Local Isometric immersions of pseudo-spherical surfaces and evolution equations

The class of differential equations describing pseudo-spherical surfaces, first introduced by Chern and Tenenblat [3], is characterized by the property that to each solution of a differential equation, within the class, there corresponds a 2-dimensional Riemannian metric of curvature equal to $-1$. The class of differential equations describing pseudo-spherical surfaces carries close ties to the property of complete integrability, as manifested by the existence of infinite hierarchies of conservation laws and associated linear problems. As such, it contains many important known examples of integrable equations, like the sine-Gordon, Liouville and KdV equations. It also gives rise to many new families of integrable equations. The question we address in this paper concerns the local isometric immersion of pseudo-spherical surfaces in ${\bf E}^{3}$ from the perspective of the differential equations that give rise to the metrics. Indeed, a classical theorem in the differential geometry of surfaces states that any pseudo-spherical surface can be locally isometrically immersed in ${\bf E}^{3}$. In the case of the sine-Gordon equation, one can derive an expression for the second fundamental form of the immersion that depends only on a jet of finite order of the solution of the pde. A natural question is to know if this remarkable property extends to equations other than the sine-Gordon equation within the class of differential equations describing pseudo-spherical surfaces. In an earlier paper [11], we have shown that this property fails to hold for all other second order equations, except for those belonging to a very special class of evolution equations. In the present paper, we consider a class of evolution equations for $u(x,t)$ of order $k\geq 3$ describing pseudo-spherical surfaces. We show that whenever an isometric immersion in ${\bf E}^3$ exists, depending on a jet of finite order of $u$, then the coefficients of the second fundamental forms are functions of the independent variables $x$ and $t$ only.Comment: Fields Institute Communications, 2015, Hamiltonian PDEs and Applications, pp.N

Low temperature upcycling of vitreous byproduct of the MSW plasma processing into multifunctional porous glass-ceramics

Mixtures of glass residues, deriving from the plasma processing of municipal solid waste (\u2018Plasmastone\u2019), and recycled glasses have been already converted into highly porous glass-ceramics by application of an inorganic gel casting technique (foaming, by intensive mechanical stirring, of alkali activated slurries) followed by sintering at 1000\ub0C. The full potential of recycled glass, however, has not been disclosed yet. The present investigation, in fact, demonstrates that boro-alumino-silicate glass, from discarded pharmaceutical vials, may allow for sintering of cellular glass-ceramics at particularly low temperature, i.e. at 800\ub0C. The full stabilisation of heavy metals from Plasmastone (already assessed for treatments at 1000\ub0C) is not compromised, whereas the low processing temperatures favour the separation of magnetite, in turn imparting new functionalities (e.g. electromagnetic shielding) to waste-derived glass-ceramic foams

Case studies of up-cycling of partially crystallized ceramic waste in highly porous glass-ceramics

Highly porous glass-based materials represent a solution for thermal insulation. However, the manufacturing costs still affect their extensive use. The present investigation proposes savings in the production of foams by use of discarded materials, such as polishing residue or vitrified asbestos-containing waste, minimizing additives and processing temperatures. Aqueous suspensions of powders, mixed with soda-lime glass, underwent progressive gelation due to alkali activation. An extensive foaming was determined by mechanical stirring, with the help of a surfactant. Finally, a firing step yielded foams exhibiting excellent strength-to-density ratios, due to densification and control of crystal phases, both supported by the glass addition

Device-independent bounds for Hardy's experiment

In this Letter we compute an analogue of Tsirelson's bound for Hardy's test of nonlocality, that is, the maximum violation of locality constraints allowed by the quantum formalism, irrespective of the dimension of the system. The value is found to be the same as the one achievable already with two-qubit systems, and we show that only a very specific class of states can lead to such maximal value, thus highlighting Hardy's test as a device-independent self-test protocol for such states. By considering realistic constraints in Hardy's test, we also compute device-independent upper bounds on this violation and show that these bounds are saturated by two-qubit systems, thus showing that there is no advantage in using higher-dimensional systems in experimental implementations of such test.Comment: 4 pages, 2 figure

Sistemas de cultivo e custos de produção de arroz irrigado em Iguatu (CE), na safra 2004/2005.

O presente trabalho teve como objetivos: (a) caracterizar os sistemas de cultivo de arroz irrigado praticados em Iguatu (CE); e (b) estimar os custos de produção destes sistemas de cultivo na safra 2004/2005.bitstream/CNPAF/23589/1/comt_102.pd

The quantum maxima for the basic graphs of exclusivity are not reachable in Bell scenarios

A necessary condition for the probabilities of a set of events to exhibit Bell nonlocality or Kochen-Specker contextuality is that the graph of exclusivity of the events contains induced odd cycles with five or more vertices, called odd holes, or their complements, called odd antiholes. From this perspective, events whose graph of exclusivity are odd holes or antiholes are the building blocks of contextuality. For any odd hole or antihole, any assignment of probabilities allowed by quantum mechanics can be achieved in specific contextuality scenarios. However, here we prove that, for any odd hole, the probabilities that attain the quantum maxima cannot be achieved in Bell scenarios. We also prove it for the simplest odd antiholes. This leads us to the conjecture that the quantum maxima for any of the building blocks cannot be achieved in Bell scenarios. This result sheds light on why the problem of whether a probability assignment is quantum is decidable, while whether a probability assignment within a given Bell scenario is quantum is, in general, undecidable. This also helps to undertand why identifying principles for quantum correlations is simpler when we start by identifying principles for quantum sets of probabilities defined with no reference to specific scenarios.Comment: 8 pages, 4 figure

Auditory Processing Performance of the Middle-Aged and Elderly: Auditory or Cognitive Decline?

BACKGROUND: Despite the well-established relationship between aging and auditory processing decline, identifying the extent to which age effect is the main factor on auditory processing performance remains a great challenge due to the co-occurrence of age-related hearing loss and age-related cognitive decline as potential confounding factors. PURPOSE: To investigate the effects of age-related hearing loss and working memory on the clinical evaluation of auditory processing of middle-aged and elderly. RESEARCH DESIGN: Cross-sectional study. STUDY SAMPLE: A total of 77 adults between 50 and 70 yr of age were invited to participate in the study. DATA COLLECTION AND ANALYSIS: The participants were recruited from a larger study that focused on the assessment and management of sensory and cognitive skills in elderly participants. Only participants with normal hearing or mild-to-moderate age-related hearing loss, with no evidence of cognitive, psychological, or neurological conditions were included. Speech-in-noise, dichotic digit, and frequency pattern tests were conducted as well as a working memory test. The hearing loss effect was investigated using an audibility index, calculated from the audiometric threshold. The performance on the digit span test was used to investigate working memory effects. Both hearing loss and working memory effects were investigated via correlation and regression analyses, partialling out age effects. The significance level was set at p < 0.05. RESULTS: The results demonstrated that, while hearing loss was associated to the speech-in-noise performance, working memory was associated to the frequency pattern and dichotic digit performances. Regression analyses confirmed the relative contribution of hearing loss to the variance in speech-in-noise and working memory test to the variance in frequency pattern and dichotic digit test performance. CONCLUSIONS: The performance decline of the elderly in auditory processing tests may be partially attributable to the working memory performance and, consequently, to the cognitive decline exhibited by this population. Mild-to-moderate hearing loss seems to affect performance on specific auditory processing tasks, such as speech in noise, reinforcing the idea that auditory processing disorder in the elderly might also be associated to auditory peripheral deficits

Cooperação técnica entre Japão e Brasil e entre Brasil e Timor Leste em perspectiva comparada

O trabalho apresenta análise comparativa de casos de cooperação técnica realizada entre Brasil e dois países de diferentes níveis de desenvolvimento da Ásia, região considerada como um dos últimos grandes espaços para a consolidação do perfil global brasileiro. Verificaram-se semelhanças e diferenças entre a cooperação fornecida pelo Japão ao Brasil desde meados do Século XX e a cooperação brasileira em Timor Leste no Século XXI, com base em discursos apresentados pelos doadores em políticas externas relativas a cooperação técnica internacional, bem como nos marcos jurídico e operacional da cooperação, especialmente na forma de acordos e projetos, com vistas a analisar em que medida a cooperação técnica brasileira pode apresentar alternativas a modelos de países avançados como o Japão, no sentido da promoção do desenvolvimento com esforços cooperativos caracterizados como efetivas operações conjuntas

Nipo-brasileiros em Paracatu: Contribuições da presença japonesa para o desenvolvimento em uma cidade de herança lusófona

O recente desenvolvimento do município de Paracatu pode ser atribuído a diversos fatores, entre os quais o incremento agrícola obtido com o Programa Nipo-Brasileiro para o Desenvolvimento dos Cerrados (PRODECER), implantado entre 1978 e 2001, com o objetivo de tornar produtivo o solo do Cerrado, bioma presente em várias localidades do Brasil, a exemplo de Paracatu, cujo território é explorado para a atividade mineradora desde o Século XVIII, quando se registra o início da história paracatuense.Este ensaio, cujas imagens retratam contribuições da colônia japonesa para o progresso econômico e social de Paracatu, baseia-se em artigo produzido como atividade da disciplina Estudos Luso-Orientais e apresentado na Conferência Internacional Interfaces da Lusofonia, realizada na Universidade do Minho, Lisboa, Portugal, em 2013. A construção deste trabalho foi motivada pela celebração dos 120 anos de relacionamento ente Brasil e Japão em 2015, quando homenagem será outorgada a ilustres nipo-brasileiros do Município

Índice de performance da sustentabilidade municipal : uma nova proposta metodológica para a avaliação socioeconômica e ambiental dos municípios brasileiros

Dissertação (mestrado)—Universidade de Brasília, Centro de Desenvolvimento Sustentável, Programa de Pós-Graduação em Desenvolvimento Sustentável, 2017.O desenvolvimento sustentável, em termos gerais, é uma nova alternativa de desenvolvimento socioeconômico baseado no conceito do triple bottom line. A consolidação do tema da sustentabilidade inspirou e incitou doutrinas e teorias econômicas e sociológicas, além de demandas por políticas de proteção ambiental. Então surgiram as primeiras propostas de construção de indicadores ambientais. Os indicadores de sustentabilidade têm a capacidade de comunicar o progresso de uma atividade ou local em relação a uma meta. A sua representação deve ser clara e objetiva o suficiente para retratar o mais próximo da realidade e prever possíveis consequências. A construção de indicadores de sustentabilidade é complexa, pois a representação da realidade e da relação do meio ambiente com a sociedade envolve uma rede ampla de perspectivas e fatores. A criação de um índice busca também preencher as falhas reconhecidas em outras metodologias mais aplicadas. Com isso, esse estudo tem por objetivo propor um novo índice de sustentabilidade denominado Índice de Performance da Sustentabilidade Municipal – IPSM, cuja intenção é apresentar uma proposta metodológica, cuja aplicação seja adequada para os municípios brasileiros, independentemente de seu porte, para uma comparação em escala temporal do seu desempenho. Para o método, realiza-se uma análise dos indicadores relativos à quatro dimensões, incluídas em índices temáticos, sendo que, os indicadores possuem pesos diferentes para cada município. Esses pesos são atribuídos de acordo com os aspectos identificados por stakeholders, referentes às características do município. Essa identificação é realizada por meio de um questionário, denominado “Questionário de ponderação”, aplicado a gestores ou especialistas da área ambiental envolvidos no processo de tomada de decisão do município para que então seja aplicada análise hierárquica (AHP) para cálculo das importâncias. Os valores dos indicadores são normalizados dentro de escala percentis. O IPSM foi aplicado para dois municípios: Paracatu-MG e AnápolisGO, mostrando diferenças relativamente significativas entre a performance de sustentabilidade, correspondendo justamente às suas diferenças demográficas, sociais, ambientais, institucionais e econômicas.The sustainable development is a new socio-economic development alternative, based on the triple bottom line concept. The consolidation of the theme of sustainability has inspired and stimulated economic and sociological doctrines and theories, and demands for environmental protection policies. So, came the first proposals to build environmental indicators. Sustainability indicators have the ability to communicate the progress of an activity in relation to a performance. The representation must be clear and objective enough to represent the reality and predict possible consequences. The construction of sustainability indicators is complex, since the representation of reality and the relationship between the environment and society involves a wide network of perspectives. The creation of an index also seeks to fill in the flaws recognized in other more applied methodologies. The objective of this study is to propose a new sustainability index called the Municipal Sustainability Performance Index (IPSM), which intends to present a methodological proposal, which is appropriate for Brazilian cuties, for all sizes, for a comparison in time scale of their performance. For the method, an analysis of the indicators related to four dimensions, included in thematic indexes, is carried out. So, the indicators have different weights for each city. These weights are attributed according to the aspects identified by stakeholders, referring to the characteristics of the municipality. This identification is carried out by means of a questionnaire, called "Weighting Questionnaire", applied to environmental managers or experts involved in the municipal decision-making process so that hierarchical analysis (AHP) is applied to calculate the amounts. The values of the indicators are normalized into percentile scales. The IPSM was applied to two cities: Paracatu-MG and Anápolis-GO, showing relatively significant differences between sustainability performance, corresponding precisely to their demographic, social, environmental, institutional and economic differences