Mechanical Properties and Fracture Dynamics of Silicene Membranes

As graphene became one of the most important materials today, there is a renewed interest on others similar structures. One example is silicene, the silicon analogue of graphene. It share some the remarkable graphene properties, such as the Dirac cone, but presents some distinct ones, such as a pronounced structural buckling. We have investigated, through density functional based tight-binding (DFTB), as well as reactive molecular dynamics (using ReaxFF), the mechanical properties of suspended single-layer silicene. We calculated the elastic constants, analyzed the fracture patterns and edge reconstructions. We also addressed the stress distributions, unbuckling mechanisms and the fracture dependence on the temperature. We analysed the differences due to distinct edge morphologies, namely zigzag and armchair

General rules for bosonic bunching in multimode interferometers

We perform a comprehensive set of experiments that characterize bosonic bunching of up to 3 photons in interferometers of up to 16 modes. Our experiments verify two rules that govern bosonic bunching. The first rule, obtained recently in [1,2], predicts the average behavior of the bunching probability and is known as the bosonic birthday paradox. The second rule is new, and establishes a n!-factor quantum enhancement for the probability that all n bosons bunch in a single output mode, with respect to the case of distinguishable bosons. Besides its fundamental importance in phenomena such as Bose-Einstein condensation, bosonic bunching can be exploited in applications such as linear optical quantum computing and quantum-enhanced metrology.Comment: 6 pages, 4 figures, and supplementary material (4 pages, 1 figure

Dynamical Aspects Of The Unzipping Of Multiwalled Boron Nitride Nanotubes.

Boron nitride nanoribbons (BNNRs) exhibit very interesting magnetic properties, which could be very useful in the development of spintronic based devices. One possible route to obtain BNNRs is through the unzipping of boron nitride nanotubes (BNNTs), which have been already experimentally realized. In this work, different aspects of the unzipping process of BNNTs were investigated through fully atomistic molecular dynamics simulations using a classical reactive force field (ReaxFF). We investigated multiwalled BNNTs of different diameters and chiralities. Our results show that chirality plays a very important role in the unzipping process, as well as the interlayer coupling. These combined aspects significantly change the fracturing patterns and several other features of the unzipping processes in comparison to the ones observed for carbon nanotubes. Also, similar to carbon nanotubes, defective BNNTs can create regions of very high curvature which can act as a path to the unzipping process.1519147-5

Fava - nova alternativa agricola para o Estado do Amazonas.

Dando continuidade ao trabalho iniciado em 1981, com fava (Phaseolus lunatus) instalou-se em 1982 no Campo Experimental da UEPAE de Manaus localizado no Km 30 da rodovia AM-010 (Manaus/Itacoatiara), um ensaio onde foram estudadas as seis cultivares mais promissoras para a Região dentre as dezesseis introduzidas e avaliadas em 1981. O Experimento foi instalado em área de capoeira, com três anos de pousio, cuja unidade pedogenética pertence ao grupo dos Latossolos Amarelos, textura argilosa. O referido experimento foi preparado mecanicamente.bitstream/item/83148/1/Pesquisa-42-1983.pd

Multi-Hamiltonian structure of Plebanski's second heavenly equation

We show that Plebanski's second heavenly equation, when written as a first-order nonlinear evolutionary system, admits multi-Hamiltonian structure. Therefore by Magri's theorem it is a completely integrable system. Thus it is an example of a completely integrable system in four dimensions

Avaliação de doenças em germoplasma de arroz em várzea e em terra firme no Amazonas.

Foram estudadas as principais doenças de arroz que ocorrem em Manaus. Foi constatada a incidência de Helminthosporium oryzae, Pyriculatia oryzae, Rhinchosporium oryzae, Cercospora oryzae e Rhizoctonia solani atacando arroz em ambos os ecossistemas. Na terra firme, a principal doença observada foi a mancha-do-grão e a mancha-parda, causadas por H. oryzae. Na várzea, a queima da bainha e do colmo teve incidência acima de 25%, porém tardia, não afetando o peso de panículas nem o índice de mancha ou chochamento do grão

Planting dates in relation to weather pattern at Manaus, Brazil.

bitstream/item/210628/1/Planting-Dates-in-Relation....pd