Perspectivas y aplicaciones reales del grafeno después de 16 años de su descubrimiento / Perspectives and real applications of graphene at 16 years after its breakthrough / Perspectivas e aplicações reais do grafeno após 16 anos de sua descoberta

Resumen A 16 años del gran descubrimiento del grafeno los focos de atención vuelven a estar en este material con el reporte de su comportamiento superconductor dependiendo del apilado de sus capas. Sin embargo, su nombre durante estos últimos años no solo se ha relacionado a la superconductividad, sino que ha sido relacionado con una diversidad muy amplia de aplicaciones, en disciplinas muy diversas, entre las que cabe mencionar: materiales opto-electrónicos, electrodos para catálisis, dispositivos para tratamiento de desechos, biosensores, entre otros. Esto ha hecho que un gran número de grupos de investigación se hayan interesado no solo en estudiar sus propiedades, sino también en investigar nuevos métodos sintéticos que puedan ser escalables a niveles industriales, sin perder sus propiedades electrónicas y mecánicas. A pesar de los numerosos estudios y los recursos invertidos en grafeno no todas las aplicaciones han llegado a ser una realidad, en esta revisión se muestran algunas de las más exitosas.

Abstract 16 years after the great discovery of graphene, the focus and attention are again on this material after the report of its superconducting behavior depending on the stacking of its layers. The graphene has not only been related to superconductivity but has also been related to a wide diversity of applications, in very diverse disciplines. Among them, we can mention: Opto-electronic materials, electrodes for catalysis, devices for waste-water treatment, biosensors, batteries, and solar cells. This has caused a large number of research groups to be interested not only in the study of its properties, but also in the research of new synthetic methods that can be scaled to industrial levels, without losing its electronic and mechanical properties. Despite numerous studies and resources invested in graphene, not all applications have become a reality, some of the most successful are shown in this review.

Resumo 16 anos após a grande descoberta do grafeno, o foco e as atenções voltam a ser neste material com o relato de seu comportamento supercondutor em função do empilhamento de suas camadas. No entanto, seu nome nos últimos anos não tem sido apenas relacionado à supercondutividade, mas tem sido relacionado a uma diversidade muito ampla de aplicações, em disciplinas muito diversas. Entre eles podemos citar: materiais optoeletrônicos, eletrodos para catálise, dispositivos para tratamento de águas residuais, biossensores, baterias e células solares. Isso fez com que um grande número de grupos de pesquisa se interessassem não apenas em estudar suas propriedades, mas muitas pesquisas também foram feitas na geração de métodos sintéticos que pudessem ser dimensionados para níveis industriais, sem perder suas propriedades eletrônicas e mecânicas. Apesar dos inúmeros estudos e recursos investidos em grafeno, nem todas as aplicações se tornaram realidade, algumas das mais bem-sucedidas são apresentadas nesta revisão.

Benefit Analysis of Grid Connected Photovoltaic Solar System with Energy Storage

Abstract The use of batteries combined with photovoltaic (PV) systems connected to the grid allows the storage of surplus energy from photovoltaic generation for later use. This combination can reduce dependence on the grid, since, for most consumers, peak consumption does not occur simultaneously with peak generation from the PV system. This article describes the initial operation of a PV system with 10.72kWp connected to grid and associated to a storage system with 57.6kWh lead-acid batteries installed at the Federal University of Technology - Paraná, in Curitiba city, Campus Neoville. We present an analysis of the benefits obtained from the combined use of the PV system connected to the grid with energy storage, reducing the total energy consumed from the grid. A brief analysis of the demand showed that, for this UTFPR campus, the peak power consumption occurred between 10:00 and 12:00 AM, which was also the interval of peak photovoltaic generation. We have observed that a scheduled battery discharge of 5.5% of the storage capacity from May to November and 9% discharge in December has resulted in R$ 1,154.44 of saving in the first seven months of operation.

Analytic Hierarchy Process Algorithm Applied to Battery Energy Storage System Selection for Grid Applications

Abstract The Brazilian Power Sector is preparing the introduction of battery energy storage in its distribution lines for energy quality control. The technical and financial viability of this new technology depends on several factors: battery technologies, geographical locations, environmental restrictions and the local regulation. One of the objectives of the present project was to create a methodology for helping technicians to choose the best battery technology for each particular application. The Analytic Hierarchy Process - AHP algorithm was selected to take into account all the above-mentioned factors. This methodology was applied to a case study considering four different commercially available battery energy storage systems (BESS) and the methodology was able to recommend the best choice by taking into account all the criteria and subcriteria considered. The second objective of the present project is to evaluate a real hybrid BESS operation composed of two different battery technologies. Up to the moment when this paper was submitted the BESS has not been installed yet. The installation place has already been selected, a feeder-line with 1,360 kW peak power, and monitored for energy quality. The BESS has been sized, a 250 kW/1 MWh flow battery together with a 250 kW/500 kWh lithium-ion battery and the purchase process has been initiated. Both battery technologies will work in separate and joint operations for power quality in on-grid and island cases.

State of the Art of the Application of Energy Storage Systems in Photovoltaic Buildings

Abstract Photovoltaic (PV) buildings are increasingly present in urban centers and can generate their own energy becoming independent of the grid, depending on their consumption profile. However, most residential and commercial consumers show their peak demand at night, when there is no photovoltaic generation, needing the electricity grid to meet the demand of these facilities. Peak demand lead to increased costs for these consumers and end up disrupting the power quality of the grid. One possible solution for these listed problems is by applying storage systems to these buildings, which is already being done in some countries and can increase the PV generation. Aiming to seek the state of the art of these systems, this article brings a review of the literature, highlighting the possible modes of operation and a real case of application in PV buildings in the world. Also are described the storage technologies most appropriate for applications in these buildings, highlighting their advantages and disadvantages. It is expected to gain greater knowledge of these systems, in order to overcome the challenges of intermittence generated by renewable sources, enabling the reduction of energy demand costs in these customers so that it can also be applied in the Brazilian scenario.

Demand Manager for Energy Consumer with Local Storage and Microgeneration

Abstract The current reality of the energy market requires generation, control, distribution and consumption to become more efficient. Recent arrangements with electric energy stored in accumulators appear as strategic tools in the environment where the cost of energy supplied by the concessionaires and permission holders has accumulated successive increases, indirectly enabling the control and management of applications of micro or local minigeneration, from renewable sources in general. Systems with energy storage (e.g. batteries) and local demand management (many consumer units) achieve great efficiency by allowing the optimized consumption of the available energy, both by the local power grid and by the accumulated grid. Other advantages are presented for the distributors, allowing the relief of the electricity network, remunerating the investment in reduced intervals of time. Consideration should be given to the possibility of local autonomy, even if partially, by providing energy from the storage to the local loads in eventual failures in the supply of energy by the distribution network or at times where supply has a higher cost.

Fabricación de nanofibras de TiO2/ZnO para aplicaciones de almacenamiento de energía / Fabrication of TiO2/ZnO nanofibers for energy storage applications / Fabricação de nanofibras TiO2/ZnO para aplicações de armazenamento de energia

Resumen Se estudiaron nanofibras de TiO2/ZnO preparadas por calcinación de fibras precursoras de poli (vinil acetato), isopropóxido de titanio y nano polvo de zinc elaboradas por la técnica de electrohilado. La estructura y la morfología de las nanofibras de TiO2/ZnO y fibras precursoras se caracterizaron por Microscopia Electrónica de Barrido (SEM), Microscopia Electrónica de Barrido de Emisión de Campo equipado con Espectroscopia Dispersiva de Rayos X (FESEM-EDS), Espectroscopia de Infrarrojo con Transformada de Fourier (FTIR) y Difracción de Rayos X (XRD). El análisis XRD mostró la estructura cristalina de los óxidos de titanio (anatasa) y de zinc (wurzita hexagonal), después de calcinar las fibras precursoras a 500°C. Las microfotografías de SEM muestran que tanto las fibras precursoras como las nanofibras forman redes uniformes y buena morfología. Estas nanofibras de dióxido de titanio /óxido de zinc presentan buen área de superficie y diámetros de 200 nm apropiados que podrían ser de aplicación potencial en el campo de energía renovable, en particular, para la fabricación de celdas solares.

Abstract The TiO2 /ZnO nanofibers prepared by the calcination of polyvinyl acetate of precursor fibers, titanium isopropoxide and nano zinc powder produced by the electrospinning technique were studied. The structu-re and morphology of TiO2 /ZnO nanofibers and precursor fibers were characterized by Scanning Electron Microscopy (SEM), Field Emission Scanning Electron Microscopy coupled to Energy Dispersive X-ray spectroscopy (FESEM-EDS), Fourier Transform Infrared Spectroscopy (FTIR) and XRD (X Ray Diffraction). XRD analysis displayed crystalline structures of titanium oxides (anatase) and zinc (hexagonal wurzite), after calcining the precursor fibers at 500 °C. SEM microphotographs display that both precursor fibers and nanofibers form uniform networks and good morphology. These titanium dioxide / zinc oxide nanofibers get good surface area and appropriate 200 nm diameters which could potentially be applied in the renewable energy field, particularly for solar cells manufacturing.

Resumo Nanofibras de TiO2 /ZnO preparado por calcinação de fibras precursoras de poli (acetato de vinila), isopropóxido de titânio e pó nano de zinco produzidos por eletrofiação técnica estudada. A estrutura e morfologia das nanofibras de TiO2/ ZnO e fibras precursores foram caracterizados por microscopia eletrônica de varredura (SEM), Microscopia eletrônica de varredura de emissão de campo equipada com espectroscopia de raios-X dispersiva (FESEM-EDS), Espectroscopia de Fourier Transform Infrared (FTIR) e difração de raios X (DRX). A análise de XRD mostrou a formação de estruturas de cristal de óxido de titânio (anatase) e zinco (wurtzita hexagonal), depois de fibras precursoras de calcinação a 500 °C. Micrografias mostram que tanto o precursor e fibras nanofibras uniformes formar redes e boa morfologia. Estas nanofibras de dióxido de titanio /óxido de zinco apresentam bom área de superfície e diâmetros de 200 nm apropriados que poderiam ser de aplicativo potencial no campo de energia renovável, em particular, para a fabricação de celas solares.

Condición fisiológica de una población de Arca zebra (Bivalvia: Arcidae) del banco de Chacopata, Sucre, Venezuela / Physiological condition of an Arca zebra (Bivalvia: Arcidae) population from Chacopata, Sucre, Venezuela

ResumenLos índices de condición en sus diferentes versiones reflejan el desempeño del organismo en su ambiente, así como la condición somática, el valor nutritivo, la importancia comercial, el papel ecológico, y periodos de engorde. En este estudio se evaluaron diferentes índices fisiológicos, con la finalidad de conocer el estado de la población de Arca zebra y proponer estrategias de explotación y conservación con fines de consumo del recurso. Se recolectaron un total de 240 ejemplares entre julio 2010-julio 2011, en el banco de Chacopata. Mensualmente se midió la longitud total, altura y grosor de la concha. Los tejidos blandos fueron deshidratados para obtener la masa seca total. Se analizaron diferentes índices de condición: los basados en la masa del organismo, los que combinan masa y longitud de la concha, índice gonadal, índice muscular, rendimiento de la carne, la masa fresca de los tejidos blandos en relación a la longitud total y la masa seca de los tejidos blandos en relación a la longitud total. El modelo de crecimiento fue alométrico positivo entre la longitud-masa seca total. El peso de la gónada ejerció una marcada influencia sobre el índice de condición, índice gonadosmático y rendimiento.La población estuvo conformada por 82 machos y 158 hembras. Los incrementos de la masa de los tejidos blandos fueron proporcionales a las dimensiones de la concha. Se propone el índice que contrasta la masa fresca de los tejidos blandos en relación a la longitud total, como una herramienta que le permitiría a los pescadores a estimar la dinámica de la población de A. zebra, la cual ayudaría a ejercer una pesquería sustentable en el tiempo, mientras se mantengan los cánones de extracción.

Abstract:Condition indices reflect the performance of an organism in their environment, as well as their somatic condition, nutritional value, commercial importance, the ecological role and fattening periods. In this study, different physiological indices were evaluated in order to know the Arca zebra population status, and to suggest operation and sustainability strategies for this resource use and consumption. A total of 240 samples (82 males and 158 females) were collected between July 2010 and July 2011, from the Chacopata bank site. Bivalve biometric measurements were made monthly and considered: total shell length, height and width; besides, soft tissues were dehydrated to obtain total dry mass. Different condition indices were analyzed based on the body mass, or on the combination of mass and shell length: gonadal index, muscle index, meat yield, the fresh mass of soft tissue in relation to the total length, and dry mass of soft tissue relative to the total length. We found the model with positive allometric growth between the length-total dry mass. The gonadal weight exerted a marked influence on the condition index, gonadosomatic index and meat yield. Increases in soft tissue mass were proportional to the dimensions of the shell. The index contrasts fresh mass of soft tissue in relation to the total length, as a tool that would allow fishers to estimate the population dynamics of A. zebra, and to practice a sustainable fishery over time, while keeping the extraction canons. Rev. Biol. Trop. 64 (3): 1345-1352. Epub 2016 September 01.

Relationship between Energy Storage and Clinical Practicability of Prosthetic Feet YANG Wen-bing / 中国康复理论与实践

@#Objective To investigate the relationship between energy storage and clinical practicability of prosthetic feet.Methods Six different prosthetic feet were selected and tested the ratio between released energy and absorbed energy of these feet through a specially-designed equipment. Then, the differences on total cycles of heartbeat of the amputee were tested when he wore the six feet separately to walk and run.Results The total cycles of heartbeat of the amputee with feet of higher energy storage were apparently lower during running, but might be equal or even a little higher during walking.Conclusion The ability of energy-saving of a foot is more important than the ability of energy-storing.