17 resultados para Rudolf Schwarz

em Universidade Federal do Rio Grande do Norte(UFRN)


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ALVES, Janaína da Silva. Análise comparativa e teste empírico da validade dos modelos CAPM tradicional e condicional: o caso das ações da Petrobrás. Revista Ciências Administrativas, Fotaleza, v. 13, n. 1, p.147-157, ago. 2007.

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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

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Methomyl (Lannate®) is an insecticide from the carbamate group, frequently used in pest control in various types of crops. This compound works inhibiting the activity of the enzyme acetylcholinesterase. The use of physicochemical and ecotoxicological analysis is the most efficient strategy for the correct characterization and control of residues of metomil. The main objectives of this study were to evaluate the acute toxicity of methomyl in 96 hours of exposure and, through a sublethal assay of 5 hours, to assess its effect on the activity of acetylcholinesterase present in brain and squeletic dorsal muscle of the Danio rerio fish. The results showed that the LC50-96 found to D. rerio was 3.4 mg/L and it was found through the average of four definitive tests. In vitro assays were used to test the inhibitory action of methomyl directly over soluble AChE, extracted from the squeletic dorsal muscle, with maximum inhibition of 68.57% to the insecticide concentrations of 0.2 mg/L. In sublethal tests with D. rerio, inhibitory effect of methomyl was found over the soluble form of AChE in the squeletic dorsal muscle, both in one and five hours of fish exposure to the insecticide. In both period, the average values of inhibition were around 61%. In the same condition, no significant inhibitory effect of methomyl soluble and membrane AChE of the D. rerio was observed in the 0.42, 0.85, 1.70 and 2.50 mg/L concentrations and in both times of fish exposure

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The use of biofuels remotes to the eighteenth century, when Rudolf Diesel made the first trials using peanut oil as fuel in a compression ignition engine. Based on these trials, there was the need for some chemical change to vegetable oil. Among these chemical transformations, we can mention the cracking and transesterification. This work aims at conducting a study using the thermocatalytic and thermal cracking of sunflower oil, using the Al-MCM-41 catalyst. The material type mesoporous Al-MCM-41 was synthesized and characterized by Hydrothermical methods of X-ray diffraction, scanning electron microscopy, nitrogen adsorption, absorption spectroscopy in the infrared and thermal gravimetric analysis (TG / DTG).The study was conducted on the thermogravimetric behavior of sunflower oil on the mesoporous catalyst cited. Activation energy, conversion, and oil degradation as a function of temperature were estimated based on the integral curves of thermogravimetric analysis and the kinetic method of Vyazovkin. The mesoporous material Al-MCM-41 showed one-dimensional hexagonal formation. The study of the kinetic behavior of sunflower oil with the catalyst showed a lower activation energy against the activation energy of pure sunflower oil. Two liquid fractions of sunflower oil were obtained, both in thermal and thermocatalytic pyrolisis. The first fraction obtained was called bio-oil and the second fraction obtained was called acid fraction. The acid fraction collected, in thermal and thermocatalytic pyrolisis, showed very high level of acidity, which is why it was called acid fraction. The first fraction was collected bio-called because it presented results in the range similar to petroleum diesel

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The relationship between lipid peroxidation, antioxidant defense and diabetic osteopenia remains unclear. This study evaluated the relationship between lipid peroxidation index, antioxidant defense parameter and bone metabolism in a premenopausal diabetic model by measurements such as thiobarbituric acid-reactive substances concentration (TBARS) and reduced glutathione (GSH) content in brain homogenates, histomorphometric analysis, biomechanical testing and bone mineral density (BMD). Female Wistar rats with regular estrous cycle were divided into two groups: Group 1: control rats (n = 15) and Group 2: diabetic rats (n = 15). Diabetes mellitus was induced by alloxan and confirmed by glycemia 250 mg/dL. The experimental period understood 1 and 5 after days induction and 45, 75 and 120 days after the installation of diabetes mellitus.The lipid peroxidation index, measured by TBARS concentration, showed a significant increase (p<0.05) in diabetic animals in comparison to animals control. However, the antioxidant parameter, measured by GSH content, was significantly decrease (p<0.05) in diabetic animals. Histomorphometric analysis showed a significant increase (p<0.05) in femoral trabecular separation together with a significant decrease (p<0.05) in trabecular thickness and reduced trabecular bone volume in diabetic rats. Moreover, biomechanical testing and BMD values were significant decrease (p<0.05) in diabetic group. Thus, our results demonstrated that increased lipid peroxidation and altered antioxidant defense could be related to the development of oxidative stress and diabetic osteopenia in premenopausal rats

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The ethanol is the most overused psychoactive drug over the world; this fact makes it one of the main substances required in toxicological exams nowadays. The development of an analytical method, adaptation or implementation of a method known, involves a process of validation that estimates its efficiency in the laboratory routine and credibility of the method. The stability is defined as the ability of the sample of material to keep the initial value of a quantitative measure for a defined period within specific limits when stored under defined conditions. This study aimed to evaluate the method of Gas chromatography and study the stability of ethanol in blood samples, considering the variables time and temperature of storage, and the presence of preservative and, with that check if the conditions of conservation and storage used in this study maintain the quality of the sample and preserve the originally amount of analyte present. Blood samples were collected from 10 volunteers to evaluate the method and to study the stability of ethanol. For the evaluation of the method, part of the samples was added to known concentrations of ethanol. In the study of stability, the other side of the pool of blood was placed in two containers: one containing the preservative sodium fluoride 1% and the anticoagulant heparin and the other only heparin, was added ethanol at a concentration of 0.6 g/L, fractionated in two bottles, one being stored at 4ºC (refrigerator) and another at -20ºC (freezer), the tests were performed on the same day (time zero) and after 1, 3, 7, 14, 30 and 60 days of storage. The assessment found the difference in results during storage in relation to time zero. It used the technique of headspace associated with gas chromatography with the FID and capillary column with stationary phase of polyethylene. The best analysis of chromatographic conditions were: temperature of 50ºC (column), 150ºC (jet) and 250ºC (detector), with retention time for ethanol from 9.107 ± 0.026 and the tercbutanol (internal standard) of 8.170 ± 0.081 minutes, the ethanol being separated properly from acetaldehyde, acetone, methanol and 2-propanol, which are potential interfering in the determination of ethanol. The technique showed linearity in the concentration range of 0.01 and 3.2 g/L (0.8051 x + y = 0.6196; r2 = 0.999). The calibration curve showed the following equation of the line: y = x 0.7542 + 0.6545, with a linear correlation coefficient equal to 0.996. The average recovery was 100.2%, the coefficients of variation of accuracy and inter intra test showed values of up to 7.3%, the limit of detection and quantification was 0.01 g/L and showed coefficient of variation within the allowed. The analytical method evaluated in this study proved to be fast, efficient and practical, given the objective of this work satisfactorily. The study of stability has less than 20% difference in the response obtained under the conditions of storage and stipulated period, compared with the response obtained at time zero and at the significance level of 5%, no statistical difference in the concentration of ethanol was observed between analysis. The results reinforce the reliability of the method of gas chromatography and blood samples in search of ethanol, either in the toxicological, forensic, social or clinic

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Alcohol is one of the few psychotropic drugs that their consumption has admitted legally and sometimes encouraged by the society. Studies show alcohol as the highest consumption of drugs among young people and society in general, probably because of its availability and easy access. The abuse causes public health problems, which was closely related to the violence, socioeconomic problems and the high number of automobile accidents. Transit is one of the main sectors affected by the effects of alcohol, observing a high incidence in the studies. About half of automobile accidents occurs after the consumption of alcoholic beverage, and the vast majority of cases related to high concentrations of alcohol in the bloodstream. The relationship of drunk with traffic accidents is in fact evident everywhere in the world, including Brazil, where studies have shown a high relationship between alcohol consumption and traffic accidents. This study determined the alcohol in fatal victims of traffic accidents in the state of Rio Grande do Norte and established the profile of this population compared with those found in Brazil and other countries. Samples of blood of ethanol added to fulfillment of the standardization of chromatographic conditions and procedures for the analysis, being employed in the determination of alcohol in blood samples of 277 victims of traffic accidents, collected at the Institute of Scientific Technical Police of Rio Grande do North (ITEP) in the year 2007. The blood alcohol level was determined in these samples correlated with the sex, age and marital status of the victim and the location, day of week and month when the accident occurred, is doing a statistical analysis and outlining a profile of the victims of an accident at transit in the state of Rio Grande do Norte. The parameters of standardization studied ensured the quality of the analytical method and, consequently, to obtain reliable laboratory results. Being given the best temperature for injector (150 ºC), detector (250 ºC) and column (50 ºC) with a flow of gas in the column of 2mL/minutos and analysis of time of 12 minutes. The method was linear in the range of 0.01 to 3.2 g / L (r2 = 0.9989) with average recovery of 100.2% and precision with coefficient of variation less than 15%. The analysis carried out on victims of fatal road traffic accidents, ethanol detected in the blood in 66.43% of the victims and these, 96% showed concentration ≥ 0.2 g / L, 87.73% of victims were male, while 12.27% female. The younger age group (1535 years) was the most involved (52,35%) and most single (55.60%). The accidents occurred with greater prevalence in the day on Monday (27%) followed by Sunday (24,19%) and Saturday (15,52%) and it was found that the prevalence of injuries varied between the different months of the year, and in February (14.4%) and April (10.47%) the months that had a higher number of accidents, however this oscillation showed no statistically significant difference. Also no significant difference was observed between the tracks of concentration found in men and women. The standardized method showed to be efficient, given satisfactorily to the goals of this work, and the high levels of alcohol found in victims of fatal road traffic accidents are consistent with several studies of literature, and the profile of the victim also supported by presenting in its most young adults, male and single

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Panax ginseng CA Meyer (Araliaceae) is a herbaceous plant widely used in China, South Korea, Japan and other Asian countries for the treatment of various diseases micro circulatory, cerebrovascular, among others, representing one of the drugs used by older man. It has over 30 biologically active ginsenosides with different pharmacological and behavioral effects and inhibitory effect on the NMDA receptor. The amino acid glycine is a co-agonist of the NMDA receptor, activating this receptor. At the cellular level, ketamine is widely known to be NMDA receptor antagonist. The aim of this study was to evaluate the general activity in the open field, and anxiety in elevated plus maze, mice treated with P. ginseng compared with the action of ketamine and glycine, to better understand the action of this herbal medicine at the NMDA receptor. We used 66 adult male rats were divided into six groups: a positive control, treated for 30 days with water by gavage, who received glycine (500mg/kg; po) on days 7, 14, 21 and 28 of treatment, one hour before of behavioral assessment, a negative control was treated for 30 days with water by gavage received ketamine (5mg/kg, ip) on days 7, 14, 21 and 28 of treatment, one hour prior to behavioral evaluation, three experimental groups, receiving 100, 200 or 300 mg / kg P. ginseng by gavage for 30 days and one group treated solely with white water, and is also administered 1 ml of water by gavage one hour prior to behavioral evaluation. Animal behavior in these three groups was also examined on days 7, 14, 21 and 28 of treatment. On day 30 of treatment, the animals were anesthetized with thiopental (70mg/kg) for blood collection and after euthanasia, withdrawal of various organs. There were no changes in weight and body weight gain and weight reasons in organ / body weight. However the consumption of water and food values showed a significant increase. Serum levels of AST was increased in a dose-dependently in the animals treated with doses of P. ginseng, glycine and ketamine as compared to the blank group. Unlike creatinine levels proved to be decreased in all treated groups when compared with white. However, the level of urea in these groups was reduced and no changes were observed in the ALT parameter. Histopathological examination revealed no changes in cell morphology in different tissues. There were no behavioral changes in the elevated plus maze and few changes were observed in the open field, animals treated with P. ginseng, glycine and ketamine when compared to white. These data suggest that the doses of P. ginseng employed were unable to induce general toxicity in rats treated for 30 days and also shows that the general behavior of mice treated with P. ginseng was slightly different from that observed in animals treated with ketamine and glycine. Finally, the study on the elevated plus maze showed that the extract of P. ginseng showed no anxiolytic or anxiogenic action

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This production is a reflection about the practices/experiences involving the teaching of the dance developed by the teachers in the Núcleo de Educação Infantil (NEI/UFRN), with the children from 2 to 7 years old, having as objectives: describe and interpret the lived experiences with the dance focusing on the meaning of the dance and organization of the pedagogic job, identify blanks in the pedagogic practices of dance and appoint possible perspectives to the teaching of dance on the infant education. The way from the investigation has begun with the following question: Who do the teachers understand the dance and live it on the Núcleo de Educação Infantil? The research of phenomenological orientation toke as methodological reference the qualitative approach from the placed phenomenon type, this one has as beginning the interest on the phenomenon by the way as it happens on the lived experience from where comes the knowledge with we can present about the world, trying to interpret it, understand it on its essence/existence. The interviews showed that the researched subjects give to the dance different meanings and consequently present variations on the manner to organize the work around this knowledge. The most of the teachers recognizes the dance as a culture expression, being a priority on the school the job with the folkloric dances. They recognize too the dance as knowledge/content coming from the Arts and Physical Education areas and its relation with the knowledge from others areas on the pedagogic action. There were found different process on the way to conduct the job with the dance in relates from experiences done with dance at NEI and, therefore, of teach/learn this knowledge. Its perceptible that exists a systematic work with the objective of develop the dance and its various educative possibilities, starting from the research about its origins, the exploration of the movement, the contextualization until the artistic practice. Those possibilities are reinforced on the school s curricular propose. Some experiences have as a priority the free expression, the dance s vision without context or the reproduction of movements as stand manners of teaching dance, situations like those observed on the investigation as products from the blanks on the academic formation from the teachers with must be fixed. The interpretation of the experiences with dance, described by the teachers from NEI, connected with the theoretical referential from the investigation, allowed to appoint three perspectives to the work with dance in the infant education, having as main interlocutors Merleau-Ponty and Rudolf Laban: the dance as the body s language; the dance and its movement factors; imitate, improvise and play: manners of draw ways to dance. On those process are emphasized the dance on the scholar context, the elements that constitute this language and the forms of appropriate from it supported in a ludicrous, poetic and educative vision, having as focus the children s education on its peculiarities and possibilities

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This work presents techniques used to design and manufacture microstrip patch antennas for applications in portable and mobile devices. To do so, are evaluated several factors that can influence the performance of microstrip patch antennas. Miniaturization techniques are studied and employed in order to apply this type of antenna in mobile and / or mobile. The theories of microstrip patch antennas are addressed by analyzing characteristics such as constitution, kinds of patches, substrates, feeding methods, analysis methods, the main advantages and disadvantages and others. Techniques for obtaining broadband microstrip patch antennas were surveyed in literature and exemplified mainly by means of simulations and measurements. For simulations of the antennas was used the commercial software . In addition, antenna miniaturization techniques have been studied as a main concern the fundamental limits of antennas with special attention to electrically small antennas because they are directly linked to the microstrip patch antennas. Five design antennas are proposed to demonstrate the effectiveness of techniques used to obtain the microstrip patch antennas broadband and miniaturized for use in mobile devices and/or portable. For this, the proposed antennas were simulated, built and measured. The antennas are proposed to be used in modern systems of wireless communications such as DTV, GPS, IEEE 802.16, IEEE 802.11, etc. The simulations of the antennas were made in business and computer programs. The measured results were obtained with a parser Vector of networks of the Rhode and Schwarz model ZVB 14

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This work presents a theoretical and experimental analysis about the properties of microstrip antennas with integrated frequency selective surfaces (Frequency Selective Surface - FSS). The integration occurs through the insertion of the FSS on ground plane of microstrip patch antenna. This integration aims to improve some characteristics of the antennas. The FSS using patch-type elements in square unit cells. Specifically, the simulated results are obtained using the commercial computer program CST Studio Suite® version 2011. From a standard antenna, designed to operate in wireless communication systems of IEEE 802.11 a / b / g / n the dimensions of the FSS are varied to obtain an optimization of some antenna parameters such as impedance matching and selectivity in the operating bands. After optimization of the investigated parameters are built two prototypes of microstrip patch antennas with and without the FSS ground plane. Comparisons are made of the results with the experimental results by 14 ZVB network analyzer from Rohde & Schwarz ®. The comparison aims to validate the simulations performed and show the improvements obtained with the FSS in integrated ground plane antenna. In the construction of prototypes, we used dielectric substrates of the type of Rogers Corporation RT-3060 with relative permittivity equal to 10.2 and low loss tangent. Suggestions for continued work are presented

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The present work objective to study the configurations that the hinterland it acquires in the workmanship Great hinterland: trails, of Guimarães Rosa demonstrating as this author humanize this element, conferring to it characters universal mystics and through investigations, uncertainties, the auto-corrections of Riobaldo that become hinterland a metaphor of the human interior. Three are the chapters, that they will guide this work: the chapter 1 presents as element key for characterization of the epic one in Great hinterland: trails, the mining hinterland replete of trails, palco of exuberant vegetation, huge and multidimensional scene, where it has an entrecruzamento of fiction and reality. It retakes quarrel of critics as Manuel Cavalcanti Proença, Roberto Schwarz, on the existing epic character in the Great hinterland: trails, constructed from deriving myths of the universal culture, that they had been become popular. The brave and gracious knight, that it has its representabilidade in the popular culture. Thus the medieval hero, the knight represented for the Riobaldo personage, it is cognominado by Proença as Don Riobaldo of the Urucuia, knight of the general fields. O chapter 2 is a study on the popular culture in Rosa and Cascudo. Cascudo the example of Rosa also is exímio studious of the brazilian life, the regionalization and the popular manifestations proceeding from other cultures. O chapter 3 it has as focus of analysis two mitopoéticas personages: Diadorim e Luzia-Homem, which in the cited narratives they generally they assume functions generally atribute the men. Since children, if they dresses male. Valley to point out that Diadorim is not characterized as man, since in Great hinterland:trails if trajaq always as gunman. Luzia, when complete 18 anos pass if to dress as woman, but the stigma of male and female, inherited of the time where it coexisted the father folloies it for all the life. They suffer pain to have been born to fight and to não conhecer to love. They die you deliver the God. This study detects exactly that Diadorim and Luzia-Homem, are personages associates the myths of the universal culture and popular (sphinx, Jellyfish, Venus, Mother d water), that they possess similarities n the archetypes, that transit between the sexos masculine and feminine, without any sexual connotation, possesss it proper code of honr, of this not abdicating ahead of the death. Parallel, in this chapter two cascudianas workmanships willbe studies, that contemplate thematic of the dressed woman of man and being the woman without disguice: the enchantment tale Maria Gomes and romance Flower of tragics romances. The first one will be revisited in order to present subject in Great hinterland:trails through the Diadorim personage. As it will discourse on cases of brave women, cited for Cascudo, immortalized for the tradition, who had made history, that already is not disfarçam of men to carry through acts of bravery and honor.

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The objective of this paper is to analyze the work of the American writer Nathaniel Hawthorne (1804 - 1864), The Scarlet Letter (1850), in the light of the contributions of Literature and History of the American people in the context of New England. Accordingly, we highlight aspects that justify the inclusion of the work as a historical novel, especially based on the reading of The Historical Novel (1936-37) written by Georg Lukács. The diversity of voices and social interrelationships that come out of the main characters of the plot of the novel, as well as their contextual buildings, constituted as important traces to understanding the novel as being of historical value. During our study, we found out that it is in the plots of the novels that the characters reflect, at the same time, the specific conditions of their singularities, the general trends of the historical process and the social conditions from which they arise. We also could see that it is in their singularities that lie special tendencies of human beings. Our references to this study came from scholars as Howard (1964), Bakhtin (1998), Eagleton (2006), Todorov (2009), Zabel (1947), Sellers (1985), Cunlife (1986), Candido (1993) and Schwarz (1981)

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The present work makes some comments on the scattered productions of Gilberto Freyre and Luís da Câmara Cascudo, in the period which includes the early years of their intellectual performance, the second decade of the twentieth century. The corpus of the research is delimited on the texts published by Gilberto Freyre, from 1918 to 1926, which were gathered in the book Tempo de aprendiz (1979), and from the ones published by Câmara Cascudo in Natal local newpapers, such as A Imprensa and A República, in 1924, 1927, 1928 and 1929. Concerning Câmara Cascudo s texts, the delimitations of these years is due to they had a relevant importance for the literary and cultural history of Rio Grande do Norte. The included discussions in these writers texts mainly happen around the modernist and regionalist ideas that happened restrictively in the Northeast region of Brazil, and are based on the relationships between literature and culture. Thus, the set of collaborations of both writers is useful as a sample of the intellectual thinking of the mentioned region. Besides, it is representative in the way the cultural debate got along in the country, which in turn, demanded the inclusion of the local realities in order to follow the renewing process of the worldwide thinking, and as matter of fact, arrange a new process in the Brazilian literary tradition. In this way, the study goals to set the positions taken by the two writers faced to the new challenges that the Brazilian reality of that moment was imposed on. The theoretical basis of this work is focused on the accumulated studies about the Brazilians modernism, regionalism and literature, pointing out the Candido s texts, (2006, 2004, 2002, 1995, 1993 and 1989), Schwarz s (1999, 1997a and 1997b), Perrone- Moysés s (2007), Pallares-Burque s (2005), Azevedo s(1996), D Andrea s (1992), Araújo s (2006, 1998, 1997 and 1995), among other authors. Therefore, It is relevant the participation of both writers in that moment which highlights the renewing of the national thinking and the formation of the Brazilian cultural modernity, even the positions taken by them reveal, at times, different views concerning literature and tradition without being disagreeing, however