Representações espectrais de sistemas complexos: aplicações à síntese de superfícies brownianas fracionárias anisotrópicas, filtragem de sinais e identificação de correlações

In this thesis, we study the application of spectral representations to the solution of problems in seismic exploration, the synthesis of fractal surfaces and the identification of correlations between one-dimensional signals. We apply a new approach, called Wavelet Coherency, to the study of stratigraphic correlation in well log signals, as an attempt to identify layers from the same geological formation, showing that the representation in wavelet space, with introduction of scale domain, can facilitate the process of comparing patterns in geophysical signals. We have introduced a new model for the generation of anisotropic fractional brownian surfaces based on curvelet transform, a new multiscale tool which can be seen as a generalization of the wavelet transform to include the direction component in multidimensional spaces. We have tested our model with a modified version of the Directional Average Method (DAM) to evaluate the anisotropy of fractional brownian surfaces. We also used the directional behavior of the curvelets to attack an important problem in seismic exploration: the atenuation of the ground roll, present in seismograms as a result of surface Rayleigh waves. The techniques employed are effective, leading to sparse representation of the signals, and, consequently, to good resolutions

Modificação de superfícies de titânio tratadas por plasma de Ar + N2 + O2 visando aplicações biomédicas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES

Estudo das características físico-químicas e biológicas pela adesão de osteoblastos em superfícies de titânio modificadas pela nitretação em plasma

SILVA, J. S. P. Estudo das características físico-químicas e biológicas pela adesão de osteoblastos em superfícies de titânio modificadas pela nitretação em plasma. 2008. 119 f. Tese (Doutorado) - Faculdade de Medicina, Universidade de São Paulo. São Paulo, 2008.

Fatores de sucesso na implementação de sistemas integrados de gestão empresarial (ERP): estudo de caso em uma média empresa

RAMOS, A. S. M.; OLIVEIRA, M. A. Fatores de sucesso na implementação de sistemas integrados de gestão empresarial (ERP): estudo de caso em uma média empresa. In: ENCONTRO NACIONAL DE ENGENHARIA DE PRODUÇÂO, 22., 2002, Curitiba-PR. Anais... Porto Alegre-RS: ABEPRO, 2002. v. 1.

Avaliação do estresse oxidativo induzido por superfícies de titânio

Commercially pure Titanium (cp Ti) is a material largely used in orthopedic and dental implants due to its biocompatibility properties. Changes in the surface of cp Ti can determine the functional response of the cells such as facilitating implant fixation and stabilization, and increased roughness of the surface has been shown to improve adhesion and cellular proliferation. Various surface modification methods have been developed to increase roughness, such as mechanical, chemical, electrochemical and plasma treatment. An argon plasma treatment generates a surface that has good mechanical proprieties without chemical composition modification. Besides the topography, biological responses to the implant contribute significantly to its success. Oxidative stress induced by the biomaterials is considered one of the major causes of implant failure. For this reason the oxidative potential of titanium surfaces subjected to plasma treatment was evaluated on this work. CHO-k1 cells were cultivated on smooth or roughed Ti disks, and after three days, the redox balance was investigated measuring reactive oxygen species (ROS) generation, total antioxidant capacity and biomarkers of ROS attack. The results showed cells grown on titanium surfaces are subjected to intracellular oxidative stress due to hydrogen peroxide generation. Titanium discs subjected to the plasma treatment induced less oxidative stress than the untreated ones, which resulted in improved cellular ability. Our data suggest that plasma treated titanium may be a more biocompatible biomaterial.

Desenvolvimento de um protótipo para análise dinâmica da dureza de superfícies metálicas

In this paper we developed a prototype for dynamic and quantitative analysis of the hardness of metal surfaces by penetration tests. It consists of a micro-indenter which is driven by a gear system driven by three-rectified. The sample to be tested is placed on a table that contains a load cell that measures the deformation in the sample during the penetration of micro-indenter. With this prototype it is possible to measure the elastic deformation of the material obtained by calculating the depth of penetration in the sample from the difference of turns between the start of load application to the application of the load test and return the indenter until the complete termination of load application. To determine the hardness was used to measure the depth of plastic deformation. We used 7 types of steel trade to test the apparatus. There was a dispersion of less than 10% for five measurements made on each sample and a good agreement with the values of firmness provided by the manufacturers.

Propriedades tribomecânicas de superfícies de titânio carbonitretadas por plasma

Interstitial compounds of titanium have been mainly studied due to the large range of properties acquired when C, N, O and H atoms are added. In this work, surfaces of TiCxNy were produced by thermochemical treatments assisted by plasma with different proportions of Ar + N2 + CH4 gas mixture. The Ar gas flow was fixed in 4 sccm, varying only N2 and CH4 gas flows. During the thermochemical treatment, the plasma was monitored by Optical Emission Spectroscopy (OES) for the investigation of the influence of active species. After treatments, C and N concentration profile, crystalline and amorphous phases were analyzed by Nuclear Reaction (NRA). Besides tribomechanical properties of the Ti surface were studied through the nanohardness measurements and friction coefficient determination. The worn areas were evaluated by profilometry and Scanning Electronic Microscope (SEM) in order to verify the wear mechanism present in each material. It has been seen which the properties like nanohardness and friction coefficient have strong relation with luminous intensity of species of the plasma, suggesting a using of this characteristic as a parameter of process

Influência das espécies do plasma de N2 + O2 nas propriedades físicoquímicas das superfícies do pet

This work reports the influence of the poly (ethylene terephthalate) textile and films surface modification by plasmas of O2 and mixtures (N2 + O2), on their physical and chemical properties. The plasma surface polymeric modification has been used for many researchs, because it does not affect the environment with toxic agents, the alterations remains only at nanometric layers and this technique shows expressive results. Then, due to its good acceptance, the treatment was carried out in a vacuum chamber. Some parameters remained constant during all treatment, such as: Voltage 470 V; Pressure 1,250 Mbar; Current: 0, 10 A and gas flow: 10 cm3/min, using oxygen plasma alternating the treatment time 10 to 60 min with an increase of 10 min to each subsequent treatment. Also, the samples were treated with a gas mixture (nitrogen + oxygen) which was varied only the gas composition from 0 to 100% leaving the treatment time remaining constant to all treatment (10 min). The plasma treatment was characterized in-situ with Optics Emission Spectroscopy (OES), and the samples was characterized by contact angle, surface tension, Through Capillary tests, Raman spectroscopy, Infrared attenuated total reflection (IR-ATR) and atomic force microscopy, scanning electronic Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). The results showed that oxygen treated fabrics presented high wettability, due to the hydrophilic groups incorporation onto the surface formed through spputering of carbon atoms. For the nitrogen atmosphere, there is the a film deposition of amine groups. Treatment with small oxygen concentration in the mixture with nitrogen has a higher spputered species of the samples

Caracterização de superfícies de titânio modificado por oxidação à plasma

Recent years have seen a significant growth in surface modifications in titanium implants, resulting in shorter healing times in regions with low bone density. Among the different techniques, subtraction by chemical agents to increase oxidation has been applied for surface treatment of dental implants. However, this technique is generally unable to remove undesirable oxides, formed spontaneously during machining of titanium parts, raising costs due to additional decontamination stages. In order to solve this problem, the present study used plasma as an energy source to both remove these oxides and oxidize the titanium surface. In this respect, Ti disks were treated by hollow cathode discharge, using a variable DC power supply and vacuum system. Samples were previously submitted to a cleaning process using an atmosphere of Ar, H2 and a mixture of both, for 20 and 60 min. The most efficient cleaning condition was used for oxidation in a mixture of argon (60%) and oxygen (40%) until reaching a pressure of 2.2 mbar for 60 min at 500°C. Surfaces were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), adhesion and cell proliferation. SEM showed less cell spreading and a larger number of projections orfilopodia in the treated samples compared to the control sample. AFM revealed surface defects in the treated samples, with varied geometry between peaks and valleys. Biological assays showed no significant difference in cell adhesion between treated surfaces and the control. With respect to cell proliferation, the treated surface exhibited improved performance when compared to the control sample. We concluded that the process was efficient in removing primary oxides as well as in oxidizing titanium surfaces

Superfícies de titânio modificadas termoquimicamente por plasma : avaliação da resposta biológica

This laboratory study involves the participation of a group with professionals from different areas that had contributed to the construction of a multidisciplinary knowledge, about biological response of titanium surfaces modified through thermochemical treatment by plasma. Thus, the crystalline phase was previously characterized in relation to the topography, roughness, molhability and nitrogen concentration in the samples surface. It s indispensable that materials implanted can influence in a good cellular response as well as promotes a bacteria action. Surfaces modified by plasma were exposed to different cultures such as: cellular (human osteoblastic) and bacteria (Staphylococcus epidermidis ATCC35984 and Pseudomonas aeruginosa ATCC 27853) in order to evaluate the biological response. It was evaluated the adhesion, proliferation, morphology and cellular preference of human ostheoblastic cells (HOST), as well as the formation of a biofilm and bacteria proliferation. It was still analyzed the bacteria selectivity ability in relation to the surfaces. The software Image Pro Plus was used to the counting of cells and bacteria adhered to the surface of disks. The results were submitted to the variance analysis (ANOVA), and then, by the Kruskal-Wallis test, using GraphPad Instat ® software, version 3.5 to Windows. The nitrided samples in spite of show a higher roughness and molhability showed a smaller bacteria growing and higher cellular proliferation, when compared to non treated samples, indicating that the treated material present a high efficiency to biomedical implants

Violência, mídia e juventude: análise sobre o discurso adotado pelo jornalismo impresso sobre a realidade violenta de jovens da periferia da cidade do Natal

The work that follows has as its main objective the analysis of the discourse of media, with emphasis on newspapers printed on acts and events involving young offenders. The speech adopted by columnists of newspapers, based on formulas and journalistic practices exist, allows the reader a view of what happened in detail. But this wealth of information, contradictorily, it seems not permit, much less to encourage reflection on the what is being read. All information contained in narrative journalism seem to point to the establishment of maintenance of speech reinante of violence and repression against young offenders, from, and generally in the vast majority of cases, from poor neighborhoods and suburbs of large cities. The whole range of such important issues directly related to violence committed by these young people does not appear, does not appear in the text journalism. Words such as "marginal", "square" reinforce prejudices, stigmas against the youth, putting the company on constant alert against such "criminals", "malandros." The result of the survey was partial, but can conclude about the importance of the media against those social phenomena that amedrontam the society at present

A mídia impressa sergipana nas eleições para governador em 2006: cobertura do Cinform, correio de Sergipe e jornal da cidade

The elections for governor in 2006 with its victory Marcelo Déda Workers Party (PT), were a landmark in the state of Sergipe, for the first time, called progressive fronts (an alliance of parties formed mostly by origin of the left) broke the hegemony of two political groups, Franco and the Alves, whose direction was in force for over 30 years. This study proceeds on the assumption that the print media has certain standards of conduct in covering the election period. Therefore, this study seeks to quantify, classify and compare data from three newspapers more representative of the State of Sergipe (Cinform, Cidade Journal and Correio de Sergipe) to analyze the behavior of these journals, such as private apparatus of hegemony in election coverage 2006. It also uses the concept of hegemony Gramsci and theories of journalism framing (Entman and Porto) and agenda setting (McCombs and Shaw) to identify these patterns

Imagens do medo na mídia: uma análise das representações da violência em Natal-RN

Social violence is one of the phenomena of human life that produce effects on the social imaginary as it is in it that are designed conflicting values concerning what is most vital to humans, such as respect for the strength and the fear of death, pleasure trespass for injury and pain, the rejection of injustice and anger that is born of revolt. The variability of feelings and reasons that constitute violence has required academic knowledge increasingly sensitive reflections that encompass the complexity of its manifestations. The feeling of fear and insecurity which constitute the collective social imagination has caused large changes in the behavior of both individuals and the society as a whole. This study aims to reflect on media representations the social violence in Natal-RN. Through a thematic survey and documentary analysis of three newspapers of Rio Grande do Norte - Tribuna do Norte, Novo Jornal and Jornal Metropolitano - was possible to list events and trace different discursive strategies that lead to receptors ideological interests of class, constitute social and spatial segregations and maximize violations of rights and of the human dignity, with important implications in the construction of social representations concerning the reality of violence

Os crimes de mídia no paradigma democrático constitucional

The criminal responsibility of the media is analyzed when the criteria for production of news and events involving public safety are produced without considering the technical, legal and ethical practice of journalism in the media factors. Freedom of speech, expression of thought, necessary for professional qualifications and constitutional limits, reaching criminal constitutional principles and the possibilities of criminal liability for offenses practiced in the media are present as key factors legal dialogue in this work. The judgment of the Supreme Court on the unconstitutionality of Law nº. 5.250/67 called Media Law caused a gap in the national legal system, forcing the use of the criminal code to address issues that involve crimes produced in media professional performance. The presumption of innocence is ignored by the professional media during a police investigation where the information published does not respect, including constitutional guarantees: the right to privacy, honor and image. The right to information and the duty to inform media are worked in its constitutional aspect, considering that the same information should be produced is guided by the quality and guiding principles of truth. The constitutional concept of media is presented as information with the appropriate language of the news media, produced and disseminated through the vehicles of mass media, whether in print or digital platform. The presented model of the legal right to information is outlined from a constitutional hermeneutics, increasing the production of news as a result of the occupation of journalist in different news platforms, guaranteeing the quality of this prolific law. Under the Freedom of professional activity of the journalist, the constitutional limits are addressed in line with the reality of (non) regulation of their profession, considering the constitutional abuses committed in the exercise of that activity linked to communication fences. Jusphilosophic field reaches the limits of the duty of truth in journalism as a tool for spreading news, respect the audience and compatibility with the constitutional state. Using the conceptual and doctrinal aspects, this criminal offense is parsed from the journalistic practice and the publication of news involving public safety, with the hypothetical field consummation of that crime through the eventual intention. As a form of judgment against these crimes produced in honor media presents the court of the jury as a legitimate form of democratic decision

Natal como destino turístico : um estudo das imagens (re)veladas pela mídia, pelos turistas e suas implicações educacionais e culturais

This thesis is a result of a research on Natal/RN as a tourist destination. We understand that cities are chosen as tourist destinations beyond its cartographic localization, from other dimensions of meanings that, in its set, constitute images. These images are, probably, very different of the images constructed by native and resident populations, who possess relations of identity with the place. The knowledge of the meanings that others attribute to this city as tourist destination, bring us near to the symbolic bonds established by individuals or social groups on the act of their choices, as well as bring us near to the interaction process city-tourists where the expectations are confirmed or not. The images divulgated by the media also participate of the complex formation of the tourist image that is being constructed and available for the different public, in different social contexts. The tourism constitutes a symbolic asset of the modern society, being considered by the studious, as one of the most expressive phenomena of the modernity, for involving each year displacement and the interaction of thousand of people of different cultures in the entire world. All this people s mobilization points to practical social related to personal motivations, to the entailed desired to the idea to travel and to exceed borders. It is already consensus that tourism is a phenomenon of economic growth, generating jobs, income, professional, qualification, bringing improvements for the host cities. Since 1995, in Brazil, the tourism as a sector of the economy, passed to be considered one of the national priorities, and in this perspective, the national politics of the tourism invested in infrastructure of Brazilian cities with high tourist potential, objecting to increase the flows of Brazilian and foreign tourists. Owing to this fact, the country still invests in programs of tourist marketing, mainly divulging the images of the natural beauties of Brazil abroad. And for Brazilians, the campaigns appeal to rescue the feeling to be Brazilian, associating the idea to travel and know its country. Natal city possesses an excellent positioning in the tourist marketing, being predominantly divulgated in national and international level, for its naturalistic singularity, where the images of its natural enchantments as warm water beaches, white dunes, warm weather, constant breeze and an always blue sky are shown as the favorite scene on this city. From what was viewed above that the choice of a tourist destination articulates from a determined imaginary of a place, already constructed or in process of construction, we consider the knowledge of this imaginary a basic learning for the population of the city and especially, for educators, in the formation of professionals in this area and for tourism managers, elaborators of public politics. Based on this estimative, we developed this research that had as a general objective to identify the images that illustrate Natal city as a tourist destination - our objective of study, particularly the meanings and senses attributed by the tourist marketing (hotel s folders) and by the tourists that visited the city during this study. The discussions and reflections that had guided this research had been given from the theoretical link between imaginary and social representation, also considering some interfaces between the fields of communication and symbol. From the studied authors, Baczko (1985) clarifies that the study of social imaginary is directed for the mechanisms and structures of the social life, especially for the intervention accomplishes and efficient of the representations and symbols in the practical collectives, as well as in its direction and orientation . Following this same thought, Moscovici (1978) says that the social representation are produced in communicational and symbolic contexts, and these representations once that already constituted circulate socially as almost tangible entities. Based on this fundament and on the analyze of Barthes (1990), particularly in the approach given to the reading of photographic image, we could observe on hotel s folders that each page evidences senses and meanings of functionality of internal and external spaces, pointing to the way of leisure offered by the keepers of city which is the hotels. About, the leisure that they offer, it is directed to young public, giving meaning to the young myth of personalized leisure tourism on children, young and adults images. The image about security that hotels offer and the singular image of Natal city as a paradise place, provide an idealization of pleasure through the sun, dunes, and beaches and also due to the hospitability of the natives who are assigned as educated . For the tourist that participated on this research, Natal city is tied only by the imaginary of leisure and nature which constitute the emotional link of the relation media-city-tourist. And with such force and fullness of directions the city discloses without tensions and contradictions as a place protected by a mythical and sacred aura. The study also demonstrates us that the potiguar culture remains (almost) forgotten, due to the silenced in this imaginary. In this perspective, we highlight that this culture silence is very close related to the disvalue of education in its general meaning. We defend that the imaginary apprehended constitutes a new reading and a new looking and understanding the tourist reality that comes historically consolidating in this city. In this direction, we glimpse that this study and its future dismemberments can collaborate with the process of rescue the cultural values of the potiguar people, in the way that the meaning of tourist may be redefined, and the tourist image of the city can be also disclosed for its identities particularities of its culture