143 resultados para Localização de falhas (Engenharia)


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Electrical Submersible Pumping is an artificial lift method for oil wells employed in onshore and offshore areas. The economic revenue of the petroleum production in a well depends on the oil flow and the availability of lifting equipment. The fewer the failures, the lower the revenue shortfall and costs to repair it. The frequency with which failures occur depends on the operating conditions to which the pumps are submitted. In high-productivity offshore wells monitoring is done by operators with engineering support 24h/day, which is not economically viable for the land areas. In this context, the automation of onshore wells has clear economic advantages. This work proposes a system capable of automatically control the operation of electrical submersible pumps, installed in oil wells, by an adjustment at the electric motor rotation based on signals provided by sensors installed on the surface and subsurface, keeping the pump operating within the recommended range, closest to the well s potential. Techniques are developed to estimate unmeasured variables, enabling the automation of wells that do not have all the required sensors. The automatic adjustment, according to an algorithm that runs on a programmable logic controller maintains the flow and submergence within acceptable parameters avoiding undesirable operating conditions, as the gas interference and high engine temperature, without need to resort to stopping the engine, which would reduce the its useful life. The control strategy described, based on modeling of physical phenomena and operational experience reported in literature, is materialized in terms of a fuzzy controller based on rules, and all generated information can be accompanied by a supervisory system

Relevância:

20.00% 20.00%

Publicador:

Resumo:

To aureus α-HL channel, we used the cysteine-scanning mutagenesis technique. Twenty-four mutants were produced from the substitution of a single aminoacid of the primary structure of the α-HL pro this yzed after the incorporation of a mutant channel in planar lipid bilayer membranes. The modified proteins were studied in the absence and presence of watersoluble specific sulphydryl-specific reagents, in order to introduce a strong positive or negative harge at positions of substitution. The introduction of a negative charge in the stem region onverted the selectivity of the channel from weak anionic to more cationic. However, the troduction of a positive charge increased its selectivity to the anion. The degree of these alterations was inversely dependent on the channel radius at the position of the introduced harge (selectivity). As to the asymmetry of the conductance-voltage, the influence of the harge was more complex. The introduction of the negative charge in the stem region (the trans art of the pore) provoked a decrease. The intensity of these alterations depended on the radius, and on the type of free charge at the pore entrance. These results suggest that the free charge at surrounds the pore wall is responsible for the cation-anion selectivity of the channel. The istribution of the charges between the entrances is crucial for determining the asymmetry of e conductance-voltage curves. We hope that these results serve as a model for studies with other nanometric channels, in biological or planar lipid bilayer membranes or in iotechnological applications

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of the present study was to assess the effectiveness and adverse effects on dental enamel caused by nightguard vital bleaching with 10% carbamide peroxide. This was accomplished through the interaction of researchers from different areas such as dentistry, materials engineering and physics. Fifty volunteers took part in the doubleblind randomized controlled clinical trial. They were allocated to an experimental group that used Opalescence PF 10% (OPA) and a control group that used a placebo gel (PLA). Fragments of human dental enamel from the vestibular surface of healthy premolars, extracted for orthodontic reasons, were fixed to the vestibular surface of the first upper molars of the volunteers for in situ observation. Bleaching was performed at night for 21 days. The observation periods included Baseline (BL), T0 (21 days), T30 (30 days after treatment) and T180 (180 days after treatment, only for the OPA group). Tooth color was assessed by comparing it with the Vita® scale and by the degree of satisfaction expressed by the volunteer. We also assessed adverse clinical effects, dental sensitivity and gingival bleeding. The study of adverse effects on enamel was conducted in vivo and in situ, using the DIAGNOdent® laser fluorescence device to detect mineral loss. Scanning electron microscopy (SEM) was used to check for superficial morphological alterations, energy dispersive spectrophotometry (EDS) to semiquantitatively assess chemical composition using the Ca/P ratio, and the x-ray diffraction (XRD) technique to observe alterations in enamel microstructure. The results showed that nightguard vital bleaching with 10% carbamide peroxide was effective in 96% of the cases, versus 8% for the PLA group. Dental sensitivity was present in 36% (9/25) of the cases. There was no significant association between gingival bleeding and the type of gel used (p = 1.00). In vivo laser fluorescence analysis showed no difference in values for the control group, whereas in the OPA group there was a statistically significant difference between baseline values in relation to the subsequent periods (p<0.01), with lower mean values for post-bleaching times. There was a significant difference between the groups for times T0 and T30. Micrographic analysis showed no enamel surface alterations related to the treatment performed. No significant alteration in Ca/P ratio was observed in the OPA group (p = 0.624) or in the PLA group (p = 0.462) for each of the observation periods, nor between the groups studied (p=0.102). The XRD pattern for both groups showed the presence of three-phase Hydroxyapatite according to JCPDS files (9-0432[Ca5(PO4)3(OH)], 18-0303[Ca3(PO4)2.xH2O] and 25-0166[Ca5(PO4)3(OH, Cl, F)]). No other peak associated to other phases was found, independent of the group analyzed, which reveals there was no disappearance, nucleation or phase transformation. Neither was there any alteration in peak pattern location. With the methodology and protocol used in this study, nightguard vital bleaching with 10% carbamide peroxide proved to be an effective and safe procedure for dental enamel

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis deals with the factors affecting customer satisfaction and loyalty in the supermarket sector. It is adapted a model proposed by Johnson et al. (2001) and included the brand construct as a loyalty of construct antecedent. It is conducted a survey with a sample of 290 customers of a supermarket in Natal city, Brazil, and descriptive and multiple regression statistical analysis. The main findings are that the proposed model is confirmed with quality being the main factor affecting satisfaction, but also in this case the place marketing construct playing a key role on satisfaction. The loyalty model is also supported by this research with the brand construct appearing important for a segment of the customers. This study support the conclusion that customer satisfaction is not the sole or main factor to explain loyalty

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The quarrel on the urban intensific use of determined areas of the city is carried through in some levels of the society, which had to the fact to bring direct influences the population that inhabits it. The question to become an area to intensific use, implies in determining that the local infrastructure has the capacity to take care of to a bigger amount of people, inhabitants or passers-by. In the quarter of Ponta Negra, in Natal city (state of RN), its condition of area to intensific use to the municipal Law 27/2000 happened due that it starts to allow a bigger level of occupation of part of the quarter. This law has a direct relation with the installation of a complementary infrastructure in the quarter, to put does not send to its complementation and maintenance, what it takes the consequences that are felt by the population. This work has as main objective the identification of the decurrent significant consequences of the creation of Ponta Negra s Intensific Use Zone, according to vision of the population of the quarter. The way followed for this involves the compatible bibliography research with the subject, analysis of documents that treat on the quarter, mappings of the area in search of a physical characterization and mainly, an application of questionnaire next to local population. In this questionnaire it is the main point of the necessary collection of data to the work, indicating the point of view of the population not only on the negative points, but also on the positive points that had happened since the creation of Intensific Use Zone. The answers indicate problems of natures social, infrastructure and enviromental, compatible with the problems of other areas that had passed the same for process, as point the studied bibliography, indicating imperfections in the planning process and maintenance of Ponta Negra s Intensific Use Zone

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis deals with the factors affecting customer satisfaction, loyalty and recommendation in the health care sector. It is adapted a model proposed by Johnson et al. (2001) of quality and loyalty antecedent factors and it is conducted a survey with a sample of 109 customers of a hospital on the ambulatory in Natal city, a capital of a Northeastern State of Brazil. It is carried descriptive and multiple regression statistical analysis. The main findings related to satisfaction are that quality factors of doctor professionalism, clerical staff efficiency, consultancy room comfort, time to provide the medical consultancy but also hospital localization are the most significant factors affecting satisfaction. Regarding personal full loyalty, satisfaction with the hospital and affective commitment are the main factors yet for partial loyalty image and calculate commitment play the main role. For recommendation satisfaction, image and brand are the main factors. The overall model used fairly explains the satisfaction, loyalty and recommendation outcomes with varying factors regarding each final purpose, e.g. loyalty or recommendation

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The decrease in crime is one of the core issues that cause concern in society today. This study aims to propose improvements to public safety from the choice of points to the location of police units, ie the points which support the car and the police. For this, three models were developed in order to assist decision making regarding the best placement of these bases. The Model of Police Units Routing has the intention to analyze the current configuration of a given region and develop optimal routes for round preventative. The Model of Allocation and Routing for New Police Units (MARNUP) used the model of facility location called p-median weighted and traveling salesman problem (TSP) combined aiming an ideal setting for regions that do not yet have support points or to assess how far the distribution is present in relation to that found in solution. The Model Redefinition and Routing Unit Police (MRRUP) seek to change the current positioning taking into account the budgetary constraints of the decision maker. To verify the applicability of these models we used data from 602 points to instances of police command that is responsible for the capital city of Natal. The city currently has 31 police units for 36 of these 19 districts and police have some assistance. This reality can lead to higher costs and higher response times for answering emergency calls. The results of the models showed that in an ideal situation it is possible to define a distance of 500 km/round, whereas in this 900 km are covered by approximately round. However, a change from three-point lead reduced to 700 km / round which represents a decrease of 22% in the route. This reduction should help improve response time to emergency care, improving the level of service provided by the increase of solved cases, reducing police shifts and routing preventive patrols

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work focuses on the relationship between organizational culture and quality culture in the hotel sector of NATAL/RN with respect to employee performance. The themes organizational culture and quality have been the research focus of administration theorists and a constant concern of professional managers, since the Japanese demonstrated effective forms or western management. In this study, the Competing Values Model (C.V.M.) (Quinn e Cameron, 1996; Quinn, 1998; Santos, 1998, 2000; Teixeira, 2001), which was tested on north-American organizations and considered a high value academic and professional instrument, was applied. The model maps the organizational culture on a profile with four elements: clan, adhocracy, market and hierarchy. The C.V.M., associated with the taximetrics created by Cameron (which classifies quality culture in for levels: status quo, error detection, error prevention and perpetual creative quality) has been related with organizational performance. In this study, these two models are used jointly and tested in the hotel sector. The results indicate that the strongest element of the profile is clan, which is characterized by internal focus, participation and people involvement, followed by the adhocracy element, which has an external focus, emphasizes flexibility and is characterized by dynamic enterprising and creativity. Regarding the level of the culture s quality in the hotel, the highest level, that of perpetual improvement and creativity, which attempts to enchant and to surprise the clients, was most frequently cited, followed by the error detection level, which has as its goal to discover and correct mistakes, trying, consequently, to reduce waste. The results suggest that employee performance as measured on some indicators is related to elements of the organizational culture profile and quality level

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The changes that have taken place in the organizational environment in recent decades have led to new performance measurement systems being proposed, given the inadequacy of traditional models. The Balanced Scorecard (BSC) emerged as an instrument to translate financial and non-financial assets into real values for all interested parties in the organization, allowing the introduction of strategies to achieve the desired goals. Research shows that most errors committed with the use of this method are related to the implementation process. Thus, the aim of this dissertation is to analyze the process of building and implementing the BSC in an organization. This empirical exploratory study is based on the classic case study method, which enables the researcher to work with a set of evidence, including direct observation, interviews and document analysis. The results show that the use of BSC in the company investigated posed problems during the process of building and implementing the method. These problems were caused mainly by the lack of involvement on the part of upper management and the team s scant knowledge of Balanced Scorecard. One of the gains obtained from adopting the system was the introduction and/or consolidation of a culture of strategic planning and participative management. The continuous implementation phase was highlighted in the monitoring program, created by the organization in an attempt to reverse existing problems, using the BSC as a third generation strategic management system, which led to significant gains, better use of the system and stronger management practices

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A presente dissertação representa uma contribuição na resolução dos problemas que se apresentam no setor das indústrias de cerâmica vermelha, apresentamos um modelo, baseado na estratégia do QFD (Desdobramento da Função Qualidade), na qual associa os requisitos dos consumidores na elaboração dos projetos do produto e dos processos de produção. A qualidade do produto é avaliada tanto no aspecto interno(especificações técnicas) quanto no aspecto externo (qualidades exigidas pelos clientes). A pesquisa mostra, além da realidade que vive o setor das indústrias de cerâmica, a importância e os atributos da qualidade definidos pelos consumidores relativo aos tijolos cerâmicos de vedação. O trabalho também mostra os resultados da aplicação do modelo numa das empresas do setor, através de desdobramentos da qualidade exigida, se estabelece a qualidade planejada, mostra ainda a posição da empresa em relação aos concorrentes em função do desempenho do produto. Procura-se ainda, através de sugestões de melhorias, atacar os problemas das falhas na qual geram o desperdício

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work searches to offer a model to improve spare parts stock management for companies of urban passenger transport by bus, with the consequent progress in their maintenance management. Also known as MRO items (Maintenance, Repair and Operations), these spare parts, according their consumption and demand features, cost, criticity to operation, lead-time, quantity of suppliers, among other parameters, shouldn´t have managed their inventory like normal production items (work in process e final products), that because their features, are managed by more predictable models based, for example, in economic order quantity. In the case specifically of companies of urban passenger transport by bus, items MRO have significant importance in their assets and a bad management of these inventories can cause serious losses to company, leading it even bankrupticy business, in more severe situations which missing spare part provokes vehicles shutdown indefinitely. Given slight attention to the issue, which translates in little literature available about it when compared to that literature about normal items stocks, and due the fact that MRO items be critical to bus urban transport of passengers companies´, it is necessary, so, deepen in this theme searching to give technical and scientific subsidies to companies that work, in many times, empirically, with these so decisive inputs to their business. As a typical portfolio problem, in which there are n items, separated into critical and noncritical, while competing for the same resource, it was developed a new algorithm to aid in a better inventory management of spare parts used only in corrective maintenance (whose failures are unpredictable and random), by analyzing the cost-benefit ratio, which compares the level of service versus cost of each item. The model was tested in a company of urban passenger transport by bus from the city of Natal, who anonymously provided their real data to application in this work

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The research aimed identify how the quality of services provided by Casa de Apoio à Criança com Câncer Durval Paiva is perceived by its users, giving an opportunity of improve their performance in social services provision pointing out the failures experienced, the institution will have the user as a important partner in fails identification, serving as a subsidy to the actions of correction and improvement to such situations demands. With this work implementation will be observed contributions that will permeate to the fields of theory and practice, enabling progress and enrichment on the subject. The theoretical contribution is observed as this work execution will provide greater advance about the models developed for the third sector. The proposed work will raise awareness issues about the full potential of the social economy, with regard to the quality of services provided by organizations, allowing a better definition of priorities on their development. The study addressed three issues: identifying the people that receive support of the Casa Durval Paiva, identifying what is the level of satisfaction of families served and evaluate the services provided by Casa Durval Paiva that demand improvements in the perception of families assisted. Found a demand for services has been found that the institution has a multidisciplinary team with a high level of professionalism, and supervised with students of various educational institutions and many volunteers to complement the actions of individual professionals. Was measured a high satisfaction of users of the services provided by Casa Durval Paiva

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The purpose of this dissertation is to formulate guidelines for the improvement of maturity models, or the development of new ones, aiming at its application to project departments. The maturity of project management has become critical for organizations that develop projects and want to stand out in the market they serve. For this purpose, maturity models provide paths in order to guarantee that the institutionalization of project management is achieved in the best possible way. Generally, these models assess the organization, define its current situation in managing projects and propose steps to be performed in the search of more advanced levels of maturity. With the objective of contributing to the improvement of maturity models for specific cases, a bibliographical research was conducted for the preparation of a comparative analysis matrix and performed a case study for application of two maturity models (MMGP and PMMM levels 2 and 3), selected based on criteria found in the literature, in an engineering department of an oil company. The case study supported the realization of a comparative analysis of models, from which guidelines were formulated for improvement. The results showed that thedepartment is evaluated in a medium stage of maturity, recording significant progress in some dimensions assessed. They also found that the results of applying the two models are presented as complementary, although the model is highlighted by the greater depth of MMGP diagnostic, considering many variables in their levels of maturity than model PMMM (levels 2 and 3).Finally, directions have been formulated that contribute to the improvement of maturity models, taking in account the organizational environment in which this work was developed

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis aims at analyzing the perspective of graduates perceived quality of an undergraduate course in order to contribute to continuous improvement. In order to achieve the proposed objectives, we performed a literature search, seeking together the work surrounding this issue, with the intent to update the concepts discussed today on the subject studied, they are: quality management, quality in higher education institutions and the system national assessment of higher education - Sinaes. The methodology is characterized as a case study, quantitative, and the object of study is composed of students who graduated from Production Engineering, Federal University of Rio Grande do Norte, which includes students who graduated from 2002 to 2010; data collection was done through the survey instrument, questionnaire, available online through SurveyMonkey interface, data analysis was done by means of descriptive statistics and multivariate analysis, including factor analysis. The proposed survey instrument consists of questions nineteen and twenty statements that address the central theme of this dissertation. The results show the identification of four latent factors (obtained by exploratory factor analysis), through two perspectives, the analysis of perception and importance, the results were similar in terms of the variable factors. The first factor was related to the support given to students, a factor known to support two extra class, the third factor related aspects of the library, and finalizing the evaluation and approached a factor of 4 facilities. Through research it was concluded that this study presents several points to be improved by the management team, and recommended to continue to evaluate the perceptions of graduates, seeking continuous improvement in service delivery by the university

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior