574 research outputs found
Discrete squeezed states for finite-dimensional spaces
We show how discrete squeezed states in an -dimensional phase space
can be properly constructed out of the finite-dimensional context. Such
discrete extensions are then applied to the framework of quantum tomography and
quantum information theory with the aim of establishing an initial study on the
interference effects between discrete variables in a finite phase-space.
Moreover, the interpretation of the squeezing effects is seen to be direct in
the present approach, and has some potential applications in different branches
of physics.Comment: 16 pages; 3 figure
The prism of the public sphere: The COP15 coverage by the Brazilian media system
Current studies of political communication offer valuable contributions to assessing and measuring mediated deliberation. But in our understanding of the news media's role in a deliberative system a number of questions remain unanswered, especially concerning problems posed by social complexity. This paper aims to contribute to closing this gap by conducting an empirical analysis on how distinct contributions to public deliberation – namely the provision of publicity and intelligibility – are articulated via outputs offered by different types of media outlets, specifically in the case of the Brazilian coverage of the 15th UN’s Climate Change Conference (COP15). Our results suggest that this coverage seems to have fostered citizens to search for more information about this Conference and augmented the visibility of UN’s climate negotiations. This gives support to the idea that news media system works like a prism of the public sphere, promoting accountability of complex governance processes by offering information and public scrutiny adequate for a heterogeneous citizenry
Effect of controlled traffic farming on energy saving in Australian grain cropping systems
Controlled traffic farming (CTF) is a system in which all machinery has the same or modular working and track widths so that field traffic can be confined to the least possible area of compacted permanent traffic lanes. In well-designed CTF systems permanent traffic lanes usually occupy less than 15% of cropped area, and this has been widely adopted in Australia. CTF is a practical and cost-effective facilitator of no-tillage farming, and the basis for more precise cropping systems. Controlled traffic systems are often claimed to reduce power and fuel requirements of cropping operations, because motion resistance to traffic should be less on permanent lanes, and draft requirement of tilling or seeding should be less in non-compacted soil. Experimental work was conducted to assess the effects of tractor wheel compaction on the energy requirements of soil-engaging operations, particularly, during tillage and planting. Preliminary results from this investigation indicate that on average the draft of tillage sweeps, planter openers, and chisel tines increased by approximately 35%, 37%, and 54%, respectively, when positioned behind a tractor wheel
Comportamento de cultivares de milho verde em ecossistema de várzea e terra firme no Estado do Amazonas.
Genótipos de milho com potencial para comercialização no estágio verde de maturação no Estado do Amazonas.
Resumo: O milho no estágio verde de maturação - milho verde - representa uma alternativa viável de produção e agregação de valor para pequenas propriedades no Amazonas. Com o objetivo de avaliar a adaptabilidade de genótipos e verificar qual a melhor época para colheita para os diferentes cultivares, foi conduzido um experimento em Latossolo Amarelo distrófico no município de Manaus, utilizando o delineamento experimental de blocos casualizados com oito tratamentos e quatro repetições. Os tratamentos foram definidos por oito genótipos de milho, sendo seis variedades (Sol da Manhã, BR 106, BR 5110, Saracura, Cativerde, AG 1051, HTMV1 e Campeão) e dois híbridos (HTMV1 e AG 1051) que foram colhidos em cinco épocas diferentes e avaliados parâmetros fitotécnicos, organolépticos e mercadológicos dos diferentes genótipos. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Duncan a 5% de probabilidade. Os resultados evidenciaram variações no estande, altura de planta, altura de inserção das espigas, diâmetro do colmo, número de espigas totais, número de espigas comerciais, comprimento da espiga, diâmetro da espiga, número de carreiras, número de fileiras, brix e cor dos grãos em função dos cultivares utilizados. O número de espigas comerciais foi maior para os genótipos AG 1051 e BR 5110, com 42708 e 38542 espigas comerciais ha-1, respectivamente. Considerando o preço da "mão de milho", nome dado a 50 espigas comerciais de milho verde comercializada no Amazonas, custando R7,21), o produtor teria uma renda bruta variando de R 12.812,00
Lattice-point enumerators of ellipsoids
Minkowski's second theorem on successive minima asserts that the volume of a
0-symmetric convex body K over the covolume of a lattice \Lambda can be bounded
above by a quantity involving all the successive minima of K with respect to
\Lambda. We will prove here that the number of lattice points inside K can also
accept an upper bound of roughly the same size, in the special case where K is
an ellipsoid. Whether this is also true for all K unconditionally is an open
problem, but there is reasonable hope that the inductive approach used for
ellipsoids could be extended to all cases.Comment: 9 page
Sobre uma coluna vertebral de um titanossaurídeo (Dinosauria, Sauropoda) do grupo Bauru, Neocretáceo do Brasil
A new titanosaurid dinosaur from the Late Cretaceous continental deposits of the Bauru Group is described. Trigonosaurus pricei n.gen., n.sp., is based on two specimens, both collected at the Caieira Quarry near Peirópolis, Minas Gerais. The holotype consists of the five most posterior cervical vertebrae, 10 dorsals, six sacrals and the left ilium (MCT 1488-R). The second specimen (paratype) consists of 10 caudal vertebrae that according to a quarry map, were found isolated but show a similar morphology and compatible size suggesting that they belonged to one individual (MCT 1719-R). Trigonosaurus pricei is diagnosed by a combination of characters such as elongated cervicals and middorsals, dorsal vertebrae 9 and 10 with incipient postzygodiapophyseal lamina and transverse processes well developed throughout the sequence formed by anterior and medial caudals. The occurrence of this new taxon indicates a higher diversity of titanosaurids in the Brazil during the Cretaceous period.Um novo titanossaurídeo procedente dos depósitos continentais do grupo Bauru (Neocretáceo) é descrito. Trigonosaurus pricei n.gen., n.sp. é baseado em dois exemplares coletados na localidade Caieira na região de Peirópolis, Minas Gerais. O holótipo é composto das últimas cinco vértebras cervicais, 10 vértebras dorsais, seis sacrais e o ílio esquerdo (MCT 1488-R). O segundo exemplar (parátipo) é formado por 10 vértebras caudais que, de acordo com um mapa da escavação, foram encontradas isoladas, mas apresentam o mesmo padrão morfológico e um tamanho compatível, sendo, deste modo, consideradas como pertencentes a um mesmo indivíduo (MCT 1719-R). Trigonosaurus pricei é diagnosticado por uma combinação de caracteres tais como vértebras cervicais e dorsais médias alongadas, vértebras dorsais 9 e 10 com uma incipiente lâmina diapopós-zigapofisiária e processos transversos bem desenvolvidos por toda seqüência anterior e média da série caudal. A ocorrência deste novo táxon demonstra a existência de uma maior diversidade de titanosaurídeos no Brasil durante o período Cretáceo
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