Effect of particle shape and fragmentation on the response of particle dampers

A particle damper (PD) is a device that can attenuate mechanical vibrations thanks to the dissipative collisions between grains contained in a cavity attached to the vibrating structure. It has been recently suggested that, under working conditions in which the damping is optimal, the PD has a universal response in the sense that the specific dissipative properties of the grains cease to be important for the design of the device. We present evidence from simulations of PDs containing grains of different sizes, shapes and restitution coefficients, that the universal response is also valid when fragmentation of the grains occurs (generally due to intensive operation of the PD). In contrast, the welding of grains (caused by operation under high temperatures) can take the PD out of the universal response and deteriorate the attenuation. Interestingly, we observed that even at working conditions off the optimal damping, the shape of the grains remains unimportant for the response of the PD.Fil: Sánchez, Martín. Universidad Tecnológica Nacional; ArgentinaFil: Carlevaro, Carlos Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física de Líquidos y Sistemas Biológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física de Líquidos y Sistemas Biológicos; ArgentinaFil: Pugnaloni, Luis Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional; Argentin

Paleogene evolution of the External Rif Zone (Morocco) and comparison with other western Tethyan margins

The Paleogene evolution of theNWmargin of the African Plate (Western External Rif Zone)was studied by means of multidisciplinary analyses of twenty-one stratigraphic logs, including tectofacies recognition, petro-mineralogical results, and thicknesses analysis. Four stratigraphic intervals were recognized separated by three unconformities coarsely aligned with the Cretaceous–Paleogene, Eocene–Oligocene and Oligocene–Miocene boundaries, respectively. Tectofacies appear from the late Ypresian being more frequents from the Oligocene as the tectonic activity increases. The petrology of detrital suites indicates recycled orogen-derived sediments, with quartz supplied from metamorphic rocks of the Atlas orogen and/or the African craton. On the basis ofMesozoic claymineral assemblages reported in the literature, the clay mineralogy of mudstones suggests upper Jurassic to upper Cretaceous terrains from the Internal Intrarif as the main source area of the Paleocene–Eocene successions, with sediment provenance reversion during the Oligocene and additional contribution of Paleocene to lower Eocene suites. The different displacement capability of the identified aluminic-magnesic claymineralogy enabled to deduce the relative proximity of the source area. These findings point out a complex sedimentary evolution characterized by a mixture of different lithotypes dating back to upper Jurassic. X-ray parameters helped to identify evidences of synsedimentary tectonics overprinting the inheritedmineralogy during some periods with weak burial diagenesis at most. During the Paleogene a foreland basin is formed mainly in theMesorif and Prerif sub-domains. This foredeep was represented by two ‘sub-geosynclines’ separated by a relative bulge located in the ExternalMesorif. The Internal Intrarif could represent the relative orogenic front, advancing on the External Intrarif. The Eocene forebulge was located in the Ridges Domain, while the Gharb Basin was the backbulge of the system. During the Oligocene the depocentral area migrated southward and a homogeneization of thicknesses took also place in thewholemargin. In this newconfiguration, the foredeep would be located in the External Mesorif (previously a relative bulge) while the Ridges Domain and the Gharb Basin continued to act as the systemforebulge and backbulge, respectively. A comparisonwith the Paleogene evolution of otherwestern Tethys externalmargins (Betic Chain, Tunisian Tell, SicilianMaghrebids, and Apennines) has revealed more similarities than differences. The effects of the Eo-Alpine tectonics are recognized everywhere even if they decrease both from N to S, and fromWto E in the different considered margins. The evolution of the compared margins shows a common pre-foredeed (Paleocene-Eocene) and beginning of foredeep (Oligocene) stages in the foreland basins.PID2020-114381GB-I00 research project (Spanish Ministry of Education and Science)

Short simulation activity to improve the competences in the Fluid-mechanical Engineering classroom using Solidworks ® Flow Simulation

7 p.In this paper, a short simulation activity based on Computational Fluid Dynamics (CFD) is raised in the context of the Mechanical Engineering Bachelor degree as an effective support to the theoretical lessons, in order to improve the competences of the Fluid-Mechanical course. The activity provides both visual and numerical information that the student must compare critically with respect the results obtained analytically, using the equations explained in the theoretical classroom. The activity is designed so that it can be integrated quickly (due to the shortage of times in the academic calendars). In this manner its total completion does not exceed four hours of simulation class. This is achieved by optimizing the resources, proposing meshing and simulation strategies that consume little computational time and using the package Solidworks® Flow Simulation, that takes advantage of the geometry parametrically modelled with the software itself to automatically establish the computational domain of the fluid for the based-on CFD analysis, saving excessive preparation times and long computational process.S

Necesidad de la provisión de un servicio de intérpretes en los hospitales.

Las migraciones y la movilidad poblacional han hecho surgir la necesidad de contar con servicios de interpretación en los hospitales, para enfrentarse a situaciones en que médico y paciente no usan el mismo idioma. El intérprete profesional ofrece claras ventajas sobre otras formas habituales de interpretación, como la colaboración de familiares bilingües o intérpretes voluntarios no cualificados, aunque razones de índole económica enfrían el entusiasmo de las administraciones públicas para su efectiva dotación. Por otra parte, las dificultades que conlleva disponer de intérprete en cualquier momento y lugar son satisfactoriamente resueltas por los servicios de interpretación telefónica

CRISPR-ERA for switching off (onco)genes

[EN]Genome editing nucleases like the popular CRISPR/Cas9 allow generate knock - out cell lines and nulls zygotes by inducing site - specific DSB within a genome. In most cases, when a DNA template is not present, the DSB is repaired by non - homologous end joining (NHEJ) resulting in small nucleotide insertions or deletions that can be used to construct knockout alleles. However, for se veral reasons, these mutations do not produce the desired null result in all cases, generating a similar protein with functional activity. That undesirable effect could limit the therapeutic efficiency of gene therapy strategies focused on abrogating oncog ene expression by CRISPR/Cas9 and should be taken in account. This chapter reviews the irruption of CRISPR technology for gene silencing and its application in gene therapy

Evaluación técnico económica de centrales solares de torre con receptores de aire presurizado integrados en turbinas de gas.

En la tesis participan empresas, por tanto, existe acuerdo de confidencialidad que afecta a los capítulos 3,5 y 6.En la tesis participan empresas y existe un acuerdo de confidencialidad que afecta a los capítulos 3,5 y 6El objetivo principal de la tesis es el análisis técnico y económico de centrales solares de tecnología de torre con receptores de aire presurizado integrados en turbinas de gas. Este tema ha sido previamente estudiado por diversos autores pero los modelos técnicos y económicos utilizados fueron excesivamente simplificados por lo que se consideró necesario un análisis pormenorizado. Con este propósito se realizó un análisis técnico modelando la planta termosolar en diferentes subsistemas -campo solar, receptor solar y turbina de gas- con el acoplamiento de un receptor de aire presurizado en la cámara de combustión. La herramienta desarrollada permite realizar las estimaciones anuales de producción en base horaria en función de las variables principales de planta (área de apertura del campo solar, potencia eléctrica, altura de torre, etc.) y localización geográfica. Paralelamente, se desarrolló un modelo económico que evalúa los costes del proyecto para distintas alternativas de negocio en todas las fases del proyecto (promoción, construcción y operación) parametrizando los equipos en función de las variables principales de planta. Los resultados anteriores se integran en un modelo financiero que considera el ciclo de vida completo del proyecto: costes de desarrollo, construcción, operación y mantenimiento y los costes de desmantelamiento. La obtención de resultados y análisis de viabilidad se obtiene sobre un espacio de diseño que cubre el rango de operación previsto para la tecnología. El análisis se realiza para dos perfiles de operación distintos, operación carga base y operación diurna. El trabajo incluye un análisis de sensibilidad del funcionamiento y variables económico-financieras en función de las posibles configuraciones, coste de combustible, localizaciones geográficas y tamaño de los equipos. En último lugar, se listan las conclusiones, se describen las debilidades y fortalezas de este tipo de centrales y se enumeran los requisitos técnicos de los equipos con el objetivo de definir las líneas de investigación necesarias para convertir esta tecnología en una opción comercialmente ejecutable. Como principales resultados, el trabajo propone una configuración de los equipos así como unas características del motor capaces de acomodarse a las irregularidades del recurso solar. El desarrollo de una “turbina solarizada” y de tecnologías de receptor solar adecuadas es imprescindible para avanzar en la tecnología. Los resultados técnico-económicos arrojan que en un escenario de alto coste de combustible y operación diurna de la central proporcionan resultados competitivos frente a otras tecnologías convencionales

Short CFD simulation activities in the context of fluid-mechanical learning in a multidisciplinary student body

17 p.Simulation activities are a useful tool to improve competence in industrial engineering bachelors. Specifically, fluid simulation allows students to acquire important skills to strengthen their theoretical knowledge and improve their future professional career. However, these tools usually require long training times and they are usually not available in the subjects of B.Sc. degrees. In this article, a new methodology based on short lessons is raised and evaluated in the fluid-mechanical subject for students enrolled in three different bachelor degree groups: B.Sc. in Mechanical Engineering, B.Sc. in Electrical Engineering and B.Sc. in Electronic and Automatic Engineering. Statistical results show a good acceptance in terms of usability, learning, motivation, thinking over, satisfaction and scalability. Additionally, a machine-learning based approach was applied to find group peculiarities and differences among them in order to identify the need for further personalization of the learning activity.S

Effect of particle shape and fragmentation on the response of particle dampers

A particle damper (PD) is a device that can attenuate mechanical vibrations thanks to the dissipative collisions between grains contained in a cavity attached to the vibrating structure. It has been recently suggested that, under working conditions in which the damping is optimal, the PD has a universal response in the sense that the specific dissipative properties of the grains cease to be important for the design of the device. We present evidence from simulations of PDs containing grains of different sizes, shapes and restitution coefficients, that the universal response is also valid when fragmentation of the grains occurs (generally due to intensive operation of the PD). In contrast, the welding of grains (caused by operation under high temperatures) can take the PD out of the universal response and deteriorate the attenuation. Interestingly, we observed that even at working conditions off the optimal damping, the shape of the grains remains unimportant for the response of the PD.Instituto de Física de Líquidos y Sistemas Biológico

The Messinian record of the outcropping marginal Alborán basin deposits: significance and implications

The Messinian record of marginal Alboran basins, such as the Sorbas Basin in southern Spain, consists of a shallow-marine succession with intercalated evaporites. The pre-evaporite sequence comprises a bryozoan-bivalve, temperate-carbonate unit overlain by tropical carbonates. The latter, in turn, consists of two superimposed units: a bioherm unit with coral (Porites, Tarbellastraea, and Siderastraea) and algal (Halimeda) mounds, and a coral (Porites)-stromatolite fringing reef unit. Climatic fluctuations in the Alboran area, linked to the Neogene glacial-interglacial oscillations, are thought to be responsible for the change from temperate to tropical conditions. Evaporites are mainly selenite gypsum deposits. The first post-evaporite unit is a mixed siliciclastic-carbonate marginal deposit, with small coral (Porites) patches and huge microbial (stromatolite and thrombolite) domes, changing basinward to silts and marls containing planktonic foraminifers. An incised erosion surface was scoured on top of the pre-evaporitic fringing reef unit. This erosion surface formed during drawdown and desiccation of the Mediterranean Sea, when huge masses of salt were deposited in its center. Deposition of gypsum at the very margin of the Alboran Sea took place later in small, barred, satellite perched basins. In these silled basins marine incursions became more and more frequent until a full connection with the Mediterranean Sea was established by the end of the Messinian. Reflooding was completed during the Messinian, as demonstrated by the marine marls with planktonic foraminifers found on top of the evaporites. This situation is comparable to that of the western Mediterranean (DSDP Site 372; ODP Site 975), where the upper evaporites are directly overlain by Messinian marls with planktonic foraminifers. During the initial stages of marine recolonization, microbes coexisted with, but outcompeted, the normal marine biota. This resulted in the widespread proliferation of microbial carbonates (stromatolites and thrombolites).This work was supported by DGICYT (Spain) Project PB93-1113 and by “Fundación Ramón Areces” Project: “Cambios climáticos en el sur de España durante el Neógeno.