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In this article, the results of a treatment applied to dolomitic stones using an isopropyl colloidal solution based on calcium hydroxide nanoparticles with a concentration of 2.0g/l are presented. The consolidation process in the stone has been checked before and after 28 days of exposure to 75% relative humidity. Morphologic and structural studies of the consolidating product confirmed the carbonation process. X ray diffraction, electron microscopy (TEM and ESEM), and electron diffraction carried out on the consolidating product have confirmed the transformation of portlandite phase to calcium carbonate polymorphs, calcite, aragonite and vaterite. Petrophysical tests performed on the stone before and after the application of the product have shown the improvement in the physical and hydrical properties due to the increase in the ultrasound velocity and density of the material, and a decrease in the capillarity coefficient and open porosity without significant changes in colour and brightness. The application of the consolidating product in the proposed experimental conditions is a natural method, compatible with the petrological characteristics of the substrate, without secondary damages on the stone, being an effective method to improve the durability of carbonate stones.En este artículo se presentan los resultados del tratamiento aplicado a muestras de piedra dolomía mediante una solución coloidal isopropílica basada en nanopartículas de hidróxido de calcio en una concentración de 2,0g/l. El proceso de consolidación de la piedra ha sido monitoreado antes y después de su aplicación a los 28 días de estar expuesta a una atmósfera del 75% de humedad relativa. Se ha realizado un estudio morfológico y estructural del consolidante confirmándose el proceso de carbonatación. Los resultados de difracción de rayos X, microscopía electrónica (TEM y ESEM) y difracción de electrones realizados al producto consolidante han confirmado la transformación de la fase portlandita a los polimorfos de carbonato de calcio de tipo calcita, aragonito y vaterita. Los ensayos petrofísicos realizados a la piedra antes y después de su aplicación, han demostrado que se produce una mejora de las propiedades físicas e hídricas indicado por el aumento tanto en la velocidad de propagación de ultrasonidos como en la densidad del material y una disminución de su coeficiente capilar, así como de la porosidad abierta sin producirse modificaciones significativas en el color y el brillo. La aplicación del tratamiento de consolidación propuesto, con este tipo de soluciones coloidales de nanopartículas, es un método natural y compatible con las características petrológicas del sustrato, sin generar daños secundarios sobre la piedra, resultando un método eficaz para la mejora de la durabilidad de rocas carbonáticas.

A new designed stainless steel door, which holds cooling fluids, permits connect a set of sensors (DTA, RH, RL) to a traditional diffractometer and record sets of isothermal and non-isothermal diffraction profiles (in a range of 17ºC-200ºC) allowing dehydration and retrenchment effects of an historical claystone from Toledo to be studied. In addition, a little oven into an environmental scanning electron microscope (ESEM) has been used to dry the claystone sample being analyzed with EDS up to 400ºC. In both equipments (XRD & ESEM) chambers, temperature and relative humidity are controlled. The crystallographic (00l) planes of illite are twisted during the water leaking. The dehydration (circa 80ºC) and dehydroxilation (circa 380ºC) processes of the illite are observed. At high temperature (900ºC) electron microscopy photographs of calcium oxide, stemming from calcite, were saved.Se aplica una nueva puerta termo-refrigerada de construcción propia, con varios tipos de sensores acoplados (Análisis Térmico Diferencial, Humedad Relativa, Radioluminiscencia), a un difractómetro clásico para registrar perfiles de difracción secuenciales isotermales y noisotermales (en el rango de 17ºC-200ºC). Con este dispositivo se estudiarán procesos de deshidratación y contracción de una arcilla histórica de Toledo. Además, se ha utilizado un microscopio electrónico ambiental (ESEM) con una cámara térmica interna (de 17ºC a 1000ºC) para secar la arcilla y analizarla con el EDS hasta 400ºC. En ambos equipos se controló la temperatura y la humedad relativa dentro de las cámaras de análisis. Los movimientos de contracción de secado han reorientado planos (00l) de la illita, la muestra ha deshidratado hacia los 80ºC y ha deshidroxilado hacia los 280ºC. A elevadas temperaturas in situ (900ºC), se tomaron fotografías de óptica electrónica del óxido de calcio procedente de la descomposición de la calcita.

Zircon (ZrSiO4) is a mineral widely employed in the production of refractories, pigments, glazed tiles etc. The high radioactive content of this mineral stems from the presence of natural alpha emitters as U and Th. The radioactive activity of the 238U, 235U and 234U, 228Th, 230Th and 232Th radionuclides was measured by alpha spectrometry after isolation by radiochemical techniques. The alpha-emitters uranium and thorium irradiates internally the ceramic modifying the luminescence properties, this involves a potential use for dosimetric purposes. The thermoluminescence (TL) glow curve intensity of zircon is higher than the observed in other aluminosilicates measured under the same conditions. The TL maxima appearing at 280, 360 and 445oC are fairly well correlated with the differential thermal analysis (DTA). It suggests that this TL peaks could be linked to: (1) partial processes of local phase transitions and (2) alkali self-diffusion dehydroxylation phenomena when the sample is heated during the analytical measurement routine.El circón (ZrSiO4) es un material que se utiliza habitualmente en la fabricación de refractarios, esmaltes para azulejos, pigmentos, etc. Este mineral tiene un alto contenido radiactivo debido a la presencia de emisores alfa naturales como U y Th. En este trabajo se ha determinado el contenido isotópico de estos radionucleidos (238U, 235U y 234U, 228Th, 230Th y 232Th) utilizando técnicas de separación radioquímicas y cuantificando la actividad mediante espectrometría alfa. Estos radioisótopos naturales producen una irradiación interna en el material cerámico que se manifiesta en sus propiedades luminiscentes lo que implica que pueda ser utilizado con fines dosimétricos. Se ha observado que la curva de termoluminiscencia (TL) del circón muestra una intensidad considerablemente mayor (más de un orden de magnitud) que la de otros silicatos medidos en idénticas condiciones. Los máximos que aparecen en la curva de TL se correlacionan con distintos puntos de inflexión que aparecen en la medida de análisis térmico diferencial (ATD), a 280, 360 y 445oC, lo que indica que estos picos de TL aparecerán como consecuencia de: (1) procesos parciales de transiciones de fase locales y (2) fenómenos de autodifusión iónica y deshidroxilación que se producen durante el calentamiento al realizar la medida.

La pancreatitis post-CPRE (PPC) es la complicación más frecuente de la colangiopancreatografía endoscópica (CPRE), la cual ocurre en el 8 al 15% de los casos; el diagnóstico se establece con la presencia de dolor dentro de las siguientes 24 horas posterior al procedimiento acompañado de elevación de las enzimas pancreáticas (> 3 veces el valor normal). Se han identificado factores de riesgo del paciente (sexo femenino, edad < 60 años, episodios previos de PPC, sospecha de disfunción de esfínter de Oddi) y factores de riesgo asociados al procedimiento (canulación difícil, manometría del esfínter de Oddi, ampulectomía, opacificación y/o canulación del conducto pancreático, mayor número de intentos de canulación de la papila de Vater, esfinteroplastia hidroneumática). También se han investigado varias medidas profilácticas; sin embargo, las que han mostrado eficacia en la profilaxis para PPC se dividen en farmacológicas (antiinflamatorios no esteroideos por vía rectal) y no farmacológicas (precorte temprano, prótesis pancreática, hidratación endovenosa agresiva). Es importante identificar los factores de riesgo y llevar a cabo las medidas profilácticas necesarias para disminuir la incidencia de PPC.

En el presente escrito se analiza, a la luz de la teoría sobre capital social, la movilización y protesta ciudadana que se realizó a finales de 2007 en Guadalajara, para detener el intento del gobierno estatal por realizar un reemplacamiento del parque vehicular del estado de Jalisco. Se concluye que el éxito de la movilización ciudadana generó incentivos y coadyuvó en la construcción de capital social, ayudando, además, a reforzar la confianza ciudadana en la protesta y movilización como instrumentos legítimos de lucha de la sociedad.

The kinetic parameterisation of lime mortar carbonation is a useful technique for understanding ancient building methods and the long-lived physical-chemical stability of roman monuments. Portlandite (Ca(OH)2) binders harden in the air on contact with atmospheric CO2, producing CaCO3. Water evaporation and the presence of silicate aggregates have a three-fold effect: prompting the development of a pore system that permits CO2, self-diffusion, reducing shrinkage and cracking during drying and (possibly) giving rise to subsequent pozzolanic reactions. The present survey involved air-hardening a series of roman-like lime mortars which differed in terms of: (i) type of aggregate, volcanic tephra and arkose; (ii) aggregate/binder ratio, 1:2 as used in the catacombs and 1:4 as found in standard roman construction and (iii) temperature, the 17 ºC prevailing in underground environments and the 30 ºC typical of warm Mediterranean areas. The analyses that provided the most useful information were performed in a classic X-ray diffractometer adapted to accommodate an author-designed chamber in which temperature control was achieved by an internal refrigerant and a PID-governed electrical heater Additional data were obtained with DTA and environmental scanning electron microscopy (ESEM). The tests conducted on the Roman-like lime mortars manufactured for the experiment showed that the hardening temperature is a critical factor in the initial phases of carbonation. Calcite precipitation rates and total mineral precipitation increased with temperature, but fell very quickly as calcite precipitated. In theoretical calculations assuming an open reactor with continuous CO2, input, total calcitisation time was found to be 156 m in. at 30 ºC and 175 min. at 17 ºC, whilst in the mortars actually hardened in the experimental part of the study, calcitisation gradually blocked the flow or CO2, gas into the system. Roman-like mortars air-hardened at 30 ºC displayed higher initial calcitisation rates, early system closure and low final carbonation levels. The calcitisation rates of mortars made with pozzolana aggregates were higher than the arkose mortar rates due to the higher intra-particle porosity (nearly 40%) of the volcanic rock fragments.

Bacterascites (BA) is a minimally studied and defined entity. Its prognosis and clinical course are not well defined, and currently there are no management guidelines. We present a rare cause of BA in which Salmonella sp group A was isolated in a 44 year old man with cirrhosis who had diarrhea and fever three days earlier. Treatment with intravenous ceftriaxone was effective.

The consolidation effects of portlandite nanoparticles have been determined in carbonate stones (dolostone), typically used in historical buildings from Madrid, Spain, just after 20 days consolidation at 20°C under a dry [33% relative humidity (RH)] and a humid environment (75% RH) and after 18 months under room temperature and humidity conditions ( and RH). The improvement of the physical and hydric properties, from short to longer term, of this dolostone is shown through the combination of nondestructive techniques (environmental scanning electron microscopy, spectrophotometry, water absorption under vacuum and capillarity, ultrasonic velocity, and optical surface roughness analyses) together with destructive techniques (mercury intrusion porosimetry and microdriling resistance measurement) also necessary for a better accuracy determination of pore structure and resistance modifications. Consolidation process under both humid and dry environment gives rise to an improvement of the petrophysical properties of dolostone specimens. However, a humid environment and a higher and larger porosity of the stone favor the consolidation with time, being these conditions are necessary to take into account when nanoparticles are used to consolidate carbonate stones. [ABSTRACT FROM AUTHOR]

A study of the stability of calcium carbonate polymorphs formed as a result of the carbonation process from an alcoholic colloidal solution of nanocrystals of Ca(OH) in low relative humidity (RH) conditions (33% and 54% RH) is presented in this research. The crystalline behavior, the time dependence of nucleation and the phases' transformations as a result of exposure to low humidity conditions are evaluated. The carbonation process is slow, starting with the nucleation of amorphous calcium carbonate, associated to an amorphization process that affects both the portlandite (Ca(OH)) and the initial unstable CaCO polymorphs. The excess of alcohol in the solution decreases the surface tension and the nucleation is accelerated by the fast evaporation of the solvent, which avoids the particles to diffuse to their lowest energy sites, giving smaller particles with lower crystallinity as RH decreases. [ABSTRACT FROM AUTHOR]

Romans, Jews, Arabs and Christians built the ancient city of Toledo (Spain) with bricks as the main construction material. Manganese micro-nodules (circa 2 μm in diameter) have grown under the external bio-film surface of the bricks. Recent anthropogenic activities such as industrial emissions, foundries, or traffic and housing pollution have further altered these old bricks. The energy-dispersive X-ray microanalyses (XPS) of micro-nodules show Al, Si, Ca, K, Fe and Mn, with some carbon species. Manganese atoms are present only as Mn4+ and iron as Fe3+ (FeOOH–Fe2O3 mixtures). The large concentration of alga biomass of the River Tagus and the Torco´n and Guajaraz reservoirs suggest manganese micro-nodules are formed either from water solutions rich in anthropogenic MnO4K in a reduction environment (from Mn7+ to Mn4+) or by oxidation mechanisms from dissolved Mn2+ (from Mn2+ to Mn4+) linked to algae biofilm onto the ancient brick surfaces. Ancient wall surfaces were also studied by scanning electron microscopy (SEM-EDS) and X-ray diffraction (XRD). Chemical and biological analyses of the waters around Toledo are also analysed for possible sources of manganese. Manganese micro-nodules on ancient brick walls are good indicators of manganese pollution. [Copyright &y& Elsevier]

Albite sodium feldspar is studied by thermoluminescent methods using the blue region of the spectra (circa 400nm) and the possible uses as a dosimeter are explored. The light emission of the spectra bands of natural and irradiated albite under X and gamma rays are determined using automated RISØ thermoluminescence equipment. Albite is a potential material to be used as retrospective dosimeter due to its good blue thermoluminescence characteristics in good agreement with the dosimetric requirements. It is sensitive to radiation, possesses a good linearity (0.06-8Gy), shows an acceptable stability in time, it is highly reproducible and can detect low levels of dose (60mGy). The TL glow curves emission exhibit a very complex structure associated to a continuous trap distribution. This behaviour could be explained as a consequence of a dynamic creation-annihilation of a [AlO4/alkali]+ and [AlO4]o centres.Se estudian las posibilidades dosimétricas de la albita (feldespato sódico) por métodos termoluminiscentes utilizando la región espectral del azul (alrededor de los 400nm). Se registran las posiciones espectrales de emisión de luz de este material irradiado con rayos X y con radiación gamma en un equipo automático de termoluminiscencia Risø. La albita puede ser empleada potencialmente en el campo de la reconstrucción de dosis post-accidental ya que sus propiedades termoluminiscentes en la región espectral del azul presentan buenas características dosimétricas. Se observa que la albita es muy sensible a la radiación, presenta una excelente linealidad con la dosis (0.06-8Gy), muestra una gran estabilidad con el tiempo, tiene reproducibilidad aceptable y puede detectar bajos rangos de dosis (60mGy). Sus curvas de termoluminiscencia tienen una estructura compleja asociada a una distribución continua de trampas en todo el rango de temperaturas. Este comportamiento podría explicarse como consecuencia de la formación-aniquilación dinámica de centros [AlO4/alcali]+ y [AlO4]o.