Análise tribológica de um sistema de acionamento alternativo de pigs para a indústria do petróleo

It is analyzed through the concepts of tribology and mechanical contact and damage the suggestion of implementing a backup system for traction and passage of Pipeline Inspection Gauge (Pig) from the inside of pipelines. In order to verify the integrity of the pipelines, it is suggested the possibility of displacement of such equipment by pulling wires with steel wires. The physical and mechanical characteristics of this method were verified by accelerated tests in the laboratory in a tribological pair, wire versus a curve 90. It also considered the main mechanisms of wear of a sliding system with and without lubricant, in the absence and presence of contaminants. To try this, It was constructed a test bench able to reproduce a slip system, work on mode back-and-forth ("reciprocation"). It was used two kinds of wires, a galvanized steel and other stainless steel and the results achieved using the two kinds of steel cables were compared. For result comparative means, it was used steel cables with and without coating of Poly Vinyl Chloride (PVC). The wires and the curves of the products were characterized using metallographic analysis, microhardness Vickers tests, X-ray diffraction (XRD), X-Ray Refraction (XRF) and tensile tests. After the experiments were analyzed some parameters that have been measurable, it demonstrates to the impracticality of this proposed method, since the friction force and the concept of alternating request at the contact between the strands of wire and the inner curves that are part ducts caused severe wear. These types of wear are likely to cause possible failures in future products and cause fluid leaks

Estudo numérico de escoamento turbulento em padrão anular gás-líquido em dutos verticais

Multiphase flows in ducts can adopt several morphologies depending on the mass fluxes and the fluids properties. Annular flow is one of the most frequently encountered flow patterns in industrial applications. For gas liquid systems, it consists of a liquid film flowing adjacent to the wall and a gas core flowing in the center of the duct. This work presents a numerical study of this flow pattern in gas liquid systems in vertical ducts. For this, a solution algorithm was developed and implemented in FORTRAN 90 to numerically solve the governing transport equations. The mass and momentum conservation equations are solved simultaneously from the wall to the center of the duct, using the Finite Volumes Technique. Momentum conservation in the gas liquid interface is enforced using an equivalent effective viscosity, which also allows for the solution of both velocity fields in a single system of equations. In this way, the velocity distributions across the gas core and the liquid film are obtained iteratively, together with the global pressure gradient and the liquid film thickness. Convergence criteria are based upon satisfaction of mass balance within the liquid film and the gas core. For system closure, two different approaches are presented for the calculation of the radial turbulent viscosity distribution within the liquid film and the gas core. The first one combines a k- Ɛ one-equation model and a low Reynolds k-Ɛ model. The second one uses a low Reynolds k- Ɛ model to compute the eddy viscosity profile from the center of the duct right to the wall. Appropriate interfacial values for k e Ɛ are proposed, based on concepts and ideas previously used, with success, in stratified gas liquid flow. The proposed approaches are compared with an algebraic model found in the literature, specifically devised for annular gas liquid flow, using available experimental results. This also serves as a validation of the solution algorithm

Modelagem numérica de escoamento em padrão anular com transferência de calor e massa

Annular flow is the prevailing pattern in transport and energy conversion systems and therefore, one of the most important patterns in multiphase flow in ducts. The correct prediction of the pressure gradient and heat transfer coefficient is essential for optimizing the system s capacity. The objective of this work is to develop and implement a numerical algorithm capable of predicting hydrodynamic and thermal characteristics for upflow, vertical, annular flow. The numerical algorithm is then complemented with the physical modeling of phenomena that occurs in this flow pattern. These are, turbulence, entrainment and deposition and phase change. For the development of the numerical model, axial diffusion of heat and momentum is neglected. In this way the time-averaged equations are solved in their parabolic form obtaining the velocity and temperature profiles for each axial step at a time, together with the global parameters, namely, pressure gradient, mean film thickness and heat transfer coefficient, as well as their variation in the axial direction. The model is validated for the following conditions: fully-developed laminar flow with no entrainment; fully developed laminar flow with heat transfer, fully-developed turbulent flow with entrained drops, developing turbulent annular flow with entrained drops, and turbulent flow with heat transfer and phase change

Avaliação da molhabilidade de soluções de tensoativos em aço inoxidável

With the increasing industrialization of the planet caused by globalization, it has become increasingly common to search for highly resistant and durable materials for many diverse branches of activities. Thus, production and demand for materials that meet these requirements have constantly increased with time. In view of this, stainless steel is presented as one of the materials which are suitable applications, due to many features that are interesting for several segments of the industry. Concerns of oil companies over heavy oil reservoirs have grown steadily for the last decades. Rheological properties of these oils impair their transport in conventional flow systems. This problem has created the need to develop technologies to improve flow and transport, reducing operation costs so as to enable oil production in the reservoir. Therefore, surfactant-based chemical systems are proposed to optimize transport conditions, effected by reduction of interfacial tensions, thereby enhancing the flow of oil in ducts and reducing load losses by friction. In order to examine such interactions, a study on the wettability of metallic surfaces has been undertaken, represented by measuring of contact angle of surfactant solutions onto flat plates of 304 stainless steel. Aqueous solutions of KCl, surfactants and mixtures of surfactants, with linear and aromatic hydrocarbon chain and ethoxylation degrees ranging between 20 to 100, have been tested. The wettability was assessed by means of a DSA 100 krüss goniometer. The influence of roughness on the wettability was also investigated by machining and polished the stainless steel plates with sandpapers of references ranging between 100 of 1200. The results showed that sanding and polishing plates result in decrease of wettability. As for the solutions, they have provided better wettability of the stainless steel than the KCl solutions tested. It was also been concluded that surfactant mixtures is an option to be considered, since they promote interactions that generate satisfactory contact angles for a good wettability on the stainless steel plate. Another conclusion refers to the influence of the ethoxylation degree of the nonionic surfactant molecules on wettability. It has been observed that contact angles decrease with decreasing ethoxylation degrees. This leads us to conclude that molecules with higher ethoxylation degree, being more hydrophobic, decrease the interaction of water with the ducts, thereby reducing friction and improving the flow

Efeitos dos esteroides anabólicos androgênicos sobre o útero e parâmetros reprodutivos de ratas adultas

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

Nandrolone Decanoate and Physical Effort: Histological and Morphometrical Assessment in Adult Rat Uterus

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

Phenolic compounds in leaves of Alchornea triplinervia: anatomical localization, mutagenicity, and antibacterial activity

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

O conceito de liberdade em o ser e o nada de Jean-Paul Sartre

This dissertation aims to address the concept of freedom from the perspective of the French philosopher Jean-Paul Sartre with reference to the main work Being and Nothingness. After presenting the concept of freedom we will try to show that it is related to the notion of responsibility, which will lead, ultimately, to define the Sartrean philosophy as a philosophy of action. In the first chapter we will present in passing the phenomenology of Edmund Husserl, philosopher from which Sartre will develop his concept of freedom. The Husserlian notion of consciousness (intentionality) is the way to develop his analysis of Sartre phenomenon of being. From this analysis Sartre submits their concepts of being in-itself and being for-itself. Being initself is defined as the things of the world devoid of consciousness, are the things that surround us. The In-itself has as its main brand positivity: it is what it is, is all that can be said about him. In turn being For-itself is the very being of man, which differs radically from the In-itself. The For-itself has as its main intentionality, ie, its ability to project outside itself in existence. That's when Sartre shows that this type of being realizes its existence on the basis of a constant nihilation. Here comes the notion of anything. Among the relations of the For-itself with the surrounding world stands a very special: relationship between consciousnesses. It is when we discuss the issue of another. Intersubjectivity, through sartrean analysis of look, show that the For-itself assumes a new existential dimension: the being-for others. That's when Sartre will emphasize his notion of conflict. The conflict in intersubjectivity would come from the fact that you want to take another- For-itself as an object. Given this we will analyze what Sartre called the concrete relations with others. The philosopher submit such relations in the form of ducts and conduits assimilation of ownership. In the first my-self to try to "get lost" in the consciousness of another, ownership of my conduct in-itself tries to "take ownership" of the subjectivity of the other and try to treat others as things, as objects. In this sense Sartre examines the experiences of love, masochism, indifference, desire and sadism. Following this route we will enter the land of freedom itself, which is the major theme of our work. Since Sartre defines the For-itself as a being that is projected to create your way of being, it can only define it as freedom. The freedom of the For-itself is taken in terms of autonomy of choice. Once the For-itself has no way of being a thing as being in-itself, it just may be picking up, that is, making your being. Here Sartre speaks of the anguish that would be the symptom of freedom itself. The fact that the For-itself have to choose on whether the call as one being distressed. However, in most cases the For-itself tries to escape from the anguish of freedom and takes refuge in bad faith. After setting the man (For-itself) as freedom Sartre defends that he is totally responsible for what he does of himself. Once the philosopher holds that man is not predetermined, ie, does not have an a priori essence, his philosophy has as its basic assumption the action. If Sartre argues that the For-itself must constantly choose your way of being, the action is the basis on which man will exercise his own freedom. In this sense we conclude the work with an approach to work Existentialism is a Humanism, which represent the entry of the philosopher on the practical aspects of life

Testicular structure and description of the seminal pathway in Leporinus macrocephalus (Anostomidae, Teleostei)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Morphological Features of the Apical Region in the Principal Cells of Mongrel Dog Epididymis

The epithelial principal cells are the predominant cell type of the epididymis. These cells have been shown to be both secretory and endocytic cells. The apical region of the cytoplasm of principal cells in the mongrel dog are located close to the cell apex and tubular lumen, and shown microvilli at the luminal border and present a endocytic apparatus, that consists of coated pits and vesicles, endosomes of varying size, multivesicular bodies, and lysosomes. The endosomes, multivesicular bodies and lysosomes contained the electron-dense patches. These results suggest that principal cells of the epididymis in the dog as possess a highly developed endocytic apparatus play a role in endocytosis. These cells function are similarly to the related in other mammals, in performing endocytosis.

Line-pack management for producing electric power on peak periods

The distribution of natural gas is carried out by means of long ducts and intermediate compression stations to compensate the pressure drops due to friction. The natural gas compressors are usually driven by an electric motor or a gas turbine system, offering possibilities for energy management, one of these consisting in generating energy for use in-plant or to commercialize as independent power producer. It can be done by matching the natural gas demand, at the minimum pressure allowed in the reception point, and the storage capacity of the feed duct with the maximum compressor capacity, for storing the natural gas at the maximum permitted pressure. This allows the gas turbine to drive an electric generator during the time in which the decreasing pressure in duct is above the minimum acceptable by the sink unit. In this paper, a line-pack management analysis is done for an existing compression station considering its actual demand curve for determining the economic feasibility of maintaining the gas turbine system driver generating electricity in a peak and off-peak tariff structure. The potential of cost reduction from the point of view of energy resources (natural gas and electric costs) is also analyzed. (C) 2010 Elsevier Ltd. All rights reserved.

Influência do estado nutricional materno em vitamina A sobre os níveis de imunoglobulina A no colostro humano

Mothers with good vitamin A nutritional status during gestation and lactation are better able to nourish and protect their infant with maternal milk. Our hypothesis is that women with more serum retinol have more retinol and secretory immunoglobulin A in colostrum. 190 healthy puerperal women from a Brazilian public maternity were recruited and divided according to the cutoff point for serum retinol (30 μg/dL). A number of the women was supplemented with 200000 UI (60 mg) of retinyl palmitate in the immediate postpartum. Serum and colostrum were collected on the 1st day postpartum and colostrum again on the following day. Retinol (serum and colostrum) was analyzed by HPLC and SIgA (colostrum) by turbidimetry. The mothers presented with adequate biochemical indicators of nutritional status, according to serum retinol (44.6 μg/dL). There were significant differences (p= 0.0017 and p= 0.043, respectively) in retinol and SIgA levels in the colostrum of mothers with serum retinol > 30 μg/dL and < 30 μg/dL. The concentration of SIgA in the colostrum of non-supplemented mothers on the 1st day postpartum was 822.6 mg/dL, decreasing after 24 hours to 343.7 mg/dL. Supplemented mothers showed levels of SIgA in colostrum of 498.9 mg/dL on the 2nd day postpartum (p= 0.00006). The colostrum of women with good vitamin A nutritional status had more retinol and SIgA. Additionally, maternal supplementation increases the levels of SIgA in colostrum. The higher levels of SIgA on the 1st day postpartum showed the importance of early breastfeeding, given that it provides considerable immunological benefits to newborn infants

Direct effects of colchicine on myocardial function - Studies in hypertrophied and failing spontaneously hypertensive rats

The aging spontaneously hypertensive rat (SHR) is a model in which the transition from chronic stable left ventricular hypertrophy to overt heart failure can be observed. Although the mechanisms for impaired function in hypertrophied and failing cardiac muscle from the SHR have been studied, none accounts fully for the myocardial contractile abnormalities. The cardiac cytoskeleton has been implicated as a possible cause for myocardial dysfunction. If an increase in microtubules contributes to dysfunction, then myocardial microtubule disruption by colchicine should promote an improvement in cardiac performance. We studied the active and passive properties of isolated left ventricular papillary muscles from 18- to 24-month-old SHR with evidence of heart failure (SHR-F, n=6), age-matched SHR without heart failure (SHR-NF, n=6), and age-matched normotensive Wistar-Kyoto rats (WKY, n=5). Mechanical parameters were analyzed before and up to 90 minutes after the addition of colchicine (10(-5), 10(-4), and 10(-3) mol/L). In the baseline state, active tension (AT) developed by papillary muscles from the WKY group was greater than for SHR-NF and SHR-F groups (WKY 5.69+/-1.47 g/mm(2) [mean+/-SD], SHR-NF 3.41+/-1.05, SHR-F 2.87+/-0.26; SHR-NF and SHR-F P<0.05 versus WKY rats). The passive stiffness was greater in SHR-F than in the WKY and SHR-NF groups (central segment exponential stiffness constant, K-cs: SHR-F 70+/-25, SHR-NF 44+/-17, WKY 41+/-13 [mean+/-SD]; SHR-F P<0.05 versus; SHR-NF and WKY rats). AT did not improve after 10, 20, and 30 minutes of exposure to colchicine (10(-5), 10(-4), and 10(-3) mol/L) in any group. In the SHR-F group, AT and passive stiffness did not change after 30 to 90 minutes of colchicine exposure (10(-4) mol/L). In summary, the data in this study fail to demonstrate improvement of intrinsic muscle function in SHR with heart failure after colchicine. Thus, in the SHR there is no evidence that colchicine-induced cardiac microtubular depolymerization affects the active or passive properties of hypertrophied or failing left ventricular myocardium.

Comprometimento da pálpebra e via lacrimal excretora em portador de leishmaniose cutâneo-mucosa: relato de caso

Objetivo: Apresentar um portador de leishmaniose com lesão palpebral e dilatação de via lacrimal excretora. Relato de caso: O paciente em questão foi portador de leishmaniose do tipo cutâneo-mucosa, tendo apresentado múltiplas lesões de pele, ectrópio da pálpebra inferior, lesões na mucosa nasal e alterações na drenagem lacrimal. Discussão: O acometimento da pálpebra e da via lacrimal raramente ocorre em portadores de leishmaniose. Os autores chamam atenção para o diagnóstico e para a necessidade de se adotar medidas preventivas contra os vetores e a rápida instituição do tratamento.

Lacrimal excretory system sequelae in patients treated for leishmaniasis

A leishmaniose pode destruir os tecidos nasais resultando em alterações da via lacrimal excretora. OBJETIVO: Avaliar a ocorrência de alterações do sistema lacrimal excretor em portadores de leishmaniose na fase de pós-tratamento. MÉTODOS: Foi realizada a avaliação da via lacrimal excretora em 45 portadores de leishmaniose tratada (90 vias lacrimais) pelo teste de Jones I. Treze pacientes (26 ductos nasolacrimais) tiveram o teste de Jones I alterado, tendo sido submetidos a dacriocistografia e endoscopia nasal. RESULTADOS: A maioria dos indivíduos avaliados apresentava a leishmaniose na forma cutânea (64,4%). Entretanto, 69,23% dos indivíduos com alteração do sistema lacrimal excretor apresentavam a forma mucocutânea antes do tratamento. A alteração mais freqüentemente detectada foi ducto nasolacrimal permeável e dilatado (92,30%). Apenas 3,84% (1/26) das vias lacrimais estavam obstruídas. A endoscopia nasal mostrou hipertrofia de corneto (53,84%), desvio de septo (53,84%) e perfuração do septo nasal (23,07%). CONCLUSÃO: em portadores de leishmaniose tratada encontra-se como seqüela mais freqüente no sistema excretor lacrimal as vias lacrimais permeáveis e dilatadas.