Efeitos da cafeína sobre a memória de saguis (Callithrix jacchus)

Caffeine is considered the most consumed psychostimulant in the world, presenting several central and peripheral effects. In the Central Nervous System the major effect occur by its antagonistic activity at the A1 and A2a subtypes of the adenosine receptors. These receptors are responsible for the slow-wave sleep induction, and their binding, caused by the consumption of foods and beverages that contain caffeine, cause behaviors like increase of alertness, mood and locomotion. The effects of caffeine on memory are still discussed because of the diversity of experimental protocols. Also, it does not have the same effects on all stages of the processing of memory - acquisition, consolidation and recall. Thus, using the marmoset (Callitrhix jacchus) as subject, we aim to evaluate the effects of caffeine on the memory of this primate through the conditioned place preference paradigm, where the animal selects a context by presence of food. This cognitive task consists of five phases. The first phase was two sessions of pre-exposure, in which they were evaluated for preference for any compartment of the apparatus. Then, we proceeded the training, conditioning the animals to the food-present context for 8 days. Then, there was administration of caffeine or placebo (10mg/kg) for 8 consecutive days, during the pre-sleep phase, where the 20 animals were distributed in two groups: placebo and repeated. The forth phase was one day of retraining, a re-exposure of the apparatus to the marmosets followed by the administration of caffeine (for the repeated group and a new group called abstinence) or placebo (for placebo and abstinence groups). Finally, was the test where we evaluated if the subjects learned where the food was present. Moreover, in this work we evaluate the existence of differences between females and males on the task, and the locomotor activity for the experimental groups. The results showed that in the pre-exposure phase the animals were habituated on the apparatus and did not present differences for any contexts. In training, they were able to learn the conditioning task, independent of gender. For the retraining, the two groups exhibited more interactions in rewarded context than that in non-rewarded context. Nevertheless, in the locomotor activity, the repeated group moved similarly in contact with the apparatus and outside of it. In the other hand, the animals of the placebo group moved more when in contact with the apparatus. In the test phase, the marmosets under influence of caffeine presented an increase in the locomotor activity when compared with the placebo group, corroborating works that show this increase in locomotion. In the learning evaluation, the continuous and abstinence groups had a bad performance in the task in relation to the placebo and acute groups. This suggests that the prolonged administration of caffeine disrupts the memories because it affected sleep, which is largely responsible offline processing of memories

Atividade de morcegos insetívoros (mammalia, chiroptera) no pampa brasileiro: uso de hábitat e sazonalidade

Bats correspond to 20% of the extant mammal species and, with a few exceptions, use echolocation, a spacial orientation system based on emission and analysis of echoes from sound waves, generally ultrasounds. Echolocation was discovered in the 1940 s and since the 1970 s ultrasound detectors have been commercially available, allowing the investigation of several aspects of the natural history and ecology of bats. Passive acoustic monitoring has been frequently used in habitat use studies, predominantly in North America and Europe, by comparing the number of bat passes between different habitat types. This dissertation presents the first evaluation of the spacial and seasonal variation patterns in the activity of insectivorous bats in the Brazilian biome Pampa, in the state of Rio Grande do Sul. Since bat activity can vary according to habitat type, time of year and climatic conditions, the following hypotheses were tested: 1. bat activity varies between different types of habitat; 2. bat activity varies seasonally; 3. bat activity is influenced by temperature, humidity and wind speed. The acoustic samples were taken along fixed transects of 1500 meters, which were monitored monthly from April 2009 to March 2010. Five habitat types were sampled: eucalypts, stream, riparian forest, wetland and grassland. In each sample, the number of bat passes was obtained by using an ultrasound detector Pettersson D230. A total of 1183 bat passes were registered. Greater bat activity levels was observed along large eucalypts (1.93 bat passes/3min) and along a stream (1.61 bat passes/3 min). A riparian forest (0.94 bat passes/3 min) and a wetland area (0.61 bat passes/3 min) exhibited statistically equal levels of activity. Bat passes were fewer in grassland areas (0,16 bat passes/3 min). Bat activity was not correlated with abiotic factors. However, bat activity was significantly low in the colder season, winter, and was similar in autumn, spring and summer. The observed preference for vegetation borders and water courses agrees with reports from other countries and is attributed predominantly to the high prey abundance in these types of environments. Additionally, low activity in the winter is probably a response to the reduced availability of insects, and to lower temperatures. Our results indicate which areas of arboreal vegetation and water courses should be priorities for the conservation of bats and that alterations of these habitat types might negatively influence bat activity in the region

Síntese análise das propriedades magnéticas da ferrita de NiMg e características de absorção de radiação

It was synthesized different Ni1-xMgxFe2O4 (0,2 ≤ x ≤ 0,7) compositions by use of citrate precursor method. Initially, the precursory citrates of iron, nickel and magnesium were mixed and homogenized. The stoichiometric compositions were calcined from 350°C to 1200°C at ambient atmosphere or in argon atmosphere. The calcined powders were characterized by XRD, TGA/DTG, FTIR, magnetic measures and reflectivity using the wave guide method. I was observed pure magnetic phase formation between 350°C and 500°C, with formation of ferrite and hematite after 600°C at ambient atmosphere. The calcined powder at argon atmosphere formed pure ferromagnetic phase at 1100°C and 1200°C. The Rietveld analyses calculated the cations level occupation and the crystallite size. The analyses obtained nanometric crystals (11-66 nm), that at 900°C/3h presents micrometric sizes (0,45 - 0,70 Om). The better magnetization results were 54 Am2/Kg for x= 0,2 composition, calcined at 350°C/3h and 30 min, and 55,6 Am2/Kg for x= 0,2 1200°C, calcined in argon. The hysteresis shows characteristics of soft magnetic material. Two magnetization processes were considered, superparamagnetism at low temperature and the magnetic domains formation at high temperatures. The materials presented absorption less or equal the 50 % in ranges specific frequency. As for the 2,0 and 3,0 thickness (in 11,0 - 11,8 GHz), the reflectivity of the x= 0,3, 0,5 and 0,4 compositions, all calcined at 900°C/3h showed agreement with MS and O. Various factors contribute for the final radiation absortion effect, such as, the particle size, the magnetization and the polymer characteristics in the MARE composition. The samples that presented better magnetization does not obtaining high radiation absorption. It is not clear the interrelaction between the magnetization and the radiation absorption in the strip of frequencies studied (8,2 - 12,4 GHz)

Estudo do desempenho de catalisadores tipo Ni/CexM1-xO2 (M = Zr ou Mn) na reação de oxidação parcial do metano

One of the main applications of methane is in the production of syngas, a mixture of hydrogen and carbon monoxide. Procedures used in this process are steam reforming, CO2 reforming, partial oxidation and autothermal reforming. The present study evaluated and compared the behavior of nickel catalysts supported on mixed oxides of cerium and manganese in the partial oxidation of methane with that of nickel catalysts supported on mixed oxides of cerium and zirconium. Mixed oxides of cerium and zirconium or cerium and manganese were synthesized using two different preparation methods, the polymeric precursor based on Pechini method and combustion reaction using a microwave. This was followed by impregnation with nickel content of 15 %. Samples were calcined at 300, 800 and 900 °C and characterized by specific surface area (SSA), X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature programmed reduction (TPR) and the reaction of partial oxidation of methane. The specific areas of samples decrease with the rise in calcination temperature and after nickel impregnation. Metal-cerium solid solution was formed and the presence of other manganese species outside the solid solution structure was confirmed in the compound with the highest amounts of manganese oxides showed. With regard to scanning electron microscopy, supports based on cerium and zirconium prepared by Pechini method exhibited agglomerated particles without uniform geometry or visible pores on the surface. However, compounds containing manganese presented empty spaces in its structure. Through synthesis by combustion reaction, morphology acquired independently of the proposed composition demonstrated greater porosity in relation to Pechini synthesis. Although catalysts were prepared using different synthesis methods, the insertion of nickel showed very similar reduction profiles (TPR). In relation to nickel catalysts supported on mixed oxide of cerium and zirconium, there is an initial reduction of NiO species that present certain interaction with the support. This is followed by the reduction of Ce4+ in Ce3+ surface, with subsequent bulk reduction. For catalysts containing manganese, a reduction of nickel oxide species occurs, followed by two stages of reduction for species Mn2O3 in Mn3O4 and Mn3O4 in MnO, with subsequent reduction of bulk. With respect to partial oxidation reactions, the nickel catalyst supported on mixed oxide of cerium and zirconium, prepared using the Pechini method, exhibited CH4 conversion of approximately 80 %, with conversion of 81 % when prepared by combustion. This behavior continued for 10 hours of reaction. Manganese content was also found to directly influence catalytic activity of materials; the greater the manganese oxide content, the faster deactivation and destabilization occurred in the catalyst. In both synthesis methods, the nickel catalyst supported on mixed oxide of cerium and zirconium maintained an H2/CO ratio very close to 2 during the 10 hours of partial oxidation reaction. Samples containing manganese displayed smaller H2/CO ratios and lower performance in partial oxidation.

Reforma a vapor catalítica do metano: Otimização da produção e seletividade em hidrogênio por absorção in situ do CO2 produzido

Topics of research related to energy and environment have significantly grown in recent years, with the need of its own energy as hydrogen. More particularly, numerous researches have been focused on hydrogen as energy vector. The main portion of hydrogen is presently obtained by reforming of methane or light hydrocarbons (steam, oxy, dry or auto reforming). During the methane steam reforming process the formation of CO2 undesirable (the main contributor to the greenhouse effect) is observed. Thus, an oxide material (sorbent) can be used to capture the CO2 generated during the process and simultaneously shifting the equilibrium of water gas shift towards thermodynamically more favorable production of pure hydrogen. The aim of this study is to develop a material with dual function (catalyst/sorbent) in the reaction of steam reforming of methane. CaO is well known as CO2 sorbent due to its high efficiency in reactions of carbonation and easy regeneration through calcination. However the kinetic of carbonation decreases quickly with time and carbonation/calcination cycles. A calcium aluminate (Ca12Al14O33) should be used to avoid sintering and increase the stability of CaO sorbents for several cycles. Nickel, the industrial catalyst choice for steam reforming has been added to the support from different manners. These bi-functional materials (sorbent/catalyst) in different molar ratios CaO.Ca12Al14O33 (48:52, 65:35, 75:25, 90:10) were prepared by different synthesis methodologies, among them, especially the method of microwave assisted self-combustion. Synthesis, structure and catalytic performances of Ni- CaO.Ca12Al14O33 synthesized by the novel method (microwave assisted selfcombustion) proposed in this work has not being reported yet in literature. The results indicate that CO2 capture time depends both on the CaO excess and on operating conditions (eg., temperature and H2O/CH4 ratio). To be efficient for CO2 sorption, temperature of steam reforming needs to be lower than 700 °C. An optimized percentage corresponding to 75% of CaO and a ratio H2O/CH4 = 1 provides the most promising results since a smaller amount of water avoids competition between water and CO2 to form carbonate and hydroxide. If this competition is most effective (H2O/CH4 = 3) and would have a smaller amount of CaO available for absorption possibly due to the formation of Ca(OH)2. Therefore, the capture time was higher (16h) for the ratio H2O/CH4 = 1 than H2O/CH4 = 3 (7h) using as catalyst one prepared by impregnating the support obtained by microwave assisted self-combustion. Therefore, it was demonstrated that, with these catalysts, the CO2 sorption on CaO modifies the balance of the water gas-shift reaction. Consequently, steam reforming of CH4 is optimized, producing pure H2, complete conversion of methane and negligible concentration of CO2 and CO during the time of capture even at low temperature (650 °C). This validates the concept of the sorption of CO2 together with methane steam reforming

Síntese e caracterização de ferritas de níquel dopadas com cobalto e efeito da substituição nas suas propriedades magnéticas

The ferrite composition Ni1 - xCoxFe2O4 (0 ≤ x ≤ 0.75) were obtained by the method of microwave assisted synthesis and had their structural and magnetic properties evaluated due to the effect of the substitution of Ni by Co. The compounds were prepared: according to the concept of chemical propellants and heated in the microwave oven with power 7000kw. The synthesized material was characterized by absorption spectroscopy in the infrared (FTIR), Xray diffraction (XRD) using the Rietveld refinement, specific surface area (BET) , scanning electron microscopy (SEM) with aid of energy dispersive analysis (EDS) and magnetic measurements (MAV). The results obtained from these techniques confirmed the feasibility of the method of synthesis employed to obtain the desired spinel structure, the ferrite, nickel ferrite as for nickel doped with cobalt. The results from XRD refinement ally showed the formation of secondary phases concerning stages α - Fe2O3, FeO, (FeCo)O e Ni0. On the other hand, there is an increase in crystallite size with the increase of cobalt in systems, resulting in an increased crystallinity. The results showed that the BET systems showed a reduction in specific surface area with the increase of cobalt and from the SEM, the formation of irregular porous blocks and that the concentration of cobalt decreased the agglomerative state of the system. The magnetic ferrites studied showed different characteristics according to the amount of dopant used, ranging from a very soft magnetic material (easy magnetization and demagnetization ) - for the system without cobalt - a magnetic material with a little stiffer behavior - for systems containing cobalt. The values of the coercive field increased with the increasing growth of cobalt, and the values of saturation magnetization and remanence increased up to x = 0,25 and then reduced. The different magnetic characteristics presented by the systems according to the amount of dopant used, allows the use of these materials as intermediates magnetic

Síntese, caracterização de ferritas espinélio com propriedades magnéticas e absorvedoras de microondas

Were synthesized spinel-type ferrites with general formula Ni0,8Mg0.2-xMxFe2O4, where M represents the doping Mn, Co or Mn + Co simultaneously, x ranges for the values 0.02, 0.05 and 0.1. The value of x was divided by 2 in cases where M equals Mn and Co conjugates. We used the citrate precursor method and heat treatment to obtain the phases at 1100°C. The materials were characterized by XRD, TGA/ DTGA, SEM, MAV and reflectivity measurements by the method of waveguide. Powders to 350°C/3.5 h were crystalline and nanosized. According to the results this temperature all powders have a percentage of ferrite phase over 90%. The composition had the addition of Mn and Co simultaneously showed a higher percentage of secondary phase NiO, 5.8%. The TGA/DTGA curves indicate that this sample reached phase (s) crystalline (s) at lowest temperatures. The X-ray diffractograms of the samples calcined at 350°C and 1100°C were treated with the Rietveld refinament technique. The powders calcined at 1100 °C/3h in air show to be 100% except spinel phase composition with 0.02 doping. The micrographs show clusters of particles with sizes smaller than 1 μm in calcination temperature of 1100°C which agreed with the result of Rietveld refinement. In the compositions doped with Mn were higher values of magnetization (45.90 and 53.20 Am2/kg), which did not cause high microwave absorption. The theoretical calculation of magnetization (MT) was consistent with the results, considering that there was agreement between the increase of magnetization experimental and theoretical. It was observed that there was the interrelation of the final effect of absorption with the thickness of MARE, the composition of ferrimagnetic materials and in particular the specific values of frequency. The analysis shows that the reflectivity increases in the concentration of cobalt increased the frequency range and also for absorption 10.17 GHz and 84%, respectively. The best result of chemical homogeneity and the value of 2.96 x 10-2 tesla coercive field were crucial for high performance ferrite absorber with 0.1 cobalt. The Cobalt has high magnetocrystalline anisotropy, it is associated with an increased coercive field, Hc. Therefore, this property improves the results of reflectivity of spinel ferrites

Síntese e caracterização de redes metalorgânicas baseadas em zinco e ácidos benzenodicarboxílicos

Metal Organic Frameworks (MOFs) are supramolecular structures consisted of ions or metal clusters coordinated to organic ligands which are repeated in two or three dimensions. These structures have atracted much attention due to their properties such as low density, high specific surface area and large volume of pores. In this work, MOFs consisted of zinc clusters connected by ditopic ligands, terephthalic acid (1,4- H2BDC) or isophthalic acid (1,3-H2BDC) were synthesized. To obtain the proposed materials, different routes and synthetic parameters were tested, such as the molar ratio of the precursors, the addition of template molecules, the type of solvente, the addition of organic base or the type of a counter-ion of Zn salt. It was found that the variation of these parameters led to the formation of different metalorganic structures. The solids obtained were characterized by XRD, SEM and IR. For the samples identified as MOF- 5, it was verified that the structure was composed of both interpenetrated and non interpenetrated structures. These samples showed a low stability, becoming totally transformed into another structure within less than 72 hours. The addition of the nickel and/or cobalt was found to be a promissing method for increasing the stability of MOF- 5, which in this case, still remained unconverted to another structure even after 15 days of exposure to air. The samples prepared from 1,3-H2BDC were probably new, still unknown Metal Organic Frameworks

Síntese de catalisadores nanoporosos na ausência total e parcial de direcionadores orgânicos para pirólise catalítica de óleos pesados e intermediários

The processing of heavy oil produced in Brazil is an emergency action and a strategic plan to obtain self-sufficiency and economic surpluses. Seen in these terms, it is indispensable to invest in research to obtain new catalysts for obtaining light fraction of hydrocarbons from heavy fractions of petroleum. This dissertation for the degree of Doctor of Philosophy reports the materials preparation that combine the high catalytic activity of zeolites with the greater accessibility of the mesoporosity, more particularly the HZSM-5/MCM-41 hybrid, done by synthesis processes with less environmental impact than conventional ones. Innovative methodologies were developed for the synthesis of micro-mesoporous hybrid material by dual templating mechanism and from crystalline zeolitic aluminosilicate in the absence of organic template. The synthesis of hybrid with pore bimodal distribution took place from one-single organic directing agent aimed to eliminate the use of organic templates, acids of any kind or organic solvents like templating agent of crystalline zeolitic aluminosilicate together with temperature-programmed microwave-assisted, making the experimental procedures of preparation most practical and easy, with good reproducibility and low cost. The study about crystalline zeolitic aluminosilicate in the absence of organic template, especially MFI type, is based on use of H2O and Na+ cation playing a structural directing role in place of an organic template. Advanced characterization techniques such as X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Highresolution Transmission Electron Microscopy (HRTEM), Adsorption of N2 and CO2, kinetic studies by Thermogravimetric Analysis (TGA) and Pyrolysis coupled to Gas Chromatography/Mass Spectrometry (Pyrolysis-GC/MS) were employed in order to evaluate the synthesized materials. Achieve the proposed objectives, has made available a set of new methodologies for the synthesis of zeolite and hybrid micro-mesoporous material, these suitable for catalytic pyrolysis of heavy oils aimed at producing light fraction

Interfaces cérebro-computador: estudo, design e desenvolvimento do jogo AdmiralMind Battleship

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Morfologia e sedimentologia da plataforma continental brasileira adjacente a São Bento do Norte e Caiçara do Norte-RN/NE-Brasil

This dissertation the results of a research developed in the area of São Bento do Norte and Caiçara do Norte, northern coast of the State of Rio Grande do Norte, during the period of June of 2000 to August of 2001, in the ambit of the projects MAMBMARÉ (CNPq/CTPETRO) and PROBRAL (CAPES/DAAD). The objective principal of this research was the characterization of the sedimentary dynamics of this coast, with base in data of coastal process (winds, currents, waves and tides), with topographical risings (beach profiles and dunes), satellite images and sedimentary analyses. The more specific objectives were accomplished the coastal monitoring of this coast, to verify the maintenance of an erosive tendency or progradacional after the groynes construction for contention of the erosion in the beach of Caiçara do Norte, as well as to verify the influence of the features of bottom of the platform interns adjacent on the pole petroliferous of Guamaré. The executed monitoramento allowed to identify that the movement of the sediments, along the year, in that area, is cyclical, reaching the largest oscillations during the months of winter (deposition) and they will summer (erosion). The sedimentologic studies indicated a general tendency for sands quartzosas, with gravel presence, moderately to good selected, with asymmetry predominantly negative. In agreement with the parameter of Dean (1957), used in the identification of the state morfodinâmico of the beaches, monitored beaches, are basically reflectivas with tendency to middlemen, what frames that space of the coast norte-riograndense, as a space strongly vulnerable to erosive processes. The studies developed in the platform, it interns of this area, allowed to visualize for the first time, in large scale, the distribution of the features of the submarine bottom to the batométrico coat of 25 meters. Being pointed out the presence of a high one topographical submerged, with about 5 meters of height, 1 km of width and more than 24 meters of extension, located in the platform it interns in front of São Bento do Norte; coincident with the trend of the system of flaws of Carnaubais. This feature relay an important paper on the control of the sedimentary processes and oceanographic, as well as in the coastal evolution of this area of the RN state, and they affect the area of the pole petroliferous of Guamaré directly. These results contribute to a better knowledge of the processes in the area, and consequently as subsidies implantation of measures of coastal and environmental protection for the cities of São Bento do Norte and Caiçara do Norte, as well as to understand how the geological-sedimentary processes and oceanographic, in this area, are influencing the characteristics geoambientais of the pole petroliferous of Guamaré

Dinâmica Costeira dos Campos petrolíferos Macau/Serra, litoral setentrional do Estado do Rio Grande do Norte

This thesis describes the general behavior of the northern shore of the State of Rio Grande do Norte relating beach profile morphology with hydrodynamic and sedimentological parameters. The Macau and Serra Oil Field are inserted on this area and are under accelerated coastal erosion. At these oil fields are installed oil wells from PETROBRAS, nowadays located directly in the shoreline, under constant attacks of coastal processes (e.g. waves, tides and currents), which promote an intense morphodynamic variability of this sandy coast. The area was monitored for 24 months in three different stations (P01, P02 and P03). The methodology applied involved current techniques of beach profiles, hydrodynamical processes, remote sensing and geophysics. A synthesis of results obtained through the use of different time scales (monthly, lunar cycle, seasonal, annual) from a coastal dynamics study is presented. The average wind direction corresponded to 77ºAz (NE). The steepness of the berm and of the shoreface, as well as coastal current direction, do not present major changes, with an average of 36º for the steepness of the berm, 15º for the shoreface and 15º for the coastal current direction. This data set allows us to infer that the months of larger coastal erosion were November/2000 and April/2001, because of the largest wave parameter during this time. The months of worse coastal erosion in this area are related with the increasing wavy energy. This in turn, seems to be related to seasonal climatic variations, with the wave energy and tide currents speed increasing during months of minor precipitations (June to January). The months of worse coastal erosion were September and November, when the largest wave parameters and speed currents are measured in the area. Since these months are included on the period of minor precipitations, we related the coastal erosion to seasonal climatic variations. The results obtained during these 24 months of monitoring confirms a situation of accentuated erosion, mainly in Profile 03 (Barra do Corta-Cachorro), where the wave height, period, and coastal current speed are always larger than the values found in Profile 02 (Macau5). Probably these values are more expressive in Profile 03, because it does not present any natural structure of protection against the wave impacts, as the barrier island located at Ponta do Tubarão, or the sand banks in front of Macau5. The transport of the sediments occurs from East to West, and the sand accumulation is more pronounced on Profile 03 intertidal zone, where there are embrionary dunes in dryer months. The tidal currents speed, on the other hand, is more accentuated in the Macau5 area (Profile 02). At Ponta do Tubarão, the tidal currents presented a preferential direction for NE, at times of flood, currents and for NW, at times of ebb current; at Barra do Corta-Cachorro the direction of the currents were predominantly for NW, independent of the tide phase, coinciding with the preferential direction of the longshore current. This currents inversion at Ponta do Tubarão is attributed to the presence of the Ponta do Tubarão island barrier and by the communication channel of the lagoon with the sea. The tide currents are better observed in protected areas, as in the Ponta do Tubarão, when they present inversion in their direction accordingly to the flood and ebb tide. In open areas, as in Barra do Corta-Cachorro, the tide currents are overprinted by the longshore currents. Sediment analysis does not show important modifications in grain size related to seasonality (dry- and rainy seasons). On the foreshore and backshore zones, the sediments vary from fine to medium sand, while in the shoreface they very from fine to very sands. The grains are mostly spheres, varying from sub rounded to sub angled. Quartz is the main component alongside Feldspat and heavy minerals as accessory components. Biogenic content is also present and mainly represented by mollusks fragments. The calculated sediment transport show values around 100 m3/day. The morphodynamic studies indicated that this is a reflexive area from October to April, and intermediate from May to September. The Relative Tide Range-RTR for this area is 4 < RTR < 15, and so classified in the mixed wave-tide group. Having this exposed we can affirm that the more active natural factors in this area are the currents, followed by the tides and the winds. The anthropic factors are exclusively local and punctual (Macau and Serra Oil Field). Taking in account the economic importance of the area, as well as the intensity of coastal processes acting on this shore, it is important a continuity of the monthly environmental monitoring looking for variations on longer-period cycles. These data have been stored on the geo-referenced database of the projects MARPETRO and PETRORISCO (REDE 05), aiming to model the coastal and sea environment, susceptible to oil spills and their derivatives

Caracterização do perfil do ciclo sono-vigília em ratos sob dessincronização forçada

The circadian behavior associated with the 24 hours light-dark (LD) cycle (T24) is due to a circadian clock , which in mammals is located in the hypothalamic suprachiasmatic nucleus (SCN). Under experimental conditions in which rats are espoused to a symmetric LD 22h cycle (T22) the two SCN regions, ventrolateral (vl) and dorsomedial (dm), can be functionally isolated, suggesting that each region regulates distinct physiological and behavioral components. The vl region regulates the locomotor activity and slow wave sleep (SWS) rhythms, while the dm region assures the body temperature and paradoxical sleep (PS) rhythms regulation. This research aimed to deepen the knowledge on the functional properties of circadian rhythmicity, specifically about the internal desynchronization process, and its consequences to locomotor activity and body temperature rhythms as well as to the sleep-wake cycle pattern in rats. We applied infrared motion sensors, implanted body temperature sensors and a telemetry system to record electrocorticogram (ECoG) and electromyogram (EMG) in two rat groups. The control group under 24h period LD cycle (T24: 12hL-12hD) to the baseline record and the experimental group under 22h period LD cycle (T22: 11hL- 11hD), in which is known to occur the uncoupling process of the circadian locomotor activity rhythm where the animals show two distinct locomotor activity rhythms: one synchronized to the external LD cycle, and another expressed in free running course, with period greater than 24h. As a result of 22h cycles, characteristic locomotor activity moment appear, that are coincidence moments (T22C) and non coincidence moments (T22NC) which were the main focus or our study. Our results show an increase in locomotor activity, especially in coincidence moments, and the inversion of locomotor activity, body temperature, and sleep-wake cycle patterns in non coincidence moments. We can also observe the increase in SWS and decrease in PS, both in coincidence and non coincidence moments. Probably the increases in locomotor activity as a way to promote the coupling between circadian oscillators generate an increased homeostatic pressure and thus increase SWS, promoting the decreasing in PS

Localização de faltas em linhas de transmissão usando morfologia matemática

This work an algorithm for fault location is proposed. It contains the following functions: fault detection, fault classification and fault location. Mathematical Morphology is used to process currents obtained in the monitored terminals. Unlike Fourier and Wavelet transforms that are usually applied to fault location, the Mathematical Morphology is a non-linear operation that uses only basic operation (sum, subtraction, maximum and minimum). Thus, Mathematical Morphology is computationally very efficient. For detection and classification functions, the Morphological Wavelet was used. On fault location module the Multiresolution Morphological Gradient was used to detect the traveling waves and their polarities. Hence, recorded the arrival in the two first traveling waves incident at the measured terminal and knowing the velocity of propagation, pinpoint the fault location can be estimated. The algorithm was applied in a 440 kV power transmission system, simulated on ATP. Several fault conditions where studied and the following parameters were evaluated: fault location, fault type, fault resistance, fault inception angle, noise level and sampling rate. The results show that the application of Mathematical Morphology in faults location is very promising

Propriedades estáticas e dinâmicas de multicamadas magnéticas acopladas quasiperiodicamente

In this work we study, for two different growth directions, multilayers of nanometric magnetic metallic lms grown, using Fibonacci sequences, in such a way that the thickness of the non-magnetic spacer may vary from a pair of lms to another. We applied a phenomenological theory that uses the magnetic energy to describe the behavior of the system. After we found numerically the global minimum of the total energy, we used the equilibrium angles to obtain magnetization and magnetoresistance curves. Next, we solved the equation of motion of the multilayers to nd the dispersion relation for the system. The results show that, when spacers are used with thickness so that the biquadratic coupling is strong in comparison to the bilinear one, non usual behaviors for both magnetization and magnetoresistance are observed. For example, a dependence on the parity of the Fibonacci generation utilized for constructing the system, a low magnetoresistance step in low external magnetic fields and regions that show high sensibility to small variations of the applied field. Those behaviors are not present in quasiperiodic magnetic multilayers with constant spacer thickness