Uso de metamaterial em antenas de microfita com supercondutor

Metamaterials have attracted great attention in recent decades, due to their electromagnetic properties which are not found in nature. Since metamaterials are now synthesized by the insertion of artificially manufactured inclusions in a specified homogeneous medium, it became possible for the researcher to work with a wide collection of independent parameters, for example, the electromagnetic properties of the material. An investigation of the properties of ring resonators was performed as well as those of metamaterials. A study of the major theories that clearly explain superconductivity was presented. The BCS theory, London Equations and the Two-Fluid Model are theories that support the application of superconducting microstrip antennas. Therefore, this thesis presents theoretical, numerical and experimental-computational analysis using full-wave formalism, through the application of the Transverse Transmission Line – LTT method applied in the Fourier Transform Domain (FTD). The LTT is a full wave method, which, as a rule, obtains the electromagnetic fields in terms of the transverse components of the structure. The inclusion of the superconducting patch is performed using the complex resistive boundary condition. Results of resonant frequency as a function of antenna parameters are obtained. To validate the analysis, computer programs were developed using Fortran, simulations were created using the commercial software, with curves being drawn using commercial software and MATLAB, in addition to comparing the conventional patch with the superconductor as well as comparing a metamaterial substrate with a conventional one, joining the substrate with the patch, observing what improves on both cas

Desenvolvimento e caracterização de nanoemulsões cosméticas contendo extrato de Opuntia ficus-indica L. Mill e avaliação in vivo da eficácia hidratante

Nanoemulsions are emulsified systems, characterized for reduced droplet size (50- 500nm), which the main characteristic are kinect stability and thermodynamic instability. These are promising systems on cosmetic area due to their droplet size that provide different advantages when compared to conventional systems, among others, larger surface area and better permeability. The Opuntia ficus-indica (L.) Mill is a plant cultivated on Caatinga Brazilian biome, which has great socioeconomic importance to region. This plant shows carbohydrates utilized for cosmetic industry as moisturizing active in their chemical composition. The aim of study was to develop, characterize, evaluate stability and moisturizing efficacy of cosmetic nanoemulsions added to Opuntia ficus-indica (L.) Mill extract. Nanoemulsions preparation was made using a low energy method. Different nanoemulsions were formulated varying the ratio of oil, water and surfactant phases beyond xanthan gum (0.5% e 1%) and Opuntia ficus-indica (L.) Mill hydroglycolic extract addition on 1% and 3%. Obtained nanoemulsions were submitted to preliminary and accelerated stability tests. The evaluated parameters monitored were: macroscopic aspect, pH value, droplet size, zeta potential and polydispersion index, during 60 days on different temperatures. Stable formulations were submitted to moisturizing efficacy assessment by capacitance and transepidermal water loss methodologies during 5 hours. Stable samples were white and showed homogeneous and fluid aspect, pH value was inside ideal range (4,5-6,0) to topical application and droplet size under 200nm characterizing these system as nanoemulsions. Developed nanoemulsions did not decrease transepidermal water loss, however increased the water content on stratum corneum, highlighting the nanoemulsions containing 0.5% of xanthan gum and 1% of hydroglycolic extract. This work presents cosmetic moisturizing nanoemulsions composed to vegetal raw material from Brazilian Caatinga with potential to be used on cosmetic area.

Estudo experimental sobre o comportamento do escoamento bifásico água - ar para a medição de vazão em placa de orifício

The measurement of flow through the prediction of differential pressure is widely used in industrial day-to-day, this happens mainly due to the fact that it is used for various types of fluids, such as gas flow and liquid with viscosity distinct even flow of fluids with particles in suspension. The suitability of this equipment for measuring mass flow in two-phase flow is of paramount importance for technological development and reliability of results. When it comes to two-phase flow the relationship between the fluids and their interactions are of paramount importance in predicting the flow. In this paper, we propose the use of concentric orifice plate used in small diameter pipes of 25.4 mm order where a two-phase flow flows between water-air. The measurement of single-phase flow was made with the use of data in NBR 5167-1 which was used to Stolz equation for measuring discharge coefficient. In the two-phase flow was used two correlations widely used in the prognosis of mass flow, the pattern of Zhang (1992) and the model of Chisholm (1967), to the homogeneous flow model. It was observed that the behavior found in Zhang model are consistent more realistic way the mass flow of two-phase flow, since the model Chisholm extrapolate the parameters for the downstream pressure P2, the orifice plate, and the rated discharge coefficient. The use of the change in pressure drop P1-P2 and discharge coefficient, led to a better convergence of the values obtained for the two-phase air-water stream.

Usos de membranas de quitosana na remoção de cobre em águas residuais

In this work a chitosan (CS) ionically crosslinked were manufactured by treatment with sulfuric acid solution for application in the treatment of wastewater from oil industry. Two crosslinking process were developed: homogeneous and heterogeneous. In the homogeneous process the ratio molar of SO42-/ NH3+ (1:6 and 1:4) were the variable analyzed, denominated CS16 and CS14 respectively. In the heterogeneous process the soaking time of the membranes in sulfuric acid solution were the variable studied, being used times of 5 (CS5) and 30 (CS30) minutes. FTIR-ATR results indicated no changes in the characteristics of chitosan after homogeneous crosslinking process, while heterogeneous crosslinking showed formation of ionic bonds between protonated groups from chitosan and the crosslinking agent sulfate ions. TG/DTG and XRD analysis confirmed the formation of these interactions, as also shown the new structure on the surface region of CS5 and CS30 membranes compared to CS, CS16 e CS14. Swelling test in aqueous medium have shown that crosslinking process reduced the membrane sorption capacity. Swelling test in acid medium demonstrated that CS16 and CS14 membranes increasing the adsorption capacity up to a maximum percentage of 140% approximately, whereas the CS5 e CS30 reached a maximum of 60%. The mechanical properties indicated the stiff and ductile behavior of crosslinked membrane. Adsorption experiments of CuCl2 results that CS16 membranes reached the efficiency maximum with 73% of copper removal at pH 5.0 and 87% at pH 4.0. The experiments with CuSO4 also obtained efficiency maximum to the CS16 membrane and 80% to the removal of Cu2+ ions. Also was verified that the increase of concentration and temperature cause a decrease in the adsorption capacity for all membranes. Kinetics study indicated that pseudo-second-order obtained characterized better the membranes. Equilibrium studies demonstrated that the CS, CS16 and CS14 follow the Langmuir model, whereas CS5 and CS30 follows Freundlich model. Filtration experiments results with rejection maximum to the CS16 and CS5 membranes, reaching 92 and 98% respectively.

Usos de membranas de quitosana na remoção de cobre em águas residuais

In this work a chitosan (CS) ionically crosslinked were manufactured by treatment with sulfuric acid solution for application in the treatment of wastewater from oil industry. Two crosslinking process were developed: homogeneous and heterogeneous. In the homogeneous process the ratio molar of SO42-/ NH3+ (1:6 and 1:4) were the variable analyzed, denominated CS16 and CS14 respectively. In the heterogeneous process the soaking time of the membranes in sulfuric acid solution were the variable studied, being used times of 5 (CS5) and 30 (CS30) minutes. FTIR-ATR results indicated no changes in the characteristics of chitosan after homogeneous crosslinking process, while heterogeneous crosslinking showed formation of ionic bonds between protonated groups from chitosan and the crosslinking agent sulfate ions. TG/DTG and XRD analysis confirmed the formation of these interactions, as also shown the new structure on the surface region of CS5 and CS30 membranes compared to CS, CS16 e CS14. Swelling test in aqueous medium have shown that crosslinking process reduced the membrane sorption capacity. Swelling test in acid medium demonstrated that CS16 and CS14 membranes increasing the adsorption capacity up to a maximum percentage of 140% approximately, whereas the CS5 e CS30 reached a maximum of 60%. The mechanical properties indicated the stiff and ductile behavior of crosslinked membrane. Adsorption experiments of CuCl2 results that CS16 membranes reached the efficiency maximum with 73% of copper removal at pH 5.0 and 87% at pH 4.0. The experiments with CuSO4 also obtained efficiency maximum to the CS16 membrane and 80% to the removal of Cu2+ ions. Also was verified that the increase of concentration and temperature cause a decrease in the adsorption capacity for all membranes. Kinetics study indicated that pseudo-second-order obtained characterized better the membranes. Equilibrium studies demonstrated that the CS, CS16 and CS14 follow the Langmuir model, whereas CS5 and CS30 follows Freundlich model. Filtration experiments results with rejection maximum to the CS16 and CS5 membranes, reaching 92 and 98% respectively.

A política do argumento de inclusão regional no âmbito da Universidade Federal do Rio Grande do Norte

O acesso ao ensino superior gratuito no Brasil continua sendo um grande desafio para significativa parcela da população. Várias políticas de ações afirmativas têm sido estimuladas no sentido de promover um acesso mais homogêneo às universidades públicas brasileiras. Essa dificuldade no acesso acaba refletindo-se no mercado de trabalho, gerando um desequilíbrio em várias áreas de atuação. Na área de saúde, temos observado que um intenso debate sobre a oferta, a concentração e a fixação de médicos vem acontecendo no Brasil. Embora o número de médicos tenha aumentado nos últimos anos, chama a atenção a desigualdade da distribuição dos mesmos, que prioriza os grandes centros urbanos e as capitais em detrimento dos municípios do interior. A abertura de novos cursos de medicina é uma das estratégias na tentativa de conseguir uma melhor distribuição de médicos nas diversas regiões do Brasil. O presente trabalho teve como objetivo estudar o Argumento de Inclusão Regional da Universidade Federal do Rio Grande do Norte, enquanto política que objetiva priorizar a seleção de estudantes do interior do Estado com vistas a promover maior fixação futura de profissionais nas regiões com maior carência destes, especialmente médicos. Trata-se de estudo exploratório, descritivo, em que a coleta de dados constou de revisão bibliográfica e análise documental. O estudo se desenvolveu em etapas, transformadas em capítulos descritivos que deram forma ao trabalho final. É importante destacar a necessidade de esclarecimento sobre esse instrumento, que pode ser utilizado por todos os novos cursos de Medicina do país como um dos meios para um melhorar o acesso de estudantes das regiões onde os cursos estão inseridos e, com isso, tentar promover, ao final do curso, uma maior fixação de médicos nos municípios do interior do Brasil.

Preparação de catalisadores para reações de esterificação do ácido oleico baseados em matrizes polímericas sulfonadas POLI(1- FENILETILENO) (PS) e POLI(1-CLOROETILENO) (PVC)

Chemical modification of polymer matrices is an alternative way to change its surface properties. The introduction of sulfonic acid groups in polymer matrices alter properties such as adhesion, wettability, biocampatibility, catalytic activity, among others. This paper describes the preparation of polymeric solid acid based on the chemical modification of poly (1-fenietileno) (PS) and Poly (1-chloroethylene) (PVC) by the introduction of sulfonic acid groups and the application of these polymers as catalysts in the esterification reaction of oleic acid with methanol. The modified materials were characterized by Infrared Spectroscopy, Elemental Analysis and titration acid-base of the acid groups. All techniques confirmed the chemical changes and the presence of sulfur associated with sulfonic acid groups or sulfates. The modified polymers excellent performance in the esterification reaction of oleic acid with methanol a degree of conversion higher than 90% for all investigated polymers (modified PS and PVC (5% w / w)), with a mass ratio of oleic acid: methanol 1:10 to 100 ° C. The best performance was observed for the modified PVC catalyst (PVCS) which showed low degree of swelling during the reactions is recovered by filtration different from that observed for polystyrene sulfonate (PSS). Given these facts, the PVCS was employed as a catalyst in the esterification reaction of oleic acid in different times and different temperatures to obtain the kinetic parameters of the reaction. Experimental data show a great fit for pseudo-homogeneous model of second order and activation energy value of 41.12 kJ mol -1, below that found in the literature for the uncatalyzed reaction, 68.65 kJ mol -1 .The PVCS exhibits good catalytic activity for 3 times of reuse, with a slight decrease in the third cycle, but with a conversion of about 78%. The results show that solid polymeric acid has good chemical stability for the application in esterification reaction of commercial importance with possible application in the biodiesel production. The advantages in use of this system are the increased reaction rate at about 150 times, at these test conditions, the replacement of sulfuric acid as a catalyst for this being the most corrosive and the possibility of reuse of the polymer for several cycles.

Relaciones entre mareas y otros fenómenos geodinámicos: estudios en la Península Ibérica y California

En el ámbito de la investigación sobre Mareas, existen controversias que han dado lugar a extensos debates científicos y a la publicación de resultados contradictorios. Dos de estas discusiones, ampliamente conocidas, son la interpretación geofísica de los residuos finales de marea gravimétrica y la existencia o no de correlación entre las mareas y la ocurrencia de terremotos. El objetivo fundamental de esta tesis doctoral es realizar aportaciones a ambos aspectos de forma significativa y relevante. Si a las amplitudes y desfasajes de las componentes armónicas del potencial de mareas obtenidas a partir de datos de observación les restamos la parte correspondiente al modelo teórico de marea sólida y también la parte correspondiente al efecto oceánico, obtenemos un vector residuo final de marea cuya interpretación es un asunto muy debatido en Geodesia. Mientras que algunos autores sugieren que los residuos finales están relacionados con posibles errores instrumentales y de medida o con errores en la evaluación de los cálculos de la carga oceánica, otros proponen ciertas relaciones empíricas entre estos residuos finales de marea gravimétrica y parámetros que implican variaciones estructurales con respecto a un modelo de Tierra elástico homogéneo, como el flujo térmico o la edad tectonotérmica de la litosfera...

El filme de vanguardia mudo y los nuevos medios digitales del siglo XXI: autores principales, estructuras plásticas complejas y estrategias creativas

El origen y naturaleza de la investigación refieren al filme de vanguardia mudo como forma plástica y recurso técnico adjunto a los nuevos medios mecánicos de principios del siglo veinte – léase, fotografía, fotomontaje, cine, impresión offset - y sus correspondencias creativas y metodológicas con la vanguardia del software informático y nuevos medios digitales. En este sentido, la propuesta conceptual y formal señala este campo de correspondencias y combinatorias como plataforma de análisis crítico y proyectual, antes que un sistema homogéneo de interpretación y sistematización del ámbito de interés. El filme de vanguardia deriva de las mediaciones sociales, científicas y políticas de las vanguardias artísticas en arte, diseño y arquitectura de las primeras décadas de la era industrial. A este respecto, los filmes seleccionados se realizaron durante el período mudo; es decir, no hay diálogos ni banda sonora incorporada al material fílmico. Sin embargo, en estricto rigor, tampoco es correcto identificarlos a tábula rasa con la denominada estética muda; puesto que esta obra refiere otra interfaz, otro vector y botón de búsqueda de los pioneros de la nueva visión mecánica...

La Derecha Conservadora en los Debates Parlamentarios (1930-1943)

El 6 de septiembre de 1930 una revolución, encabezada por el General Uriburu, destituyó de la presidencia a Hipólito Irigoyen, produciéndose el primer quiebre institucional en la vida política argentina. Dicho golpe de Estado, no sólo mostró la incapacidad del sistema democrático de canalizar el conflicto en su interior, sin recurrir a métodos extraordinarios, sino que contribuyó posteriormente al restablecimiento del fraude en el sistema electoral y dio paso a un proceso de inestabilidad democrática que se proyectó en períodos subsiguientes. Esta situación se desarrollaba dentro de un contexto mundial, en el que se producía el ascenso y consolidación de gobiernos totalitarios en Europa, frente a democracias liberales que atravesaban una profunda crisis tanto económica como política. El propósito de este trabajo es analizar las posiciones adoptadas por los miembros de la Concordancia (socialistas independientes, radicales antipersonalistas y demócratas 1nacionales) a partir del estudio de la evolución de las temáticas planteadas en la escena parlamentaria. Se parte de la hipótesis de que dicho bloque dominante durante la década del 30, no constituyó un bloque homogéneo y que las disidencias entre ellos y otros sectores generó no sólo el debilitamiento y dispersión de sus fuerzas sino un nuevo reacomodamiento político a partir de 1943. El análisis de las posturas de los sectores que constituían la Concordancia en los debates parlamentarios aportará nuevos elementos para establecer el posicionamiento de esas diferentes fuerzas, teniendo en cuenta que en gran parte de la literatura sobre el tema se ha tendido a diluir su heterogeneidad

La Derecha Conservadora en los Debates Parlamentarios (1930-1943)

El 6 de septiembre de 1930 una revolución, encabezada por el General Uriburu, destituyó de la presidencia a Hipólito Irigoyen, produciéndose el primer quiebre institucional en la vida política argentina. Dicho golpe de Estado, no sólo mostró la incapacidad del sistema democrático de canalizar el conflicto en su interior, sin recurrir a métodos extraordinarios, sino que contribuyó posteriormente al restablecimiento del fraude en el sistema electoral y dio paso a un proceso de inestabilidad democrática que se proyectó en períodos subsiguientes. Esta situación se desarrollaba dentro de un contexto mundial, en el que se producía el ascenso y consolidación de gobiernos totalitarios en Europa, frente a democracias liberales que atravesaban una profunda crisis tanto económica como política. El propósito de este trabajo es analizar las posiciones adoptadas por los miembros de la Concordancia (socialistas independientes, radicales antipersonalistas y demócratas 1nacionales) a partir del estudio de la evolución de las temáticas planteadas en la escena parlamentaria. Se parte de la hipótesis de que dicho bloque dominante durante la década del 30, no constituyó un bloque homogéneo y que las disidencias entre ellos y otros sectores generó no sólo el debilitamiento y dispersión de sus fuerzas sino un nuevo reacomodamiento político a partir de 1943. El análisis de las posturas de los sectores que constituían la Concordancia en los debates parlamentarios aportará nuevos elementos para establecer el posicionamiento de esas diferentes fuerzas, teniendo en cuenta que en gran parte de la literatura sobre el tema se ha tendido a diluir su heterogeneidad

La Derecha Conservadora en los Debates Parlamentarios (1930-1943)

El 6 de septiembre de 1930 una revolución, encabezada por el General Uriburu, destituyó de la presidencia a Hipólito Irigoyen, produciéndose el primer quiebre institucional en la vida política argentina. Dicho golpe de Estado, no sólo mostró la incapacidad del sistema democrático de canalizar el conflicto en su interior, sin recurrir a métodos extraordinarios, sino que contribuyó posteriormente al restablecimiento del fraude en el sistema electoral y dio paso a un proceso de inestabilidad democrática que se proyectó en períodos subsiguientes. Esta situación se desarrollaba dentro de un contexto mundial, en el que se producía el ascenso y consolidación de gobiernos totalitarios en Europa, frente a democracias liberales que atravesaban una profunda crisis tanto económica como política. El propósito de este trabajo es analizar las posiciones adoptadas por los miembros de la Concordancia (socialistas independientes, radicales antipersonalistas y demócratas 1nacionales) a partir del estudio de la evolución de las temáticas planteadas en la escena parlamentaria. Se parte de la hipótesis de que dicho bloque dominante durante la década del 30, no constituyó un bloque homogéneo y que las disidencias entre ellos y otros sectores generó no sólo el debilitamiento y dispersión de sus fuerzas sino un nuevo reacomodamiento político a partir de 1943. El análisis de las posturas de los sectores que constituían la Concordancia en los debates parlamentarios aportará nuevos elementos para establecer el posicionamiento de esas diferentes fuerzas, teniendo en cuenta que en gran parte de la literatura sobre el tema se ha tendido a diluir su heterogeneidad

What do school principals do? Leadership practices in Spain drawn from PISA and TALIS international studies

Principals play a key role in schools. Their actions affect the efficacy of schools and indirectly on the students’ academic performance. Numerous studies describe the different activities that principals perform in their daily practice, grouping them in dimensions, not existing unanimity neither around the practices carried out nor the dimensions. In Spain, the new educational law, LOMCE, emphasizes the importance of looking into what international research says regarding the field of education to support the need for change and justify the ones that are being made, and develops an extended list of competences of the principal. This study is a synthesis of a narrative research with the following analysis unit: the results of the PISA (Programme for International Student Assessment) and TALIS (Teaching and Learning International Study) international reports, and the data provided on school leadership and their practices, from which conclusions are inferred, comparing them with the competences stated in the LOMCE. The comparative analysis of the leadership practices presented depicts a still uneven and heterogeneous scenario, not existing agreement neither for the setting of boundaries for the leadership dimensions, nor for the number of practices that constitute them. Such a scenario points towards the need for further empirical research, in order to accurately obtain a homogeneous catalogue of the actions carried out by principal, that may open the door to the development of the role of principal, and to the improvement of effectiveness and performance of schools, as it is suggested internationally, and it is an objective of the new educational law.

La lengua como canon y como objeto de crítica en la gramática normativa

La selección de las muestras de ejemplos que se emplean en la codificación normativa del español está relacionada con las concepciones teóricas que en cada época histórica sirven de base para acometer la reflexión gramatical. La autoridad sobre el uso ha correspondido tradicionalmente en la preceptiva académica a las fuentes literarias, que se han empleado fundamentalmente para ilustrar la pauta normativa tanto en la labor lexicográfica como en la gramatical. La incorporación de nuevas tipologías textuales en la producción académica está vinculada a un cambio en la concepción teórica en la que una lengua ya no es concebida como un bloque monolítico y homogéneo, sino donde la variación lingüística se constituye en rasgo inherente a su misma condición histórica. De ahí que no resulte extraño que en la nómina de textos sea cada vez más frecuente encontrar un amplio corpus conformado por publicaciones periódicas. Esta incorporación de muestras periodísticas en la reciente producción académica, materializada en el Diccionario panhispánico de dudas (2005) y en la Nueva gramática de la lengua española (2009), viene a suplir en cierta medida también el silencio normativo académico ante las dudas y vacilaciones lingüísticas planteadas por los profesionales de los medios de comunicación. Tras el rastreo histórico de la aparición de muestras periodísticas en la ejemplificación normativa académica, se tratará de establecer si se ha producido un cambio en la funcionalidad de estas citas de manera que no sean ya empleadas exclusivamente con la valoración de ejemplaridad idiomática, tal y como se utilizaban fundamentalmente las muestras extraídas de los textos literarios en la labor de codificación tradicional de la Academia, sino también como variantes incorrectas objeto de una crítica más o menos velada hacia determinados usos circunscritos mayoritariamente al discurso periodístico actual.

The Challenge of Migration and the Global Security Strategy of the European Union

This article discusses the challenges of irregular migration for the security of the EU. They are analyzed starting with the European Security Strategy 2003, and the Report on its Implementation, 2008, and notes many failures: The EU Members did not follow the directives adopted in Brussels, the mismanagement of migration and asylum policies, and numerous actions that can be characterized or described as improvised, scattered or irresponsible. The 2016 Global Strategy recognizes these failures and call attention to the European leaders to reconsider how the EU functions and operates, suggesting the need for greater unity and cooperation to achieve a more effective migration policy. However, the article points out that practically all of the sections of the new Strategy dealing with migration were already embodied in previous Strategies, and stress that in parallel with the publication of the 2016 Global Strategy, actions are already undertaken, such as the EU readmission agreements signed with several important third countries of origin.