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Search Results: 1 - 10 of 404139 matches for " Alan Eduardo R. de Freitas "
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The Use of Sodium Silicate as a Corrosion Inhibitor in a Saline Drilling Fluid: A Nonaggressive Option to the Environment  [PDF]
Fernando B. Mainier, Anne A. M. Figueiredo, Alan Eduardo R. de Freitas, André Armando M. de Alencar Junior
Journal of Environmental Protection (JEP) , 2016, DOI: 10.4236/jep.2016.713157
Abstract: The function of a corrosion inhibitor in drilling mud compositions is the corrosion protection of the equipment involved in drilling operations. Many compositions involve environmentally several products such as fatty amines of high molecular weight, polyoxylated amines, amides, imidazolines, nitrogen heterocyclic products, etc. The potential advantages of the use of silicates are the effective protection of carbon steel, especially in aerated saline fluids, low costs and non-aggressive behavior to environment. Gravimetric and electrochemical tests were carried out using an aerated solution of 3.5% NaCl and the addition of sodium silicate (Na2SiO3·9H2O) as a corrosion inhibitor at concentrations of 250 to 2000 mg/L. The efficiencies of the corrosion protection of carbon steel using silicate concentrations greater than 1250 mg/L were greater than 92%.
Etnobotanica e etnozoologia em unidades de conserva??o: Uso da biodiversidade na apa de genipabu, Rio Grande do Norte, Brasil
Torres,Denise de Freitas; de Oliveira,Eduardo Silva; Alves,R?mulo Romeu da Nóbrega; Vasconcellos,Alexandre;
Interciencia , 2009,
Abstract: the sustainable use of natural resources by local populations must be based on an understanding of the relationships between humans and their environment. in this context, the present study analyzed aspects of the interactions between human populations and the biodiversity found in the genipabu environmental protection area (apa-genipabu), coast of the state of rio grande do norte, brazil. a total of 60 open interviews were carried out in three communities established within the apa-genipabu, with questions designed to inquire aspects of their general perception of the area and their knowledge and use of the local biodiversity. approximately 82% of the residents do not fully understand the concepts behind creating a conservation area. the interviewees identified 97 plants species (belonging to 48 families) and 172 animals (131 vertebrates and 41 invertebrates), including three animal species considered endangered in brazil. useful species were most often cited. among the positive perceptions of the apa-genipabu, interviewees cited the importance of preserving the sand dunes, animals, plants and lakes, and maintaining the natural landscape to attract tourism. in order to improve conservation strategies in the protection area it will be important to build on the positive aspects of the reserve that were cited by the local population and provide these people with more information about its conservation goals.
Efeito da qualidade da água no ciclo de vida e na atra??o para oviposi??o de Aedes aegypti (L.) (Diptera: Culicidae)
Beserra, Eduardo B;Fernandes, Carlos R M;Sousa, José T de;Freitas, Eraldo M de;Santos, Keliana D;
Neotropical Entomology , 2010, DOI: 10.1590/S1519-566X2010000600026
Abstract: the present research aimed at evaluating the influence of the water quality in the life cycle and attraction of aedes aegypti (l.) females to oviposit using different sources of water (raw sewage, effluent of uasb reactor, effluent of polishing lagoon, effluent of anaerobic filter, rain water and de-chlorinated water). the immature development time and survivorship were evaluated on a daily basis in two distinct feeding systems (with and without food). the quality of the water was shown to affect the egg and larval stages, but not the pupal or the adult. in the absence of food, no development was observed in rain water and de-chlorinated water. immature development was faster in water sources from raw sewage, although with the lowest survivorship (37.3%). free-choice tests indicated that females preferred to lay most of their eggs on water collected from the effluent of a uasb reactor, achieving the highest oviposition activity index (oai) of 0.57. in non-choice tests, females laid larger batches of eggs in water collected from anaerobic filters (204.8 eggs), with the lowest number of eggs being laid on de-chlorinated water (37.3 eggs). it can be concluded that a. aegypti does not demonstrate any particular preference to lay eggs on clean water. this has serious implications for developing strategies to manage populations of this important vector in urban areas as it was shown to lay eggs and successfully develop on several different sources of water.
Ciclo de vida de Aedes (Stegomyia) aegypti (Diptera, Culicidae) em águas com diferentes características
Beserra, Eduardo B.;Freitas, Eraldo M. de;Souza, José T. de;Fernandes, Carlos R. M.;Santos, Keliana D.;
Iheringia. Série Zoologia , 2009, DOI: 10.1590/S0073-47212009000300008
Abstract: the present work aimed to estimate the effect of water quality in the development of aedes aegypti (linnaeus, 1762). the life cycle of this vector was studied in raw sewage water, effluent of uasb reactor, effluent of polishing lagoon, effluent of anaerobic filter, rainwater and de-chlorinated water. the development period, egg viability and larval and pupal survival were evaluated daily as well as the adult longevity and fecundity. the duration of larval period showed a variation of 5.6 to 9.1 days. survival was considered low in raw sewage water, effluent of uasb reactor, effluent of polishing lagoon and effluent of anaerobic filter. no difference in terms of the duration and egg and pupal viability nor in the adult longevity and fecundity was detected. it was verified that despite a reduction in larval viability, a. aegypti could accomplish total development in waters with high pollution degree and that all the treatments were suitable to the development of this vector.
O suicídio em Portugal no séc. XX: elementos em píricos para a pesquisa
Eduardo de Freitas
Finisterra - Revista Portuguesa de Geografia , 1982,
Compara??o dos valores de desgaste abrasivo e de microdureza de 13 resinas compostas usadas em odontologia através do método do disco retificado
Bianchi, Eduardo C.;Aguiar, Paulo R. de;Alves, Manoel C. S.;Freitas, César A. de;Rodrigues, Ana R.;Carvalho Jr., Oscar B. de;
Polímeros , 2007, DOI: 10.1590/S0104-14282007000200012
Abstract: it is now commonplace to search for methods to assess the useful lifetime of dental restorations made of resins, which are quicker and less subjective than clinical analyses. with this purpose, this work presents a new methodology based on the grinding disk for evaluating the abrasive wear of composed resins. resistance tests to the abrasive wear were made with 13 composed resins used as dental material, and a comparison was done with the hardness of those resins. from the data analysis, we concluded that the method of rectified disks is efficient for obtaining the resistance to the abrasive wear. furthermore, the correlation between hardness and abrasive wear was very small, which indicates that each composed resin has its own characteristics and that the wear also depends on other factors.
Relacionamento de diferentes domínios da atividade física habitual com indicadores de risco cardiovascular em adultos jovens do sexo masculino
Freitas Júnior, Ismael Forte;Rodrigues, Eduardo Quieroti;Sousa, Sergio de;Campos, Eduardo Zapaterra;Fernandes, R?mulo Araújo;Casonatto, Juliano;Balikian Júnior, Pedro;
Motriz: Revista de Educa??o Física , 2010, DOI: 10.5016/1980-6574.2010v16n3p591
Abstract: objectives: to analyze different physical activities domains in healthy adults and correlate with cardiovascular risk factors. methods: the sample was composed by 32 physical education undergraduate students, with mean age of 22.6 years old. adiposity was assessed by waist circumference (wc), body mass index (bmi) and bioelectrical impedance. additionally, fast glucose (10-12 hours), systolic (sbp) and diastolic (dbp) blood pressure were assessed. physical activity level was assessed by questionnaire (baecke et al., 1982). results: sports activities and leisure time were not related with cardiovascular risk factors. however, job activities were negatively related with %bf, sbp and dbp. conclusion: different physical activity domains should be considered when analyzing its associations with health indicators.
Compara??o da influência entre tempos de polimeriza??o em resinas compostas polimerizadas com LED e Luz Incandescente
Ulhoa, Michele P. M.;Santana, Lúcio R. S.;Bianchi, Eduardo C.;Cruz, Carlos E. D.;Aguiar, Paulo R.;Freitas, César A. de;Freitas, Márcia F. A. de;
Polímeros , 2007, DOI: 10.1590/S0104-14282007000300017
Abstract: the purpose of this work was to compare polymeric dental resins cured with halogen lamp and with light emission diode (led) devices, using the grinding disk method customized for dentistry and the corresponding microhardness values. tests were carried out on resin samples of five brands, which were cured for 10, 20 and 40 s with the two devices. the analysis of microhardness and aggressiveness has allowed us to conclude that there is no correlation between these properties. in microhardness tests, the material heterogeneity has produced relative high standard deviation values and has not shown statistical differences between the analyzed samples. in the statistical analysis for the results with the grinding disk method, the resin with highest wear was the tetric ceram, cured with led device for 10 s (aggressiveness average 0.170 mm3/n.m ). the composite resin with least wear was charisma, cured with halogen lamp device for 20 s (aggressiveness average 0.057 mm3/n.m ).
Update of the Chronology of Natural Signals in the Near-Surface Mean Global Temperature Record and the Southern Oscillation Index  [PDF]
Chris R. de Freitas, John D. McLean
International Journal of Geosciences (IJG) , 2013, DOI: 10.4236/ijg.2013.41A020

Time series for the Southern Oscillation Index and mean global near surface temperature anomalies are compared for the 1950 to 2012 period using recently released HadCRU4 data. The method avoids a focused statistical analysis of the data, in part because the study deals with smoothed data, which means there is the danger of spurious correlations, and in part because the El Ni?o Southern Oscillation is a cyclical phenomenon of irregular period. In these situations the results of regression analysis or similar statistical evaluation can be misleading. With the potential controversy arising over a particular statistical analysis removed, the findings indicate that El Nino-Southern Oscillation exercises a major influence on mean global temperature. The results show the potential of natural forcing mechanisms to account for mean global temperature variation, although the extent of the influence is difficult to quantify from among the variability of short-term influences.

Empreendimentos induzidos por políticas públicas: reflex?es a partir do Programa de Combate à Pobreza Rural (PCPR) em Minas Gerais
Freitas, Alair Ferreira de;Freitas, Alan Ferreira de;
Intera??es (Campo Grande) , 2011, DOI: 10.1590/S1518-70122011000200012
Abstract: the goal of this work is to reflect on sustainability ventures induced by public policies and programmes, by reference to empirical programme of combating rural poverty of the government of minas gerais (pcrp). the analyses demonstrate that many businesses find themselves without the mobilization and social integration required for its sustainability. the pcrp needs qualify systematically processes and planning of the demands of family farmers to promote ownership of the project to be deployed and avoid the formality of ventures.
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