DC Bus Stabilization and Dynamic Performance Improvement of a Multi-Converter System

Evolution of semiconductor devices is allowing to implement power electronics technology in a variety of applications, moving traditional AC systems to more efficient and reliable DC systems. Some examples are shipboard power distribution systems, DC microgrids, electric vehicles and more electric aircrafts. Even though these types of systems offer significant advantages that make them attractive in different areas, the interconnection of feedback-controlled power converters leads to emergent dynamic behavior that a system designer must take into account to ensure proper operation of the system. Additionally, system reconfiguration is very likely to happen in applications such as a shipboard power distribution, where the loads and sources may change depending on the current mission or in case of contingency. In these cases, system dynamics will change and the overall stability may be compromised. Several criteria can be found in the literature to evaluate system stability. More recently, it was shown that the DC bus impedance can be used for this purpose, overcoming some limitations that other criteria had. Additionally, system identification can be used to monitor the bus impedance. However, there is still a need for a method to evaluate the dynamic performance to guarantee that sudden changes in the system will not affect the DC distribution bus significantly. Active and passive stabilization methods can be implemented to allow for the plug-in capability of new converters to increase the size of the system without compromising the overall stability of the power distribution system. One approach is to implement Positive Feed-Forward control on a load side converter, which introduces a virtual damping impedance at the DC bus. A proper design approach for this damping impedance that will ensure a good stability margin is needed. To address these challenges, firstly a modelling approach that facilitates obtaining the transfer functions of a multi-converter system is presented. Second, a simplified model of the bus impedance will be developed that will allow to evaluate the system when it undergoes reconfiguration and to take fast corrective actions when they are needed. Third, a design procedure for the required damping impedance based on the bus impedance dominant poles will be proposed. And last, an adaptive and distributed stabilizing controller will be presented to account for changes in the load demand

Construir el diálogo científico en la Matemática: la búsqueda del equilibrio entre símbolos y palabras en artículos de investigación sobre Teoría de Juegos

Maestría en Inglés con Orientación en Lingüística AplicadaMost scientific communication is conducted in English, which may be a difficult task and a source of obstacles for researchers whose primary language is not English (Bitchenera & Basturkmen, 2006; Borlogan, 2009; Duff, 2010; Matsuda & Matsuda, 2010). As a matter of concern for language scholars, this situation requires at least two actions: (1) the development of research focused on the problems faced by researchers when writing in a foreign language, and (2) the design and implementation of pedagogical and didactic programmes or services aimed at providing researchers with the tools to enhance their linguistic and rhetorical skills. In both cases, the ultimate objective of these lines of action is to help researchers integrate into and interact with their knowledge communities in an independent, active and successful way. Considering those needs and the emerging interest in English as a lingua franca or as an international language, many scholars have devoted to studying the features of writing and language use across the world and across disciplines (Hyland, 2004; Matsuda & Matsuda, 2010; Mercado, 2010). However, few have explored the case of Mathematics (Lemke, 2002; Morgan, 2008; O’Halloran, 2005; Schleppegrell, 2007), and even fewer have investigated the discourse of scientific research articles (SRA) in this discipline (Graves & Moghadassi, 2013, 2014). In view of this situation, investigation of the discourse of science in the field of Mathematics (Game Theory - GT) as used in the Institute of Applied Mathematics (IMASL), at the National University of San Luis (UNSL), becomes both an answer to local researchers’ needs and an attempt to contribute to current research in writing, evaluative discourse and use of English as an international language for the communication of science. Thus, the main objective of this work is to conduct a comparative description between unpublished GT SRAs written in English by IMASL researchers and published GT SRAs written in English by international authors, in terms of linguistic features used to build authorship and authorial stance. The exploration of the genre is made from the perspective of the system of Appraisal (Hood, 2010; Martin & White, 2005; White, 2000), with the aid of Corpus Linguistics (CL) tools (Cheng, 2012; Meyer, 2002; Tognini-Bonelli, 2001). The results of this research are expected to be useful for the enhancement of knowledge of language professionals devoted to the teaching of writing as well as translation, proofreading, editing and reviewing services. A further goal is to lay the foundations for the production of didactic material which can potentially be incorporated into writing courses or professional writing, translation, reviewing and proofreading training programmes.Fil: Lucero Arrua, Graciela Beatriz. Universidad Nacional de Córdoba. Facultad de Lenguas; Argentina

Integration of collagen matrices into the urethra when implanted as onlay graft

Objective: To assess the integration of decellularized heterologous collagen matrices into the urethra, when implanted with no cells or when seeded with autologous smooth muscle cells.Materials and Methods: Eighteen New Zealand rabbits were randomly assigned to two groups: Group I (n = 9) - animals undergoing urethral segment resection with interposition of a patch of heterologous collagen matrix seeded with autologous smooth muscle cells; Group II (n = 9) - animals undergoing resection of a urethral segment with interposition of a decellularized heterologous collagen matrix patch. Two animals from each group were sacrificed on postoperative days seven, fourteen and twenty-eight; three animals from each group were sacrificed at the end of three postoperative months. At the end of the third month one animal from each group underwent urethroscopy for urethral integrity assessment and one animal from each group had its microcirculation image captured by a SDF device (Side-stream Dark Field - Microscan Analysis Software). One animal from each group in each euthanasia period underwent cystourethrography so as the urethra could be viewed at flow time. the matrices integration was assessed through histological examination using hematoxylin and eosin (H&E), Masson trichrome (MT), Picrosirius red and Von Willebrand staining. in a blind study with two pathologists all the slides were studied.Results: the matrices whether seeded or not with autologous muscle cells were able to restore the architecture of the urethra, but were eliminated from the first week on, before incorporation. Microcirculation of the neourethra, at the end of the third month, showed the same characteristics as a normal urethra in both groups of animals.Conclusion: Natural heterologous matrices implanted in the urethra as onlay graft were not incorporated into its walls but were able to fully restore the cell architecture of the organ, regardless of being seeded or not with autologous muscle cells.Universidade Federal de São Paulo, Dept Surg, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Nephrol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Surg, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Nephrol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, São Paulo, BrazilWeb of Scienc

DrDMembangun Karakter Anak Usia Dini Melalui Metode Bercerita Untuk Anak Usia 5-6 Tahun Di Kelompok Bermain Getsemani Samarinda

Character values are very important for students at the school level, especially for young children. One method that can be used to implement character education is storytelling. Therefore, this research was conducted with the aim of understanding how to build character and what strategies can be used to develop the character of children aged 5-6 years through storytelling using storybooks at KB Getsemani. This research employed a qualitative descriptive method, with data collected through interviews with classroom teachers, the principal, and parents. In addition to interviews, observations and documentation were also carried out to gather data. The analysis technique involved data reduction, data presentation, and drawing conclusions. Based on the research on building character education through storytelling for children aged 5-6 years at KB Getsemani, the results show that teachers have implemented storytelling methods along with certain steps. These steps were then evaluated using a rubric for assessing the implementation of storytelling in class. The results showed that 93% of the process aligned with the assessment guidelines. Moreover, the strategy used, namely the empirical learning strategy, also successfully influenced the children to remember and connect the activities with stories of goodness because it was done creatively and was not boring. From these results, it can be concluded that the application of the storytelling method and the use of empirical learning strategies succeeded in developing the character of children aged 5-6 years at KB Getsemani

Escolha por casas de parto: um estudo sobre estilo de vida e empoderamento feminino

O cenário do parto foi se transformando ao longo do tempo, de modo a despertar a reflexão sobre como as novas gerações estão chegando ao mundo e qual o impacto dessa experiência para a família de um momento tão importante e singular na vida. O estudo objetiva compreender a escolha pela Casa de Parto para o nascimento de um novo ser, e sua relação com o estilo de vida da família. Ao considerar estilo de vida, a perspectiva adotada na Psicologia Ambiental, é descrita como um conjunto de hábitos, valores, crenças que influenciam as ações do dia a dia, a organização do cotidiano das pessoas. Portanto, pode-se compreender que o estilo de vida permeia nossas escolhas (Bassani, 2012), e possivelmente, como parir. Trata-se de uma pesquisa qualitativa, com 9 participantes (sendo 3 casais e 3 acompanhantes do parto), com os quais foram realizadas conversas temáticas para discutir crenças, valores e comportamentos que fazem parte do estilo de vida e que poderiam embasar a escolha do parir em Casa de Parto. Considerando a relação pessoa-ambiente nesse evento da vida, foi proposta a análise dos resultados com base na Logoterapia e Análise Existencial, para discutir a simbologia e o sentido de espaços de humanização do nascimento na contemporaneidade brasileira. Os resultados foram divididos em 5 eixos temáticos: 1) O parto é meu: Protagonismo na Escolha (Influência); 2) Sei parir e meu bebê sabe nascer: Empoderamento para o Parto (Preparação); 3) Lembrarei para sempre: Símbolos Sagrados do Parir (Vivência); 4) Acolhimento: Ambiente para Parir; 5) O imprevisível: Legado da Experiência (Elaboração). A discussão propôs abordar os aspectos relatados que contribuem, modificam e influenciam a experiência sagrada do nascimento, que possibilitam o desvelamento das formas de fortalecer a maternidade consciente e dialogar sobre a realidade obstétrica do país em seu impacto na contemporaneidade. Este estudo está vinculado ao projeto institucional: “Desafios na saúde mental: sustentabilidade e subjetividade no mundo contemporâneo”, CNPq, processo de outorga nº 130105/2022-8The birth scenario has changed over time, in order to spark reflection on how new generations are arriving into the world and the impact of this experience on the family at such an important and unique moment in life. The study aims to understand the choice of the Birth Center for the birth of a new being, and its relationship with the family's lifestyle. When considering lifestyle, the perspective adopted in Environmental Psychology is described as a set of habits, values, beliefs that influence day-to-day actions and the organization of people's daily lives. Therefore, it can be understood that lifestyle permeates our choices (Bassani, 2012), and possibly, how to give birth. This is a qualitative research, with 9 participants (3 couples and 3 birth companions), with whom thematic conversations were held to discuss beliefs, values and behaviors that are part of the lifestyle and that could support the choice of the give birth in a Birth Center. Considering the personenvironment relationship in this life event, an analysis of the results was proposed based on Logotherapy and Existential Analysis, to discuss the symbolism and meaning of spaces for the humanization of birth in contemporary Brazil. The results were divided into 5 thematic axes: 1) The birth is mine: Protagonism in Choice (Influence); 2) I know how to give birth and my baby knows how to be born: Empowerment for Childbirth (Preparation); 3) I will remember forever: Sacred Symbols of Birth (Experience); 4) Reception: Environment for Giving Birth; 5) The unpredictable: Legacy of Experience (Elaboration). The discussion proposed to address the reported aspects that contribute, modify and influence the sacred experience of birth, which make it possible to unveil ways to strengthen conscious motherhood and discuss the country's obstetric reality and its impact on contemporary times. This study is linked to the institutional project: “Challenges in mental health: sustainability and subjectivity in the contemporary world”, CNPq, registered in grant process nº 130105/2022-8Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNP

Florentin Gimenez's Concerto for Violin and Orchestra in D major: Tracing the strings of Paraguayan folk and Western classical styles

In this project I analyze Florentín Giménez's Concerto for Violin and Orchestra in D major. I consider Giménez’s background as a Paraguayan folk musician as well as his immersion into Western classical forms later in life and trace elements from both worlds in this piece. At this point, there have been a total of four performances of the piece. I am doing a comparison between three different versions of the concerto, sharing my critical edition of the solo part and a list of suggested corrections to the score. A tribute to the composer is included at the last section of this paper. With a life dedicated to the development of music and musicians of his country, Giménez was a crucial influence in the musical careers of numerous Paraguayans. A few of them agreed to share a few words in his honor.Ope

Identificación y caracterización proteómica de Aspergillus sp. por MALDI-TOF MS y técnicas de preservación de hongos en colecciones de cultivos

Los hongos del género Aspergillus son los principales contaminantes de granos y cereales en condiciones de almacenamiento. Algunas especies de Aspergillus además de causar deterioro del alimento también producen micotoxinas, que son hepatotóxicas, teratógenas y carcinógenas para los humanos y animales. Siendo así es muy importante identificar a nivel de especies y caracterizar el potencial toxigénico de los hongos de dicho género. El objetivo de la estancia fue la capacitación en la caracterización proteómica e identificación de Aspergillus aislados de maíz por espectrometría de masa del tipo MALDI-TOF y asociar a la características morfológicas, fisiológicas y moleculares para obtener una taxonomía con enfoque polifásico, que es lo más actual recomendado para dichos hongos. Además, me capacité en algunas técnicas de preservación, mantenimiento y gestión de datos de cepas de microorganismos en colecciones de cultivos con el objetivo que no pierdan su viabilidad y sirvan para futuros estudios en diferentes áreas, además de estar conservando la biodiversidad local. Todo el conocimiento adquirido fue difundido y servirá de base para futuras investigaciones en la problemática de hongos productores de micotoxinas. Considero también que dicha vinculación fue muy importante para fortalecer el intercambio científico y cultural entre diferentes universidades, permitiendo el establecimiento de redes científicas multidisciplinarias en el área de caracterización de hongos e inocuidad alimentaria.PROCIENCIACONACY