Características limnológicas e estrutura trófica das comunidades de peixes de alguns lagos naturais e artificiais do Rio Grande do Norte

Artificial lakes must differ from natural lakes in important structural and functional aspects that need to be understood so that these ecosystems can be properly managed. The aim of this work was to test the hypothesis that the artificial lakes (impoundments) in the semi-arid region of the Rio Grande do Norte State are more eutrophic and turbid and have different trophic structure when compared to the natural coastal lakes that occur in the humid eastern coast of the State. To test this hypothesis, 10 natural lakes and 8 artificial lakes with about 100 ha were sampled between September and November 2005 for the determination of some limnological variables and the abundance of the main fish species, which were grouped in three trophic guilds: facultative piscivores, facultative planktivores and omnivores. The results show that the artificial lakes had significantly higher concentrations of total nitrogen, total phosphorus, chlorophyll a , total and volatile suspended solids than the natural lakes. Results also show that the values of pH, total alkalinity, electric conductivity, turbidity as well as the coefficient of vertical attenuation of light were significantly higher in the artificial lakes than in the natural lakes. In the artificial lakes, the abundance of facultative planktivores was significantly higher, while the abundance of facultative piscivores significantly lower than in the natural lakes. There was no significant difference in the abundance of omnivorous fish between the two types of lakes. These results suggest that the increase in turbidity together with the other changes in the water quality of the artificial lakes, modifies the trophic structure of the fish communities reducing the importance of piscivores and the length of the food chains

Avaliação do efeito de particulados sólidos na eficiência de um inibidor de corrosão recomendado para meios salinos com CO2

The main problem on the exploration activity on petroleum industry is the formation water resulted on the fields producing. The aggravating of this problem is correlated with the advancing technologies used on the petroleum extractions and on its secondary approach objecting the reobtainment of this oil. Among the main contaminants of the water formation are corrosives gases such as: O2, CO2 and H2S, some solids in suspension and dissolved salts. Concerning to those gases the CO2 is the one that produce significant damage for carbon steel on corrosion process of the petroleum and gas industries. Corrosion inhibitors for carbon steel in formation water is one of the most used agents in control of those damages. In this context, the poor investigations of carbon steel corrosion proceeding from solids in suspension is an opened field for studies. On this work the inhibitor effect of the commercial CORRTREAT 703 was evaluated on some specific solids in suspension at saline medium containing 10.000 ppm of de-aerated chloride using CO2 until non oxygen atmosphere been present. For that, quartz, calcium carbonate, magnetite and iron sulphide were subjected to this investigation as the selected solids. The effect of this inhibitor on corrosion process correlated with those specific solids, was measured using electrochemical (resistance of linear polarization and galvanic pair) and gravimetrical techniques. During all the experimental work important parameters were monitored such as: pH, dissolved oxygen, temperature, instantaneous corrosion rate and galvanic current. According to the obtained results it was proved that the suspension solids calcium carbonate and iron sulphide decrease the corrosion process in higher pH medium. Meanwhile the quartz and magnetite been hardness increase corrosion by broking of the passive layer for erosion. In the other hand, the tested inhibitor in concentration of 50 ppm, showed to be effective (91%) in this corrosion process

Efeito antibacteriano de tecidos têxteis revestidos por prata através da técnica de deposição por plasma

In this study, it has been investigated the influence of silver film deposition onto 100% polyester woven and non-woven, on the survival of Escherichia coli and Staphylococcus aureus in contact with these surfaces. The treatment was performedin a chamber containing the working gas at low pressure (~ 10-2 mbar). Some process parameters such as as voltage: 470 V; pressure: 10-2 mbar; current : 0.40 A and gas flow: 6 and 10 cm3/min were kept constant. For the treatments with purêargon plasma using a flow of 6 and 10 cm3/min, different treatment times were evaluated, such as, 10 , 20, 30, 40, 50 and 60 minutes. Contact angle (sessile drop), measurements were used to determine the surface tension of the treated fabrics and its influence on the bacteria grow as weel as the possibilities of a biofilm formation. The formation of a silver film, as well as the amount of this element was verified byEDX technique. The topography was observed through scanning electron microscopy (SEM) to determine the size of silver grains formed on the surfaces of the fabric and assess homogeneity of treatment. The X-ray diffraction (XRD) was used to analyze the structure of silver film deposition. The woven fabric treatments enabled the formation of silver particulate films with particle size larger than the non-woven fabrics. With respect to bacterial growth, all fabrics were shown to be bactericidal for Staphylococcus aureus (S. aureus), while for the Escherichia coli (E. coli), the best results were found for the non-woven fabric (TNT) treated with a flow of 10 cm3/min to both bacteria

Potencialidades do uso do blog em educação.

This research is an interpretative analysis of the type participatory research, developed in a qualitative and quantitative use of the blog as a support to a specific discipline, in order to identify the potential evident from its use. The report discusses the changes that have occurred in contemporary society, relating to the development of information technologies and communication (ITC s), presents a brief review of the historical background of the Internet and its use as an aid to education, emphasizing some environments inserted media the Internet, focusing on the main blog - its concept, origin and categorization, and analyzes the concepts of using the blog from the dialogues with teachers and students of pedagogy course at the Federal University of Rio Grande do Norte. Started from the assumption that the use of technological resources, such as blogging, with strictly educational purposes, can extend the knowledge beyond the walls of the classroom, thus creating a dialogic and interactive environment. Using data collected through interviews, questionnaires and observation, we seek to understand the object of study as a supportive environment for the teaching of a subject, raising some theoretical and methodological questions about its application to educational practice, and possible contributions to the construction of knowledge. The results indicate that there are several capabilities that make the blog a space conducive to teaching and learning process, and relates the concepts of the study participants about their use, highlighting the most important places to be solved, so that teachers and students to take ownership of knowledge necessary for capacity building required by the contemporary social context, due to the advancement of science and technology.

Vivências compartilhadas de filhos separados pela hanseníase no RN a luz da história oral de vida

Several epidemics marked the lives of individuals and communities in all historical periods, and a prime example is leprosy, infectious disease marked by stigma, prejudice and social exclusion. In the past, the compulsory isolation of patients with leprosy caused serious social and psychological problems, resulting in the separation and the partial or total disruption of the family relationship. Children deprived of this living, removed often inhumanely, were kept and bred in preventoriums / educational establishments. This study aimed to: rescue the oral history of life of the children of leprosy patients that were built in preventorium Osvaldo Cruz, Natal, Rio Grande do Norte; develop a contextual analysis about these children; know the life trajectory of children of leprosy patients institutionalized in preventoriums / educational establishments; produce a documentary on the history of life of children of parents separated by leprosy; forming MORHAN of Rio Grande do Norte state; and implement the I Meeting of MORHAN of Rio Grande do Norte state. This is an exploratory and descriptive study, with a qualitative approach, approved by the ERC No. 024/024/2012 Liga Norteriograndense Contra o Câncer. We used the contributions of the method and technique of oral history of life as methodological reference. We interviewed 10 individuals egress from preventorium Osvaldo Cruz in Natal/RN, sons of former patients proven to be residents in the city, of both sexes, older than 18, with cognitive, intellectual and emotional conditions preserved. The analysis of the histories obtained from collaborators was performed in the light of Thematic Content Analysis. The results and discussions are presented through two articles which meet the proposed objectives. The first, called Contextual Analysis on the children of leprosy patients in preventoriums aimed to record the phenomenon of children of leprosy patients in preventorium through four contextual levels, which identified the need to broaden the debate on public policy in the field of leprosy as a way to enable more effective measures to propagate in the search for harm reduction and direct consequences resulting from stigma and marginalization around patients and their healthy children, egress from preventoriums. The second, Leprosy and the denial of history: the story of separated children , aimed to know the life trajectory of children of leprosy patients who were institutionalized in preventoriums / educational establishments. In this article, we discuss the research question through the establishment of three main themes: 1. Losses and damages: disintegration and reintegration into the family and denied childhood; 2. Unforgettable: remarkable things you do not forget; and 3. Expectancy in living new situations: in search of other paths and destinations. These thematic axis highlighted the negative implications for the lives of the subjects, arising from the separation of their parents, leprosy patients at the time of compulsory isolation; however, has also been shown that this separation was not decisive in their life histories, once they have succeeded in providing a new sense of these experiences and lead their lives with dignity and fortitude. It was concluded that these children demonstrated resilience as form of defense and fighting stigma and prejudice, being able to reinvent themselves and build new paths and destinations

Estratégia ambiental e agências de viagens e turismo :um estudo sobre a importância de práticas ambientais na escolha de um pacote turístico

The objective of the work was to investigate, from the vision of travel agents, the importance of environmental practices as a decision factor in the purchase of a tourist package. For in such a way, it was established as target population, the travel agencies and tourism linked to he Brazilian Association of Travel agencies ABAV, hearing the Brazilian travel agents that exerted the function in Natal, city in 2005. The election of the sample was accomplished using the simple random sampling technique. The amount of agents effectively searched was of 150 agents being distributed 150 questionnaires, with closed and opened questions, applied during the month of November in 2005. Results showed great variability of interviewed answers in that if it relates for sale of package tourist where the customer demonstrates enviromental concern with the environmental quality. Through multiple regression analyses, it was environmental concern with the environmental quality of the place and the perception of the practical importance of the existence environmental practices in the place as important factor in the decision of tourist package purchase

Fibra de crital fotônico: fundamentação e aplicações

The main purpose of this dissertation, consists of the study and analysis of the PBG (Photonic Band Gap )..tecnology incorporated in optical fiber structures. So, we'l1 present a complete PBG structure theory, and folowing this, we'l1 present also a chapter for convencional optical fiber, due to the need to construct the base theory of them, and latter a more complete work about photonic crystal fiber. Finaly, we'l1 show the results of the signals , dispersion, and obtained curves under the right dimensions according to the required signals, for convencional optical and photonic crystal fiber. Knowing that PBG crystals with low losses act as perfect mirrors for forbidden frequences and knowing that the persence of structures of PBG as substrates, brings some desirable characteristics such as spontaneous emition supression and superficial waves. We' 11 show according to these characteristics its applications in telecomunication. Therefore, the enphasis of this work is to show that the optical fibers are the only practible thing to integrate the enormous quantity of data and video at intemet' s market, developing, manipulating, changing, and multiplexing the optical fibers chanels in an area where we expect that the photonic crystals has an important hole, since the photonic crystals can be projected and made to avoid losses in the bands of certain wavelength which permits the increase in efficiency ofthe optical components projected with crystals. A sequence of this work would be the utilisation of the PBG structures in the new system of optical network without fiber developed by Bell laboratories of the lucent tecnology, last year using light rays for transmiting information through the air. The new system of optical networks without fiber will permit sending the data of 15 cd-rooms in less then one second, what represents 65 times more information than those transmitted through the actual radio frequences

Escravidão na Vila do Príncipe, província do Rio Grande do Norte (1850/1888)

This dissertation presents a study on the slave population of Vila do Príncipe, from 1850 to 1888, based on the judicial and notarial collection of hand written documents as well as on the Reports of Presidents of the Province of Rio Grande do Norte. The issue that drives the research relates to the reproduction of slavery in a region of cattle breeding colonization. Therefore, the research aims to understand how in a peripheral socio-economic place (in Vila do Príncipe, cattle breeding Seridó) after the prohibition of the African slave trade, the slave relationships subsisted and structured themselves. In the sense, the research analyzed the dynamics of socio-economic slave units and their relationship with space, ownership structure and the slave family.