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This research focuses on the potential for microbial treatment to stabilize compacted soils, which are often utilized in earthwork projects. A silt–clay sand was used to describe a particular kind of soil. The suggested remedy makes use of the soil’s naturally occurring urea and Ca2+, as well as microorganisms introduced to the compaction water. Two alternative initial water-content types were examined: those on the dry side and those close to the ideal Proctor conditions. Bacillaceae microorganisms were used to induce microbial CaCO3 precipitation and improve the hydraulic and mechanical properties of the compacted soil. The samples were biotreated and immediately compacted, so that the precipitation of calcium carbonate during the curing process took place in the contact areas between the particles (biocementation) and in the pore space (bioclogging). A set of techniques were used to study the ageing effects, such as the water-retention curve by dew-points psychrometer, mercury porosimetry intrusion, permeability, ultrasonic pulse velocity, resonant column, and unconfined and tensile-compression tests. During the ageing, it was observed that the bacterial activity consumed water for the hydrolysis of urea and other intermediate reactions to precipitate CaCO3. This process resulted in a retraction of the microstructure and a change in the macrostructure. The bioclogging phenomenon was more evident in the soil microstructure, while the biocementation process was easier to observe in the macrostructure. The suction’s effects on the soil stiffness were studied in detail, and a significant increase was detected. Despite these water-content losses, which caused soil stiffening by increasing the suction, it was still feasible to identify the gradual rise in small-strain stiffness throughout incubation. The unconfined and tensile-compression tests showed a similar progressive increase in terms of peak compressive and peak splitting strength during the incubation. These re

The influence of firing temperature on the ceramic properties of illite-chlorite-calcitic clays has been investigated. Three samples of the same clay deposit have been selected. Weight loss, dimensional changes, water absorption, bulk density, open porosity, flexural and compressive strengths, initial capillary water absorption rate and thermal conductivity have been determined as a function of firing temperature in the range 900-1200 °C with 1 h of soaking time. The microstructures of the fired samples have been examined by SEM and the phase evolution studied by XRD. The water absorption capacity decreased from ∼ 22% at 900 °C/1 h to a maximum of 12% at 1200 °C/1 h with a maximum linear shrinkage of ∼ 2.7%. The open porosities decreased from ∼ 36% at 900 °C/1 h up to ∼ 20% at 1200 °C/1 h as an effect of progressive sintering with higher densification degree of the ceramic bodies. The flexural strength reached a maximum value of ∼ 34 MPa at 1200 °C/1 h. In contrast, the compressive strengths increased by firing up to a maximum of ∼ 114 MPa at 1200 °C/1 h. The thermal conductivity increased slightly as increasing firing temperature with a maximum value of 0.582 W/m·K in samples fired at 1200 °C/1 h. The Ryshkevitch-Duckworth equation was applied and the results indicated that compressive strength is related linearly with open porosity. A linear correlation was found between thermal conductivity and open porosity. The microstructural evolution by SEM indicated that there is a change of the fired samples at 1100 °C as compared to SEM observations at 900 and 1000 °C. There is an increase of contacts between particles and layered structures associated to dehydroxylated clay minerals (illite and chlorite), quartz particles and pores developed by firing. At 1200 °C/1 h, the microstructures have changed associated to the higher degree of vitrification in the fired sample, with consolidation of the material, interparticle and neck contacts with formation of vitrified bridges

[ES] Procedimiento de preparación de materiales cerámicos que contienen forsterita (ortosilicato de magnesio) a partir de un silicato laminar hidroxilado, de preferencia talco, que comprende mezclar una suspensión acuosa del silicato laminar hidroxilado con óxido de magnesio, secar la suspensión obtenida anteriormente a una temperatura de hasta 350 °C y el producto secado someterlo a un tratamiento mecanoquímico por activación mecánica en molino de bolas durante un tiempo de entre 0 y 40 horas, seguido de una etapa de tratamiento térmico de hasta 1200 ºC durante un tiempo comprendido entre 60 y 150 minutos. Además, la invención se refiere a un material cerámico obtenible por el procedimiento descrito que comprende forsterita en proporción del 90-95 % en peso del material cerámico y a sus aplicaciones como material refractan o básico o biocerámico., [EN] Process for preparing ceramic materials containing forsterite (magnesium orthosilicate) from a hydroxylated layered silicate, preferably talc, comprising mixing an aqueous suspension of the hydroxylated layered silicate with magnesium oxide, drying the suspension obtained previously at a temperature of up to 350 °C and subject the dried product to a mechanochemical treatment by mechanical activation in a ball mill for between 0 and 40 hours, followed by a heat treatment stage up to 1200 °C for between 60 and 150 hours. minutes. In addition, the invention relates to a ceramic material obtainable by the described process that comprises forsterite in a proportion of 90-95% by weight of the ceramic material and its applications as a refractory or basic or bioceramic material.

The present work is a review concerning the previous investigations on the vitrification behaviour of clays containing kaolinite, feldspars, muscovite (illite/sericite) and pyrophyllite. These clays are silico-aluminous and have interesting properties as raw materials for structural ceramics. The mineralogical and chemical composition were determined. Then, the vitrification in these clay samples using pressed bodies was investigated by few researchers in the temperature range 800 - 1350 ºC with 0.5 - 5.5 h of soaking times. The effect of heat treatments on the degree of vitrification in these clays was characterized by bulk densities of the ceramic bodies at the fired stage. It was found some variations of bulk density values for all these clays fired in the range 1000- 1150 ºC, with marked decreases of the values obtained at 1200 ºC and 1300 ºC. A first order reaction kinetics was applied to the analysis of vitrification of the ceramic bodies under isothermal heating. The method is based on experimental data of bulk densities, being proposed for the estimation of the relative degree of vitrification resulting from different firing schedules. The analysis considered the temperature dependence of the rate of vitrification following Arrhenius behaviour. Thus, the vitrification activation energy can be obtained. The activation energies for the physical process of vitrification in these clays ranged from 45 to 151 kJ/mol. The relative rates of vitrification or degree of vitrification attained during heating and soaking were calculated. The results suggested that the contribution of vitrification due to heating in all these clays was relatively small compared to the vitrification during soaking. However, it was evidenced that the influence of the particle sizes in the thermal behaviour of these clays cannot be neglected. The vitrification rate equations, as deduced in these previous studies, can be useful tools to estimate the optimum firing conditions of these clays, a

El presente trabajo aporta una investigación arqueométrica sobre piezas cerámicas de los siglos III-I a. C. halladas en contextos alfareros de la ciudad de Sevilla (Palacio Arzobispal)y Carmona (zona del Arrabal), pertenecientes en su mayoría a ánforas de tradición púnica y turdetana, o bien ya romanizadas. Entre los principales objetivos se ha pretendido su caracterización tecnológica y composicional, la comparación de las características de cada tradición productiva y la confirmación de la posible procedencia local de estas producciones. En total, han sido 13 las muestras estudiadas con análisis petrográfico de láminas delgadas, análisis químico mediante fluorescencia de rayos X y análisis mineralógico por difracción de rayos X. Los resultados químicos muestran su carácter sílicoaluminoso y cálcico, con contenidos variables de óxido de hierro, así como otros elementos minoritarios y trazas. El tratamiento estadístico ha diferenciado 3 conglomerados y una muestra que se distingue del resto. El análisis mineralógico ha identificado 8 fases cristalinas, unas ya presentes en las materias primas y otras formadas por tratamiento térmico. Destacan la illita, identificada como fase deshidroxilada, anortita, diópsido y gehlenita. En cuanto al análisis petrográfico, se han identificado tres grupos petrográficos que se corresponden composicionalmente con el contexto de origen de las muestras, diferenciando entre las pie-zas procedentes de Sevilla, las formas romanizadas de Carmona y la cerámica común y formas de imitación de este mismo enclave., The present work consists of an archaeometric investigation concerning ceramic samples, mostly unpublished, of the III-I centuries b.C. They were found in connection with kilns of the city of Sevilla (Archbishop's Palace) and the countryside (Arrabal zone, Carmona). They are identified with evolved variations of Iron Age amphorae of Punic and Turdetanian tradition, or already Roman typologies. The main objectives of this research include their technological and compositional characterization as well as the comparison of the characteristics of each manufacture tradition. An assemblage of 13 samples has been studied through petrographic analysis of thin sections, chemical analysis (X-ray fluorescence) and mineralogical analysis (X-ray diffraction). The chemical results showed the silico-aluminous and calcitic character of the samples, with variable contents of iron oxide as well as other minor elements and traces. The statistical treatment of the data by multivariant analysis has differentiated 3 conglomerates and one sample as an outsider. The mineralogical analysis has identified 8 crystalline phases, several of them already present in the raw materials and others formed by thermal treatment. It is interesting to note the illite, identified as dehydroxylated phase, anorthite, diopside and gehlenite. The petrographical analysis has identified 3 different petro-groups, which are correlated by a compositional point of view with the original context of the samples. Thus, according to these results, it has been possible to distinguish the manufactures of Sevilla from the Roman shapes, the common ware and the imitation types of Carmona. It has been discussed the possible solid-state reactions which yielded the crystalline phases identified by X-ray diffraction, besides an estimation of firing temperatures between 820-850 °C in an oxidant atmosphere. Finally, the possible sources for the raw materials used in the fabrication of these amphorae have been proposed in the Guad

[ES] El objeto de la invención es un procedimiento de utilización de polvo de filtro residual de la industria del aluminio para la obtención de espumas rígidas geopoliméricas, así como los materiales obtenidos y usos de los mismos. Mediante el procedimiento de la invención se consigue la obtención de espumas rígidas que precisamente aprovechan esta característica de alta porosidad para sus aplicaciones. El empleo de polvo de filtros residuales de la industria secundaria del aluminio posee ventajas importantes respecto al estado de la técnica. El subproducto al igual que las cenizas de cáscara de arroz se presentan en polvo con tamaño de partícula adecuado para la síntesis de la espuma rígida geopolímérica., [EN] The object of the invention is a process for the use of residual filter dust from the aluminum industry to obtain rigid geopolymeric foams, as well as the materials obtained and uses thereof. By means of the process of the invention, it is possible to obtain rigid foams that precisely take advantage of this characteristic of high porosity for their applications. The use of residual filter dust from the secondary aluminum industry has important advantages over the state of the art. The by-product, as well as the rice husk ash, is presented in powder with a suitable particle size for the synthesis of the rigid geopolymeric foam.

In this research, the use of olive pomacefly ash(OPFA) as an alkaline source for the activationof calcined clays (CC) from Bail en (Ja en, Spain) was studied. The optimal composition was obtained for 70 wt % CC and 30 wt % OPFA. The physical,mechanical and thermal properties of control geopolymers that usewater as a liquidmediumhave been studied and comparedwith geopolymers that use additional activating solutions as sodiumor potassiumhydroxide solutions (8M), or amixture of alkaline hydroxide and alkaline silicate solution (NaOHeNa2SiO3 or KOHeK2SiO3). The results showed that OPFA can be used as an alkaline activator, showing mechanical properties slightly lower than those obtained when additional alkaline hydroxide activating solutions were used. The best compressive strength was obtained for geopolymers that use alkaline silicates as an activating solution. However, the best thermal insulation properties were obtained for control geopolymers. The microstructural characteristics of the geopolymers were evaluated by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and Scanning ElectronMicroscopy (SEM-EDS) that corroborate the formationof geopolymeric gel inall the specimens, beingthe amount of gel formed greater insamples using commercial potassiumactivating solutions. These results demonstrate the feasibility of using this type of waste, OPFA, as activating reagents in the manufacture of geopolymers or alkaline activated materials. The manufactured geopolymers can be used as compressed earth blocks for walls and partitions, since the specimens pursue mechanical properties that comply with current regulations, presenting better thermal insulation properties.

The sintering behaviour of a pyrophyllite clay has been investigated. The mineralogical composition by X-ray diffraction (XRD) of this sample was ∼35 wt.% pyrophyllite, ∼25 wt.% sericite/illite, ∼15 wt.% kaolinite and ∼20 wt.% quartz. The chemical composition was consistent with these results, with a total flux content of 4.18 wt.%. Prismatic bars were prepared by dry pressing using this sample and fired in the range 800–1500 °C with 0.5–5 h of soaking times. Sintering diagrams were obtained using the results of linear firing shrinkage, water absorption capacity, bulk density and apparent porosity determined in the ceramic bodies as a function of firing temperatures. It was found a trend of slight variations of bulk density values firing in the range 1000–1150 °C, with marked decreases of these values for these bodies fired at 1200 °C and 1300 °C. The temperature of maximum bulk density was determined as ∼1200 °C and the vitrification temperature was ∼1300 °C where the apparent porosity becomes almost zero. The vitrification process of the pyrophyllite clay sample was investigated using a method previously described in the literature, which considered an Arrhenius approach under isothermal conditions and a first order kinetic. It was determined an activation energy (Ea) of ∼45 kJ/mol with a linear correlation coefficient of 0.998. The relative rates of vitrification were calculated. It was found that the contribution of vitrification due to the heating was relatively small compared to the vitrification during soaking. Mullite and quartz are forming the ceramic bodies besides a vitreous or glassy phase. The thermally treated pyrophyllite clay showed a dense network of rod-shaped and elongated needle-like crystals, being characteristic features of mullite as a dense felt. The vitrification rate equation, as deduced in this study by first time, can be a useful tool to estimate the optimum firing conditions of the pyrophyllite clays applied as ceramic raw materials., En el presente trabajo se ha estudiado el comportamiento de sinterización de una arcilla con pirofilita que posee una composición mineralógica (% en peso), deducida por difracción de rayos X, de ∼35% de pirofilita, ∼25% de sericita/illita, ∼15% de caolinita y ∼20% de cuarzo. La composición química fue consistente con estos resultados y mostró un contenido total de fundentes de 4,18% en peso. Se prepararon probetas conformadas como barras prismáticas mediante prensado uniaxial, en seco, de la muestra original para estudiar su comportamiento en cuanto a sinterización en el intervalo de temperaturas 800-1.500 °C, con tiempos de permanencia desde 0,5 a 5 h. Se obtuvieron los diagramas de sinterización utilizando los resultados de contracción lineal por cocción, capacidad de absorción de agua, densidad y porosidad aparente determinadas en las probetas tratadas térmicamente en función de la temperatura. Se ha encontrado una tendencia a presentar variaciones no muy importantes de los valores de densidad de las probetas cerámicas en el intervalo 1.000-1.150 °C, con un marcado descenso de estos valores cuando se trataron térmicamente a 1.200 °C y 1.300 °C. La temperatura del máximo de densidad se produce a ∼1.200 °C y la temperatura de vitrificación ∼1.300 °C, a la cual la porosidad aparente llega a alcanzar valores casi nulos. El proceso de vitrificación de esta arcilla con pirofilita se ha investigado utilizando una metodología descrita en la bibliografía que considera una aproximación de tipo Arrhenius, bajo condiciones isotérmicas, y una cinética de primer orden. Con la aplicación de dicha metodología se determinó una energía de activación Ea ∼ 45 kJ/mol y un coeficiente de correlación lineal de 0,998. Se calcularon las velocidades relativas de vitrificación durante el tiempo de permanencia a varias temperaturas. Con la realización de este análisis se encontró que la contribución de la vitrificación debida al tratamiento térmico es relativamente pequeña comparada con la

The main objective of this investigation is to study the effect of the substitution of metakaolin (MK) (from calcined industrial kaolin) by four different calcined natural Southern Spain clays traditionally used in the brick and tile sector, as well as by the biomass bottom ash residue (BBA) from the combustion of a mix of olive and pine pruning on the synthesis of geopolymer with physical, mechanical and thermal properties comparable to those of classic construction materials. As alkaline activator, a 8 M solution of sodium hydroxide and sodium silicate have been used. Raw materials, metakaolin; Spanish clays: black clay (BC), yellow clay (YC), white clay (WC), red clay (RC) and BBA were characterized by chemical analysis (XRF), mineralogical analysis (XRD), and particle size analysis. Control geopolymers containing only metakaolin, and batch of geopolymers were formulated containing equal proportions of metakaolin, BBA and each of the four types of clay. After the curing period, at 60 °C for 1 day geopolymers were demolded and stored 27 days at room temperature. Geopolymers were characterized using Scanning Electron Microscopy coupled with Energy Dispersive Spectroscopy (SEM-EDS), XRD and Attenuated Total Reflectance- Fourier Transform Infrared Spectroscopy (ATR-FTIR). Their physical, mechanical and thermal properties have also been studied. The addition of BBA and different types of calcined clays to metakaolin gives rise to geopolymers with higher mechanical properties increasing the compressive strength of the control geopolymer containing only MK (24.9 MPa) by more than 50% for the GMK-BBA-WC geopolymers (38.5 MPa). The clays act as fillers and/or promote the precipitation of calcium-rich phases (Ca)-A-S-H-G gel that coexists with the (Na)-A-S-H gel type. The relevant results of physical, mechanical and thermal properties obtained in this research demonstrate the potential of Spanish clays and BBA as binders and substitutes for metakaolin.

This paper describes the use of industrial wastes arising from different production processes of the ceramic and marble industries as raw materials for the design and formulation of new cement clinkers with a high content of dicalcium silicate (Belite). The aim was to reintroduce these wastes in the industrial sector and take advantage of them for a greater environmental benefit, as indicated by the principles of the circular economy. Formulations containing 2.5, 5 and 10 wt% of chamotte and marble sludge, respectively, and a waste‐free formulation have been designed to obtain clinkers with a content of dicalcium silicate higher than 60 wt%. The different blends have been studied up to a maximum temperature of 1390°C by Thermal Analysis. Other techniques such as XRD, XRF, Modified Bogue Equation, Quality Indexes (LSF, AM, SM) and Optical Microscopy have been used for the study and characterization of industrial wastes, the raw materials and the high belite‐type cement dosages. The results indicate that this type of cements can be designed using different types of wastes and in this way reduce the environmental impacts caused by the extraction of raw materials and the deposition of the wastes in landfills, improving the circular economy of the construction industry.

The objective of the present study is to develop a biotechnological tool for a new application of silty sand soil as stabilized materials in linear works replacing chemical stabilizer (e.g. cement and lime) by natural cement, formed by precipitated calcium carbonate generated by microorganisms of the Sporosarcina family. For this purpose, it is conducted a chemical and mineralogical characterization and an examination of physical and geotechnical properties, being very important from the engineering standpoint. The results of different tests are presented here. The data show that the effects of bacteria are reducing the soil specific surface and increasing its plasticity. The reason for this result could be the addition of a plastic component to the natural soil, or the result of the more aggregated structure promoted during the treatment. The pore size distribution of the soil changes in an approximate range 3 - 30 µm, where the pore mode tends to disappear. The change in the pore density function is reflected in the mechanical behaviour of the treated soil, which presents typical features of a less dense soil with respect to the natural untreated one. The friction angle of the treated soil is slightly higher, and its compressibility is consistently lower than that of the natural soil. As the bacteria do not seem to produce any cementation effect on the soil skeleton, collapse upon wetting does not seem to be significantly affected by the treatment. On the contrary, comparison of collapse data shows that occurrence and amount of collapse are ruled by the as-compacted dry density. The tests performed seem to suggest that the microbiological technique may be effective to improve the mechanical characteristics of the compacted soil. For that, it is necessary to provide more energy in compacting the treated soil that it will be stabilized, so as to achieve a high initial dry density. From this viewpoint, it seems that higher compaction effort is even more effective tha, Postprint (published version)

In this work, the use of waste dust filter of secondary aluminum industry (DFA) to obtain geopolymer foams has been studied. The waste was used as source of alumina and foaming agent. As precursor and principal reactive silica supplier rice husk ash was used. Precursors were chemically activated by means of a sodium hydroxide aqueous solution and a commercial sodium silicate solution. The influence of the DFA content or Si/Al molar ratio (4–7) were determined by keeping the Si/Na molar ratio of 0.7 M constant and the concentration of sodium hydroxide in the activating solution equal to 8.5 M. The geopolymer foams obtained were studied by X-ray Diffraction (XRD), adsorption/desorption of nitrogen, infrared spectroscopy (FTIR), and scanning electron microscope (SEM) techniques. The results indicated that geopolymer foams presented low values of bulk density (643–737 kg/m3) high values of apparent porosity (62–70%), low, but sufficient values of compressive strength (0.5–1.7 MPa) and good values of thermal conductivity (0.131–0.157 W/mK). Lower values of thermal conductivity were obtained for Si/Al = 4 and 5 M ratios, due to the highest apparent porosity and the highest total pore volume. These geopolymer foam materials have similar properties to other construction materials sector such as gypsum boards, foamed concrete, or insulating materials. In addition, its use in other applications of interest such as catalyst support or gas filtration materials could be investigated.

En educación artística cada vez es más imprescindible y necesario establecer una colaboración entre profesionales de distintas disciplinas y áreas de conocimiento para enfocar determinados problemas desde diversos planteamientos y puntos de vista complementarios, conjugar conceptos de las distintas disciplinas y proponer metodologías en cooperación para llevar a cabo dentro de un equipo de tal modo que sea beneficioso para todos. De ahí el concepto de interdisciplinariedad como conjunto de disciplinas conexas entre sí y con relaciones definidas a fin de que sus actividades no se produzcan en forma aislada, dispersa y fraccionada.

The objective of the present study is to develop a biotechnological tool for a new application of clay phyllites as stabilized materials in linear works replacing chemical stabilizer (e.g. cement or lime) by natural cement, formed by precipitated calcium carbonate generated by microorganisms of the Bacillaceae family (Bacillus pasteurii). Part of the development process conducting a chemical and mineralogical characterization and an examination of physical and hydromechanical properties. The results of this study show that the effect of bacteria on clay phyllites increases the calcium carbonate content, specific surface area and plasticity values. These increased values are caused by the addition of a non-plastic component to clay phyllites resulting in a more aggregated structure through the precipitation of calcium carbonate from the bacteria, ultimately filling the pores of this material. Microbiological treatments on clay phyllites tends to aggregate the original particles, creating aggregates that are partially associated with the formation of calcium carbonate. Said process is influenced by the curing and compaction procedures conducted on samples, which also cause breakage of carbonated structures formed during treatment. As a result of this breaking process of aggregates, some compaction energy is lost and the treated samples do not reach the maximum dry density of the natural state for the same level of compaction energy applied. Treated samples display a slightly larger friction angle with no cohesion, consistent with filling properties and denser condition. Compressibility is consistently lower than that of the natural state. Comparison of collapse data shows that the occurrence and amount of collapse are controlled by the as-compacted dry density. It is also determined that higher compaction effort is even more effective than increasing the amount of bacteria introduced to stabilize the sample for the filling of pores (size ranges 3–50¿µm) with calcium c, Peer Reviewed, Postprint (author's final draft)

This paper describes the use of industrial wastes arising from different production processes of the ceramic and marble industries as raw materials for the design and formulation of new cement clinkers with a high content of dicalcium silicate (Belite). The aim was to reintroduce these wastes in the industrial sector and take advantage of them for a greater environmental benefit, as indicated by the principles of the circular economy. Formulations containing 2.5, 5 and 10 wt% of chamotte and marble sludge, respectively, and a waste-free formulation have been designed to obtain clinkers with a content of dicalcium silicate higher than 60 wt%. The different blends have been studied up to a maximum temperature of 1390°C by Thermal Analysis. Other techniques such as XRD, XRF, Modified Bogue Equation, Quality Indexes (LSF, AM, SM) and Optical Microscopy have been used for the study and characterization of industrial wastes, the raw materials and the high belite-type cement dosages. The results indicate that this type of cements can be designed using different types of wastes and in this way reduce the environmental impacts caused by the extraction of raw materials and the deposition of the wastes in landfills, improving the circular economy of the construction industry.

The aim of this investigation was to determine the suitability of phyllite clays as a raw construction material. For that purpose, the cement in mortars was replaced by a phyllite clay (0–90 wt%) making this study the first of its kind to be performed. These materials were prepared with different water proportions according to the water content and water/cement and water/binder (cement plus phyllite clay) relationships. A comparative study of the most important properties of the resulting experimental mortars was carried out, such as apparent density, water retentivity, consistency and mechanical strength (flexural and compressive strength), along with an evaluation of the pozzolanic activity and permeability. The results showed that the increase of phyllite decreases the apparent density, the consistency and mechanical properties of the mortar, while water retentivity fluctuates. Good correlations (R2 > 0.84) were obtained between flexural and compressive strength for the mortars after 28 days of curing. Pozzolanic activity was observed at cement replacement of 80 wt% of phyllite. Moreover, new impermeabilizing mortars constituted by phyllite clay and cement have been obtained according to the low coefficients of permeability. Taking into account the findings of this research, phyllite clays can be applied as raw construction materials with savings derived from replacing cement in mortars and the low energy consumption involved in their production. However, the present study concluded that the use of phyllite clays did not improve the mechanical strength of these new mortars but, in contrast, they can be applied for impermeabilization purposes in Construction and Civil Engineering.

El objeto de la invención es una composición que contiene como principio activo ácido monocloroacético (MCA), en disolución con etanol (50% en volumen), preparado según un procedimiento que se describe, empleado para el tratamiento químico sistemático de la verruga plantar (papilomavirus humano plantar), sin cirugía, produciendo su cauterización química.

[EN] In this work, we studied the mechanical performance of an LDPE film (0.22 mm in thickness) used as a material in the design of greenhouse covers. We investigated the effects of ageing at different periods of its service life and applying chemical substance treatments used as pesticides on greenhouse crops and after breakage using mechanical traction. Numerical simulations were performed using the finite element method. For this purpose, one section of the complete geometry of the greenhouse cover and different load conditions (1-5 kPa) were considered for the modelling. The performance of the polymer was assumed to be linearly elastic to simplify the governing equations. The study demonstrated that the LDPE film used was no longer effective as a greenhouse cover film due to the degradation of its mechanical properties. It was shown that the general performance of this film was in the plastic zone and its performance was non-linear. The results deduced from the present study are of interest because they show the material failure process of greenhouse covers in relation to the degradation process., [ES] En este trabajo hemos estudiado el comportamiento mecánico de un film de LDPE (0.22 mm de espesor) usado como material para el diseño de cubiertas de invernaderos. Se ha investigado el efecto del envejecimiento en diferentes períodos de la vida útil, en los que se han aplicado tratamientos con sustancias químicas, utilizadas como pesticidas en cultivos de invernadero y después de la rotura mediante tracción mecánica. Las simulaciones numéricas se realizaron utilizando el método de elementos finitos. Para la modelización se ha considerado una sección de la geometría completa de la cubierta y diferentes condiciones de carga (1-5 kPa). Además, se asumió que el rendimiento del polímero era linealmente elástico para simplificar las ecuaciones. El estudio demostró que el film no estaba en condiciones de ser usado en la cubierta del invernadero debido a la pérdida de sus propiedades mecánicas. También se ha observado que el comportamiento general de la cubierta está en la zona plástica del material y, por tanto, tiene un comportamiento no lineal. Los resultados de las comparaciones realizadas son interesantes y de gran ayuda para ilustrar el proceso de falla del material de las cubiertas de invernadero en relación con el proceso de degradación.

Geopolymers are a new class of non-Portland cements produced using an alumino-silicate material and an activating solution, which is mainly composed of sodium or potassium and waterglass to be subsequently cured at relatively low temperatures. Those can be formulated by adding natural minerals, waste and/or industrial by-products. The study investigates the microstructural properties of geopolymers synthesized from metakaolin (MK) and the admixture of fly ash (FBA) and aluminium industry slags (AIS) at different ages of curing. Five different geopolymer compositions were prepared and characterized by XRD, ATR-FTIR and SEM/EDS. The study revealed that geopolymeric gels are identified, which show mainly glassy microstructures, in agreement with the X-ray amorphous diffraction patterns, broad FTIR features and confirmed by SEM/EDS, with promising results prior to an industrial scale.

Thermal analysis of some sericite clays, from several deposits in Spain, which are not exploited at this time, has been studied. The samples have been previously characterized by mineralogical and chemical analysis. Sericite clays have interesting properties, with implications in ceramics and advanced materials, in particular concerning the formation of mullite by heating. According to this investigation by differential thermal and thermogravimetric analysis (DTA-TG), the sericite clay samples can be classified as: Group (I), sericite–kaolinite clays, with high or medium sericite content, characterized by an endothermic DTA peak of dehydroxylation of kaolinite with mass loss, which overlapped with dehydroxylation of sericite, and Group (II), sericite–kaolinite–pyrophyllite clays, with broader endothermic DTA peaks, in which kaolinite is dehydroxylated first and later sericite and pyrophyllite with the main mass loss, appearing the peaks overlapped. X-ray diffraction analysis of the heated sericite clay samples evidenced the decomposition of dehydroxylated sericite and its disappearance at 1050 °C, with formation of mullite, the progressive disappearance of quartz and the formation of amorphous glassy phase. The vitrification temperature is ~ 1250 °C in all these samples, with slight variations in the temperatures of maximum apparent density (2.41–2.52 g mL−1) in the range 1200–1300 °C. The fine-grained sericite content and the presence of some mineralogical components contribute to the formation of mullite and the increase in the glassy phase by heating. Mullite is the only crystalline phase detected at 1400 °C with good crystallinity. SEM revealed the dense network of rod-shaped and elongated needle-like mullite crystals in the thermally treated samples. These characteristics are advantageous when sericite clays are applied as ceramic raw materials.

Fly ash is a biomass combustion by-product produced by dragging ash from the base of the furnace. Disposing of ash is a growing economic and environmental burden. Based on physical and chemical properties, fly ash could be used in the manufacture of construction materials. This paper investigates the influence of biomass fly ash from olive pomace as additive to manufacture of clay ceramic composite materials. Fired clay brick at 950 °C were prepared containing between 0 and 25 wt% fly ash. Final products are studied by water absorption, bulk density, loss of ignition, linear shrinkage, compressive strength and physisorption N2. The results reveal that the porosity of the materials increases with the level of fly ash replacement (10% up to 25 wt%) resulting in to increased water absorption and decreased compressive strength. Fired clay brick developed in this study can be used for construction materials based on criteria of the current regulations.

The most representative of greenhouse-crop plant biomass residues of tomatoes (Solanum lycopersicum L.) were selected for this study by using X-ray fluorescence spectrometry (XRF) and X-ray powder diffraction (XRD). The heating dynamics in air in the 600–1150 °C range of these residues for the production of renewable energy and the resultant ashes have been investigated. A total of 11 elements were determined by XRF in the biomass ashes and some minor elements. The content of alkaline elements and chlorides decreased as increasing heating temperature and disappeared at 1150 °C. Alkaline salts, NaCl and KCl, were volatilized by heating since 800 °C. The total contents of S and P in the biomass ashes were associated to CaSO, and a complex phosphate identified by XRD. CaCO present at 600 °C was decomposed to CaO with disappearance at 1000 °C. By heating, new silicates were formed by solid-state reactions in the biomass residue. The minor elements have been found in a relative proportion lower than 0.9 wt.% and they characterized the obtained ashes, with potential use as micronutrients.

The use of coal fly ash (CFA) as raw material for the manufacture of two construction materials, fired clay bricks and silica-calcareous non-fired bricks, was investigated. Fired clay bricks were manufactured using a commercial clay and different waste ratios (0–50 wt%), moulded at 10 MPa and fired at 1000 ºC (4 h). Silica-calcareous non-fired bricks were prepared using two wastes as raw material: CFA and “geosilex”(G), a hidrated lime residue which comes entirely from acetylene industry waste. Different proportions CFA (80–30 wt%) – G (20–70 wt%) were investigated. Raw materials were moulded at 10 MPa and cured in water at room temperature during 28 days. The results indicated that the incorporation of up to 20 wt% of CFA produced fired clay bricks with physical and mechanical properties similar to control bricks without waste. However, additions of a higher amount (30–50 wt%) of residue resulted in a more pronounced decrease in mechanical properties (between 25–50%) due to an increase in open porosity. The technological characterization of the silica-calcareous non-fired bricks showed a reduction in the values of bulk density and water absorption when the coal fly ash content decreases. Silica-calcareous non-fired bricks containing between 40 and 60 wt% of CFA had the highest values of compressive strength in the range 46–43 MPa. These silica-calcareous non-fired bricks, 60CFA-40 G, 50CFA-50 G and 40CFA-60 G, presented the optimum amount of pozzolanic materials (SiO and AlO) in the coal fly ash and calcium hydroxide in the geosilex to give rise to the formation of calcium silicate hydrates and calcium aluminate hydrates, the phases responsible for the mechanical resistance increase of the construction materials. Therefore, CFA-clay fired bricks and silica-calcareous CFA-Geosilex non-fired bricks presented optimal technological properties that attain the quality standards.

It is reported the synthesis of CaCO3 vaterite as stable nanoparticles and submicron-sized by a simple and relatively rapid procedure. XRD, SEM and FTIR techniques have been used to characterize the precipitated products. The synthesis is based on chemical precipitation of inorganic salt precursors, calcium nitrate tetrahydrate and sodium bicarbonate, and using the disaccharide sucrose as an additive in aqueous medium. The role of the disaccharide sucrose is to control the vaterite precipitation after nucleation and growth. It has been found that an increase in sugar concentration promotes the crystal precipitation of vaterite with spherulitic morphology, as revealed by SEM, and changed the surface of the precipitated particles. There is a significant difference between CaCO3 precipitation in the absence and presence of sucrose. Addition of 0% of sucrose leads to 83% of calcite as identified by XRD methods. In contrast, addition of 67% of sucrose in aqueous medium produces 100% vaterite. The present results may be useful to provide a quick, simple, inexpensive and novel method for the controlled synthesis of new advanced biomaterials based on vaterite particles without hazardous chemicals and inert atmosphere, with great possibilities for industrial scale production

El objeto de esta Tesis Doctoral es el estudio de la producción y comercialización de los excedentes agropecuarios procedentes del entorno del Bajo Guadalquivir, con especial hincapié en el análisis de las redes de distribución de las mercancías a través de los recipientes que los contenían, las ánforas Pellicer BC y Pellicer D. El marco cronológico del estudio se sitúa, dentro de la Protohistoria, en la II Edad del Hierro, es decir, desde el tránsito al siglo V a.C. (inicio de la II Edad del Hierro) hasta finales del siglo I a.C. La investigación se ha desarrollado a través del análisis, desde distintas perspectivas, de los recipientes cerámicos anfóricos, principales contenedores mediante los cuales los excedentes agrícolas fueron transportados y redistribuidos. Las riberas del Guadalquivir y la campiña de Sevilla constituyen un ámbito geográfico especialmente interesante para la aplicación de un estudio de este tipo, dado el desarrollo que experimenta la zona en este periodo histórico mediante las relaciones externas que influencian, a escala local y regional, a las sociedades prerromanas turdetanas. En este trabajo se ofrece una definición tipológica, composicional y tecnológica de la variabilidad productiva de los recipientes anfóricos del Bajo Guadalquivir. En base a dichas caracterizaciones, se establecen asociaciones entre ciertas particularidades morfológicas o arqueométricas y talleres alfareros concretos, lo que permite profundizar en el papel que desempeñaron los principales asentamientos de la zona en la red comercial de distribución y consumo de excedentes alimentarios. En el marco de este registro material, hemos afrontado distintos problemas productivos, desde la implantación y la actividad de los talleres responsables de estas manufacturas hasta las elecciones tecnológicas de sus artesanos, pero también comerciales y organizativos, como la circulación de estos envases, sus contenidos, su registro o su identificación por parte de los consumidores., This Doctoral Thesis studies the production and commercialisation of the rural surplus of the lower Guadalquivir Valley, focusing on the analysis of the distribution networks of the commodities through the consideration of their containers, the Pellicer BC and Pellicer D amphora types. Chronologically, this production concentrates on the Late Iron Age, the end of the Protohistory, more concretely from the beginning of the 5th century BC to the end of the 1st century BC. The research of the transport and distribution of the agricultural surplus has been conducted through the multi-perspective analysis of the amphorae. The riverbanks of the lower Guadalquivir and the countryside of Seville are an ideal geographical area for developing such a study, considering the evolution of the region during this historical period due to the external connections that influenced the Pre-Roman Turdetanians at a local and regional scale. This Dissertation offers a typological, compositional and technological definition of the variability in the production of amphorae in the lower Guadalquivir Valley. On the basis of these characterisations, several associations between morphological or archaeometrical features and specific pottery workshops have been established. Consequently, these relations lead to a better understanding of the economic roles of the main settlements of the region in the alimentary surplus distribution and consumption network. The study of the ceramic assemblages have considered productive questions, from the establishment and the activity of the workshops to the technological choices of the potters, but also commercial and organization problems, as the movement of the amphorae, their content, their registration system or the identification of the product by the recipients.

The principal aim of this work is to examine the effect of thermal treatments using a muffle furnace (static heating) and by simultaneous TG/DTA (dynamic heating) on selected greenhouse crops plant biomass investigated here as the first time. The effect of fractionation by sieving (<25 and <2.5 mm), preheating at 150 °C for 48 h and leaching with water on the thermal behavior has been studied. The observation of similar profiles of mass variation corresponding to several samples heated in air up to 1150 °C allows to conclude that particle size did not influence the thermal evolution, but the effect of heating cycle is evidenced. Thermal analysis in air of a representative sample showed the several mass variation steps and DTA exothermic effects produced by the complex thermal decomposition and pyrolysis of the organic matter. Elemental analysis (CHNS and O) of the starting samples and thermally treated revealed the effect of the temperature, with formation of ashes with lower C content from 44.37 to 0.70 mass% as a minimum after elimination of organic matter by heating. Leaching increased the thermal mass variation as an effect of elimination of water-soluble components. According to the present results, the size fractionation of the greenhouse crops biomass did not influence the results of elemental composition. The present study has provided results of interest concerning this biomass source of renewable energy originated by the remains of tomato (Solanum lycopersicum L.), being estimated the highest of all the biomass produced by the greenhouse crops agricultural industry in Almería (SE Spain).

El objeto de la invención es una composición que contiene como principio activo ácido monocloroacético (MCA), en disolución con etanol (50% en volumen), preparado según un procedimiento que se describe, empleado para el tratamiento químico sistemático de la verruga plantar (papilomavirus humano plantar), sin cirugía, produciendo su cauterización química.

[EN] It is presented a procedure to determine the aging of greenhouse cover materials constituted by a polymer material. For this purpose, it is performed a continued monitoring of the photosynthetically active radiation (PAR) and the global radiation during three campaigns. It has been studied in this research samples taken at different zones of the cover, after breakage using mechanical traction. It is deduced a useful life of the polymer of two years, being the average transmitted PAR of 37.44%. However, the absorbed global radiation is determined a value of 36.29%. Furthermore, the elongation to the breakage is above of 500%. This high value is associated to an intense degradation of the polymer material. At the same time, the zone where the sample was taken seems to influence both the strength of mechanical traction and the elongation at the fluence point. The designed tests have been useful to develop a modellization procedure based on the minimum squared method for the adjustment of the data. The proposed model can be used for the design of greenhouse covers and thus allows predict the degree of deterioration of the polymer material at every moment. It is also interesting to keep watch of the need of removing it. The numerical simulations using the finite elements method can represent adequately the mechanical behavior of the cover material. It is been also deduced in this research that the behavior of the covers is at the plastic zone of material., [ES] Se presenta un procedimiento para la determinación del envejecimiento de un material polimérico utilizado como cubierta de invernaderos. Se llevó a cabo un seguimiento continuo de la radiación fotosintéticamente activa (PAR) y de la radiación global durante tres campañas. Igualmente, se tomaron muestras de diferentes zonas de la cubierta, que se han roto a tracción. Se deduce una vida útil del material polimérico de dos años, siendo radiación PAR media trasmitida del 37,44%. Sin embargo, la radiación global absorbida fue de 36,29%. Igualmente, se ha verificado que la elongación a la rotura está por encima del 500%. Este alto valor se debe a que el polímero está muy degradado. También se observó que la zona donde se ha tomado la muestra influye tanto en la resistencia a tracción como en la elongación en el punto de fluencia. Los ensayos han sido de utilidad para desarrollar un procedimiento de modelización basado en el método de mínimos cuadrados para el ajuste de los datos. El modelo propuesto presenta utilidad para el diseño de cubiertas para invernaderos y permite así predecir el grado de deterioro del material polimérico en un instante determinado, alertando también de la necesidad de renovación del mismo. De este modo, las simulaciones numéricas con elementos finitos pueden representar de forma adecuada el comportamiento mecánico de las cubiertas. Se comprobó que el comportamiento de la cubierta está en la zona plástica del material