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 de formulação de massa para aplicação em placas cerâmicas

The sector of civil construction is strongly related to the red ceramic industry. This sector uses clay as raw material for manufacturing of various products such as ceramic plates. In this study, two types of clay called clay 1 and clay 2 were collected on deposit in Ielmo Marinho city (RN) and then characterized by thermogravimetric analysis (TG/DTG), differential thermal analysis (DTA), X-ray diffraction (XRD), X-ray fluorescence (XRF), rational analysis and particle size distribution and dilatometric analyses. Ceramic plates were manufactured by uniaxial pressing and by extrusion. The plates obtained by pressing were produced from the four formulations called 1, 2, 3 and 4, which presented, respectively, the following proportions by mass: 66.5% clay 1 and 33.5% clay 2, 50% clay 1 and 50% clay 2, 33.5% clay 1 and 66.5% clay 2, 25% clay 1 and 75% clay 2. After firing at 850, 950 and 1050 °C with heating rate of 10 °C/min and soaking time of 30 minutes, the following technological properties were determined: linear firing shrinkage, water absorption, apparent porosity, apparent specific mass and tensile strength (3 points). The formulation containing 25% clay 1 produced plates with most satisfactory results of water absorption and mechanical resistance, because of that it was chosen for manufacturing plates by extrusion. A single firing cycle was established for these plates, which took place as follow: heating rate of 2 °C/min up to 600 ºC with soaking time of 60 minutes, followed by heating using the same rate up to 1050 ºC with soaking time of 30 minutes. After this cycle, the same technological properties investigated in the plates obtained by pressing were determined. The results indicate (according to NRB 13818/1997) that the plates obtained by pressing from the mixture containing 25 wt% clay 1, after firing at 1050 °C, reach the specifications for semi-porous coating (BIIb). On the other hand, the plates obtained by extrusion were classified as semi-stoneware (group AIIa)

Análise de desempenho de um fogão solar com parabola fabricada em material compósito

It is presented a solar cooker made with a parabolic reflector composed by a composite material. For this purpose, it was utilized a cast concrete with a parabolic profile obtained by means of modeling. It will be demonstrated the manufacturing process and settings, as well as tests results, in order to determine the contact temperature and cooking time of some foods. This solar cooker presents the following main characteristics: the concentration method, low cost and easy manufacturing process. It was performed by employing recycled materials such as cement, plaster, crushed polystyrene and wheels. The captation area measures 1 square meter and its parabole was covered with a mirrors measuring 25 cm2. A temperature higher than 650°C was obtained. Furthermore, it has been demonstrated that the cooking viability for several type of foods such as beans, potatoes, rice, yams and pasta can be used in two meals for a family of four. In addition, the advantages of this cooker were analysed in comparison with others described in literature as well as those operating on gas. Especially in Northeast of Brazil, where there is a potential for solar energy, this prototype is an important tool, because it avoids not only desertification, but also pollutants from burning firewoods which cause ecological imbalance

Desenvolvimento e análise de material compósito a base de penas de frango (fibras de queratina-KF) e matriz de poliéster insaturado

Use of natural fibres as a reinforcement material in the manufacture of composites show a series of advantages: availability, biodegradability, low weight and regeneration in relation to synthetic fibres, thus justifying its utilization. In the present research work, composites were developed with chicken feathers (KF), using unsaturated polyester resin as matrix, for diversified applications, mainly in the furniture/timber industry.At present, in Brazil the chicken feathers are used as part of the animal feed, even though this material possesses low aggregated value. The chicken feathers are hollow, light and resistant. After washing with water at room temperature, a part of the chicken feathers were treated with 2% NaOH. Composites were manufactured using treated and untreated chicken feathers with unsaturated orthothalic polyester resin and 1% peroxide as catalyser, obtained in the commerce. Samples with size 150x25x3 mm for mechanical tests were cut by laser in the composite plate. Mechanical analyses were carried out in the Laboratório de Metais e Ensaios Mecânicos UFRN. All the analyses were in accordance with ASTM standards. SEM analyses were also carried out on the samples.In the analyses of the results obtained, it was observed that the composites made with untreated chicken feathers showed better results (Traction 11.406 MPa and 9.107 MPa Bending 34.947 and 20.918 MPa for samples with and without treatment respectively) compared to the composite with treated feathers. Very low values of the water absorption results, evidenced the impermeability characteristic of the feathers. From the SEM images, the structure, fracture and the fibre/matrix adsorption can be evidenced. In the flammability test, it was observed that despite the feathers having sulfur as a constituent, natural inhibitor of flame, no burning support of the composites, because the manufacturing process of the composite

Análise térmica e mecânica de um compósito de matriz cerâmica com carga de EPS e raspa de pneu para construção de casas populares

Space Science was built using a composite made of plaster, EPS, shredded tires, cement and water. Studies were conducted to thermal and mechanical resistance. Inside the mold EPS plates were placed in order to obtain a higher thermal resistance on the wall constructed, as well as to give it an end environmentally friendly in view of both the tire and the EPS occupy a large space in landfills and year need to be degraded when released into the environment. Compression tests were performed according to ABNT blocks to seal, measurements of the temperature variation in the external and internal walls using a laser thermometer and check the temperature of the indoor environment using a thermocouple attached to a digital thermometer. The experiments demonstrated the heat provided by the composite values from the temperature difference between the internal and external surfaces on the walls, reaching levels of 12.4 ° C and room temperature in the interior space of the Science of 33.3 ° C, remaining within the zone thermal comfort for hot climate countries. It was also demonstrated the proper mechanical strength of such a composite for sealing walls. The proposed use of the composite can contribute to reducing the extreme housing shortage in our country, producing popular homes at low cost and with little time to work

Estudo comparativo das propriedades mecânicas em compósitos da fibra modal e poliester

In the present work, three composites with distinct reinforcements (polyester, modal e polyester + modal), all if a unsaturated orthophthalic polyester resin as matrix were used, in order to conduct a comparative study by mechanical tests and water absorption. The fibre mats were prepared in a mat preparatory by immersion developed in the Textile Engineering Laboratory. The composites were manufactured using a closed mould process by compression using an unsaturated orthophthalic polyester resin as matrix and 1% MEK (methyl ethyl ketone peroxide) as an initiator. In each composite twelve samples with the dimensions of 150x25x3 mm were cut randomly for the mechanical analysis (tension x extension, three points bending and water absorption and Scanning Electron Micsroscopy). The mechanical tests were carried out in the Laboratório de Metais e Ensaios Mecânicos UFRN . All the analyses were carried out according to the ASTM norms. The resultant samples from the mechanical analysis were subjected for the Scanning Electron Microscopy analysis. Based on the results obtained, it was observed that the reinforced composite with two fibres (modal + polyester) presented better results in comparison to the other two composites both in the tension/extension as well on the three point bending tests. In the water absorption test, it was possible to observe an equilibrium in the water absorption by the modal and polyester composite, due to the union of the two fibres. In the SEM images, the regions of rupture in the composites as well as the adsorption between the fiber and the matrix could be observed

Fabricação de eco-composito com a fibra de lã canina

The Sustainability has been evidence in the world today; organizations have sought to be more and more into this philosophy in their processes, whether products or attendance. In the present work were manufactured eco-composites with animal fiber (dog wool) that is currently discarded into the environment without any use. The fibers were characterized and made matting (non-woven). The phases of the project were consisted to develop methods and to convert these fibers (booster) blended with polyester resin (matrix) in different proportions (10%, 20% and 30%) at the composite. Were studied fiber characteristics, mechanical properties of the composites, water absorption and scanning electron microscopy. Initially, the fibers were treated with solution of sodium hydroxide of 0.05 mols, and then taken to matting preparing at the textile engineering laboratory - UFRN. The composites were made by compression molding, using an orthophthalic polyester resin as matrix and 1% MEK (methyl ethyl ketone peroxide) as initiator (catalyst). To evaluate the mechanical tests (tensile and flexural) and water absorption were made twelve specimens with dimensions 150x25x3 mm were cut randomly. According to the standard method, tensile tests (ASTM 3039) bending tests (ASTM D790) were performed at the mechanical testing of metals at laboratory UFRN. The results of these tests showed that the composite reinforced with 30% had a better behavior when exposed to tension charge; while on the three points bending test showed that the composite reinforced with 10% had a better behavior. In the water absorption test it was possible to see that the highest absorption happened on the composite reinforced with 30%. In the micrographs, it was possible to see the regions of rupture and behavior of the composite (booster / matrix)

Morfologia e propriedades mecânicas da fibra de sisal unidirecional e em sobreposição de compósito com resina epóxi

The composites manufactured with long fibres aligned in a single direction, and overlay has been shown to have better performance than the short fibers randomly distributed. In particular, the lignocellulosic fibers extracted from the sisal leaves, used in conjunction with the epoxy resin has attracted the attention of many researchers because the final properties of the system formed. In this work composites based on epoxy resin reinforced with sisal fibers were manufactured. The sisal fibres were treated with an alkaline solution of 0.06 mol/l NaOH. The treated, and untreated fibres were subjected to tension x extension tests. The composites were manufactured in the "Lossy" mold with the specifications of the samples to be produced (300x20x4 mm). The tension tests were carried out in accordance with the ASTM standards 3039 (for the composite aligned in a single direction) and ASTM D5573 (for composites in overlay), three point bending tests were performed according to ASTM D790. Analyzing the results of the tests of tension and three point bending tests, it was observed that the composites with the configuration of overlapping had the better elastic module in both tests. As to the maximum resistance to tension, the best result was the composites aligned in a single direction. Tests of absorption of water and micrographs are in progress

Viabilidade de uso de um fogão solar para cocção de alimentos com parábola refletora fabricada em compósito que utiliza fibras de Carnaúba e resina Ortoftálica

Presents a composite formed by orthophthalic resin and fiber loading of carnauba straw. The fibers were first dried in direct sun exposure and subsequently ground into fodder for the reduction in size. Various formulations of the composite were preliminarily tested by choosing the one presenting the best processability in applying the mold. The composite produced is used for the manufacture of a parabolic surface subsequently coated with mirror segments, flexible plastic, for reflecting the solar rays incident on it. The reflective parable represents the main element of the solar cooker that works with the concentration of sunlight and has dimensions of 1.14 m in diameter and area of 1.0 m². Manufacturing processes and assembly of solar cooker concentration produced are presented. The results of tests for cooking and baking various foods, including rice, pasta, beans, cake, cassava, shrimp, beef, breaded demonstrating the competitiveness of solar cooker studied with other stoves already manufactured and tested in Brazil are presented and in the world. It was also demonstrated the feasibility of the proposed composite for Prototypes manufacture of solar and other structures that do not require great efforts resistance

Estudo da viabilidade da destilação solar para polimento de águas produzidas de petróleo

This work study of solar distillation feasibility in effluent of petroleum industry: produced water, making possible your reuse for irrigation of oleaginous cultures or fodder crops or in steam generation, as well the transport phenomena involved. The methodology for development of this project was to characterize the effluent to be treated and to accomplish physical and chemical analysis in the distilled, to build distillation equipment, concomitant operation of both equipments and implementation of data processing and economical evaluation. The methodology used for all parameters is outlined in APHA (1998) and sampling of the type compound. The feeding of distillation equipment was performed with treated effluent from UTPF of Guamaré. The temperature was monitored throughout the distillers and during the time of operation. The distillers feed occur, as a rule, for sifon. The distillers were operated by a period of 17 months between July 2007 and February 2009, in which 40 experiments were performed. The radiation and temperature datas were acquired in the INPE s site and the temperature inside of the distillers was registered by DATALOGGER Novus. The rates of condensation (mL / min) were determined by measuring of the flow in a graduate test tube of 10 mL and a chronometer. We used two simple solar effect distillers of passive type with different angles in coverage: 20 ° and 45 °. The results obtained in this study and the relevant discussions are divided into six topics: sample characterization and quality of distilled; construction of distillers; operation (data, temperature profile), climatic aspects, treatment of data and economical analysis. Results obtained can be inferred that: the energy loss by the adoption of vessel glass was not significant, however, complicates the logistics of maintenance the equipment on a large scale. In the other hand, the surface of the tub with a glass shield on the equipment deterioration, both devices showed similar performance, so there is not justified for use of equipment 450. With regard to the climatological study it was verified that the Natal city presents monthly medium radiation varying in a range between 350 and 600 W/m2, and medium of wind speed of 5 m / s. The medium humidity is around 70% and rainfall is very small. The regime of the system is transient and although it has been treated as a stationary system shows that the model accurately represents the distillers system's 20 degrees. The quality of the distilled with regard to the parameters evaluated in this study is consistent with the Class 3 waters of CONAMA (Resolution 357). Therefore we can conclude that solar distillation has viability for treat oilfield produced water when considered the technical and environmental aspects, although it is not economically viable

Fatores associados à condição de saúde bucal de pacientes internados em hospitais públicos do município de Natal-RN

The hospitalization is an event that can attack any person, independent of gender, race, social and economical condition. Last year, the prevalence of hospitalization was 8.1 for 100 inhabitants and the average time of hospitalization was 8.5 days for each patient one in Natal city. Therefore, an important point is whether the attention to the patients during the permanence in these health establishments incorporates the health integral model suggested by the principles proposed by the National Health System in Brazil (SUS), with actions of promotion and protection by different kinds of professionals, beside those called convalescence. Then, the aim of this study was to evaluate the patient s oral health conditions hosted in public hospitals of the Natal city, looking for to establish its relationship with several risk factors by two dimensions: the characteristics of the hospitalization and the patient s general and economical conditions. We accomplished a cross-sectional study with 205 patients distributed among the hospitals Onofre Lopes, Giselda Trigueiro and Monsenhor Walfredo Gurgel, looking for to know the socio-demographic characteristics, the food habits and of oral hygiene and the conditions of oral health, through the Visible Plaque Index and Gingival Bleeding Index. We observed that the conditions of the patient s oral health interned at public hospitals of reference of the municipal district of Natal is bad, existing accumulation of dental plaque and, consequently, a great number of patients with gingival bleeding. However, the time of hospitalization and its reason, the type of medicine used in this time and the toothbrush frequency were not configured as risk factors for this oral health condition

Detecção de bactérias periodontopatogênicas cultiváveis e não cultiváveis em placas ateromatosas

Periodontal infections consist of a group of inflammatory conditions caused by microorganisms that colonize the tooth surface through the formation of dental biofilm. Chronic infections such as periodontitis have been associated to the development and progression of atherosclerosis. AIM: Detect cultivatable and non-cultivatable periodontopathogenic bacteria in atheromatous plaques; search for factors associated to the presence of these bacteria in the atheromatous plaques and characterize the presence of cultivatable and non-cultivatable bacteria in these plaques. METHODOLOGY: A cross-sectional study was performed with a sample of 30 patients diagnosed with atherosclerosis in the carotid, coronary or femoral arteries and surgically treated with angioplasty and stent implant, bypass or endarterectomy. The plaques were collected during surgery and analyzed using the PCR molecular technique for the presence of the DNA of the cultivatable bacteria Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Treponema denticola and of the non-cultivatable Synergistes phylotypes. The patients were examined in the infirmary, after the surgery, where they also responded to a questionnaire aimed at determining factors associated to the presence of periodontopathogenic bacteria in the atheromatous plaques. RESULTS: All patients with tooth (66,7%) possessed disease periodontal, being 95% severe and 65% widespread. No periodontopathogenic bacteria were found in the atheromatous plaques. However, four samples (13.3%) were positive for the presence of bacteria. Of these, three participants were dentate, being two carriers of widespread severe chronic periodontite and one of located severe chronic periodontitis. None of them told the accomplishment of procedures associated to possible bacteremia episodes, as treatment endodontic, extraction the last six months or some procedure surgical dental. CONCLUSION: The periodontopathogenic bacteria studied were not found in the atheromatous plaques, making it impossible to establish the prevalence of these pathogens or the factors associated to their presence in plaques, the detection of positive samples for bacteria suggests that other periodontal and non-periodontal pathogens be studied in an attempt at discovering the association or not between periodontal disease and/or others infections and atherosclerosis, from the presence of these bacteria in atheromas

Avaliação clínica da relação entre o índice de placa, índice gengival, alinhamento dental, mucosa ceratinizada, tipo de periodonto e distúrbios oclusais com a ocorrência de recessão gengival

This study clinically evaluated the relationship of gingival recessions with the periodontal index of gingival and plaque, dental alignment, keratinized mocous, type of periodontal, and occlusal disorders. Study participants were individuals aged between 19 and 33 years. The evaluations were performed by using questionnaires and clinical examinations. In subjects examined, the teeth were assessed and divided into groups (Molars, premolars, canines and incisors). The gingival recession were measured in the central region of the teeth and individuals were subject to disclosure to the plate and observing the poll of plaque and gingival index, respectively. 558 teeth were examined, with 24.1%, 135 had gingival recession greater than or equal to 1mm. Through the combination of tests used to evaluate the average of the recession and its relationship with the variables studied, we observed that the degree of recession of the elements assessed dental showed, almost for the most part, when higher values associated with the index plaque (p = 0.101), Gingival Index (p = 0.053), dental alignment (p = 0.962), width of keratinized mocous (p = 0.004) and type of periodontium (p = 0.033), however statistically significant difference could only be considered when related the recessions in the keratinized mocous and the type of the periodontium. Although we identify, when we evaluate the whole set of teeth that occlusal disturbances (p = 0.002) were more strongly associated with cases of gum recession that the gingival index (p = 0.006), however, these two conditions were correlated with the cases of recession, contributing to its occurrence

Avaliação de lesões brancas de cáries: um estudo de prognóstico

Objective: The aim of the present study is to assess the current situation of white enamel lesions on vestibular surfaces of permanent upper incisors, diagnosed 6 years ago, without clinical intervention. Methods: A prospective study reassessed 53 students of both sexes, aged between 13 and 18 years old, all attending the public school system in Natal, Brazil. Data collection was performed by duly calibrated examiners, and a clinical chart consisting of demographic data on dental caries, oral hygiene, and gingival condition was prepared. A tactile-visual examination was conducted using a clinical mirror and periodontal probe. Data compilation and analysis were carried out using a SPSS software. In this analysis the chi-squared test was used for qualitative independent variables. To identify the net effect of treatment, multiple logistic analysis with forward stepwise model selection was performed. Results: The final sample was composed of 106 lesions in the 53 individuals, with mean age of 15.02 years, visible plaque index (VPI) of 23.34%, and gingival blood indices (GBI) of 25.92%. A statistically significant relationship (p = 0.003) was found between initial DMFS and prognosis of white enamel lesion. Conclusions: We observed that past caries experience and dental plaque were the main predictive factors for negative lesion outcomes, demonstrating the need for oral hygiene control through continuing preventive measures

Validação de um método auxiliar de diagnóstico como preditivo da presença de cárie de dentina em dentes decíduos

Esse estudo se propôs a avaliar um método auxiliar de diagnóstico (DIAGNOdent®) na predição de cárie de dentina em dentes decíduos, através de validação histológica e de microdureza. Verificando possíveis diferenças entre os valores obtidos através do método auxiliar, além de determinar um ponto de corte para parada de remoção de tecido cariado. A amostra do estudo foi de 15 crianças que apresentaram 21 cavidades de cárie, tratadas e analisadas desde antes da realização da restauração até quando da exodontia do elemento dentário. Os espécimes foram analisados através do DIAGNOdent® antes da abertura das cavidades, após a remoção do tecido cariado e depois da reabertura das cavidades que se deu após a exodontia dos elementos dentários. Posteriormente, receberam preparo metalográfico para realização de testes de microdureza e microscopia óptica que serviram como forma de validação para as mensurações obtidas pela fluorescência a laser. Houve diferença significativa entre os valores DIAGNOdent® encontrados antes da abertura da cavidade e os demais (p < 0,0001). Havendo correlação significativa (r = 0,432 ; p = 0,019) apenas para as aferições obtidas antes da abertura das cavidades e quando do término da remoção do tecido cariado. Para a microdureza, as médias axiais foram significativamente maiores que as pulpares, existindo correlação entre a microdureza pulpar e os valores do DIAGNOdent® após a reabertura (r = - 0,472 ; p = 0,002). Valores de 15,38% para a sensibilidade, 100% para a especificidade, 100% para o valor preditivo positivo e 71,79% para o valor preditivo negativo, foram obtidos quando se utilizou um ponto de corte de 30 para fluorescência a laser, tendo como padrão-ouro a microdureza pulpar. Partindo da média dos valores de fluorescência a laser obtidos após a remoção do tecido cariado e acrescentando-se um desvio-padrão a esta, o método indicou o valor de 19 como ponto de corte para cessar a remoção de dentina. Concluiu-se que, nas condições analisadas, o método auxiliar de diagnóstico (DIAGNOdent®) é um método acurado na predição de cárie de dentina em dentes decíduos. Além disso, o método comprovou que o padrão usual de remoção de dentina garante a remoção do tecido cariado