14 resultados para mirror

em Universidade Federal do Rio Grande do Norte(UFRN)


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A model of a solar oven with a reflective surface composed of two mirror segments is presented, constituting a two semi-parabolic surfaces made of fiberglass, applied on a ceramic mold, intended to be used in residential and commercial cooking. The reflective surface of the semi-parable is obtained with the use of multiple plain segments of 2 mm wide mirrors. The semi-parabolic structure has visible movements that are comparable to that of the sun. The technical details of the manufacturing and assembling processes will be presented with an analysis of the viability of thermal, economic, and materials of such prototype. This prototype has important social implications and primordial aspects, which combats the ecological damages caused by the wide-scale use of firewood during cooking. It has been demonstrated that the solar oven has the capacity to cook simultaneous two meals distinct for a family of four

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An cylinder-parabolic solar concentrator is presented to produce steam for different applications. This prototype was built in glass fiber with dimensions that follow a study of optimization of parameters inherent in the optical reflection of sunlight by the surface of reflection and absorption of the same by tubing that leads the fluid of work. The surface of the concentrator of 2.24 m² has been covered by layers of mirror with 1.0 m of lenght and 2.0 cm wide. The absorb tubing consists of a copper tube diameter equal to 28 mm. The concentrator is moving to follow the apparent motion of the sun. It will be presented the processes of manufacturing and assembly of the concentrator proposed, which has as main characteristics the facilities construction and assembly, in addition to reduced cost. Will be presented data from tests performed to produce steam setting up some parameters that diagnose the efficiency of the concentrator. It will be demonstrated the viabilities thermal, economic and of materials of the proposed system.The maximum temperature achieved in the vacuum tube absorber was 232.1°C and average temperature for 1 hour interval was 171.5°C, obtained in a test with automation. The maximum temperature achieved in the output of water was 197.7°C for a temperature of 200.0°C in the absorber tube. The best average result of the water exit temperature to interval of 1 hour was 170.2°C for a temperature of 171.2°C, in the absorber tube, obtained in test with automation. Water exit mean temperatures were always above of the water steaming temperature. The concentrator present a useful efficiency of 38% and a production cost of approximately R$ 450,00 ( $ 160.34)

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The manufacturing of above and below-knee prosthesis starts by taking surfac measurements of the patient s residual limb. This demands the making of a cartridg with appropriate fitting and customized to the profile of each patient. The traditiona process in public hospitals in Brazil begins with the completion of a record file (according to law nº388, of July 28, 1999 by the ministry of the health) for obtaining o the prosthesis, where it is identified the amputation level, equipment type, fitting type material, measures etc. Nowadays, that work is covered by the Brazilian Nationa Health Service (SUS) and is accomplished in a manual way being used commo measuring tapes characterizing a quite rudimentary, handmade work and without an accuracy.In this dissertation it is presented the development of a computer integrate tool that it include CAD theory, for visualization of both above and below-knee prosthesis in 3D (i.e. OrtoCAD), as well as, the design and the construction a low cos electro-mechanic 3D scanner (EMS). This apparatus is capable to automatically obtain geometric information of the stump or of the healthy leg while ensuring smalle uncertainty degree for all measurements. The methodology is based on reverse engineering concepts so that the EMS output is fed into the above mentioned academi CAD software in charge of the 3D computer graphics reconstruction of the residualimb s negative plaster cast or even the healthy leg s mirror image. The obtained results demonstrate that the proposed model is valid, because it allows the structura analysis to be performed based on the requested loads, boundary conditions, material chosen and wall thickness. Furthermore it allows the manufacturing of a prosthesis cartridge meeting high accuracy engineering patterns with consequent improvement in the quality of the overall production process

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The use of reflective surfaces functioning as thermal insulator has grown significantly over the years. Reflective thermal insulator are materials that have several characteristics such as low emissivity, low absorptivity and high reflectivity in the infrared spectrum. The use of these materials has grown a lot lately, since it contains several important radioactive properties that minimize the heat loss of thermal systems and cooling systems that are used to block the heat on the roof of buildings. A system made of three surfaces of 316 stainless steel mirror was built to analyze the influence of reflective surfaces as a way to reduce the heat loss and thereby conserve the energy of a thermal system. The system was analyzed both with and without the presence of vacuum, and then compared with a system that contained glass wool between the stainless steel mirror walls, since this isolator is considered resistive and also broadly used around the world in thermal systems. The reflectivity and emissivity of the surfaces used were also measured in this experiment. A type K thermocouple was fixed on the wall of the system to obtain the temperature of the stainless steel mirror surfaces and to analyze the thermal behavior of each configuration used. The results showed an efficiency of 13% when the reflective surfaces were used to minimize the heat loss of the thermal system. However, the system with vacuum had the best outcome, a 60% efficiency. Both of these were compared to the system made of glass wool as a thermal insulator

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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

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This dissertation aims to assess the representativeness of the manual chilled mirror analyzer (model II Chanscope 13-1200-CN-2) used for the determination of condensed hydrocarbons of natural gas compared to the indirect methods, based on thermodynamic models equation of state. Additionally, it has been implemented in this study a model for calculating the dew point of natural gas. The proposed model is a modification of the equation of state of Peng-Robinson admits that the groups contribution as a strategy to calculate the binary interaction parameters kij (T) temperature dependence. Experimental data of the work of Brown et al. (2007) were used to compare the responses of the dew point of natural gas with thermodynamic models contained in the UniSim process simulator and the methodology implemented in this study. Then two natural gas compositions were studied, the first being a standard gas mixture gravimetrically synthesized and, second, a mixture of processed natural gas. These experimental data were also compared with the results presented by UniSim process simulator and the thermodynamic model implemented. However, data from the manual analysis results indicated significant differences in temperature, these differences were attributed to the formation of dew point of water, as we observed the appearance of moisture on the mirror surface cooling equipment

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The mirror has always been related to different symbols, usually connected to self-knowledge and truth. This is due to the fact that this object shows whoever looks oneself in it an image as close to reality as it is possible. On the other hand, the mirror is also associated to mysticism and to the supernatural for it can magically duplicate one who looks into it. This ambiguous characteristic turns the mirror into an element that is fantastic in itself and places it in the central position of our discussion. Therefore, in this study, we analyze the texts In a Glass Darkly, by Agatha Christie, The Oval Portrait, by Edgar Allan Poe, and The Picture of Dorian Gray, by Oscar Wilde, giving special attention to the study of the images and artificial representations of men: the mirror, as an ephemeral representation; and the portrait, as an attempt to eternize an ephemeral image. We also discuss themes such as jealousy, the double, and death in the several forms in which it appears in the texts: suicides, homicides, attempted murders, death in life (mourning, separation, and developmental phases) all of which are, somehow, related to the specular representations. The narrative resource of using a mirror to introduce the supernatural event, along with the theme of death in all the narratives we have studied, and the difficulty to place these texts within the pre-established genres led us to categorize them as being part of a hybrid genre that presents characteristics both of the fantastic and of the detective story which we have named fantastic-detective story

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This paper is divided into three chapters, which are structured as follows: in the first chapter, we examine the figure of death and its characteristics in the context of the work of Guimarães Rosa, within a specific type, determining how this figure comes through " imposition "," no "," memory "and" ritual. " We intend to cover all the possibilities that this aspect denotes. In the second chapter, we found the incidence of the mirror as an analysis of our study, characterizing it as a stylistic condition can become a reading key, necessary for interpretation of the book "First Stories". The characterization of the mirror as an element of analysis has a theoretical foundation which stretches out along other literary works that are based on the same object. By setting the points where these works approach the theories of speculation, we want to justify their use from our perspective

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We indicate the idea of nexus or conexio, thought of as intelligible connection with the intelligent, the foundation on which the reason why you can understand and name, even if inadequately, what the intellect sees incomprehensible and unnameably. Thus, it opens a way for our research: we will take the idea of nexus as fundamental to the interpretation of the divine names and the "metaphysics of the unnameably" and we show how the divine names, mainly in possest, mirrored in the Trinity, relatedness of the principle and therefore also the nexus. For that you need to think some preliminary questions: we will place Nicholas of Cusa in the tradition of medieval Christian Neoplatonism, we resume some discussions on the problem of naming and the philosophy of language in his thinking, we will reflect such thinking is molded from active dialogue with the tradition and how it is your speculation is founded upon the dynamic and dialectical relationship between philosophy and theology to be thought of in our text using the relationship between faith and understandig (intellectus). After introductory clarify these issues we will come to consider introductory understanding of the Trinitarian Beginning and speculation about the nexus taking as its starting point from where the De venatione sapientiae nexus or conexio is designed as a hunting field of wisdom and the First Book of De docta ignorantia where the maximum is now thought of as one and triune. From the Second Book of the same work and the Idiota. De mente we will show in what sense the universe and men, as imago dei, imitate the eternal Trinity. Finally, we will resume the notion of the scientia aenigmatica of De beryllo and some information that will clarify that Nicholas assumes the divine names as enigmas. Finally, we will try to show that the enigmatic or symbolic names also mirror the triune Beginning principle. So, before we return some traces of this aspect in some divine names and texts of the "late period" and then conclude with that which in itself already indicates the nexus and therefore the trinity: possest

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Mirror therapy (MT) is being used as a rehabilitation tool in various diseases, including stroke. Although some studies have shown its effectiveness, little is known about neural mechanisms that underlie the rehabilitation process. Therefore, this study aimed at assessing cortical neuromodulation after a single MT intervention in ischemic stroke survivors, by means of by functional Magnetic Resonance Imaging (fMRI) and Transcranial Magnetic Stimulation (TMS). Fifteen patients participated in a single thirty minutes MT session. fMRI data was analyzed bilaterally in the following Regions of Interest (ROI): Supplementary Motor Area (SMA), Premotor cortex (PMC), Primary Motor cortex (M1), Primary Sensory cortex (S1) and Cerebellum. In each ROI, changes in the percentage of occupation and beta values were computed. Group fMRI data showed a significant decreased in the percentage of occupation in PMC and cerebellum, contralateral to the affected hand (p <0.05). Significant increase in beta values was observed in the following contralateral motor areas: SMA, Cerebellum, PMC and M1 (p<0,005). Moreover, a significant decrease was observed in the following ipsilateral motor areas: PMC and M1 (p <0,001). In S1 a bilateral significant decrease (p<0.0005) was observed.TMS consisted of the analysis of Motor Evoked Potential (MEP) of M1 hotspot. A significant increase in the amplitude of the MEP was observed after therapy in the group (p<0,0001) and individually in 4 patients (p <0.05). Altogether, our results imply that single MT intervention is already capable of promoting changes in neurobiological markers toward patterns observed in healthy subjects. Furthermore, the contralateral hemisphere motor areas changes are opposite to the ones in the ipsilateral side, suggesting an increase system homeostasis.

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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

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The move to include students with special needs (NEE) in the schools presents a paradigm that raises continual discussion about how to implement this proposal. Considering that learning is built from the weaving of socially constructed knowledge and the field of knowledge concerning subjectivity, this research explores the difficulties that occur with the later in the process of inclusion in the schools. Admittedly, the promise implicit in the school does not guarantee that the student learn, but the envisioning of this learning, when the student s educator discredits him, is such that the person is then not taken on as an actual student, being excluded from the transmission of knowledge, even within the school. The project implemented at the Instituto Educacional Casa Escola IECE, for the last three years, shows us that the possibility and sustainability of this envisioning is intimately linked to the subjectivity of the educator, as well as how one relates to the institutional culture. We question then, how this perspective is formed in the educator this perspective capable of denying the offer of a place as student, allowing him to advance while learning. With this in mind, we explore the paradoxical elements present in the paradigm of inclusion, as well as analyzing theoretically, through the body of conceptual psychoanalysis, the process of subjective constitution. We intend to bring to light how this process coincides with the construction of the educator s perspective of exemption from teaching the special needs students. We question, through the formative functions of subjective structuring (The Mirror Stage and the Oedipus Complex), how to form a perspective capable of promoting inclusion of special needs students in educators. Finally, we show how it is possible to bring to light, with the concepts of the I ideal and the ideal I, the subjective difficulties in the practicing instructor

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In this thesis, we investigated the magnonic and photonic structures that exhibit the so-called deterministic disorder. Speci cally, we studied the effects of the quasiperiodicity, associated with an internal structural symmetry, called mirror symmetry, on the spectra of photonics and magnonics multilayer. The quasiperiodicity is introduced when stacked layers following the so-called substitutional sequences. The three sequences used here were the Fibonacci sequence, Thue-Morse and double-period, all with mirror symmetry. Aiming to study the propagation of light waves in multilayer photonic, and spin waves propagation in multilayer magnonic, we use a theoretical model based on transfer matrix treatment. For the propagation of light waves, we present numerical results that show that the quasiperiodicity associated with a mirror symmetry greatly increases the intensity of transmission and the transmission spectra exhibit a pro le self-similar. The return map plotted for this system show that the presence of internal symmetry does not alter the pattern of Fibonacci maps when compared with the case without symmetry. But when comparing the maps of Thue-Morse and double-time sequences with their case without the symmetry mirror, is evident the change in the pro le of the maps. For magnetic multilayers, we work with two di erent systems, multilayer composed of a metamagnetic material and a non-magnetic material, and multilayers composed of two cubic Heisenberg ferromagnets. In the rst case, our calculations are carried out in the magnetostatic regime and calculate the dispersion relation of spin waves for the metamgnetic material considered FeBr2. We show the e ect of mirror symmetry in the spectra of spin waves, and made the analysis of the location of bulk bands and the scaling laws between the full width of the bands allowed and the number of layers of unit cell. Finally, we calculate the transmission spectra of spin waves in quasiperiodic multilayers consisting of Heisenberg ferromagnets. The transmission spectra exhibit self-similar patterns, with regions of scaling well-de ned in frequency and the return maps indicates only dependence of the particular sequence used in the construction of the multilayer

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This work consists of a discussion, analysis and reading of Borges’stories, in that the problem of interest pronounces to the language, to the speech and the deed, sending them so much to the Literature with relationship to the Philosophy, so much to the statute of the ficcional, with relationship to the of the ontologic. In that optics, it intends to show the Borges deed as warp of the death, of the allegorical and of the metaphorical, in the sense of bringing for the ficcional lines different from the Real, elaborating the speech for besides the statement, reaching the interstic, the silence, the interruptions and the suspension of the representation. In that discursive elaboration, a crossing is pointed in the letter, affected for unspeakable sensations, crossing the processes of memory, imaginary and real, in which the time counting makes to emerge the difference and the repetition. In these if constituting territorial negotioting that they lead the characters to imaginary spaces as possibilities of the real, allowing them executes mobility for desterritory it self and reterritory itself, according to the change forces that show in your threshing. For so much, it is placed as mark a bibliographical research orientated by authors as Maurice Blanchot (2008), Kátia Muricy (1998), João Adolfo Hansen (2006), Susan Sontag (2007), Mário Bruno (2004), Juan Manuel García Ramos (2003), Elizabeth Kübler Ross (2008), Walter Benjamin (1984), Gilles Deleuze (1997; 2006; 2009), Gilles Deleuze and Félix Guattari (1995; 1996; 1997). The theoretical corpus and of discussion, it is constituted to leave of those authors, assisting to the implicit qualitative character in the construction of this thesis. What about to the literary corpus, this is composed by the stories The writing of the God, The two kings and the two labyrinths, The lottery of Babylon, The metaphor, The library of Babel, The mirror and the mask, A theologian in death and The dead man.