Understanding subterranean grain storage heritage in the Mediterranean region: The Valencian silos (Spain)

Underground space has widely been used through history, provided either by natural or by dug cavities that were used as storage for farming production. In particular, cereals has constantly been present in the Mediterranean cultures. Their preservation was crucial in the Mediterranean grain trade for local and urban growth. The main goal of this multidisciplinary study is to analyse the typological and architectural characteristics of underground Mediterranean granary structures. It also discusses the excavation process for building a silo, focusing in a study of the Valencian silos at the Spanish Mediterraean shore. The Valencian silo-yard was essential for the socio-economic city development in the 16th century. this is the first research performed on this subterranean ensemble, by searching through historical documents and using a non-destructive technique (NDT) as Ground Penetrating Radar (SIR-3000, GSI) with 100 MHZ and 400 MHZ antennae. The composition soil was obtained for hydrogeological characteristics by goetechnical tests. Besides, laser scanner and GPS surveys were carried out for mapping the silo-yard in detail. Since the Valencian silos are a relevant example of subterranean engineering storage, we were able to carry out a comparative study of significant Mediterranean silos (from Algeria, Italy, Jordan, Malta and Turkey) by reviewing documentation. As a result, these underground spaces share numerous features, as type of terrain, excavation process, geographic location, morphology, dimensions, sealing system, usage, etc. These similar features illustrate that a subterranean grain storage stereotype is present in the Mediterranean región heritage.The authors would like to thank Valencia and Burjassot city councils for letting us carry out this research of the Valencian silos, as well as to the Historical Archive of Valencia for the attention and helpful suggestions. We would like to show our gratitude to the people who have collaborated with diverse information, as the author Mr. Miret and the manager of Events & Customer Care in Malta Tourism Authority, Mr. Morana. Also we would like to express our appreciation to the Valencian Government, which through a pre-doctoral grant has funded this research (ACIF/2011/032).Valls Ayuso, A.; García García, F.; Ramírez Blanco, MJ.; Benlloch Marco, J. (2015). Understanding subterranean grain storage heritage in the Mediterranean region: The Valencian silos (Spain). Tunnelling and Underground Space Technology. 50:178-188. https://doi.org/10.1016/j.tust.2015.07.003S1781885

A Combined Use of GPR Data With Historical Archives for Identifying Pavement Construction Periods of Valencian Silos (16th Century, Spain)

© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper describes the combined use of ground penetrating radar (GPR) data with historical archives performed in the silo-yard of Valencia (Spain) to identify and map various pavement construction periods. The Valencian silos were constructed to house the underground grain storage of Valencia City. This architectural complex is composed of three buildings and a big square (silo-yard), under which 41 silos are placed. The construction of the silo-yard pavement extended for two centuries (16 18th century) following different construction systems. Historical archives confirmed seven pavement construction periods. However, archive data provided scant information on pavement layers and the construction periods. A GPR survey was carried out for pinpointing the seven pavement construction periods. A GSSI SIR-3000 equipment with a 400-MHz frequency antenna was used for collecting 1 × 1 m grid −141 profiles across the square (5110 m2), reaching 1.5-m depth. In addition, a GPS survey was performed specifically for surface mapping the silo-yard in detail. The combined use of the GPR data (2-D reflection profiles, spectra, and amplitude slice maps) with the historical archives allowed identifying and delineating the different pavement construction periods on the silo-yard map in terms of materials and thicknesses. These results demonstrate GPR is a noninvasive and nondestructive technique for mapping soils and near surface horizons. Additionally, the combined use of the GPR data with the historical documentation makes this technique even more efficient for the comprehension of shallow ground layers, especially in cultural heritage studies.This work was supported by the Valencian Government under Grant ACIF/2011/032. This paper was presented in part at the 15th Annual International Conference on Ground Penetration Radar GPR 2014, Square Brussels Meeting Centre, Brussels, Belgium, June 30-July 4, 2014.Valls Ayuso, A.; García García, F.; Ramírez Blanco, MJ.; Benlloch Marco, J. (2015). A Combined Use of GPR Data With Historical Archives for Identifying Pavement Construction Periods of Valencian Silos (16th Century, Spain). IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. 9:1-10. https://doi.org/10.1109/JSTARS.2015.2466192S110

Accurate computation of the Moore-Penrose inverse of strictly totally positive matrices

The computation of the Moore-Penrose inverse of structured strictly totally positive matrices is addressed. Since these matrices are usually very ill-conditioned, standard algorithms fail to provide accurate results. An algorithm based on the factorization and which takes advantage of the special structure and the totally positive character of these matrices is presented. The first stage of the algorithm consists of the accurate computation of the bidiagonal decomposition of the matrix. Numerical experiments illustrating the good behavior of our approach are included.Numerical experiments illustrating the good behavior of our approach are included

Morphological and structural behavior of TiO2 nanoparticles in the presence of WO3: crystallization of the oxide composite system

Composite TiO2–WO3 oxide materials were prepared by a single pot microemulsion method and studied during calcination treatments under dry air in order to analyze the influence of tungsten on the behavior of the dominant titania component. To this end, the surface and bulk morphological and structural evolution of the solid precursors was studied using X-ray diffraction and infrared spectroscopy. In the calcination process, differences in the dominant titania component behavior appeared as a function of the W/Ti atomic ratio of the precursor. First, the crystallization of the anatase phase is affected by tungsten through an effect on the primary particle size growth. Furthermore, such an effect also influences the anatase to rutile phase transformation. The study provides evidence that the W–Ti interaction develops differently for a low/high W/Ti atomic ratio below/above 0.25 affecting fundamentally the above-mentioned anatase primary particle size growth process and the subsequent formation of the rutile phase and showing that addition of tungsten provides a way to control morphology and phase behavior in anatase-based oxide complex materialsComisión Interminsterial de Ciencia y Tecnología CT2010- 14872/BQUJunta de Andalucía FQM6090Consejo Superior de Investigaciones Científicas 201460E00

Aparición y crecimiento de los ETF en españa: una interesante inversión alternativa poco conocida en tiempos de crisis

A pesar de la reciente aparición de los fondos cotizados (Exchange Traded Funds, ETF) en España, estos han alcanzado una importancia considerable, con una inversión superior a los 44.560 millones de euros en junio de 2015. Los ETF son productos híbridos entre los fondos de inversión y los títulos de renta variable, que replican un índice y cotizan en mercados regulados. Se han convertido en una inversión estratégica en periodos de crisis dada su gran accesibilidad, por lo que analizamos sus características, principales magnitudes y evolución, así como las ventajas respecto a los fondos tradicionales de este prometedor producto de inversión

Accurate computations with collocation matrices of the Lupaş-type (p,q)-analogue of the Bernstein basis

A fast and accurate algorithm to compute the bidiagonal decomposition of collocation matrices of the Lupaş-type (p,q)-analogue of the Bernstein basis is presented. The error analysis of the algorithm and the perturbation theory for the bidiagonal decomposition are also included. Starting from this bidiagonal decomposition, the accurate and efficient solution of several linear algebra problems involving these matrices is addressed: linear system solving, eigenvalue and singular value computation, and computation of the inverse and the Moore-Penrose inverse. The numerical experiments carried out show the good behaviour of the algorithm.Agencia Estatal de Investigació

Error analysis, perturbation theory and applications of the bidiagonal decomposition of rectangular totally-positive h-Bernstein-Vandermonde matrices

A fast and accurate algorithm to compute the bidiagonal decomposition of rectangular totally positive h-Bernstein-Vandermonde matrices is presented. The error analysis of the algorithm and the perturbation theory for the bidiagonal decomposition of totally positive h-Bernstein-Vandermonde matrices are addressed. The computation of this bidiagonal decomposition is used as the first step for the accurate and efficient computation of the singular values of rectangular totally positive h-Bernstein-Vandermonde matrices and for solving least squares problems whose coefficient matrices are such matrices.Agencia Estatal de Investigació

Soil pH effects on the Toxicity of zinc oxide nanoparticles to soil bacterial communities.

The environmental levels of ZnO nanoparticles (nZnO) are increasing continually given the widespread and expanding applications of this material. Soil pH appears to be one of the key factors affecting the behavior and toxicity of metal nanoparticles in soi

Least squares problems involving generalized Kronecker products and application to bivariate polynomial regression

A method for solving least squares problems (A ⊗ Bi)x = b whose coefficient matrices have generalized Kronecker product structure is presented. It is based on the exploitation of the block structure of the Moore-Penrose inverse and the reflexive minimum norm g-inverse of the coefficient matrix, and on the QR method for solving least squares problems. Firstly, the general case where A is a rectangular matrix is considered, and then the special case where A is square is analyzed. This special case is applied to the problem of bivariate polynomial regression, in which the involved matrices are structured matrices (Vandermonde or Bernstein-Vandermonde matrices). In this context, the advantage of using the Bernstein basis instead of the monomial basis is shown. Numerical experiments illustrating the good behavior of the proposed algorithm are included.Ministerio de Economía y Competitivida

Nuberu : Reliable RAN Virtualization in Shared Platforms

RAN virtualization will become a key technology for the last mile of next-generation mobile networks driven by initiatives such as the O-RAN alliance. However, due to the computing fluctuations inherent to wireless dynamics and resource contention in shared computing infrastructure, the price to migrate from dedicated to shared platforms may be too high. Indeed, we show in this paper that the baseline architecture of a base station¿s distributed unit (DU) collapses upon moments of deficit in computing capacity. Recent solutions to accelerate some signal processing tasks certainly help but do not tackle the core problem: a DU pipeline that requires predictable computing to provide carrier-grade reliability. We present Nuberu, a novel pipeline architecture for 4G/5G DUs specifically engineered for non-deterministic computing platforms. Our design has one key objective to attain reliability: to guarantee a minimum set of signals that preserve synchronization between the DU and its users during computing capacity shortages and, provided this, maximize network throughput. To this end, we use techniques such as tight deadline control, jitter-absorbing buffers, predictive HARQ, and congestion control. Using an experimental prototype, we show that Nuberu attains 95% of the theoretical spectrum efficiency in hostile environments, where state-of-art approaches lose connectivity, and at least 80% resource savingsWe would like to thank our shepherd and reviewers for their valuable comments and feedback. This work has been supported by the European Commission through Grant No. 101017109 (DAEMON project) and Grant No. 101015956 (Hexa-X project), and the CERCA Programme/Generalitat de Catalunya