Del monumento al paisaje urbano

Las intervenciones del Palacio Municipal, la Iglesia La Merced y la Estación Ferroviaria significan hechos importantes en el contexto histórico de la Ensenada y quizá el inicio de un programa de recuperación del rico patrimonio local marcado por acontecimientos de indudable valor para la memoria de los argentinos. El histórico edificio Municipal frente a la plaza principal de la localidad, calles La Merced esquina Don Bosco, significó el eslabón inicial del “Programa Preservación de Obras Públicas de Valor Histórico”. La Iglesia sobre la misma plaza Belgrano el siguiente eslabón. El crecimiento de Ensenada se apoyó en la llegada del ferrocarril. La Antigua Estación de trenes, que había alcanzado tal nivel de deterioro y abandono; es hoy también recuperada por la Municipalidad de Ensenada. Los tres edificios son parte de un proceso de renovación urbana, destinado a recuperar monumentos para disfrute y uso de la ciudadanía

Intervenciones contemporáneas en bienes de la tradición funcional

El reconocimiento del patrimonio edificado como signo de identidad y soporte de la memoria histórica comienza a dar lugar en su repertorio a nuevas categorías y las plantas industriales y los componentes ferro-portuarios se transforman en nuevos elementos que se han incorporado al campo del patrimonio arquitectónico en las últimas décadas. Coincidiendo con el movimiento moderno durante el siglo XX diversos factores vinculados a modelo de país y formatos de la producción fueron transformando la imagen de los componentes industriales y ferroviarios desdibujando su austera expresión original Las intervenciones del Museo del Ladrillo en la antigua administración de la fabrica Ctibor y la Estación Ferroviaria de Ensenada devenida en Centro Cívico Cultural presentan acciones de rehabilitación en el contexto histórico de nuestra región y jalonan la recuperación del rico patrimonio de la tradición funcional local, marcado por acontecimientos de indudable valor para la memoria de los argentinos

Relative Asymptotic of Multiple Orthogonal Polynomials for Nikishin Systems

We prove relative asymptotic for the ratio of two sequences of multiple orthogonal polynomials with respect to Nikishin system of measures. The first Nikishin system ${\mathcal{N}}(\sigma_1,...,\sigma_m)$ is such that for each $k$, $\sigma_k$ has constant sign on its compact support \supp {\sigma_k} \subset \mathbb{R} consisting of an interval $\widetilde{\Delta}_k$, on which $|\sigma_k^{\prime}| > 0$ almost everywhere, and a discrete set without accumulation points in $\mathbb{R} \setminus \widetilde{\Delta}_k$. If {Co}(\supp {\sigma_k}) = \Delta_k denotes the smallest interval containing \supp {\sigma_k}, we assume that $\Delta_k \cap \Delta_{k+1} = \emptyset$, $k=1,...,m-1$. The second Nikishin system ${\mathcal{N}}(r_1\sigma_1,...,r_m\sigma_m)$ is a perturbation of the first by means of rational functions $r_k$, $k=1,...,m,$ whose zeros and poles lie in $\mathbb{C} \setminus \cup_{k=1}^m \Delta_k$.Comment: 30 page

Environmental and economic assessment of biodegradable and compostable alternatives for plastic materials in greenhouses

Data for this article was collected in the projects “REmanufacture the food supply chain by testing INNovative solutions for zero inorganic WASTE (REINWASTE)”, integrated in the Interreg Med programme and co-financed by the European Regional Development Fund under grant agreement 3300, and “Actividades de demostración e información para la gestión de residuos sólidos derivados de la horticultura protegida (RECICLAND - PP.RSRR.RSRR1900.001)”, co-financed by the European Regional Development Fund, in the Rural Development Program of Andalusia 2014-2020, Operation PDR C15C0122U1. Guillermo Garcia-Garcia acknowledges the Grant ‘Juan de la Cierva Incorporación’ funded by MCIN/AEI/ 10.13039/501100011033 and “ESF Investing in your future”, and the Grant ‘Marie Skłodowska-Curie Actions (MSCA) Postdoctoral Fellowship’ with Grant agreement ID: 101052284. We acknowledge funding for open access provided by Universidad de Granada/CBUA.Plastics and other materials commonly used in horticulture for plant support (e.g. raffia) and soil protection (e.g. mulching film) pose a challenge to achieving a circular economy. These materials contaminate plant residues, hampering their direct reuse due to the need for separation and cleaning. As a result, contaminated plant residues is often landfilled or incinerated. This study investigates the replacement of conventional plastic raffia and mulching film with biodegradable and compostable alternatives. Polypropylene raffia is compared with a biodegradable viscose polymer and compostable jute fibre, while polyethylene mulching film is compared with a biodegradable polylactic acid film. Conventional and novel alternatives are compared economically using Life-Cycle Costing and environmentally using Life-Cycle Assessment. The economic assessment is based on case studies with two horticultural companies in Almeria (south-eastern Spain), while the environmental analysis uses data from the Ecoinvent database. The use of biodegradable and compostable alternatives for raffia and mulching film proved to be 49% more expensive than conventional options. However, when conventional plastic waste is incinerated rather than landfilled, biodegradable and compostable alternatives have a lower carbon footprint. Although biodegradable and compostable options can be more expensive and have higher impacts in certain situations, proper waste management can lead to environmental benefits. With optimisation and incentives, these alternative options support the transition of horticulture to a sustainable circular economy.European Regional Development Fund 3300Rural Development Program of Andalusia 2014-2020, Operation PDR C15C0122U1MCIN/AEI/ 10.13039/501100011033 “ESF Investing in your future”‘Marie Skłodowska-Curie Actions (MSCA) ID: 101052284Universidad de Granada/CBU

Rotating and counterrotating relativistic thin disks as sources of stationary electrovacuum spacetimes

A detailed study is presented of the counterrotating model (CRM) for electrovacuum stationary axially symmetric relativistic thin disks of infinite extension without radial stress, in the case when the eigenvalues of the energy-momentum tensor of the disk are real quantities, so that there is not heat flow. We find a general constraint over the counterrotating tangential velocities needed to cast the surface energy-momentum tensor of the disk as the superposition of two counterrotating charged dust fluids. We then show that, in some cases, this constraint can be satisfied if we take the two counterrotating tangential velocities as equal and opposite or by taking the two counterrotating streams as circulating along electro-geodesics. However, we show that, in general, it is not possible to take the two counterrotating fluids as circulating along electro-geodesics nor take the two counterrotating tangential velocities as equal and opposite. A simple family of models of counterrotating charged disks based on the Kerr-Newman solution are considered where we obtain some disks with a CRM well behaved. We also show that the disks constructed from the Kerr-Newman solution can be interpreted, for all the values of parameters, as a matter distribution with currents and purely azimuthal pressure without heat flow. The models are constructed using the well-known "displace, cut and reflect" method extended to solutions of vacuum Einstein-Maxwell equations. We obtain, in all the cases, counterrotating Kerr-Newman disks that are in agreement with all the energy conditions.Comment: 22 pages, 7 figures, Late

Arcillas cerámicas de Andalucía IV. Yacimientos terciarios de La Campiña, en la provincia de Córdoba

Sixteen samples of clays, interesting from the ceramic viewpoint, from several beds located on the southwest of Cordoba, in the country named Campiña, within an extension of 400 sq. Km. of area, including soils of Puente Genil, Lucena, Aguilar de la Frontera and La Rambla, have been studied. The materials belonging to Tertiary's sediments (Eocene and Miocene) made up of enough argillous chalk, sometimes are very sandy and are used to make bricks. The following techniques have been used: chemical, mechanical and ponderal thermal analysis, D. T. A., base exchange capacity, X-ray diffraction analysis, plasticity, drying shrinkage at 25º C. (Bourry's diagrams), drying shrinkage and crushing strength in fired bodies. It is concluded that the main component of these clays is mont-morillonite followed by kaollinite and illite in several stages of transformation. In some samples the illite content is higher than that of kallinite. Muscovite, oxides of iron and aluminium in several stages of hydration or in gels form, chlorites, feldspars and some free silica follow the above mentioned minerals in importance. The raw materials contain important amounts of calcite of very fine grain; about 30-40 %. The technological tests suggest that these raw materials have good ceramic properties for pottery's products and building materials. Location of these beds and their subsequent ceramic industries on the center of the triangle Seville-Malaga-Cordoba, increase their economic considerations.Se han estudiado dieciséis muestras de arcilla de interés cerámico procedentes de varios yacimientos situados en la región SW. de la provincia de Córdoba, en la comarca denominada Campiña, dentro de un área de 400 Km, comprendiendo terrenos de Puente Genil, Lucena, Aguilar de la Frontera y La Rambla. Los materiales proceden de sedimentos terciarios (Eoceno y Mioceno) formadas por margas bastante arcillosas, que a veces son más arenosas y se explotan para la fabricación de ladrillos. Las técnicas empleadas han sido las siguientes: Análisis químico, capacidad de cambio, análisis térmico diferencial y ponderal, diagramas de difracción de rayos X, análisis mecánico, agua de moldeo, plasticidad (Riecke), secado a 25ºC (diagramas de Bourry), contracción por calcinación y resistencia a la compresión. Se deduce que el componente principal de estas arcillas es la mont-morillonita, seguida de caolinita e illita en diversos estados de alteración. En alguna muestra el porcentaje de illita supera al de caolinita. A los minerales citados siguen en interés micas potásicas, óxidos de hierro y de aluminio en diversos grados de hidratación o en forma de geles, cloritas, feldespatos y un cierto porcentaje de cuarzo libre. Las muestras naturales contienen cantidades importantes de carbonato cálcico, del 30 al 40 %, en grano muy fino. Las pruebas tecnológicas coinciden en que se trata de materiales naturales de buenas condiciones tecnológicas y económicas para fabricar productos de alfarería y materiales de construcción. El interés económico de estos yacimientos y el de las industrias cerámicas respectivas se ve favorecido por su situación geográfica en el centro del triángulo Sevilla-Málaga-Córdoba

The Martin-Benito-Mena Marugan-Olmedo prescription for the Dapor-Liegener model of Loop Quantum Cosmology

Recently, an alternative Hamiltonian constraint for Loop Quantum Cosmology has been put forward by Dapor and Liegener, inspired by previous work on regularization due to Thiemann. Here, we quantize this Hamiltonian following a prescription for cosmology proposed by Mart\'{\i}n-Benito, Mena Marug\'an, and Olmedo. To this effect, we first regularize the Euclidean and Lorentzian parts of the Hamiltonian constraint separately in the case of a Bianchi I cosmology. This allows us to identify a natural symmetrization of the Hamiltonian which is apparent in anisotropic scenarios. Preserving this symmetrization in isotropic regimes, we then determine the Hamiltonian constraint corresponding to a Friedmann-Lema\^itre-Robertson-Walker cosmology, which we proceed to quantize. We compute the action of this Hamiltonian operator in the volume eigenbasis and show that it takes the form of a fourth-order difference equation, unlike in standard Loop Quantum Cosmology, where it is known to be of second order. We investigate the superselection sectors of our constraint operator, proving that they are semilattices supported only on either the positive or the negative semiaxis, depending on the triad orientation. Remarkably, the decoupling between semiaxes allows us to write a closed expression for the generalized eigenfunctions of the geometric part of the constraint. This expression is totally determined by the values at the two points of the semilattice that are closest to the origin, namely the two contributions with smallest eigenvolume. This is in clear contrast with the situation found for the standard Hamiltonian of Loop Quantum Cosmology, where only the smallest value is free. This result indicates that the degeneracy of the new geometric Hamiltonian operator is equal to two, doubling the possible number of solutions with respect to the conventional quantization considered until now.Comment: 15 pages, published in Physical Review

Los medios españoles en la campaña de 2008

En este capítulo se busca contextualizar el comportamiento de los medios de comunicación españoles, su connivencia o complacencia con el poder (con determinadas manifestaciones del poder), en relación con su distribución en torno de un reducido número de grandes grupos mediáticos. Ello nos permitirá enlazar a continuación con el análisis específico de su papel en la campaña de 2008, así como del potencial, desde el punto de vista del fomento del pluralismo, atesorado por los nuevos medios de comunicación desarrollados recientemente en la red Internet, fundamentalmente los agrupados en la denominada “blogosfera”

Toponimia del tejo

El río Tajo parece deber su nombre a un tejo. Teja y taja, formas femeninas de tejo, son más frecuentes en la toponimia de lo que suele suponerse. Tejera Negra remite sin duda a tejos. Mosquito aparece varias veces relacionado con el tejo. Es probable que Texas (EE.UU.) deba su nombre a la abundancia de lexos