Fabricación histórica de ladrillos refractarios en Valdemorillo, Madrid: Minas y fábricas de D. Ángel González

Desde el catastro del Marqués de la Ensenada (1752-1753) hasta nuestros días hay datos sobre la existencia de tejares y alfares en Valdemorillo. La existencia al SE del municipio de un alargado afloramiento del Utrillas, rico en caolines, hizo que se instalaran en su término, a partir de 1845, fábricas de loza y de ladrillo refractario. Nosotros hemos estudiado una de estas instalaciones, se trata de las minas subterráneas y hornos de D. ÁNGEL GONZÁLEZ, que aún se conservan en relativo buen estado, constituyendo un Patrimonio Arqueológico Industrial de interés. Los estudios se han realizado en el marco de un proyecto de investigación de la Consejería de Educación de la Comunidad de Madrid, titulado: "Arqueología Industrial: Conservación del patrimonio minero-metalúrgico madrileño (II)"

Base de datos informatizada en Proyectos de Patrimonio Minero-Metalúrgico. Aplicaciones al caso de Madrid

El proyecto "CONSERVACiÓN DEL PATRIMONIO MINERO Y METALÚRGICO MADRILEÑO-U", segunda fase del iniciado bajo el título "ARQUEOLOGíA INDUSTRIAL: CONSERVACIÓN DEL PATROMINIO MINEROMETALÚRGICO MADRILEÑO", forma parte de la Convocatoria de Proyectos de Investigación en Humanidades y Ciencias Sociales de la Comunidad Autónoma de Madrid. En el primer estudio se pretendía abordar la evaluación, clasificación y catalogación de aquellos elementos, relacionados con el ámbito minero y metalúrgico, que estuvieran vinculados a la Comunidad Autónoma de Madrid

Hornos cerámicos para tejas y ladrillos de la Presa del Rey, San Martín de la Vega, Madrid

Si abandonamos la carretera comarcal de Madrid a San Martín de la Vega, rumbo Górquez de Abajo y a la Boyeriza, unos 500 m antes de llegar a la Presa o Embalse del Rey, sobre el río Jarama, podemos observar, al pie de los escarpes yesíferos miocenos, un horno cerámico, relativamente bien conservado. El horno, excavado en tierra para aprovechar la mala conductividad de esta, se disimula entre el paisaje por causa de su construcción externa en adobe, los cuales están conformados con los mismos materiales que constituyen allí el suelo (Fotos.-1 y 2). El adobe se haría con materiales procedentes de niveles, poco potentes, de limos arenosos ubicados en la parte superior de las terrazas fluviales, que sirvieron también para fabricar los ladrillos y tejas, que encontramos diseminados en el entorno. El estudio del punto considerado se ha realizado en el marco de un proyecto de la Consejería de Educación de la Comunidad de Madrid, titulado Arqueología Industrial: Conservación del Patrimonio Minero Metalúrgico Madrileño de la Comunidad de Madrid (II)

Hornos cerámicos antiguos de la Comunidad de Madrid: Campo Real

Hemos reconocido los hornos cerámicos antiguos existentes en el término municipal de Campo Real, dialogando cuando ha sido posible con sus artesanos. Se pretende el inventario y la conservación de los elementos arqueológicos industriales, de índole minero-metalúrgica, pero a la vez estamos interesados en las técnicas productivas abandonadas y en la historia de las instalaciones. Estos estudios los realizamos en el marco de un Proyecto de Investigación, financiado por la Consejería de Educación de la Comunidad de Madrid, titulado: "Arqueología Industrial Conservación del Patrimonio Minero-Metalúrgico madrileño"

Liquid crystal behavior of the Kihara fluid

The liquid crystal phases of the Kihara fluid have been studied in computer simulations. The work focuses on the isotropic–nematic–smectic-A triple point region, especially relevant for the understanding of the properties and the design of real mesogens with specific phase diagrams. The Kihara interaction resembles more appropriately than other related models, the shape of elongated polymers and biomolecules, and a closer assertion is provided for the role of the configurational entropy and the dispersive interactions in the behavior of such molecules in dense phases or under macromolecular crowding conditions.Dirección Genaral de Investigación Científico y Técnica BQU2001-3615-C02Instituto de Salud Carlos III 01/1664Plan Andaluz de Investigación FQM-205, FQM-31

Use of Parsons-Lee and Onsager theories to predict nematic and demixing behavior in binary mixtures of hard rods and hard spheres

Parsons-Lee and Onsager theories are formulated for the isotropic-nematic transition in a binary mixture of hard rods and hard spheres. Results for the phase coexistence and for the equation of state in both phases for mixtures with different relative sizes and composition are presented. The two theories explain correctly the general behavior observed in experiments and computer simulations for these fluids. In particular, the theory accounts for the destabilization of the nematic phase when spherical or globular macromolecules are added to a system of rodlike colloids, and the entrance of the system into a demixed regime at high volume fractions of the spherical particles. Upon demixing a nematic state rich in rods coexists in equilibrium with an isotropic state much more diluted in the rodlike component. Onsager theory fails on quantitative grounds for aspect ratios of the rodlike molecules smaller than 100, and in the cases where the molar fractions of spheres becomes close to unity. On the contrary, the Parsons-Lee approximation remains accurate down to aspect ratios as small as 5. The spinodal analysis indicates that the isotropic-isotropic and nematic-nematic coexistences become feasible for sufficiently large spheres and long rods, respectively. The latter type of coexistence interferes partially with the isotropic-nematic coexistence regime of interest to the present work. Overall, the study serves to rationalize and control key aspects of the behavior of these binary nematogenic colloidal systems, which can be tuned with an appropriate choice of the relative size and molar fractions of the particles.Ministerio de Educación y Ciencia CTQ2004- 07730-C02 VEM2003-20574-C03Junta de Andalucía PAI FQM-205 FQM-31

A novel orientation-dependent potential model for prolate mesogens

An intermolecular potential is introduced for the study of molecular mesogenic fluids. The model combines distinct features of the well-known Gay-Berne and Kihara potentials by incorporating dispersive interactions dependent on the relative pair orientation to a spherocylinder molecular core. Results of a Monte Carlo simulation study focused on the liquid crystal phases exhibited by the model fluid are presented. For the chosen potential parameters, molecular aspect ratio L*55 and temperatures T*52, 3, and 5, isotropic, nematic, smectic-A, and hexatic phases are found. The location of the phase boundaries as well as the equation of state of the fluid and further thermodynamical and structural parameters are discussed and contrasted to the Kihara fluid. In comparison to this latter fluid, the model induces the formation of ordered liquid crystalline phases at lower packing fractions and it favors, in particular, the appearance of layered hexatic ordering as a consequence of the greater attractive interaction assigned to the parallel side-to-side molecular pair configurations. The results contribute to the evaluation of the role of specific interaction energies in the mesogenic behavior of prolate molecular liquids in dense environments

Monte Carlo study of liquid crystal phases of hard and soft spherocylinders

We report on a Monte Carlo study of the liquid crystal phases of two model fluids of linear elongated molecules: ~a! hard spherocylinders with an attractive square-well ~SWSC! and ~b! purely repulsive soft spherocylinders ~SRS!, in both cases for a length-to-breadth ratio L*55. Monte Carlo simulations in the isothermal–isobaric ensemble have been performed at a reduced temperature T*55 probing thermodynamic states within the isotropic ~I!, nematic ~N!, and smectic A ~Sm A! regions exhibited by each of the models. In addition, the performance of an entropy criterion to allocate liquid crystalline phase boundaries, recently proposed for the isotropic–nematic transition of the hard spherocylinder ~HSC! fluid, is successfully tested for the SWSC and the SRS fluids and furthermore extended to the study of the nematic–smectic transition. With respect to the more extensively studied HSC fluid, the introduction of the attractive square well in the SWSC model brings the I–N and N–Sm A transitions to higher pressures and densities. Moreover, the soft repulsive core of the SRS fluid induces a similar but quite more significant shift of both of these phase boundaries toward higher densities. This latter effect is apparently in contrast with very recent studies of the SRS fluid at lower temperatures, but this discrepancy can be traced back to the different effective size of the molecular repulsive core at different temperatures