Electron trapping and acceleration by the plasma wakefield of a self-modulating proton beam

It is shown that co-linear injection of electrons or positrons into the wakefield of the self-modulating particle beam is possible and ensures high energy gain. The witness beam must co-propagate with the tail part of the driver, since the plasma wave phase velocity there can exceed the light velocity, which is necessary for efficient acceleration. If the witness beam is many wakefield periods long, then the trapped charge is limited by beam loading effects. The initial trapping is better for positrons, but at the acceleration stage a considerable fraction of positrons is lost from the wave. For efficient trapping of electrons, the plasma boundary must be sharp, with the density transition region shorter than several centimeters. Positrons are not susceptible to the initial plasma density gradient.Comment: 9 pages, 9 figures, 1 table, 44 reference

Tensor Coordinates in Noncommutative Mechanics

A consistent classical mechanics formulation is presented in such a way that, under quantization, it gives a noncommutative quantum theory with interesting new features. The Dirac formalism for constrained Hamiltonian systems is strongly used, and the object of noncommutativity ${\mathbf \theta}^{ij}$ plays a fundamental rule as an independent quantity. The presented classical theory, as its quantum counterpart, is naturally invariant under the rotation group $SO(D)$.Comment: 12 pages, Late

Evolução do desmatamento e do passivo ambiental em projeto de assentamento de reforma agrária no Sudeste Paraense.

Atualmente os Projetos de Assentamentos de Reforma agrária do Sudeste Paraense estão no foco das discussões sobre a perda de cobertura florestal na Amazônia, pois figuram entre as áreas que mais contribuem para o processo de desmatamento. Neste sentido, este trabalho objetivou avaliar a evolução do desmatamento e do passivo ambiental no Projeto de Assentamento São Francisco, município de Eldorado do Carajás, em um universo temporal que vai de 1990 a 2020, identificando os principais processos que levam a perda da cobertura florestal no local de estudo. Para tanto, o trabalho foi baseado e sustentado por métodos de análise da paisagem, nomeadamente as geotecnologias, adotando-se os mesmos conceitos trabalhados pelo PRODES que mensura polígonos de desmatamento por corte raso. No geral, observou-se um significativo aumento do desmatamento no local de estudo, que perdeu aproximadamente 5.000 hectares de vegetação. Em termos gerais, essa taxa representa mais de 60% de floresta perdida e convertida em outros usos. Atualmente, a nível de reserva legal, o passivo ambiental chega a mais de 20% do total da área e em relação as APP’s houve uma redução também de mais 20% na vegetação ciliar, o que implica na perda de importantes serviços ambientais prestados por esses locais. Percebe-se assim, que sem o uso de tecnologia agropecuária adequada e assistência técnica aos pequenos produtores não há uma sustentabilidade dos meios de produção e dos recursos naturais a longo prazo, sendo necessárias alternativas de produção que aliem o aproveitamento das áreas já abertas, gerando emprego e rend

Estabelecimento e indução de brotos via meristema da cultivar Kuthiravally de pimenta-do-reino.

São de suma importância os estudos realizados in vitro para multiplicar e propagar genótipos de pimenta-do-reino resistentes a doenças e a utilização de cultivares possibilitou o aumento da produtividade aos pipericultores. Assim, o objetivo deste trabalho foi realizar o estabelecimento de plântulas da cultivar Kuthiravally via meristema, a fim de disponibilizar mudas vigorosas e com alta produtividade ao produtor. Para a obtenção dos brotos foi preparado o meio nutritivo MS (Murashige & Skoop) para a diferenciação in vitro, com sacarose a 3% e 0,5 mg.L-1 de BAP (Benzilaminopurina). A contagem dos números de gemas/brotos foi estipulada quando os explantes foram inoculados em meio de enraizamento suplementado com 0,05 de ANA (Ácido naftalenacético). Em média foram obtidos cerca de 14,77 gemas por frasco, permitindo uma multiplicação aceitável para produção de mudas. O enraizamento foi realizado, porém ainda está sob análise

Evaluation of a Brazilian fuel alcohol yeast strain for Scotch whisky fermentations

Traditionally, distilling companies in Scotland have employed a very limited number of yeast strains in the production of alcohol for Scotch whiskies. Recent changes such as the decline in availability of brewers’ yeast as a secondary yeast strain and the availability of yeast in different formats (e.g., dried and cream yeast as alternatives to compressed yeast) have promoted interest in alternative Scotch whisky distilling yeasts. In previous work, we investigated different strains of yeasts, specifically Brazilian yeasts which had been isolated from and used in fuel alcohol distilleries. One of the Brazilian yeasts (CAT 1) showed a comparable fermentation performance and superior stress tolerance compared with a standard commercial Scotch whisky distilling yeast (M Type). The Brazilian CAT 1 yeast isolate was further assessed in laboratory scale fermentations and subsequent new make spirit was subjected to sensory analyses. The spirits produced using the Brazilian strain had acceptable flavour profiles and exhibited no sensory characteristics that were atypical of Scotch whisky new make spirit. This study highlights the potential of exploiting yeast biodiversity in traditional Scotch whisky distillery fermentation processes

The interferometric baselines and GRAVITY astrometric error budget

GRAVITY is a new generation beam combination instrument for the VLTI. Its goal is to achieve microarsecond astrometric accuracy between objects separated by a few arcsec. This $10^6$ accuracy on astrometric measurements is the most important challenge of the instrument, and careful error budget have been paramount during the technical design of the instrument. In this poster, we will focus on baselines induced errors, which is part of a larger error budget.Comment: SPIE Meeting 2014 -- Montrea

A Cellular Automata Model for Citrus Variagated Chlorosis

A cellular automata model is proposed to analyze the progress of Citrus Variegated Chlorosis epidemics in S\~ao Paulo oranges plantation. In this model epidemiological and environmental features, such as motility of sharpshooter vectors which perform L\'evy flights, hydric and nutritional level of plant stress and seasonal climatic effects, are included. The observed epidemics data were quantitatively reproduced by the proposed model varying the parameters controlling vectors motility, plant stress and initial population of diseased plants.Comment: 10 pages, 10 figures, Scheduled tentatively for the issue of: 01Nov0

Supersymmetry and the Chiral Schwinger Model

We have constructed the N=1/2 supersymmetric general Abelian model with asymmetric chiral couplings. This leads to a N=1/2 supersymmetrization of the Schwinger model. We show that the supersymmetric general model is plagued with problems of infrared divergence. Only the supersymmetric chiral Schwinger model is free from such problems and is dynamically equivalent to the chiral Schwinger model because of the peculiar structure of the N=1/2 multiplets.Comment: one 9 pages Latex file, one ps file with one figur

Constrained titanohematite formation at BTO/Fe interfaces deposited by RF-sputtering

The usage of heterostructures of ferromagnetic and ferroelectric materials, as a means of achieving magnetoelectric multiferroic coupling, is a widely used approach which has been showing promising results. Along this line of thought, the deposition of BaTiO3 and Fe multilayers on LaAlO3, MgO, Al2O3 and SrTiO3 substrates using RF-magnetron sputtering was carried out to study its viability to produce magnetoelectric heterostructures. It is shown that each substrate constrains the growth of the deposited thin films, even for the same deposition conditions. This is clearly seen through the magnetic properties of the thin film, mainly after performing a 900 °C thermal annealing in air. The thermal annealing results in the creation of iron oxides specific of each one of the substrates where the deposition took place.publishe