65 resultados para Deflexão gravitacional da luz


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Qué se piensa aquí, esencialmente, está a mapear el itinerario de la melancolía creativa en el discurso de Dom Casmurro; es decir, aquél de el cual el valle narrativo de una sensación de la angustia a alçar él él las maneras de la representación en el discurso de Dom Casmurro. El árbol básico en el cual éste estimaba incurre en se basa en el acuerdo de eso que la actual melancolía en el texto del machadiano se puede analizar por las estratagemas de la lengua creativa en la intención de demostrar en él una especie del espacio virtual - el conducir de metáforas, de ironies y del exacerbamento de imágenes - por cuál se prepone el narrador construir su salvación . El propósito es analizar el uso de el proyecto del alegórico y el irónico previstos por el autor en la intención de descubrir pues tales procedimientos contribuyen para crear un texto ese desestabiliza el carácter malsano de la melancolía. Puede propagar lengua creativa de tal manera cuánto otras maneras de la representación de eso las marcas del arte utilizan. Más allá de este traz poético, la contribución de este trabajo también constituye: para componer una escena en la cual el teatralidade de la lengua de Dom Casmurro constituye drama y no tragedia. Después de la pista de los conceptos de los benjaminianas de la melancolía, alegoria, metalenguaje la ironía, vimos que éstos disalign de la voluntad que los estatutos se estabilizaron de las figuras del retórico para consistir mientras que las estrategias de los discursivas. Subyacente a este proceso es posible percibir el flash del rescate de la escritura melancholic, visto bajo luz del saturnine de una mirada que si desea alegórico, en la misma incandescencia de la risa del fáustico

Relevância:

20.00% 20.00%

Publicador:

Resumo:

From the many weavers known, the Queen of Ithaca is certainly among the most famous.Over the years,many writers have dedicated themselves to retell the myth of Penelope in their works by their own way. According to Ute Heidmann, the modern writers recurrence to the Greek myths in order to produce their texts is a renewing discursive practice, which gives new writing and relevance to the myth. (2003, p.47). This work deals with a differential and discursive comparative analysis on the myth of Penelope linking it with two short stories from Brazilian authors: Penélope by João do Rio (1919) and Penélope by Dalton Trevisan (1959). In order to do it, we are supported by: the works of Heidmann (2003, 2006, 2008) and Maingueneau (2006). We also concentrate ourselves on the temporal trace presented in both Penelope s myth and in its modern rewriting so that we can identify how each configuration of the classical myth develops into one of the most celebrated acts of this myth: the waiting. In order to so, we seek support on the studies by Paul Ricoeur (2006), Hans Meyerhoff (1976) and Benedito Nunes (1988)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The infographics historically experience the process of evolution of journalism, from the incipient models handmade in the eighteenth century to the inclusion of computers and sophisticated software today. In order to face the advent of TV against of the partiality readers of the printed newspaper, or to represent the Gulf War, where not allowed photography, infographics reaches modern levels of production and publication. The technical devices which enabled the infographics to evolve the environment of the internet, with conditions for the manipulation of the reader, incorporating video, audio and animations, so styling of interactive infographics. These digital models of information visualization recently arrived daily in the northeast and on their respective web sites with features regionalized. This paper therefore proposes to explore and describe the processes of producing the interactive infographics, taking the example of the Diário do Nordeste, Fortaleza, Ceará, whose department was created one year ago. Therefore, based on aspects that guide the theory of journalism, as newsmaking, filters that focus on productive routine (gatekeeping) and the construction stages of the news. This research also draws on the theoretical framework on the subject, in concepts essential characteristics of computer graphics, as well as the methodological procedures and systematic empirical observations in production routines of the newsroom who can testify limitations and / or advances

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of the present dissertation constitutes to analyse the way in how light assumes the meaning of universal bond in the cosmovision of Marsilio Ficino, especially from his works Quid sit lumen, De Sole, De Amore and De Vita. The influence of Marsilio Ficino (1433-1499) in the history of occidental thought is impressive. Besides having translated to Latin the important texts of the neoplatonic tradition, Ficino presided over the Academy of Careggi, congregating important humanists in the top of the Renaissance. His treatises on love, beauty, light, magic and immortality of the soul have influenced strongly the production of other thinkers. The subject of light is of fundamental importance among his works since it is deeply related with all the other aspects of his philosophy. For him, light is spiritual emanation that perpasses everything without staining itself. Originated how the divine goodness, the light blows up in beauty in multiplicity, setting fire on the soul that truily contemplates it and that identifies whith it. The starting point of this loving relation between man and deity is, therefore, the physical world, that occults in itself the metaphysical light.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work s objective is to make a literal interpretation of Kant s Aesthetic transcendental, the first pilaster of sustentation of the epistemology of Kant and to interpret it at Strawson s light. It contains the doctrine of sensitivity responsible for the intuitions, which rests on the concepts of space and time, and, with this, the tematização of two important questions. For Kant s philosophy in its epistemologic source what s the importance of the concepts of and time? How these concepts of space and time inscribe themselves with such statute as an investigatory task of metaphysics? The specification of the concepts of space and time as ingredients of the theories treated and enrolled in this work are segmented of the Aesthetic transcendental of Kant, and interpreted under Strawson s light. The research is divided in two chapter; first, constituted of two parts, the first part presents an introduction to the Aesthetic transcendental of Kant, to show the doctrine of the sensitivity which is part of with its forms space and time, authentic forms of the intuition. The second chapter, is constituted of four parts, that deal with the interpretation of the austere model of Strawson and related with Kant s transcendental Aesthetic. The conclusion of our work, about the declared objection of Strawson in its austere interpretation that refuses the idea of space and time, even keeping its a priori character, cannot be accepted. The apriority, the intuitivity and the ideality are theories non-separable in a coherent boarding of space and time of Kant s model of epistemology

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Recent astronomical observations (involving supernovae type Ia, cosmic background radiation anisotropy and galaxy clusters probes) have provided strong evidence that the observed universe is described by an accelerating, flat model whose space-time properties can be represented by the FriedmannRobertsonWalker (FRW) metric. However, the nature of the substance or mechanism behind the current cosmic acceleration remains unknown and its determination constitutes a challenging problem for modern cosmology. In the general relativistic description, an accelerat ing regime is usually obtained by assuming the existence of an exotic energy component endowed with negative pressure, called dark energy, which is usually represented by a cosmological constant ¤ associated to the vacuum energy density. All observational data available so far are in good agreement with the concordance cosmic ¤CDM model. Nevertheless, such models are plagued with several problems thereby inspiring many authors to propose alternative candidates in the relativistic context. In this thesis, a new kind of accelerating flat model with no dark energy and fully dominated by cold dark matter (CDM) is proposed. The number of CDM particles is not conserved and the present accelerating stage is a consequence of the negative pressure describing the irreversible process of gravitational particle creation. In order to have a transition from a decelerating to an accelerating regime at low redshifts, the matter creation rate proposed here depends on 2 parameters (y and ߯): the first one identifies a constant term of the order of H0 and the second one describes a time variation proportional to he Hubble parameter H(t). In this scenario, H0 does not need to be small in order to solve the age problem and the transition happens even if there is no matter creation during the radiation and part of the matter dominated phase (when the ß term is negligible). Like in flat ACDM scenarios, the dimming of distant type Ia supernovae can be fitted with just one free parameter, and the coincidence problem plaguing the models driven by the cosmological constant. ACDM is absent. The limits endowed with with the existence of the quasar APM 08279+5255, located at z = 3:91 and with an estimated ages between 2 and 3 Gyr are also investigated. In the simplest case (ß = 0), the model is compatible with the existence of the quasar for y > 0:56 whether the age of the quasar is 2.0 Gyr. For 3 Gyr the limit derived is y > 0:72. New limits for the formation redshift of the quasar are also established

Relevância:

20.00% 20.00%

Publicador:

Resumo:

One of the main goals of CoRoT Natal Team is the determination of rotation period for thousand of stars, a fundamental parameter for the study of stellar evolutionary histories. In order to estimate the rotation period of stars and to understand the associated uncertainties resulting, for example, from discontinuities in the curves and (or) low signal-to-noise ratio, we have compared three different methods for light curves treatment. These methods were applied to many light curves with different characteristics. First, a Visual Analysis was undertaken for each light curve, giving a general perspective on the different phenomena reflected in the curves. The results obtained by this method regarding the rotation period of the star, the presence of spots, or the star nature (binary system or other) were then compared with those obtained by two accurate methods: the CLEANest method, based on the DCDFT (Date Compensated Discrete Fourier Transform), and the Wavelet method, based on the Wavelet Transform. Our results show that all three methods have similar levels of accuracy and can complement each other. Nevertheless, the Wavelet method gives more information about the star, from the wavelet map, showing the variations of frequencies over time in the signal. Finally, we discuss the limitations of these methods, the efficiency to give us informations about the star and the development of tools to integrate different methods into a single analysis

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this work we obtain the cosmological solutions and investigate the thermodynamics of matter creation in two diferent contexts. In the first we propose a cosmological model with a time varying speed of light c. We consider two diferent time dependence of c for a at Friedmann-Robertson- Walker (FRW) universe. We write the energy conservation law arising from Einstein equations and study how particles are created as c decreases with cosmic epoch. The variation of c is coupled to a cosmological Λ term and both singular and non-singular solutions are possible. We calculate the "adiabatic" particle creation rate and the total number of particles as a function of time and find the constrains imposed by the second law of thermodynamics upon the models. In the second scenario, we study the nonlinearity of the electrodynamics as a source of matter creation in the cosmological models with at FRW geometry. We write the energy conservation law arising from Einstein field equations with cosmological term Λ, solve the field equations and study how particles are created as the magnetic field B changes with cosmic epoch. We obtain solutions for the adiabatic particle creation rate, the total number of particles and the scale factor as a function of time in three cases: Λ = 0, Λ = constant and Λ α H2 (cosmological term proportional to the Hubble parameter). In all cases, the second law of thermodynamics demands that the universe is not contracting (H ≥ 0). The first two solutions are non-singular and exhibit in ationary periods. The third case studied allows an always in ationary universe for a suficiently large cosmological term

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ce travail est un étude de cas qui analyse la construction litéraire du paysage du « Sertão» du Ceará entre la fin du siècle XIX et le début du siècle XX. Pour cela, quelques oeuvre simbole de la production litéraire du Ceará ont été sélectionnés, comme les textes qui suivent: O sertanejo (1875), de José Martiniano de Alencar; Os retirantes (1879), de José Carlos do Patrocínio; A fome (1890), de Rodolfo Marcos Teófilo; Luzia-Homem (1903), de Domingos Olímpio Braga Cavalcanti; Terra de sol: natureza e costumes do Norte (1912), de Gustavo Dodt Barroso et finalement, Aves de arribação (1914), de Antônio Sales. Ces oeuvres non seulement prend la nature comme personage, elles représentent aussi trois moments de la production litéraire du Ceará : romantique, réaliste et naturaliste. A invenção da Terra da Luz se rapporte à l idée d une littérature qui fait remarquer le paysage diurne du Sertão du Ceará, élaborée par ces hommes des lettres dans ses discours formidables, beaux et des matériaux qui viennent de ses rapports avec le monde naturel. Pour réaliser une tel entreprise, les idées de Edmund Burke et Gaston Bachelard se sont constitués en référence de cet étude. Et cette réflexion sur la description, la rêverie et l imagination marchent côte-à-côte au discours de ces littéreurs qui ont construits un espace simbolique spécifique : le sertão du Ceará. Comme ça, quelques thèmes deviennent canonique à la forme de penser, représenter et imaginer l espace du sertão du Ceará. De cette manière, le paysage est beaucoup plus que la contemplation, une fois qu elle est liée aussi à la rêverie poétique, à la mémoire et l imagination. C est de là l invention du paysage, car ces littéreurs n ont pas l accès au paysage purement naturel parce que ses perceptions et sensibilitées sur le monde du sertão ont été historiquement, c est-à-dire, dans un certain temps et espace

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Assuming that the subject is a draft work in permanent invention, the biographical texts, memories written by Luís da Câmara Cascudo, between 1967 and 1969 were read as part of a discursive strategy created by the potiguar memorialist regarding the construction of a self-image profoundly connected to the space of his house, which decisively collaborated so that the province teacher and researcher after announcing his official retirement in 1968 was revered in the city where he had been born, grown up and lived throughout his whole life and considered as the prophet of his own country (or rather, as the literary patron of Natal). Our work begins with some reading about the manner as the potiguar memorialist selected, ordered and spatialized his childhood memories. In the following chapter, we problematized the meanings assigned by Câmara Cascudo to his house in Tirol - where the young prince Cascudinho (little Cascudo) used to live - transformed into the neighborhood principality. It finishes with memories from the retired old man with the purpose of making us think about the sacredness process master Cascudo s house has gone through. The space where he had lived for almost forty years of his life and produced a great part of his works, was elected as a monument in his memory, as his own incarnation, as guarantee of his eternity and perenniality, as a sanctuary and place of worship and have been kept by the actions that, still nowadays, institutionalize it as his sacred space

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Photodynamic therapy (PDT) has been proposed as an alternative method for the treatment of biofilm-dependent oral diseases like dental caries. This therapy consists of simultaneous action of a visible light (L) and a photosensitizer (FS) in the presence of oxygen, which leads to production of different reactive oxygen species that can interact with the bacterial cell components, and promote cell death. This study aims to evaluate the antimicrobial action of PDT on oral bacteria in suspension, as well as the formation of mono and multi-species biofilms, in vitro, from a standard strain of Streptococcus mutans (ATCC 25175) and saliva samples, respectively. The dye methylene blue (MB) and toluidine blue (TB) were used at a concentration of 100 mg/ L and activated by halogen light (600 to 750 nm) from a modified hand held photopolymerizer (Ultralux ®, Dabi Atlante, Ribeirão Preto , São Paulo, Brazil.). Planktonic cultures were prepared and submitted to different experimental conditions: 1. PDT using TB 2. PDT using MB, 3. L+ FS- , 4. TB + L - ; 5. MB+ L-; 6. L- FS- (negative control) and 7. administration of 0.12% chlorhexidine digluconate (positive control) (Periogard ®, Colgate-Palmolive Company, New York, USA). The immediate and mediated action of PDT on bacterial suspensions, as well as its effect on biofilm formation were observed from the number of colony-forming units per milliliter (CFU/mL) and measures optical density (OD). The data were statistically analyzed using the Kruskal-Wallis and Mann-Whitney test for the significance level of 5%. According to the results, the PDT showed no antibacterial action on suspensions of S. mutans, regardless of the dye used. PDT with MB activated by halogen light was able to reduce 86.6% CFU/mL multi-species planktonic cultures, however, this reduction was not significant (p > 0.05). PDT showed antibacterial effect, mediate on multi-species planktonic cultures with TB (p < 0.001) and MB (p < 0.001), activated by halogen light. PDT was able to prevent the formation of multispecies biofilm, through the activation of TB by halogen light (p = 0.01). We conclude that activation of the dye toluidine blue and methylene blue, by halogen light (PDT) showed antimicrobial activity, compared to multi-species planktonic cultures prepared from saliva samples

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In adolescents, who tend to sleep and wake-up later, the school schedule in the morning is associated with sleep advancement and shortening besides bedtime and wake-up time irregularity between week and weekend days. As a result, there is an increase in daytime sleepiness and a drop in cognitive performance that interfer in students performance in classroom. These consequences reinforce the need to evaluate alternatives that help the adolescent to adapt their sleep needs to the time of start of classes in the morning. Accordingly, the general aim of this study was to evaluate the effects of a sleep program education and sunlight exposure in early morning on sleep-wake cycle (SWC) and daytime sleepiness of adolescents. The students chronotype were evaluated by the Horne-Ostberg questionnaire and the health and usual sleep habits by "the health and the sleep questionnaire. The SWC patterns were assessed by sleep log, the daytime sleepiness by Karolinska Sleepiness Scale (KSS) and the alertness by the Psychomotor Vigilance Test (PVT). These parameters were compared before and after a sleep education program and before and during the sunlight exposure. The sleep program was effective in increasing sleep knowledge of adolescents, in promoting a reduction of bedtime and wake-up time irregularity and increasing the sleep duration in school days. The sunlight exposure effect was evaluated in the return to classes after vacation due to the difference in sleep patterns between school and vacation days. During the intervention week it was observed an advance of sleep schedules, an increase on sleep duration and alertness at the end of the morning. Assessed separately, sleep education and sunlight exposure should contribute to minimize adolescents partial sleep deprivation, but daytime sleepiness effect must be better investigated. These strategies should be used jointly by school members to improve health and performance of their students

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The sleep onset and offset delay at adolescence in relation to childhood. Besides biological causes, some external factors as academic obligations and socialization contributes, increasing the burden of school and socialization. However, morning school schedules reduce sleep duration. Besides light strong effect, studies in humans have indicated that exercise influence circadian synchronization. To evaluate the effect of the morning exercise under sunlight on sleep-wake cycle (SWC) of adolescents, 160 high school students (11th year) were exposed to the following conditions: lesson in usual classroom (Group C), lesson in swimming pool exposed to sunlight (Group E), half of them carrying through physical activity (EE) and the other resting (EL). Each experimental group met two stages: assessment of SWC 1 week before and 1 week during the intervention, which was held in Monday and Wednesday between 7:45 and 8:30 am. In the baseline, there were applied the questionnaires "Health and Sleep" and cronotype evaluation (H & O). In addition, students were evaluated before and during the intervention by "Sleep Diary", "Karolinska Sleepiness Scale" (KSS), Psychomotor Vigilance Test (PVT) and actimetry. During the intervention, there was a delay in wake-up time on the weekend and a trend to greater sleep duration on week for the three groups. At the weekend, only the groups EE and EL increased sleep duration. There was no difference in bedtime, irregularity of sleep schedules and nap variables. The sleepiness showed a circadian pattern characterized by higher alertness levels at 11:30 am and sleepiness levels at bedtime and wake-up time on week. On weekends there were higher levels of alertness in these times. In the days of intervention, there was an increase of sleepiness at 11:30 am for groups EL and EE, which may have been caused by a relaxing effect of contact with the water of the pool. In addition, the group EE showed higher alert levels at 14:30 pm on Monday and at 8:30 am in the Wednesday, possibly caused by exercise arousal effect. The reaction time assessed through the TPV did not vary between the stages. The sleep quality improved in the three groups in the second stage, making impossible the evaluation of intervention effect. However, the sleep quality increased on Monday and Tuesday only on the group EE. From the results, it is suggested that the intervention promoted effects on the sleepiness at some day hours. In other SWC variables there were no effects, possibly due to a large SWC irregularity on weekends. Thus, the evaluation of higher weekly frequency EF is necessary, since only two days were insufficient to promote greater effect on adolescents SWC

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Marmosets, Callithrix jacchus, are strictly diurnal animals. The motor activity rhythmicity is generated by the circadian timing system and is modulated by environmental factors, mainly by photic stimuli that compose the light-dark cycle. Photic stimuli can reset the biological oscilators changing activity motor pattern, by a mechanism called entrainment. Otherwise, light can act directly on expressed rhythm, without act on the biological oscillators, promoting the masking. Thus, photic stimuli can synchronize the circadian activity rhythm (CAR) by two distinct mechanisms, acting isolated or at a combined way. Among the elements that can influence photic synchronization, the duration and time of photic exposure is pointed out. If in the natural environment the marmoset can choose places of different intensity illumination and is synchronized to light-dark cycle (LD), how the photic synchronization mechanism can be evaluated in laboratory by light self-selection? With objective to response this question, four adult male marmosets were studied at two conditions: with and without sleeping box. The animals were submitted to a LD cycle (12:12/ 350:2 lx) and constant light (LL: 350 lx) conditions in individual cages with an opaque sleeping box, that permitted the light self-selection. At the room, the temperature was 25.6 ºC (± 0.3 ºC) and humidity was 78.7 (± 5%). The motor activity was recorded at 5 min bins by infrared movement sensors installed at the top of the cages. The motor activity profile was distinct at the two conditions: without the sleeping box protection against light, the activity frequency was higher at CT 11-12 (ANOVA; F(3.23) = 62.27; p < 0.01). Also, the duration of the active phase (α) was prolonged of about 1 h (t test, p < 0.05) and the animals showed a significant delay on the activity onset and offset (t test, p < 0.05) and at the acrophase (confidence intervals of 5%) of CAR. In LL, the light continuous exposure prolonged the active phase and influenced the endogenous expression of the circadian activity rhythm period. From the result analysis, it is concluded that the light self-selection can modify several parameters of CAR in marmosets, allowing the study of the synchronization mechanism using the burrow model. Thus, without sleeping box there was a phase delay between the CAR and LD (entrainment) and an increase of activity near lights off (positive masking). Furthermore, in LL, the light continuous exposure modifies α and the endogenous expression of CAR. It is suggested that the light self-selection might be take into account at investigations that evaluate the biological rhythmicity in marmosets