Efeito Peltier em estruturas semicondutoras quasiperiódicas

There is nowadays a growing demand for located cooling and stabilization in optical and electronic devices, haul of portable systems of cooling that they allow a larger independence in several activities. The modules of thermoelectrical cooling are bombs of heat that use efect Peltier, that consists of the production of a temperature gradient when an electric current is applied to a thermoelectrical pair formed by two diferent drivers. That efect is part of a class of thermoelectrical efcts that it is typical of junctions among electric drivers. The modules are manufactured with semiconductors. The used is the bismuth telluride Bi2Te3, arranged in a periodic sequence. In this sense the idea appeared of doing an analysis of a system that obeys the sequence of Fibonacci. The sequence of Fibonacci has connections with the golden proportion, could be found in the reproductive study of the bees, in the behavior of the light and of the atoms, as well as in the growth of plants and in the study of galaxies, among many other applications. An apparatus unidimensional was set up with the objective of investigating the thermal behavior of a module that obeys it a rule of growth of the type Fibonacci. The results demonstrate that the modules that possess periodic arrangement are more eficient

Histological evaluation of the lesion induced by inoculation of Leishmania mexicana in the cheek pouch of the hamster

No presente estudo, investigamos o papel da resposta imune na morfologia do granuloma leishmaniótico induzido na bolsa jugal do hamster, um local imunologicamente privilegiado, após inoculação de 3x10(5) Leishmania mexicana. Os animais foram avaliados histológica e imunologicamente até os 120 dias da inoculação. Independente da época do sacrifício, os animais foram sempre não reatores ao teste do coxim plantar. Histologicamente, a inoculação de Leishmania mexicana na bolsa jugal resultou na formação de abcesso que evoluiu para reação granulomatosa rica em formas amastigotas e, posteriormente, para resolução. Esses resultados sugerem que o desenvolvimento da resposta imune não é preponderante no controle da infecção induzida pela Leishmania mexicana inoculada subcutaneamente na bolsa jugal do hamster. Sugerem ainda que os macrófagos que compõe os granulomas leishmanióticos são capazes de eliminar esse parasita, independente da presença de resposta imune avaliável pelo teste do coxim plantar.

Contribuição ao estudo da reação á tricofitina nas dermatofitoses

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Criar o próprio jogo didático ou apenas jogar? Efeitos de diferentes estratégias de ensino na motivação e aprendizado de ciências

The use of games as educational tools is common, however the effectiveness of games with educational purposes is still poorly known. In this study we evaluated three different low-cost teaching strategies make and play your own board game, just play an educational science game and make a poster to be exposed in the school regarding: (1) science learning; (2) use of deep learning strategies (DLS); and (3) intrinsic motivation. We tested the hypothesis that, in these three parameters evaluated, scores would be higher in the group that made and play their own game, followed respectively by the group that just played a game and the group that made a poster. The research involved 214 fifth-grade students from six elementary schools in Natal/RN. A group of students made and played their own science board game (N = 68), a second group played a science game (N = 75), and a third group made a poster to be exposed at school (N = 71). Our hypothesis was partly empirically supported, since there was no significant difference in science learning and in the use of DLS between the group that made their own game and the group that just played the game; however, both groups had significantly higher scores in science learning and in use of DLS than the group that made the poster. There was no significant difference in the scores of intrinsic motivation among the three experimental groups. Our results indicate that activities related to non-digital games can provide a favorable context for learning in the school environment. We conclude that the use of games for educational purposes (both making a game and just playing a game) is an efficient and viable alternative to teach science in Brazilian public school

Compromisso social do psicólogo em artigos publicados em periódicos científicos no Brasil

Psychologist s social commitment in scientific articles published in scientific papers in Brazil. A situation analysis of the scientific production concerning psychologist s social commitment can aid the historical constitution of this theme and also subsidize reflections about the course of this profession in Brazil. In order to contribute to this debate, the theme social commitment of psychologist was analyzed in the scientific literature concerning psychologist profession in the country. Specifically, papers about the profession that mentioned the theme social commitment were characterized and their approach of this matter was analyzed. In order to accomplish these goals, two research stages were fulfilled: first, in a systematic search for scientific literature in internet databases, studies about the psychologist profession in the country were gathered; in the second stage, scientific papers relating to social commitment in their titles, abstracts or keywords were selected. 61 papers were retrieved, organized in electronic database and full-text analyzed, based in two axis: scientometric and thematic. The papers were identified, in general, as recent, of theoretic character and aligned with several Psychology subareas; mainly produced in public universities, in country s southwest; were of conjunctural interest to the authors research projects, individually published, by professors in touch with post-graduation; published in open access journals, with high Qualis evaluation. It was verified that there is no consensus on the meaning of the theme, prevailing definitions concerning the understanding of the social reality, to the majority of people or to a progressive-aligned professional performance. Are adduced as committed agents: the psychologist (sometimes together with other kinds of professionals or with users), the academia, and the representative entities of the profession. Depending on the subareas and the nature of study, all papers mentioned at least one of the following criteria: expansion of target-audience, renewal of practices, political direction, defined theoretical approach or adequate technical competence, sometimes relating each other. In short, psychologist s social commitment is a contradictory issue which have earned projection in scientific literature, reiterating the historical custom of evaluate the psychologist profession. As conclusion, it is regarded as indispensable to intensify the reflection about the role whose psychologist plays in a class-cleaved society and the limits and potentials of his performing in that framework.

Contribuições do Programa Institucional de Bolsas de Iniciação Científica (PIBIC) para a formação do aluno de psicologia

The undergraduate courses in Psychology have been historically pointed as defective in aspects related to the critical education and the integration between theory and practice. Hence, the scientific education has been considered a possibility to overcome those lacks. Therefore, this study has investigated the undergraduate education process of Psychology students with PIBIC (Portuguese acronym for Undergraduate Scientific Research Scholarships Institutional Program) scholarships from CNPq (Portuguese acronym Brazilian National Council of Scientific and Technological Development). The scholarship program has been a strategic tool for the undergraduate scientific research. Electronic questionnaires have been sent to all the PIBIC scholarship students of Psychology in Brazil (622; 104 have answered), containing questions about the program developed activities, tutoring and advising, PIBIC evaluation and other ones. The students scientific and academic production has also been investigated through their Lattes (CNPq s Platform in which researchers have their academic résumés). The major part of the participants (70%) has stated that the first motivation to be in the program had been their interest in the research or in the academic career. Furthermore, 60% of the scholarship students has worked as volunteers before receiving PIBIC scholarship. Among the students who have answered the research, 65,4% has reported they are tutored directly by their advisors, and 80% of them attends one or more than one advising meeting every fifteen days. It has been identified that the Psychology scholarship students do not participate in all the research activities and that the proximity with the advisor is related to the accomplishment of tasks which contributes with the student critical and reflexive education. Finally, less than 25% of the students has published scientific articles or book chapters during the scholarship, what XI demonstrates a possible exclusion of them in that phase of the process. In general, the scholarship students evaluate the program positively by revealing that it contributes with their professional and academic education. For those reasons, it is observed PIBIC s potential role for the undergraduate education in order to develop more critical psychologists able to propose innovations and contextualized practices. However, the results obtained in programs like the studied one denounce the disqualification of the provided undergraduate education for the major part of the university students, who do not have a PIBIC scholarship. As a result, it is emphasized that it there should be more investment for improving the quality of the undergraduate education itself and not only for programs which are available for few students

Preparação de resinas de poliuretana à base de óleo de mamona e dietanolamina

The aim of this work was the preparation of polyols from reactions between castor oil and dietanolamine to increase the hydroxyl content and the network degree in the products to application in electronic devices. The polyols and the mixtures obtained were characterized by nuclear magnetic ressonance. Castor oil (CO) is a natural triglyceride - based polyol possessing hydroxyl groups, which allow several reactions that produce many different products. Among them are the polyurethanes (PU), which have been considered an ideal product for the covering of electricelectronic circuits, due to their excellent electrical, shock-absorbing, solvents resistance and hydrolytic stability properties. About 90% of the fatty acids present in the castor oil are ricinoleic acid (12-hydroxyoleic acid), while the remaining 10% correspond to non-hydroxylated fatty acids, mainly linoleic and oleic acids. The chemical analysis of castor oil indicates a hydroxyl number of 2.7. In this work, a polyol was obtained by the reaction of the CO with diethanolamine (DEA), in order to elevate the hydroxyl value from 160 to 230 or to 280 mgKOH/g, and characterized by nuclear magnetic resonance (NMR) 1H and 13C (Mercury 200). The polyadition of the resulting polyol with isophorone diisocianate (IPDI) was carried out at 60°C, and the reaction kinetics was followed by rheological measurements in a Haake RS150 rheometer. The electrical properties were determined in a HP LCR Meter 4262A, at 1.0 Hz and 10.0 KHz. The chemical analysis showed that the polyols obtained presented hydroxyl number from 230 to 280 mgKOH/g. The polyadition reaction with IPDI produced polyurethane resins with the following properties: hardness in the range from 45 shore A to 65 shore D (ASTM D2240); a dielectric constant of 3.0, at 25°C (ASTM D150). Those results indicate that the obtained resins present compatible properties to the similar products of fossil origin, which are used nowadays for covering electric-electronic circuits. Therefore, the PUs from castor oil can be considered as alternative materials of renewable source, free from the highly harmful petroleum - derived solvents

Avaliação da remoção de hidrocarbonetos aromáticos (BTEX) em águas utilizando materiais nanoestruturados do tipo Ti-MCM-41

Volatile Organic Compounds are pollutants coming mainly from activities that use fossil fuels. Within this class are the BTEX (benzene, toluene, ethylbenzene and xylenes) compounds that are considered hazardous. Among the various existing techniques for degradation of pollutants, there is advanced oxidation using H2O2 generating hidoxil radical ( OH). In this work, the mesoporous material of MCM-41 was synthesized by hydrothermal method and then was used as support, the impregnation of titanium by the method of synthesis with excess solvent to obtain the catalyst Ti-MCM-41. The catalyst was used in the reaction catalyzed removal of BTEX in water using H2O2 as oxidant. The materials were characterized by: XRD, TG/DTG, FTIR, nitrogen adsorption-desorption and FRX-EDX, in order to verify the method of impregnation of the mesoporous titanium support was effective. Catalytic tests were carried out in reactors of 20 mL containing BTEX (100.0 μg/L), H2O2 (2.0 M) and Ti-MCM-41 (2.0 g/L) in acid medium. The reaction occurred for 5 h at 60 °C and analysis were performed by gas chromatography with photoionization detector and static headspace sampler. The characterizations have proven the effectiveness of the synthesis method used and the incorporation of titanium lt in the support. The catalytic tests showed satisfactory results with conversion of more than 95 % for the studied compounds, where the catalyst 48% Ti-MCM-41 showed a higher removal efficiency of the compounds under study

Obtenção e Caracterização Físico-Química do Sistema Compósito PEG-TiO2

Hybrid systems formed from polymers and transition metals have now their physical and chemical properties extensively investigated for use in electronic devices. In this work, Titanium Dioxide (TiO2) from the precursor of titanium tetrabutoxide and the composite system Poly(Ethylene Glycol)-Titanium Dioxide (TiO2-PEG) were synthesized by sol-gel method. The PEG as acquired and TiO2 and composites powders were analyzed by X-Ray Diffraction (XRD), Spectroscopy in the Infrared region with Fourier transform (IRFT), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) and Electrochemical Impedance Spectroscopy (EIS). In the XRD analysis were observed in the TiO2 crystal faces of one of its polymorphs - anatase phase, crystal planes in Poly (Ethylene Glycol) with considerable intensity and in the composite systems the mixture of crystal faces of their precursors isolated and reduction of crystallinity. The TG / DTG suggested increasing the thermal instability of PEG in the composite powders as TiO2 is incorporated into the system. Spectral analysis presented in the infrared overlapping bands for the polymer and metal oxide, reducing the intensity of symmetric stretching of ligand groups in the main chain polymer and angular deformations; were observed using SEM micrographs of the morphological changes suffered by composite systems with the variation of the oxide concentration. Analyses by impedance spectroscopy indicated that the increased conductivity in composite occurs in line with the addition of the metal oxide concentration in the composite system

Estudo teórico QTAIM e DFT dos compostos de coordenação: efeito quelato, titanocenos e ligação química

This work is a study of coordination compounds by quantum theory of atoms in molecules (QTAIM), based on the topological analysis of the electron density of molecular systems, both theoretically and experimentally obtained. The coordination chemistry topics which were studied are the chelate effect, bent titanocene and chemical bond in coordination complexes. The chelate effect was investigated according to topological and thermodynamic parameters. The exchange of monodentate ligands on polydentate ligands from same transition metal increases the stability of the complex both from entropy and enthalpy contributions. In some cases, the latter had a higher contribution to the stability of the complex in comparison with entropy. This enthalpic contribution is explained according to topological analysis of the M-ligand bonds where polidentate complex had higher values of electron density of bond critical point, Laplacian of electron density of bond critical point and delocalization index (number of shared electrons between two atoms). In the second chapter, was studied bent titanocenes with bulky cyclopentadienyl derivative π-ligand. The topological study showed the presence of secondary interactions between the atoms of π-ligands or between atoms of π-ligand and -ligand. It was found that, in the case of titanocenes with small difference in point group symmetry and with bulky ligands, there was an nearly linear relationship between stability and delocalization index involving the ring carbon atoms (Cp) and the titanium. However, the titanocene stability is not only related to the interaction between Ti and C atoms of Cp ring, but secondary interactions also play important role on the stability of voluminous titanocenes. The third chapter deals with the chemical bond in coordination compounds by means of QTAIM. The quantum theory of atoms in molecules so far classifies bonds and chemical interactions in two categories: closed shell interaction (ionic bond, hydrogen bond, van der Waals interaction, etc) and shared interaction (covalent bond). Based on topological parameters such as electron density, Laplacian of electron density, delocalization index, among others, was classified the chemical bond in coordination compounds as an intermediate between closed shell and shared interactions

Síntese e caracterização de compostos de coordenação homolépticos e heterolépticos com o ligante ácido kójico

The present work has as main objective to contribute to the coordination chemistry of the ligand kojic acid, with the synthesis and characterization of the homoleptic compounds [Al(kj)3], [Fe(kj)3], [Fe(kj)2], [Cu(kj)2] e [Ru(kj)3], and the new heteroleptic complexes, trans- K2[Fe(kj)2(CN)2] and trans-Na2[Ru(kj)2(CN)2]. The obtained compounds were characterized by vibrational spectroscopy in the infrared region (IV) and Electronic spectroscopy in the ultraviolet and visible region (Uv-Vis). The infrared results indicated the coordination of the bidentate ligand kojic acid, due to reductions in the values of the stretching frequencies of the carbonyl and double bonds, compared to the free ligand for all complexes obtained. The presence of new vibrational modes indicated the change of symmetry of the molecules in the new compounds synthesized. Additionally, the presence of vibrational modes assigned to metal-oxygen also contributed to confirm the ligand coordinating to the metal ions. Through this technique, was also possible to perform correlations of the numbers of vibrational modes, in the region 1400-900 cm-1 and the compounds geometry. The heteroleptic compounds exhibited υC≡N in 2065 and 2053 cm-1, respectively, for the trans-K2[Fe(kj)2(CN)2] and trans-Na2[Ru(kj)2(CN)2], indicating coordination of the cyano ligand to metal ions FeII e RuII. Comparing the obtained values with literature data was possible to identify the complex isomerism as trans. In relation to the results of electronic spectroscopy, studies of pH variation of kojic acid provided information on the distribution of electron density in the molecule, showing characteristic spectral profile of kojic ion and its protonated form (Hkj, kojic acid), with two bands at 215 and 269 nm, or deprotonated (kj-), with bands at 226 and 315 nm. The electronic spectra obtained for all complexes in aqueous medium, in the ultraviolet region, exhibited variations of the energies assigned to kojic acid intraligand transitions while in the visible region, only transitions assigned to charge transfer of iron and ruthenium complex have been identified

Avaliação da remoção catalítica de compostos orgânicos monoaromáticos em água utilizando materiais nanoestruturados de sílica

Statistics of environmental protection agencies show that the soil has been contaminated with problems often resulting from leaks, spills and accidents during exploration, refining, transportation and storage oil operations and its derivatives. These, gasoline noteworthy, verified by releasing, to get in touch with the groundwater, the compounds BTEX (benzene, toluene, ethylbenzene and xylenes), substances which are central nervous system depressants and causing leukemia. Among the processes used in remediation of soil and groundwater contaminated with organic pollutants, we highlight those that use hydrogen peroxide because they are characterized by the rapid generation of chemical species of high oxidation power, especially the hydroxyl radical ( OH), superoxide (O2 -) and peridroxil (HO2 ), among other reactive species that are capable of transforming or decomposing organic chemicals. The pH has a strong effect on the chemistry of hydrogen peroxide because the formation of different radicals directly depends on the pH of the medium. In this work, the materials MCM-41 and Co-MCM-41 were synthesized and used in the reaction of BTEX removal in aqueous media using H2O2. These materials were synthesized by the hydrothermal method and the techniques used to characterize were: XRD, TG/DTG, adsorption/desorption N2, TEM and X-Ray Fluorescence. The catalytic tests were for 5 h of reaction were carried out in reactors of 20 mL, which was accompanied by the decomposition of hydrogen peroxide by molecular absorption spectrophotometry in the UV-Vis, in addition to removal of organic compounds BTEX was performed as gas chromatography with detection photoionization and flame ionization and by static headspace sampler. The characterizations proved that the materials were successfully synthesized. The catalytic tests showed satisfactory results, and the reactions containing BTEX + Co-MCM-41 + H2O2 at pH = 12.0 had the highest percentages of removal for the compounds studied

Revisão por pares na Revista Brasileira de Educação Especial

O artigo discute algumas questões relativas ao procedimento de revisão por pares na avaliação de originais submetidos a um periódico. Essa avaliação é aceita como necessária para assegurar a qualidade científica de artigos publicados, já que a integridade da literatura especializada é considerada essencial para o desenvolvimento da ciência. Entretanto, há críticas à revisão por pares, incluindo o longo tempo decorrido entre a entrega dos originais e a publicação, o tempo e a energia despendidos pelos autores e revisores, a subjetividade na avaliação e outros problemas que podem introduzir vieses na área. A Revista Brasileira de Educação Especial, que adota a avaliação cega por pares, tem-se mostrado relativamente versátil. O tempo médio entre o recebimento dos originais e o aceite final, depois de passar pela revisão por pares e conseqüente ajuste por parte dos autores, é de cerca de cinco meses e meio. Na literatura especializada, encontram-se sugestões como a eliminação de avaliação e publicação de todos os textos submetidos, em meios eletrônicos, menos onerosos e mais versáteis, deixando que os próprios leitores façam a sua avaliação. A análise procedida conclui que a revisão por pares é necessária. Aponta a necessidade de se realizarem discussões sobre a própria avaliação, para que se desenvolvam procedimentos mais eficientes de controle de qualidade das publicações. Sugere que a avaliação efetiva é feita pela própria comunidade acadêmica, após a publicação, mediante reconhecimento coletivo do valor científico da publicação, na forma de impacto que pode causar sobre novas investigações e construção do conhecimento na área.

CrossMDA-SPL: uma abordagem para gerência de variabilidades dirigida por modelos e aspectos

This paper proposes a systematic approach to management of variability modelsdriven and aspects using the mechanisms of approaches Aspect-Oriented Software Development (AOSD) and Model-Driven Development (MDD). The main goal of the approach, named CrossMDA-SPL, is to improve the management(gerência), modularization and isolation ou separation of the variability of the LPSs of architecture in a high level of abstraction (model) at the design and implementing phases of development Software Product Lines (SPLs), exploiting the synergy between AOSD and MDD. The CrossMDA-SPL approach defines some artifacts basis for advance the separation clear in between the mandatory (bounden) and optional features in the architecture of SPL. The artifacts are represented by two models named: (i) core model (base domain) - responsible for specify the common features the all members of the SPL, and (ii) variability model - responsible for represent the variables features of SPL. In addition, the CrossMDA-SPL approach is composed of: (i) guidelines for modeling and representation of variability, (ii) CrossMDA-SPL services and process, and (iii) models of the architecture of SPL or product instance of SPL. The guidelines use the advantages of AOSD and MDD to promote a better modularization of the variable features of the architecture of SPL during the creation of core and variability models of the approach. The services and sub-processes are responsible for combination automatically, through of process of transformation between the core and variability models, and the generation of new models that represent the implementation of the architecture of SPL or a instance model of SPL. Mechanisms for effective modularization of variability for architectures of SPL at model level. The concepts are described and measured with the execution of a case study of an SPL for management systems of transport electronic tickets

Bloqueio contínuo do plexo lombar via posterior bilateral com bomba de infusão descartável: relato de caso

JUSTIFICATIVA E OBJETIVOS: O número de artroplastia total de quadril (ATQ) bilateral tem aumentado a cada ano. Analgesia pós-operatória pela infusão contínua perineural com anestésico local tem se mostrado favorável quando comparada com analgesia sistêmica. O uso de bombas elastoméricas tem aumentado a satisfação do paciente quando em comparação com os modelos eletrônicos. O objetivo deste relato foi descrever um caso de analgesia contínua bilateral do plexo lombar via posterior, com infusão contínua através de bomba elastomérica, em paciente submetido à uma artroplastia bilateral de quadril. RELATO do CASO: Paciente feminina, 46 anos, 65 kg, 162 cm, com artrite reumatoide e hipertensão arterial, estado físico ASA II, escalada para ser submetida a ATQ bilateral em um único estágio. Uso de corticosteroide por 13 anos. Hemoglobina = 10,1 g.dL-1, hematócrito = 32,7%. Monitoração de rotina. Raquianestesia com 15 mg de bupivacaína 0,5% isobárica. Anestesia geral com propofol (PFS) e remifentanil e intubação sem bloqueadores neuromusculares. ATQ direita e no final, bloqueio plexo lombar com estimulador e conjunto agulha 150 mm e injeção de 20 mL bupivacaína 0,2% e passagem de cateter. ATQ esquerda e, no final, mesmo procedimento. Estudado dispersão do anestésico e contraste. Instalado bomba elastomérica com bupivacaína 0,1% (400 mL) em velocidade de 14 mL.h-1. Transferida para Unidade de Cuidados Intensivos (UCI). Vinte e quatro horas após, nova bomba com a mesma solução. Nenhum bolus durante 50 horas. Após remoção de cateter, dor controlada por via oral com cetoprofeno e dipirona. CONCLUSÕES: O bloqueio bilateral contínuo periférico com infusão de bupivacaína a 0,1% com bombas elastoméricas é um procedimento seguro e efetivo em adultos.