Regulador automático de tensão robusto utilizando técnicas de controle adaptativo

The stability of synchronous generators connected to power grid has been the object of study and research for years. The interest in this matter is justified by the fact that much of the electricity produced worldwide is obtained with the use of synchronous generators. In this respect, studies have been proposed using conventional and unconventional control techniques such as fuzzy logic, neural networks, and adaptive controllers to increase the stabilitymargin of the systemduring sudden failures and transient disturbances. Thismaster thesis presents a robust unconventional control strategy for maintaining the stability of power systems and regulation of output voltage of synchronous generators connected to the grid. The proposed control strategy comprises the integration of a sliding surface with a linear controller. This control structure is designed to prevent the power system losing synchronism after a sudden failure and regulation of the terminal voltage of the generator after the fault. The feasibility of the proposed control strategy was experimentally tested in a salient pole synchronous generator of 5 kVA in a laboratory structure

Indícios sincrônicos de gramaticalização: o uso do verbo chegar em orações coordenadas e na perífrase verbal [chegar (e) + v2]: contribuições para o ensino de gramática.

Based on North American Functional Linguistic Theory, our proposal is to describe and analyze the use of verb CHEGAR in verbal periphrasis such as [CHEGAR (E) + V2], where CHEGAR does not demonstrate a significance linked to physical movement. In linguistic literature, such periphrasis has been attributed several functions, related to aspectualization, emphasis of negative segments, and construction of mental spaces, among others. This study considers that the function of verb CHEGAR in the periphrasis in question is to indicate a global aspect, emphasizing a range of semantic-pragmatic nuances such as the sudden, instantaneous, or even abrupt character of the events refered to by the principal verb of the construction (V2), and/or the taking of initiative (sudden) by the agent (in the syntactic role of periphrastic subject), and/or subjective evaluations which go from surprise to frustration. Our objectives are the following: i) to describe and analyze the semanticpragmatic, morphosyntactic and social relationships which characterize the use of CHEGAR in verbal periphrases like [CHEGAR (E) + V2] and in coordinated/juxtaposed speech in which CHEGAR is the principal verb of the first utterance and is an elocution verb and the principal verb of the second; ii) identify, based on this description and analysis, synchrony proof in the grammaticalization of CHEGAR as an auxiliary verb in the periphrasis refered to. There was observed to be a strong similarity between coordinate/juxtaposed and periphrastic constructions. Such similarities strengthen the hypothesis that the use of CHEGAR as a lexical verb in coordinate/juxtaposed structures is the origin of the use of CHEGAR in the periphrastic structure, since the many properties encountered with higher frequency in lexical use are also just as frequently used as auxiliaries. Nevertheless, between the two constructions being studied, sufficient difference can be observed to see that CHEGAR, in the periphrasis [CHEGAR (E) V2], is behaving like an auxiliary verb, and shows typical properties of these types of verbs: i) in 100% of occurrences, it does not have a complement;ii) it has a co-referential subject in 100% of cases; iii) it does not appear with intervening material between it and V2. Besides this, CHEGAR, in periphrases, is predominant in nonneutral evaluation contexts, denoted by V2. Inspired by the results obtained, we propose strategies for the discussion of the [CHEGAR (E) V2] periphrases in both elementary and high schools.

Stretch Injuries of Skeletal Muscles: Experimental Study in Rats' Soleus Muscle

The study aimed to verify the physiological injury behavior by stretching the soleus muscle of rats, using a noninvasive experimental model. Twenty-four rats were used and divided into three groups of eight animals: control group (A), group that performed tetanus followed by electrical stimulation and a sudden dorsiflexion of the left paw performed by a device equipped with a mechanism of muscle soleus rapid stretching (B); and a group that only received the tetanus (C). Three days later, the animals were killed, and the soleus muscle was resected and divided into three segments. Morphological changes indicative of muscle damage appeared in all three segments of group B. In a lesser degree, similar changes were also detected in muscles subjected to only tetanus. This model was effective; reproducing an injury similar to what occurs in human sports injuries.

A evolução do lítio em estrelas do tipo-solar através do diagrama HR

Important advances have been made along the last decade in the study of the lithium behavior in solar-type stars. Among the most important discoveries what attracts attention is that the distribution of lithium abundance in the late F-type giant stars tends to be discontinuous, at the same time of a sudden decline in rotation and a gradual decline according to the temperature for giant red stars of such spectral type. Other studies have also shown that synchronized binary systems with evolved components seem to keep more of their original lithium than the unsynchronized systems. evertheless, the connection between rotation and lithium abundance as well as the role of tidal effects on lithium dilution seem to be more complicated matters, depending on mass, metallicity and age. This work brings an unprecedented study about the behavior of lithium abundance in solartype evolved stars based on an unique sample of 1067 subgiant, giant and supergiant stars, 236 of them presenting spectroscopic binary characteristics, with precise lithium abundance and projected rotational speed. Now the lithium-rotation connection for single and binary evolved stars is analyzed taking into account the role of mass and stellar age

Efeitos de interface em bicamadas magnéticas

We study magnetic interface roughness in F/AF bilayers. Two kinds of roughness were considered. The first one consists of isolated defects that divide the substrate in two regions, each one with an AF sub-lattice. The interface exchange coupling is considered uniform and presents a sudden change in the defects line, favoring Neel wall nucleation. Our results show the interface field dependence of the threshold thickness for the reorientation of the magnetization in the ferromagnetic film. Angular profiles show the relaxation of the magnetization, from Neel wall, at the interface, to reoriented state, at the surface. External magnetic field, perpendicular to the easy axis of the substrate, favors the reoriented state. Depending, of the external magnetic field intensity, parallel to the easy axis of the AF, the magnetization profile at surface can be parallel or perpendicular to the field direction. The second one treats of distributed deffects, periodically. The shape hysteresis curves, exchange bias and coercivity were characterized by interface field intensity and roughness pattern. Our results show that dipolar effects decrease the exchange bias and coercivity

Ritmo de atividade de forrageio de Dinoponera quadríceps em ambiente natural

In order to characterize the seasonal and daily rhythm of Dinoponera quadriceps foraging activity in natural environment, four colonies of D. quadriceps were observed in an area of secondary Atlantic forest in northeastern Brazil. Data collection was performed during 72 hours every three months during an annual cycle. Colonies of D. quadriceps exhibited seasonal variation in foraging activity, peaking in the early dry season, followed by a sudden decline at the end of this season and increasing again at the late rainy season. The seasonal rhythm of foraging was positively related to the duration of the daylight and luminosity, and negatively to the time of sunrise and rainfall. Regarding the daily rhythm, foraging activity was predominantly diurnal independent of season. At the early dry season, the colonies had two activity peaks, one in the morning and another in the afternoon, with a decrease in foraging at midday, while in the rest of the year foraging activity was distributed more evenly throughout the daylight. The daily rhythm of foraging activity had a stronger and positive relation with light intensity. The second most important factor determining the daily rhythm of foraging was temperature that was also positively related for most of the year. Relative humidity showed a weak and negative relation with the daily rhythm of foraging in just one month of observation

Black string corrections in variable tension braneworld scenarios

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Escuta clínica e atitude fenomenológica no atendimento à pessoa surda: reflexões sobre um processo psicoterápico

Psychology uses listening as a work resource. When it comes to psychotherapy, listening establishes communication and makes psychologist-client dialogue easier. This qualitative research aims to discuss the clinic listening in phenomenological attitude in existential-phenomenological psychotherapy with deaf people. This perspective is based on the thinking of German philosopher Martin Heidegger, who considers humane a being-with and being-in-the-world, always unveiling meanings. Regarding the deaf people, Libras is currently the natural language of Brazilian deaf people. In this new language configuration, communication occurs in a visual-spatial modality. Thus, listening and speech gain new dimensions, demanding different ways of understanding in the field of psychotherapy. To the development of this research, we present excerpts from therapeutic sessions narratives with a deaf client, interpreted in the light of Heidegger s hermeneutics. We consider that it is possible for the psychotherapist to listen to deaf people in phenomenological attitude. Such position, which does not naturalize and limit the humane, helps so that the clients do not feel responsible for their existence and can hermeneutically converse in their language. In this context, the psychologist must be qualified to conduct the treatment in Libras. We hope that this research can, somehow, fill the existing gap of the scientific production about such theme in the field of Psychology and, mainly, instigate discussion in the context of Psychology courses on the importance and need to qualify psychologists for the management of clinical practice with deaf people

Análise da produção científica nacional fonoaudiológica acerca da linguagem escrita

TEMA: a produção científica nacional sobre a linguagem escrita no âmbito da Fonoaudiologia. OBJETIVO: analisar parte da produção fonoaudiológica brasileira acerca da linguagem escrita, entre os anos de 1980 a 2004, levando em conta o período da publicação; a distribuição de freqüência por período; os tipos de publicações; as sub-temáticas abordadas e a autoria. MÉTODO: a pesquisa de caráter documental configurou a opção metodológica selecionada para a realização desse estudo. Foram analisados livros, capítulos de livros e artigos publicados em sete periódicos nacionais de Fonoaudiologia (1980 a 2004). RESULTADOS: as produções científicas em torno da linguagem escrita, no período considerado, perfazem um total de 236 publicações. Desse total, 3,39% foram publicadas na década de 1980; 44,1% na década de 1990; e 52,5% durante o período de 2000-2004. Quanto ao tipo das publicações, 18,5% foram publicadas em forma de livro, 39% de capítulo de livro e 42,5% de artigo em periódico. Quanto à autoria das publicações, 42 autores (76,36%), são vinculados a instituições de ensino superior, como docentes ou discentes, com maior concentração no Estado de São Paulo e menor no Rio de Janeiro. As produções analisadas versaram sobre cinco sub-temáticas: distúrbios de linguagem escrita (52%); processo de apropriação da linguagem escrita (23,5%); surdez e linguagem escrita (8,90%); alterações neurológicas e linguagem escrita (8,22%) e escola e linguagem escrita (7,53%). CONCLUSÃO: a pesquisa permitiu recuperar parte da memória acerca da construção de um campo de atuação e de conhecimento da área fonoaudiológica: a linguagem escrita. O ascendente crescimento de publicações em torno dessa temática aponta para o implemento de pesquisas nesse campo da Fonoaudiologia e, portanto, a pertinência de estudos que objetivem analisar os rumos da produção científica relativa ao mesmo.

Influence of the elevation of the left ventricular diastolic pressure on the values of the first temporal derivative of the ventricular pressure (dP/dt)

PURPOSE: To assess the effects of the elevation of the left ventricular end-diastolic pressure (LVEDP) on the value of the 1st temporal derivative of the ventricular pressure (dP/dt). METHODS: Nineteen anesthetized dogs were studied. The dogs were mechanically ventilated and underwent thoracotomy with parasympathetic nervous system block. The LVEDP was controlled with the use of a perfusion circuit connected to the left atrium and adjusted to the height of a reservoir. The elevation of the LVEDP was achieved by a sudden increase in the height of a reservoir filled with blood. Continuous recordings of the electrocardiogram, the aortic and ventricular pressures and the dP/dt were performed. RESULTS: Elevation of the LVEDP did not result in any variation of the heart rate (167±16.0bpm, before the procedure; 167±15.5bpm, after the procedure). All the other variables assessed, including systolic blood pressure (128±18.3mmHg and 150±21.5mmHg), diastolic blood pressure (98±16.9mmHg and 115±19.8mmHg), LVEDP (5.5±2.49 and 9.3±3.60mmHg), and dP/dt (4,855 ± 1,082 mmHg/s and 5,149±1,242mmHg/s) showed significant increases following the expansion of the ventricular cavity. Although the elevation of the dP/dt was statistically significant, 6 dogs curiously showed a decrease in the values of dP/dt. CONCLUSION: Sudden elevation of the LVEDP resulted in increased values of dP/dt; however, in some dogs, this response was not uniform.

Processamento e interpretação de dados 2D e 3D de GPR :aplicações no imageamento de feições kársticas e estruturas de dissolução no campo de petróleo de Fazenda Belém-CE

In Fazenda Belém oil field (Potiguar Basin, Ceará State, Brazil) occur frequently sinkholes and sudden terrain collapses associated to an unconsolidated sedimentary cap covering the Jandaíra karst. This research was carried out in order to understand the mechanisms of generation of these collapses. The main tool used was Ground Penetrating Radar (GPR). This work is developed twofold: one aspect concerns methodology improvements in GPR data processing whilst another aspect concerns the geological study of the Jandaíra karst. This second aspect was strongly supported both by the analysis of outcropping karst structures (in another regions of Potiguar Basin) and by the interpretation of radargrams from the subsurface karst in Fazenda Belém. It was designed and tested an adequate flux to process GPR data which was adapted from an usual flux to process seismic data. The changes were introduced to take into account important differences between GPR and Reflection Seismic methods, in particular: poor coupling between source and ground, mixed phase of the wavelet, low signal-to-noise ratio, monochannel acquisition, and high influence of wave propagation effects, notably dispersion. High frequency components of the GPR pulse suffer more pronounced effects of attenuation than low frequency components resulting in resolution losses in radargrams. In Fazenda Belém, there is a stronger need of an suitable flux to process GPR data because both the presence of a very high level of aerial events and the complexity of the imaged subsurface karst structures. The key point of the processing flux was an improvement in the correction of the attenuation effects on the GPR pulse based on their influence on the amplitude and phase spectra of GPR signals. In low and moderate losses dielectric media the propagated signal suffers significant changes only in its amplitude spectrum; that is, the phase spectrum of the propagated signal remains practically unaltered for the usual travel time ranges. Based on this fact, it is shown using real data that the judicious application of the well known tools of time gain and spectral balancing can efficiently correct the attenuation effects. The proposed approach can be applied in heterogeneous media and it does not require the precise knowledge of the attenuation parameters of the media. As an additional benefit, the judicious application of spectral balancing promotes a partial deconvolution of the data without changing its phase. In other words, the spectral balancing acts in a similar way to a zero phase deconvolution. In GPR data the resolution increase obtained with spectral balancing is greater than those obtained with spike and predictive deconvolutions. The evolution of the Jandaíra karst in Potiguar Basin is associated to at least three events of subaerial exposition of the carbonatic plataform during the Turonian, Santonian, and Campanian. In Fazenda Belém region, during the mid Miocene, the Jandaíra karst was covered by continental siliciclastic sediments. These sediments partially filled the void space associated to the dissolution structures and fractures. Therefore, the development of the karst in this region was attenuated in comparison to other places in Potiguar Basin where this karst is exposed. In Fazenda Belém, the generation of sinkholes and terrain collapses are controlled mainly by: (i) the presence of an unconsolidated sedimentary cap which is thick enough to cover completely the karst but with sediment volume lower than the available space associated to the dissolution structures in the karst; (ii) the existence of important structural of SW-NE and NW-SE alignments which promote a localized increase in the hydraulic connectivity allowing the channeling of underground water, thus facilitating the carbonatic dissolution; and (iii) the existence of a hydraulic barrier to the groundwater flow, associated to the Açu-4 Unity. The terrain collapse mechanisms in Fazenda Belém occur according to the following temporal evolution. The meteoric water infiltrates through the unconsolidated sedimentary cap and promotes its remobilization to the void space associated with the dissolution structures in Jandaíra Formation. This remobilization is initiated at the base of the sedimentary cap where the flow increases its abrasion due to a change from laminar to turbulent flow regime when the underground water flow reaches the open karst structures. The remobilized sediments progressively fill from bottom to top the void karst space. So, the void space is continuously migrated upwards ultimately reaching the surface and causing the sudden observed terrain collapses. This phenomenon is particularly active during the raining season, when the water table that normally is located in the karst may be temporarily located in the unconsolidated sedimentary cap

Implicações tectônicas na hidrologia do aqüífero Barreiras e sistema lacustre do Bonfim, Nísia Floresta-RN

This MSc dissertation presents the results of a research carried out in a 500 km2 area in the Nísia Floresta county. The main goal of the research was to evaluate fault influence on hidrology features of aquifers and lakes, mainly in the Barreiras Group and in the Bonfim lake cluster respectively. The Precambrian crystalline basement is made of Caicó Complex rocks. They are capped by cretaceous sedimentary rocks and by cenozoic sedimentary rocks. Only the latter outcrop in the study area, wheareas the former are described in boreholes. Faults cut across all stratigraphic units and their main trends are NW, NE and E-W, which have been generated by E-W compression. Subordinate N-S trending faults also take place and have been generated by N-S oriented compression. Fault controlled hydrologic features are observed throughout the study area. There are sudden changes in saturated thicknesses of the Barreiras Aquifer due to vertical displacement of the Barreiras Group. The most important underground water source of the Bonfim Lake is related to abrupt thickness changes of the aquifer. In addition, the main faults control the underground drainage network and, probably, change in direction of equipotential surfaces seen on the potenciometric map. Regarding the surface hydrologic features, faults also control river and stream channels, as well as lake origin and shapes. The Bonfim Lake, in particular, has its peculiar shape, which follows NW and NE lineaments, and origin related to faulting and probably underground carstics processes

Potencial evocado auditivo para diagnóstico de surdez bilateral em dois cães

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Canine distemper virus infection in a lesser grison (Galictis cuja): first report and virus phylogeny

Doenças infecciosas em animais selvagens têm aumentado devido às alterações em seu habitat e ao maior contato com animais domésticos. A cinomose já foi descrita em diversas espécies de carnívoros selvagens, representando uma ameaça à conservação da vida selvagem. Nesse estudo é descrito o primeiro caso de infecção pelo vírus da cinomose em um furão (Galictis cuja). Um indivíduo de vida livre, sem sinais clínicos aparentes, apresentou morte súbita após um dia em cativeiro. Foi realizado o diagnóstico molecular para detecção do vírus da cinomose canina, sendo o resultado positivo. A filogenia do vírus indicou que cães domésticos foram a provável fonte de infecção.

Performance, incidence of metabolic disturbances and endocrine variables of food-restricted male broiler chickens

1. This experiment was carried out to evaluate the productive and physiological consequences of a slight but long term food restriction of male broiler chickens from 2 commercial strains.2. Cobb-500 and Ross chickens were submitted to a 20% food restriction from 8 to 21 d of age. Strain, food programme and their interactive effects were analysed in terms of consequences upon performance, mortality, incidence of sudden death syndrome (SDS) and ascites syndrome (AS), index of right cardiac hypertrophy and plasma concentrations of hormones related to metabolism and growth (T-3, T-4, T-3:T-4 ratio, IGF-I and GH).3. Although some catch-up growth was observed by refeeding previously restricted birds after 22 d of rearing, food restriction decreased (P less than or equal to 0.05) body weight at market age (42 d) irrespective of the strain, but improved (P less than or equal to 0.05) food conversion.4. The incidence of mortality was not high in non-restricted birds but SDS and AS caused more than 50% of deaths. Hypertrophic cardiac index was observed in chickens of both strains after 4 weeks of age and was higher in ad libitum fed birds.5. During the period of food restriction, plasma T-3 and IGF-I concentrations decreased whereas plasma T-4 and GH concentrations increased compared to those of the age-matched ad libitum fed counterparts. During the subsequent ad libitum feeding period, few differences in circulating hormone concentrations were observed, except for the higher mean CH litres in previously food-restricted chickens at 35 d of age.6. These results indicate that even a non-severe food restriction negatively affects body weight of 42-d-old male broilers but these are benefits with improved food efficiency and diminished mortality from metabolic disturbances. The hormone results suggest that the degree of food restriction applied was not severe because there was a very fast adaptive response with small and transient alterations in T-3, T-4 and GH plasma concentrations during the period of compensatory growth.