984 resultados para Catastrophic Rupture


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O mercado de capitais brasileiro não é representativo do tamanho de sua economia. Nos últimos anos, o crescimento observado nas áreas de serviços, indústria, agronegócio, e outras, não foi acompanhado pelo mercado financeiro. A estrutura verticalizada e o posicionamento monopolista da BM&F Bovespa, única bolsa de valores em atuação no mercado local, vão de encontro ao cenário encontrado em mercados internacionais. O advento da eletronificação e a atuação dos agentes reguladores proporcionaram que os mercados internacionais operassem em ambientes com múltiplas bolsas, incentivando a competitividade e trazendo benefícios para o investidor final, como redução de custos explícitos e implícitos, melhoria dos serviços prestados, diversidade de produtos, etc. Artigos recentes comprovam o benefício da fragmentação de ordens, e podem ser usados como referência no incentivo à quebra do monopólio que existe hoje no mercado brasileiro.

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MOREIRA, Luciana Moreira; SILVA, Armando Malheiro da. Impacto das tecnologias digitais nas bibliotecas universitarias: reflexões sobre o tema. Informaçao e sociedade: estudos. Joao Pessoa, v.19, n.3, p. 125-132,2009.

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The ceramics industry in Piauí is nowadays with 55 industries where 11 are in Teresina which is the mainstream of the state, producing 55 million shingles; in which 10 % is of this production is wasted being sometimes thrown on the margins of rivers, roads and highways provoking an environmental degradation. The main goal of this work is to verify the potential of producing semi porous ceramic using grog of shingles, on the first part of this work bodies-of-proof were produced from a basic formula of an industry, doping it with 5 %, 10 %, 15 % and 20 % in mass and in the second part of this work some bodies-of-proof were produced from a formula where one raw material was substituted by 50 % of grog and another substituting it all by grog, bodies-of-proof made of a basic formula previously announced was used for experiment control.The grog and the raw materials were characterized by: particle size analysis , thermal differential analysis, X ray diffraction , X ray fluorescence, an thermal gravimetric analysis and rational analyses. The bodies-of-proof were sintetisized in an industrial oven obeying the normal cycle adopted by an industry, with peak temperatures of 1135 oC and a fast burning cycle of 25 minutes having as energetic fuel liquefied petroleum gas . The pieces that were obtained by this were submersed in rehearsed physics of: water absorption of, apparent specific mass, apparent porosity, lineal retraction, rupture tension to the flexural and dilatometry; mineralogical analysis for X ray diffraction; and microstructural for electronic microscope of sweeping. For all the formulas with addition of grog, superior priorities to the requested by the requirements for semi porous and for the formula to F2-2,5 superior priorities to standard formulas which justifies the incorporation of the shingles in mass for the semi porous ceramic

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Pipelines for the transport of crude oil from the production wells to the collecting stations are named production lines . These pipes are subjected to chemical and electrochemical corrosion according to the environment and the type of petroleum transported. Some of these lines, depending upon the composition of the fluid produced, may leak within less than one year of operation due to internal corrosion. This work aims at the development of composite pipes with an external protecting layer of high density polyurethane for use in production lines of onshore oil wells, meeting operational requirements. The pipes were manufactured using glass fibers, epoxy resin, polyester resin, quartz sand and high density polyurethane. The pipes were produced by filament winding with the deposition of high density polyurethane on the external surface and threaded ends (API 15 HR/PM-VII). Three types of pipes were manufactured: glass/epoxy, glass/epoxy with an external polyurethane layer and glass/epoxy with an intermediate layer of glass fiber, polyester, sand and with an external polyurethane layer. The three samples were characterized by Scanning Electronic Microscopy (SEM) and for the determination of constituent content. In addition, the following tests were conducted: hydrostatic test, instant rupture, shorttime failure pressure, Gardner impact, transverse stiffness and axial tension. Field tests were conducted in Mossoró RN (BRAZIL), where 1,677 meters of piping were used. The tests results of the three types of pipes were compared in two events: after two months from manufacturing of the samples and after nine months of field application. The results indicate that the glass/epoxy pipes with an intermediate layer of fiber glass composite, polyester e sand and with an external layer of high density polyurethane showed superior properties as compared to the other two and met the requirements of pressure class, axial tensile strength, transverse stiffness, impact and environmental conditions, for onshore applications as production lines

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Metal-ceramic interfaces are present in tricone drill bits with hard ceramic inserts for oil well drilling operations. The combination of actions of cutting, crushing and breaking up of rocks results in the degradation of tricone drill bits by wear, total or partial rupture of the drill bit body or the ceramic inserts, thermal shock and corrosion. Also the improper pressfitting of the ceramic inserts on the bit body may cause its total detachment, and promote serious damages to the drill bit. The improvement on the production process of metal-ceramic interfaces can eliminate or minimize some of above-mentioned failures presented in tricone drill bits, optimizing their lifetime and so reducing drilling metric cost. Brazing is a widely established technique to join metal-ceramic materials, and may be an excellent alternative to the common mechanical press fitting process of hard ceramic inserts on the steel bit body for tricone drill bit. Wetting phenomena plays an essential role in the production of metal/ceramic interfaces when a liquid phase is present in the process. In this work, 72Silver-28Copper eutectic based brazing alloys were melted onto zirconia, silicon nitride and tungsten carbide/Co substrates under high vacuum. Contact angle evolution was measured and graphically plotted, and the interfaces produced were analysed by SEM-EDX. The AgCu eutectic alloy did not wet any ceramic substrates, showing high contact angles, and so without chemical interaction between the materials. Better results were found for the systemns containing 3%wt of titanium in the AgCu alloy. The presence os titanium as a solute in the alloy produces wettable cand termodinamically stable compounds, increasing the ceramics wetting beahviour

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The production of waste from urban and industrial activities is one of the factors of environmental contamination and has aroused attention of the scientific community, in the sense of its reuse. On the other hand, the city of Salvador/Ba, with approximately 262 channels, responsible for storm water runoff, produces every year, by the intervention of cleaning and clearing channels, a significant volume of sediments (dredged mud), and thus an appropriate methodology for their final destination. This study aims to assess the influence of incorporation of these tailings in arrays of clay for production of interlocked block ceramic, also known as ceramic paver. All the raw materials from the metropolitan region of Salvador (RMS) were characterized by x-ray fluorescence, x-ray diffraction, thermal analysis (TG and TDA), particle size analysis and dilatometry. With the use of statistical experimental planning technique, ternary diagram was defined in the study region and the analyzed formulations. The specimens were prepared with dimensions of 60x20x5mm³, by uniaxial pressing of 30 MPa and after sintering at temperatures of 900°, 1000º and 1100ºC the technological properties were evaluated: linear shrinkage, water absorption, apparent porosity, apparent specifies mass, flexural rupture and module. For the uniaxial compression strength used cylindrical probe body with Ø 50 mm. The standard mass (MP) was prepared with 90% by weight of clay and 10% by weight of Channel sediment (SCP), not being verified significant variations in the properties of the final product. With the incorporation of 10% by weight of manganese residue (PFM) and 10% by weight of the Ceramic waste (RCB) in the mass default, in addition to adjusting the plasticity due to less waste clay content, provided increased linear firing shrinkage, due the significant concentration of K2O, forming liquid phase at low temperature, contributing to decreased porosity and mechanical resistance, being 92,5 MPa maximum compressive strength verified. After extract test leachate and soluble, the piece containing 10% of the PFM, was classified as non-hazardous and inert material according to NBR10004/04 ABNT. The results showed the feasibility on using waste, SCP, RCB and PFM clay mass, at temperatures above 900ºC, paver ceramic production, according to the specifications of the technical standards, so that to exceed the 10% of the PFM, it becomes imperative to conduct studies of environmental impacts

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Metal-Ceramic (M/C) Zirconia-stainless steel interfaces have been processed through brazing techniques due to the excellent combination of properties such as high temperature stability, high corrosion resistance and good mechanical properties. However, some M/C interfaces show some defects, like porosity and cracks results in the degradation of the interfaces, leading even to its total rupture. Most of time, those defects are associated with an improper brazing parameters selection to the M/C system. In this work, ZrO2 Y-TZP and ZrO2 Mg - PSZ were joint with the stainless steel grade 304 by brazing using a eutectic silver-copper (Ag28Cu) interlayer alloy with different thermal cycles. Ceramic surfaces were previous mechanically metallized with titanium to improve adhesion of the system. The effect of temperature on the M/C interface was studied. SEM-EDS and 3 point flexural bend test were performed to evaluate morphology, chemical composition and mechanical resistance of the M/C interfaces. Lower thermal cycle temperatures produced better results of mechanical resistance, and more regular/ homogeneous reaction layers between braze alloy and metal-ceramic surfaces. Also was proved the AgCu braze alloy activation in situ by titanium

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Produced water is the main effluent linked to the activity of extraction of oil and their caring management is necessary due to the large volume involved, to ensure to minimize the negative impacts of discharges of these waters in the environment. This study aimed to analyze the use of retorted shale, which is a reject from the pyrolysis of pirobituminous shale, as adsorbent for the removal of phenols in produced water. The material was characterized by different techniques (grain sized analysis, thermal analysis, BET, FRX, FT-IR, XRD and SEM), showing the heterogeneity in their composition, showing its potential for the removal of varied compounds, as well as the phenols and their derivatives. For the analysis of the efficiency of the oil shale for the adsorption process, assays of adsorption balance were carried through, and also kinetic studies and dynamics adsorption, in the ETE of the UTPF of Petrobras, in Guamaré-RN. The balance assays shown a bigger conformity with the model of Langmuir and the kinetic model more adjusted to describe the adsorption of phenols in retorted shale was of pseudo-second order. The retorted shale presented a low capacity of adsorption of phenols (1,3mg/g), when related to others conventional adsorbents, however it is enough to the removal of these composites in concentrations presented in the produced water of the UTPF of Guamaré. The assays of dynamics adsorption in field had shown that the concentration of phenol in the effluent was null until reaching its rupture (58 hours). The results showed the possibility of use of the reject for removal of phenols in the final operations of the treatment process, removing as well, satisfactorily, the color and turbidity of the produced water, with more than 90% of removal

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Although there are a wide variety of additives that act in fresh state, to adjust the properties of cement, there is also a search by additions that improve the tenacity of the cement in the hardened state. This, in turn, can often be increased by inserting fibers, which act on the deflection of microcracks. This study aimed to use a microfiber glass wool (silica-based) as an additive reinforcing the cement matrix, improving the rupture tenacity, in order to prevent the propagation of microcracks in the cement sheath commonly found in oil wells submitted to high temperatures. The fibers were added at different concentrations, 2 to 5% (BWOC) and varied average sizes, grinding for 90 s, 180 s, 300 s, 600 s. The cement slurries were made with a density of 1,90 g/ cm3 (15,6 lb/gal), using Portland cement CPP- Special Class as the hydraulic binder and 40% silica flour. The characterization of the fiber was made by scanning electron microscopy (SEM), particle size by sieving, X-ray fluorescence (XRF), X-ray diffraction (XRD) and thermogravimetry (TG / DTG). Were performed technological tests set by the API (American Petroleum Institute) by rheology, stability, free water, compressive strength, as well as testing rupture energy, elastic modulus and permeability. The characterization results showed good thermal stability of the microfiber glass wool for application in oil wells submitted to steam injection and, also, that from the particle size data, it was possible to suggest that microfibers milled up to 300 s, are ideal to act as reinforcement to the cement slurries. The rheological parameters, there was committal of plastic viscosity when larger lengths were inserted of microfiber (F90). The values obtained by free water and stability were presented according to API. The mechanical properties, the incorporation of microfiber to the cement slurries gave better rupture tenacity, as compared to reference cement slurries. The values of compressive strength, elastic modulus and permeability have been maintained with respect to the reference cement slurries. Thus, cement slurries reinforced with microfiber glass wool can ensure good application for cementing oil wells submitted to steam injection, which requires control of microcracks, due to the thermal gradients

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

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

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This doctoral thesis presents an analysis of the production of bicarbonates and related regional development in Brazil. It is widely believed that one of Brazil s vocations lies in the agro-energy sector. However, current national agro-energy policies, together with the experience of Petrobras (the national oil company) in rural settlements in the state of Rio Grande do Norte, show that Brazil has fallen short of effectively including the North and Northeast regions of the country, let alone small-scale rural producers (residing in rural settlements or not), in the development process and related benefits from the country s participation in the current world energy grid. The methodology entails secondary research related to the theme, such as books, official documents, websites and statistical databases from diverse sources, in addition to an analysis of statements from interviews of Petrobras representatives and other important scientific, institutional and labor union authorities, in relation to agro-energy issues and the socio-economic participation of family-based agriculture in this process. Principal findings show a correlation between agro-energy and regional development, creating the potential for numerous opportunities and challenges. Findings demonstrate the possibility of reversing/reducing historically rooted indices of hunger and poverty that continue to devastate the North and Northeast regions. At the same time, the thesis points to a potentially catastrophic increase in regional disparities, should the present historic moment not be seized upon so as to include these regions. Classic examples of non-policy at the federal level are presented as evidence of the absence of a regionally focused agroenergy policy in the current government, reinforced by the experiences of Petrobras in the Rio Grande do Norte rural settlements. Finally, the thesis concludes that there is an urgent need to create a government-sponsored enterprise (with a structure similar to Petrobras) with the purpose of implementing a truly broad and inclusive development process for the bicarbonates production sector, while remaining attentive to Brazil s opportune and critical role in the world s current agro-energy scenario.

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The debate around the thematic of Corporate Social Responsibility - CSR involves economic, social, cultural and symbolic aspects in the relations established between company and society. In Brazilian reality, the CSR, understood as enterprise actions, external and/or internal, that contributes to social and ambient improvement, gains greater visibility in 1990 decade. Although the significant increase of theoretical productions about CSR pertinent elements, it is still scarce the studies that treats about the relation company/society in the northeastern reality, and singularly, in Rio Grande do Norte. It was in this perspective, that, in being the salt industry one of most important in the potiguar economic history formation , the present work investigated practicies and perceptions of salt entrepreneurship about CSR. Considering all the Rio Grande do Norte salt industry history phases, since the period of the Brazil s settling, as well as the characteristics of the study object, was opted to the qualitative research, objectified in interviews half-structuralized realized with the salt segment entrepreneurs, as well as professionals of ambient management and human resources working in potiguar salt segment. The research main results indicated a coexistence between the mechanisms of management seated on personal and paternalists relations, typical of traditional salt industry, and the emergency of innovative elements typical of the modern management, like the CSR. In this context, a tension between continuity and rupture with the traditional mechanisms of management in salt entrepreneurship actions

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This study want to know how Josué de Castro, the two terms of a congressman, participated in the Brazilian political-ideological debate of the 1950s. For this, search the 61 speeches in the plenary of the House of Representatives and its 14 projects, analyzing them as historical documents that describe an experience, which enables the central category amalgamated the subject and his time, which breaks up the possibilities of new social practices. Unity of action and reflection, the experience of Castro in the Brazilian parliament has got on the basis of a previous flow experiences in the political-institutional and scientific. Together with the personal history, the political intellectual scenario of his time was another variable considered in the first chapter of this work. In the second chapter did an analysis of 32 speeches and projects of the first term of Josué de Castro, grouping them by thematic affinities. The 43 for the second term were discussed in the third chapter, leaving the final considerations answer the research objectives: What are the main interlocutors? What are your political positions? What are the points of rupture and continuity in his political career? Josué de Castro spoke to the Brazilian state directly to the president, some ministers and to the SUDENE, the ONU appears indirectly through the reports of his participations. His political position was a national-developmentalist who embraced the cause of self-determination of the countries, anti-imperialism, agrarian reform and regional planning, strongly inspired by Celso Furtado and San Tiago Dantas. Castro often has blended a liberal and Marxist terminology, relying on different ideologies to do support his fight against hunger