534 resultados para Doyle, Plínio
Resumo:
This paper describes the use of 800nm femtosecond infrared (IR) and 248nm nanosecond ultraviolet (UV) laser radiation in performing ablative micromachining of parylene-C on SiO2 substrates for the patterning of human hNT astrocytes. Results are presented that support the validity of using IR laser ablative micromachining for patterning human hNT astrocytes cells while UV laser radiation produces photo-oxidation of the parylene-C and destroys cell patterning. The findings demonstrate how IR laser ablative micromachining of parylene-C on SiO2 substrates can offer a low cost, accessible alternative for rapid prototyping, high yield cell patterning.
Resumo:
Fire is a worldwide phenomenon that appears in the geological record soon after the appearance of terrestrial plants. Fire influences global ecosystem patterns and processes, including vegetation distribution and structure, the carbon cycle, and climate. Although humans and fire have always coexisted, our capacity to manage fire remains imperfect and may become more difficult in the future as climate change alters fire regimes. This risk is difficult to assess, however, because fires are still poorly represented in global models. Here, we discuss some of the most important issues involved in developing a better understanding of the role of fire in the Earth system.
Resumo:
A number of case studies of large, transient, field-aligned ion flows in the topside ionosphere at high-latitudes have been reported, showing that these events occur during periods of frictional heating and/or intense particle precipitation. This study examines the frequency of occurrence of such events for the altitude range 200–500 km, based on 3 years of incoherent scatter data. Correlations of the upgoing ion flux at 400 km with ion and electron temperatures at lower altitudes are presented, together with a discussion of possible mechanisms for the production of such large flows. The influence of low-altitude electron precipitation on the production of these events is also considered.
Resumo:
Group Exhibition curated by Cedar Lewisohn. Contributors: Caroline Achaintre, Edwin Burdis, Slawomir Czajkowski (Zbiok), Shaun Doyle and Mally Mallinson, Ruth Ewan, Andrew Gilbert, Joel Gray, Tod Hanson, Geoffrey Ireland, kennardphillipps, Cedar Lewisohn (curator), Kieron Livingstone and Ian Allison, Alexis Milne, Laura Oldfield Ford, Max Reeves, Clunie Reid, John Russell, Francis Thorburn, Vicky Wright.
Resumo:
Sampling protocols for detecting Salmonella on poultry differ among various countries. In the United States, the U.S. Department of Agriculture Food Safety and Inspection Service dictates that whole broiler carcasses should be rinsed with 400 ml of 1% buffered peptone water, whereas in the European Union 25-g samples composed of neck skin from three carcasses are evaluated. The purpose of this study was to evaluate a whole carcass rinse (WCR) and a neck skin excision (NS) procedure for Salmonella and Escherichia coli isolation from the same broiler carcass. Carcasses were obtained from three broiler processing plants. The skin around the neck area was aseptically removed and bagged separately from the carcass, and microbiological analysis was performed. The corresponding carcass was bagged and a WCR sample was evaluated. No significant difference (alpha <= 0.05) in Salmonella prevalence was found between the samples processed by the two methods, but both procedures produced many false-negative Salmonella results. Prechill, 37% (66 carcasses), 28% (50 carcasses), and 51% (91 carcasses) of the 180 carcasses examined were positive for Salmonella by WCR, NS, and both procedures combined, respectively. Postchill, 3% (5 carcasses), 7% (12 carcasses), and 10% (17 carcasses) of the 177 carcasses examined were positive for Salmonella by the WCR, NS, and combination of both procedures, respectively. Prechill, E. coli plus coliform counts were 3.0 and 2.6 log CFU/ml by the WCR and NS methods, respectively. Postchill. E. coli plus coliform counts were 1.7 and 1.4 log CFU/ml by the WCR and NS methods, respectively.
Resumo:
Cerium doped yttrium aluminate perovskite YAlO(3) (YAP) powders are pursued as interesting alternatives to bulk crystals for application in scintillating devices. The emissions of these materials in the near-UV and visible spectral regions originate from electric dipole transitions between 4f and 5d energy levels of Ce(3+) and largely depend on the environment occupied by the ion. In search for improved synthesis conditions that can lead to phase pure powders with optimized structural and spectroscopic characteristics, in this work we have employed the polymeric precursor (Pechini) method to prepare crystalline and amorphous YAP:Ce powders doped with 1-10 mol% Ce(3+). Interesting composite materials were also obtained by dispersing some of the YAP:Ce powders in silica xerogels. A comparative structural and spectroscopic study of all the samples was done by XRD, FT-IR, emission, excitation and excited state lifetime measurements. In agreement with previous reports, excitation at 296 nm results in intense emission in the range 315-425 nm with an average decay time of 30 ns. (c) 2010 Elsevier B.V. All rights reserved.
Resumo:
I consider the case for genuinely anonymous web searching. Big data seems to have it in for privacy. The story is well known, particularly since the dawn of the web. Vastly more personal information, monumental and quotidian, is gathered than in the pre-digital days. Once gathered it can be aggregated and analyzed to produce rich portraits, which in turn permit unnerving prediction of our future behavior. The new information can then be shared widely, limiting prospects and threatening autonomy. How should we respond? Following Nissenbaum (2011) and Brunton and Nissenbaum (2011 and 2013), I will argue that the proposed solutions—consent, anonymity as conventionally practiced, corporate best practices, and law—fail to protect us against routine surveillance of our online behavior. Brunton and Nissenbaum rightly maintain that, given the power imbalance between data holders and data subjects, obfuscation of one’s online activities is justified. Obfuscation works by generating “misleading, false, or ambiguous data with the intention of confusing an adversary or simply adding to the time or cost of separating good data from bad,” thus decreasing the value of the data collected (Brunton and Nissenbaum, 2011). The phenomenon is as old as the hills. Natural selection evidently blundered upon the tactic long ago. Take a savory butterfly whose markings mimic those of a toxic cousin. From the point of view of a would-be predator the data conveyed by the pattern is ambiguous. Is the bug lunch or potential last meal? In the light of the steep costs of a mistake, the savvy predator goes hungry. Online obfuscation works similarly, attempting for instance to disguise the surfer’s identity (Tor) or the nature of her queries (Howe and Nissenbaum 2009). Yet online obfuscation comes with significant social costs. First, it implies free riding. If I’ve installed an effective obfuscating program, I’m enjoying the benefits of an apparently free internet without paying the costs of surveillance, which are shifted entirely onto non-obfuscators. Second, it permits sketchy actors, from child pornographers to fraudsters, to operate with near impunity. Third, online merchants could plausibly claim that, when we shop online, surveillance is the price we pay for convenience. If we don’t like it, we should take our business to the local brick-and-mortar and pay with cash. Brunton and Nissenbaum have not fully addressed the last two costs. Nevertheless, I think the strict defender of online anonymity can meet these objections. Regarding the third, the future doesn’t bode well for offline shopping. Consider music and books. Intrepid shoppers can still find most of what they want in a book or record store. Soon, though, this will probably not be the case. And then there are those who, for perfectly good reasons, are sensitive about doing some of their shopping in person, perhaps because of their weight or sexual tastes. I argue that consumers should not have to pay the price of surveillance every time they want to buy that catchy new hit, that New York Times bestseller, or a sex toy.
Resumo:
Trata-se de um estudo exploratório/explanatório que visa avaliar a convergência entre a percepção de atratividade do mercado hoteleiro brasileiro e o posicionamento estratégico para negócios das grandes cadeias multinacionais de hotéis na avaliação de seus altos dirigentes. A pesquisa está inserida no contexto das estratégias de negócios internacionais e da expansão global hoteleira, tendo o Brasil como alvo.
Resumo:
Desvenda o Modus Operandi dos Albergues da Juventude do Brasil como funcionam, como se inserem no contexto nacional e mundial, atrativos mercadológicos, estruturas organizacional e hotelaria básica da indústria de hospitalidade, marketing mix, planejamento estratégico etc. Sob o prisma dos conceitos do Marketing de Hospitalidade
Resumo:
O presente trabalho tem por objetivo retratar e analisar a distribuição de autoveículos fabricados no País e sua forma de organização no mercado brasileiro. Em todos os países onde a produção automobilística possui expressão econômica, as empresas montadoras implantaram sistemas de distribuição de veículos. Essas empresas são na sua maioria, grupos empresariais multinacionais que, através de orientações normativas emanadas das matrizes, dirigem o comportamento comercial e operacional de suas subsidiárias espalhadas pelo mundo, impondo-lhes critérios padronizados de atuação, o que tem reflexos em todos os níveis do mercado automobilístico. Assim, as subsidiárias e as próprias empresas montadoras nacionais vão conceber de maneira bastante semelhante, o sentido e o funcionamento da distribuição de veículos, apesar das diferenças existentes entre os mercados que operam e os Contratos de Concessão que regulam as relações entre montadoras e distribuidoras.
Resumo:
O presente trabalho, além de pretender apresentar uma contribuição para o debate em torno do papel do Estado na economia, analisa algumas alternativas de organização e de eficiência econômica para o setor petróleo no Brasil, na hipótese de flexibilização do monopólio estatal.
Resumo:
A configuração desta dissertação pretende, como objetivo principal, a análise fundamentada dos atributos essenciais para a auto-sustentação de uma concessionária, monopolista, sujeita à regulamentação, mediante a aplicação de uma metodologia de determinação dos seus custos marginais inerentes ao processo de geração, transmissão e distribuição de energia elétrica.
Resumo:
De início é interessante esclarecer que a presente dissertação constitui-se de monografia que compila parte da literatura existente sobre a formação econômica do setor sucroalcooleiro e busca harmonizar as informações, opiniões e análises aí contidas,dentro de uma visão histórica dando destaque ao período recente últimos 20 anos , e ao Programa Nacional do Alcool - Proálcool ou PNA
Resumo:
No presente trabalho iremos nos preocupar com as circunstâncias sob as quais os parâmetros de eficiência não predominaram no modelo habitacional do país durante o período em que este conviveu com um sistema habitacional formalmente estruturado, que se inicia em 1964 e permanece até o presente momento, dedicando especial atenção aos parâmetros de funcionamento atuais. Buscaremos analisar formalmente as causas das distorções, suas consequências em termos qualitativos e quantitativos e eventuais propostas de superação das dificuldades.