14 resultados para Exponential and trigonometrical octoniônic functions

em Universidade Federal do Rio Grande do Norte(UFRN)


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We investigate several diffusion equations which extend the usual one by considering the presence of nonlinear terms or a memory effect on the diffusive term. We also considered a spatial time dependent diffusion coefficient. For these equations we have obtained a new classes of solutions and studied the connection of them with the anomalous diffusion process. We start by considering a nonlinear diffusion equation with a spatial time dependent diffusion coefficient. The solutions obtained for this case generalize the usual one and can be expressed in terms of the q-exponential and q-logarithm functions present in the generalized thermostatistics context (Tsallis formalism). After, a nonlinear external force is considered. For this case the solutions can be also expressed in terms of the q-exponential and q-logarithm functions. However, by a suitable choice of the nonlinear external force, we may have an exponential behavior, suggesting a connection with standard thermostatistics. This fact reveals that these solutions may present an anomalous relaxation process and then, reach an equilibrium state of the kind Boltzmann- Gibbs. Next, we investigate a nonmarkovian linear diffusion equation that presents a kernel leading to the anomalous diffusive process. Particularly, our first choice leads to both a the usual behavior and anomalous behavior obtained through a fractionalderivative equation. The results obtained, within this context, correspond to a change in the waiting-time distribution for jumps in the formalism of random walks. These modifications had direct influence in the solutions, that turned out to be expressed in terms of the Mittag-Leffler or H of Fox functions. In this way, the second moment associated to these distributions led to an anomalous spread of the distribution, in contrast to the usual situation where one finds a linear increase with time

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Injectivity decline, which can be caused by particle retention, generally occurs during water injection or reinjection in oil fields. Several mechanisms, including straining, are responsible for particle retention and pore blocking causing formation damage and injectivity decline. Predicting formation damage and injectivity decline is essential in waterflooding projects. The Classic Model (CM), which incorporates filtration coefficients and formation damage functions, has been widely used to predict injectivity decline. However, various authors have reported significant discrepancies between Classical Model and experimental results, motivating the development of deep bed filtration models considering multiple particle retention mechanisms (Santos & Barros, 2010; SBM). In this dissertation, inverse problem solution was studied and a software for experimental data treatment was developed. Finally, experimental data were fitted using both the CM and SBM. The results showed that, depending on the formation damage function, the predictions for injectivity decline using CM and SBM models can be significantly different

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The demographic growth press environments that are more susceptible to perturbations, like riparian areas, without knowing about the effects of replacing these natural environments by different land uses on soil quality and, consequently, on watershed. The study of soil quality has evolved as an important tool for soil sustainable management of this component of the biosphere that affects aquatic and terrestrial ecosystems functions. Thus, physical and chemical soil proprieties were measured to assess soil quality under different land uses (agricultural, pasture, urban, industrial and natural vegetation,) in the riparian zone of Extremoz Lake, an important human water source, evaluating whether the soil offers potential risk to water pollution. Data were subjected to descriptive statistics and Principal Component Analysis (PCA). The results showed negative changes in soil quality such as alkalinization and increase in P, Pb, Mn and Zn contents in most anthropized areas. The sandy texture and low organic matter content in all soils showed the fragility of the soil to erosion and leaching of elements in excess to water bodies, evidencing that this soils has potential to diffuse contaminants. Conservative management of soil is necessary to provide an adequate ecological state in riparian zones of the Extremoz Lake, thus allowing controlling and buffering diffuse sources of pollution to this important water supply source

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This thesis is the result of an investigation about the transversality of the environmental issues into the daily curriculum of High Schools (from first to eighth grade). The research field was the county of Santo Antonio de Jesus in the state of Bahia, Brazil. The investigation is related with the challenge that the present model of social development and organization has put to the school institution: to bring the regular discussion about Environmental Education (EE) to the school s daily life. Facing the complexity of the socio-environmental issues and the basic functions of Education, the object of study was restricted to the identification of the challenges and paradoxes of the EE inside the curriculum organization of Politic-Pedagogic Project of the schools and the teachers daily practices. About the methodology, we adopted different references for the qualitative research: sociology, history, economy, and education. As for the investigative procedures about the teacher s practices, we related the school s daily practices to the context of the community. We also adopted several investigative procedures, such as questionnaires, interviews, observations and formative intervention. The theoretical basis was organized based on references to curriculum organization, environmental culture, teacher education and also considering the pillars of a capitalistic system that is based on consumerism and that generates social exclusion. At the initial considerations, we contextualized the contemporary environmental issues in an attempt to interpret the conditions of the EE transversality into the school s daily practices, which are still oriented to the traditional Cartesian Education. Based on the collected data, we found the reasons for the teachers dilemma and reluctances to the insertion of the environmental issues into the organization of the work plan and into the management of a school. Nevertheless, the results also signed promising possibilities to the EE tranversality, in case the curriculum of the school could be more sensible towards the cultural and social-economical issues of a community. We especially questioned The National Curriculum Parameter s (PCN), which is considered highly insufficient to inform the teachers about the environmental issues, facing the actual local conditions of social and pedagogic work. The final considerations showed the role and the importance of this research as one strategy to organize the curriculum education into the perspective of the transversality of environmental issues inside the education of both teacher and student

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The theory contemporary in the field of early children education, as well the legal discourse and official texts valid in our country point to the need for systematization of proposals pedagogic / curriculum in institutions, built and carried out by subjects that act as factor of assurance care quality. Quest us about what knowledge are required to teachers in developing a proposed curriculum for children education. Defined as an object of study, the knowledge teachers necessary for the development of a proposed curriculum for children education. As goals, assume: investigate teachers knowledge necessary for the development of a proposed curriculum in a Public Institution for children education and contribute to the (new) meaning on the part of teachers, knowledge needed to build a proposed curriculum for children education. Assuming the principles of the paradigm of qualitative research, we have developed a research institution of a children education Network Public Hall of Ceará-Mirim-RN, which serves children of four and five years old (preschool) with the participation of 17 teachers and two supervisory (teachers) that institution - subject of our research. Therefore, we have adopted the principles of action research, according to which the knowledge gained through research should build so shared / dialogue in the relationship between researcher and participants, what is the implementation of an effective action formative. As the search procedures developed observations no-teaching participants in the meetings and activities of the classroom; semi-structured interviews (individual and collective) with teachers and supervisors; analysis of school documents and participant observation in the seminars of studies reflective. The latter is implemented as key moments of speech and thought, and finally to (new) meaning of knowledge, the subject of the research-action. For these knowledge, the systematization of the register built was developed based on the principles of analysis of Content that guided us to the definition of two categories 1) knowledge teachers concerning conceptions of curriculum / proposed curriculum and 2) knowledge teachers concerning specifics of children education. From these were built subs representing thematings more specific and significant, among the many that emerged in the analysis: 1.1) Definitions of curriculum and curriculum proposal; 1.2) The subjects makers / implementing a curriculum / proposed curriculum; 1.3) elements constituting a curriculum / proposed curriculum for children education and 2.1) Functions of children education and conception of child; 2.2) The space of the play in the organization of routine. Under the intervention could significant advances with regard to (new) meaning of such knowledge from the subjects, with major disruptions to their original designs. These are presented and reflected in this work. In front of this movement, transformation, made the need for a permanent work in the context of the institution of in-service training, or mediated by pedagogical coordinator or other to assume this role with teachers, in order to provide the development and effectiveness of proposed curriculum consistent and contextualized in practice effective with the children concrete envisage the service to their specificities and a quality education

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The present study is based on an analysis of professional work relationships in the nursing team from the task/skills of its members as a contribution to understanding the work process in nursing. It is aimed to identify the skills of the nursing team members through the vision of nurses, technicians and nursing assistants, thus it attempts to find strategies to improve the health assistance to patients. It is a descriptive and analytical study with a qualitative approach grounded in theoretical and methodological framework of Symbolic Interactionism. The research was carried out in the participant work place, a Public Hospital of Reference for the SUS, located in the eastern health district of Natal/RN. Nineteen nursing professionals participated in the study, which seven was nurse and twelve nursing technician. As procedure to collect data we used an unstructured interview accompanied by a standard topic guide which was recorded and later transcribed. The content analysis was chosen as the main methodology to analyze the discussion, which gave rise to thematic categories that were considered relevant based on the theoretical framework of this study, and the interactionist theory. This study was in accordance with the ethical principles of the Resolution nº. 196/96, it has obtained an appropriate consent of the UFRN Research Ethics Committee. The results indicate that the professionals seen the nursing as a profession strongly attached to the health care process and as a profession that acquired a scientific status very recently. Regarding to the nursing functions in the work process in nursing, the professionals they identified the manage/administer category as the main activities developed by these professionals, thus the education and complex care in nursing categories. Concerning to the technicians and nursing assistants functions, it was figured out in the professional s opinion that there is not distinction among the attribution of these categories. The interviewed were unanimous in report that these professionals are more involved in direct patient health care through performance of basic duties in nursing care. Finally, with regard to the work relationship among nursing team members, the majority of those interviewed see this relationship as disharmony and quarrelsome and in general, there is not bond between categories that comprise the process of work in nursing. On the basis of our results we consider the importance of knowing the meaning of nursing given by these professionals; also their skills could be useful as basis to identify problems, which source could be detected in the power relationship, deviations of functions, gap between design (knowledge) and performance (doing) work, besides the loss of the global activities view in the process of nursing work

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This Masters degree dissertation presents a research that aims at analyzing the activities regarding within a hotel managers work in Natal/RN - Brazil, This Masters degree dissertation presents the research that aims at analyzing the activities regarding the hotel managers work in Natal / RN - Brazil, performing diagnosis of their activities and relating the aspects that impact the quality and productivity of hotel services and managers occupational health. This research is characterized as a case study with a qualitative approach, taking the method of Ergonomic Work Analysis which is the analysis of the managers work activity as a reference to the focus; and combining the use of observational and interactional methods. Ergonomics and macroergonomics are used in this study not only to understand the physical, cognitive and organizational constraints of the manager s duties, but also to characterize the work organizational architecture and design of that hotel. High workload, accumulation of tasks and diversion of functions performed by managers were noticed, increasing thereby the physical and psychological suffering for them. It was found that the activity of managers is characterized by the ambivalence of power, limited autonomy, cooperation, interdependence between managers and the fear of incompetence. It was also noticed that managers devote more time to the day job (37%), another time to sleep (30%), while only 33% of the rest of the day are meant for activities like taking care of health, family, social life and study. Although there are few studies addressing the health and safety of hotel managers, this research revealed that 84% of the surveyed hotel managers complain of musculoskeletal pain which 50% are obese and are 100% sedentary. It was also observed that managers adopt unsuitable postures for carrying out the work activities that contribute to becoming injured or work-related musculoskeletal disorders in the near future. Ergonomic measures were recommended as an investment in the skills and the training of managers, encouraging cooperative work, appropriateness of workload, limiting overtime, preserving the enjoyment of breaks during work and weekly holidays, changing the layout of the work sector , usage of communication technology to prevent displacement, compensatory physical activities, furniture adaptation, among others

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This work has as main objective the application of Artificial Neural Networks, ANN, in the resolution of problems of RF /microwaves devices, as for example the prediction of the frequency response of some structures in an interest region. Artificial Neural Networks, are presently a alternative to the current methods of analysis of microwaves structures. Therefore they are capable to learn, and the more important to generalize the acquired knowledge, from any type of available data, keeping the precision of the original technique and adding the low computational cost of the neural models. For this reason, artificial neural networks are being increasily used for modeling microwaves devices. Multilayer Perceptron and Radial Base Functions models are used in this work. The advantages/disadvantages of these models and the referring algorithms of training of each one are described. Microwave planar devices, as Frequency Selective Surfaces and microstrip antennas, are in evidence due the increasing necessities of filtering and separation of eletromagnetic waves and the miniaturization of RF devices. Therefore, it is of fundamental importance the study of the structural parameters of these devices in a fast and accurate way. The presented results, show to the capacities of the neural techniques for modeling both Frequency Selective Surfaces and antennas

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The present work has as objective the knowledge of the process of drying of the cephalothorax of shrimp to give support the industry to make possible the use of this byproduct. In this sense, the process conditions in this tray dryer and spouted bed were analyzed. With these results, it was projected and constructs a dryer with specific characteristics for the drying of the cephalothorax. The desorption isotherms were obtained by the dynamic method in the temperatures of 20, 35 and 50º C and in the interval of 10-90% of relative humidity. It was observed that the product in form of powder can be conserved with larger stability for lower relative humidity to 40%. The curves of drying of the dryer of fixed bed were adjusted for the models: single exponential, biparametric exponential and Page. The model biparametric exponential more adequately described all the drying conditions studied. The tests carry out in spouted bed showed high drying rate for the material in the paste form in beds active dynamicly-fluid, provely the necessity of a feeding in shorter intervals of time to increase the thermal efficiency of the process. The projected dryer, be considered the obtained results, it was a rotary dryer with inert bed, feed co-current, discharge in cyclone to take place the separation gas-solid, and feed carry out in intervals of 2 minutes. The optimization of the equipment projected it was accomplished used the complete factorial experimental design 24, this had as independent variables temperature velocity of the air, feed flow rate and encapsulated concentration (albumin), as variables answers the thermal efficiency, the moisture content of obtained powder, total time of test and the efficiency of production of powder in several points of processing. The results showed that the rotary dryer with inert bed can present, also, good results if applied industrially

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We have used ab initio calculations to investigate the electronic structure of SiGe based nanocrystals (NC s). This work is divided in three parts. In the first one, we focus the excitonic properties of Si(core)/Ge(shell) and Ge(core)/Si(shell) nanocrystals. We also estimate the changes induced by the effect of strain the electronic structure. We show that Ge/Si (Si/Ge) NC s exhibits type II confinement in the conduction (valence) band. The estimated potential barriers for electrons and holes are 0.16 eV (0.34 eV) and 0.64 eV (0.62 eV) for Si/Ge (Ge/Si) NC s. In contradiction to the expected long recombination lifetimes in type II systems, we found that the recombination lifetime of Ge/Si NC s (τR = 13.39μs) is more than one order of magnitude faster than in Si/Ge NC s (τR = 191.84μs). In the second part, we investigate alloyed Si1−xGex NC s in which Ge atoms are randomly positioned. We show that the optical gaps and electron-hole binding energies decrease linearly with x, while the exciton exchange energy increases with x due to the increase of the spatial extent of the electron and hole wave functions. This also increases the electron-hole wave functions overlap, leading to recombination lifetimes that are very sensitive to the Ge content. Finally, we investigate the radiative transitions in Pand B-doped Si nanocrystals. Our NC sizes range between 1.4 and 1.8 nm of diameters. Using a three-levels model, we show that the radiative lifetimes and oscillator strengths of the transitions between the conduction and the impurity bands, as well as the transitions between the impurity and the valence bands are strongly affected by the impurity position. On the other hand, the direct conduction-to-valence band decay is practically unchanged due to the presence of the impurity

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Matrix metalloproteinase-7 (MMP-7) and -9 (MMP-9) modulate important functions strictly related to the development, invasion and metastasis of several human cancers among them the squamous cell carcinoma of the tongue (SCCT). However, individual genetic factors such as the functional single nucleotide polymorphisms (SNPs) influence the pattern of protein expression of these MMPs and thus may be related to the variability observed in the clinical behavior of patients with SCCT. In this context, the present cross-sectional study aimed to evaluate the association between the frequency of the functional SNPs MMP-7 -181 A/G and MMP-9 -1562 C/T and the clinical (age, gender and metastasis) and pathological (malignancy histological grading and immunohistochemistry expression) features of SCCT cases. Genotyping of these SNPs were performed by PCR-RFLP on DNA samples from 71 cases of SCCT and 60 individuals without cancer who constitute the control group. Among the results of this research, it was observed that the frequency of the polymorphic alleles MMP-7 -181 G and MMP-9 -1562 T in SCCT patients was 28% and 12%, respectively, and the frequency of the heterozygotes A/G (PR = 2.00; p < 0.001) and C/T (PR = 1.54; p = 0.014) were significantly higher in the patient group than in the controls. The prevalence of patients carrying the combination of SNPs studied was significantly associated with SCCT cases (PR = 2.00; p = 0.011) and metastasis (PR = 2.00; p < 0.001). Furthermore, with the frequency of SNPs analyzed, the age, gender, histological grading and immunoreactivity of MMP-7 and MMP-9 formed clinical and pathological parameters relevant to the identification of population subgroups more related to the development of SCCT and metastasis. Based on these results, it is suggested that the protein expression levels of MMP-7 and -9 substantially influence the balance between their pro- and anticancer biological functions and hence the clinicopathological profile of the squamous cell carcinoma of the tongue

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The hypothalamus is a diencephalic portion located around the third ventricle below the hypothalamic sulcus, limited by the optic chiasm, and by the mammillary bodies, acting as a center that integrates behavioral and homeostatic functions. Serotonin is a neurotransmitter produced in limited sites in the midbrain and brain stem, but is distributed throughout the central nervous system and has many functions, acting through specific receptors that are also distributed throughout the nervous system. Using immunohistochemical techniques, the aim of this study was to delineate the hypothalamic nuclei of the marmoset (Callithrix jacchus) and study the distribution of serotonin transporter and serotonin receptors in the hypothalamus of this species. We used the Nissl method to determine the cytoarchitecture of the hypothalamic nuclei, and immunohistochemistry to reveal the presence of NeuN as a method to determine the contours of the hypothalamic nuclei. As a result, we found serotonin containing fibers and terminals throughout the rostrocaudal extent of the hypothalamus, more concentrated in some nuclei, and even absent in some. Like serotonin, serotonin transporter was observed between pre-optic area and tuberal region of the hypothalamus, in densities and distribution similar to serotonin. The 5-HT1A and 5-HT1B receptors were found with minor differences among itselves regarding the disposition and intensity of staining.

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The aim of this work is to provide a text to support interested in the main systems of amortization of the current market: Constant Amortization System (SAC) and French System, also known as Table Price. We will use spreadsheets to facilitate calculations involving handling exponential and decimal. Based on [12], we show that the parcels of the SAC become smaller than the French system after a certain period. Further then that, we did a comparison to show that the total amount paid by SAC is less than the French System

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This paper focuses public bus service as an essential component to urban dynamics in Natal, RN. Thereby, the approach of public bus service in Natal City, capital of Rio Grande do Norte State, has as analytical category the concept of territory used, in which techniques are seen as space elements allowing man and nature interact together. The result of this interaction, systematically analyzed in different historical phases, makes space to a geographical assessment of the theme. On a second moment, it is investigated how public bus system came to be and how it functions today in Natal City. In this sense, this paper looks for the main elements that contributed to explain the subject under investigation. For example, how public bus service has accompanied Natal s socio-spatial changes, and eventually, the use of territory carried out in the context of public bus system. These questions are highlighted in this paper because they play a fundamental role to an explanation about public bus circulation, urban vehicle policies and how they affect the use of territory nowadays.