Los plásticos en la construcción

Not availableAunque la industria de los plásticos no nació hasta el siglo XIX, puede decirse que los romanos utilizaron dichos materiales, pues hoy noticias del uso de la caseína para fijar pigmentos en los papiros

Instalación experimental para ensayos de clinkerización

Entre la escala de laboratorio y la de la planta piloto semi-industrial, instalada en el Instituto, se hacía necesaria una intermedia, que produjera material en cantidad suficiente para los ensayos oportunos, sin que significara un alto consumo de materia prima, combustible, tiempo, etc

Vindicación de la opinión y conducta política de Francisco Arredondo ... contra los autores de dos anónimos.

Copia Digital. España : Ministerio de Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 2022- L2Texto fechado en 1841

Optimization of the operation of a flywheel to support stability and reduce generation costs using a Multi-Contingency TSCOPF with nonlinear loads

Multi-Contingency Transient Stability Constrained Optimal Power Flow (MC-TSCOPF) models optimize the economic dispatch of power systems while ensuring their stability after a series of reference incidents. This paper proposes a MC-TSCOPF model that represents the power balance at each node of the system and at each sample time. The proposed model includes non-linear loads, synchronous generators, a windfarm, and a Flywheel Energy Storage system (FESS). The model is written on GAMS and solved using a standard Interior Point algorithm. This study focuses on the Fuerteventura-Lanzarote insular grid in Spain, where stability problems and load shedding cause high additional costs due to the low inertia of the system. A FESS has been recently installed in the system to improve its stability, taking advantage of its high-power capacity and rapid response. The proposed TSCOPF model has been applied to optimize the operation of the FESS to support stability in the event of a contingency. The results of the study show that 1) a proper model of non-linear loads is essential in TSCOPF studies; 2) the proposed MC-TSCOPF provides a tool for minimizing the generation costs while ensuring transient and frequency stability; and 3) it is possible to further reduce the generation costs by using the proposed model to calculate an optimal dynamic response of the FESS.Publicad

Optimal Curtailment of Non-Synchronous Renewable Generation on the Island of Tenerife Considering Steady State and Transient Stability Constraints

The increasing penetration of non-synchronous, renewable energy in modern power systems displaces synchronous generation and affects transient stability. This is just one of the factors that has led to preventive curtailment of renewable energy sources in an increasing number of electrical grids. Transient stability constrained optimal power flow (OPF) techniques provide a tool to optimize the dispatch of power systems while ensuring a secure operation. This work proposes a transient stability-constrained OPF model that includes non-synchronous generation with fault ride-through capability and reactive support during voltage dips. The model is applied it to the IEEE 39 Bus benchmark test case and to the power system of the Spanish island of Tenerife, and solved using the open-source library IPOPT that implements a primal-dual interior point algorithm. The solution of the model makes it possible to optimize the dispatch of conventional plants and the curtailment of non-synchronous generation, as well as to explore methods to reduce generation cost. Fault ride-through capability, synchronous inertia and fault clearing times are identified as useful tools to reduce the curtailment of non-synchronous generation, especially during periods of low load and high availability of renewable energy sources.The authors acknowledge the Ministry of Science and Technology of Spain (Project RESMART, ENE2013-48690-C2-1-R)

Tendencias en la tecnología del cemento y posibles innovaciones

Hace más de un año que empezamos a preparar estos coloquios. Pecaría de injusticia si mis primeras palabras no fueran para dedicar un cariñoso recuerdo a tres personas, a tres amigos queridos, involucrados en esta preparación que nos han abandonado en el transcurso de este año

Biological Efficacy of <em>Trichoderma</em> spp. and <em>Bacillus</em> spp. in the Management of Plant Diseases

This chapter will cover topics about the microbial antagonists Trichoderma spp. and Bacillus spp. from the perspective of use as potential biological control agents on plant diseases. Results obtained in the laboratory about from their isolation, microbial strain collections for both genera, taxonomic identification, antifungal activity in in vitro tests, obtained evaluation of the antifungal effect of secondary metabolites from microbial antagonists will be shown. Besides, results obtained from bioassays in the greenhouse and field are used as biopesticides in the control of diseases in fruit trees and vegetables and their effects on the promotion of plant growth and increased crop yield

Carcinoma broncogénico escamocelular con afectación pericárdica como única metástasis a distancia

Squamous cell carcinoma of the lung causes distant metastases, rarely to the heart, causing pericardial effusion with evolution to cardiac tamponade and even death. We present the case of a middle-aged man who came to the emergency room due to chest pain with an incidental finding of a lesion at the level of the right lower lobe (LID) on the chest X-ray, during his study a single cardiac metastasis was observed as the only one Clinical manifestation of pericardial effusion without hemodynamic affectation, pharmacological treatment was started due to the diagnosis of squamous cell carcinoma, known before the appearance of the effusion, and he was referred to Oncology for chemotherapy treatment with improvement of the same without the need for invasive techniques such as pericardiocentesis or pericardiectomy. With this case, we observe the rarity of the pericardial effusion caused by the only metastasis of the patient from a lung carcinoma and its evolution without invasive treatments.El carcinoma escamocelular de pulmón ocasiona metástasis a distancia, rara vez al corazón provocando derrame pericárdico con evolución a taponamiento cardíaco e incluso la muerte. Se presenta el caso de un varón de mediana edad que acudió a Urgencias por dolor torácico con hallazgo incidental de una lesión a nivel de lóbulo inferior derecho (LID) en la radiografía de tórax, durante su estudio se objetiva una metástasis única cardíaca y como única manifestación clínica derrame pericárdico sin afectación hemodinámica, se inició tratamiento farmacológico ante el diagnóstico de carcinoma escamocelular, conocido antes de la aparición del derrame, y fue derivado a Oncología para tratamiento quimioterápico con mejoría del mismo sin necesidad de técnicas invasivas como pericardiocentesis o pericardiectomía. Con este caso observamos la rareza del derrame pericárdico provocado por la única metástasis del paciente de un carcinoma de pulmón y la evolución del mismo sin tratamientos invasivos

Multi-contingency TSCOPF based on full-system simulation

Transient stability constrained optimal power flow (TSCOPF) is a non-linear optimisation problem used to perform economic dispatches while ensuring TS. This study proposes a multi-contingency TSCOPF model that retains the dynamics of all generators and includes a transient synchronous generator fourth-order dq-axis model. A program is developed that automatically reads the system data from standard files, builds the multiple-contingency TSCOPF model on a high-level modelling system and solves it using a non-heuristic interior point algorithm. This approach facilitates the application of the model to a variety of systems and scenarios. A TSC based on the speed deviation instead of the rotor angle is proposed. Results obtained on several standard systems are shown. The proposed method is applied to the northwest Spanish transmission system to obtain an optimised dispatch that ensures TS after any of a number of faults, and to assess the economic impact of fault-clearing times at different substations.The authors acknowledge the Ministry of Science and Technology of Spain (Project RESMART, ENE2013-48690-C2-1-R)

Evaluation of numerical methods for TSCOPF in a large interconnected system

Transient stability-constrained optimal power flow (TSCOPF) models comprehensively analyze the security and economic operation of power systems. However, they require a high computational effort and can suffer from convergence problems when applied to large systems. This study analyzes the performance of eleven numerical integration algorithms applied to ordinary differential equations that represent power system dynamics in a TSCOPF model. The analyzed algorithms cover a range of explicit and implicit methods, including the recently published semi-explicit and semi-implicit Adams-Bashforth-Moulton formulas, together with several initialization techniques. The integration methods are applied to a model of the Iberian Peninsula power system, and their performance is discussed in terms of convergence, accuracy, and computational effort. The results show that most implicit methods converge to the solution, even for large time steps. In particular, the Adams-Moulton method of order two and Simpson's rule, both initialized with RK4, outperform the trapezoidal rule, which is the default method in TSCOPF models.This work was supported by the Spanish Agencia Estatal de Investigación under Project PID2019-104449RB-I00 and Project AEI/10.13039/501100011033