Thermally modified (TM) beech wood: compression properties, fracture toughness and cohesive law in mode II obtained from the three-point end-notched flexure (3ENF) test

[EN] The fracture properties of thermally modified beech (Fagus sylvatica) wood (TMW) at 180 degrees and 200 degrees C were evaluated in mode II using the three-point end-notched flexure (3ENF) scheme assisted by three-dimensional (3D) stereovision equipment for obtaining displacements and strains. The compliance-based beam method (CBBM) provided the strain energy release rates (G(II)) of TMW and cohesive laws for both native wood (W) and TMW. Based on the CBBM and equivalent crack length approach (ECLA), G(II) was obtained directly from the force-deflection data. The thermal modification (TM) process reduced the compressive strength by 4.4% and increased the compressive elastic modulus by 38.3%, whereas G(II) was reduced substantially by 40.8% and 67.9% at TM180 degrees C and TM200 degrees C, respectively. TM also increased wood brittleness that was visible on the displacement slip reduction. The resulting mean cohesive models can be used for numerical analyses. The fracture properties of TMW have to be taken into consideration for constructional wood application, when cyclic loading may lead to microcracking and material fatigue.The authors would like to thank COST Action FP1407 (Funder Id: https://dx.doi.org/10.13039/501100000921), the European Commission for funding the InnoRenew CoE project under the Horizon2020 Widespread-Teaming program (grant agreement #739574), the Republic of Slovenia for providing support from the European Regional Development Funds, and the financial support provided by the Internal Grant Agency (IGA) of the Faculty of Forestry and Wood Technology, Mendel University in Brno (LDF_PSV_2016015).Sebera, V.; Redón-Santafé, M.; Brabec, M.; Decky, D.; Cermak, P.; Tippner, J.; Milch, J. (2019). Thermally modified (TM) beech wood: compression properties, fracture toughness and cohesive law in mode II obtained from the three-point end-notched flexure (3ENF) test. Holzforschung. 73(7):663-672. https://doi.org/10.1515/hf-2018-018866367273

IMPLEMENTATION OF A PHOTOVOLTAIC FLOATING COVER FOR IRRIGATION RESERVOIRS

[EN] The article presents the main features of a floating photovoltaic cover system (FPCS) for water irrigation reservoirs whose purpose is to reduce the evaporation of water while generating electrical power. The system consists of polyethylene floating modules which are able to adapt to varying reservoir water levels by means of tension bars and elastic fasteners. (C) 2013 Elsevier Ltd. All rights reserved.Redón-Santafé, M.; Ferrer-Gisbert, P.; Sánchez-Romero, F.; Torregrosa Soler, JB.; Ferran Gozalvez, JJ.; Ferrer Gisbert, CM. (2014). IMPLEMENTATION OF A PHOTOVOLTAIC FLOATING COVER FOR IRRIGATION RESERVOIRS. Journal of Cleaner Production. 66:568-570. doi:10.1016/j.jclepro.2013.11.006S5685706

Use of floating PV plants for coordinated operation with hydropower plants: Case study of the hydroelectric plants of the Sao Francisco River basin

[EN] In recent years, the Brazilian electricity sector has seen a considerable reduction in hydroelectric production and an increase in dependence on the complementation of thermoelectric power plants to meet the energy demand. This issue has led to an increase in greenhouse gas emissions, which has intensified climate change and modified rainfall regimes in several regions of the country, as well as increased the cost of energy. The use of floating PV plants in coordinated operation with hydroelectric plants can establish a mutual compensation between these sources and replace a large portion of the energy that comes from thermal sources, thereby reducing the dependence on thermoelectric energy for hydropower complementation. Thus, this paper presents a procedure for technically and economically sizing floating PV plants for coordinated operation with hydroelectric plants. A case study focused on the hydroelectric plants of the Sao Francisco River basin, where there has been intense droughts and increased dependence on thermoelectric energy for hydropower complementation. The results of the optimized design show that a PV panel tilt of approximately 3 degrees can generate energy at the lowest cost (from R $298.00/MWh to R$312.00/MWh, depending on the geographical location of the FLOATING PV platform on the reservoir). From an energy perspective, the average energy gain generated by the hydroelectric plant after adding the floating PV generation was 76%, whereas the capacity factor increased by 17.3% on average. In terms of equivalent inflow, the PV source has a seasonal profile that compliments the natural inflow of the river. Overall, the proposed coordinated operation could replace much of the thermoelectric generation in Brazil.The authors would like to thank the Brazilian National Council for Scientific and Technological Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq; in Portuguese) for granting a productivity in research scholarship to Prof. Regina Mambeli Barros (PQ2, Process number: 301986/2015-0) and Prof. Geraldo Lúcio Tiago Filho and to the Brazilian Coordination for the Improvement of Higher Education Personnel (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Capes; in Portuguese) for granting the Master of Science scholarship to Naidion Motta Silvério and the Doctorate scholarship to Ivan Felipe da Silva dos Santos.Silverio, N.; Barros, R.; Tiago Filho, GL.; Redón-Santafé, M.; Silva Dos Santos, IF.; De Mello Valerio, VE. (2018). Use of floating PV plants for coordinated operation with hydropower plants: Case study of the hydroelectric plants of the Sao Francisco River basin. Energy Conversion and Management. 171:339-349. https://doi.org/10.1016/j.enconman.2018.05.095S33934917

Project and Design of a Special Agricultural Warehouse Developed in Phases in Valencia (Spain)

[EN] This article describes the developing phases to build warehouses for a Pomelo Company at Valencian County (East of Spain). The warehouses are remarkable because they did not have many intermediate columns. Spatial and lightweight solutions are adopted and described. In the Projects also natural ventilation and lighting have been considered with a successfully result. Erection conditions and Regulations have been taken also account. It has been an inspiration motive for other consultants.Ferrer Gisbert, CM.; Ferrer-Gisbert, P.; Ferran Gozalvez, JJ.; Redón-Santafé, M.; Torregrosa Soler, JB.; Sánchez-Romero, F. (2020). Project and Design of a Special Agricultural Warehouse Developed in Phases in Valencia (Spain). Current Trends in Civil & Structural Engineering. 5(5):1-8. https://doi.org/10.33552/CTCSE.2020.05.000623S185

A new photovoltaic floating cover system for water reservoirs

This paper describes a new photovoltaic floating cover system for water reservoirs developed jointly by the company CELEMIN ENERGY and the Universidad Politecnica de Valencia. The system consists of polyethylene floating modules which, with the use of tension producing elements and elastic fasteners, are able to adapt to varying reservoir water levels. A full-scale plant located near Alicante (Spain) was built in an agriculture reservoir to study the behaviour of the system. The top of the reservoir has a surface area of 4700 m(2) but only 7% of such area has been covered with the fixed solar system. The system also minimizes evaporation losses from water reservoirs. (C) 2013 Elsevier Ltd. All rights reserved.The English revision of this paper was funded by the Universidad Politecnica de Valencia, Spain.Ferrer Gisbert, CM.; Ferran Gozalvez, JJ.; Redón Santafé, M.; Ferrer-Gisbert, P.; Sánchez-Romero, F.; Torregrosa Soler, JB. (2013). A new photovoltaic floating cover system for water reservoirs. Renewable Energy. (60):63-70. doi:10.1016/j.renene.2013.04.007S63706

Evaluación retroactiva mediante uso de pruebas objetivas tipo test

[EN] The evaluation by open written exam, traditionally used, it has been reconverted to test type exam. These tests have allowed a better knowledge of the acquisition of the fundamental concepts of the subject, in addition to allowing objectively its correction. The realization of this type of exams previously to parts of the subject where practical concepts are based on theoretical concepts,it has allowed a better approach to the contents and a feedback based on the results and perception of the teaching staff[ES] La evaluación mediante prueba escrita de tipo abierta, utilizada tradicionalmente, ha sido reconvertida a pruebas tipo test. Estas pruebas han permitido un mejor conocimiento de la adquisición de los conceptos fundamentales de la asignatura, además de permitir de manera objetiva su corrección. La realización de este tipo de pruebas previamente a partes de la asignatura donde se utilizan conceptos prácticos basados en conceptos teóricos necesarios, ha permitido un mejor enfoque de los contenidos y una retroalimentación basada en los resultados y percepción del profesorado.Sánchez Romero, FJ.; Ferrer Gisbert, CM.; Redón Santafé, M.; Torregrosa Soler, JB.; Ferran Gozalvez, JJ. (2019). Evaluación retroactiva mediante uso de pruebas objetivas tipo test. En IN-RED 2019. V Congreso de Innovación Educativa y Docencia en Red. Editorial Universitat Politècnica de València. 833-838. https://doi.org/10.4995/INRED2019.2019.10452OCS83383

Interlocking Modular Insulation Panels Manufactured with Mediterranean Pinewood and Cork

[EN] Economic profitability of harvested softwood in Southwestern Europe is limited for low quality logs. Some social and environmental consequences of low incomes of rural activities are rural depopulation and accumulation of biomass in unmanaged forests. The energy efficiency of buildings could be improved as construction material employing local bioresources that are currently used to manufacture products of low added value. Here, the IMIP project (Innovative Eco-Construction System Based on Interlocking Modular Insulation Wood & Cork-Based Panels) aimed to support the change towards a low carbon economy using bioproducts (pinewood and cork) for smart, sustainable, and inclusive growth with a special focus on the public construction sector is presented. The main objective of the IMIP project is to design, validate and implement an innovative ecological construction system based on natural biological materials to improve energy efficiency in public buildings from the construction, use and demolition phases. The project also develops a tool to professionals from the construction sector (architects and engineers) and researchers to assess the carbon footprint of buildings. The products of the project have the ambition to improve the economic, social and environmental situation of rural areas of Southwestern Europe.This research was funded by the Interreg SUDOE program as part of the European Regional Development Found (ERDF), grant number SOE3/P3/E0963.Brunet-Navarro, P.; Gilabert Sanz, S.; Monleón Doménech, M.; Redón-Santafé, M.; Hermoso, E.; Sánchez-González, M.; Luengo, E.... (2020). Interlocking Modular Insulation Panels Manufactured with Mediterranean Pinewood and Cork. Environmental Sciences Proceedings. 3(1):1-4. https://doi.org/10.3390/IECF2020-08072S143

Resistencia al fuego de pórticos simples de acero a dos aguas

[ES] El método habitual de análisis en situación de incendio consiste en el cálculo simplificado de barras aisladas. Es conservador al aplicarse a estructuras con capacidad de redistribuir esfuerzos. Se desconoce el tipo de fallo que afecta a la seguridad de las personas y extensión del fuego. Se utiliza el análisis avanzado para obtener el comportamiento a fuego de un pórtico simple a dos aguas de acero conforme a la normativa española. Se establece una metodología mediante un programa de cálculo estructural de propósito general (SAP2000), con un análisis dinámico no lineal del material (plástico) y geométrico (P-Delta y grandes desplazamientos), y propiedades mecánicas y térmicas dependientes de la temperatura. Se analizan los diferentes tipos de colapso. Se efectúan estudios paramétricos sobre la influencia de la rigidez de la base, protección de los soportes y cargas actuantes. Este cálculo puede permitir justificar mayores tiempos de resistencia al fuego que el análisis simplificado de barras.[EN] The standard procedure of structural fire design is based on the simplified analysis of single members. This method leads to conservative results in the case of structures able to redistribution of forces. The failure mechanism affecting both life safety and fire propagation is unknown. This work proposes a methodology for the advanced fire calculation of single pitched-roof portal frame for an agroindustrial building according to the Spanish Specifications with the structural software SAP2000. A non-linear dynamic and plastic, geometric (P-Delta and large-displacements) calculation method has been developed. The different failure mechanisms and their influence are studied in terms of fire time resistance, human hazard and good safety. Also, parametric analyses were conducted: load level, rotational stiffness of the base and finally, support fire protection.Ferran Gozalvez, JJ.; Ferrer Gisbert, CM.; Redón-Santafé, M.; Sánchez-Romero, F.; Torregrosa Soler, JB. (2017). Fire resistance of single pitched-roof steel portal frame. Informes de la Construcción. 69(545):1-11. doi:10.3989/ic.15.089S11169545Kretzberg, J., Kretschmer, F., & Marin-Burgin, A. (2007). Effects of multiple spike-initiation zones in touch sensory cells of the leech. Neurocomputing, 70(10-12), 1645-1651. doi:10.1016/j.neucom.2006.10.04

Durability of reinforced PVC-P geomembranes installed in reservoirs in eastern Spain

[EN] The aim of this paper is to study the durability of polyvinyl chloride (PVC-P) geomembranes reinforced with a synthetic fabric in hydraulic works in the Spanish Mediterranean basin. Therefore, a set of six geomembranes installed in irrigation reservoirs for 18¿31 years were analysed. The initial characteristics of the geomembranes were determined to verify fulfilment of the Spanish regulations in force at the time. The characteristics were then assessed, and the results were interpreted with reference to the loss of plasticisers, tensile characteristics, foldability at low temperatures, dynamic impact resistance, puncture resistance, seam strength, reflected optical microscopy (ROM) and scanning electron microscopy (SEM). Additionally, the identification of the plasticisers in the geomembranes involved Fourier transform infrared spectroscopy (FTIR), gas chromatography (GC) and mass spectrometry (MS) tests. For the analysed samples, the loss of plasticisers was significant, ranging from 71.0% to 84.3%. However, the tensile strength results indicated current, regular waterproof working performances in the reservoirs. The results suggest that the durability of PVC-P geomembranes is a function of the loss of plasticisers and the state of the synthetic reinforced fibres.Blanco, M.; Touze-Foltz, N.; Pérez-Sánchez, M.; Redón-Santafé, M.; Sánchez-Romero, F.; Torregrosa Soler, JB.; Zapata Raboso, FA. (2018). Durability of reinforced PVC-P geomembranes installed in reservoirs in eastern Spain. Geosynthetics International. 25(1):85-97. https://doi.org/10.1680/jgein.17.00035S859725

Reflections on the elaboration and implementation of emergency plans in agricultural water reservoirs

[SPA] Las balsas de tierra impermeabilizadas con geomembranas son obras muy seguras, tanto por la tipología constructiva empleada, como por su tipo de explotación, tal y como demuestra la experiencia y la escasez de incidencias. En cualquier caso, se debe ser consciente que cualquier infraestructura puede colapsar y causar daños, y en el peor de los casos la pérdida de vidas humanas. Aunque la probabilidad de colapso nula no existe, es obligación tanto de los usuarios, técnicos implicados el intentar conseguirla. El desarrollo de las sociedades exige mayores niveles de seguridad, y en este sentido tanto para las balsas de tierra como para cualquier otro tipo de infraestructura, las exigencias en seguridad cada vez son mayores. La seguridad en las balsas de tierra viene determinada por tres pilares fundamentales que son: 1. Criterios de proyecto y control durante la ejecución, en ciertos puntos críticos. 2. Mantenimiento de la seguridad a lo largo del tiempo, lo que requiere de unos planes eficaces de Vigilancia y Mantenimiento, dentro de unas normas de Explotación, acordes con las entidades titulares que las tienen que implementar. 3. En el peor de los casos, la infraestructura puede fallar, por lo que interesa analizar cuáles serían sus consecuencias y hacerlo con el suficiente detalle para que puedan adoptarse medidas eficaces que aminores, e incluso anulen los daños, y en especial de vidas humanas. Esta preocupación por la seguridad en las balsas se vio establecida con la inclusión de las balsas en el Real Decreto 9/2008. Una mala concepción de la seguridad en balsas ha querido trasladar a estas infraestructuras, los criterios y planteamientos de las presas, lo cual ha provocado una gran confusión, tanto administrativa como técnica, e incluso un rechazo del sector a la exigencia del establecimiento de un marco normativo para este tipo de infraestructuras. En la presente ponencia se establecen una serie de reflexiones sobre los contenidos de los Planes de Emergencia, estableciendo la diferencia entre su aplicación a presas y balsas, las implicaciones sociales que pueden derivarse de los mismos, así como cuáles deben ser los criterios a seguir para incrementar la seguridad real de las balsas. [ENG] Agricultural Water Reservoirs waterproofed with geomembranes are very safe works, both because of the construction technology used and the type of operation, as shown by experience and the scarcity of incidents. In any case, one must be aware that any infrastructure can collapse and cause damage, and in the worst case, the loss of human lives. Although the probability of zero collapse does not exist, it is the obligation of both the users and the technicians involved to try to achieve it. The development of societies demands higher levels of safety, and in this sense, both for Agricultural Water Reservoirs and for any other type of infrastructure, the safety requirements are increasingly higher. Safety in Agricultural Water Reservoir is determined by three fundamental pillars: 1. Criteria for design and control during execution, at certain critical points. 2. Maintenance of safety over time, which requires effective surveillance and maintenance plans, within the framework of operating standards, in accordance with the entities that have to implement them. 3. In the worst case scenario, the infrastructure may fail, so it is important to analyze the consequences and to do so in sufficient detail so that effective measures can be adopted to reduce or even eliminate the damage, especially in terms of human lives. This concern for raft safety was established with the inclusion of rafts in Royal Decree 9/2008. A bad conception of safety in Agricultural Water Reservoir has wanted to transfer to these infrastructures, the criteria and approaches of dams, which has caused great confusion, both administrative and technical, and even a rejection of the sector to the demand for the establishment of a regulatory framework for this type of infrastructure. This paper sets out a series of reflections on the contents of the Emergency Plans, establishing the difference between their application to dams and agricultural reservoirs, the social implications that may derive from them, as well as the criteria to be followed in order to increase the real safety of reservoirs