A statistical study of large field-aligned flows of thermal ions at high-latitudes

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.

Are real options a real option for real-world finance professionals? case study : the application of real options to evaluate investment projects in the latin american oil and gas field services industry

Brasil e outros mercados emergentes continuarão a apresentar muitas oportunidades de investimento nos próximos anos. Profissionais financeiros que gerenciam os processos de orçamento de capital nas empresas terão grandes desafios a enfrentar. Características específicas destes projetos como preços ligados a commodities (por exemplo: petróleo e gás e projetos agrícolas) e as incertezas habituais relacionadas com os mercados emergentes são desafios adicionais. Neste cenário, ferramentas mais sofisticadas de orçamento de capital como Opções Reais, oferece uma teoria mais robusta para lidar com incerteza, flexibilidade gerencial, e os resultados voláteis embutidas nestas oportunidades. A teoria de Opções Reais assume que o envolvimento dos gestores nos projetos gera valor à medida que potencializam os bons resultados ou reduzem as perdas por abandonar projetos com maus resultados. O objetivo principal desta pesquisa foi aplicar a análise de Opções Reais para um projeto de investimento e discutir o processo e os resultados da metodologia. O estudo de caso analisa retroativamente um projeto de investimento na Colômbia e compara os resultados sob o tradicional VPL e Opções Reais. As técnicas de avaliação foram realizadas como se estivessem sendo aplicadas no momento em que o projeto foi aprovado, e depois comparadas com o desempenho real do projeto. O estudo de caso avaliado possui dois tipos de Opções Reais: primeiro, o efeito de uma opção para cancelar um contrato que é analisado a partir da perspectiva do cliente que pode exercer essa opção, e o segundo, a opção de abandonar e adiar a partir da perspectiva da empresa que irá executar a investimento.

International civil society actors in Genetically Modificied Organisms as a field of struggle: a neo-gramscian study in Brazil and the United Kingdom

Since the international financial and food crisis that started in 2008, strong emphasis has been made on the importance of Genetically Modified Organisms (GMOs) (or “transgenics”) under the claim that they could contribute to increase food productivity at a global level, as the world population is predicted to reach 9.1 billion in the year 2050 and food demand is predicted to increase by as much as 50% by 2030. GMOs are now at the forefront of the debates and struggles of different actors. Within civil society actors, it is possible to observe multiple, and sometime, conflicting roles. The role of international social movements and international NGOs in the GMO field of struggle is increasingly relevant. However, while many of these international civil society actors oppose this type of technological developments (alleging, for instance, environmental, health and even social harms), others have been reportedly cooperating with multinational corporations, retailers, and the biotechnology industry to promote GMOs. In this thesis research, I focus on analysing the role of “international civil society” in the GMO field of struggle by asking: “what are the organizing strategies of international civil society actors, such as NGOs and social movements, in GMO governance as a field of struggle?” To do so, I adopt a neo-Gramscian discourse approach based on the studies of Laclau and Mouffe. This theoretical approach affirms that in a particular hegemonic regime there are contingent alliances and forces that overpass the spheres of the state and the economy, while civil society actors can be seen as a “glue” to the way hegemony functions. Civil society is then the site where hegemony is consented, reproduced, sustained, channelled, but also where counter-hegemonic and emancipatory forces can emerge. Considering the importance of civil society actors in the construction of hegemony, I also discuss some important theories around them. The research combines, on the one hand, 36 in-depth interviews with a range of key civil society actors and scientists representing the GMO field of struggle in Brazil (19) and the UK (17), and, on the other hand, direct observations of two events: Rio+20 in Rio de Janeiro in 2012, and the first March Against Monsanto in London in 2013. A brief overview of the GMO field of struggle, from its beginning and especially focusing in the 1990s when the process of hegemonic formation became clearer, serves as the basis to map who are the main actors in this field, how resource mobilization works, how political opportunities (“historical contingencies”) are discovered and exploited, which are the main discourses (“science” and “sustainability” - articulated by “biodiversity preservation”, “food security” and “ecological agriculture”) articulated among the actors to construct a collective identity in order to attract new potential allies around “GMOs” (“nodal point”), and which are the institutions and international regulations within these processes that enable hegemony to emerge in meaningful and durable hegemonic links. This mapping indicates that that the main strategies applied by the international civil society actors are influenced by two central historical contingencies in the GMO field of struggle: 1) First Multi-stakeholder Historical Contingency; and 2) “Supposed” Hegemony Stability. These two types of historical contingency in the GMO field of struggle encompass deeper hegemonic articulations and, because of that, they induce international civil society actors to rethink the way they articulate and position themselves within the field. Therefore, depending on one of those moments, they will apply one specific strategy of discourse articulation, such as: introducing a new discourse in hegemony articulation to capture the attention of the public and of institutions; endorsing new plural demands; increasing collective visibility; facilitating material articulations; sharing a common enemy identity; or spreading new ideological elements among the actors in the field of struggle.

3-D reconstruction by extended depth-of-field in failure analysis - Case study II: Fractal analysis of interlaminar fracture in carbon/epoxy composites

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

3-D reconstruction by extended depth-of-field in failure analysis - Case study I: Qualitative fractographic investigation of fractured bolts in a partial valve

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A laboratory study of the transfer of U-234 and U-238 during water-rock interactions in the Carnmenellis granite (Cornwall, England) and implications for the interpretation of field data

Laboratory time-scale experiments were conducted on gravels from the Carnmenellis granite, Cornwall, England, with the purpose of evaluating the release of natural uranium isotopes to the water phase. The implications of these results for the production of enhanced U-234/U-238 activity ratios in Cornish groundwaters are discussed. It is suggested that the U-234/U-238 lab data can be used to interpret activity ratios from Cornwall, even when the observed inverse relationship between dissolved U and U-234/U-238 in leachates/etchates is taken into account. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Field methods for the study of ants in sugarcane plantations in Southeastern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Two-wavelength whole-field interferometry setup for thermal lens study

In this paper we present a new approach for thermal lens analysis using a two-wavelength DSPI (Digital Speckle Pattern Interferometry) setup for wavefront sensing. The employed geometry enables the sensor to detect wavefronts with small phase differences and inherent aberrations found in induced lenses. The wavefronts was reconstructed by four-stepping fringe evaluation and branch-cut unwrapping from fringes formed onto a diffusive glass. Real-time single-exposure contour interferograms could be obtained in order to get discernible and low-spacial frequency contour fringes and obtain low-noise measurements. In our experiments we studied the thermal lens effect in a 4% Er-doped CaO-Al2O3 glass sample. The diode lasers were tuned to have a contour interval of around 120 μm. The incident pump power was longitudinally and collinearly oriented with the probe beams. Each interferogram described a spherical-like wavefront. Using the ABCD matrix formalism we obtained the induced lens dioptric power from the thermal effect for different values of absorbed pump power. © 2012 Copyright SPIE.

Comparison of the ant assemblages in three phytophysionomies: Rocky field, secondary forest, and riparian forest - A case study in the state park of Ibitipoca, Brazil

Ant assemblages are almost all related with the vegetation composition and so can provide us important information for conservation strategies, which are especially relevant to an environmentally protected area. We sampled the ant fauna in three different phytophysionomies in order to verify if the composition of ant species is different among the areas, especially because one of the areas is a Rocky Field and there is little information about the ant fauna in this habitat. A total of 8730 individuals were registered and an NMDS analysis showed that the ant assemblies are different at the three phytophysionomies (Rocky Field, Riparian Forest, and Secondary Forest). This study shows that the species that compose the ant assemblies in different phytophysionomies are a reflex of the environment, supporting the hypothesis that the vegetational composition results in different compositions in the ant assembly. Vegetal composition is determinant in the formation of the litter and consequently in the occurrence of ant species that depend on this layer of organic matter for nesting and foraging. © 2012 Juliane Floriano Santos Lopes et al.

The perception of brazilian researchers concerning the factors that influence the citation of their articles: A study in the field of sustainability

With growing institutional pressure from the Brazilian government to increase the impact of research that it funds, Brazilian researchers are increasingly interested in discovering factors that affect the citation of their articles. The aim of the present article was to assess the perceptions of Brazilian sustainability researchers to identify factors that influence the impacts of their research. A survey was conducted with researchers in the field of sustainability and 89 questionnaires were completed. All of those researchers have articles or research projects in the field of sustainability (mixing environmental, social and/or economical) recorded in the Scielo or Lattes Curriculum Brazilian databases. Results suggest four factors that may explain the impact of article citations: (1) prestige of the author and the research network; (2) prestige of the means of publication and indexing; (3) accessibility and quality characteristics of the article; and (4) international nature of communication and scope of the study. Surprisingly, such factors were not statistically significant in explaining the citations of the participating researchers. These results show the need to consider other factors that can explain the impact of research, discovering the missing links. © 2013 Elsevier Inc.

Study of pK Values and Effective Dielectric Constants of Ionizable Residues in Pentapeptides and in Staphylococcal Nuclease (SNase) Using a Mean-Field Approach

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Study of magnetic field enhanced plasma immersion ion implantation in Silicon

A comparison between experimental measurements and numerical calculations of the ion current distribution in plasma immersion ion implantation (PIII) with external magnetic field is presented. Later, Silicon samples were implanted with nitrogen ion to analyze the effect on them. The magnetic field considered is essentially non-uniform and is generated by two magnetic coils installed on vacuum chamber. The presence of both, electric and magnetic field in PIII create a crossed ExB field system, promoting drift velocity of the plasma around the target. The results found shows that magnetized electrons drifting in ExB field provide electron-neutral collision. The efficient ionization increases the plasma density around the target where a magnetic confinement is formed. As result, the ion current density increases, promoting significant changes in the samples surface properties, especially in the surface wettability.

H-1 low- and high-field NMR study of the effects of plasma treatment on the oil and water fractions in crude heavy oil

The chemical and physical properties of a Brazilian heavy oil submitted to plasma treatment were investigated by H-1 low-and high-field nuclear magnetic resonance (NMR) combined to the characterization of rheological properties, thermogravimetry and measurement of basic sediments and water (BSW) content. The crude oil was treated in a dielectric barrier discharge plasma reactor, using natural gas, CO2 or H-2 as working gas. The results indicated a large drop in the water content of the plasma-treated samples as compared to the crude oil, giving rise to a reduction in the viscosity. No significant chemical change was produced in the oil portion itself, as observed by H-1 NMR. The water contents determined by H-1 low-field NMR analyses agreed well with those obtained by BSW, indicating the low-field NMR methods as a useful tool for following the effects of plasma treatments on heavy oils, allowing the separation of the effects caused on the water and oil fractions. (C) 2011 Elsevier Ltd. All rights reserved.

Effect of electromagnetic field on bone regeneration around dental implants after immediate placement in the dog mandible: a pilot study

Background: Accelerating bone healing around dental implants can reduce the long-term period between the insertion of implants and functional rehabilitation. Objective: This in vivo study evaluated the effect of a constant electromagnetic field (CEF) on bone healing around dental implants in dogs. Materials and methods: Eight dental implants were placed immediately after extraction of the first premolar and molar teeth on the mandible of two male dogs and divided into experimental (CEF) and control groups. A CEF at magnetic intensity of 0.8 mT with a pulse width of 25 mu s and frequency of 1.5 MHz was applied on the implants for 20 min per day for 2 weeks. Result and conclusion: After qualitative histological analysis, a small quantity of newly formed bone was observed in the gap between the implant surface and alveolar bone in both groups.

Comparative study on the far-field spectra and near-field amplitudes for silver and gold nanocubes irradiated at 514, 633 and 785 nm as a function of the edge length

We describe a systematic investigation by the discrete dipole approximation on the optical properties of silver (Ag) and gold (Au) nanocubes as a function of the edge length in the 20-100 nm range. Our results showed that, as the nanocube size increased, the plasmon resonance modes shifted to higher wavelengths, the contribution from scattering to the extinction increased, and the quadrupole modes became more intense in the spectra. The electric field amplitudes at the surface of the nanocubes were calculated considering 514, 633 and 785 nm as the excitation wavelengths. While Ag nanocubes displayed the highest electric field amplitudes (vertical bar E vertical bar(max)) when excited at 514 nm, the Au nanocubes displayed higher vertical bar E vertical bar(max) values than Ag, for all sizes investigated, when the excitation wavelength was either 633 or 785 nm. The variations in vertical bar E vertical bar(max) as a function of size for both Ag and Au nanocubes could be explained based on the relative position of the surface plasmon resonance peak relative to the wavelength of the incoming electromagnetic wave. Our results show that not only size and composition, but also the excitation wavelength, can play an important role over the maximum near-field amplitudes values generated at the surface of the nanocubes.