in the African foreland, leading to the erosion of African cratonic areas rich in quartzose arenites (Nubian Sandstone-like). The ages of the Numidian Formation checked by Betic, Maghrebian and Southern Apennine data suggest a timing for the accretionary orogenic wedge, earlier in the Betic-Rifian Arc (after middle Burdigalian), later in the Algerian-Tunisian Tell (after late Burdigalian) and afterwards in Sicily and the Southern Apennines (after Langhian). A geodynamic evolutionary model for the central-western Mediterranean is proposed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Mode of access: Internet.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

At head of title: "Repair, Evaluation, Maintenance, and Rehabilitation Research Program."

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Federal Highway Administration, Washington, D.C.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

"Aeronautical Research Laboratory. Contract No. AF 33(038)-10480, Task 70171, Project 1366."

Relevância:

20.00% 20.00%

Publicador:

Resumo:

"Aeronautical Research Laboratory. Contract no. AF 33(038)-10480, RDO no. 472-106."

Relevância:

20.00% 20.00%

Publicador:

Resumo:

"Contribution from the School of Optometry, University of California, Berkeley."

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Mode of access: Internet.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Sciatic nerve blockade (SNB) can be performed at several point along its anatomic course. Proximal SNB techniques described include the classic Labat, sacral (Mansur), infragluteal (Raj), and anterior approches Distal SNB techniques include the mid-femoral, posterior and lateral popliteal and mid-tibial approaches. The anatomic region of the lower extramity to be anesthetixzed will determine the appropriate SNB technique to use for the operative procedure.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In many neurons, trains of action potentials show frequency-dependent broadening. This broadening results from the voltage-dependent inactivation of K+ currents that contribute to action potential repolarisation. In different neuronal cell types these K+ currents have been shown to be either slowly inactivating delayed rectifier type currents or rapidly inactivating A-type voltage-gated K+ currents. Recent findings show that inactivation of a Ca2+-dependent K+ current, mediated by large conductance BK-type channels, also contributes to spike broadening. Here, using whole-cell recordings in acute slices, we examine spike broadening in lateral amygdala projection neurons. Spike broadening is frequency dependent and is reversed by brief hyperpolarisations. This broadening is reduced by blockade of voltage-gated Ca2+ channels and BK channels. In contrast, broadening is not blocked by high concentrations of 4-aminopyridine (4-AP) or alpha-dendrotoxin. We conclude that while inactivation of BK-type Ca2+-activated K+ channels contributes to spike broadening in lateral amygdala neurons, inactivation of another as yet unidentified outward current also plays a role.