Geoenvironmental Characterization of Sulfide Mine Tailings

Spain has a long mining tradition dating from pre-historic times up to the present day. The cessation of mining activity has generated a large amount of mine wastes, most of which represent geochemical hazards. Mine tailings are watery sludge composed of medium-to-fine-grained material, resulting from grinding and mineral processing (e.g., galena, pyrite, sphalerite, and arsenopyrite). They entail both an accumulation and a potential subsequent emission source of trace elements (i.e. As, Cu, Fe, Pb, and Zn) with formation of acid mine drainage (AMD). Mineralogical and geochemical techniques (in combination with geophysical surveys and aerial photographs studies) have been jointly applied to selected mine areas. Seven mine deposits from the most important mine districts in Spain have been selected: Iberian Pyrite Belt, Cartagena-La Unión, Alcudia Valley, and Mazarrón. The main goal is focused on getting a geoenvironmental characterization as complete as possible by determining the geometry, evolution in time and composition of mine ponds, and the possible occurrence of AMD, for identifying related environmental hazards

Modelling decision making in the management of national parks

Trabajo presentado al 14th International Symposium on the Analytic Hierarchy Process celebrado en Washington (US) del 29 de junio al 2 de julio de 2014.A procedure for determining the influential factors in NP management and supporting participatory decision making is proposed. The procedure was applied to the Waraira Repano national park (WRNP) in Venezuela. Key aspects found for the effective management of WRNP showed to be Driving forces like "Human population growth" or "Patterns of use of natural resources"; Pressures like "Forest fires" and "Illegal human settlements"; States like "Biodiversity composition and abundance" and "Ecosystem and landscape integrity"; Impacts like "Natural resources depletion" or "Altered connectivity"; and Responses like "Stakeholders" participation" or "Environmental surveillance". Finally, key indicators have been proposed to monitor the evolution of these influential factors. Also, the findings confirm that stakeholders hold different interests, approaches to sustainability and sensitivities. After ANP all stakeholders understand better their interests and the others". Thus, an improved participation is obtained and a consensus, or at least general agreements, is more likely. Also a better commitment to the overall objective is achieved as the decision model facilitates improving the alternatives design in order to lessen the possible burdens for specific stakeholders or the environment.The research presented in this paper has been co-funded by the the Universitat Politècnica de València and the Decanato de Investigación y Desarrollo Académico of Universidad Metropolitana in Venezuela.Peer Reviewe

Auditoría energética en edificios residenciales. Estudio para la mejora de la eficiencia energética en rehabilitación

Este proyecto nace como resultado de un proyecto real, consistente en la certificación energética de un bloque de viviendas que lleva construido 30 años. Pretende llevarse a cabo una rehabilitación que no sólo mejore el aspecto del mismo, sino que también mejore su eficiencia energética. Los resultados de estas mejoras han sido plasmados mediante la certificación energética realizada con el programa normativo CALENER VyP. El objetivo principal del proyecto es visualizar de forma clara y objetiva, mediante un programa informático normativo, que la rehabilitación sugerida consigue mejorar la eficiencia energética del edificio, así como generar ahorros en el consumo de combustible de la comunidad. Para la consecución de este objetivo principal, se desarrollan diferentes estudios de mejora en la rehabilitación energética del edificio. Así pues, en este proyecto se analizan varios puntos: •Cerramientos de edificio: Se estudia cómo pueden mejorarse mediante los cálculos de transmitancia según el Código Técnico de la Edificación. Se realiza también una comparativa con los costes de llevar a cabo estas mejoras para ver qué resultado es el más adecuado. •Puentes térmicos: Se visualiza y analiza el estado actual de los mismos mediante termografías y se realiza el estudio de las mejoras que supone la rehabilitación propuesta en cerramientos. •Integración de energía solar térmica: Se calcula el porcentaje de cobertura solar para conseguir reducir consumos en agua caliente sanitaria. Como implementación a este apartado se realiza el proyecto de la instalación, así como el estudio económico del mismo. •Cálculo de la eficiencia energética del edificio y reducción de consumos: Con las mejoras propuestas se realiza el cálculo final, en el que se compara el estado inicial y el final del edificio y se concluye con datos fiables cual es el ahorro que supone la rehabilitación. •Estudio de viabilidad económica: Una vez calculados los ahorros se comparan con los costes, incluyendo el aporte de posibles subvenciones, para concluir un periodo de amortización de las propuestas. Todos estos estudios dan como resultado que, gracias a la rehabilitación propuesta, se reduce el consumo del edificio en un 60%, dando como resultado un periodo de amortización de 11 años

Graphic study and geovisualization of the old windmills of La Mancha (Spain)

In Spain, one can find geographical diversity and unique sites of great significance and cultural heritage. Many of the nation’s treasured places, however, have deteriorated or have even disappeared. What is left, then, should be studied and documented both graphically and infographically. It is important to preserve and document Spain’s unique locations, especially those related to vernacular heritage, to transhumance and visual impact assessment in many national infrastructures projects. Windmills are important examples of agro-industrial heritage and are sometimes found in the beds of streams and rivers but can also be found high in the hills. Their presence is constant throughout the Iberian Peninsula. These mills are no longer in use due to technological advances and the emergence of new grinding systems. The aim of this study was to present a specific methodology for the documentation of windmills, to create a graphical representation using computer graphics, as well as to disseminate knowledge of this agro-industrial heritage. This research has integrated graphic materials, including freehand sketches, photographs, digital orthophotos, computer graphics and multimedia in the creation of a specific methodology based on cutting-edge technology such as a digital photogrammetric workstation (DPW), global navigation satellite systems (GNSS), computer-aided design (CAD) and computer animation

Precisión en MDEs generados mediante correlación automática aplicados al estudio de espacios singulares

En este trabajo se muestra una experiencia en la generación de Modelos Digitales de Elevaciones (MDEs) a partir de algoritmos de correlación automática propios de una Estación de Fotogrametría Digital (EFD), así como una evaluación sobre la precisión obtenida en función de los datos disponibles y de la metodología empleada. Este estudio se aplica a un espacio singular denominado cerro “Calderico” en el que se ubican los famosos molinos de viento de Don Quijote en Consuegra (Toledo, España), donde se diferencian tres zonas, caracterizadas principalmente por su distinta pendiente. Una vez creados los diferentes MDEs para los ámbitos descritos se efectúa un análisis estadístico que nos servirá para hacer una valoración cualitativa tanto de los modelos como de las ortoimágenes que se obtengan. Los resultados que se aportan indican mayor disparidad en la precisión de los puntos homólogos identificados en cada MDE para las zonas de más desnivel y menor en las zonas con pendiente más suave. Es interesante observar la buena calidad de los puntos controlados mediante GPS diferencial

A Geochemical and Geophysical Characterization of Sulfide Mine Ponds at the Iberian Pyrite Belt (Spain)

This work presents the results of a geochemical and geophysical characterization of the Monte Romero and La Naya mine ponds, belonging to the Cueva de la Mora and Riotinto mine districts, respectively, based on mineralogical, geochemical and geophysical techniques. In order to obtain a representative environmental characterization, two deposits showing different mineralogies, physico-chemical parameters, chemical compositions of tailings and pond conditions were selected. Monte Romero mine tailings showed an upper level mainly composed of silicates and a deeper level mainly composed of sulfides and barite. The toxic metal content was different in both levels but high enough to exceed the regional legal concentration limits for agricultural soils. An electrical resistivity tomography survey revealed a homogeneous upper unit (3 m thickness), which displayed low resistivity values, corresponding to water-saturated silt and clay materials with an abundance of sulfides which was interpreted as the pond infilling. The La Naya mine pond presented a homogeneous mineralogical composition made up of quartz as the main mineral and chlorite-smectite and jarosite as accessory phases. The absence of sulfide phases and the low contents of metal elements are directly related to the reworking processes of the sludge dumped in this pond. The geophysical survey revealed that the pond infilling did not have a constant thickness, but ranged between 15 and 20 m. An inner groundwater flow in the infilling was recognized. The low resistivity values allowed the presence of acid waters and related subsurface flows to be identified in both mine ponds, but no acid water drainage occurred across their vessels. When compared to the Aznalcóllar tailings spill, the La Naya pond is large enough to release a similar amount of sludge, but of a very low metal content. The Monte Romero sludge displays a similar, potentially toxic metal content to the Aznalcóllar sludge, but its size is significantly smaller

A Geochemical and Geophysical Characterization of Sulfide Mine Ponds at the Iberian Pyrite Belt (Spain)

(The original publication is available at www.springerlink.com)This work presents the results of a geochemical and geophysical characterization of the Monte Romero and La Naya mine ponds, belonging to the Cueva de la Mora and Riotinto mine districts, respectively, based on mineralogical, geochemical and geophysical techniques. In order to obtain a representative environmental characterization, two deposits showing different mineralogies, physico-chemical parameters, chemical compositions of tailings and pond conditions were selected. Monte Romero mine tailings showed an upper level mainly composed of silicates and a deeper level mainly composed of sulfides and barite. The toxic metal content was different in both levels but high enough to exceed the regional legal concentration limits for agricultural soils. An electrical resistivity tomography survey revealed a homogeneous upper unit (3 m thickness), which displayed low resistivity values, corresponding to water-saturated silt and clay materials with an abundance of sulfides which was interpreted as the pond infilling. The La Naya mine pond presented a homogeneous mineralogical composition made up of quartz as the main mineral and chlorite-smectite and jarosite as accessory phases. The absence of sulfide phases and the low contents of metal elements are directly related to the reworking processes of the sludge dumped in this pond. The geophysical survey revealed that the pond infilling did not have a constant thickness, but ranged between 15 and 20 m. An inner groundwater flow in the infilling was recognized. The low resistivity values allowed the presence of acid waters and related subsurface flows to be identified in both mine ponds, but no acid water drainage occurred across their vessels. When compared to the Aznalcóllar tailings spill, the La Naya pond is large enough to release a similar amount of sludge, but of a very low metal content. The Monte Romero sludge displays a similar, potentially toxic metal content to the Aznalcóllar sludge, but its size is significantly smaller.Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

Biophysical alterations in lipid rafts from human cerebral cortex associate with increased BACE1/APP interaction in early stages of Alzheimer's disease

In the present study, we have assessed the biophysical properties of lipid rafts from different brain areas in subjects exhibiting early neuropathological stages of Alzheimer's disease (AD). By means of steady-state fluorescence polarization analyses using two environment-sensitive fluorescent probes, we demonstrate that lipid rafts from cerebellum, and frontal and entorhinal cortices, exhibit different biophysical behaviors depending on the stage of the disease. Thus, while membrane anisotropies were similar in the cerebellum along stages, lipid rafts from frontal and entorhinal cortices at AD stages I/II and AD III were significantly more liquid-ordered than in control subjects, both at the aqueous interface and hydrophobic core of the raft membrane. Thermotropic analyses demonstrated the presence of Arrhenius breakpoints between 28.3-32.0 °C, which were not influenced by the disease stage. However, analyses of membrane microviscosity (ηapp) demonstrate that frontal and entorhinal lipid rafts are notably more viscous and liquid-ordered all across the membrane from early stages of the disease. These physicochemical alterations in lipid rafts do not correlate with changes in cholesterol or sphingomyelin levels, but to reduced unsaturation index and increased saturate/polyunsaturated ratios in phospholipid acyl chains. Moreover, we demonstrate that β-secretase/AβPP (amyloid-β protein precursor) interaction and lipid raft microviscosity are strongly, and positively, correlated in AD frontal and entorhinal cortices. These observations strengthens the hypothesis that physical properties of these microdomains modulate the convergence of amyloidogenic machinery toward lipid rafts, and also points to a critical role of polyunsaturated fatty acids in amyloidogenic processing of AβPP

Assessment of precision in dems generated using automatic correlation

En este trabajo se muestra una experiencia en la generación de Modelos Digitales de Elevaciones (MDE) a partir de algoritmos de correlación automática propios de una Estación de Fotogrametría Digital (EFD), así como una evaluación sobre la precisión obtenida en función de los datos disponibles y de la metodología empleada. Este estudio se aplica a un espacio singular denominado cerro “Calderico” en el que se ubican los famosos molinos de viento de Don Quijote en Consuegra (Toledo, España), donde se diferencian tres zonas, caracterizadas principalmente por su distinta pendiente. Una vez creados los diferentes MDE para los ámbitos descritos se efectúa un análisis estadístico que nos servirá para hacer una valoración cuantitativa tanto de los modelos como de las ortoimágenes que se obtengan. Los resultados que se aportan indican mayor disparidad en la precisión de los puntos homólogos identificados en cada MDE para las zonas de más desnivel y menor en las zonas con pendiente más suave. Es interesante observar la buena calidad de los puntos controlados mediante GPS diferencial

Dicyclopentadienyl zirconium and hafnium complexes with the bridged (dimethylsilanodiyl)dicyclopentadienyl [(SiMe2)(η5-C5H4)2]2 ligand. X-ray molecular structure of [Zr{(SiMe2)(η5-C5H4)2}(CH2Ph)]2(μ-O)

Reaction of the bridged (dimethylsilanediyl)dicyclopentadienyl dilithium salt [(SiMe2)(C5H4)2Li2] with MCl4, in toluene, gave the zirconium and hafnium complexes [M{(SiMe2)(η5-C5H4)2}Cl2] [M=Zr (1), Hf (2)]. Addition of two equivalents of M′R (M′=MgCl, R=CH3; M′=Li, R=CH2CMe2Ph; M′=MgBz, R=CH2Ph) to toluene or diethyl ether solutions of [M{(SiMe2)(η5-C5H4)2}Cl2] afforded the dialkyl derivatives [M{(SiMe2)(η5-C5H4)2}R2] [R=CH3, M=Zr (3), Hf (4); R=CH2CMe2Ph, M=Zr (5), Hf (6); R=CH2Ph, M=Zr (7)]. Compound 1 reacted with LiMe and Mg(CH2Ph)2(THF)2 in the presence of a stoichiometric amount of water to give the μ-oxo derivatives [Zr{(SiMe2)(η5-C5H4)2}R]2(μ-O) [R=CH3 (8), CH2Ph (9)]. The X-ray molecular structure of [Zr{(SiMe2)(η5-C5H4)2}(CH2Ph)]2(μ-O) (9) has been determined by diffraction methods. Its most remarkable feature is the planarity of the BzZrOZrBz and the linearity of the ZrOZr systems.We acknowledge the Dirección General de Investigación Científica y Técnica (Spain) for financial support of this research (Project PB97-0776)