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This study examines the feasibility of manufacturing glazed porcelain tiles with a more environmentally friendly manufacturing process, by reducing water and thermal energy consumption. The process studied in this paper is dry milling in a pendulum mill, with subsequent granulation (in order to obtain a press powder with similar flowability to that of spraydried powders). The different morphology of the new granulate with respect to the standard spray-dried granulate modifies the microstructure of the green compacts and thus, their behaviour and fired tile properties. In order to obtain porcelain tiles with the required properties (water absorption, mechanical strength,…) changes have been made in the raw materials mixture and in the processing variables. Finally, porcelain tiles measuring 50x50 cm have been manufactured at industrial scale with the new granulate using a conventional firing cycle, obtaining quality levels identical to those provided by the spray-dried granulate. These results open the possibility of preparing porcelain tile body compositions through a manufacturing process alternative to the standard one, more environmentally friendly and with lower costs.En el presente trabajo se ha estudiado la viabilidad de fabricar gres porcelánico esmaltado utilizando un sistema de preparación de la composición del soporte más respetuoso con el medio ambiente, lo que implica una reducción importante de los consumos de agua y de energía térmica. El proceso que se estudia en el presente trabajo es el consistente en la molienda vía seca en molino pendular y en la posterior granulación (para obtener un polvo de prensas con fluidez similar a la de los polvos atomizados). La distinta morfología de los nuevos gránulos obtenidos respecto al polvo atomizado actual, modifica la microestuctura en crudo de las piezas y, con ello, el comportamiento y propiedades finales de las baldosas obtenidas. Por ello, ha sido necesario modificar la mezcla de materias primas y ajustar algunas variables de operación para obtener baldosas de gres porcelánico con las propiedades requeridas (absorción de agua, resistencia mecánica, etc.). Finalmente, se han fabricado industrialmente piezas de gres porcelánico (50x50 cm2) con el nuevo granulado, mediante un ciclo de cocción convencional, obteniendo unos niveles de calidad idénticos a los que proporciona el polvo atomizado. Estos resultados abren la posibilidad de preparar las composiciones de soporte de gres porcelánico mediante un sistema alternativo al actual, más respetuoso con el medio ambiente y con un menor coste.

Abstract Numerous genetic studies have contributed to reconstructing the human history of the Canary Islands population. The recent use of new ancient DNA targeted enrichment and next-generation sequencing techniques on new Canary Islands samples have greatly improved these molecular results. However, the bulk of the available data is still provided by the classic mitochondrial DNA phylogenetic and phylogeographic studies carried out on the indigenous, historical, and extant human populations of the Canary Islands. In the present study, making use of all the accumulated mitochondrial information, the existence of DNA contamination and archaeological sample misidentification in those samples is evidenced. Following a thorough review of these cases, the new phylogeographic analysis revealed the existence of a heterogeneous indigenous Canarian population, asymmetrically distributed across the various islands, which most likely descended from a unique mainland settlement. These new results and new proposed coalescent ages are compatible with a Roman-mediated arrival driven by the exploitation of the purple dye manufacture in the Canary Islands.

The synthesis of materials of high added value from a natural kaolin has been studied. The kaolin was pre-activated by means of calcination to obtain the metakaolins, which are amorphous solids capable of being modified by simple and non expensive chemical treatments. These solids were then submitted to acid and basic treatments to modify their structure and properties. The acid activation under specific conditions gave place to the synthesis of solids mainly constituted by silica with good textural properties, developing so much their external and internal surface, these solids may be used like adsorbentes and catalytic supports. On the other hand, the basic activation produced the modification of the metakaolins and it gave place to the crystallisation of the zeolite K-F (Z), appearing as a simple and effective method for the synthesis of this material.En este trabajo se ha estudiado la síntesis de materiales de alto valor añadido a partir de un caolín natural. Para ello el caolín fue pre-activado mediante calcinación para dar lugar a la formación de metacaolines, sólidos amorfos susceptibles de ser modificados por tratamientos químicos de una manera sencilla y poco costosa. Estos sólidos fueron posteriormente sometidos a tratamientos ácidos y básicos para modificar su estructura y propiedades. La activación ácida bajo unas condiciones específicas dio lugar a la síntesis de sólidos constituidos mayoritariamente por sílice con buenas propiedades superficiales, desarrollándose tanto su superficie externa como interna, revelándose como sólidos que pueden ser empleados como adsorbentes y soportes catalíticos. Por su parte, la modificación causada por la activación básica dio lugar a la cristalización de la zeolita K-F (Z), presentándose como un método sencillo y eficaz para la síntesis de este material.

The Albufera is recognised as Natural Park by Generalitat Valenciana decree of 8´th July 1989 and is listed on the wet areas of international importance of the Ramsar Conference since 8´th May 1990. Batimetry studies show the gradual full up of the lake. If the stuffing and pollution process persist, lamentably, in order to preserve the lake identity it will be necessary to extract the sediments which must be environmental adequately managed. In this study the ceramic characteristics of the Albufera of Valencia sediments have been analysed in order to know the possibility of their use as ceramic raw material or as additive to ceramic stoneware of the valencian tile industry.El lago de la Albufera es Parque Natural por decreto de 8 de Julio de 1989 de la Generalitat Valenciana y está desde el 8 de Mayo de 1990 en el listado de Zonas Húmedas de importancia internacional de la Conferencia de Ramsar. Los estudios de batimetría del lago indican que el lago continúa su proceso lento de colmatación, Si el proceso de colmatación y contaminación persevera o se inducen severas contaminaciones locales por vertidos, es posible que lamentablemente, para preservar la identidad del sistema, sea necesario dragar el lago de forma selectiva y cuidadosa siendo necesario dar un fin último a los fangos obtenidos. En este estudio se analizan las características de los sedimentos de la Albufera de Valencia desde el punto de vista cerámico, con el fin de Conocer las posibles utilizaciones de los mismos para la producción de algún tipo de cerámica o como componentes de adición a pastas cerámicas de la industria azulejera Valenciana.

Industrial wastes produced by the ceramic pigment industry have been characterized according to chemical and ecotoxicity overview and classified as “Dangerous or Not Dangerous” waste with regard to environmental Spanish Law. Analysis carried out on wastes comming from an industrial pecipitation-sedimentation process indicate that such wastes do not exceed any of the environmental limits checked, if only colorant ions are present; however the industrial practice often give rise to enamel wastes wich present Pb and B levels exceeding legal limits.En el presente trabajo se han caracterizado los residuos generados por la industria de pigmentos cerámicos, desde un punto de vista tanto químico como atendiendo a su ecotoxicidad, clasificándolos después como "Peligrosos o No peligrosos" de acuerdo a la legislación española. Así, los análisis realizados a residuos procedentes del proceso de depuración industrial de precipitación-decantación, indican que tales residuos no superan las concentraciones limite establecidas para ninguno de los contaminantes estudiados, si la componente de estos residuos es únicamente debida a residuos de colorantes. Sin embargo, la práctica habitual tiende a mezclar estos residuos con los de procedencia de esmaltes, que a menudo presentan concentraciones de Pb y B que superan los límites legales.

The texture development of a saponite and a montmorillonite, intercalated with zirconium and aluminium oligomers, after calcination at 500 ºC has been studied. Remarkable differences were observed among samples, depending on the source of the intercalating polycations and the parent material. On calcining, the alumina pillared clays suffered noticeable specific surface area and micropore volume losses, which have been related to the interlayer and interpillar distances of the samples. On the contrary, the zirconia pillared clays showed a slight surface area increase, which affected both micropores and mesopores and could be due to the combined effect of the thermal decomposition of the zirconium oligomers and the possible presence of mesoporous ZrO2 particles.En este trabajo se ha estudiado la evolución de las propiedades texturales de una saponita y una montmorillonita intercaladas con disoluciones de circonio y aluminio tras calcinación a 500 ºC. Los sólidos presentaron un diferente comportamiento en función de la naturaleza de la disolución de intercalación y de la arcilla empleada. Tras calcinación, la superficie específica y el volumen microporoso de las arcillas intercaladas con disoluciones de aluminio disminuyeron de manera importante, lo cual se ha relacionado con las distancias interlaminar e interpilar que presentaron los materiales intercalados. Por contra, las superficies específicas de las arcillas intercaladas con disoluciones de circonio aumentaron, probablemente gracias al efecto combinado de la descomposición térmica de los ligandos orgánicos unidos al circonio en los policationes y la posible presencia de partículas mesoporosas de ZrO2 sobre la superficie de los sólidos.

Heteromorphic pigments present the chromophore particle occluded in an encapsulating matrix which is thermally stable and insoluble in glazes. The occluded chromophore compound is also insoluble in the host matrix. In this work the mechanisms of formation of this type of pigments are analyzed and the occlusion of hematite into silica matrix is discussed. The formation of this hematite-silica red pigment follows a sintering-coarsening mechanism, and, consequently, the control of both hematite particles nucleation and their crystal growth results to be decisive to obtain a good coloring effectiveness.En los pigmentos heteromórficos la partícula de cromóforo es ocluida en una matriz encapsuladora estable tanto termicamente como frente a los vidriados. El compuesto cromóforo ocluido y la matriz no coloreada son insolubles. En este trabajo se analiza los diferentes mecanismos de formación de estos pigmentos heteromórficos y se estudia la oclusión de hematita en sílice mediante métodos sol-gel acuoso. El pigmento sigue un mecanismo de sinterización-crecimiento cristalino por lo que es muy importante controlar el momento de nucleación y la velocidad de crecimiento de las partículas de hematita en el seno de la matriz.

The synthesis of nanostructured Mg-FSZ fully stabized zirconia by chemical methods such as colloidal gel, polyester resin and hydrolisis of alkoxides has been studied. The addition of praseodymium ion facilitates cubic stabilization avoiding the Mg- FSZ partitioning with temperature. Praseodymium improve the ionic conductivity of the material probably by the entrance of Pr3+ on the host lattice substitting Zr4+ and subsequently introduction of additional oxygen vacancies trapped near the zirconium ion.En este trabajo se estudia la obtención de circona cúbica estabilizada con magnesio nanoestructurada por métodos químicos tales como el gel coloidal, resina poliester de citrato así como hidrólisis de alcóxidos. La adición de praseodimio mejora la reactividad del sistema y evita la transformación a monoclínica con la temperatura. Asimismo el praseodimio mejora la conductividad iónica del material por un mecanismo de disolución sólida de modo que el Pr3+ introduce nuevas vacantes de oxígeno que podrían quedar asociadas a iones circonio en la red.

Despite the worldwide importance of disease complexes involving root-feeding nematodes and soilborne fungi, there have been few in-depth studies on how these organisms interact at the molecular level. Previous studies of guava decline have shown that root exudates from Meloidogyne enterolobii-parasitized guava plants (NP plants), but not from nematode-free plants (NF plants), enable the fungus Neocosmospora falciformis to rot guava roots, leading to plant death. To further characterize this interaction, NP and NF root exudates were lyophilized; extracted with distinct solvents; quantified regarding amino acids, soluble carbohydrates, sucrose, phenols, and alkaloids; and submitted to a bioassay to determine their ability to enable N. falciformis to rot the guava seedlings’ roots. NP root exudates were richer than NF root exudates in amino acids, carbohydrates, and sucrose. Only the fractions NP-03 and NP-04 enabled fungal root rotting. NP-03 was then sequentially fractionated through chromatographic silica columns. At each step, the main fractions were reassessed in bioassay. The final fraction that enabled fungal root rotting was submitted to analysis using high performance liquid chromatography, nuclear magnetic resonance, mass spectrometry, energy-dispersive X-ray fluorescence, and computational calculations, leading to the identification of 1,5-dinitrobiuret as the predominant substance. In conclusion, parasitism by M. enterolobii causes an enrichment of guava root exudates that likely favors microorganisms capable of producing 1,5-dinitrobiuret in the rhizosphere. The accumulation of biuret, a known phytotoxic substance, possibly hampers root physiology and the innate immunity of guava to N. falciformis.

Abstract The introgression of M. enterolobii resistance-related genes in guava breeding programs can be compromised by incompatibility among Psidium species. This study aimed to evaluate the female parent preference and genetic diversity of Psidium interspecific hybrids using morphoagronomic traits and resistance to M. enterolobii. There were evaluated cross successes and germination from crosses between accesses of P. cattleyanum, P. guineense and P. guajava and the genetic diversity by Ward-MLM method of hybrids according to descriptors developed for the genus. Crosses were more successful when P. cattleyanum was the female parent. Germination was more successful in crosses involving P. cattleyanum and P. guajava. Four groups were formed. The group IV clustered the most resistant genotypes, composed by genotypes of P. cattleyanum x P. guineense, while the group II was the most susceptible. The groups I and III grouped some genotypes of P. cattleyanum x P. guajava with low levels of susceptibility. There are preferences of female parent species among crosses. Some individuals of groups I and III can be used as source of resistance genes for the breeding program, due the presence of favorable alleles inherited from guava parent. The high susceptibility leads to reduction in root development.

The Canary Islands' indigenous people have been the subject of substantial archaeological, anthropological, linguistic and genetic research pointing to a most probable North African Berber source. However, neither agreement about the exact point of origin nor a model for the indigenous colonization of the islands has been established. To shed light on these questions, we analyzed 48 ancient mitogenomes from 25 archaeological sites from the seven main islands. Most lineages observed in the ancient samples have a Mediterranean distribution, and belong to lineages associated with the Neolithic expansion in the Near East and Europe (T2c, J2a, X3a…). This phylogeographic analysis of Canarian ancient mitogenomes, the first of its kind, shows that some lineages are restricted to Central North Africa (H1cf, J2a2d and T2c1d3), while others have a wider distribution, including both West and Central North Africa, and, in some cases, Europe and the Near East (U6a1a1, U6a7a1, U6b, X3a, U6c1). In addition, we identify four new Canarian-specific lineages (H1e1a9, H4a1e, J2a2d1a and L3b1a12) whose coalescence dates correlate with the estimated time for the colonization of the islands (1st millennia CE). Additionally, we observe an asymmetrical distribution of mtDNA haplogroups in the ancient population, with certain haplogroups appearing more frequently in the islands closer to the continent. This reinforces results based on modern mtDNA and Y-chromosome data, and archaeological evidence suggesting the existence of two distinct migrations. Comparisons between insular populations show that some populations had high genetic diversity, while others were probably affected by genetic drift and/or bottlenecks. In spite of observing interinsular differences in the survival of indigenous lineages, modern populations, with the sole exception of La Gomera, are homogenous across the islands, supporting the theory of extensive human mobility after the European conquest.

El valle de Salientes (norte de León, España) es un área situada inmediatamente al sur del eje principal de la Cordillera Cantábrica, de la que se halla relativamente aislada debido a los procesos erosivos producidos entre las cabeceras de los ríos Sil y Luna. Este hecho histórico/geológico convierte a este valle en un enclave muy singular y a su biota en un interesante objetivo de estudio. Este trabajo, con un enfoque faunístico, aporta información sobre Carabidae (Insecta, Coleoptera) que habitan en esta área. Se realizaron cuatro campañas entomológicas en tres años consecutivos, donde se recogieron 1255 especímenes, pertenecientes a 101 especies, en 61 puntos de muestreo, mediante captura activa e instalación de trampas pitfall. Los resultados revelan que, en términos de diversidad específica y abundancia, la mayoría de los ejemplares pertenecen a la subfamilia Harpalinae, teniendo especial relevancia Harpalini (18 spp, 167 exx), Zabrini (11 spp, 55 exx), Pterostichini (10 spp, 200 exx), Sphodrini (9 spp, 150 exx) y Platynini (6 spp, 83 exx). Además, se realizó un análisis biogeográfico que puso de manifiesto la elevada contribución que hacen los endemismos ibéricos en la composición faunística de los Carabidae de este enclave geográfico. Finalmente, se discuten aspectos taxonómicos de algunas especies colectadas: 1) el caso de Trechus (Trechus) suturalis Putzeys, 1870 y Trechus (Trechus) gallaecus Jeannel, 1921, cuya morfologíadel edeago, ilustrada en este trabajo, es clave para la distinción inequívoca de ambas especies; 2) también se pone de manifiesto la gran variabilidad observada respecto a los caracteres externos de dos especies ibéricas de Oreophilus Chaudoir, 1838, Pterostichus (O.) cantaber (Chaudoir, 1868) y Pterostichus (O.) franzi Nègre, 1955, concluyendo que no son lo suficientemente consistentes, teniendo que recurrir a la morfología del edeago como único carácter totalmente fiable para identificar ambas especies. Además, se aportan comentarios en relación con la autoecología y preferencia de hábitat (áreas forestales, riparias/palustres, ruderales y subterráneas) de las especies más representativas. Por último, se amplía el rango de distribución del microendemismo Trechus teverganus Toribio, 2015, a pesar de las aparentes barreras geográficas y geológicas que podrían existir para esta especie de vida subterránea.

Summary: The conquest of the Canary Islands by Europeans began at the beginning of the 15th century and culminated in 1496 with the surrender of the aborigines. The collapse of the aboriginal population during the conquest and the arrival of settlers caused a drastic change in the demographic composition of the archipelago. To shed light on this historical process, we analyzed 896 mitogenomes of current inhabitants from the seven main islands. Our findings confirm the continuity of aboriginal maternal contributions and the persistence of their genetic footprints in the current population, even at higher levels (>60% on average) than previously evidenced. Moreover, the age estimates for most autochthonous founder lineages support a first aboriginal arrival to the islands at the beginning of the first millennium. We also revealed for the first time that the main recognizable genetic influences from Europe are from Portuguese and Galicians.