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Analysis of meteoritic activity in the Vth-XVth centuries using an extended survey of European Medieval Sources

  • Martínez Uso, María José
  • Marco Castillo, Francisco J.
[EN] The distribution of meteors streams throughout a year from the 5th to the 15th century is investigated, based on a new compilation of meteor records in the diverse European Medieval sources. The records of meteor showers and storms in the chronicles of Korea, Japan, China and Arab have also been considered, and compare their appearance dates with those of showers obtained above, as well as with modern observations. We found that the three sets of data are in agreement with each other, the Perseids, Leonids, and Lyrids being best represented., Work of this paper was partially supported by the UJI-B2016-18, 161356 project.

Reduced computational cost prototype for street theft detection based on depth decrement in Convolutional Neural Network. Application to Command and Control Information Systems (C2IS) in the National Police of Colombia

  • Suarez-Paez, Julio Ernesto
  • Salcedo-González, Mayra Liliana
  • Esteve Domingo, Manuel
  • Gomez, J.A.|||0000-0002-4174-3762
  • Palau Salvador, Carlos Enrique
  • Pérez Llopis, Israel
[EN] This paper shows the implementation of a prototype of street theft detector using the deep learning technique R- CNN (Region-Based Convolutional Network), applied in the Command and Control Information System (C2IS) of National Police of Colombia, the prototype is implemented using three models of CNN (Convolutional Neural Network), AlexNet, VGG16 and VGG19 comparing their computational cost measuring the image processing time, according to the complexity (depth) of each model. Finally, we conclude which model has the lowest computational cost and is more useful for the case of the National Police of Colombia.

Enhancing the mechanical features of clay surfaces by the absorption of nano-SiO2 particles in aqueous media. Case of study on Bronze Age clay objects

  • Rayón, E.|||0000-0002-0653-2046
  • Arrieta, Marina Patricia
  • Pasies -Oviedo, Trinidad
  • López-Martínez, Juan|||0000-0001-6904-2282
  • Jorda Moret, Jose Luis|||0000-0002-0304-5680
[EN] Nanoparticles are known to be able to enhance the performance of low dense materials, achieving the small intergranular spaces to further interact with the matrix. In this work, a consolidation treatment of an ancient clay material is reported. It is based on the use of silica nanoparticles dispersed in an aqueous medium as a more sustainable approach than those currently used in the conservation field. The effective consolidation has been determined by ensuring an appropriate mechanical surface resistance using the nanoindentation technique as non-destructive measurements. Moreover, the ability of SiO(2 )nanoparticles to fill the microstructure is studied by scanning electron microscopy. As a case report, several low-strength clay fragments dated from the Bronze Age were surface treated with a commercial aqueous suspension of SiO2 nanoparticles that were analyzed by transmission electron microscopy (TEM) displaying dimensions of about 20 nm in diameter. Field Emission Electron Microscopy (FESEM) revealed that nanoparticles filled the inter-granular spaces of the clay, leading to a nanostructured material. The nanoindentation results showed an increase in surface resistance against scratching. Meanwhile, the nanohardness and elastic modulus increased 10 times (from 15 to 150 MPa) and 8 times (from 1 to 8 GPa), respectively due to the nano-SiO2 treatment, confirming the consolidation effect of the nanoparticles., Authors acknowledge the financial support of Spanish Ministry of Economy and Competitiveness, MAT2014-59242-C2-1-R. Authors also acknowledge the support of Helena Bonet, Director of the Prehistory Museum of Valencia and Ma Jesus de Pedro, conservator of this Museum, and to the Photographic Archive Department. M.P. Arrieta wishes to thank the financial support of MINECO for a Juan de la Cierva (FJCI-2014-20630) contract.

Relaciones entre Arquitectura y Estructura. Arquitectura estructural en Mies van der Rohe, Relationships between Architecture and Structure. Structural Architecture in the work of Mies van der Rohe

  • Santatecla Fayos, José
  • Lizondo Sevilla, Laura|||0000-0003-0376-0593
  • García Requejo, Zaida
[EN] Many critics and historians have spoken about structure in the work of Mies van der Rohe. However, few have studied the structure from a conceptual point of view, and in comparison with the different facets developed by Mies throughout his professional career. For this reason, this article does not seek to describe or classify the structural solutions used in his work, but instead to delve deeper into Mies' thoughts on the concept of structure and how this was adjusted to his architecture, both through his professional and teaching work. The text firstly analyses the evolution of Mies' concept of structure based on his writings and introduces the term "structural architecture", which summarises his last reflections and was considered by his students and collaborators as the fundamental principle of his architecture. Secondly, the article compares two projects tutored by Mies and developed by his students; both have the same typology, a single-family house, corresponding to each of Mies' teaching periods, at the Bauhaus and IIT. The research relates these academic projects with Mies' writings and completed projects, in order to verify whether there is any convergence between the thought of Mies van der Rohe and his work as an architect and as a teacher., [ES] Son muchos los críticos e historiadores que han hablado sobre la estructura en la obra de Mies van der Rohe, también los que han clasificado los diversos modos de sustentar sus edificios. Sin embargo, son pocos los que han estudiado la estructura desde un punto de vista conceptual y en comparativa con las diferentes facetas desarrolladas por Mies a lo largo de su carrera profesional. Por ello, lo que este artículo quiere exponer, no tiene que ver con describir o clasificar las soluciones estructurales de su obra, sino profundizar en el pensamiento de Mies en torno al concepto de estructura y cómo se iba ajustando en su arquitectura, tanto a través de la experiencia profesional como docente. En primer lugar, el texto analiza la evolución del concepto de estructura de Mies basándose en sus escritos e introduce el término de ¿arquitectura estructural¿, el cual sintetiza sus últimas reflexiones y es tomado por alumnos y colaboradores como principio fundamental de su arquitectura. En segundo lugar, el artículo compara dos proyectos tutorizados por Mies y desarrollados por sus alumnos; ambos de idéntica tipología, la vivienda unifamiliar, correspondientes a cada uno de los periodos docentes de Mies, Bauhaus y IIT. La investigación relaciona estos proyectos académicos con los escritos y la obra construida del maestro, a fin de comprobar si hay convergencia entre el pensamiento de Mies van der Rohe y su labor como arquitecto y como docente.

Estudio y mejora del proyecto de circunvalación de Albacete. Tramo Avenida de la Mancha, desde el camino de la Pulgosa hasta la Carretera de las Peñas CM-3203 (término municipal de Albacete)

  • González Rosa, María del Carmen
[EN] he present study aims to improve a bypass project carried out in the city of Albacete, analyzing the problems of road collapse in its infrastructures and the needs of road users. A description of the real executed project is made, including the location and related technical data. Next, the critical points are examined, such as, for example, the drainage system and the geometry of the track, adding complementary geological-geotechnical and environmental studies. Subsequently, different improvement solutions are proposed, among which are sustainable urban drainage systems and constructive alternatives. After a discussion based on socio-economic and environmental criteria, an optimal solution is obtained, which has been described in depth, economically valued and planned., [CAT] El present estudi té per objectiu la millora d'un projecte de circumval·lació realitzat a la ciutat d'Albacete, analitzant els problemes de col·lapse viari en les seues infraestructures i les necessitats dels usuaris d'aquestes. Es realitza una descripció del projecte real executat, incloent la localització i les dades tècniques relacionades. A continuació s'examinen els punts crítics, com per exemple, el sistema de drenatge i la geometria de la via, afegint per a això els estudis complementaris geològic-geotècnic i ambiental. Posteriorment es plantegen diferents solucions de millora, entre les quals es troben els sistemes de drenatge urbà sostenible i les alternatives constructives. Després d'una discussió sobre la base de criteris socioeconòmics i ambientals s'obté una solució òptima, la qual s'ha descrit en profunditat, valorat econòmicament i planificat., [ES] El presente estudio tiene por objetivo la mejora de un proyecto de circunvalación realizado en la ciudad de Albacete, analizando los problemas de colapso vial en sus infraestructuras y las necesidades de los usuarios de estas. Se realiza una descripción del proyecto real ejecutado, incluyendo la localización y los datos técnicos relacionados. A continuación se examinan los puntos críticos, como por ejemplo, el sistema de drenaje y la geometría de la vía, añadiendo para ello los estudios complementarios geológico-geotécnico y ambiental. Posteriormente se plantean diferentes soluciones de mejora, entre las que se encuentran los sistemas de drenaje urbano sostenible y las alternativas constructivas. Tras una discusión en base a criterios socio-económicos y ambientales se obtiene una solución óptima, la cual se ha descrito en profundidad, valorado económicamente y planificado.

Effects of salt and drought stress on seed germination and seedling growth in Portulaca

  • Borsai, Orsolya
  • Al Hassan, Mohamad
  • Boscaiu, Monica|||0000-0002-9691-4223
  • Sestras, Radu E.
  • Vicente, Oscar|||0000-0001-5076-3784
[EN] The effects of salt and water deficit on seed germination and early seedling growth were studied in six Portulaca accessions (P. oleracea L. ssp. oleracea, P. grandiflora Hook., P. grandiflora cvs. `Sundial Mango¿, `Double Pink¿ and `Double White¿, and P. halimoides L.). The aims of the study were to evaluate their responses to abiotic stress and to establish the relative degree of tolerance of the selected taxa. Seeds were germinated in the presence of increasing concentrations of NaCl or polyethylene glycol 6000 (to mimic drought conditions), generating the same osmotic potentials: 0, -0.25, -0.5 and -0.1 MPa. Germination percentage, mean germination time, seedling fresh weight and vigour index, and radicle, hypocotyl and cotyledon lengths were determined. Seed germination and seedling development decreased in all taxa in the presence of PEG and NaCl, in a concentration-dependent manner, although the effect of salt was stronger than that of PEG, at the same osmotic potentials. Germination and seedling parameters varied for the different accessions but, in practical terms, considering only the final germination percentages under stress, P. halimoides L. appears to be the taxon most tolerant to water deficit, whereas P. grandiflora Hook. would be the most tolerant to salt stress..

Effect of boosting system architecture and thermomechanical limits on diesel engine performance: Part I -Steady-state operation

  • Galindo, José|||0000-0001-6068-182X
  • Climent, H.|||0000-0002-2407-5651
  • Varnier, O.
  • Patil, Chaitanya Yashvant
[EN] Internal combustion engine developments are more focused on efficiency optimization and emission reduction for the upcoming future. To achieve these goals, technologies like downsizing and downspeeding are needed to be developed according to the requirement. These modifications on thermal engines are able to reduce fuel consumption and CO2 emission. However, implementation of these kind of technologies asks for right and efficient charging systems. This article consists of study of different boosting systems and architectures (single- and two-stage) with combination of different charging systems like superchargers and e-boosters. A parametric study is carried out with a zero-dimensional engine model to analyze and compare the effects of these different architectures on the same base engine. The impact of thermomechanical limits, turbo sizes and other engine development option characterizations are proposed to improve fuel consumption, maximum power and performance of the downsized/downspeeded diesel engines.

La disolución del aula: Finmere Primary School (1958-59), un aprendizaje integrador, específico y activo, The dissolution of the classroom: Finmere Primary School (1958-59), an integrative, specific and active learning

  • Lacomba-Montes, Paula|||0000-0002-1916-2689
  • Campos-Uribe, Alejandro|||0000-0002-9382-3481
[EN] The present article describes Finmere Primary School (1958-59), by the architects David and Mary Medd, which belongs to the Development Projects in Great Britain. The methodology of the article responds to Herbert Read¿s theses in his book Education through Art (1943) and influential professionals, Christian Schiller and Robin Tanner, who together with the Medds, supported his theories about the importance of the Arts in the personal development of the individual. The article focuses on describing how the spaces of the school, and the school as a whole, lend themselves to the development of the theories raised by these thinkers, to analyze the validity of their approaches in the present. The description of the project strategies helps to understand the architectural space in relation to some theoretical concepts that understand the human being as creative in a community environment. In the first place, the school will be explained as a single learning space without classrooms, promoting learning that integrates several disciplines. Next, as a place that absorbs the simultaneity of activities, a built-in variety school designed for specific activities. Finally, the school will be interpreted as a workshop that facilitates learning through experimentation and forces students to participate actively, building their own working corners. The article is limited to the study of a school in the British territory, as a particular case that allows us to see, through its evolution, how the educational and architectural discipline could jointly make a significant advance in the post-war schools. Finmere Primary School¿s project adapts to the pedagogical concepts still in force today, so we can learn from it fundamental strategies for the design of educational spaces., [ES] El artículo analiza la escuela de Finmere (1958-59) de los arquitectos David y Mary Medd, perteneciente a un grupo de proyectos conocidos como los Development Projects en el Reino Unido. La metodología del artículo atiende a las tesis de Herbert Read a través de su libro Educación por el arte (1943) y de profesionales influyentes como Christian Schiller y Robin Tanner que, junto con los Medd, apoyaban sus teorías acerca de la importancia del arte en el desarrollo personal del individuo. El artículo se centra en describir cómo los espacios de la escuela, y la escuela como conjunto, se prestan al desarrollo de las teorías planteadas por estos pensadores, para analizar la validez de sus planteamientos en la actualidad. La descripción de las estrategias proyectuales ayuda a comprender la forma del espacio arquitectónico basada en el ser humano como ser creativo en un ambiente comunitario. En primer lugar, se explica la escuela como un único espacio sin aulas, fomentando un aprendizaje que integra varias disciplinas. A continuación, como un lugar que absorbe la simultaneidad de actividades, una escuela hecha por partes (built-in variety), diseñada para actividades específicas. Por último, se interpreta la escuela como taller que facilita el aprendizaje a través de la experimentación y obliga a los alumnos a participar de forma activa, construyendo sus propios rincones de trabajo. El artículo se limita al estudio de una escuela en el territorio británico, como un caso particular que permite ver, a través de su evolución, cómo la disciplina educativa y la arquitectónica pudieron realizar conjuntamente un avance significativo en las escuelas de posguerra. El proyecto de Finmere se adapta a los conceptos pedagógicos vigentes aún, por lo que se puede aprender de ella estrategias fundamentales para el diseño de espacios educativos., Los autores agradecen el apoyo del Ministerio de Educación, Cultura y Deporte, del Gobierno de España

DNS of thermal channel flow up to Re-tau=2000 for medium to low Prandtl numbers

  • Alcántara-Ávila, Francisco
  • Hoyas, S.|||0000-0002-8458-7288
  • Pérez Quiles, María Jezabel
[EN] Direct Numerical Simulations of turbulent heat transfer in a channel flow are presented for three different Reynolds numbers, namely Re-tau = 500, 1000 and 2000. Medium and low values of the molecular Prandtl number are studied, ranging from 0.71 (air), down to 0.007 (molten metals), in order to study its effect on the thermal flow. Mixed boundary conditions at both walls are used for the thermal flow. Mean value and intensities of the thermal field were obtained. Two different behaviors were observed, depending on the Prandtl and Peclet numbers. The expected logarithmic behavior of the thermal flow completely disappears for Prandtl below 0.3. This is a direct effect of the thicker viscous thermal layer generated as the Prandtl number is reduced. Von Karman constant was computed for cases above this Prandtl, and turbulent Prandtl and Nusselt numbers were obtained for all the cases. Finally, the turbulent budgets for heat fluxes, temperature variance and its dissipation rate are presented. As a general result, there is a scaling failure near the wall in very cases studied, which is accentuated for lower Prandtl numbers. The statistics of all simulations can be downloaded from the web page of our group. (C) 2018 Elsevier Ltd. All rights reserved., This work was supported by MINECO/FEDER, under project ENE2015-71333-R. The computations of the new simulations were made possible by a generous grant of computing time from the Barcelona Supercomputing Centre, reference FI-2018-1-0037. We are grateful to Messiers Kawamura, Pirozzoli, Bernardini and Orlandi for providing us with copies of their original data.

Sistema LTI analógicos: Respuesta al impulso h(t)

  • Bernabeu Soler, Pablo Andrés|||0000-0002-6737-0212
Aquest objecte, permet al alumne entendre el per què de l'operació convolució en sistmes LTI. Es pretend que l'alumne entenga el posicionament fisic del integrant de l'operació convolució, així com la relació entre els instants finals e inicials del senyal de sortida d'un sistema LTI amb el senyal d'entrada i la resposta al impuls., S'ha d'usar per a entendre el comportament físisc de l''operació convolució .

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