bluuebunny/crossref_metadata_2025 huggingface dataset:
Editorial
Authors: Melo Junior João Carlos
Published: April 2017

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Produção de serapilheira em dois manguezais do estado do Paraná, Brasil
Authors: Larcher Letícia , Torres Boeger Maria Regina , Nogueira Guilherme , Reissmann Carlos Bruno
Published: April 2017

Serapilheira é a camada formada pela deposição e pelo acúmulo do material proveniente das espécies vegetais e representa a maior contribuição da entrada de nutrientes nos ecossistemas de manguezal. As variações encontradas na produção desse material são resultantes da ação de diferentes fatores ambientais e intrínsecos das espécies. Este estudo teve como objetivo estimar e comparar a produção da serapilheira de dois bosques de mangue no estado do Paraná, com diferentes padrões estruturais. Foram instalados 15 coletores em cada área, e realizaram-se as coletas mensalmente. Em ambas as áreas, a fração folhas foi o principal componente da serapilheira, seguida por ramos, material reprodutivo e miscelânea. As espécies apresentaram maior deposição de folhas e material reprodutivo nos meses com maior temperatura e maior precipitação. A salinidade parece ser o fator que mais influencia a produção total de serapilheira, resultando em uma baixa produtividade anual quando comparada com outras áreas de latitudes semelhantes.
Comunidade de abelhas (Hymenoptera, Apidae) e plantas associadas em área de mata atlântica em São Francisco do Sul, Santa Catarina, Brasil
Authors: Mouga Denise Monique Dubet da Silva , Nogueira-Neto Paulo , Warkentin Manuel , Feretti Vanessa , Dec Enderlei
Published: April 2017

A comunidade de abelhas nativas em uma área de mata atlântica no sul do Brasil foi estudada no período 2001-2003, utilizando-se rede entomológica em plantas floridas. Foram amostrados 1.519 indivíduos de 80 espécies e 4 subfamílias de abelhas. Houve predomínio de espécies de Apinae não corbiculadas e Halictinae e de indivíduos de Apinae corbiculados e Halictinae. As plantas associadas totalizaram 124 espécies de 46 famílias, das quais as mais visitadas foram Asteraceae, Fabaceae, Lamiaceae e Melastomataceae. Foram amostradas 11 espécies de abelhas não assinaladas para Santa Catarina. As abelhas mais amostradas foram Apis mellifera, Trigona spinipes, Bombus morio, Dialictus sp., Augochloropsis sp. 07, Trigona braueri, Augochlora (Oxystoglossella) sp. 05 e Tetragonisca angustula. A quantidade de indivíduos amostrados por mês, ao longo do período de coleta, evidencia um padrão bivoltino (maio e setembro-novembro). Algumas espécies de plantas foram visitadas apenas por Apis mellifera. Os índices de diversidade e equabilidade ficaram em 2,315 e 0,528, respectivamente. A curva de acumulação mostrou-se crescente. Os estimadores de riqueza apontam mais espécies. A riqueza e a abundância evidenciam um padrão de atividade de clima temperado. A composição da apifauna demonstrou maior similaridade com formação de floresta ombrófila densa de terras baixas.
Chuva de sementes em fragmentos de mata atlântica do Parque Estadual da Cantareira, Mairiporã (SP)
Authors: Almeida Junior Paulo Alves de , Barbosa José Marcos
Published: April 2017

A chuva de sementes é um processo importante para determinar a dinâmica e os tipos dedispersão dos diásporos. Visando compreender os processos envolvidos para as espéciesocorrentes no Parque Estadual da Cantareira, Mairiporã (SP), objetivou-se caracterizar a chuvade sementes das populações locais em dois fragmentos de floresta. Foram confeccionados20 coletores de madeira, sendo distribuídos cinco na Trilha do Macuco e 15 na Trilha daCachoeira. Avaliaram-se mensalmente, pelo período de um ano, as densidades de propágulosdepositados nos coletores, sendo esses propágulos identificados e categorizados com base nasua síndrome de dispersão e na sua classe sucessional. Realizaram-se as análises estatísticasem relação a distribuição de sementes, frequências relativas, densidade e densidade relativados táxons identificados, com o software Microsoft Excel 2010 para Windows. Com relaçãoàs síndromes de dispersão e classes sucessionais, houve predominância da síndromezoocórica e de espécies de classes sucessionais secundárias. A quantidade e a riqueza dediásporos amostrados foram elevadas, considerando-se os padrões de floresta atlântica. Asespécies mais abundantes e presentes na maioria das parcelas foram Cordia americana (L.)Gottschling J.S.Mill., Vernonia discolor (Spreng.) Less. e Serjania multiflora Cambess.
Florística e fitossociologia do componente arbóreo de um fragmento de floresta ombrófila densa do estado de São Paulo
Authors: Guedes Juliana , Krupek Rogério Antonio
Published: April 2017

Este trabalho teve como objetivo avaliar a estrutura horizontal e vertical e a diversidade florística de um fragmento de floresta ombrófila densa por meio de levantamento fitossociológico e florístico. O estudo foi realizado em uma área localizada dentro dos municípios de Alumínio e Mairinque, região sudeste do estado de São Paulo. Os trabalhos de campo foram desenvolvidos durante o ano de 2014, e foi disposto, na área de estudos, um total de vinte parcelas medindo 10 x 50 metros (0,05 ha.), totalizando 1 hectare de área total. Os parâmetros avaliados foram: frequência absoluta, frequência relativa, densidade média, densidade total, densidade absoluta, densidade relativa, área basal, dominância absoluta, dominância relativa, valor de importância e valor de cobertura. Calcularam-se índices de dominância, diversidade e equitabilidade, além da estrutura horizontal e vertical da comunidade. Na área de estudo foram encontradas 81 espécies identificadas em 31 famílias botânicas. As famílias com maior abundância foram Myrtaceae (93 indivíduos) e Euphorbiaceae (64), e a família com maior riqueza de espécies foi Fabaceae (7 espécies).Em relação aos dados fitossociológicos, o táxon Eucalyptus sp. foi o que apresentou maior densidade e dominância, sendo considerado o de maior valor de importância da área. A espécie Croton floribundus ficou em segundo lugar em valor de importância. As famílias àsquais pertencem as espécies mencionadas são características de floresta ombrófila densa. A maioria das espécies apresentou média de DAP 19,7 cm e altura média de 14,7 m. Foram encontradas 16 espécies raras. Palavras-chave: Distribuição espacial; diversidade; estrutura horizontal e vertical.
Análise da fragmentação de hábitats em municípios da bacia hidrográfica do Rio Tijucas e municípios conexos à REBio da Canela Preta – Santa Catarina
Authors: Granato de Souza Daniela , Iza Oscar Benigno
Published: April 2017

A análise da fragmentação de hábitats auxilia na eficácia de ações que evitem a perda significativa de florestas conservadas. Os municípios integrantes e contíguos à bacia hidrográfica do Rio Tijucas, em Santa Catarina, possuem bons remanescentes florestais em estádios preservados, e essa região conta ainda com a presença da REBio da Canela Preta, importante fonte de biodiversidade. O objetivo deste trabalho foi identificar os motivos que levaram os proprietários de terras ao desmatamento ilegal de florestas nativas dessa região. Foram analisados os processos administrativos ambientais referentes à flora nativa, ocorridos durante o período de 2007 a 2011, nos quais se observou o registro de grande perda da cobertura florestal (121,45 ha.). Mais de 50% das florestas impactadas encontravam-se emestádios médio e avançado de regeneração antes do desmate. Em 74,4% das áreas desmatadas, foram realizados, a posteriori, reflorestamentos com a espécie exótica Eucalyptus sp., com tamanho médio de 0,15 ha., comprovando ser a opção econômica dos pequenos produtores rurais. Verificou-se também a incidência de intervenção antrópica em áreas de preservação permanente. Espera-se que a apresentação desses dados contribua para identificar as causas da fragmentação de hábitats na região, direcionando a criação de políticas públicas que abordem o problema, com enfoque para a bacia hidrográfica.Palavras-chave: Desmatamento ilegal; mata atlântica; reflorestamento.
A reconstrução do significado da teoria preditiva do Direito a partir das ideias fundamentais do pragmatismo neoclássico
Authors: Leite Matheus De Mendonça Gonçalves
Published: April 2017

Este artigo reconstrói as ideias fundamentais do pragmatismo clássico, com o intuito de lançar luzes sobre a teoria preditiva do Direito de Oliver Wendell Holmes Jr. O pragmatismo clássico é uma corrente filosófica que utiliza as ideias científicas prevalecentes no final do século XIX, para a construção de uma teoria compreensiva do universo e de um método científico. Assim, as ideias da evolução e da experiência foram sintetizadas na máxima pragmática de Charles Sanders Peirce. A partir da revisão bibliográfica dos principais textos do pragmatismo clássico e da correspondência trocada entre os principais pragmatistas, constata-se que Holmes faz uso das ideias fundamentais do pragmatismo, com o intuito de construir uma teoria compreensiva do Direito. Assim, a teoria preditiva do Direito é o resultado da aplicação da máxima pragmática na compreensão/explicação do fenômeno jurídico, bem como na construção de um método científico para o desenvolvimento e crescimento do Direito. Contudo, a teoria preditiva do Direito foi, com muita frequência, mal interpretada por autores, que, desconsiderando a sua relação com a máxima pragmática e pinçando de modo descontextualizado algumas frases de Holmes, constroem a falsa imagem de que o Direito é um produto das escolhas arbitrárias dos juízes. Assim, a partir de sua relação com a máxima pragmática, mostra-se que a teoria preditiva fornece um método científico de desenvolvimento do Direito que o adapta à satisfação das necessidades sociais.
A POLIFONIA E O PRINCÍPIO DO CONTRADITÓRIO: as vozes do processo em dialogia
Authors: De Oliveira David Barbosa
Published: April 2017

RESUMO: Esse artigo utiliza metodologia eminentemente bibliográfica e busca lançar luz sobre o princípio do contraditório em sua acepção substancial, ou seja, para além da simples participação no processo. Ante esse objetivo, importa entendermos como, por meio do princípio do contraditório, as partes no processo devem ser ouvidas e ter seus argumentos levados em consideração no ato decisório pelo julgador. Nesse diapasão, urge levar em consideração a colaboração que o dialogismo pode aportar para a melhor compreensão desse princípio. Assim, encontramos como resultado as contribuições que os estudos da linguística, especificamente o dialogismo de Bakhtin, possibilitam para que o processo seja visto como efetivo diálogo entre todos os partícipes do processo, incluindo então o magistrado e o parquet, afastando assim a escuta surda e a consequente reificação dos sujeitos do processo.
O RINOCERONTE DE DÜRER
Authors: Lelis Davi Augusto Santana de
Published: April 2017

Realiza-se uma reconstrução da história da filosofia, utilizando-se a alegoria do rinoceronte de Dürer para identificar como se estrutura o sistema jurídico. Identifica-se que o Direito ainda se fundamenta em uma lógica epistemológica que busca a representação da realidade por meio da categorização dos institutos e indivíduos em normas. Como proposta, apresenta-se uma alternativa filosófica para o pensamento jurídico: a ética da alteridade. Analisa-se, também, alguns exemplos atuais de categorização do direito.
Influencia, por selección, de América en su arte colonial
Authors: González Galván Manuel
Published: April 2017

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La estampa como fuente del arte en la Nueva España
Authors: Manrique Jorge Alberto
Published: April 2017

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Observaciones acerca de las artes plásticas en las publicaciones periódicas de José Antonio de Alzate y Ramírez
Authors: Ramírez Fausto
Published: April 2017

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Las mujeres artistas en México
Authors: Eder Rita
Published: April 2017

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Picasso en Barcelona
Authors: Azuela Alicia
Published: April 2017

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Viaje a México (1844)
Authors: Díaz y de Ovando Clementina
Published: April 2017

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El pianismo mexicano del siglo XIX
Authors: Velazco Jorge
Published: April 2017

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Presentación
Authors: Las editoras .
Published: April 2017

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"Carta a un tal barón von…” de W. A. Mozart sobre el proceso creativo
Authors: García Gómez Arturo
Published: April 2017

El artículo trata sobre la concepción romántica del “genio creador”, mediante el análisis de una carta atribuida a Wolfgang Amadeus Mozart, escrita en 1791. La carta la publicó Johann Friedrich Rochlitz el 23 de agosto de 1815 en la Allgemeine Musikalische Zeitung de Leipzig, y desde entonces ésta ha sido el centro de atención de filósofos, historiadores y musicólogos. Su interés se centra en el proceso de la creación musical y en cómo el “genio creador”, el compositor, percibe mentalmente la obra musical ya terminada antes de escribirse. Mi objetivo es mostrar, en el análisis de esta carta, las limitaciones del racionalismo musical que no ve más allá de la partitura, creyendo que la música se encuentra en las notas o en sus relaciones numéricas bajo una percepción visual y arquitectónica.
Presencia del héroe homérico en el Vaso François
Authors: Alhim Rodríguez Marysol
Published: April 2017

Con base en la teoría de la identidad cultural en el arte o teoría del arte como sistema cultural presento un análisis mítico-literario de las múltiples escenas pictóricas plasmadas en el complejo y controvertido Vaso François, las cuales relaciono temáticamente entre sí. A partir de allí, sugiero que deben estudiarse como un “todo” y en relación con la forma de la pieza en que se plasmaron y no como mitos aislados, postura encaminada a argumentar que el vaso en cuestión tiene una unidad iconográfica y formal, pensada de antemano, cuyo paradigma o hilo conductor es el héroe homérico y sus tópicos más significativos.
Escultura, modernismo y Academia: interrelaciones entre la enseñanza, el discurso estético oficial y la escultura modernista en Barcelona (1888-1910)
Authors: Gras Valero Irene , Rodríguez Samaniego Cristina
Published: April 2017

El presente artículo se ocupa de la relación entre la escultura pública y la Academia de Bellas Artes de Barcelona en la época de configuración del modernismo catalán. Se busca aportar una visión renovada de la academia del momento, al cuestionar la idea de que ésta fue impermeable a las corrientes innovadoras que aparecieron en el mundo occidental de finales del siglo XIX y principios del XX. El artículo aborda un enfoque poco habitual en el aspecto historiográfico, en el que el discurso estético emitido por la academia tiene un papel importante, y en el cual se propone una revisión de lo académico y del academicismo en su relación con la escultura, aplicable a otros contextos geográficos.
Mining Photography: The Oficina Alianza and Port of Iquique 1899
Authors: Purbrick Louise
Published: April 2017

En 1899, el señor Smail, representante de la casa mercantil británica Antony Gibbs and Sons en Chile, envió el álbum de fotografías Oficina Alianza and Port of Iquique 1899, al propietario de la compañía, Henry Hucks Gibbs. Este artículo ofrece un análisis del imaginario fotográfico del álbum, en particular de las convenciones de la fotografía industrial en la representación de la minería de nitrato en Chile y del cuerpo del minero en el momento de trabajar. El artícu-lo considera también la función del álbum fotográfico en la industria de nitrato y su papel en la circulación y el tráfico comercial de nitrato entre Chile y Gran Bretaña.
Jorge Alberto Manrique (1936-2016)
Authors: Estrada Julio
Published: April 2017

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Development of 8 MVA class Power Stack for Offshore Wind Power Conversion
Authors: Jin-Hong Kim  , Joon Sung Park  , Chung-Yuen Won
Published: April 2017

Offshore wind power generation is one of the viable solutions for the safety of energy consumption, and the growing concerns for environmental protection and the petroleum crisis. The advantages of wind power generation which are comparatively stable wind speed in the sea, fewer developing interest relative sides, and non-trying for land with other projects, large scale of offshore wind farm building becomes a new trend for wind power industry. Offshore wind power can becomes a viable alternative only if that is able to meet certain reliability, performance, and cost criteria. In this paper, the authors developed and evaluated power stack by considering their influence on the performance. The evaluations is demonstrated experimentally
Modeling and Analysis of Wave Power Generation using Permanent Magnet Linear Synchronous Generator
Authors: Joon Sung Park  , Jun-Hyuk Choi  , Gyung-Sun Ham  , Jong-Su Choi  , Junbo Yun  , Ju Lee
Published: April 2017

This paper describes ocean wave power generation by using permanent magnet linear synchronous generator. The preliminary analysis has shown that a linear generator enables substantial simplification of the mechanical system with respect to a dc generator case [1]. The linear motor has been adopted, taking into consideration the features of the incident waves and the behavior of the floating buoy. The floating buoy is placed on the ocean surface and connected to the generator. The wave energy is carried out from the movement of a buoy. An electrical conversion system is needed between the generator and the grid. For an analysis of the power system, the modeling of the linear generator and converter system was proceeded. This paper aims at studying the electrical part of the wave energy converter and study what impact the electrical system will have on the generator.
Utilization of Smart Grid and Renewable Energy toward a Sustainable Future in Saudi Arabia
Authors: Alghanim. M.H  , Mallick. P.K
Published: April 2017

Saudi Arabia is currently the largest oil producing and oil-exporting country in the world, but it also has a strong potential for renewable energy, particularly solar energy as it receives a significant amount of sunlight during most of the year. As demand for electricity increases with increasing population, energy becomes one of the main challenges in Saudi Arabia. As a result, infrastructure for different energy resources needs to be developed and integrated smartly into the country’s electricity grid. This paper discusses the reasons to implement smart grid in Saudi Arabia, and the challenges and opportunities of utilizing renewable energy in conjunction with smart grid.
Technical and economic assessment of energy from Tidal Currents
Authors: Isabel Páscoa  , C. Camus  , E. Eusébio
Published: April 2017

The present work aims to study the feasibility of deploying a farm of sea current turbines for electricity generation in Portugal. An approach to the tides, which are they, how they are formed, its prediction, is held. It is also conducted a study about the energy of sea currents and it is presented some technology about ocean currents too. A model of tidal height and velocity of the currents it is also developed. The energy produced by a hypothetical park, built in Sines (Portugal), is calculated and afterwards, an economical assessment is performed for two possible scenarios and a sensitivity analysis of NVP (Net Present Value) and LCOE (Levelized Cost of Energy) is figured. The conclusions about the feasibility of the projects are also presented. Despite being desired due to its predictability, this energy source is not yet economically viable as it is in an initial state of development. To push investment in this technology a feed-in tariff of, at least €200/MWh, should be considered
Renewable Energy in Islands. An Integrated Proposal for Electricity Generation and Transports
Authors: P. Marques  , E. Silva  , C. Camus  , E. Eusébio
Published: April 2017

The purpose of this article is to analyse and evaluate the economical, energetic and environmental impacts of the increasing penetration of renewable energies and electrical vehicles in isolated systems, such as Terceira Island in Azores and Madeira Island. Given the fact that the islands are extremely dependent on the importation of fossil fuels - not only for the production of energy, but also for the transportation’s sector – it’s intended to analyse how it is possible to reduce that dependency and determine the resultant reduction of pollutant gas emissions. Different settings have been analysed - with and without the penetration of EVs. The Terceira Island is an interesting case study, where EVs charging during off-peak hours could allow an increase in geothermal power, limited by the valley of power demand. The percentage of renewable energy in the electric power mix could reach the 74% in 2030 while at the same time, it is possible to reduce the emissions of pollutant gases in 45% and the purchase of fossil fuels in 44%. In Madeira, apart from wind, solar and small hydro power, there are not so many endogenous resources and the Island’s emission factor cannot be so reduced as in Terceira. Although, it is possible to reduce fossil fuels imports and emissions in 1.8% in 2030 when compared with a BAU scenario with a 14% of the LD fleet composed by EVs.
Solar and Wind powered Stand Alone Water Pumping system
Authors: Arruda. M. F. D  , Carvalho. P. C. M.  , Albiero, D. J  , Canafistula, F.J.F  , Teixeira, A. S.
Published: April 2017

The   purpose   of   the   article   is   to   verify   the performance  of  a  wind  and  photovoltaic  (PV)  hybrid  plant  with battery  bank  for  water  pumping.  The system  can  be used  inisolated areas without access to electricity grid. The  plant  is  installed  at  the  Federal  University  of  Ceará,  in Fortaleza,  Brazil.  The  plant  consists  of  a  wind  turbine  (1  kW  - permanent  magnet)  and  4  polycrystalline  PV  modules  (87  Wp each),   5   batteries   (150   Ah   each)   and   1   power   electronic converter  (1  kW).  A  datalloger  is  used  for  acquisition  and storage  of  data  (wind  speed,  global  irradiance,  water  flow  and electrical  data).  The  present  study  uses  data  from  four  non-consecutive days  in  November/2014 and December/2014; in the first day only PV and the battery bank supply the load.    The   recorded   mean   flow   was   25.26   L/min,   showing   little variation,  even  with  intermittence  of  the  resources,  condition minimized  by  the  energy  storage.  As  a  consequence  of  the energy  storage,  the  hybrid  system  shows  low  operation  request, enhancing  the  life  cycle  and  consequently  reducing  the  plant replacement costs.
Efficient Reciprocating Internal Combustion Engine Operating Under a Regenerative Isobaric Expansion Based Cycle
Authors: R. Ferreiro-García  , R. Borrás-Formoso  , J. Carbia-Carril
Published: April 2017

The work deals with a novel regenerative trilateral internal combustion engine cycle (RTICC) which differs from the conventional Carnot derived thermal gas cycles in that energy absorption and conversion into mechanical work is performed in a single process between two state points of the cycle under an operating pressure which balances the reaction load, so that for a constant load this path function is isobaric. While thermal energy is being absorbed along the expansion process, internal energy, enthalpy, specific volume and entropy increases as mechanical work is delivered. The analysis of the cycle is presented and results are compared with Carnot factor which conventionally has been considered as a benchmark for all thermal engine cycles. The results show that a relevant advantage of the proposed cycle deals with performance enhancement into a wide range of combustion temperatures. The successful results associated with a compact and simple engine structure, and economically viable, promises a new generation of efficient internal combustion engines.
ESTIMATE OF AVERAGE ENERGY GENERATED IN A RIVER BASIN BY STATISTICAL ANALYSIS FOR SMALL HYDROPOWER PLANTS
Authors: J. H. I. Ferreira  , J. A. Malagoli  , J. R. Camacho
Published: April 2017

aspects analyzed during the first stage of the deployment of a small hydropower in Brazil, the Estimate of Hydropower Potential. In this scenario, knowledge of water availability is a fundamental part of the hydrologic studies of a river basin, studies pertaining to the stage of the cycle to determine the flow of a river or precipitation in a location or region, including its temporal variability. In this context, this work has the objective to perform a statistical analysis to determine the values of the variables that affect the calculation of the average energy: a reference flow, the average monthly flows and the permanence curve. It was used the data from streamflow time series 1942-2013 of the river Tijuco, in the state of Minas Gerais. In the analysis of the variables, it was necessary to know and study agencies and legislation, a probabilistic model and computational tools to help determine the values. It was found that the statistical hydrology in the process of estimating the average power for hydroelectric projects provide reliable data and that the interpretation of the data can support the decision in the phase of projects
Indicators for assessing sustainability of power plants: environmental, social, economic and technical aspects
Authors: J.J. Cartelle  , M. Lara  , M.P. de la Cruz  , A. del Caño
Published: April 2017

The public is increasingly aware of the problems caused by unbridled development. More and more, governments, companies and other organisations are establishing sustainable development policies for making more likely that future generations can satisfy their own needs. A set of environmental, social, economic and technical-functional indicators are proposed and described here. These indicators are useful to create complete models for assessing the global sustainability of renewable and non-renewable power plants throughout their life cycles. This set of indicators can be useful for engineers, researchers and, in general, decision makers in the energy policy field. This is the first step to achieve more sustainable energy mixes.
Hydrokinetic Micro-Power Generation in Small Rivers - a New Approach
Authors: D. Norta  , S. Ramanathan  , S. Sachau  , H-J. Allelein
Published: April 2017

The so called German electrical “Energiewende” is mainly based on the installation of solar photovoltaic and wind energy converters as the main new renewable European generation resources. The third renewable energy resource, the hydropower has been already developed within the last decades and grew not significantly in the last years. Since some years the development of smaller hydrokinetic turbines increased. The smaller size of some hydrokinetic turbines enables new, unused sites to be harnessed in smaller rivers. The paper deals with the key specifications of hydrokinetic turbines and their influence on a villages’ energy supply. It introduces the concept of a turbine with variable immersion depths to exploit also locations with a varying water level. Based on historical hydrological data a propeller and oscillating hydrofoil type of hydrokinetic turbine are compared, it was found that the variable immersion depths increases the energy harvest. Furthermore, it is shown that in a generation portfolio of hydrokinetic and solar power plants an average Luxembourgish household theoretically renewable supplied has to exchange less energy with the power grid, the higher its share of hydrokinetic generation is.
Fault detection and isolation in a photovoltaic system
Authors: M. Muñoz  , A. Correcher  , E. Ariza  , E. García  , F. Ibañez
Published: April 2017

This paper presents a fault detection and isolation method based on identification applied to a PV system. The process has been carried out by analyzing data from a real PV installation coupled with a grid-tied monophasic inverter.
Novel approach for concentrating and harvesting solar radiation in hybrid transparent photovoltaic façade’s in Southern Africa.
Authors: RH Gevers  , JHC Pretorius  , P van Rhyn
Published: April 2017

Electrical consumption and the price thereof is rapidly increasing in South Africa. Finding alternatives to the current grid-tied electricity supply in the country is a prodigious concern to the South African economy due to historic unreliability. The national power grid and the South African economy can extensively benefit from utilizing solar energy as an abundant clean and renewable energy source. This paper considers and further investigates power generation utilising a novel approach to transparent solar façades (windows). Harvesting solar energy is consequently included in the building envelope, which improves building efficiency while reducing demand on the national electric grid. The impacts, design, modelling and results of this novel approach to Photo Voltaic (PV) systems, is further examined in this paper. These systems are aimed to be used in the commercial and residential market. Factoring in the location, design and installation of the solar façade, geographical conditions relevant to South Africa were used to evaluate the transparent façade’s performance. The generated power from a façade depends on solar irradiation, orientation, (Azimuth and Zenith angles); climate conditions such as temperature and rainfall; and other solar constraints. These factors were incorporated using average values from meteorological data.
A Comparative Analysis between Methodologies for Responsibility Assignment on Harmonic Distortions
Authors: A. C. Santos  , J. C. Oliveira  , I. N. Santos
Published: April 2017

A current challenge which emanates from the Power Quality area is the search for a reliable means for sharing the responsibility assignment on harmonic distortions between the parties involved. In fact, to determine the THD (Total Harmonic Distortion) levels for the points of coupling between the suppliers and consumers, the identification of the individual contributions of the parties is presented as information relevant to any mitigating measures. In this context, although in literature there have been some highlighted methodologies, which aim at characterizing portions of responsibility between the agents, due to the subjects concerning the procedures, there are still frequent questionnaires concerning the conclusive contribution from the parties. Thus, this article summarizes the main procedures found in literature and through the implementation of a hypothetical test system that operates under three distinct conditions, a set of performance computational studies are carried out. The studies yield results that are utilized as a comparative and critical base of the methodologies being directed towards the motives described herein, while highlighting their potential along with limitations.
Analysis of the Influences of Changes in Gains and Time Constants in a Power Factor Regulator Using ATP-EMTP
Authors: M.J.B.B. Davi  , J.R.C de Almeida  , C. B. dos Santos  , F. A. M. Moura  , M. V. B. Mendonça  , J.R. Camacho
Published: April 2017

The   objective   of   this   study   is   to   analyze   the influence  of  the  gains  and  time  constants  in  a  control  system  of  a Power  Factor  Regulator.  This  regulator  was  modeled  using  the “TACS –Transients  Analysis  Control  System”  routine  "ATP-EMTP   -   Alternative   Transients   Program".   This   regulator   is connected  to  a  synchronous  machine  of  an  independent  producer, and later, is observed the behavior of machine speed in steady state, the rms  voltage  and  power  factor  is  observed  in  the PCC  (Point of Common Coupling) of the system. Finally, appropriate conclusions about the influence of the gains and time constants for the regulator power  factor is  conducted,  seeking  a  system  that  behaves as  stable as  possible,  taking  into  account  the  rules  related  to  the  insertion of distributed generators in the Electric System.
Comparison of Transmission Technologies with Regard to their Contribution to Power System Stability
Authors: S. Höhn  , A. Semerow  , M. Luther
Published: April 2017

The amount of power to be transmitted is increasing worldwide. Hence, a considerable number of bulk power transmission projects are going to be realized (e.g. [1]). Taking into account the recent technical development, three technologies are available for bulk power transmission: Direct current applications with voltage sourced or line commutated converters as well as the high-voltage AC technology up to 1200 kV. To select the most suitable technology for a particular project is often anything but trivial for the transmission system operator. Amongst other criteria, the influence on the electromechanical behavior of the power system is a decisive factor for network improvements that should be considered within the decision-making process. This paper aims at categorizing and analyzing this rather abstract term as a major criterion. The goal is to provide an indication, which factors are needed to be evaluated in advance of the well-considered choice. For that reason, several categories are introduced and thoroughly investigated within the scope of a theoretical approach. Where reasonable, simulation results are presented in order to enable the practical assessment of the impact on the electromechanical system behavior. As a conclusion, it is recommended to perform concise ex-ante studies with regard to the electromechanical dynamics as a decision-making basis to identify the most suitable transmission technology for a particular project.
BRAZILIAN AUTOMOTIVE MARKET AND ENVIRONMENT: AN ANALYSIS OF FIGHTING MEASURES CO2 EMISSION
Authors: Nilcéia Cristina dos Santos  , Reinaldo Gomes da Silva  , Manoel Gonçales Filho
Published: April 2017

The consumption of fossil fuel derived oil has a significant impact on the quality of the environment. Air pollution, climate change, oil spills and toxic waste generation are the result of the use and production of these fuels. Automotive vehicles are among the main contributors to the problem. In Brazil, to combat this environmental pollution, public policy has been implemented to increase the efficiency of vehicles and diversify the use of alternatives to fossil fuels (ethanol and biodiesel) sources. This study proposes to examine measures to combat the emission of carbon dioxide (CO2 ) adopted by Brazil dioxide.
Influence on a Consumer Unit Power Factor Provided by the Connection of a SHPP in Shunt with the Utility Power
Authors: Arnulfo Barroso de Vasconcellos  , Raul Vitor Arantes Monteiro  , Jéssica Romeiro de Carvalho  , Marina Silva Camillo de Carvalho  , Tisciane Perpétuo e Oliveira  , Teresa Irene Ribeiro de Carvalho Malheiro
Published: April 2017

Production growth of agribusiness in the state of Mato Grosso increased the deployment of industries in several regions of the state, regions which the hydraulic potential is favorable to the installation of small hydro power plants (SHPP) that helps in the supply of the active power demand of these consumer units (UC). This article analyzes a consumer unit of Class A customer, relative to the agribusiness, with an industrial park consisting of soybean storage, processing unit of cotton and cottonseed crushing, what was initially only connected to the electric utility bus. After building a SHP with two generators at the UC, this generation was connected in parallel with the power utility bus after the system power measurement. In this work is analyzed the influence of the entrance of SHPP in surplus of UC’s reactive power, discussing the need for parallel generation to operate with the power factor in conformity with the load’s reactive demand requested by the UC of the utility bus to improve the power factor recorded by the measurement system and eliminate the excess of reactive energy on the energy bill, similarly with the effect of a connection of a variable capacitor bank downstream the utility measuring for regulating the power factor seen by the meter.
The Influence of Reactive Flow by Electronic Loads in Electricity Billing System of a Shopping Mall's Consumer Unit
Authors: Arnulfo Barroso de Vasconcellos  , José Mateus Rondina  , Rondina@terra.com.br  , Marina Silva Camillo de Carvalho  , Teresa Irene Ribeiro de Carvalho Malheiro
Published: April 2017

This paper analyzes the use of a set of electronic loads, specifically tubular and compact fluorescent lamps with electronic ballasts in a Shopping Mall, as well as its possible impact on existing rules of charging. In field measurements regarding two transformers that feed two levels of the building, using a power analyzer, was observed a capacitive reactive power flow to the source. This study inquires if this capacitive reactive flow generated by electronic loads is beneficial or detrimental to the charging system, depending on the time of the day that the electronic charge is triggered. Beyond that, this paper provokes discussions about projects of power factor correction in consumers units, that have in its bus the presence of linear and non-linear electronic loads.
Towards a Better Understanding of Harmonics and Power Electronics – New Measurement Results and Analysis Methods for Modern Large-Scale Inverters
Authors: S. Rogalla  , F. Ackermann  , N. Bihler,  , G. Dötter  , R. Singer  , E. Wolf
Published: April 2017

This paper deals with the harmonic current emission of large self-commutated PV inverters. It disproves with new measurement results that modern inverters behave as current sources for harmonic currents, which is the general idea behind the accepted grid codes. Furthermore it presents new approaches to quantify the contribution of grid voltage distortion to measured harmonic emission under real world conditions. The conclusions which are drawn at the end of this paper are based on high precision harmonic current measurements, which have been carried out for a central inverter with a nominal power of 225 kVA. The harmonic emissions were measured for different types of grid configurations and background distortion.
WiFi Data Acquisition System and online monitoring applied to thermoelectric microgeneration modules
Authors: R. I. S. Pereira  , P. C. M. Carvalho  , S. C. S. Jucá
Published: April 2017

The present paper describes the development of an online monitoring and WiFi data acquisition system using free software applied to microgeneration based on thermoelectric modules. Monitoring and data acquisition systems are applicable in various stages of the microgeneration process, e.g., in the energy resource evaluation, generation failures prognosis, practical verification of project data and efficiency of generation. The online monitoring and data acquisition system was developed using a WiFi modem coupled to a microcontrolled board based on free software. This monitoring system was applied to thermoelectric modules and was also developed a wireless communication with the online server which sends microgeneration values to the data bank. The free software for online monitoring and WiFi data acquisition allows the analysis of stored data and charts through mobile devices as notebooks, tablets and smartphones. Moreover, the system can also be expanded to record values from analogical or digital sensors used in plants based on other renewable energy sources.
A criterion for rotational augmentation based on a boundary-layer analysis
Authors: W.-G. Früh  , A.C.W. Creech
Published: April 2017

Rotational augmentation is a well-known phenomenon of rotating aerofoils on wind turbines and helicopters where the lift or torque is improved compared to that of stationary aerofoils. We present an analysis which is based on the concept of a developing boundary layer and the Ekman boundary layer using a 3D Finite-Element Analysis of the developing laminar boundary layer over a flat plate in a rotating frame of reference. A parametric analysis addresses the Reynolds number, the Ekman number and the speed ratio in turn. The results demonstrate that the surface's rotation limits the boundary layer to the thinner of the two boundary layers, and that it induces a span-wise flow in the radial direction which in turn leads to Ekman suction. This Ekman suction provides a mechanism to counteract an adverse pressure gradient and thus prevent stall. The criterion derived from this was successfully applied and tested against observations and full CFD results.
Chair Fans as Energy Efficient Strategy to Aid Localized Ventilation
Authors: Carine Habchi  , Kamel Ghali  , Nesreen Ghaddar
Published: April 2017

Nowadays, the air conditioning industry is deviating from the conventional mixing ventilation technique towards localized ventilation. Displacement ventilation and ceiling personalized ventilation are localized systems presenting a high potential in insuring good indoor air quality while reducing the energy consumption compared to mixing ventilation. In this work it is proposed to enhance their performance by assisting them with chair fans controlling the behavior of occupants’ convective plumes. Computational fluid dynamics models were developed to simulate office spaces ventilated by displacement ventilation and ceiling personalized ventilation equipped with chair fans. The Lagrangian technique was adopted to track particle trajectories to determine particle behavior after generation from occupant respiratory activity. A parametric study was conducted to assess the effect of chair fan flow rate on each system performance in terms of indoor air quality. Recommendations were given to reduce cross-infection between occupants for both types of localized systems studied with reduced energy consumption. The total chair fans flow rate was optimized for both cases to insure acceptable indoor air quality resulting in significant energy savings. It was found that the optimal total chair fans flow rate per occupant was approximately 14 L/s when assisting displacement ventilation while it was 10 L/s when aiding ceiling personalized ventilation.
Suggestion of a design method for horizontal spiral coil type ground heat exchangers
Authors: Min-Jun Kim  , Seung-Rae Lee  , Seok Yoon  , Jun-Seo Jeon  , Min-Seop Kim
Published: April 2017

The need of geothermal energy is constantly increasing for economical and environmental benefits. Horizontal ground heat exchangers (GHEs) can reduce the installation cost and they can also compromise between increasing in efficiency and costs. There are many kinds of GHEs, and it is known that slinky and spiral coil type GHEs show high thermal performance in the horizontal system. However, there is no adequate guideline to design the spiral coil type GHEs even though there is a design program for the slinky type GHEs. Therefore, this paper presents a design module for the horizontal spiral coil type GHEs. Dried Joomunjin standard sand was filled in a steel box including a horizontal spiral coil type GHE of which the size was 5m x 1m x 1m and thermal response tests (TRTs) were conducted for 30 hours to evaluate heat exchange rates. Based on the experimental results, a modified design module, that includes a scheme to properly evaluate design parameters such as ground thermal resistance and borehole thermal resistance used in the Kavanaugh theory for designing a spiral coil type GHE, was suggested.
A comparison of different methodologies for rating definition in overhead lines
Authors: R. Martínez  , A. Arroyo  , M. Mañana  , P. Bernardo  , R. Mínguez  , R. Garrote
Published: April 2017

The grid integration of renewable energy supposes an important problem to deal with for Distributor System Operators (DSO). Distributor and transmission system operators have been using static rates for a long time to manage electric systems. Currently operators deal with one, annual, static rate or four, seasonal, static rates. This paper is devoted to the analysis of a real case of ampacity management in a 132 kV overhead line for the purpose of stablishing new static rates based on different temporal intervals.
Impact of a High Penetration of Electric Vehicles and Photovoltaic Inverters on Power Quality inan Urban Residential Grid PartII-Harmonic Distortion
Authors: S. Müller  , J. Meyer  , M. Naumann  , F. Möller  , M. Radauer
Published: April 2017

This paper presents a measurement-based assessment of the impact of a high penetration of plug-in electric vehicles with on-board charger (EVC) and photovoltaic inverters (PVI) on Power Quality in a public low voltage (LV) network with residential customers. This is the second part of a two-part paper.While part I provides all details about the measurement location and discusses the impact on unbalance, this part is focused on the harmonic distortion. The results are based on extensivemeasurements in an urban grid with almost 100 households(HH),43 PVIs and 36 EVCs. This paper discusses in detail the impact of PVI and EVC on selected low order harmonics as well as the total harmonic distortion at different levels of customer aggregation. At first the individual impact of a single PVI and EVC are analyzed for different operating conditions. In particular, a sunny day, a cloudy day and hours during the night are used for PVI,while periods of charging and periods of no-charging are considered for EVC. Next, the interaction between PVI, EVCand the residual household load at household level is discussed. Finally, the impact on current and voltage distortion at the level of the low voltage grid is analyzed.
Proposal of an applicable ZVT Quadratic Boost Converter Topology in Renewable Energies.
Authors: Mikael N. Oliveira  , Diego F. Rodrigues  , Lúcio R. Barbosa
Published: April 2017

In this paper, a new active snubber cell is proposed to contrive a new quadratic Boost pulse width modulated (PWM) converter. This snubber cell provides zero voltage transition (ZVT) for the main switch of a converter. A New ZVT–PWM Quadratic Boost converter equipped with the proposed snubber cell provides most the desirable features of ZVT converters presented previously, and overcomes most the drawbacks of these converters providing a large voltage step-up. Subsequently, the new converter can operate with soft switching successfully at very wide line and load ranges and at considerably high frequencies. Moreover, the main devices do not have any additional voltage and current stresses. In this study, a detailed analysis of the new converter is presented, and this theoretical analysis is verified exactly by simulation and a prototype converter.
Operation Strategy for Hydrogen Production by Water Electrolysis Powered by Solar Photovoltaic Energy
Authors: E. Amores  , J. Rodríguez  , J. Oviedo
Published: April 2017

Combination of alkaline water electrolysis with renewable energy sources can be one of the most sustainable strategies for H2 production. However, solar and wind energy sources are strongly dependent on weather conditions, which can cause fluctuations of power supplied to the electrolyzer. This variability usually involves some problems related with increments of the void fraction, generation of explosive mixtures or reduction in the efficiency. In order to limit these effects and to reduce the required voltage in the electrolysis, an optimized operation strategy is proposed in this study based on pumping flow according to the current supplied to the electrolysis cell. To this aim, a mathematical model including influence of different operation variables as electrodes distance, temperature and electrolyte flow rate has been developed and used as optimization tool. The obtained results confirm the convenience of the selected strategy, especially when the electrolyzer is powered by RREE.