4,079 research outputs found
A direct A.C. to A.C. regenerative frequency and voltage converter
No full textIncludes bibliographical references.The reliable variable speed operation of an a. c. machine over a wide speed range is a problem that has received attention for some time. In this thesis a system to permit such operation from a fixed frequency fixed voltage supply is proposed, under the name of the asynchronous modulation converter. This converter is of the cycloconverter family, but is force-commutated and is not synchronised with the supply frequency. The power switching element comprises a power transistor in a diode bridge, coupled to the control circuitry by opto-isolators. The output of the a-mod converter is produced by a "chopper" modulation process and this results in the harmonics present being at frequencies well removed from the fundamental. A feedback system to ensure smooth commutation of the output current from the power switches is described. This feedback system operates by sensing the rate of rise of the inductive voltage surge on the load when a switch is opened to operate a freewheel path switch
Consultoría organizacional en el Centro Educativo Freire como empresa familiar
No full textReporte del Proyecto de Aplicación Profesional en el que se realizó una intervención en el área de psicología organizacional en el Centro Educativo Freire. Se aplicó la prueba psicométrica Cleaver a los directivos y colaboradores que realizan funciones administrativas y se implementaron programas de capacitación. También se realizaron pruebas de satisfacción a padres de familia, alumnos y docentes con el objetivo de desarrollar planes de acción y estrategias de mejora
Zane Grey with Orange A.C. baseball team
No full textThis photograph shows Ohio native Zane Grey with the Orange A.C. Baseball Team, ca. 1896-1904. Prior to becoming a well-known author of western novels, Zane Grey was also a dentist and a semi-professional baseball player, with teams including the Orange Athletic Club and the Newark (New Jersey) Colts
Educação em saúde na perspectiva da promoção da saúde em grupo de adolescentes
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-graduação em Saúde Coletiva, Florianópolis, 2013.This study focused on health education rooted in the ideas of educator Paulo Freire with the teenagers, from the perspective of health promotion. Adolescents as social actors construct certain way of being in the world, with this conception, the realization of an educational practice participatory and dialogic facing criticism and reflection in a collective favors the transformation of their knowledge, fostering opportunities, among other things, to promote their health. The study aimed to analyze the perception of health among adolescents and the educational experiences which foster participation, autonomy and emancipation. This is a qualitative research, exploratory, descriptive, developed with adolescents participants in the action extension "Dramatizing the Children's Literature" having age between 13 and 14 years, the State School of Abigail Santos Correa in Matinhos - Paraná. The approach of the Circle of Culture of Paulo Freire provided that the subjects had difficulty in verbalizing and participation, although the researcher stimulate critical dialogue and reflective. Data analysis by dialectic hermeneutic possible interpretation and understanding, at the same time the possibility of decoupling and critical. Points out the ethical principles in accordance with Resolution 196/96. From the analysis and discussion of the concepts of the disease process by adolescents, it was found that the process was slow and gradual understanding expanded health to meet the social determination, but the autonomy and emancipation were practically null. Considers the importance of the continuity of actions to foster active, emancipated and autonomous subjects
Tutoria em um curso de educação a distância: contribuições à formação stricto sensu em enfermagem
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-Graduação em Enfermagem, Florianópolis, 2014.A educação a distância é uma modalidade tecnológica e inovadora, a qual vem sendo intensamente utilizada nos cursos de atualização, graduação e pós-graduação, porém ainda são poucos os estudos sobre essa realidade na Enfermagem brasileira. Esse estudo teve como objetivo compreender como a atividade de tutoria de um curso em Educação a Distância contribui à formação profissional de enfermeiros estudantes de pós-graduação stricto sensu. O referencial teórico utilizado foi o autor Paulo Freire. Pesquisa de abordagem qualitativa, caracterizada como um estudo de caso único. A coleta de dados ocorreu em dezembro de 2013, por meio de entrevistas semiestruturadas, realizadas com 17 (dezessete) enfermeiros, que eram tutores de um curso de especialização a distância e alunos de pós-graduação stricto sensu de uma universidade do Sul do Brasil. Após a análise dos dados emergiram três categorias, sendo estas: 1)A prática tutorial, que engloba três subcategorias: Papel do tutor e as atividades desenvolvidas, Abordagens e metodologias utilizadas pelo tutor, Avaliação dos estudantes realizada pelo tutor; 2) Conhecimentos e habilidades necessários ao tutor; e a categoria 3) Contribuições da prática tutorial para a formação stricto sensu, que engloba quatro subcategorias: Reflexão crítica sobre a prática como tutor, Exercício da tutoria no desenvolvimento do Pós-graduando, Tutoria como auxílio para a construção docente, A prática dialógica tutor-aluno no ambiente virtual de aprendizagem. São poucos os estudos, que trazem a realidade da educação a distância na área da enfermagem, sendo necessárias pesquisas, que possam aprimorar metodologias pedagógicas específicas para o processo de ensino e aprendizagem em cursos para formação e qualificação nessa modalidade. Foi possível observar que as atividades tutoriais trouxeram contribuições para o processo de formação de mestres e doutores. Seria interessante que os programas de pós-graduação stricto sensu em enfermagem oferecessem instrumentalização sobre as especificidades desse processo de ensino e aprendizagem aos seus estudantes.Abstract : Distance education is a technological and innovative modality, which has been extensively used in refresher courses, undergraduate and graduate, but there are few studies about the reality of Brazilian Nursing. This study aimed to understand how the activity of tutoring a course in Distance Education contributes to the professional development of student nurses graduate stricto sensu. The theoretical framework used was the author Paulo Freire. Qualitative research approach characterized as a single case study. Data collection occurred in December 2013, through semi-structured interviews with 17 nurses, which are tutors of a specialization course and distance students graduate of stricto sensu in university in southern Brazil. After analyzing the data emerged three categories, which are: 1) A practical tutorial, which includes three subcategories: The role of the tutor and developed activities, Approaches and methodologies used by the tutor, Student Assessment conducted by the tutor; 2) knowledge and skills needed to tutor; and category 3) Contributions of practical tutorial for training stricto sensu, which includes four subcategories: Critical reflection on practice as a tutor, Exercise tutoring in the development of post -graduate student, tutoring aid for teaching construction, dialogic practice tutor -student in the virtual learning environment. Few studies that bring the reality of distance education in nursing, being necessary research that can improve specific teaching methods in the process of teaching and learning in courses for training and qualification in this modality. It was observed that the tutorial activities brought contributions to the process of training masters and doctors. It would be interesting programs for post- graduate studies in nursing offered instrumentation on the specifics of the teaching and learning process for their students
Experimental research on spatial distribution of overtopping
No full textThe overtopping empirical formulas calculate the discharge only at the top of the crest of a coastal protection structure. On the other hand, the tolerable overtopping discharges are defined at certain points behind the crest where the total overtopping is reduced. The scope of this thesis is to find an empirical formula to describe the distribution of overtopping at the space behind the crest. This thesis comes as a further investigation on the work conducted by v.Kester [2009] for regular waves. In this research, a physical model was developed on which irregular waves are tested. Because of the duration of the tests and the amount of collected water (significant lose of water during the test), a completely new measuring system was designed. Five influencing parameters (variables) are considered on this research: wave height, wave period/steepness, slope angle, crest freeboard and crest permeability. The entire overtopping process is analysed separately for the total overtopping discharge, the overtopping discharge directly behind the crest and the distribution of overtopping behind the structure. In the analysis of the data collected from the measurements, the impact of the varying parameters is investigated leading to useful conclusions and better understanding of the entire process. Additionally, the experimental findings are analysed and compared to the relative existing methods. Based on the TAW [2002] method which is proposed by the EurOtop Manual [2007], a prediction formula is developed. This formula is a generic version of TAW [2002] formula in which a new reduction factor ?c is introduced in order to describe the decay of the overtopping and thus predict the discharge at any certain distance behind the crest. Other relevant methods are also analysed (Juul Jensen [1984], Steenaard [2002], Besley [1999] and v.Kester [2009]) and conclusions for their applicability are drawn leading to suggested improvements or corrections. Apart from the distribution of overtopping, on this thesis the determination of crest freeboard (which is an ambiguous issue) is also investigated. Finally, suggestions of further research on this topic are discussed. The entire work has been perfomed in close cooperation with van Oord.Hydraulic EngineeringCivil Engineering and Geoscience
Flow over partially liquid filled cavity
No full textExperiments have been carried out to investigate the effect of liquid cavity filling on the behavior of the gas flow over a flat plate cavity. PIV measurements in the gas phase reveal that cavity filling can affect vortex shedding in the cavity mouth. Shear layer vortices can break-up into smaller vortices, thereby losing their periodic interaction with the aft wall and, hence, their sound producing potential. Expected is that this is one of the mechanisms causing sound mitigation in corrugated pipes with liquid addition, observed in literature
On modular lattices generated by chains
No full textDe La Maza, A.C. (reprint author). Instituto de Matematica y Fisica, Universidad de Talca. Casilla 747, Talca, Chile.We describe the free modular lattice generated by two chains and a single point, under the assumption that there are few meets
Sistemas de gestão em unidades de conservação: o caso dos manguezais da APA de Guaraqueçaba/PR
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas. Programa de Pós-Graduação em Sociologia Política.A presente pesquisa foi projetada objetivando entender como as mudanças no sistema de gestão da Área de Proteção ambiental (APA) de Guaraqueçaba têm contribuído para o desenvolvimento de estruturas de participação social mais equilibradas e assentadas no princípio do compartilhamento de poder e responsabilidades, envolvendo grupo
Quantized current steps due to the a.c. coherent quantum phase-slip effect
No full text| openaire: EC/H2020/862660/EU//QUANTUM E-LEAPS Funding Information: This work was supported by European Union’s Horizon 2020 Research and Innovation Programme under grant agreement no. 862660/QUANTUM E-LEAPS and Engineering and Physical Sciences Research Council (EPSRC) grant no. EP/T004088/1. Publisher Copyright: © 2022, The Author(s), under exclusive licence to Springer Nature Limited.The a.c. Josephson effect predicted in 19621 and observed experimentally in 19632 as quantized ‘voltage steps’ (the Shapiro steps) from photon-assisted tunnelling of Cooper pairs is among the most fundamental phenomena of quantum mechanics and is vital for metrological quantum voltage standards. The physically dual effect, the a.c. coherent quantum phase slip (CQPS), photon-assisted tunnelling of magnetic fluxes through a superconducting nanowire, is envisaged to reveal itself as quantized ‘current steps’3,4. The basic physical significance of the a.c. CQPS is also complemented by practical importance in future current standards, a missing element for closing the quantum metrology triangle5,6. In 2012, the CQPS was demonstrated as superposition of magnetic flux quanta in superconducting nanowires 7. However, the direct flat current steps in superconductors, the only unavailable basic effect of superconductivity to date, was unattainable due to lack of appropriate materials and challenges in circuit engineering. Here we report the direct observation of the dual Shapiro steps in a superconducting nanowire. The sharp steps are clear up to 26 GHz frequency with current values 8.3 nA and limited by the present set-up bandwidth. The current steps were theoretically predicted in small Josephson junctions 30 years ago5. However, unavoidable broadening in Josephson junctions prevents their direct experimental observation8,9. We solve this problem by placing a thin NbN nanowire in an inductive environment.Peer reviewe
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