Cartas importantes del Papa Clemente XIV (Ganganeli) /

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La conversación consigo mismo /

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Sistema de conversão de energia eólica baseado no gerador de indução duplamente alimentado: análise e contribuição ao controle da máquina

The humanity reached a time of unprecedented technological development. Science has achieved and continues to achieve technologies that allowed increasingly to understand the universe and the laws which govern it, and also try to coexist without destroying the planet we live on. One of the main challenges of the XXI century is to seek and increase new sources of clean energy, renewable and able to sustain our growth and lifestyle. It is the duty of every researcher engage and contribute in this race of energy. In this context, wind power presents itself as one of the great promises for the future of electricity generation . Despite being a bit older than other sources of renewable energy, wind power still presents a wide field for improvement. The development of new techniques for control of the generator along with the development of research laboratories specializing in wind generation are one of the key points to improve the performance, efficiency and reliability of the system. Appropriate control of back-to-back converter scheme allows wind turbines based on the doubly-fed induction generator to operate in the variable-speed mode, whose benefits include maximum power extraction, reactive power injection and mechanical stress reduction. The generator-side converter provides control of active and reactive power injected into the grid, whereas the grid-side converter provides control of the DC link voltage and bi-directional power flow. The conventional control structure uses PI controllers with feed-forward compensation of cross-coupling dq terms. This control technique is sensitive to model uncertainties and the compensation of dynamic dq terms results on a competing control strategy. Therefore, to overcome these problems, it is proposed in this thesis a robust internal model based state-feedback control structure in order to eliminate the cross-coupling terms and thereby improve the generator drive as well as its dynamic behavior during sudden changes in wind speed. It is compared the conventional control approach with the proposed control technique for DFIG wind turbine control under both steady and gust wind conditions. Moreover, it is also proposed in this thesis an wind turbine emulator, which was developed to recreate in laboratory a realistic condition and to submit the generator to several wind speed conditions.

Efeito agudo do exercício aeróbio vigoroso sobre as funções executivas em adolescentes

Executive functions are determinant cognitive processes for student success, since they execute and control complex cognitive activities such as reasoning, planning and solving problems. The development of the executive functions performances begin early at childhood going through the adolescence until adulthood, concomitant with the neuroanatomical, functional and blood perfusion changes over the brain. In this scenario, exercise has been considered an important environmental factor for neurodevelopment, as well as for the promotion of cognitive and brain health. However, there are no large scientific studies investigating the effects of a single vigorous aerobic exercise session on executive functions in adolescents. Objective: To verify the acute effect of vigorous aerobic exercise on executive functions in adolescents. Methods: A randomized controlled trial (RCT) with crossover design was used. 20 pubescent from both sexes/gender with age between 10 and 16 years were submitted to two sessions of 30min each: 1) The aerobic exercise session intensity was between 65 and 75% of heart rate reserve, in which 5min for warm-up, 20min at the target intensity and 5min of cool down; and 2) control session watching cartoons. The computerized Stroop test – Testinpacs and trail making test were used to evaluate the inhibitory control and cognitive flexibility assessment respectively, before and after both experimental and control sessions. The reaction time (RT) and number of errors (n) of Stroop test were recorded. The total time (TT) and the number of errors (n) of the trail making test were also recorded. Results: The control session’s RT did not present significant differences in the Stroop test. On the other hand, the exercise session’s RT decreased significantly (p<0.01) after the session. The number of errors made at the Stroop test had no significant differences in control and exercise sessions. The ΔTT of trail making test of exercise session was significantly (p<0.001) lower than the control session’s. Errors made in trail making test did not show significant differences between control and exercise sessions. Additionally, there was significant and positive association among the Stroop test ΔRT of exercise session with xiii chronological age (r= 0.635, p=0.001; r 2 = 0.404, p=0.003) and sexual maturation (rs= 0.580, p=0.007; r 2 = 0.408, p=0.002). Differently, there was no association among the control session ΔRT and chronological age (r= – 0.144, p=0.273; r 2 = 0.021, p=0.545) or sexual maturation (rs= –0.155, p=0.513; r 2 = 0.015, p=0.610). Conclusion: Vigorous aerobic exercise seems to improve acutely executive functions in adolescents. The effect of exercise on inhibitory control performance was associated to pubertal stage and chronological age. In other words, the benefits of exercise were more evident in early adolescence (↑ ΔRT) and its magnitude decreases along the growing up process.

Projeto de absorvedores de micro-ondas integrados com superfícies seletivas em frequência

Considering the fact that, the use of wireless communication systems has grown too fast, investigations concerning absorbers of electromagnetic waves has called closer attention of researchers. It is applicable from indoor systems to military applications. Paralleling with this growth, some extremely relevant investigations through Frequency Selective Surfaces (FSS) allows its filter property to be applicable in several systems, for example: reflector antennas, band-pass radomes, and absorbers, which are the main objective of this work. Therefore, the main goal of this work concerns to design micro-waves absorbers through FSS. Thus, the methodology consists basically in two steps: the first step concerns a theoretical and numerical analysis of the structures involved in the process of absorption, the second step, the analysis of the cascaded structures. In order to carry out the analysis, the Equivalent Circuit Method will be used. This method provides characteristics of transmission from the structure, for a plane wave incidence and it requires an extremely limited computing resource in relation if compared to full wave analyses method. Hence, it is useful to allow fast predictions of the development of the structures. Furthermore, a spreading matrix will be used in order to cascade the conductive FSS and the resistive FSS achieving absorption characteristics in the designed band. The experimental results used for the analysis are found in the literature due to the difficulty of building soon, given that it is not a simple construction technique. To conclude, a mathematical development through the Equivalent Circuit Method of a FSS modeling with cross-dipole geometry and a resistive FSS will be presented, as well as the cascading involving the two structures. The same setting is used with a square loop geometry. Besides it, the next steps will be discussed in the conclusion.

Efeito agudo da respiração abdominal lenta sobre a atividade cerebral, respostas emocionais e cardiovasculares

Introduction: Slow abdominal breathing (SAB) stimulates baroreflex and generates respiratory sinus arrhythmia, changing cardiovascular, emotional and cerebral systems acute and chronically. However, although meditative practices have been receiving increasingly attention in the last years, there is no agreement on the neurophysiological changes underlying them, mainly because of the lack of topographical pieces of information. Purpose: We aimed to analyze the acute effect of SAB on brain activity, emotional and cardiovascular responses in untrained subjects in meditative techniques. Methods: Seventeen healthy adults’ men were assessed into two different sessions in a random and crossed order. Into experimental session, they breathed in 6 cycles/minute and in control session they kept breathing in normal rate, both for 20 minutes. xi Before, during, and after each session we assessed brain activity using electroencephalography (EEG), anxiety, mood, heart rate variability (HRV) and blood pressure. The sLORETA software was used to analyze EEG data for source localization of brain areas in which activity was changed. Results: The sLORETA showed that beta band frequency was reduced in frontal gyrus (P<0.01) and anterior cingulate cortex (P<0.05) both during and after SAB (P<0.05) compared to the moment before it. There was no change in brain activity in control session. Additionally, a two-way repeated measures ANOVA showed that there was no effect on anxiety (P>0.8) and mood (P>0.08). There were improvements in HRV (P<0.03), with increased RR interval and decreased HR after SAB, as well as increased SDNN, RMSSD, pNN50, low frequency, LF/HF ratio, and total power during it, with no changes in SBP and DBP. Conclusions: We conclude that SAB is able to change brain activity in areas responsible for emotional processing, even without behavioral changes. Furthermore, SAB improves HRV and does not change blood pressure in normotensive.

Efeitos imediatos da plataforma vibratória no desempenho neuromuscular do quadríceps femoral, após reconstrução do LCA: ensaio controlado, randomizado e cego

Objective: to investigate the immediate effect of the vibrating platform on the neuromuscular performance of the quadriceps femoris and on the postural oscillation of subjects submitted to Anterior Cruciate Ligament (ACL) reconstruction. Materials and methods: this study is a randomized and blind clinical trial. Forty-four male volunteers (average age of 27,4 ±6,2 IMC of 26,85± 3,8 Kg/m² and post surgery timeframe of 17± 1,4 weeks) were randomized into two groups: OFF platform (n=22, protocol of exercise over the vibrating platform off) and ON platform (n=22 protocol of exercise over the vibrating platform on, 50Hz frequency and 4mm of amplitude). All volunteers were submitted to assessment the isokinetic evaluation of the quadriceps femoris (isometric and isokinetic at 60°/s) and of the electromyography activity of the muscles Vasto Lateralis (VL) and Vasto Medialis (VM), besides the postural oscillation (baropodometry) in two distinct moments: before and immediately after the intervention protocol. The data was analyzed through the SPSS 20.0 software, with a 5% significance level. To verify the homogeneity of the groups it was used an ANOVA one way, and a ANOVA mixed model to compare the intra and inter groups. Results: it was observed differences between the pre and the post, to latero lateral velocity, isometric torque peak and total work in comparison with intragroup. However, it wasn’t verified any difference in comparing the intergroup in the preevaluation and in the post-evaluation protocol over the vibrating platform. Conclusion: the use of the vibrating platform doesn’t change as an immediate manner the isokinetic performance of the quadriceps femoris, the electromyography activity of the VL and the VM, also doesn’t interfere with the postural oscillation of individuals that were submitted to the ACL reconstruction.

Antecedentes artísticos de la danza "contact improvisation": visiones educativas de los "contacters"

Esta investigación tiene como objeto realizar un estudio de la danza Contact Improvisation (en adelante CI), teniendo en cuenta los antecedentes artísticos; considerar las visiones educativas de los contacters (personas que practican CI); y valorar las posibilidades de la danza CI, considerándola como herramienta útil para la educación. El CI es un envolvente sistema de movimiento iniciado en 1972 por el coreógrafo americano Steve Paxton. Una danza improvisada que se basa en la comunicación entre dos cuerpos que están en contacto y combinan la relación con las leyes físicas que gobiernan el movimiento – gravedad, impulso e inercia. La inquietud de encontrar nuevos caminos que ayuden al desarrollo de una educación más integral partiendo de procesos diferentes a los habituales, es lo que ha motivado este estudio; para ello, se pretende utilizar formas artísticas que aboguen y fomenten la libertad, la sensibilidad y la comunicación de forma creativa. En concreto, buscamos en el CI aspectos que sean favorables para una educación que, a diferencia de la educación reglada, le dé más importancia al desarrollo de la inteligencia emocional...

Didáctica, estrategias y procesos del arte colectivo. Una aplicación didáctica en la enseñanza superior del arte

Dentro de las vanguardias históricas, fundamentalmente las de carácter utópico y con un fuerte compromiso político como el dadaísmo alemán, el constructivismo ruso y el surrealismo francés, podemos localizar una voluntad didáctica de desarrollar una creatividad colectiva y también una recepción colectiva, así como múltiples maneras de hacer que se ponen en común, difuminando las fronteras entre el espectador y el autor, con la clara intención de incidir en la esfera pública. El arte colectivo en las vanguardias se localiza mayoritariamente en amplios movimientos artísticos que involucran un gran número de individualidades y también en sus pretensiones de conseguir unas formas y unas prácticas artísticas que acompañen los movimientos utópicos y revolucionarios y que por tanto puedan ser ejercidas de modo colectivo. Podemos seguir esta voluntad vanguardista en otras experiencias posteriores a la Segunda Guerra Mundial como COBRA, la Internacional Situacionista o Fluxus, para ver cómo se consolidan en los años 80 y 90 con la irrupción de colectivos artísticos, que ya no se organizan en grandes movimientos sino en grupos de afinidad autónomos, con una clara intención activista. Del mismo modo que las vanguardias históricas dirigieron su acción colectiva para integrarse en movimientos activos ligados a los grandes relatos emancipadores de la revolución social, los nuevos grupos de arte y activismo de los años 80 buscarán legitimar sus prácticas en su coalición con los nuevos movimientos de acción política de la posmodernidad, que ya no estarán conformados en torno a aquellos grandes relatos revolucionarios de la modernidad sino que se centraran en las reivindicaciones de las minorías. Y si bien en las vanguardias, lo más habitual, era que los artistas se sumaran a manifiestos y grandes corrientes estéticas, ahora se atomizan en numerosos grupos...

El dossier del artista en Bellas Artes: estudio de casos de la creación y uso en la práctica artística

Esta tesis doctoral se inicia con el Examen de Suficiencia Investigadora, para obtener el Diploma de Estudios Avanzados (DEA), defendido ante tribunal en el año 2011. Desde un principio se comprende que, el dosier del artista en Bellas Artes, sin distinguir el lenguaje de expresión o líneas de investigación del posible autor, está potencialmente vinculado a la actividad artística profesional, en diversos territorios artísticos. Permite enseñar a otros una realidad que no es fácil de demostrar en diferentes contextos y, desarrollado y presentado adecuadamente puede generar positivas relaciones profesionales. Es altamente significativo, para quienes lo elaboran y emplean como medio de comunicación con otros agentes, pero también para quienes lo demandan en el mercado del Arte. Como es el caso de las galerías y los concursos de arte, que actualmente rigen en gran medida su uso y parte de la actividad artística joven profesional. Desde el inicio de la investigación, se encontró información sobre documentos con características similares al dosier del artista, que muestran procesos y trabajos finalizados, pero en áreas profesionales aisladas a las Bellas Artes. Se comprendió que, dichas herramientas no suplían las necesidades en su totalidad con las particularidades del recurso artístico, considerando las diferencias entre los contextos de trabajo correspondientes y las propias características de los documentos. Sólo se localizó un documento que hablaba sobre el dosier del artista, realizado por Gayoso et al. (2007). En éste, el mayor propósito es promover al dosier como un Suplemento al Título Europeo, para el sistema europass. Basado en experiencias de docentes que participan ahí como coautores, y en teorías sobre herramientas académicas de condiciones similares al dosier. Ya que no hallamos gran contenido que contribuya teórica y específicamente al planteamiento de unas pautas generales para la construcción y el uso de un dosier de artista, aquel documento pasa a ser uno de los fundamentos que estructuran y dan vida a esta tesis doctoral. Aunque no se realiza ahí un énfasis sobre el desarrollo y uso del dosier, ello se convierte en la principal finalidad de los sucesivos estudios y análisis para la investigación: encontrar información real y más precisa sobre las características del dosier, su creación y uso...

Desempenho produtivo, classificação e qualidade de carcaça de suínos de diferentes linhas genéticas em engorda intensiva

Compararam-se o ganho médio diário (GMD), índice de conversão alimentar (IC) e classificação da carcaça (CC) entre dois tipos de cruzamento comercial (A e B), ambos obtidos pelo cruzamento terminal de varrascos Piétrain com porcas F1 Large White x Landrace. Procurou-se identificar os principais efeitos ambientais que influenciam os referidos carateres. Utilizou-se um total de 200 suínos (machos e fêmeas), de dois cruzamentos comerciais distintos, provenientes de duas unidades de multiplicação comerciais. Determinou-se o GMD e o IC em dois períodos diferentes (63-119 e 120-158 dias de vida). No final do ensaio, efetuou-se a CC, segundo o sistema SEUROP. Procedeu-se a uma análise de variância com o objetivo de identificar os principais efeitos ambientais que influenciam o GMD, IC e CC. Determinou-se o coeficiente de regressão do GMD no peso vivo no início da engorda. Globalmente, observou-se uma superioridade do cruzado B no que concerne ao GMD (+74,6 g) (p<0,01) e ao IC (-0,07) (p<0,05). O GMD dos animais registou um acréscimo médio de 5,8 g por kg de acréscimo do PV no início do ensaio. A superioridade do cruzado B foi ainda evidenciada na classificação de carcaça SEUROP, com um acréscimo significativo (p<0,01) de 2,3% em carne magra.

Criaturas hipermediales: la posfotografía en Pinterest

Pinterest, la comunidad en línea donde sitúo mi objeto de estudio, permite a sus miembros crear colecciones audio - visuales a partir de imágenes (fijas o dinámicas), vídeos, audios, gráficos e incluso textos encontrados en el universo de internet. El estudio del <> (la unidad audio - visual básica con que se crean estas colecciones y que es confundida con una fotografía digital) es una pequeña red hipermedial conformada por contenidos en formatos de diversa naturaleza con gran potencial para la educación artística y el desarrollo de competencias digitales. El pin, y por extensión, Pinterest, pueden convertirse en herramientas significativas para artistas y educadores, propiciando la utilización de las TIC en los procesos de enseñanza y aprendizaje.

Asumiendo las consecuencias negativas de la adicción al juego

La adicción al juego no sólo se caracteriza por la pérdida de control ante el juego, sino que esta conducta tiende a generar problemas en los diferentes ámbitos de la vida del ludópata. Por ello, este aspecto se recoge en el Manual diagnóstico y estadístico de los trastornos mentales-5 (DSM-V) como uno de los criterios para realizar su valoración diagnóstica. Objetivo: describir y analizar los diferentes elementos que conforman la compleja problemática aparejada a esta adicción y que pueden terminar en situaciones de exclusión social. Método: Se opta por una metodología cualitativa que se ajusta mejor a los intereses del estudio. Como técnica se ha seleccionado la historia de vida, instrumento de evaluación que permite conocer la verdadera magnitud del problema desde el punto de vista de los afectados. Resultados. De manera general, se ha descubierto que ser ludópata tiene muchos más consecuentes que el problema económico evidente. No debemos despreciar las implicaciones de esta conducta a otros niveles: familiar, laboral, legal y social, que pueden considerarse, a medio plazo, como factores mucho más execrables que el del mero gasto económico. Conclusión. Es fácil avistar que los graves problemas que acarrea la adicción al juego son capaces de desmembrar el proyecto vital del ludópata y el de su familia. Todo vale, aunque para ello tenga que jugarse su puesto de trabajo, su casa, su familia, sus amistades, su estatus social y su propia dignidad.

Women, Drug use and Imprisonment. Intersectional Approach

Research on women prisoners and drug use is scarce in our context and needs theoretical tools to understand their life paths. In this article, I introduce an intersectional perspective on the experiences of women in prison, with particular focus on drug use. To illustrate this, I draw on the life story of one of the women interviewed in prison, in order to explore the axes of inequality in the lives of women in prison. These are usually presented as accumulated and articulated in complex and diverse ways. The theoretical tool of intersectionality allows us to gain an understanding of the phenomenon of women prisoners who have used drugs. This includes both the structural constraints in which they were embedded and the decisions they made, considering the circumstances of disadvantage in which they were immersed. This is a perspective which has already been intuitively present since the dawn of feminist criminology in the English-speaking world and can now be developed further due to new contributions in this field of gender studies.

Duelo, ansiedad y depresión en familiares de pacientes en una unidad de cuidados paliativos a los dos meses de la pérdida

Aim: This study is going to assess the prevalance of prolonged grief diagnoses and it will evaluate the severity of the symptoms of depression, anxiety and complicated grief two months after a loved one is lost. We also intend to study which variables associated with the risk of grief could be more decisive when diagnosing it, its symptoms and the consequent emotional distress.Method: A total of 66 families of patients in the Palliative Care Unit (PCU) at Hospital San Cecilio in Granada have been evaluated. Measurements were taken two months after the death. This investigation has explored the existing emotional distress using the following questionnaires: Beck Depression Inventory (BDI-II), Beck Anxiety Inventory (BAI), Inventory of Complicated Grief (ICG) and Prolongued Grief Disorder (PG-12).Results: The results show that 33.3% and 21.21% of the sufferers had high levels of depression and clinical anxiety two months after the death. The prevalence of prolongued grief diagnoses, according to the PG-12, is 10.6% and 53.03% of the participants showed symptoms of complicated grief according to the ICG. Additionally, statistically significant differences are found in the sufferers with and without a prolongued grief diagnosis and scores in the ICG and BDI-II. The family’s financial situation is linked to the presence of symptoms of anxiety and depression and complicated grief, with the most determining variable being the risk of grief. Finally, the greater the age of the deceased and the longer the time spent in the PCU is linked to fewer symptoms of grief. However, important links have been found between the sufferers who have experienced stressful critical events prior to losing their loved one, with symptoms of depression, anxiety and complicated grief.Conclusions: The high numbers of cases of symptoms of complicated grief and levels of anxiety and clinical depression two months after a death suggests that early interventions should be carried out in those individuals with greater vulnerability.