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“El Araceli” Non-destructive Test from the “Misterio de Elche” Play

Thu, 16 Jan 2025 18:34:41 GMT

Título : “El Araceli” Non-destructive Test from the “Misterio de Elche” Play Autor : VELASCO SANCHEZ, EMILIO; Navarro-Arcas, Abel; Marco Lozano, Sixto Manuel Resumen : In the city of Elche, every year, on August 14 and 15, it is celebrated a sacred musical drama of the death, the passage into heaven (known as the Assumption) and the crowning of the Virgin Mary. This event, known as “Misterio de Elche” play is unique in Europe. Since the mid-fifteenth century it has been performed in the Basilica of Saint Mary and in the streets of the old city of Elche, situated in the region of Valencia. The stage has two levels: the horizontal “terrestrial” stage and the vertical “celestial” stage, characteristic of the medieval mystery play. Ancient aerial machinery is used to enhance the spectacle by means of special effects. From the upper level, several aerial devices are raised and lowered in a controlled manner. These devices are called “La Mangrana”, “El Araceli” and “La Santísima Trinidad”. To give context to the reader, it is important to highlight that “El Araceli” is a device prepared to support five people situated in a special layout. The original supporting structure of this apparatus was made up of forged steel, wood and hemp ropes, but with the passage of time, some successive renovations were required. In 2010, wear was detected in some parts by the technical department that could cause security problems. Due to this circumstance, it was ordered a deep study. This paper analyzes a non-destructive test that was carried out on “El Araceli”. A data acquisition system customized to the device was used to verify that the apparatus was suitable for the loads for which it was designed.

The Hoist of the Aerial Rigging of the Mystery of Elche

Thu, 16 Jan 2025 18:27:14 GMT

Título : The Hoist of the Aerial Rigging of the Mystery of Elche Autor : VELASCO SANCHEZ, EMILIO; Navarro-Arcas, Abel; Marco Lozano, Sixto Manuel Resumen : In the town of Elche, during the 14th and 15th of August and without significant interruption since the last third of the XVth century, festivities are held in honor of its patron saint, the Virgin of the Assumption. This theatrical performance was declared IntangibleWorld Heritage in 2001. The representation of the final days, death, assumption into heaven and coronation of the Virgin Mary is the highlight of the performance that takes place inside the temple of the Basilica of Saint Mary. This representation, unique in the world, is performed in song after converting the whole of the interior of the temple into a huge stage, with its corresponding rigging fitted with composite machinery, a double hoist, which allows lowering and raising to a height of 27 m. The aerial devices are occupied by singers, sometimes as many as five, reaching a weight of up to 600 daN, and even the simultaneous maintenance of two of the devices in the air. The lifting machines installed have undergone various modifications over time. The last of these was undertaken by the architect, Marcos Evangelio, in 1760 and, except for maintenance repairs required over the years and, despite a fire at the church in February 1936, they remain in a similar state to how the architect designed them. Studying them allows us to assess the mechanical assembly in general as very primitive technology, but which, after being used and perfected over the centuries, has allowed it to reach a high degree of precision and efficiency. This paper shows the main mechanical characteristics of the hoist, which is 300 years old.

Short-term load forecasting of multiregion systems using mixed effects models

Sun, 12 Jan 2025 18:11:22 GMT

Título : Short-term load forecasting of multiregion systems using mixed effects models Autor : López García, Miguel; VALERO, SERGIO; Senabre, Carolina Resumen : This paper presents an application of linear mixed models to short-term load forecasting. The starting point of the design is a currently working model at the Spanish Transport System Operator, which is based on linear autoregressive techniques and neural networks. The forecasting system currently forecasts each of the regions within the Spanish grid separately, even though the behavior of the load in each region is affected by the same factors in a similar way. The integration of several regions into a linear mixed model allows using the information from other regions to learn general behaviors present in all regions while also identifying individual deviation in each regions. This technique is especially useful when modeling the effect of special days for which information from the past is scarce. The model described has been applied to the three most relevant regions of the system, focusing on special day and improving the performance of both currently working models used as benchmark.

Standardization of Short-Term Load Forecasting Models

Sun, 12 Jan 2025 18:11:04 GMT

Título : Standardization of Short-Term Load Forecasting Models Autor : López García, Miguel; VALERO, SERGIO; Senabre, Carolina; Gabaldon, Antonio; Aparicio, Juan Resumen : There has been a significant production of load forecasting models over the last 5 years. These models present a wide variety of techniques, most of them using novel artificial intelligence approaches. Load forecasting is a complex matter and it is the result of several processes that, depending on the database, may be of more or less importance. However, most models focus their attention only on one process like the “forecasting engine”, neglecting other processes like variable selection or pre-processing. This paper proposes a standard scheme for load forecasting models that includes all subprocesses within load forecasting. The analysis of load forecasting models through this scheme allows identifying the effect of each process on the overall performance of the model. Also, proposing load forecasting models following this scheme will enhance benchmarking possibilities and hybridization of models. Finally, this paper presents such analysis of an actual load forecasting model.

Short-Term Load Forecasting: Revising How Good We Actually Are

Sun, 12 Jan 2025 18:10:45 GMT

Título : Short-Term Load Forecasting: Revising How Good We Actually Are Autor : López García, Miguel; VALERO, SERGIO; Senabre, Carolina; Gabaldon, Antonio Resumen : This paper proposes the use of an indicator of the predictability of the load series along with an accuracy value such as Mean Average Percentage Error as standard measures of load forecasting performance. Over the last 10 years, there has been a significant increase in load forecasting models proposed in engineering journals. Most of these models provide a description of the inner design of the model, the results from applying this model to a specific data base and the conclusions drawn from this application. However, a single accuracy value may not be sufficient to describe the performance of the model when applied to other data bases. The aim of this paper is to provide researchers with a tool that is able to assess the predictability of a load series and, therefore, contextualize the forecasting accuracy reported. Thirteen different data bases were used to determine its validity.

Net flow characteristics inside an oscillatory reactor equipped with 3 orifice baffles

Sat, 11 Jan 2025 16:29:34 GMT

Título : Net flow characteristics inside an oscillatory reactor equipped with 3 orifice baffles Autor : Muñoz-Cámara, José; Crespí Llorens, Damián; Solano, Juan Pedro; Vicente, P. Resumen : Oscillatory Baffle Reactors (OBR) are often found in industrial processes. This type of device is specially intended for chemical reactions with high residence time and moderate or high mixing requirements (usually achieved by increasing the Reynolds number). In order to meet both objectives, a standard pipe heat exchanger would be too big. Therefore, OBRs are designed to produce, on the one hand, a low Reynolds number net flow, which results in a high residence time, and, on the other hand, an oscillatory flow is superimposed to increase mixing. This last effect is enhanced by inserting baffles into the pipe, so that their presence, together with the oscillatory flow, produce high pulsating radial velocities to optimize mixing. Besides, as an additional benefit, heat transfer enhancement due to the enhanced convection is also expected. Prior studies have proved OBRs to be very effective for the mentioned objectives, and annular baffle designs have been studied in depth. However, to date, there are only preliminary studies regarding other baffle geometries. The present work presents a complete study of an oscillatory reactor which uses three orifice baffles. The study combines different experimental techniques which provide a full overview of the flow field and its characteristics.

Heat transfer enhancement through the use of an oscillatory flow in circular-orifice baffled tubes: ane xperimental study

Sat, 11 Jan 2025 16:26:50 GMT

Título : Heat transfer enhancement through the use of an oscillatory flow in circular-orifice baffled tubes: ane xperimental study Autor : Muñoz Cámara, José; Crespí Llorens, Damián; Solano, Juan Pedro; Quiles, P.V. Resumen : This work presents an experimental study of the flow pattern in tubes with equally-spaced circular-orifice baffles. Particle Image Velocimetry (PIV) technique is employed in order to obtain the velocity field of the oscillatory flow in the symmetry plane of the region between two consecutive baffles. Experiments have been carried out for oscillatory Reynolds numbers ranging from Reosc =26to Reosc =1500. Theinstantaneousand cycle average f low fields have been obtained for the experiments. The flow has been found to have laminar regime characteristics for Reosc < 100 and to be unstable for about Reosc > 140. For all tested conditions, a recirculation bubble has been detected when the change in direction of the oscillatory motion takes place. Besides, the bubble is displaced along the cell tank by the flow. This bubble results in some mass transfer between core and peripheral regions of the flow. Furthermore, when the limit of about Reosc ≈ 140 is overcome, additional instabilities and vortexes appear, which increase with the Reynolds number, and also increase mass transfer.

Evaluation and Integration of Demand Response and Photovoltaic Generation in Institutional Buildings

Fri, 02 Feb 2024 17:30:35 GMT

Título : Evaluation and Integration of Demand Response and Photovoltaic Generation in Institutional Buildings Autor : García-Garre, Ana; Gabaldon, Antonio; Fernández-Jiménez, Luis A.; Álvarez-Bel, Carlos; Ramírez-Rosado, Ignacio J.; VALERO, SERGIO; Senabre, Carolina Resumen : Buildings are an important segment from the point of view of the overall consumption and the flexibility or change in their demand through Demand Response, Energy Efficiency and Renewable Sources. The integration of renewables represents an opportunity for buildings because main end-uses (for example heat, cool, and ventilation) follow, at some extend, the potential of solar resource. The problem is that renewable resources are evaluated through simulators from average conditions (irradiation, external temperature) but in practice, and in the short term, the generation resource exhibits an important volatility and, in some cases, the integration of renewables can produce not only benefits but risks for the customer from an economic aspect. The aim of this paper is the evaluation of these risks, and to state how Demand Response policies and, of course, Renewable Energy Sources (RES) models, can help to reduce or mitigate these risks and volatility. A real university building is presented to exemplify the methodology.

A Physically-Based Model of Heat Pump Water Heaters for Demand Respose Policies: Evaluation and Testing

Fri, 02 Feb 2024 17:28:36 GMT

Título : A Physically-Based Model of Heat Pump Water Heaters for Demand Respose Policies: Evaluation and Testing Autor : Gabaldon, Antonio; VALERO, SERGIO; García-Garre, Ana; Senabre, Carolina; Álvarez-Bel, Carlos; López, Miguel; Peñalvo, Elisa; Sánchez, Eugenio P. Resumen : The development of Demand Response in residential segments is basic to develop a practical flexibility of demand, because these segments account for up to 40% of the overall demand. Energy Efficiency is another concern for these segments, but unfortunately present scenarios lack a practical coordination between Efficiency and Demand Response. This paper deals with an important problem in residential Demand Response: the determination of the flexibility and response on the demand-side, in this case through loads which can have a high potential for Demand Response and also a considerable interest for energy savings: Heat Pump Water Heaters. A residential load has been fully monitored (temperature, consumption, water flow) in the laboratory to obtain a Physically-Based Model which allows the evaluation of Demand Response options. Moreover, the model helps the aggregator obtain how the flexibility of demand (power, energy, energy payback or rebound effects) can be modified or limited, and how to deal with these characteristics and limitations to engage customers in Electricity Markets.

Comparison of Short-Term Load Forecasting Performance by Neural Network and Autoregressive Based Models

Fri, 02 Feb 2024 16:35:55 GMT

Título : Comparison of Short-Term Load Forecasting Performance by Neural Network and Autoregressive Based Models Autor : López, Miguel; VALERO, SERGIO; Senabre, Carolina; Gabaldon, Antonio Resumen : In the past decade, many techniques ranging from statistical methods to complex artificial intelligence systems have been proposed by implementing their application to an electric system and highlighting its performance; usually providing a measure of accuracy like RMSE over a definite period. However, there is little research in which a fair comparison among methods is demonstrated, and it is difficult to determine which method would be better suited to a particular electric system or data set. This paper analysis one of the forecasting models running at the National Transport Operator of the Spanish system (REE), which is based on both autoregressive and neural network techniques. The results of this paper help to determine under which circumstances each of the models shows a better performance, which periods are more accurately forecasted by each model and provide valid criteria to choose one or the other depending on the characteristics of the application.