Analysis of the efficiency of wind turbine gearboxes using the temperature variable

The aim of this paper is to evaluate how lubricant selection affects gearbox efficiency and overall energy production by analysing real data from wind farms, monitored and controlled by a Supervisory Control and Data Acquisition (SCADA system). The turbines analysed worked with two or more oil types for the same amount of hours, which allowed to establish relations between the active power curves and wind velocity; oil temperature inside gearboxes and wind velocity; and oil temperature inside gearboxes and active power production. The results of this study evidenced a direct relation between oil characteristics and energy efficiency i.e. gearboxes working with mineral oil perform better then gearboxes working with synthetic oils. Those differences can be significant in terms of active power production. Also, it was observed oil degradation as function of temperature increase, with changes on viscosity, which reveals that temperature behaviour along the active power curve is strongly related to oil' characteristics. (C) 2018 Elsevier Ltd. All rights reserved.Agência financiadora Portuguese Foundation for Science and Technology (FCT) PTDC/AAG-TEC/1710/2014 MONITOR project - Atlantic Area EAPA_333/2016 Portuguese Foundation for Science and Technology under the Portuguese Researchers' Programme 2014 IF/00286/2014/CP1234 Marie Sklodowska-Curie Actions of the European Union's H2020-MSCA-IF-EF-RI-2016/under REA - 748747info:eu-repo/semantics/publishedVersionhttp://creativecommons.org/licenses/by/4.0

Marine energy prototype testing at Ria Formosa

Economic growth and increasing human demands are among the most important factors for growing world energy consumption. Energy is present in everything around us: it is a property of all objects and is essential to life. We find various forms of energy in the world around us. When plants grow, for example, they are converting sunlight energy into chemical energy in the form of carbohydrates and other compounds stored in your body (e.g. sugars). The form of energy that man uses most today is the chemical energy contained in fossil fuels, such as oil, coal and natural gas. About 80% of the energy we use comes from these sources. However, these sources are very polluting, since their use releases substances harmful to the environment and to public health. An example of this is the increased concentration of greenhouse gases such as carbon dioxide (CO2) in the atmosphere, which is a cause of climate change. In addition to pollutants, these sources of energy are non-renewable, which means that they are being consumed at a faster rate than is necessary for their production, so their availability is decreasing. Due to the increasing oil and natural gas prices, reduced fuel reserves and the requirement for reduced CO2 emissions to avert climate change, the use of alternative energy sources is both financially unavoidable and environmentally preferable (UN, 2015). Hence, generating renewable energy is nowadays one of the most relevant endeavours for research. Countries worldwide now recognise the need to incorporate renewable energy resources in their energy policy as an alternative to finite fossil fuel resources in order to achieve future energy security and to mitigate the effects of climate change induced by human activities. Today, renewable energy is now firmly entrenched as the world's fastest growing energy sector (IEA, 2017).info:eu-repo/semantics/publishedVersio

Gestión de Recursos Humanos : La planeación para el proceso de reclutamiento y selección de personal de la Empresa

Para elaborar el presente trabajo enfocado en la administración de recursos humanos , se estructuro el protocolo en cinco capítulos, así como sus respectivas conclusiones, anexos y bibliografías, las cuales se fueron agrupando con el fin de dar un orden lógico a la estructura del trabajo. El primer capítulo nos permite conocer acerca de la historia de la administración de recursos humanos, conceptos y aspectos fundamentales que inciden en el desarrollo del capital humano, como también de la empresa. El segundo capítulo contiene las técnicas, el proceso, ventajas y desventajas del reclutamiento de las organizaciones, así como los medios que hoy día se están llevando a la practica en las compañías, para contar con el recurso calificado que responda a toda las necesidades de la misma. El tercer capítulo hace referencia a la selección del talento humano utilizando técnicas adecuadas para obtener personas idóneas que logren sus metas organizacionales, a cualquier plazo proyectado. El cuarto capítulo explica las formas de evaluar el desempeño y los métodos tradicionales que utilizan en las empresas para conocer el grado de efectividad en las organizaciones. En el quinto y último capítulo se hace un estudio sobre la compañía INISER para dar a conocer las técnicas y medios que tiene la institución para reclutar y seleccionar su personal

Assessing the effects of Tidal Energy Converter array size on hydrodynamics of Ria Formosa (Portugal)

info:eu-repo/semantics/publishedVersio

An evaluation of offshore wind power production by floatable systems: a case study from SW Portugal

The challenge for floating offshore wind structures is to reduce costs. The industry needs a wind turbine support solution that can be fabricated and deployed from existing shipyards and port facilities, while investors need accurate estimations and forecasts of wind resources and quantified information on the inherent variability in wind power generation. This paper merges hindcast model data with observed in situ data to characterize the wind resource potential off the SW coast of Portugal. The validation procedure adopted allows an estimation of the coefficient used for power-law extrapolation of the wind measurements and a reduction in the uncertainty of the power density calculations. Different types of turbine model are compared and site metocean characteristics are examined as a basis for choosing between existing wind floatable solutions. The calculations using four different wind turbine models indicate a preferable installed capacity of 3-4 MW for a hub height of 90-120 m (i.e., representing the best capacity factor and load hours). There is a consistent difference in power density of about 20% from a location 5 nautical miles (NM) offshore to one 10 NM offshore, which represents an increment of 20% -25% in energy production depending on the particular wind turbine capacity factor. (C) 2017 Elsevier Ltd. All rights reserved.Portuguese Foundation for Science and Technology [FCT - PTDC/AAG-TEC/1710/2014]Portuguese Foundation for Science and Technology under the Portuguese Researchers' Programme [IF/00286/2014/CP1234]Portuguese Foundation for Science and Technology Investigator Programme [IF/01142/2015

Estimating the optimum size of a tidal array at a multi-inlet system considering environmental and performance constraints

This paper investigates the optimum tidal energy converter array density at a tidal inlet by applying surrogate-based optimisation. The SBO procedure comprises problem formulation, design of experiments, numerical simulations, surrogate model construction and constrained optimisation. This study presents an example for the Faro-Olhão Inlet in the Ria Formosa (Portugal), a potential site for tidal in-stream energy extraction. A 35 kW Evopod™ floating tidal energy converter from Oceanflow Energy Ltd. has been used for array size calculations considering two design variables: (1) number of array rows, and (2) number of tidal energy converter per row. Arrays up to 13 rows with 6–11 tidal energy converters each are studied to assess their impacts on array performance, inlets discharges and bathymetry changes. The analysis identified the positive/negative feedbacks between the two design variables in real case complex flow fields under variable bathymetry and channel morphology. The non-uniformity of tidal currents along the array region causes the variability of the resource in each row, as well as makes it difficult to predict the resultant array configuration interactions. Four different multi-objective optimisation models are formulated subject to a set of performance and environmental constraints. Results from the optimisation models imply that the largest array size that meets the environmental constraints is made of 5 rows with 6 tidal energy converter each and an overall capacity factor of 11.6% resulting in an energy production of 1.01 GWh year−1. On the other hand, a higher energy production (1.20 GWh year−1) is achieved by an optimum array configuration, made of 3 rows with 10 tidal energy converters per row, which maximises power output satisfying environmental and performance restrictions. This optimal configuration permits a good level of energy extraction while having a reduced effect on the hydrodynamic functioning of the multi-inlet system. These results prove the suitability and the potential wide use of the surrogate-based optimisation method to define array characteristics that enhance power production and at the same time respect the environmental surrounding conditions.info:eu-repo/semantics/publishedVersio

Plan estratégico para la clínica Medintegral., S.A. El Redentor orientado a mejorar la atención al paciente asignado

Plantea propuestas que contribuyan a dar solución al problema principal de la Clínica Medintegra El Redentor. Para ello se realizó un diagnostico Institucional por medio de la Metodología FODA el cual es un proceso de generación de información que permite conocer las variables internas y externas para determinar tanto los puntos fuertes y débiles de la clínica así como sus oportunidades y amenazas

Análisis del uso de Instagram como herramienta alternativa en el ejercicio periodístico en los estudiantes de 4to y 5to año de la carrera de Comunicación para el Desarrollo de la UNAN-Managua durante el II semestre del año 2020

La humanidad está viviendo una época de transición hacia una era más digitalizada que ha impactado en la forma de vida de las personas, ha habido cambios sociales, económicos y una nueva forma de vida y la manera de comunicarse tradicional ha dado un giro hacia lo digital, las redes sociales han permitido contactos múltiples y una intensa interactividad, las personas están conectadas constantemente a través de los aparatos tecnológicos y es por esto que las llamadas redes sociales se han convertido en soportes de información, son la oportunidad de los medios de comunicación de llegar a miles de millones de personas. Informar a través de las redes sociales se ha convertido también en un medio alternativo para el periodista independiente y le ha otorgado herramientas más fáciles de manejar para transmitir noticias. En la actualidad las redes sociales facilitan las comunicaciones a distancia, lo que antes esto generaba gastos casi imposibles de solventar. La era digital ha venido a revolucionar la forma de comunicarnos, brindando muchas ventajas para ejercer periodismo independiente desde diferentes plataformas digitales y con mayor número de receptores o personas alcanzadas. El presente trabajo se desarrolla sobre el análisis del uso de Instagram en el ejercicio periodístico en los estudiantes de cuarto y quinto año de la carrera de comunicación para el desarrollo durante el segundo semestre del año 2020, el principal objetivo de la investigación es analizar cuáles son los usos de Instagram que hacen los estudiantes como herramienta para ejercer periodismo. Actualmente Instagram es una red social masiva que tiene millones de usuarios y que cuenta con herramientas de interacción con audiencias, esta red permite gestionar y hacer llegar la información al público. Para la realización de esta investigación se escudriño en trabajos investigativos sobre el tema de Instagram como plataforma alternativa para el periodista digital y el ejercicio periodístico y relacionarlos con los usos que hacen en este caso los estudiantes de Comunicación para el Desarrollo de dicha red socia

The effectiveness of nano chemotherapeutic particles combined with mifepristone depends on the PR isoform ratio in preclinical models of breast cancer

There is clinical and experimental evidence suggesting that antiprogestins might be used for the treatment of selected breast cancer patients. Our aim was to evaluate the effect of albumin-bound paclitaxel (Nab-paclitaxel) and pegylated doxorubicin liposomes (PEG-LD) in combination with mifepristone (MFP) in experimental breast cancer models expressing different ratios of progesterone receptor (PR) isoforms A and B. We used two antiprogestin-responsive (PRA>PRB) and two resistant (PRA<PRB) murine mammary carcinomas growing in BALB/c, GFP-BALB/c or nude mice, along with human T47D-YA and T47D-YB xenografts growing in immunocompromised NSG mice. MFP improved the therapeutic effects of suboptimal doses of Nab-paclitaxel or PEG-LD in murine and human carcinomas with higher levels of PRA than PRB. MFP induced tissue remodeling in PRA-overexpressing tumors, increasing the stromal/tumor cell ratio and the number of functional vessels. Accordingly, an increase in nanoparticles and drug accumulation was observed in stromal and tumor cells in MFP-treated tumors. We conclude that MFP induces an increase in vessels during tissue remodeling, favoring the selective accumulation of nanoparticles inside the tumors. We propose that antiprogestins have the potential to enhance the efficacy of chemotherapy in breast tumors with a high PRA/PRB ratio.Fil: Sequeira, Gonzalo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Vanzulli, Silvia I.. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Rojas, Paola Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Lamb, Caroline Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Colombo, Lucas Luis. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncologi­a "angel H. Roffo"; ArgentinaFil: May, Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Molinolo, Alfredo. National Institutes of Health. National Institute of Dental and Craniofacial Research. Oral and Phayngeal Cancer Branch; Estados UnidosFil: Lanari, Claudia Lee Malvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentin

Action of Hexachlorobenzene on tumor growth and metastasis in different experimental models

Hexachlorobenzene (HCB) is a widespread organochlorine pesticide, considered a possible human carcinogen. It is a dioxin-like compound and a weak ligand of the aryl hydrocarbon receptor (AhR). We have found that HCB activates c-Src/HER1/STAT5b and HER1/ERK1/2 signaling pathways and cell migration, in an AhR-dependent manner in MDA-MB-231 breast cancer cells. The aim of this study was to investigate in vitro the effect of HCB (0.005, 0.05, 0.5, 5μM) on cell invasion and metalloproteases (MMPs) 2 and 9 activation in MDA-MB-231 cells. Furthermore, we examined in vivo the effect of HCB (0.3, 3, 30mg/kg b.w.) on tumor growth, MMP2 and MMP9 expression, and metastasis using MDA-MB-231 xenografts and two syngeneic mouse breast cancer models (spontaneous metastasis using C4-HI and lung experimental metastasis using LM3). Our results show that HCB (5μM) enhances MMP2 expression, as well as cell invasion, through AhR, c-Src/HER1 pathway and MMPs. Moreover, HCB increases MMP9 expression, secretion and activity through a HER1 and AhR-dependent mechanism, in MDA-MB-231 cells. HCB (0.3 and 3mg/kg b.w.) enhances subcutaneous tumor growth in MDA-MB-231 and C4-HI in vivo models. In vivo, using MDA-MB-231 model, the pesticide (0.3, 3 and 30mg/kg b.w.) activated c-Src, HER1, STAT5b, and ERK1/2 signaling pathways and increased MMP2 and MMP9 protein levels. Furthermore, we observed that HCB stimulated lung metastasis regardless the tumor hormone-receptor status. Our findings suggest that HCB may be a risk factor for human breast cancer progression.Fil: Pontillo, Carolina Andrea. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; Argentina;Fil: Rojas, Paola Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina;Fil: Chiappini, Florencia Ana. Consejo Nacional de Investigaciones Científicas y Técnicas . Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos; Argentina; Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; Argentina;Fil: Sequeira, Gonzalo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina;Fil: Cocca, Claudia Marcela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Físico Matemática; Argentina;Fil: Crocci, Máximo. Instituto de Inmunooncología Crescenti; Argentina;Fil: Colombo, Lucas Luis. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología; Argentina;Fil: Lanari, Claudia Lee Malvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina;Fil: Kleiman de Pisarev, Diana. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; Argentina;Fil: Randi, Andrea Silvana. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; Argentina