Síntese e caracterização do líquido iônico tetrafluoroborato de 1-metil-3-(2,6-(S)-dimetiloct-2-eno)-imidazol como eletrólito para produção de hidrogênio via eletrólise da água

Ionic liquids (ILs) are organic compounds liquid at room temperature, good electrical conductors, with the potential to form as a means for electrolyte on electrolysis of water, in which the electrodes would not be subjected to such extreme conditions demanding chemistry [1]. This paper describes the synthesis, characterization and study of the feasibility of ionic liquid ionic liquid 1-methyl-3(2,6-(S)-dimethyloct-2-ene)-imidazole tetrafluoroborate (MDI-BF4) as electrolyte to produce hydrogen through electrolysis of water. The MDI-BF4 synthesized was characterized by thermal methods of analysis (Thermogravimetric Analysis - TG and Differential Scanning Calorimetry - DSC), mid-infrared spectroscopy with Fourier transform by method of attenuated total reflectance (FTIR-ATR), nuclear magnetic resonance spectroscopy of hydrogen (NMR 1H) and cyclic voltammetry (CV). Where thermal methods were used to calculate the yield of the synthesis of MDI-BF4 which was 88.84%, characterized infrared spectroscopy functional groups of the compound and the binding B-F 1053 cm-1; the NMR 1H analyzed and compared with literature data defines the structure of MDI-BF4 and the current density achieved by MDI-BF4 in the voltammogram shows that the LI can conduct electrical current indicating that the MDI-BF4 is a good electrolyte, and that their behavior does not change with the increasing concentration of water

Nas asas de Ícaro: uma análise da Pedagogia Freinet do 2º ao 5º ano do Ensino Fundamental na perspectiva da ação docente continuada

Célestin Freinet was one of the most memorable educators of the twentieth century. He presented some educational alternatives that had the objective of stimulating the construction of pedagogic actions to promote the social development of the student based upon a work centered on the free expression as the way to self-structure the knowledge. With a permanent proposal of research based on the enquiry-based learning, Freinet set human capacity (cognitive, social-affective, psychometrical) taking cooperation in consideration on the processes of knowledge construction. Based on this referential, this present work has the objective to show Freinet s pedagogy in a continuous teaching action from 2nd to 5th grade focusing the teacher s discourse and also the educative practice of the students of a city public school in Natal. The observed work revealed the teacher s discourse and educative experience and delineated the students development while immersed into Freinet s educational practice. By virtue of the nature and specificity of the theme that guided our research, we chose a qualitative approach to it, as a way of conducting ourselves during our investigative process. We observed and analyzed the method that was used to conduct the activities in the classroom, as well as the ways of expression that the children used through drawings, words (oral text), or through writing. We highlight, among the written texts, the individual and collective texts, and also letters and notes, which during some moments served as a base to express a diversity of languages. The results, after a analyzing the research data, point towards a teaching practice that favors the construction of a significant learning process through the grasping of the school environment, on which all these factors are based: society, knowledge acquisition, abilities, attitudes and values. This learning process also strengthens human solidarity bonds and mutual tolerance, on which the student s social life is seated.

Síntese e caracterização de compostos de coordenação do Ácido 4-cloro-2-(2- furilmetilamino)-5- sulfamoil-benzóico com os íons níquel, cobalto e zinco

This work aimed to promote the synthesis, characterization and propose a plausible molecular structure for coordination compounds involving furosemide (4-Chloro-2-(2- furylmethylamino)-5-sulfamoyl-benzoic acid) with the metal ions Ni+2, Zn+2 and Co+2. The compounds were obtained in methanoic medium by evaporation of the solvent after the synthesis procedure. For characterization of coordination compounds determining the levels of metals by EDTA complexometry, infrared spectroscopy (FTIR), solubility of compounds in various solvents, thermogravimetry (TG), differential scanning calorimetry (DSC), differential thermal analysis were made (DTA), determination of the carbon , hydrogen and nitrogen (CHN). The results of infrared spectroscopy in the region suggest that the organic ligand is coordinated in a bidentate fashion to the metal ions, the metal center interactions to occur by the coordination of the nitrogen atom of the amino group and the oxygen atom of the carboxylic acid of the structure of furosemide. With the results of the levels of metal, elemental analysis (CHN) and thermal analysis has been possible to propose the structure of the ligand. The values of the molar conductivity of the complex in acetonitrile behavior suggest the non acetonitrile electrolyte solution. With the solubility tests it was found that the compounds have high solubility in methanol and acetonitrile, as are partially insoluble in water. From the results of thermal analysis (TG, DSC, DTA), it was possible to obtain the thermal behavior of the compounds as stages of dehydration, thermal stability, decomposition and the energies involved.

Síntese e caracterização do líquido iônico tetrafluoroborato de 1-metil-3-(2,6-(S)-dimetiloct-2-eno)-imidazol como eletrólito para produção de hidrogênio via eletrólise da água

Ionic liquids (ILs) are organic compounds liquid at room temperature, good electrical conductors, with the potential to form as a means for electrolyte on electrolysis of water, in which the electrodes would not be subjected to such extreme conditions demanding chemistry [1]. This paper describes the synthesis, characterization and study of the feasibility of ionic liquid ionic liquid 1-methyl-3(2,6-(S)-dimethyloct-2-ene)-imidazole tetrafluoroborate (MDI-BF4) as electrolyte to produce hydrogen through electrolysis of water. The MDI-BF4 synthesized was characterized by thermal methods of analysis (Thermogravimetric Analysis - TG and Differential Scanning Calorimetry - DSC), mid-infrared spectroscopy with Fourier transform by method of attenuated total reflectance (FTIR-ATR), nuclear magnetic resonance spectroscopy of hydrogen (NMR 1H) and cyclic voltammetry (CV). Where thermal methods were used to calculate the yield of the synthesis of MDI-BF4 which was 88.84%, characterized infrared spectroscopy functional groups of the compound and the binding B-F 1053 cm-1; the NMR 1H analyzed and compared with literature data defines the structure of MDI-BF4 and the current density achieved by MDI-BF4 in the voltammogram shows that the LI can conduct electrical current indicating that the MDI-BF4 is a good electrolyte, and that their behavior does not change with the increasing concentration of water

Co-circulação dos vírus dengue tipo 1, 2 e 4 nos Estados do Rio Grande do Norte e Paraíba, 2013

Dengue is a viral disease transmitted by female mosquitoes from genus Aedes, the principal urban vector is Aedes aegypti. Actually dengue has caused, in global scale, substantial morbidity and mortality. Four serotypes (antigenically distinct) are known: DENV-1, DENV-2, DENV-3 and DENV-4. The objective of this study was described the epidemiological profile dengue in the states of Rio Grande do Norte (RN) and Paraíba (PB), 2013. For that, suspected cases of dengue were studied, received for Laboratory of Molecular Biology of infectious disease and cancer (LADIC-UFRN) from different Health Units from RN and PB between January and December of 2013. The viral RNA was obtained from serum samples of patient from health units from RN and PB. It were studied 478 suspected cases of dengue , 252 (52,7%) from Rio Grande do Norte and 226 (47,3%) from Paraíba, showeds a global rate of infection global prevalence of 29,7% (142/478). The co-circulation of three serotypes was observed: DENV-1 (9,8% [14/142]), DENV-2 (3,5% [5/142]) and DENV-4 (86,7% [123/142]). People between 21-30 years old were the most affected by the disease during all the period of the study, representing 63,7% of the cases in both states. The genus most affected was female, representing 63,3% of cases in both states. Pau dos Ferros, Rio Grande do Norte, had the highest circulation of disease, with 8,2% (8/97) of cases. In Paraíba, the city most affected was João Pessoa, with (80% (36/45) of cases. The months with the biggest viral circulation in RN and PB were March and August, respectively. These results are very important to understanding the dengue viral activity in RN and PB, providing data that can guide control actions of this disease in support to local control programs

Effect of acetyl resin retentive arms on the retentive force ofcircumferential clasps: an in vitro study.

PURPOSE: To compare and to evaluate the stability of the retentive force of cobalt-chromium (Co-Cr) circumferential clasps (control) to those with an acetyl resin retentive arm. METHODS: Sixteen specimens with a couple of circumferential clasps were made using Co-Cr over a metal model providing 0.25 mm undercuts. Eight specimens were fabricated without the anterior retentive arm, which was made later using acetyl resin (Dental D). Insertion and removal simulation test was performed through 7250 cycles. The retentive force was recorded in Newtons (N) for periods corresponding to 0, 1, 2, 3, 4, and 5 years. The data were subjected to ANOVA and Tukey test to compare periods and to Student's t test to compare groups (α=0.05). RESULTS: Mean (SD) is presented for Co-Cr and resin groups, respectively: 8.09(3.05) and 2.79(1.57) in period 0; 10.48(4.25) and 3.32(1.92) in 1 year; 10.09(4.15) and 3.47(1.81) in 2 years; 9.87(4.30) and 3.46(1.87) in 3 years; 9.46(3.93) and 3.27(1.59) in 4 years; 9.63(3.79) and 3.41(1.59) in 5 years. There were significant differences for Co-Cr between periods of 0 and 1 (p<0.001), 0 and 2 (p<0.01) and 0 and 3 (p<0.05). In the resin group, no significant differences were found between periods (p>0.05). Comparisons between the groups showed statistical differences for all tested periods: 0 (p=0.0012), 1 (p=0.0013), 2 (p=0.0019), 3 (p=0.0031), 4 (p=0.0027) and 5 years (p=0.0014). CONCLUSIONS: Acetyl resin retentive arms, even if only in the anterior clasps, can significantly reduce the retentive force, but this force remained stable after 5 years of simulated use.