368 research outputs found
Introduction to the Special Issue on the 2011 Tohoku Earthquake and Tsunami
The 11 March 2011 Tohoku earthquake (05:46:24 UTC) involved a massive rupture of the plate‐boundary fault along which the Pacific plate thrusts under northeastern Honshu, Japan. It was the fourth‐largest recorded earthquake, with seismic‐moment estimates of 3–5×10^(22) N•m (M_w 9.0). The event produced widespread strong ground shaking in northern Honshu; in some locations ground accelerations exceeded 2g. Rupture extended ∼200 km along dip, spanning the entire width of the seismogenic zone from the Japan trench to below the Honshu coastline, and the aftershock‐zone length extended ∼500 km along strike of the subduction zone. The average fault slip over the entire rupture area was ∼10 m, but some estimates indicate ∼25 m of slip located around the hypocentral region and extraordinary slip of up to 60–80 m in the shallow megathrust extending to the trench. The faulting‐generated seafloor deformation produced a devastating tsunami that resulted in 5–10‐km inundation of the coastal plains, runup of up to 40 m along the Sanriku coastline, and catastrophic failure of the backup power systems at the Fukushima Daiichi nuclear power station, which precipitated a reactor meltdown and radiation release. About 18,131 lives appear to have been lost, 2829 people are still missing, and 6194 people were injured (as reported 28 September 2012 by the Fire and Disaster Management Agency of Japan) and over a half million were displaced, mainly due to the tsunami impact on coastal towns, where tsunami heights significantly exceeded harbor tsunami walls and coastal berms
Smart Handover with Predicted User Behavior using Convolutional Neural Networks for WiGig Systems
WiGig networks and 60 GHz frequency communications have a lot of potential
for commercial and personal use. They can offer extremely high transmission
rates but at the cost of low range and penetration. Due to these issues, WiGig
systems are unstable and need to rely on frequent handovers to maintain
high-quality connections. However, this solution is problematic as it forces
users into bad connections and downtime before they are switched to a better
access point. In this work, we use Machine Learning to identify patterns in
user behaviors and predict user actions. This prediction is used to do
proactive handovers, switching users to access points with better future
transmission rates and a more stable environment based on the future state of
the user. Results show that not only the proposal is effective at predicting
channel data, but the use of such predictions improves system performance and
avoids unnecessary handovers.Comment: Submitted to IEEE Networ
Preparação de l-carvona a partir de d-limoneno.
A l-carvona foi obtida a partir de d-limoneno, utilizando-se reação em três etapas: transformação do d-limoneno e nitrosocloreto de d-limoneno; conversão do nitrosocloreto de d-limoneno em l-carvoxima; hidrólise da l-carvoxima em l-carvona e purifricação de l-carvona por destilação a vácuo. A contribuição mais significativa do presente processo em relação aos existentes é ter sido feita a deidrocloração do nitrosocloreto de d-limoneno sem o uso de bases, procedendo-se a um aquecimento controlado (52 a 56oC) do comosto em solvente adequado, preferivelmente etanol. O rendimento líquido da tansformação do d-limoneno foi de 38 a 49% e o produto final satisfaz as especificações para o uso comercial, inclusive quanto às características de odor e sabor.bitstream/item/65439/1/CTAA-DOCUMENTOS-15-PREPARACAO-DE-L-CARVONA-A-PARTIR-DE-D-LIMONENO-FL-06778.pd
Linalol, principal componente químico dos óleos essenciais da folha da sacaca (Croton cajucara Benth) e da madeira do pau-rosa (Aniba duckei Kostermans).
Verificação, de forma exploratória, dos efeitos de nutrientes químicos e orgânicos no rendimento em óleo e no teor de linalol de sacaca cultivada na área experimental da Embrapa Amazônia Ocidental (Manaus-AM).bitstream/CPAA-2009-09/2734/1/Com_Tec_15.pd
Teores de princípios pungentes de algumas pimentas do gênero capsicum cultivadas no Brasil.
bitstream/item/65463/1/CTAA-DOCUMENTOS-19-TEORES-DE-PRINCIPIOS-PUNGENTES-DE-ALGUMAS-PIMENTAS-DO-GENEROS-CAPSICUM-CULTIVA.pd
Óleos essenciais de frutos cítricos cultivados no Brasil.
Foram estudados, quanto à composição química e constantes físico-químicas, dos óleos essenciais de 5 grupos de frutos cítricos cultivados no Brasil (laranja, limão, tangerina, bergamota e "grapefruit"), num total de 12 diferentes óleos de 32 amostras. Objetivou-se avaliar a qualidade desses óleos do ponto de vista químico e contribuir com subsídios para a padronização dos mesmos. Concluiu-se que, quanto à composição química e quanto aos valores das constantes de poder rotatório, índice de refração densidade, os óleos analisados apresentam características comparáveis aos valores citados pela literatura para óleos essenciais cítrico de diferentes origens geográficas.bitstream/item/65375/1/CTAA-DOCUMENTOS-007-OLEOS-ESSENCIAIS-DE-FRUTAS-CITRICAS-CULTIVADAS-NO-BRASIL-FL-06784A.pd
A field expansions method for scattering by periodic multilayered media
The interaction of acoustic and electromagnetic waves with periodic structures plays an important role in a wide range of problems of scientific and technological interest. This contribution focuses upon the robust and high-order numerical simulation of a model for the interaction of pressure waves generated within the earth incident upon layers of sediment near the surface. Herein described is a boundary perturbation method for the numerical simulation of scattering returns from irregularly shaped periodic layered media. The method requires only the discretization of the layer interfaces (so that the number of unknowns is an order of magnitude smaller than finite difference and finite element simulations), while it avoids not only the need for specialized quadrature rules but also the dense linear systems characteristic of boundary integral/element methods. The approach is a generalization to multiple layers of Bruno and Reitich’s “Method of Field Expansions” for dielectric structures with two layers. By simply considering the entire structure simultaneously, rather than solving in individual layers separately, the full field can be recovered in time proportional to the number of interfaces. As with the original field expansions method, this approach is extremely efficient and spectrally accurate
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