Implementação da rotina de unfolding para determinação de distribuição de tamanho de grãos esféricos via distribuição de interceptos lineares e de área de seção

Na unfolding method of linear intercept distributions and secction área distribution was implemented for structures with spherical grains. Although the unfolding routine depends on the grain shape, structures with spheroidal grains can also be treated by this routine. Grains of non-spheroidal shape can be treated only as approximation. A software was developed with two parts. The first part calculates the probability matrix. The second part uses this matrix and minimizes the chi-square. The results are presented with any number of size classes as required. The probability matrix was determined by means of the linear intercept and section area distributions created by computer simulation. Using curve fittings the probability matrix for spheres of any sizes could be determined. Two kinds of tests were carried out to prove the efficiency of the Technique. The theoretical tests represent ideal cases. The software was able to exactly find the proposed grain size distribution. In the second test, a structure was simulated in computer and images of its slices were used to produce the corresponding linear intercept the section area distributions. These distributions were then unfolded. This test simulates better reality. The results show deviations from the real size distribution. This deviations are caused by statistic fluctuation. The unfolding of the linear intercept distribution works perfectly, but the unfolding of section area distribution does not work due to a failure in the chi-square minimization. The minimization method uses a matrix inversion routine. The matrix generated by this procedure cannot be inverted. Other minimization method must be used

Estudo de revestimentos inorgânicos com inibidor de corrosão aplicado na superfície do concreto

The corrosive phenomenon on reinforced concrete structures is one of the most founded pathologies on the coastal area. With the objective to prevent the process development, or even, retard its beginning, it was studied the application of inorganic covering over concrete surfaces, after its cure, as well as, evaluate the efficiency of the covering applied on the concrete in reducing its porosity of concrete preventing the entrance of aggressive agents to preserve the integrity of the existing armor inside it, comparing the result obtained with the body-of-proof reference, that didn´t receive covering protection. On the concrete production it was used Portland Cement CP II 32, coarse aggregate, fine aggregate and water from the local distributive. Two types of covering were used, one resin based of silicon and solvent and other white cement based, selected sands and acrylic resin. The concrete mixture adopted was 1:1,5:2,5 (cement, fine aggregate, coarse aggregate) and 0.50 water/cement ratio. With the concrete on fresh state was made the experiment test to determinate the workability. On the hardened state was made the concrete resistance experiment, absorption of water and electrochemical experiments, through polarization curves. Also was held optical microscopy and Scanning Electron Microscopy experiments to analyze the layer of the covering applied to the concrete surface and the interface between the concrete and the layer. The obtained results shows that the covering applied to the concrete surface didn´t affect the resistance towards compression. On the absorption of water occurred a diminution of the percentage absorbed, improving the concrete development by making it more impermeable towards the entrance of aggressive agents. The electrochemical experiment results confirmed the water absorption results; the body-of-proof covered presented larger protection towards the development of corrosives process and retarded the evolution of the corrosive phenomenon

Construção, caracterização e aplicação de eletrodos para descarga por arco de cátodo oco

The system built to characterize electrodes and, consequently, deposited fine films are constituted by a hollow cathode that works to discharges and low pressures (approximately 10-3 to 5 mbar), a source DC (0 to 1200 V), a cylindrical camera of closed borossilicato for flanges of stainless steel with an association of vacuum bombs mechanical and spread. In the upper flange it is connected the system of hollow cathode, which possesses an entrance of gas and two entrances for its refrigeration, the same is electrically isolated of the rest of the equipment and it is polarized negatively. In front of the system of hollow cathode there is a movable sample in stainless steel with possibility of moving in the horizontal and vertical. In the vertical, the sample can vary its distance between 0 and 70 mm and, in the horizontal, can leave completely from the front of the hollow cathode. The sample and also the cathode hollow are equipped with cromel-alumel termopares with simultaneous reading of the temperatures during the time of treatment. In this work copper electrodes, bronze, titanium, iron, stainless steel, powder of titanium, powder of titanium and silício, glass and ceramic were used. The electrodes were investigated relating their geometry change and behavior of the plasma of the cavity of hollow cathode and channel of the gas. As the cavity of hollow cathode, the analyzed aspects were the diameter and depth. With the channel of the gas, we verified the diameter. In the two situations, we investigated parameters as flow of the gas, pressure, current and applied tension in the electrode, temperature, loss of mass of the electrode with relationship at the time of use. The flow of gas investigated in the electrodes it was fastened in a work strip from 15 to 6 sccm, the constant pressure of work was among 2.7 to 8 x 10-2 mbar. The applied current was among a strip of work from 0,8 to 0,4 A, and their respective tensions were in a strip from 400 to 220 V. Fixing the value of the current, it was possible to lift the curve of the behavior of the tension with the time of use. That curves esteem in that time of use of the electrode to its efficiency is maximum. The temperatures of the electrodes were in the dependence of that curves showing a maximum temperature when the tension was maximum, yet the measured temperatures in the samples showed to be sensitive the variation of the temperature in the electrodes. An accompaniment of the loss of mass of the electrode relating to its time of use showed that the electrodes that appeared the spherical cavities lost more mass in comparison with the electrodes in that didn't appear. That phenomenon is only seen for pressures of 10-2 mbar, in these conditions a plasma column is formed inside of the channel of the gas and in certain points it is concentrated in form of spheres. Those spherical cavities develop inside of the channel of the gas spreading during the whole extension of the channel of the gas. The used electrodes were cut after they could not be more used, however among those electrodes, films that were deposited in alternate times and the electrodes that were used to deposit films in same times, those films were deposited in the glass substrata, alumina, stainless steel 420, stainless steel 316, silício and steel M2. As the eletros used to deposit films in alternate time as the ones that they were used to deposit in same times, the behavior of the thickness of the film obeyed the curve of the tension with relationship the time of use of the electrode, that is, when the tension was maximum, the thickness of the film was also maximum and when the tension was minimum, the thickness was minimum and in the case where the value of the tension was constant, the thickness of the film tends to be constant. The fine films that were produced they had applications with nano stick, bio-compatibility, cellular growth, inhibition of bacterias, cut tool, metallic leagues, brasagem, pineapple fiber and ornamental. In those films it was investigated the thickness, the adherence and the uniformity characterized by sweeping electronic microscopy. Another technique developed to assist the production and characterization of the films produced in that work was the caloteste. It uses a sphere and abrasive to mark the sample with a cap impression, with that cap form it is possible to calculate the thickness of the film. Through the time of life of the cathode, it was possible to evaluate the rate of waste of its material for the different work conditions. Values of waste rate up to 3,2 x 10-6 g/s were verified. For a distance of the substratum of 11 mm, the deposited film was limited to a circular area of 22 mm diameter mm for high pressures and a circular area of 75 mm for pressure strip. The obtained films presented thickness around 2,1 µm, showing that the discharge of arch of hollow cathode in argon obeys a curve characteristic of the tension with the time of life of the eletrodo. The deposition rate obtained in this system it is of approximately 0,18 µm/min

Utilização de matérias primas vegetais para aplicabilidade como inibidores de corrosão

In the search for products that act as corrosion inhibitors and do not cause environmental, impact the use of plant extracts as corrosion inhibitors is becoming a promising alternative. In this work the efficiency of polar extracts (ethanol extracts) obtained from the plants Anacardium occidentale Linn (AO) and Phyllantus amarus Schum. & Thonn (PA) as corrosion inhibitors were evaluated in different concentrations. For that AO and PA extracts were solubilized in the microemulsion systems (SME) containing saponified coconut oil as surfactant (SME -OCS and SME-OCS-1) in saline (NaCl 3,5 %) solution, which was also used as electrolyte. Both SME-OCS and SME-OCS-1 were characterized by surface tension and viscosity methods showing a Newtonian fluid behavior. The SME-OCS and SME-OCS-1 systems satisfactorily solubilized the polar extracts AO and PA with measurements carried out by ultraviolet spectroscopy. The measurements of corrosion inhibition efficiencies were performed by the electrochemical linear polarization resistance (LPR) technique as well as weight loss, on the surface of AISI 1020 carbon steel. The maximum corrosion inhibition efficiencies were determined by extrapolation of Tafel plots, showing the following values: 95,6 % for the system SME-OCS-AO, 98,9 % for the system SME-OCS-AO-1 and 93,4 % for the system SME-OCS-PA

Utilização de nanosílica como aditivo estendedor para pastas cimentantes de baixa densidade destinadas à cimentação de poços petrolíferos

Cementing operations are conducted at different times of the well s life and they have high importance, because the functions are fundamental to keep good properties during a long life of the well, such as, maintain the mechanical stability of the well, to promote the isolation hydraulic and support the tubing. In some situations, the rocky zones have low fractures pressures and require the use of lightweight slurries to prevent the hydrostatic pressure in the formation is greater than the pressure of fracture. There are three ways to reduce the density of cement slurries: exterders water additives, microspheres and foamed slurries. The most used extender water additive is sodium bentonite, which is a clay with a good capacity of water absorption and expansion of its volume, the main disadvantage of this additive is the reduction of the strength. Currently, the use of nanoscale particles has received special attention, mainly because they get new functionalities. Following this trend, this paper aims to use a colloidal solution of nano-silica as an exterders water additives for use in oil wells. Slurries were designed with fixed 13lb/gal density and concentration of nano silica 0.1 gpc; 0.4 gpc; 0.7 and 1gpc, the influence of nano-silica was studied at these levels in isolation and combined varying concentrations of CaCl2,. Tests including rheology, stability, strength, thickening time, porosity and permeability. Besides the API tests, microstructural characterizations were performed after 28 days of the slurries, X-ray diffraction (XRD) and scanning electron microscopy (SEM)

Desenvolvimento e caracterização de compósito a partir da borra da piaçava para construção da parábola de um fogão solar a concentração

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Aproveitamento de resíduo de beneficiamento do caulim na produção de porcelanato cerâmico

Nowadays, industries from all sectors have great concerns over the disposition of the residues generated along the productive process. This is not different in the mineral sector, as this generates great volumes of residues. It was verified that the kaolin improvement industry generates great volumes of residue basically constituted of kaolinite, muscovite mica and quartz, which are basic constitution elements to formularisations of ceramics masses to the production of covering of stoneware tiles type. This happens because the methodology applied to the improvement process is still very rudimentary, what causes a very low yield, only ¼ from all the material volume that enters the improvement process, in the end, is marketable. The disposal of this residue, in a general way, causes a very big negative environmental impact, what has justified the researches efforts aiming to find a rational solution to this problem. In this way, the intention of this present work is the utilization of this residue in the manufacture of products to high quality ceramics covering, stoneware tiles in an industrial scale. For this purpose, the influence of the addition of the residue to a standard ceramics mass used by a ceramics sector company, already established in the market, with the intention of verifying the possibility of use of this residue as the mass complementary raw material and even the possible partial or total substitution of one of the components of the mass for the raw material in evidence will be studied. To the accomplishment of this work, the kaolin improvement residue generated by an industry of exploitation and improvement of kaolin, located in the region of Equador-RN, in the levels 1,2,4,8, 16 and 32% will be added to the standard mass already used for the production of stoneware tiles. The raw materials used, kaolin residue and the standard mass, were characterized through DRX, FRX, DTA, TGA and dilatometry. After the sintering of the bodies of test, tests of water absorption, apparent porosity, post burning linear retraction, apparent specific mass and flexural strength (3 point bending) were realized to determinate the technological properties of these materials. The results show the studied residue can be considered raw material of great potential to the industry of floor and ceramics covering of the stoneware tiles type

Filtro kl/dvs para atenuação do ruído "ground roll"

In geophysics there are several steps in the study of the Earth, one of them is the processing of seismic records. These records are obtained through observations made on the earth surface and are useful for information about the structure and composition of the inaccessible parts in great depths. Most of the tools and techniques developed for such studies has been applied in academic projects. The big problem is that the seismic processing power unwanted, recorded by receivers that do not bring any kind of information related to the reflectors can mask the information and/or generate erroneous information from the subsurface. This energy is known as unwanted seismic noise. To reduce the noise and improve a signal indicating a reflection, without losing desirable signals is sometimes a problem of difficult solution. The project aims to get rid of the ground roll noise, which shows a pattern characterized by low frequency, low rate of decay, low velocity and high amplituds. The Karhunen-Loève Transform is a great tool for identification of patterns based on the eigenvalues and eigenvectors. Together with the Karhunen-Loève Transform we will be using the Singular Value Decomposition, since it is a great mathematical technique for manipulating data

Contribuição ao desenvolvimento de ontologias para processos petroquímicos : estudo de caso em uma planta DEA

In the last decades, the oil, gas and petrochemical industries have registered a series of huge accidents. Influenced by this context, companies have felt the necessity of engaging themselves in processes to protect the external environment, which can be understood as an ecological concern. In the particular case of the nuclear industry, sustainable education and training, which depend too much on the quality and applicability of the knowledge base, have been considered key points on the safely application of this energy source. As a consequence, this research was motivated by the use of the ontology concept as a tool to improve the knowledge management in a refinery, through the representation of a fuel gas sweetening plant, mixing many pieces of information associated with its normal operation mode. In terms of methodology, this research can be classified as an applied and descriptive research, where many pieces of information were analysed, classified and interpreted to create the ontology of a real plant. The DEA plant modeling was performed according to its process flow diagram, piping and instrumentation diagrams, descriptive documents of its normal operation mode, and the list of all the alarms associated to the instruments, which were complemented by a non-structured interview with a specialist in that plant operation. The ontology was verified by comparing its descriptive diagrams with the original plant documents and discussing with other members of the researchers group. All the concepts applied in this research can be expanded to represent other plants in the same refinery or even in other kind of industry. An ontology can be considered a knowledge base that, because of its formal representation nature, can be applied as one of the elements to develop tools to navigate through the plant, simulate its behavior, diagnose faults, among other possibilities

Estudo comparativo da injeção de água usando poços verticais e horizontais

Oil recovery using waterflooding has been until now the worldwide most applied method, specially for light oil recovery, its success is mainly because of the low costs involved and the facilities of the injection process. The Toe- To-Heel Waterflooding TTHWTM method uses a well pattern of vertical injector wells completed at the bottom of the reservoir and horizontal producer wells completed at the top of it. The main producing mechanism is gravitational segregation in short distance. This method has been studied since the early 90´s and it had been applied in Canada with positive results for light heavy oils, nevertheless it hasn´t been used in Brazil yet. In order to verify the applicability of the process in Brazil, a simulation study for light oil was performed using Brazilian northwest reservoirs characteristics. The simulations were fulfilled using the STARS module of the Computer Modelling Group Software, used to perform improved oil recovery studies. The results obtained in this research showed that the TTHWTM well pattern presented a light improvement in terms of recovery factor when compared to the conventional 5- Spot pattern, however, it showed lower results in the economic evaluation

Análise de Sustentabilidade em Projetos de Instalações de Produção de Petróleo

A proposal for a global analysis of sustainability in projects related in oil facilities is presented. By considering economic, environmental and social aspects in the early stages of design, the suggested method is more comprehensive and can be used to complement the analysis commonly applied in the petroleum industry, such as: Study of Technical and Economic Feasibility; Environmental Impact Assessment and Risk Analysis. Several authors, associations, certification bodies and oil companies suggest different approaches to study sustainability in some specific activities (or industries). In this study, a checklist of significant sustainability aspects for the oil industry (surface facilities) was assembled. In addition, a matrix was developed to assess the sustainability items relevant to these projects. In this work, the checklist interacts with the matrix to perform a "Preliminary Analysis of Sustainability of the Enterprise" (APSE). This method allows the identification of aspects that contribute significantly to global sustainability. From this analysis, which includes economic, social and environmental aspects, is built a report that is used to analyze qualitatively and quantitatively the impact of the sustainability aspects of the project. In this analysis are identified items that strongly influence the economic, social or environmental aspects and evaluated alternatives that can increase the overall sustainability of the project. Finally, the alternatives that can be used to indicate the most sustainable option are identified. This method was applied in a project (design) of a small offshore platform. This case study shows how the APSE can contribute to the identification of sustainability initiatives for the enterprise. The results showed that relevant aspects can contribute decisively to global sustainability. Finally, it was observed that the proposed method can contribute to increased rates of sustainability, even after application of analysis commonly used in these projects

Ciência e espiritualidade: conversas com pacientes terminais

It has been reflected on Science and spirituality having as focus the relation between them and the process lived by terminal patients after the confirmation of the finitude of their lives. It has searched with this research to excite discussions that corroborate the tematization of a possible dialogue between science and spirituality, signaling perspectives of debates and formation of an understanding of the problematic that involves these human constructs in the development of alternatives for the understanding of the life finitude. We point out the moment of split between science and spirituality through the cartesian paradigm from a historical approach and after focusing the illness and death as foundation for our discussion. We use as methodological strategy, focal talks with terminal patients having as guidance a guideline with five punctuations: the singular citizen, diagnosis impacts, indicators of science, spirituality marks and death fear that served of base for analysis and data interpretation in according to selected theoretical foundations. Thus, it was possible to perceive that science, although not to keep an explicit dialogue with spirituality, it has pointed through is representation forms to the process indicatives that will culminate with the death. And these indicators had shown that in this direction it is efficient. We believe that the confrontation of the death can happen through of a new science that dialogues with the spirituality, where does not have separation between reason and emotion on the part of science; as well as it does not have reason disdain on the part of the spirituality

Ciência como montagem, montagem como ciência

The thesis describes parallel possibilities between the knowledge built in theatre and in Science. The narrative is constructed through a reflexive observation of the process of making a threatical play, specifically O Tempo da Chuva by Grupo Beira de Teatro , in analogy to the process of making a scientific theory, specifically the one described by Werner Heisenberg in his book Physics and Beyond: encounters and conversations . It sets a dialog with authors/actors from various areas of knowledge, such as Edgar Morin, Werner Heisenberg, René Descartes, Paul Feyerabend, Paul Caro, Juremir Machado da Silva, Maria da Conceição de Almeida, Renato Ferracini, among others. It discusses the hypothesis that Science is the process of building and the theatrical process of building a play can also be systematized, likewise science. The thesis defends, as the complexities science may suggest, a method as a strategy. Developed throughout the process, such method could only be verified at the end, when the elements of the setting of atomic physics theories and theatre were correlated. Questions such as: the place of theatre and science in our contemporary society and the political and ethical role of artists and scientists are at the episthemological basis of this narrative which we have started, but it is not even close to a conclusion

Os embates entre ciência e política na experiência parlamentar de Josué de Castro

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

A etnopoética de Iracema: diálogo, ciência e literatura

Literary works are thought provokers that make it possible to access several forms to view the world and reality. They provide diversified points of view and infinite connections. In a particular way, among all the other forms of art expression literature is considered to be the closest to life, once it is able to reconnect all human dimensions emotional, rational, mystic, personal, universal, corporal, historic, mythical. This thesis aims at offering some reflections about the frontiers and bridges between science and literature aiming at understanding the complexity that guides them. It presents a new reading of Iracema novel: Ceará tale of José de Alencar from a meticulous incursion through new ways and natural spaces interwoven by Alencar. It tries to hear the echoes of this indianist novel in the university students today. In a broader context, it creates arguments that question the multiple threadsthat join science and literature so that a science of complexity arises distinguishing but not separating the innumerous narratives about the world. For this purpose, this thesis has as interlocutors: Antonio Candido, Charles P. Snow, Edgar Morin, Emilio Ciurana, Fritjof Capra, George Steiner, Ilya Prigogine, Isabelle Stengers, Roger Chartier, Roland Barthes. The plot presented here does not limit the novel to science, but makes it a rereading of the word, of life, once this is the raw material of books. As a methodological strategy, we rebuilt Iracema´s character trips in a way to update the novel, resulting in the video documentary Iracema ways: the arid and remote interior, the plateau, the sea. Iracema novel and character enhancing dialogs that allow the dichotomy rupture between two cultures (Charles P. Snow), recognizing they are not incommunicable and revealing the core argument of the thesis: Iracema belongs to a complex category. It is a hybrid novel that is far, far away from that bluish plateau in the horizon