As implicações do consumo na preservação do ambiente

A sociedade pós-moderna é tendencialmente a sociedade do desperdício, em que coexistem a mais atroz miséria e a opulência mais ostensiva. A sociedade pós-moderna é marcada por profundas assimetrias sociais em que se contrapõem pungentes quadros de escassez a deprimentes situações de abundância, dominadas pelo supérfluo e pelo sumptuário. A sociedade pós-moderna aparta-se dos modelos de equilíbrio e dos quadros de racionalidade que deveriam constituir as coordenadas de um desenvolvimento económico e social sustentado. A concentração da riqueza em um escasso número amplia qual mancha ou nódoa a franja dos excluídos. Os níveis de consumo disparam em estratos determinados e comprimem-se nos mais desfavorecidos. O fenómeno é, porém, preocupante porque tais índices são dominados por estranhos factores de que as estratégias mercadológicas se socorrem no afã de se criarem necessidades artificiais e de se avolumar o desperdício. O consumo de produtos, em particular, tem sido dominado pela reprodução insaciável do número de produtos à disposição do público

Dynamic PCBM:Dimer Population in Solar Cells under Light and Temperature Fluctuations

Photoinduced dimerization of phenyl‐C61‐butyric acid methyl ester (PCBM) has a significant impact on the stability of polymer:PCBM organic solar cells (OSCs). This reaction is reversible, as dimers can be thermally decomposed at sufficiently elevated temperatures and both photodimerization and decomposition are temperature dependent. In operando conditions of OSCs evidently involve exposure to both light and heat, following periodic diurnal and seasonal profiles. In this work, the kinetics of dimer formation and decomposition are examined and quantified as a function of temperature, light intensity, blend composition, and time. The activation energy for photodimerization is estimated to be 0.021(3) eV, considerably smaller than that for decomposition (0.96 eV). The findings are benchmarked with a variety of conjugated polymer matrices to propose a descriptive dynamic model of PCBM:dimer population in OSCs, and a framework is proposed to rationalize its interplay with morphology evolution and charge quenching. The model and parameters enable the prediction of the dynamic and long‐term PCBM:dimer populations, under variable temperature and light conditions, which impact the morphological stability of OSCs

Exotic looped trajectories via quantum marking

We provide an analytical and theoretical study of exotic looped trajectories (ELTs) in a double-slit interferometer with quantum marking. We use an excited Rydberg-like atom and which-way detectors such as superconducting cavities, just as in the Scully-Englert-Walther interferometer. We indicate appropriate conditions on the atomic beam or superconducting cavities so that we determine an interference pattern and fringe visibility exclusive from the ELTs. We quantitatively describe our results for Rubidium atoms and propose this framework as an alternative scheme to the double-slit experiment modified to interfere only these exotic trajectories.Comment: 10 pages, 5 figure

Perguntas retóricas na entrevista política: um estudo de caso

The aim of this study is show how rethoric questions are asked by speakers. This research has as investigation corpus two interviews granted by politicians Luís Henrique and Salvador Zimbaldi to journalist Heródoto Barbeiro. The used method is the inductive, because, in this work, the starting-point is to analyse rethoric questions in selected corpus, in order to describe the contexts in which theses questions are asked. Based on the Interactive Sociolinguistics and Textual Linguistics presuppositions, this research is developed by the Speech Analysis (guided by ethnomethodology) technics. This article contains the following observations: 1) when interviewees ask a rethoric question, they intend to adapt themselves to interactive moment established by interviewer; 2) when interviewer ask this kind of question, he purposes to make some accusation for interviewees, with a view to control the interaction. We have concluded rethoric questions are based on pragmatic connection between a seeming question and an answer. Through this link, it happens a structural recomposition of adjacent pair, term used by Schegloff and Sacks (1973).A finalidade deste estudo é mostrar de que maneira as perguntas retóricas são formuladas pelos falantes. Utilizam-se como corpus duas entrevistas concedidas pelos políticos Luís Henrique e Salvador Zimbaldi ao jornalista Heródoto Barbeiro. O método empregado é o indutivo, porque, neste trabalho, adota-se como ponto de partida a análise das perguntas retóricas presentes no corpus, com o propósito de descrever os contextos nos quais essas perguntas são formuladas. A fundamentação teórica provém de postulados concernentes à Sociolingüística Interacional e à Lingüística Textual. Metodologicamente, a pesquisa deixa-se conduzir pela Análise da Conversação de caráter etnográfico. Este artigo contém as seguintes observações: 1) quando os entrevistados elaboram uma pergunta retórica, pretendem adaptar-se ao momento interativo estabelecido pelo entrevistador; 2) quando o entrevistador formula esse tipo de pergunta, objetiva dirigir alguma acusação aos entrevistados, a fim de manter o controle da interação. Pode-se concluir que as perguntas retóricas se baseiam no enlace pragmático entre uma aparente pergunta e uma resposta, união por meio da qual se institui uma recomposição estrutural do par adjacente, termo utilizado por Schegloff & Sacks (1973). Abstract: The aim of this study is show how rethoric questions are asked by speakers. This research has as investigation corpus two interviews granted by politicians Luís Henrique and Salvador Zimbaldi to journalist Heródoto Barbeiro. The used method is the inductive, because, in this work, the starting-point is to analyse rethoric questions in selected corpus, in order to describe the contexts in which theses questions are asked. Based on the Interactive Sociolinguistics and Textual Linguistics presuppositions, this research is developed by the Speech Analysis (guided by ethnomethodology) technics. This article contains the following observations: 1) when interviewees ask a rethoric question, they intend to adapt themselves to interactive moment established by interviewer; 2) when interviewer ask this kind of question, he purposes to make some accusation for interviewees, with a view to control the interaction. We have concluded rethoric questions are based on pragmatic connection between a seeming question and an answer. Through this link, it happens a structural recomposition of adjacent pair, term used by Schegloff and Sacks (1973). Keywords: Rethoric questions. Interview. Interaction

Error Control Coding Techniques for Space and Satellite Communications

Bootstrap Hybrid Decoding (BHD) (Jelinek and Cocke, 1971) is a coding/decoding scheme that adds extra redundancy to a set of convolutionally encoded codewords and uses this redundancy to provide reliability information to a sequential decoder. Theoretical results indicate that bit error probability performance (BER) of BHD is close to that of Turbo-codes, without some of their drawbacks. In this report we study the use of the Multiple Stack Algorithm (MSA) (Chevillat and Costello, Jr., 1977) as the underlying sequential decoding algorithm in BHD, which makes possible an iterative version of BHD

Pacientes com glaucoma e blefaroespasmo essencial: relato de casos

Essential blepharospasm is a facial dystonia characterized by spontaneous, spasmodic and involuntary contractions of the eyelid muscles. In advanced cases, blepharospasm patients develop severe eyelid spasms that render them functionally blind, socially reclusive, and unable to work or care for themselves. Oculoplastic surgeons frequently have to deal with patients with blepharospasm. The decrease in quality of life caused by this pathology drives all the attention to the resolution of the spasms. However, other conditions may be associated with them and must be kept in mind during the ophthalmological examination. Four patients with essential blepharospasm were diagnosed as glaucomatous during their follow-up at the Oculoplastic Service. All of them showed glaucomatous optic neuropathy and corresponding visual field defect and no clinically apparent secondary cause for their glaucoma. Forced eyelid closure may lead to intraocular pressure peaks. These patients with blepharospasm present repetitive and spasmodic eyelid contractions and the intraocular pressure rise observed during eyelid squeezing could be an additional risk factor for glaucomatous damage. Our case series suggest that patients with blepharospasm should be seriously evaluated for glaucoma.Blefaroespasmo essencial é uma distonia facial caracterizada por contrações espontâneas, espasmódicas e involuntárias dos músculos palpebrais, podendo tornar os pacientes funcionalmente cegos. Tais pacientes são geralmente referidos aos médicos oculoplásticos para avaliação e tratamento. Devido à intensidade dos espasmos e ao comprometimento da qualidade de vida, toda a atenção é dirigida à sua resolução e outras condições oculares associadas podem passar despercebidas. Neste estudo, quatro pacientes com blefaroespasmo foram diagnosticados como glaucomatosos durante o seu seguimento no Departamento de Plástica Ocular. As quatro pacientes apresentavam neuropatia óptica glaucomatosa e defeito no campo visual compatível, sem que houvesse nenhuma causa secundária para o glaucoma. O fechamento palpebral forçado causa importante aumento da pressão intra-ocular e estes pacientes com blefaroespasmo, por apresentar contrações espasmódicas e repetitivas das pálpebras, poderiam estar sob risco aumentado de desenvolver glaucoma

PPPs e decisões de investimento na construção de estádios de futebol

O presente artigo objetiva discutir os limites e as possibilidades da utilização de Parcerias Público-Privadas (PPPs) para construção de estádios de futebol. Para tanto, primeiramente, discute-se as PPPs e seus riscos. A presença de riscos associados às PPPs suscita a incorporação da teoria de opções reais – instrumental capaz de lidar com situações de incerteza quando da análise de investimentos. Tendo como pano de fundo as discussões em torno da candidatura da cidade de Salvador como sede à Copa do Mundo de Futebol de 2014 no Brasil, realizamos um exercício que ilustra as condições em que as PPPs são adequadas para a viabilização de uma nova arena esportiva apta a atender os padrões estipulados pela FIFA. Para operacionalizar o problema, estabelecemos uma metodologia de cálculo para o prêmio de um seguro a ser contratado para situações de baixa demanda. Ao final do artigo conclui-se que, em função das incertezas de demanda associadas à bilheteria de jogos de futebol, em parte condicionadas ao desempenho esportivo dos mandantes dos jogos, empreendimentos no entorno do estádio são essenciais para mitigar os riscos e, por conseqüência, viabilizar as PPPs

Evidence for Strong and Weak Phenyl-C61-Butyric Acid Methyl Ester Photodimer Populations in Organic Solar Cells

In polymer/fullerene organic solar cells, the photochemical dimerization of phenyl-C61-butyric acid methyl ester (PCBM) was reported to have either a beneficial or a detrimental effect on device performance and stability. In this work, we investigate the behavior of such dimers by measuring the temperature dependence of the kinetics of PCBM de-dimerization as a function of prior light intensity and duration. Our data reveal the presence of both “weakly” and “strongly” bound dimers, with higher light intensities preferentially generating the latter. DFT simulations corroborate our experimental findings and suggest a distribution of dimer binding energies, correlated with the orientation of the fullerene tail with respect to the dimer bonds on the cage. These results provide a framework to rationalize the double-edged effects of PCBM dimerization on the stability of organic solar cells