Effect of Processed Volcanic Ash as Active Mineral Addition for Cement Manufacture

In the last quarter of 2021, there was a very significant eruption of the Cumbre Vieja volcano on the island of La Palma, belonging to the Canary Islands, Spain. It generated a large amount of pyroclastic volcanic materials, which must be studied for their possible applicability. This work studies the properties and applicability of the lava and volcanic ash generated in this process. The need for reconstruction of the areas of the island that suffered from this environmental catastrophe is considered in this study from the point of view of the valuation of the waste generated. For this purpose, the possibility of using the fine fraction of ashes and lava as a supplementary cement material (SCM) in the manufacture of cement is investigated. The volcanic material showed a chemical composition and atomic structure suitable for replacing clinker in the manufacture of Portland cement. In this study, the cementing and pozzolanic reaction characteristics of unprocessed volcanic materials and those processed by crushing procedures are analysed. To evaluate the cementitious potential by analysing the mechanical behaviour, a comparison with other types of mineral additions (fly ash, silica fume, and limestone filler) commonly used in cement manufacture or previously studied was carried out. The results of this study show that volcanic materials are feasible to be used in the manufacture of cement, with up to a 22% increase in pozzolanicity from 28 to 90 days, showing the high potential as a long-term supplementary cementitious material in cement manufacturing, though it is necessary to carry out crushing processes that improve their pozzolanic behaviour

La Chancellerie Royale de Grenade et le crime : preuve d’expert et preuve de l’exécution d’une femme enceinte à Torredonjimeno (Jaén) en 1598

En el presente artículo se analiza y edita un expediente conservado en la Real Chancillería de Granada que contiene la información y probanza que el receptor Francisco García de Villamayor realizó en la villa de Torredonjimeno (Jaén) en el año de 1598, a instancia de los Alcaldes del Crimen de la Audiencia granadina, con motivo del ajusticiamiento de mujer preñada y que conocía esa Corte por vía de atentado. El documento, que recoge como prueba pericial el levantamiento del cadáver y la autopsia de la ejecutada, resulta una peculiar fuente de conocimiento tanto para la historia del proceso, como para la historia institucional, la historia de las mujeres y la historia de la medicina.This article will analyse and edit a file kept at the Royal Chancellery of Granada. It contains the information and witness proof made by scrivener Francisco García de Villamayor in the town of Torredonjimeno (Jaén) in the year of 1598, at the request of the Criminal Justices of the Granada Audience, on the occasion of the execution of a pregnant woman, and which was heard by that Court through appellation. The document, which shows the lifting of the corpse of the executed woman and the autopsy as expert evidence, is a rare source of knowledge for the history of prosecution, institutional history, history of women and history of medicine.Cet article analyse et édite un dossier conservé à la Chancellerie Royale de Grenade qui contient les informations et les preuves sur le séquestre de Francisco García de Villamayor dans la ville de Torredonjimeno (Jaén) en 1598, à la demande des maires du Crime de la Haute Cour de Grenade, à l’occasion de l’exécution d’une femme enceinte et qui a connu cette Cour par voie d’attentat. Le document, qui recueille comme preuve d’expert le retrait du cadavre et l’autopsie de l’exécuté, est une source particulière de connaissances à la fois pour l’histoire du processus, l’histoire institutionnelle, l’histoire des femmes et l’histoire de la médecine. Mots clé: Torredonjimeno (Jaén); maire ordinaire; simple et mixte imperio; Chancellerie Royale de Grenade; maires du crime; témoignage d’expert; autopsie

Alkali-Activated Stainless Steel Slag as a Cementitious Material in the Manufacture of Self-Compacting Concrete

This work develops the manufacture of self-compacting concrete (SCC) with 50% cement reduction. As an alternative binder to cement, the viability of using an alkali-activated combination of stainless steel slag (SSS) and fly ash (FA) has been demonstrated. SSS was processed applying three different treatments. Binders were manufactured mixing 35% SSS with 65% FA, as precursors, and a hydroxide activating solution. This binder was replaced by the 50% cement for the manufacture of SCC. The results obtained show good mechanical properties and durability. The study shows a reduction in the use of cement in the manufacture of SCC reusing two wastes

Eco-Efficient Cement-Based Materials Using Biomass Bottom Ash: A Review

In recent years the use of biomass for electricity generation in thermal and cogeneration plants has increased worldwide because it is an environmentally clean fuel whose impact measured in greenhouse gas emissions is practically zero. However, biomass bottom ash, a waste produced during combustion, has also increased considerably, which has both a negative economic and environmental impact, due to landfill transport and management of this by-product. Although biomass bottom ash has potential characteristics for application in the manufacture of construction materials, its full-scale application is difficult because of the wide range in physicochemical properties, depending on the type of biomass burned, such as wood residue, olive waste, waste paper sludge, cocoa shell, etc., and the type of combustion process in the plant. This study reviews the influence on the physicochemical properties, mechanical behavior, and durability of different cement-based materials, such as mortars, concrete, and cement-treated granular material, manufactured from biomass bottom ash. The previous studies demonstrate the feasibility of substituting natural materials for biomass bottom ash in cement-based materials, presenting adequate mechanical behavior and durability properties to comply with the required technical specifications in different building materials

Determinando la relación entre fiscal stress y externalización en tiempos de crisis. Evidencia empírica sobre el servicio de recogida de residuos

Una mala situación financiera es un factor explicativo recurrente en la literatura que estudia el fenómeno de la externalización de servicios públicos. Esta relación puede haberse intensificado en los últimos años debido a la crisis económica y financiera mundial. Para analizar la relación existente entre 'fiscal stress', crisis global y la externalización, junto con otros factores políticos y socioeconómicos, nos centramos en este trabajo en uno de los servicios que mayor coste y complejidad presenta para los ayuntamientos, el servicio de recogida de basuras. Para ello, planteamos un modelo probit de datos de panel para el periodo 2002-2010. Los resultados obtenidos indican que varias variables de la condición financiera influyen en los procesos de externalización del servicio de residuos, junto con las variables políticas y socioeconómicas. Por último, el período de crisis global 2008-2010 influye positiva y significativamente a la hora de externalizar el servicio

Diseño del plan estratégico de seguridad de la información (PESI) para una entidad hipotética; según vulnerabilidades identificadas en ambientes de pruebas controlados.

El servidor web de una entidad hipotética ha sido víctima de ataques Defacement y Eternal Blue por parte de Black Hackers, en las sedes ubicadas en las ciudades de Bogotá y Cali respectivamente. Dado esto y al proceso de expansión que inician en el presente año, la alta dirección ha decidido contratar a un experto en seguridad informática con el fin de realizar las pruebas de vulnerabilidad que ayuden a descifrar el método de intrusión utilizado, y cada uno de los pasos que siguieron para lograrlo. Para ello se utilizarán herramientas de análisis de seguridad como los Nmap, Metasploit y OpenVas encontradas en la distribución Kali Linux. Al final del análisis se entregará un informe detallado del procedimiento llevado a cabo y de un Plan Estratégico de Seguridad de la Información a implementar en la organización con el fin de solventar los problemas de seguridad en los sistemas de información y prevenir problemas futuros, con el fin de garantizar la seguridad en la prestación de los servicios a sus clientes.The web server of a hypothetical entity has been the victim of Defacement attacks and Eternal Blue by Black Hackers, in the headquarters located in the cities of Bogotá and Cali respectively. Given this and the expansion process that begins in this year, the senior management has decided to hire a security expert computing in order to carry out vulnerability tests that could help to decipher the intrusion method used, and each of the steps they followed to make it succeed to acomplish this , security analysis tools will be used such as Nmap, Metasploit and OpenVas found in the Kali Linux distribution. At the end of analysis, a detailed report of the procedure carried out will be given and also an Strategic Plan for Information Security to implement in the organization in order to solve the security problems in the information systems and to prevent future problems, in order to guarantee security in the provision of services to your customers

A Two-Level Dynamic Chrono-Scheduling Algorithm

We propose a dynamic instruction scheduler that does not need any kind of wakeup logic, as all the instructions are “programmed” on issue stage to be executed in pre-calculated cycles. The scheduler is composed of two similar levels, each one composed of simple “stations”, where the timing information is recorded. The first level is aimed to the group of instructions whose timing information cannot be calculated at issue (for example, those instructions whose latency is not predictable). The second level contains simple “stations” for the instructions whose execution and write back cycle have been already calculated. The key idea of this scheduler is to extract and record all possible information about the future execution of an instruction during its issue, so as not to look for this information again and again during wait stages at the reservation stations. Another additional advantage is that time critical parts can be identified as instruction timing information is available, so high speed and frequency logic can be used only in these parts, while the rest of the scheduler can work at lower frequencies, therefore consuming much less power. The lack of wakeup and CAM (Content Addressable Memory) means that power consumption and latencies would be presumably reduced, frequency would probably be made higher, while CPI (clock Cycles Per Instruction) would remain approximately the same.Ministerio de Educación y Ciencia TIN2006-15617- C03-03Junta de Andalucía P06-TIC-0229

Feasibility of Using Nanosilanes in a New Hybrid Stabilised Soil Solution in Rural and Low-Volume Roads

The application of new materials for soil stabilisation is a growing field of study in recent years. In this work, the effect of two types of silica-based nanomaterials combined with binders (quicklime and cement) are studied to stabilise soils and form structural layers for rural and low volume roads. The physical and chemical properties of the materials have been determined, as well as the mechanical behaviour of the stabilised soil. Three hybrid stabilised soil sections have been designed using a multilayer elastic model, executed at full scale and measuring the evolution of their properties in the medium to short term. The results show that the application of silica-based nanomaterials and two types of binders on the tread layers provide high structural stability and good behaviour of the sections

Estimación de Precios de Bitcoin mediante Regresión Lineal Múltiple y Redes Neuronales

Various studies have focused on estimating the price of cryptocurrencies using time series models and static variables. This study focuses on Bitcoin price prediction, using a model that combines multiple linear regression and neural networks. This approach makes it possible to identify the factors that influence Bitcoin volatility and, through a dynamic selection of variables, to constantly detect the most relevant set of characteristics for prediction. Likewise, the amount of data is optimized to improve precision and avoid overuse of historical information. The combination of these techniques captures underlying patterns and trends, increasing the reliability of predictions, with an accuracy of 88%. However, it is crucial to consider the need for continuous evaluations to adapt to changing market conditions. This approach provides a more accurate tool for making informed decisions in a highly volatile market.Diversos estudios se han enfocado en estimar el precio de las criptomonedas utilizando modelos de series de tiempo y variables estáticas. Este estudio se centra en la predicción del precio de Bitcoin, utilizando un modelo que combina la regresión lineal múltiple y las redes neuronales. Este enfoque permite identificar los factores que influyen en la volatilidad de Bitcoin y, mediante una selección dinámica de variables, detectar constantemente el conjunto de características más relevante para la predicción. Asimismo, se optimiza la cantidad de datos para mejorar la precisión y evitar la sobreutilización de información histórica. La combinación de estas técnicas permitió capturar patrones y tendencias subyacentes, aumentando la confiabilidad de las predicciones, con una precisión del 88%. Sin embargo, es crucial considerar la necesidad de evaluaciones continuas para adaptarse a las cambiantes condiciones del mercado. Este enfoque brinda una herramienta más precisa para tomar decisiones informadas en un mercado altamente volátil.

Estimación de Precios de Bitcoin mediante Regresión Lineal Múltiple y Redes Neuronales

Diversos estudios se han enfocado en estimar el precio de las criptomonedas utilizando modelos de series de tiempo y variables estáticas. Este estudio se centra en la predicción del precio de Bitcoin, utilizando un modelo que combina la regresión lineal múltiple y las redes neuronales. Este enfoque permite identificar los factores que influyen en la volatilidad de Bitcoin y, mediante una selección dinámica de variables, detectar constantemente el conjunto de características más relevante para la predicción. Asimismo, se optimiza la cantidad de datos para mejorar la precisión y evitar la sobreutilización de información histórica. La combinación de estas técnicas permitió capturar patrones y tendencias subyacentes, aumentando la confiabilidad de las predicciones, con una precisión del 88%. Sin embargo, es crucial considerar la necesidad de evaluaciones continuas para adaptarse a las cambiantes condiciones del mercado. Este enfoque brinda una herramienta más precisa para tomar decisiones informadas en un mercado altamente volátil.