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Irrigation systems significantly enhance agricultural productivity but are also substantial consumers of water, energy, and natural resources. The need to optimize their design encouraged agronomic engineering to develop various methods for improving the design and management of these irrigation networks. This development focuses on creating a tool to define the optimal flow distribution according to the system's irrigation or consumption needs, thereby determining the design flows. The aim is to optimize the design of pipe diameters to improve sustainability (i.e., reducing CO2 emissions, minimizing service pressure, and maximizing recoverable energy within the system). These principles ensure a better evaluation of sustainable development goals within agricultural production. The proposed procedure develops a strategy to define the best-fitting distribution using a multicriteria solution. As novel, the research develops a tool, which characterizes flow distributions deviating from the classic Clement's formulation used in irrigation systems. The proposed method was applied in a Mediterranean irrigation system in Spain, achieving a correlation coefficient above 0.9 in the model. This methodology addresses design criteria in terms of sustainability and reduces energy consumption in networks. It achieved material savings of 6.01 % compared to the observed network, reducing CO2 emissions between 5.61 and 5.72 TnCO2/ha over its lifecycle.

A new methodology, called HY4RES models, includes hybrid energy solutions (HESs) based on the availability of renewable sources, for 24 h of water allocation, using WaterGEMS 10.0 and PVGIS 5.2 as auxiliary calculations. The optimization design was achieved using Solver, with GRG nonlinear/evolutionary programming, and Python, with the non-dominated sorting genetic algorithm (NSGA-II). The study involves the implementation of complex multi-objective and multi-variable algorithms with different renewable sources, such as PV solar energy, pumped hydropower storage (PHS) energy, wind energy, grid connection energy, or battery energy, and also sensitivity analyses and comparisons of optimization models. Higher water allocations relied heavily on grid energy, especially at night when solar power was unavailable. For a case study of irrigation water needs of 800 and 1000 m3/ha, the grid is not needed, but for 3000 and 6000 m3/ha, grid energy rises significantly, reaching 5 and 14 GWh annually, respectively. When wind energy is also integrated, at night, it allows for reducing grid energy use by 60% for 3000 m3/ha of water allocation, yielding a positive lifetime cashflow (EUR 284,781). If the grid is replaced by batteries, it results in a lack of a robust backup and struggles to meet high water and energy needs. Economically, PV + wind + PHS + grid energy is the most attractive solution, reducing the dependence on auxiliary sources and benefiting from sales to the grid.

A new methodology for hybrid energy systems (HESs) was developed, namely the HY4RES model, tailored for the water sector, covering hybrid energy objective functions and grid or battery support using optimization algorithms in Solver, MATLAB, and Python, with evolutionary methods. HOMER is used for hybrid microgrids and allows for comparison with HY4RES, the newly developed model. Both models demonstrated flexibility in optimizing hybrid renewable solutions. This study analyzed an irrigation system for 3000 m3/ha (without renewables (Base case) and the Proposed system—with PV solar and pumped-hydropower storage to maximize cash flow over 25 years). Case 1—3000 m3/ha presented benefits due to PV supplying ~87% of energy, reducing grid dependency to ~13%. Pumped-hydropower storage (PHS) charges with excess solar energy, ensuring 24 h irrigation. Sensitivity analyses for Case 2—1000—and Case 3—6000 m3/ha—highlighted the advantages and limitations of water-energy management and system optimization. Case 2 was the most economical due to lower water-energy needs with noteworthy energy sales (~73.4%) and no need for the grid. Case 3 led to increased operating costs relying heavily on grid energy (61%), with PV providing only 39%. PHS significantly lowered operating costs and enhanced system flexibility by selling excess energy to the grid.

Water utilities are concerned about the issue of pipeline collapses, as service interruptions lead to water shortages. Pipeline collapses can occur during the maintenance phase when water columns compress entrapped air pockets, consequently increasing the pressure head. Analysing entrapped air pockets is complex due to the necessity of numerically solving a system of differential equations. Currently, water utilities need more tools to perform this analysis effectively. This research provides a numerical solution to the problem of entrapped air pockets in pipelines which can be utilised to predict filling operations. The study develops an analytical solution to examine the filling process. A practical application is shown, considering a 600 m long pipeline with an internal diameter of 400 mm. Compared with existing mathematical models, the results of the new analytical equations demonstrate their effectiveness as a new tool for computing the main hydraulic and thermodynamic variables involved in this issue.

Alterations in annual temperature and precipitation patterns are imposing heightened strain on both urban and agricultural systems. The insufficiency of available water resources to satisfy the escalating demand necessitates a concerted effort to optimize alternative sources. In the context of agriculture, the utilization of treated water is currently executed on a sporadic basis. The elevated energy expenditures and the absence of regulatory frameworks in these systems contribute to a substantial portion of these resources being discharged into natural water bodies, or in the case of coastal municipalities, near the sea. This research endeavors to proffer a comprehensive strategy aimed at eliminating the discharge of treated water into the sea. It proposes the annual allocation of 16.7 hm3 of treated water to irrigation communities grappling with acute water deficits. The strategy, when applied to a tangible case study, ensures the reliable provision and distribution of the entire designated volume. This approach takes into account the fluctuating agricultural demands through the implementation of hybrid systems boasting an installed capacity of 15 MW. Additionally, it establishes the deployment of pumped hydro-storage reservoirs to regulate and secure the requisite energy for distribution and the osmosis process involved in treating a portion of the reclaimed water, thereby presenting a high-quality solution amenable to agricultural consumption.

In 2030, the world population will exceed 8.5 billion, increasing the challenges to satisfy basic needs for food, shelter, water, and/or energy. Irrigation plays a vital role in productive and sustainable agriculture. In the current context, it is determined not only by water availability but also by optimal management. Several authors have attempted to measure the performance of irrigation networks through various approaches in terms of technical indicators. To improve the sustainability in the pipe sizing of the pressurised irrigation networks, 25 different models were evaluated to discuss the advantages and disadvantages to consider in future methodologies to size water systems, which guarantee the network operation but contribute to improving the sustainability. They enable water managers to use them as tools to reduce a complex evaluation of the performance of a system, and focusing on better management of resources and sustainability indicators for agricultural ecosystems are clear and objective values.

Using pumps operating as turbines (PATs) offers the possibility of increasing the sustainability of water and energy systems by recovering the excess energy that would be otherwise lost in pressure-reducing valves or head loss chambers. Regarding on-grid applications, there have been many research works, and PATs have been implemented in several ways. However, more research still needs to be done on optimizing the efficiency and stability of PATs operating in off-grid systems. This work contributes to the development of stable direct current (DC) off-grid electric systems based on PATs using a self-excited induction generator (SEIG). In this context, a methodology is proposed, based on the hydraulic, mechanical, and electric subsystems, to define the PAT-SEIG operational area to maximize energy conversion and system efficiency. These limits depend highly on the capacitor value, rotational speed, and electric load. In addition, an analytical model is proposed to estimate the PAT-SEIG operation under specific conditions. With this, water managers can design and optimize an off-grid PAT-SEIG system and define the best hydraulic machines, electronic equipment, and control elements to maximize energy conversion within the target of operational limits. Two micro PAT-SEIG setups were implemented in the hydraulic laboratory of IST/CERIS under typical operating conditions to validate the proposed methodology. The system’s maximum efficiency and operational limits can be adapted using different capacitor values for the excitation of the SEIG. Considering the nominal efficiencies of the system’s components, the maximum p.u. efficiency obtained for each PAT-SEIG system was between 0.7 and 0.8 p.u.

The world’s water infrastructures suffer from inefficiencies, such as high energy consumption and water losses due to inadequate management practices and feeble pressure regulation, leading to frequent water and energy losses. This strains vital water and energy resources, especially in the face of the worsening challenges of climate change and population growth. A novel method is presented that integrates micro-hydropower plants, with pumps as turbines (PATs), in the water network in the city of Funchal. Sensitivity analyses evaluated the microgrid’s response to variations in the cost of energy components, showing favorable outcomes with positive net present value (NPV). PV solar and micro-wind turbines installed exclusively at the selected PRV sites within the Funchal hydro grid generate a combined 153 and 55 MWh/year, respectively, supplementing the 406 MWh/year generated by PATs. It should be noted that PATs consistently have the lowest cost of electricity (LCOE), confirming their economic viability and efficiency across different scenarios, even after accounting for reductions in alternative energy sources and grid infrastructure costs.

This study aimed to determine the level of satisfaction of surgical staff nurses and clients on the nursing management of postoperative complications rendered by the staff nurses in the different hospitals in Iriga City. This study specifically aimed to determine the personal and professional attributes of the surgical staff nurses in terms of age, gender, educational attainment, seminars or training, and years of experience in the surgical area; to determine the level of satisfaction with the nursing care for preventing postoperative complications along nursing care, early ambulation, adequate nutrition, skin breakdown, and pressure source, adequate pain management; to determine if there a significant difference on the level of satisfaction on the nursing care for preventing post-operative complications of the patients and the nurses; to determine if is there a significant relationship between personal and professional attributes and interventions rendered by the surgical staff nurses; and to identify measures that can be proposed based on the findings of the study. The study is descriptive-correlational research. Frequency count, percentage techniques, weighted means, and the Wilcoxon Rank-Sum Test of Two-Sample Test were employed as statistical tools. The result showed that a majority of the surgical staff nurses’ age ranges from 25 years old and below, mostly female, baccalaureate degree holders, 6 to 10 years in service, and attended training in the surgical area. Staff nurses and patients are much satisfied with the nursing management in preventing postoperative complications. Likewise, there is no significant difference in the level of satisfaction between the clients and the staff nurses in post-operative complications. Also, there is no significant relationship between the profile of the staff nurses and the level of satisfaction with the nursing care of preventing post-operative complications of the patients. A Postoperative Management Brochure was developed to serve as a guide for effective postoperative care.

Este texto recuerda y enaltece al hombre, y a la vez al polifacético escritor y profesor universitario Juan Valdano, quien cultivó el ensayo, la investigación, la novela y el cuento. Evoca al ecuatoriano que celebró al país al dedicar más de una obra a nuestra forma de ser, a nuestra idiosincrasia y a nuestro sentido de nación. Estudió Filosofía y Letras en Cuenca, Filología Hispánica en Madrid y Letras Francesas en Provence. Miembro de la Academia Ecuatoriana de la Lengua, recibió varios premios y distinciones como el Premio Eugenio Espejo por su trayectoria y sus obras. Como homenaje a su memoria, se añade un comentario crítico a una antología personal de sus cuentos titulada Juegos de Proteo (2012).

The selection of pumps as turbines (PATs) for their respective use in energy optimisation systems is a complicated task, because manufacturers do not provide the characteristic curves. For this reason, some research has been carried out to predict them with computational fluid dynamics (CFD) and mathematical models. The purpose of this study is to validate these two prediction methodologies of flow (Q) vs. head (H) curves through numerical modelling using the computational package OpenFOAM, together with a comparison with the experimental data obtained from a PAT for the case in which the nominal rotation speed of the machine varies. Depending on the configuration and working conditions of the PAT, the simulation performed with OpenFOAM was validated by calibrating it with the nominal curve of the pump and with another simulation performed with CFD workbench SOLIDWORKS FloEFD. Subsequently, the second methodology related to the analyses and mathematical models proposed to predict the Q vs. H curves were also validated with new models in OpenFOAM and the experimental data. The results show that these prediction methods are effective when a machine’s operating point is close to the BEP (best efficient point). The absolute error ranges obtained with these two prediction methodologies for rotation speeds of 880 rpm, 1020 rpm, 1200 rpm, and 1500 rpm are between 5 and 24%, 2 and 17%, 0 and 12%, and 1 and 24%, respectively.

The present paper focuses on the selection of parameters that maximize electrical energy production of a horizontal axis wind turbine using Python programming language. The study takes as reference turbines of Villonaco wind field in Ecuador. For this aim, the Blade Element Momentum (BEM) theory was implemented, to define rotor geometry and power curve. Furthermore, wind speeds were analyzed using the Weibull probability distribution and the most probable speed was 10.50 m/s. The results were compared with mean annual energy production of a Villonaco’s wind turbine to validate the model. Turbine height, rated wind speed and rotor radius were the selected parameters to determine the influence in generated energy. Individual increment in rotor radius and rated wind speed cause a significant increase in energy produced. While the increment in turbine’s height reduces energy generated by 0.88%.

This study aimed to investigate the perception of STEM students (n = 147) on using mobile Augmented Reality (AR) across gender and learning styles in physics online classes. It utilized embedded mixed-method research and purposive sampling. An instrument named Students Perception in Integrating Mobile AR in Physics Class was developed and has undergone a series of validations such as item generation from literature review, content validation, cognitive interview, pilot testing, and exploratory factor analysis revealing two factors, CFA with indices that are of acceptable value, and good Cronbach alpha ([alpha] = 0.86) for reliability. Mean, standard deviation, percentages, two samples t-test, and thematic analysis were used to analyze the data. Results revealed that all students have a source of internet connection as well as a device to use and most of them have a very stable to somewhat stable internet connection. Positive feedback was shown in terms of overall learning experience and perception across gender and learning styles. However, in terms of overall usability, females have more ease of use compared to males and kinesthetic learners only have a positive response. It was also found that there is no significant difference across gender. Moreover, the integration of AR in a physics lesson has received excellent responses from both students with and without prior experience in a classroom setting. All of the difficulties the students encountered were technological in nature. There are also opportunities to improve the integration of mobile AR in the technical and learning process. These results suggest that teachers should integrate mobile AR in online physics classes but should consider factors such as Internet connection, device, gender, and learning styles in developing the application.

This research proposes a methodology with multi-objective optimization for the placement of Pumps operating As Turbines (PATs), energizing street lighting, devices for monitoring the water network, and charging stations for small electric vehicles such as bikes and scooters. This methodology helps to find the most profitable project for benefiting life quality and energy recovery through pumps operating as turbines, replacing virtual pressure reduction valves to locate the best point for decreasing pressure. PATs are selected by maximizing power recovery and minimizing pressure in the system as well as maximizing recoverable energy. Benefits analyzed include the reduction of carbon dioxide emissions and fuel use, as well as the saving of electricity consumption and benefiting socio-economic impact with street lighting, monitoring, and charging station. It was considered that each PAT proposed by the methodology will supply a street light pole, a station for monitoring the water network, and a charging station; under these established conditions, the return on investment is up to 1.07 at 12 years, with a power generation of 60 kWh per day.

The wastewater treatment plants (WWTP) treat the water from domestic and industrial use so that its discharge, once it passes through them, is harmless to the environment. However, large amounts of energy are necessary to carry out this process. Therefore, energy and process optimization are a key issue within these type of plant. One of the possibilities within the WWTPs is the recovery of hydraulic energy. This paper presents alternatives for the recovery of hydraulic energy, through the use of hydraulic micro-machinery such as PATs or hydrostatic pressure wheels. This type of machinery is capable of recovering a part of that energy that until now it was not possible to recover, in a more economical way and assuming an improvement for plants that have the possibility of installing it. In the here described case study, savings of over 4% were achieved with periods of return on investment of less than 5 years.

Uno de los principales problemas de las plantas de tratamiento de agua es el elevado consumo energético al que tienen que hacer frente. Por ello, reducir el consumo energético es objetivo prioritario para dichas instalaciones. Este trabajo propone un modelo de programación matemática para la planificación de la capacidad y gestión de instalaciones depuradoras de agua, que mediante dilución, re-duzca el consumo energético en la fase de aireación. Dicho modelo presenta como novedad la inclusión de la variable tiempo, generando un modelo cuasiestacionario, que ha sido aplicado a un caso real de estudio.

El establecimiento de los nuevos planes de estudio en el Espacio Europeo de Educación Superior así como la inclusión de las competencias transversales en la evaluación de los títulos junto la aparición de las nuevas herramientas de las tecnologías de la información ha propiciado el desarrollo de la innovación en las estrategias del aprendizaje. Dentro de la Universitat Politècnica de València, este hecho no ha pasado desapercibido y la Escuela Politécnica Superior de Alcoy ha demostrado una alta participación en lo referente a la innovación educativa. La presente comunicación muestra los proyectos de innovación y mejora educativa llevados a cabo dentro de este centro así como los índices de rendimiento y satisfacción del alumnado desde la implantación de los grados de ingeniería en la Escuela Politécnica Superior de Alcoy.

In Ecuador, the implementation of hydroelectric power plants has had a remarkable growth in the energy sector due to its high efficiency, low environmental impact, and opportunities to generate employment. One of the sectors with the greatest benefits from this type of energy has been the rural sector, where several small-scale hydroelectric plants (0.5 MW–10 MW) have been installed, usually with Pelton turbines. Although these turbines are highly efficient, one of the challenges is to obtain the optimal geometry of the bucket to take advantage of the greatest amount of energy from the water, avoiding the separation of the fluid. In this context, this study focuses on the development of an analytical and iterative methodology that allows for the determining of the appropriate dimensions of the buckets to achieve maximum turbine efficiency. For that, a parametric model has been proposed considering the dimensions and main angles of the bucket, the net hydraulic head and the working flow, as well as the power losses. The results of the model have been validated by means of CFD and by contrasting the experimental data obtained from the “Illuchi N2” Hydroelectric Power Plant in Ecuador, and it is concluded that it is possible to improve the turbine efficiency by up to 4%.

The constant growth of the population and the increase in the need for resources create challenges, and it is necessary to seek more sustainable solutions to manage them more adequately and efficiently. In recent years, the use of renewable energy systems has increased, in which water distribution networks are no exception. Pumps operating as turbines (PATs) are an innovative solution with enormous potential to achieve these sustainable development goals. As a means of improving sustainability, in this research, an optimized regulation tool is developed to maximize the recovered energy in the system using PATs in water distribution networks (WDNs). This is possible due to the use of empirical methods for the estimation of the characteristic curves. The tool was developed in Simulink MATLAB, in which the optimization and iterative steps were carried out. It is based on the intended methodology and applied to a real case study. When implementing the tool, the results given are the hydraulic–electrical regulation strategies, where the number of machines working, the frequency inverter setpoint, and the degree of opening of the pressure-reducing valves (PRV) is defined for any given time. After the analysis in the case study, the tool recovered 28% of the supplied energy in the system. This daily recovered energy was above 7160 kWh, and it contributed to an increase in efficiency and sustainability.

Nowadays, in the management of water distribution networks (WDNs), particular attention is paid to digital transition and the improvement of the energy efficiency of these systems. New technologies have been developed in the recent years and their implementation can be crucial to achieve a sustainable level of water networks, namely, in water and energy losses. In particular, Digital Twins (DT) represents a very innovative technology, which relies on the integration of virtual network models, optimization algorithms, real time data collection, and smart actuators information with Geographic Information System (GIS) data. This research defines a new methodology for an efficient application of DT expertise within water distribution networks. Assuming a DMA of a real water distribution network as a case study, it was demonstrated that a fast detection of leakage along with an optimal setting of pressure control valves by means of DT together with an optimization procedure can ensure up to 28% of water savings, contributing to significantly increase the efficiency of the whole system.

Hydropower is a well-known technology, applied worldwide for electricity generation from renewable sources. Within the current framework, some studies have started to consider its application to existing urban water systems, to harness an excess of energy that otherwise would be wasted. This research sought to determine a methodology to assess the potential of hydropower application to wastewater treatment plants (WWTPs), regarding different aspects of sustainability. Firstly, previously developed methodologies for potential assessment in this sector at a country level were analyzed. Secondly, data from existing real case studies were gathered from publicly available documents and a theoretical analysis of their actual performance was conducted to validate assumptions made in the previous methodologies. As a result, the proposed new approach suggests adapting methodologies for potential assessment at a lower level, considering possible driving factors, other than economic feasibility. To define the study area, the management model scope should be considered. The power to determine the cut-off point for a WWTP to be considered as a potential site, is proposed to be lowered according to technical feasibility. Additionally, bearing in mind the sustainability concept, social or environmental factors should also be introduced in the methodology, tailored to the region being assessed. This novel perspective could provide a closer approach to the most likely decision-making level for these kinds of strategies in the wastewater industry.

Genetic selection has remarkably helped U.S. dairy farms to decrease their carbon footprint by more than doubling milk production per cow over time. Despite the environmental and economic benefits of improved feed and milk production efficiency, there is a critical need to explore phenotypical variance for feed utilization to advance the long-term sustainability of dairy farms. Feed is a major expense in dairy operations, and their enteric fermentation is a major source of greenhouse gases in agriculture. The challenges to expanding the phenotypic database, especially for feed efficiency predictions, and the lack of understanding of its drivers limit its utilization. Herein, we leveraged an artificial intelligence approach with feature engineering and ensemble methods to explore the predictive power of the rumen microbiome for feed and milk production efficiency traits, as rumen microbes play a central role in physiological responses in dairy cows. The novel ensemble method allowed to further identify key microbes linked to the efficiency measures. We used a population of 454 genotyped Holstein cows in the U.S. and Canada with individually measured feed and milk production efficiency phenotypes. The study underscored that the rumen microbiome is a major driver of residual feed intake (RFI), the most robust feed efficiency measure evaluated in the study, accounting for 36% of its variation. Further analyses showed that several alpha-diversity metrics were lower in more feed-efficient cows. For RFI, [Ruminococcus] gauvreauii group was the only genus positively associated with an improved feed efficiency status while seven other taxa were associated with inefficiency. The study also highlights that the rumen microbiome is pivotal for the unexplained variance in milk fat and protein production efficiency. Estimation of the carbon footprint of these cows shows that selection for better RFI could reduce up to 5 kg of diet consumed per cow daily, potentially reducing up to 37.5% of CH4. These findings shed light that the integration of artificial intelligence approaches, microbiology, and ruminant nutrition can be a path to further advance our understanding of the rumen microbiome on nutrient requirements and lactation performance of dairy cows to support the long-term sustainability of the dairy community.

The present research depicts an analysis of the implementation of computational fluid dynamics (CFD) in the study of pumps such as turbines and PATs. To highlight the benefits of CFDs for PAT studies, results from both experimental tests have been compared to better understand the reproduction error phenomena. For this, data analysis used in successful models has been applied to determine variables and parameters, and to report a low relative error. The results show that most of the studies focused on fixed speed rotation with some cases of variable speed rotation. Furthermore, there is not enough information in the academic literature for PAT of axial and mixed flows with fixed and variable speed. Finally, turbulence models based on Reynolds average Navier–Stokes (RANS) have been used to simulate PATs with fixed speed rotation in most cases.

New technologies for water pressurized systems try to implement the introduction of strategies for the improvement of the sustainable indicators. One of these technologies is the implementation of pumps working as turbines. The use of these recovery machines was proposed some years ago, and the interest in this technology has increased over the last years. The simulation of these machines is necessary when analyzing pressurized water systems, or when optimization procedures are proposed for their management, great care must be taken. In these cases, the knowledge of the operation curves is crucial to reach accurate results. This study proposes different regression expressions to define three operational curves when the machines operate under variable rotational speed. These curves are the best efficiency head, the best power-head and the best power flow. The here proposed methods were compared with other five published methods. The comparison shows the proposed method was the best when it is compared with the rest of the published procedures, reducing the error values between 8 and 20%.

Water is one of the most valuable resources for humans. Worldwide, leakage levels in water distribution systems oscillate between 10% and 55%. This causes the need for constant repairs, economic losses, and risk to the health of users due to possible pathogenic intrusion. There are different methods for estimating the level of leakage in a network, depending on parameters such as service pressure, orifice size, age and pipe material. Sixty-two water distribution networks were analyzed to determine the leakage method used, the calibration method, and the percentage of existing leaks. Different efficiency indicators were proposed and evaluated using this database. Several cases of installation of pumps working as turbines (PATs) in water distribution networks were analyzed in which the use of these recovery systems caused a pressure drop, reducing the level of leaks and recovering energy.

Sustainability and efficiency in irrigation are essential in the management of the water–energy–food nexus to reach the Sustainable Development Goals in 2030. In irrigation systems, the reduction of energy consumption is required to improve the system efficiency and consequently the sustainability indicators of the water network. The use of pumps working as turbines (PATs) has been a feasible solution to recover the excess of energy where pressure reduction valves are installed. This research demonstrates the use of PATs under steady and unsteady conditions by analyzing the application in a real irrigation networks located in Vallada (Valencia, Spain). The study shows the possibility of recovering 44 MWh/year using PATs installed upstream of the irrigation hydrants. The real behavior of the PAT operation in a stand-alone recovery energy solution allowed analysis of the flow, head and efficiency variation as a function of the rotational speed, as well as the minimum capacitance to self-excite the generator and the resistive load of the electrical circuit. The PAT limit is examined in terms of the overpressure induced by a fast closure manoeuvre of hydrants, and the runaway conditions due to the disconnection from the electrical load.

Pérez-Sánchez, M., Sánchez-Romero, F. J., & López-Jiménez, P. A. (julio-agosto, 2017). Nexo agua-energía: optimización energética en sistemas de distribución. Aplicación “Postrasvase Júcar-Vinalopó”, España. Tecnología y Ciencias del Agua, 8(4), 19-36. En ocasiones, la realización de transferencias de volúmenes de agua entre cuencas es la única solución al déficit hídrico para algunas zonas agrícolas. Tal es el caso del mediterráneo español, concretamente el sur de la provincia de Alicante. De manera histórica, esta área ha presentado un balance hídrico deficitario entre necesidades de riego y recursos, provocando la sobreexplotación de sus acuíferos. Para paliar este impacto medioambiental se articuló una transferencia de volúmenes entre las cuencas de los ríos Júcar y Vinalopó. Un sistema hidráulico a presión fue el encargado de trasvasar agua entre cuencas y distribuirlas a las superficies de regadío. En el presente artículo se describe la metodología utilizada para optimizar el sistema agua-energía, basado en Epanet, para que una vez calibrado se utilice como herramienta de explotación del sistema. Dicho modelo permite analizar la distribución de volúmenes y caudales en función de la demanda agrícola existente en cada balsa receptora. Unido a la distribución hidráulica se realiza un estudio profundo de las posibles relaciones hidroenergéticas en el sistema conjunto, llegando a obtener un valor máximo de energía recuperable teórica de 18 418 MWh/año. Así, se determina la viabilidad de aprovechar saltos hidráulicos para aumentar la eficiencia conjunta en la distribución.

Las líneas eléctricas trifásicas de alta tensión son elementos de difícil modelado debido a una serie de fenómenos que a otros niveles de tensión pueden resultar despreciables. Para el cálculo de los parámetros básicos (resistencia, inductancia y capacidad) con los que crear modelos sencillos (ya sea de parámetros concentrados o distribuidos) válidos para simular el funcionamiento de las líneas, se desarrollan expresiones de una complejidad que dificulta su asimilación. Para facilitar el alineamiento enseñanza-aprendizaje del alumno, se ha desarrollado una colección de laboratorios virtuales con Matlab© para facilitar la comprensión del funcionamiento de las líneas de alta tensión. En este artñiculo se muestra uno de estos laboratorios que permite representar la geometría de líneas aéreas de alta tensión y computar el cálculo de sus parámetros.

Las auditorías energéticas son herramientas que permiten analizar la situación de las redes de distribución, donde el consumo energético depende del patrón de caudal anual (RQ). En este trabajo se desarrolla una metodología para poder comparar la huella energética del agua (HEA) a través de un balance energético con diferente RQs. El objetivo es determinar el comportamiento energético de una red en base a RQ. El estudio analiza cuatro redes (dos de abastecimiento y dos de riego) mostrando que aquellas que presentan un RQ menos variable tienen un menor consumo de energía total (5.22, 3.21, y 4.01%) y de fricción (28.57, 21.42 y 25%) frente a la red con un RQ más variable. Como novedad, el trabajo define el parámetro HEA adimensional, el cual permite comparar la HEA entre diferentes redes, pudiendo ser introducido como índice de sostenibilidad en el dimensionado junto a los criterios técnicos y económicos.

Pressurized water systems are designed to guarantee the flow demanded by each user, considering the minimum required pressure. The pressurized water systems have increased water efficiency since their implantation, but they also increased the consumed energy and therefore, the greenhouse gasses emissions. The present manuscript develops the proposal of the sustainable indicators that were selected through deep review. These indicators are related to social-cultural, economic, and environmental criteria. Furthermore as novelty, they were described and applied on a pressurized water network, complementing the energy indexes usually used in the energy audit. To reach the improvement of the sustainability in water systems, new strategies should be developed to improve all sustainability criteria, included the water and energy efficiency. These strategies were developed and analyzed by using of specific hydraulic software (i.e., EPANET) and they were based on operation rules to estimate the hydraulic values (pressure and flow). The operation and the regulation strategies were applied on a particular case study, in which, the energy saving was 12.26%, the cost saving was 15.54%, the reduction of energy footprint of water was 15.04%, and the decrease of GHG was 12.26% although the increase of the distributed volume was 9.07%. Besides, the supply guarantee for both irrigation and urban water distribution systems was increased in the new proposal of water management. Finally, the proposal to replace of a pressure reduction valve by a sustainability recovery machine (e.g., pump working as turbine) contributed with a generation of renewable energy equal to 103,710 kWh/year.