Determinação da toxicidade aguda e caracterização de risco ambiental do herbicida Roundup (glifosato) sobre três espécies de peixes

Considering their commercial importance, as these are the species of freshwater fish more commercialized in Brazil, their occurence in different kinds of aquatic environments (lakes, rivers and dams) and for being tolerant to a wide range of variation of various physical parameters and chemical water, the fish species Oreochromis niloticus, Cyprinus carpio and Colossoma macropomum were chosen for this study, furthermore, to test the toxicity we used the herbicide Roundup. The fingerlings of tilapia (Oreochromis niloticus), commun carp (Cyprinus carpio) and tambaqui (Colossoma macropomum) were submitted to the herbicide roundup in the following concentrations: 0.0 (control); 18,06; 19,10; 20,14; 21,18 and 22,22 mg.L-1, 0.0 (control); 13,89; 14,86; 15,83; 16,81 and 17,78 mg.L-1, and 0.0 (control); 18,06; 19,10; 20,14; 21,18 and 22,22 mg.L-1, respectively, three for 96 hours. The LC50 - 96h for O. niloticus, C. carpio and C. macropomum was 21,63, 15,33 and 20,06 mg.L-1 of the herbicide roundup, respectively. The results show that this herbicide is classified as slightly toxic to the three species. The values of dissolved oxygen, pH and temperature recorded in the aquarium control and aquarium experimental of the three fish species have remained without significant variations during the tests, which reduces the possibility of death caused by sudden variations of these parameters during the 96 hours the experiment. The values of LC50 between different species of fish were observed, noting that the species O.niloticus, C. carpio and C. macropomum showed no expressive differences. The values of environmental risk of Roundup were calculated to obtain more stringent parameters in assessing the dangerousness of those on nontargets. The risk of environmental contamination by Roundup for the Nile tilapia, common carp, and tambaqui are low for the lowest application rate (1 L.ha-1) and depths (1.5 and 2.0 m). The dilution of 100%, the highest recommended dose (5 L.ha-1) and depths (1.5 and 2.0 m) the risk is moderate for the three species. The values of the Risk Ratio (QR) were greater than 0,1, indicating that the values of the CAE and LC50 are above acceptable levels and there is a need, this study, a refinement in ecotoxicological tests

Estudo sobre as potencialidades de compósitos à base de gesso e fibras de coco seco para aplicação na construção civil

The use of gypsum, one of the oldest building materials for the construction industry in the country has been experiencing a significant and steady growth, due to its low cost and some of its properties that confer comparative advantage over other binder materials. Its use comprises various applications including the coating of walls and the production of internal seals and linings. Moreover, the fibers are being increasingly incorporated into arrays fragile in an attempt to improve the properties of the composite by reducing the number of cracks, the opening of the same and its propagation velocity. Other properties, depending on the function of the component material or construction, among these thermal and acoustic performances, are of great importance in the context of buildings and could be improved, that is, having better performance with this embodiment. Conduct a comparative study of physico-mechanical, thermal and acoustic composite gypsum incorporating dry coconut fiber, in the form of blanket, constituted the main objective of this work. Improving the thermal and acoustic performances of precast gypsum, used for lining and internal vertical fences of buildings, was the purpose of development of these composites. To evaluate the effect of fiber content on the properties of the composites were used to manufacture the composite layer with different thicknesses. The composites were fabricated in the form of plates with dimensions of 500x500x24mm. To facilitate the comparative study of the properties were also made with material gypsum boards only. We then determined the physico-mechanical, thermal and acoustical plaster and composites. The results indicated that the composites were significant gains in relation to thermal performance and also acoustic, in certain frequency range, increasing the thickness of the blanket. Concerning other physical-mechanical properties, the results showed that although the compressive strength was lower than for the composite did not occur after a fracture catastrophic failure. The same trend was observed with regard to resistance to bending, since the composites have not suffered sudden rupture and still continued after the load supporting point of maximum load

Cinemática de partículas em fluidos de viscosidade variável com o tempo e sua aplicação na construção de poços de petróleo: avaliação durante paradas operacionais

The new oil reservoirs discoveries in onshore and ultra deep water offshore fields and complex trajectories require the optimization of procedures to reduce the stops operation during the well drilling, especially because the platforms and equipment high cost, and risks which are inherent to the operation. Among the most important aspects stands out the drilling fluids project and their behavior against different situations that may occur during the process. By means of sedimentation experiments, a correlation has been validated to determe the sedimentation particles velocity in variable viscosity fluids over time, applying the correction due to effective viscosity that is a shear rate and time function. The viscosity evolution over time was obtained by carrying out rheologic tests using a fixed shear rate, small enough to not interfere in the fluid gelling process. With the sedimentation particles velocity and the fluid viscosity over time equations an iterative procedure was proposed to determine the particles displacement over time. These equations were implemented in a case study to simulate the cuttings sedimentation generated in the oil well drilling during stops operation, especially in the connections and tripping, allowing the drilling fluid project in order to maintain the cuttings in suspension, avoiding risks, such as stuck pipe and in more drastic conditions, the loss of the well

Contribuição da catodoluminescência para o entendimento da diagênese da formação Jandaíra: áreas do campo de petróleo da fazenda Belém e Lajedo do Rosário

The general objective of this study was to contribute to the understanding of the chemical evolution of fluids that percolate through carbonate rocks of the Jandaíra Formation. The oxidation and reduction conditions in which grains, source and cement were formed was investigated using the cathodoluminescence technique (CL). The study area is located in the west part of the Potiguar Basin (Fazenda Belém field) and Rosário Ledge (Felipe Guerra municipality, State of Rio Grande do Norte, Brazil). The analysis of thin sections of carbonate rocks under CL revealed that grains (allochemical or not) and diagenetic products (micritization, dolomitization, neomorphism and cementation) exhibit since absence of luminescence the various luminescence colors (yellow, orange, red, brown, and blue) in a variety of intensities. As pure calcite shows dark blue luminescence, the occurrence of different luminescence colors in calcite crystals suggest one or more punctual crystal defects such as free electron, free space and impurity. The dyeing of thin sections with alizarin and potassium ferrocyanide revealed the absence of ferrous carbonate in the different lithotypes of Jandaíra Formation. Therefore, the different colors and intensities of CL observed in these rocks are probably caused by the presence of ion activators such as Mn2+ and is not an activator/inhibitor combination. In the same way, the absence of luminescence is very probably caused by the absence of activator ions and not due to the low concentration of inhibitor ions such as Fe2+. The incorporation of Mn2+ in the different members of the Jandaíra Formation must have been controlled by the redox state of the depositional environment and diagenesis. Therefore, it is possible that the luminescent members have been formed (e.g.,ooids) or have been modified (gastropod neomorphism) under reduction conditions in the depositional environments, in subsurface during the burial, or, in the case of Rosario Ledge samples , during the post-burial return to surface conditions. As regards the sudden changes from low to moderate and to strong luminescence, these features should indicate the precipitation of a fluid with chemical fluctuations, which formed the frequent zonations in the block cement of the Rosario Ledge samples. This study suggests that the different intensities and colors of CL should be correlated with the Mn2+ and Fe2+ contents, and stable isotopes of samples to determine the salinity, temperature, pH e Eh conditions during deposition

Trabalho, pobreza e caridade: as ações do Padre Ibiapina nos sertões do Nordeste

This work started from an investigation concerning the process of education, moralization and disciplining of the poor in the backlands of the Brazilian Northeast region, in the second half of the 19th century, through the incorporation of the values of productive work. In order to do so, we took as our field of investigation the missions of Father José Antônio Pereira Ibiapina (1806-1883), in which an extensive work was developed, including the construction of twenty two (22) charity houses in the States of Rio Grande do Norte, Paraíba, Pernambuco, Ceará e Piauí, but also of weirs, churches, graveyards, hospitals and so forth. Given the socio-historical character of the research, we adopted qualitative methods of analysis and the following procedures: survey and analysis of documents, statute and internal rules that ordered the workings of the charity houses; biographies on Father Ibiapina and the missions‟ reports, as well as various sorts of publications on the missionary. Our study comprises his 27 year-period of missionary-religious activity (1856-1883), and undertakes an analysis on the topic of poverty, since the medieval Christian take on it until modernity, when it stops representing a value and becomes a problem to be solved through work. The socio-political context in which Ibiapina lived in the Northeast was marked by the consequence of droughts and economic crises in the region. The analysis of the documents indicates that, in the circumstances of political weakness and lack of interest for regional demands by the national political agenda, his missionary actions produced strong effects. Starting from an ethics of valorization of work, which combined modern and traditional elements, his actions set up disciplinary, moralizing and civil educational practices of the poor, founding, simultaneously, a pragmatic religious experience directed at the resolution of the problems caused by poverty. In that sense, we observe that such actions are connected to the broader process of moralization and education of the poor, but the analysis also suggests that their inscription into the social order articulated both forward as well as conservative aspects of the established system

Identidade rural e agricultura familiar :O Pronaf B sob a ótica dos beneficiados

This work has for objective to analyze the perception of benefited of Pronaf B Programa Nacional de Fortalecimento da Agricultura Familiar, in relation to the results that are presented concerning this program. For this, it is presented hypothesis of that the familiar agriculturists, fit in the norms of credit of Pronaf B, have a peculiar perception on the end item of this program, produced from inherent characteristics to the agricultural reality where they live. Ahead of this, I broke myself of estimated of that the searched familiar agriculturists are more socially vulnerable to the inaqualities the agricultural areas. For this research, they had been used, mainly, theoretical reflections of studious of the campesinato, familiar agriculture and of researchers of the impacts of Pronaf B in the agricultural way. The empirical data of the research had been gotten, through the application of questionnaires with the benefited ones and interviews with the mediators of this program in the two searched cities, Apodi and Antônio Martins, in the Rio Grande do Norte, who proportionally withholds the biggest contract number of Pronaf B in the state. The conclusion of the research ratifies the initial hypothesis of that the perception on the results of Pronaf B for benefited its is peculiar, and points stops beyond the economic results, such as: the rise of auto-esteem; the rescue of the citizenship feeling and as impact in autoconsumo of the families of the agriculturists benefited for Pronaf B

Novas fronteiras petrolíferas no Brasil : uma análise da necessidade de nova regulamentação da área do pré-sal sob a ótica constitucional

The Oil industry in Brazil has gone through several stages during the economical, political and social historical process. However, the significative changes have happened in the last fifteen years, due to market opening arising from the relaxation of the state monopoly over the Oil deposits and its derivatives. The edition of the Constitutional Amendment #9, changing the first paragraph of the 177th item of the Federal Constitution, marked the end of a stiffness about the monopoly that the Brazilian state kept in relation to the exploration and research of Oil and Gas. The economical order was fundamental to actualize the idea contained in the #9 Amendment, since its contents has the power to set up measures to be adopted by public power in order to organize the economical relations from a social viewpoint. The new brazilian Oil scenery, called pre-salt, presents itself in a way to amaze the economical markets, in addition to creating a new perspective to the social sector. This work will identify, in this new scenario, the need for change in the legal system. Nevertheless, this subject must not be treated in a thoughtless way: being an exhaustible good, we shall not forget that the future generations also must benefit from the exploration of natural resources recently discovered. The settlement of a new regulatory mark, including the change in the concession contract model to production and sharing is one of the suggested solutions as a bill in the National Congress, in an attempt to ensure the sovereignty of the nation. The constitutionality of a new regulatory mark is questioned, starting from an analysis of the state monopoly, grounding the comprehnsions in the brazilian constitutions, the relevance of the creation of Petrobras for self-assertion of the state about the monopoly of Oil and derivatives, and its posture after the Constitutional Amendment nº 9 (1995), when a company stops having control of the state monopoly, beginning to compete in a fairly way with other companies. The market opening and private initiative are emphasized from the viewpoint of the Constitutional Principles of the Economical and Social Order. The relaxation of the monopoly regarding the exploratory activity in the Federal Constitution doesn't deprive from the Union the ownerships of underground goods, enabling to this federal entity to contract, directly or by concession of exploration of goods, to state-owned or private companies. The existing oil in the pre-salt layer transforms the scenario from very high risk to low risk, which gives the Union the possibility of defining another way of exploring this resources in the best interests of the Public Administration

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

Estudo da recuperação de óleo por drenagem gravitacional assistida por injeção de vapor

Steam assisted gravity drainage process (SAGD) involves two parallel horizontal wells located in a same vertical plane, where the top well is used as steam injector and the bottom well as producer. The dominant force in this process is gravitational. This improved oil recovery method has been demonstrated to be economically viable in commercial projects of oil recovery for heavy and extra heavy oil, but it is not yet implemented in Brazil. The study of this technology in reservoirs with characteristics of regional basins is necessary in order to analyze if this process can be used, minimizing the steam rate demand and improving the process profitability. In this study, a homogeneous reservoir was modeled with characteristics of Brazilian Northeast reservoirs. Simulations were accomplished with STARS , a commercial software from Computer Modelling Group, which is used to simulate improved oil recovery process in oil reservoirs. In this work, a steam optimization was accomplished in reservoirs with different physical characteristics and in different cases, through a technical-economic analysis. It was also studied a semi-continuous steam injection or with injection stops. Results showed that it is possible to use a simplified equation of the net present value, which incorporates earnings and expenses on oil production and expenses in steam requirement, in order to optimize steam rate and obtaining a higher net present value in the process. It was observed that SAGD process can be or not profitable depending on reservoirs characteristics. It was also obtained that steam demand can still be reduced injecting in a non continuous form, alternating steam injection with stops at several time intervals. The optimization of these intervals allowed to minimize heat losses and to improve oil recovery

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.

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

Nem tudo que reluz é ouro: oficinas terapêuticas no cenário da Reforma Psiquiátrica

The purpose of this study is to discuss the therapeutic workshops function, while questioning if they constitute a mechanism for change of the traditional asylum logic. The Psychiatric Reform was materialized with the financing and regulation of alternative services that substitute the psychiatric hospital. This change was promoted by the anti asylum debate and the deinstitutionalization besides psychosocial rehabilitation paradigms. Mental health care, therefore, acquired a new form and the Centers for Psychosocial Care (CAPS) are considered the main services of the health network presently under construction. They are services that offer a variety of therapeutics and amongst them is the workshop, considered essential for the advancement of the Reform ideas. The study was conducted in a CAPS II in Natal, RN. Systematic visits were made using the Institutional Analysis perspective, futhermore were made interviews with professionals who was related to workshops. In the end, data were then discussed according to Schizoanalysis. Results denot that workshops represents, in the same time, progress and regress of Psychiatric Reform. It was observed that workshops were oftentimes reduced to strategies for the occupation of time, and as a means for the transmission of social values considered correct. The relationship between professionals and the user of the service was hierarchical and both players was seeing the workshop as a task to be met. Although users expressed intreresting about wokshops, was reported that the work was boring. Besides, except for some cases, the therapeutic workshops wasn t helping clients to create other possibilites in theirs life and stops the job inside the mental care service

Atividade biológica de células-tronco da polpa de dentes decíduos humanos submetidas à criopreservação

Dental pulp stem cells have been widely investigated because of their ability to differentiate into both dental and non-dental cells, with potential use in therapies involving tissue engineering. The technique of cell cryopreservation represents a viable alternative for the conservation of these cells, since it stops reversibly, in a controlled manner, all of cell biological functions in an ultra low temperature. The present study aimed to evaluate, using in vitro experiments, the influence of a cryopreservation protocol on the biologic acti vity of stem cells from human exfoliated deciduous teeth (SHED). Cells obtained from the pulp of three deciduous teeth on end-stage exfoliation or with indicated extraction were expanded in α-MEM culture medium supplemented with antibiotics and 15% fetal bovine serum. At second subculture (P2), a group of cells were submitted to cryopreservation for 30 days in 10% DMSO diluted in fetal bovine serum, at -80º C, while the remind cells continued under normal conditions of cell culture. Cell proliferation was evaluated in both groups (not cryopreserved or cryopreserved) by Trypan blue stain essay at intervals of 24, 48 and 72h after plating. Cell cycle analysis of SHEDs submitted or not to the cryopreservation protocol was performed in the same intervals. Events related to cell death were studied by Annexyn V and PI expression under flow cytometry at the intervals of 24 and 72h. The presence of nuclear morphological changes was evaluated by DAPI staining at 72h interval. It was observed that both groups exhibited an upward cell proliferation curve, without considerable changes in cell viability throughout the experiment. The distribution of cell in the cell cycle phasis was consistent with cell proliferation in both groups. There were no nuclear morphological damages in the end range of the experiment. therefore, it is concluded that the proposed cryopreservation protocol is efficient for storing the studied cell type, allowing its use in future experimental studies