165 research outputs found

    Hacia el riego de precisión en el cultivo de fresa en el entorno de Doñana

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    España es el principal productor de fresa (Fragaria x ananassa) fresca de Europa, con una producción cercana a las 300.000 t/año. Esta producción se concentra en la provincia de Huelva, destinándose el 95% de la misma a mercados internacionales cada vez más exigentes con las condiciones y técnicas de producción, que deben ir orientadas a un uso eficiente de los recursos empleados y a minimizar el impacto ambiental derivado de dicha actividad. El cultivo intensivo de fresa, que se desarrolla en macrotúneles de plástico sobre lomos acolchados, demanda volúmenes importantes de agua para satisfacer las necesidades hídricas del cultivo así como para labores de preparación del suelo o alomado y riego de apoyo en la fase de plantación. El carácter intensivo del cultivo ha suscitado críticas medioambientales en torno al uso del agua y la gestión que se realiza de ésta, que se han acentuado en parte por la cercanía de la zona productora al Parque Nacional de Doñana, y por otra parte a la compleja Normativa en materia de regadío existente en la zona. Para poder hacer frente, de forma racional, a las fuertes críticas de que es objeto el sector de la fresa onubense, es necesario realizar un análisis profundo sobre la demanda real de agua de riego del cultivo, así como de la gestión que se realiza de dicho recurso por los agricultores. Dicho análisis permitirá identificar las buenas prácticas agrícolas especialmente en la gestión del riego e identificar las necesidades de mejora, para poder fomentar el uso sostenible del agua en una superficie cultivada que oscila entre las 6000-7000 ha, dependiendo de la campaña. En el capítulo 3 del presente trabajo se ha caracterizado la demanda de riego en un conjunto de 22 fincas comerciales de fresa en la zona de estudio, durante las tres campañas transcurridas entre 2010 y 2013. Se han estimado las necesidades de riego del cultivo para las condiciones de manejo típicas de la zona. Estas necesidades contemplan tanto el periodo productivo que requiere como término medio una dotación bruta de 5739 m3/ha, como las fases previas de preparación del suelo y plantación, que requiere por término medio 1300 m3/ha. Esto da lugar a unas necesidades totales de riego medias en torno a los 7000 m3/ha, que puede variar según el tipo de suelo y las condiciones climáticas y de cultivo de cada año. Los valores estimados se han contrastado con los...Spain has the largest concentration of strawberry (Fragaria x ananassa) producers in Europe. The annual yield, close to 300000 t is concentrated in Huelva province in the South west and is mainly devoted to the international markets (more than 95%) which demands high quality strawberries produced under sustainable conditions aimed to an efficient use of the resources used and to prevent the environmental impact derived from this activity. The intensive cultivation of strawberry, carried out on beds covered by black plastic inside polytunnels, demands large amounts of freshwater to satisfy the crop water requirements as well as other agronomic practices such as soil preparation and during plantation. In spite of the fact that strawberry farming generates wealth in the region, it is identified as a water intensive activity due to its high dependency on water resources. Therefore there is a concern regarding the environmental sustainability of the crop production in the area, mainly related to water abstraction. This concern is further aggravated by the circumstance that the production area is located in the vicinity of the Doñana National Park, which is a high environmentally sensitive area, as well as the complex irrigation regulation that there exists. Facing the smear campaigns being carried out against the strawberry sector in Huelva, in a rational way, requires developing a deep analysis about the current crop water demand, as well as the management that has been carried out by farmers. This analysis will allow identifying the good agricultural practices, mainly in irrigation management and the need´s for improvement in the process with the aim to promoting a sustainable use of water in the cropped area, that vary from 6000 to 7000 ha. In chapter 3, irrigation water has been analysed in a set of 22 farms during the seasons from 2010 to 2013. Crop water requirements for the particular conditions of the crop in the study area have been calculated. These requirements include the theoretical water needs that amount to an average value of 5739 m3/ha, and the volume of water for soil preparation and plantation that 1300 m3/ha require on average. The total volume of water required is around 7000 m3/ha, depending on the soil texture, and the weather and crop conditions during the season. Crop water needs values calculated have been compared with the real crop water demand recorded at farm scale in every farm that comprise the sample. The average total volume of water applied comes to 7066 m3/ha,..

    Energy Recovery Potential in Industrial and Municipal Wastewater Networks Using Micro-Hydropower in Spain

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    The use of micro-hydropower (MHP) for energy recovery in water distribution networks is becoming increasingly widespread. The incorporation of this technology, which offers low-cost solutions, allows for the reduction of greenhouse gas emissions linked to energy consumption. In this work, the MHP energy recovery potential in Spain from all available wastewater discharges, both municipal and private industrial, was assessed, based on discharge licenses. From a total of 16,778 licenses, less than 1% of the sites presented an MHP potential higher than 2 kW, with a total power potential between 3.31 and 3.54 MW. This total was distributed between industry, fish farms and municipal wastewater treatment plants following the proportion 51–54%, 14–13% and 35–33%, respectively. The total energy production estimated reached 29 GWh∙year−1, from which 80% corresponded to sites with power potential over 15 kW. Energy-related industries, not included in previous investigations, amounted to 45% of the total energy potential for Spain, a finding which could greatly influence MHP potential estimates across the world. The estimated energy production represented a potential CO2 emission savings of around 11 thousand tonnes, with a corresponding reduction between M€ 2.11 and M€ 4.24 in the total energy consumption in the country

    Síndrome coronario agudo y enfermedad de Erdheim-Chester. Patogénesis e implicaciones terapéuticas

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    ResumenLa enfermedad de Erdheim-Chester es una histiocitosis celular diferente a la histiocitosis de Langerhans, de origen incierto. Se caracteriza por una implicación multi-orgánica debida a la infiltración de los histiocitos CD68+/CD1a-, en forma de xantogranulomas, que afectan principal y comúnmente a la metáfisis y diáfisis de huesos largos. El diagnóstico se realiza mediante biopsia, donde se revelan histiocitos CD68+/CD1a-, carencia de proteína S, y presencia de gránulos de Birbeck. Se ha subestimado la implicación cardiovascular. Reportamos un caso de un varón de 67 años con la enfermedad de Erdheim-Chester e infarto de miocardio agudo, debido a implicación coronaria, además de enfermedad ósea, vascular, pituitaria y retroperitoneal. Revisamos la literatura relevante y describimos el tratamiento clínico de estos pacientes.AbstractErdheim-Chester disease is a non-Langerhans cell histiocytosis of uncertain origin. It is characterized by multiorgan involvement due to infiltration of CD68+/CD1a- histiocytes, in the form of xantogranulomas, most commonly affecting the metaphysis and diaphysis of long bones. The diagnosis is made by biopsy showing CD68+/CD1ahistiocytes, lack of S protein and Birbeck granules. Cardiovascular involvement is underestimated. We report a case of a 67 year-old man with Erdheim-Chester disease and acute myocardial infarction due to coronary involvement, in addition to bone, vascular, pituitary and retroperitoneal disease. We review relevant literature and describe the clinical management of these patients

    Role of the Renin-Angiotensin System and Aldosterone on Cardiometabolic Syndrome

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    Aldosterone facilitates cardiovascular damage by increasing blood pressure and through different mechanisms that are independent of its effects on blood pressure. In this respect, recent evidence involves aldosterone in the pathogenesis of metabolic syndrome. Although this relationship is complex, there is some evidence suggesting that different factors may play an important role, such as insulin resistance, renin-angiotensin-aldosterone system, oxidative stress, sodium retention, increased sympathetic activity, levels of free fatty acids, or inflammatory cytokines and adipokines. In addition to the classical pathway by which aldosterone acts through the mineralocorticoid receptors leading to sodium retention, aldosterone also has other mechanisms that influence cardiovascular tissue remodelling. Finally, overweight and obesity promote the adrenal secretion of aldosterone, increasing the predisposition to type 2 diabetes mellitus. Further studies are needed to better establish therapeutic strategies that act on the blockade of mineralocorticoid receptor in the treatment and prevention of cardiovascular diseases related to the excess of aldosterone and the metabolic syndrome

    Open-Source Application for Water Supply System Management: Implementation in a Water Transmission System in Southern Spain

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    Sustainable water use has become a critical issue for the future of the planet in face of highly probable climate change. The drinking water supply sector has made significant progress over the last 20 years, although improvements in the management of urban hydraulic infrastructures are still required. The proposed system, Integrated Tool for Water Supply Systems Management (ITWSM), built on three interconnected modules (QGIS database, Epanet hydraulic model, and Google My Maps app), was developed on open-source software. The core of ITWSM allows analyzing the behavior of water supply systems under several operation/failure scenarios. It facilitates decision making supported by the mobile application ITWSM-app. Information flows easily through the different decision levels involved in the management process, keeping updated the georeferenced database after system changes. ITWSM has been implemented in a real public water supply company and applied to manage breakdown repairs in water transmission systems. The use of the proposed methodology reduces the average cost of failure repair by 13.6%, mainly due to the optimal planning of the resources involved

    Energy Saving Measures in Pressurized Irrigation Networks: A New Challenge for Power Generation

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    In Spain and other countries, open channel distribution networks have been replaced by on demand-pressurized networks to improve the water-use efficiency of the water distribution systems, but at the same time the energy requirements have dramatically risen. Under this scenario, methodologies to reduce the energy consumption are critical such as: irrigation network sectoring, critical hydrant detection, improving the efficiency of the pumping system and the irrigation system, or introducing solar energy for water supply. But once these measures are undertaken, the recovery of the energy inherent in excess pressure in the network should be investigated. Hydropower energy recovery in irrigation is still largely unexplored and requires further investigation and demonstration. All of these methodologies should be considered as useful tools for both, the reduction of energy consumption and the recovery of the excess energy in pressurized irrigation networks. To accomplish this, the REDAWN project (Reducing Energy Dependency in Atlantic Area Water Networks) aims to improve the energy efficiency of water networks through the installation of innovative micro-hydropower (MHP) technology. This technology will recover wasted energy in existing pipe networks across irrigation, public water supply, process industry, and waste-water network settings

    Pump-as-Turbine Selection Methodology for Energy Recovery in Irrigation Networks: Minimising the Payback Period

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    In pressurized irrigation networks, energy reaches around 40% of the total water costs. Pump-as-Turbines (PATs) are a cost-effective technology for energy recovery, although they can present low efficiencies when operating outside of the best efficiency point (BEP). Flow fluctuations are very important in on-demand irrigation networks. This makes flow prediction and the selection of the optimal PAT more complex. In this research, an advanced statistical methodology was developed, which predicts the monthly flow fluctuations and the duration of each flow value. This was used to estimate the monthly time for which a PAT would work under BEP conditions and the time for which it would work with lower efficiencies. In addition, the optimal PAT power for each Excess Pressure Point (EPP) studied was determined following the strategy of minimising the PAT investment payback period (PP). The methodology was tested in Sector VII of the right bank of the Bembézar River (BMD), in Southern Spain. Five potential sites for PAT installation were found. The results showed a potential energy recovery of 93.9 MWh and an annual energy index per irrigated surface area of 0.10 MWh year−1 ha−1. Renewable energy will become increasingly important in the agriculture sector, to reduce both water costs and the contribution to climate change. PATs represent an attractive technology that can help achieve such goals

    Sustainable Water-Energy Nexus towards Developing Countries’ Water Sector Efficiency

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    Water management and energy recovery can improve a system’s sustainability and efficiency in a cost-effective solution. This research assesses the renewable energy sources used in the water sector, as well as the related water sector performance indicators within Portuguese water management systems. A deep analysis of 432 water entities in Portugal, based on ERSAR data base, was conducted in order to identify factors to be improved regarding the system efficiency. On the other hand, the potential energy recovery developed in the REDAWN project was also used as a reference for the application of micro hydropower (MHP) solutions in the water sector. A water and energy nexus model was then developed to improve the systems efficiency and sustainability. A real case study in Africa, the Nampula water supply system, located in Mozambique, was selected as a promising potential for energy recovery. The application of a pump-as-turbine (PAT) allows the reduction in system costs and environmental impacts while increasing its efficiency. The proposed MHP has a capacity to generate ~23 MWh/year, providing significant savings. The developed economic analysis indicates the project is profitable, with an IRR ~40% depending on the energy selling price. This project can avoid the emission of more than 12 tCO2 to the atmosphere, and it can help to reduce the system’s real losses by more than 10,000 m3/year. Consequently, it creates a total economic benefit of 7604 EUR/year

    Using the new technologies in claudication patients: CReTe: Claudication patients and telematic register

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    Objetivo: Presentamos una aplicación informática para teléfonos móviles ideada para el control de sesiones de ejercicio domiciliario en claudicantes. Exponemos también nuestros resultados preliminares. Material y métodos: La aplicación está dise˜nada para teléfonos móviles con sistema operativo Android, tecnología de geolocalización y conexión de datos. Está conectada a una base de datos codificada que preserva el secreto médico. Los datos que se recogen de las sesiones de ejercicio son la fecha, la hora de inicio y de fin, el tiempo dedicado, el número de las paradas realizadas y la velocidad máxima, la velocidad media global y la velocidad entre paradas. Durante el mes de enero de 2014 se reclutó a aquellos pacientes que aceptaran el estudio, poseyeran y entendieran un dispositivo móvil Android con geolocalización y conexión de datos. Los criterios de exclusión del estudio una vez comenzado fueron progresión hacia isquemia arterial crítica, enfermedad intercurrente grave, fallecimiento y ausencia de comunicación con el paciente. Se recogieron las principales morbilidades y los resultados de los cuestionarios de calidad de vida SF36 y EuroQol 5D. Se midió el tiempo de primera consulta y el tiempo dedicado por semana y paciente durante un seguimiento de 28 días. Se calculó el cumplimiento de las sesiones con respecto a las sesiones pactadas con cada paciente, con un mínimo de 2 semanales. Resultados: Un total de 5 pacientes fueron incluidos, con edad media de 59,3 a˜nos (mediana 52; rango 40-80). De ellos 2 se excluyeron, uno por progresión a isquemia crítica y otro por ausencia de comunicación. El tiempo medio dedicado por consulta nueva fue de 29,1 min (mediana 27,5; rango 45-20). El cumplimiento de las sesiones fue del 100% en 2 pacientes y del 63% en otro. El tiempo dedicado en el seguimiento semanal por paciente fue de 1,68 min. Conclusiones: CReTe es una herramienta aplicable a nuestro medio que precisa de estudios mayores para demostrar su utilidad.Objective: The preliminary results are presented on the use of a new application for mobile phones designed to control home exercise sessions in claudication.Materials and methods: The application is designed for Android systems with geolocation tech-nology and Internet connection. It is connected to a database encoded to ensure medical confidentiality. The data collected from the exercise sessions were the date, start time and end time, the time spent, the number of stops made, and the maximum speed, average speed and overall speed between stops. During the month of January 2014 patients who accepted and understood the study, and possessed an Android mobile device with geolocation and data connection, were enrolled. The exclusion criteria, 11 the study started, were progression to arterial ischemia, severe intercurrent illness, non-communication with the patient, and death. Major morbidities and results of quality of life questionnaires SF36 and EuroQol 5 D were collec-ted. Time of first consultation and time spent per week per patient during a 28-day follow-up was recorded. Compliance as regards the agreed sessions was calculated for each patient, with a minimum of 2 weeks.Results: The study included 5 patients with a mean age 59.3 years (median 52; range 40-80). Of these, 2 were excluded, one for progression to critical ischemia and another for non-communication. The average time spent in a new consultation was 29.1 minutes (median 27.5, range 45-20). The compliance with the sessions was 100% in 2 patients, and 63% in another. Time spent in the weekly monitoring per patient was 1.68 minutes.Conclusions: CReTe is an applicable tool in our environment that requires further study to demonstrate its usefulness

    Design and Implementation of a Pressure Monitoring System Based on IoT for Water Supply Networks

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    Increasing the efficiency of water supply networks is essential in arid and semi-arid regions to ensure the supply of drinking water to the inhabitants. The cost of renovating these systems is high. However, customized management models can facilitate the maintenance and rehabilitation of hydraulic infrastructures by optimizing the use of resources. The implementation of current Internet of Things (IoT) monitoring systems allows decisions to be based on objective data. In water supply systems, IoT helps to monitor the key elements to improve system efficiency. To implement IoT in a water distribution system requires sensors that are suitable for measuring the main hydraulic variables, a communication system that is adaptable to the water service companies and a friendly system for data analysis and visualization. A smart pressure monitoring and alert system was developed using low-cost hardware and open-source software. An Arduino family microcontroller transfers pressure gauge signals using Sigfox communication, a low-power wide-area network (LPWAN). The IoT ThingSpeak platform is used for data analysis and visualization. Additionally, the system can send alarms via SMS/email in real time using the If This, Then That (IFTTT) web service when anomalous pressure data are detected. The pressure monitoring system was successfully implemented in a real water distribution network in Spain. It was able to detect both breakdowns and leaks in real time
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