Morphological properties of superclusters of galaxies

We studied superclusters of galaxies in a volume-limited sample extracted from the Sloan Digital Sky Survey Data Release 7 and from mock catalogues based on a semi-analytical model of galaxy evolution in the Millennium Simulation. A density field method was applied to a sample of galaxies brighter than M(r) = -21+5 log h(100) to identify superclusters, taking into account selection and boundary effects. In order to evaluate the influence of the threshold density, we have chosen two thresholds: the first maximizes the number of objects (D1) and the second constrains the maximum supercluster size to similar to 120 h(-1) Mpc (D2). We have performed a morphological analysis, using Minkowski Functionals, based on a parameter, which increases monotonically from filaments to pancakes. An anticorrelation was found between supercluster richness (and total luminosity or size) and the morphological parameter, indicating that filamentary structures tend to be richer, larger and more luminous than pancakes in both observed and mock catalogues. We have also used the mock samples to compare supercluster morphologies identified in position and velocity spaces, concluding that our morphological classification is not biased by the peculiar velocities. Monte Carlo simulations designed to investigate the reliability of our results with respect to random fluctuations show that these results are robust. Our analysis indicates that filaments and pancakes present different luminosity and size distributions.

Síntese enzimática de ésteres de açúcar: surfactantes e polímeros como novos materiais ambientalmente seguros

Sugar esters are substances which possess surfactant, antifungical and bactericidal actions and can be obtained through two renewable sources of raw materials: sugars and vegetable oils. Their excellent biodegradability, allied to lhe fact that they are non toxic, insipid, inodorous, biocompatible, no-ionic, digestible and because they can resist to adverse conditions of temperature, pH and salinity, explain lhe crescent use of these substances in several sections of lhe industry. The objective of this thesis was to synthesize and characterize surfactants and polymers containing sugar branched in their structures, through enzymatic transesterification of vinyl esters and sugars, using alkaline protease from Bacillus subtilis as catalyst, in organic medium (DMF).Three types of sugars were used: L-arabinose, D-glucose and sucrose and two types of vinyl esters: vinyl laurate and vinyl adipate. Aiming to reach high conversions from substrates to products for a possible future large scale industrial production, a serie of variables was optimized, through Design of Experiments (DOE), using Response Surface Methodology (RSM).The investigated variables were: (1) enzyme concentration; (2) molar reason of substrates; (3) water/solvent rale; (4) temperature and (5) time. We obtained six distinct sugar esters: 5-0-lauroyl L-arabinose, 6-0-lauroyl D-glucose, 1'-O-lauroyl sucrose, 5-0-vinyladipoyl L-arabinose, 6-0-vinyladipoyl D-glucose and 1 '-O-vinyladipoyl sucrose, being lhe last three polymerizable. The progress of lhe reaction was monitored by HPLC analysis, through lhe decrease of sugar concentration in comparison to lhe blank. Qualitative analysis by TLC confirmed lhe formation of lhe products. In lhe purification step, two methodologies were adopted: (1) chromatographic column and (2) extraction with hot acetone. The acylation position and lhe chemical structure were determined by 13C-RMN. The polymerization of lhe three vinyl sugar esters was possible, through chemical catalysis, using H2O2 and K2S2O8 as initiators, at 60°C, for 24 hours. IR spectra of lhe monomers and respective polymers were compared revealing lhe disappearance of lhe vinyl group in lhe polymer spectra. The molar weights of lhe polymers were determined by GPC and presented lhe following results: poly (5-0-vinyladipoyl L-arabinose): Mw = 7.2 X 104; PD = 2.48; poly (6-0-vinyladipoyl D-glucose): Mw = 2.7 X 103; PD = 1.75 and poly (1'-O-vinyladipoyl sucrose): Mw = 4.2 X 104; PD = 6.57. The six sugar esters were submitted to superficial tension tests for determination of the critical micelle concentrations (CMC), which varied from 122 to 167 ppm. Finally, a study of applicability of these sugar esters, as lubricants for completion fluids of petroleum wells was' accomplished through comparative analysis of lhe efficiency of these sugar esters, in relation to three commercial lubricants. The products synthesized in this thesis presented equivalent or superior action to lhe tested commercial products

Assessment of cumulative damage by using ultrasonic C-scan on carbon fiber/epoxy composites under thermal cycling

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

Structure formation in the presence of dark energy perturbations

We study non-linear structure formation in the presence of dark energy. The influence of dark energy on the growth of large-scale cosmological structures is exerted both through its background effect on the expansion rate, and through its perturbations. In order to compute the rate of formation of massive objects we employ the spherical collapse formalism, which we generalize to include fluids with pressure. We show that the resulting non-linear evolution equations are identical to the ones obtained in the pseudo-Newtonian approach to cosmological perturbations, in the regime where an equation of state serves to describe both the background pressure relative to density, and the pressure perturbations relative to the density perturbations. We then consider a wide range of constant and time-dependent equations of state (including phantom models) parametrized in a standard way, and study their impact on the non-linear growth of structure. The main effect is the formation of dark energy structure associated with the dark matter halo: non-phantom equations of state induce the formation of a dark energy halo, damping the growth of structures; phantom models, on the other hand, generate dark energy voids, enhancing structure growth. Finally, we employ the Press-Schechter formalism to compute how dark energy affects the number of massive objects as a function of redshift (number counts).

On the unzipping of multiwalled carbon nanotubes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Tabu search algorithm for network synthesis

Large scale combinatorial problems such as the network expansion problem present an amazingly high number of alternative configurations with practically the same investment, but with substantially different structures (configurations obtained with different sets of circuit/transformer additions). The proposed parallel tabu search algorithm has shown to be effective in exploring this type of optimization landscape. The algorithm is a third generation tabu search procedure with several advanced features. This is the most comprehensive combinatorial optimization technique available for treating difficult problems such as the transmission expansion planning. The method includes features of a variety of other approaches such as heuristic search, simulated annealing and genetic algorithms. In all test cases studied there are new generation, load sites which can be connected to an existing main network: such connections may require more than one line, transformer addition, which makes the problem harder in the sense that more combinations have to be considered.

Reproductive technology in domestic carnivorous

Background: The delay in development of artificial reproduction techniques on carnivorous could be due to countless reasons, but the lack of commercial interest is probably the most important one. The majority of canines are small structures, canidae are extremely fertile and a great number of species are adapted to domestication or captivity. Finally, the canine gamete physiology presents a difficult adaptation of technology knowledge obtained from other species. Furthermore, domestic felines are animals of company and there is no interest in reproducing them in a large scale, as it has been observed in other domestic animals, however, besides of being a valuable model for the development of in vitro techniques, the domestic cat is also used as an embryo receptor for different species of small wild felines due to physiological similarities among them, in vitro embrionary development, Review: It was reviewed the main insights about the reproductive physiology in female dogs, in vitro oocytary maturation (IVM), pregnancy and conception rate with dogs' frozen/unfrozen semen and PIV in domestic cats. The majority of mammal oocytes restart meiosis spontaneously after ovulation and reaches MII in artificial environment; in an in vitro maturation system in bovines, around 90% of oocytes complete their maturation, although its development capacity can be reduced subsequently. The success of IVM in canidae have been limited, with maturation rate varying from 0 to 58%, usually around 20%. The greatest difficulties include oocyte quality, hormonal environment, protein supplementation, cumulus / oocyte cell interaction, donor breed and age, culture systems, oxygen tension, amino acids, growth factor and sequential means. The freezing process reduces the quality of the semen, firstly because it reduces the number of living sperms and secondly because freezing produces cell modifications that could alter the sperm motility, longevity, integrity of membranes and its fertilizing capacity. Conclusion: Nowadays, several researches are being performed with the aim of increasing viability after dogs' and cats' semen is unfrozen, using extenders, cryoprotectors, freezing and unfreezing curves, addition of antioxidant substances. The aim of this text is to inform about the improvements obtained on the artificial reproduction techniques, emphasizing the oocytary maturation in female dogs, semen cryopreservation and artificial insemination in domestic dogs and cats.

Small-scale mining: a new entrepreneurial approach

Includes bibliography

Local and regional features of surface radiation fluxes over the tropical Atlantic ocean near Sao Pedro and Sao Paulo archipelago: Evidence of small scale upwelling

To properly describe the interactions between the ocean and atmosphere, it is necessary to assess a variety of time and spatial scales phenomena. Here, high resolution oceanographic and meteorological data collected during an observational campaign carried out aboard a ship in the tropical Atlantic Ocean, on May 15-24, 2002, is used to describe the radiation balance at the ocean interface. Data collected by two PIRATA buoys, along the equator at 23°W and 35°W and satellite and climate data are compared with the data obtained during the observational campaign. Comparison indicates remarkable similarity for daily and hourly values of radiation fluxes components as consequence of the temporal and spatial consistence presented by the air and water temperatures measured in situ and estimated from large scale information. The discrepancy, mainly in the Sao Pedro and Sao Paulo Archipelago area, seems to be associated to the local upwelling of cold water, which is not detected in all other estimates investigated here. More in situ data are necessary to clarify whether this upwelling flow has a larger scale effect and what are the meteorological and oceanographic implications of the local upwelling area on the tropical waters at the Brazilian coast.

On the unzipping mechanisms of carbon nanotubes: Insights from reactive molecular dynamics simulations

Unzipping carbon nanotubes (CNTs) is considered one of the most promising approaches for the controlled and large-scale production of graphene nanoribbons (GNR). These structures are considered of great importance for the development of nanoelectronics because of its dimensions and intrinsic nonzero band gap value. Despite many years of investigations some details on the dynamics of the CNT fracture/unzipping processes remain unclear. In this work we have investigated some of these process through molecular dynamics simulations using reactive force fields (ReaxFF), as implemented in the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) code. We considered multi-walled CNTs of different dimensions and chiralities and under induced mechanical stretching. Our preliminary results show that the unzipping mechanisms are highly dependent on CNT chirality. Well-defined and distinct fracture patterns were observed for the different chiralities. Armchair CNTs favor the creation of GNRs with well-defined armchair edges, while zigzag and chiral ones produce GNRs with less defined and defective edges. © 2012 Materials Research Society.

Argentina: Dissemination of genetically modified cotton and its impact on the profitability of small-scale farmers in the Chaco province

Includes bibliography

Controlled route to the fabrication of carbon and boron nitride nanoscrolls: A molecular dynamics investigation

Carbon nanoscrolls (graphene layers rolled up into papyrus-like tubular structures) are nanostructures with unique and interesting characteristics that could be exploited to build several new nanodevices. However, an efficient and controlled synthesis of these structures was not achieved yet, making its large scale production a challenge to materials scientists. Also, the formation process and detailed mechanisms that occur during its synthesis are not completely known. In this work, using fully atomistic molecular dynamics simulations, we discuss a possible route to nanoscrolls made from graphene layers deposited over silicon oxide substrates containing chambers/pits. The scrolling mechanism is triggered by carbon nanotubes deposited on the layers. The process is completely general and can be used to produce scrolls from other lamellar materials, like boron nitride, for instance. © 2013 American Institute of Physics.

The Netherlands Antilles: trade and integration with CARICOM

Introduction The Netherlands Antilles is an autonomous entity within the Kingdom of the Netherlands and comprises a federation of five Caribbean islands: Bonaire and Curacao (the Leeward islands) which comprise 80 per cent of the population of 211,000 and Saba, St. Eustatius and the southern part of St. Maarten (the Windward islands). Like the other countries in the Kingdom, it enjoys full autonomy in internal matters as, for example, education, public health, justice and customs. It has a per capita income of about US$ 12,000. The Leeward Islands and the Windward Islands account for about 75 per cent (Curacao (70 per cent) and Bonaire (5 per cent)) and 25 percent respectively of the economy of the Netherlands Antilles. The Netherlands Antilles has its own currency, the Netherlands guilder, which is pegged to the United States dollar at a fixed rate since 1971. The economy has some unique features that stem from its close relations with the Netherlands, its undiversified nature and heavy dependence on tourism, offshore finance, oil refining and shipping, the high share of trade (exports of goods and services of about 75 per cent of GDP), its geographical characteristics, its common border with the French Republic on St. Maarten, its duty-free access for imports from Aruba, its de facto free trade zone (FTZ), partial dollarization, especially for the Windward Islands, and its highly regulated labor market (1). Adverse economic shocks in the last two decades affected particularly the offshore financial sector and the oil refinery and, to a lesser extent, tourism. The repeal of withholding taxes in the United States in the 1980s indirectly caused the collapse of a number of highly profitable offshore financial activities in Curacao, leading to significant drops in government revenue and contributions to foreign exchange earnings. The withdrawal of Shell from Curacao in 1986 and the (temporary) closure of the oil refinery which had been a mainstay of the Curacao economy for almost three quarters of a century was the second major shock. It was subsequently leased to the Venezuelan State Company, Petroleos de Venezuela Sociedad Anonima (PDVSA), which resumed operations and preserved employment. In the 1990s, the Windward Islands were bit by several devastating hurricanes, which destroyed much of the economic infrastructure on the islands, including about half of the number of available hotel rooms in St Maarten. Further negative shocks were related to the discontinuation of certain trade privileges on European markets for Overseas Countries and Territories (OCTs), the withdrawal by the Netherlands of certain tax privileges for Dutch pensioners residing in the Netherlands Antilles and disruptions in the availability of Solidarity Fund resources for the smaller islands. National income has been on the decline since 1997. GDP declined by about 6 per cent between 1997 and 1999. Underlying fiscal imbalances and structural weaknesses have also impacted negatively on the economy. In recent years, with recession high unemployment and migration have been experienced (2). The Netherlands Antilles has been able to survive thanks to additional aid from the Netherlands, large-scale spontaneous emigration (mostly to the Netherlands), some drop in international reserves, an increase in domestic debt and arrears and reduced outlays for the maintenance of public assets. From 1986 onwards, successive efforts at restoring macroeconomic balance, particularly with regard to public finance, were made, but were unsuccessful. Adjustment was also attempted in 1996 and 1997, but failed to meet the desired targets. In 1999, the government launched a new National Recovery Plan" (NRP). The NRP contains important medium-term structural adjustment measures aimed at restoring macroeconomic balance and conditions for revitalizing the economy. The NRP subsequently served as an important input into a comprehensive adjustment plan drawn up with the assistance of the International Monetary Fund (IMF) and reflected in the government's Memorandum of Economic Policies dated 15 September 2000. Beyond restoring macroeconomic balance and reforming the economic incentive framework, the government aims at establishing a Comprehensive Development Framework (CDF) for the formulation and implementation of a sustainable long-term growth strategy. It is against the above background that this study is undertaken. Its main objective is to assess the integration options facing the Netherlands Antilles (3) vis-a-vis the Caribbean Community (CARICOM). A secondary objective is to examine the above taking into account, inter alia, the level of trade between the Netherlands Antilles and CARICOM, the barriers to trade between the two groups of countries and the requirements for increasing trade between the two groups of countries. The Consultant was given an initial Draft Terms of Reference (Annex 1) with the intention of modifying it in the course of the interviews with all the stakeholders. The main idea that emerged from these interviews was a concern with some possible form of association with CARICOM. The Consultant was asked to exam the costs and benefits of various forms of association and to recommend an option. This adjustment of the Terms of Reference (TOR) was substantial and involved the Consultant having to do some interviews and collect documentation in CARICOM. The study essentially revolves around the search for a road map for the Netherlands Antilles. It is tackled in the first instance by describing the existing system of trade of the Netherlands Antilles with a view to determining the import and export structures and the specific nature and extent of trade in goods and services between the Netherlands Antilles and CARICOM. 1 Netherlands Antilles: Elements of a Strategy for Economic Recovery and Sustainable Growth. Interim Report of the World Bank Mission, 5-20 December 2000. 2 IMF, IMF Country Report No. 01/73 Kingdom of the Netherlands-Netherlands Antilles-Recent Development, Selected Issues and Statistical Appendix. May 2001 3 The Netherlands Antilles is a country within the Kingdom of the Netherlands. It contains five islands. Curacao and Bonaire (Leewards) and St Eustatius, Saba and St Maarten (The Windwards)"

Influência de ciclos térmicos na microestrutura e propriedades mecânicas da junta soldada do aço COS CIVIL 300

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência do processamento térmico sobre as propriedades mecânicas e microestruturais de um aço XC48 aplicado a componentes automotivos visando atendimento ao projeto ULSAB

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)