Influence of Surface Finishes and a Calcium Phosphate-Based Consolidant on the Decay of Sedimentary Building Stones Due to Acid Attack

Natural stone has long been used as a building material because of its physical-mechanical resistance and its esthetic appeal. However, over the last century increasing industrial activity has produced more acidic environments, such as polluted urban areas, that can cause serious damage to many buildings and historic monuments, and in particular those made with carbonate rocks, which are most prone to decay. In order to mitigate the physicochemical processes that degrade these buildings, a number of phosphate-based consolidants have been developed, which are highly compatible with the carbonated substrate. Research about the role of the surface and its different possible finishes in the transmission of the agents that damage or protect the stone would therefore be very useful, both when choosing the most suitable stone for new constructions and when restoring historic buildings. The main objective of this research was to determine whether the roughness of three types of surface finish (saw-cut, honed and bush-hammered) influences the durability of four types of natural stone (two calcarenites, one travertine and one sandstone) widely used in Andalusia (Spain). The efficacy of a calcium phosphate-based consolidant as a mitigator of deterioration in polluted urban environments was also studied and to this end the physical properties of untreated and treated samples were measured and compared. The samples were exposed to artificial atmospheres with SO2 pollution in order to assess the damage caused to each surface finish. The results indicate that all the surface finishes were vulnerable to the decay caused by acidic atmospheres, although the saw-cut finish was less affected, perhaps because it did not require additional industrial processing. The mineral composition and texture of the rocks were critical factors in terms of the amount and type of decay they suffered, and the travertine and sandstone were more resistant to deterioration than the calcarenites. Similarly, the pore system of each rock was decisive in the penetration of the consolidant. Application of the consolidant improved the behavior of the treated samples by making them more resistant to acid attack without significantly altering the water vapor permeability, the color or the roughness of the surface

Outcomes of a Multi-Component Family Enrichment Project: 12-Month Follow-up

Previous research has established that family enrichment programs work with a variety of populations (e.g., Hawkins, Stanley, Blanchard, & Albright, 2012). It is unclear if a multi-component program focusing on a variety of family outcomes can lead to lasting change. This study used growth modeling to examine effects of relationship (i.e., Within My Reach), parenting (i.e., Making Parenting a Pleasure), and financial enrichment (i.e., Spend Some, Save Some, Share Some) classes over 12 months. Results revealed improvement in family functioning at one year post for all three programs. Program specific improvements included relationship functioning and parenting alliance. Program participants reported overall satisfaction and gaining of valuable skills. Findings suggest these family enrichment programs can have long-lasting effects; potential reasons for sample success and implications are discussed

Petrograhic features and physical properties of certain travertine building stones

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEMinisterio de Educación y Ciencia (MEC)pu

Sodium sulfate crystallisation monitoring using IR Thermography

In this work, the evaporation of sodium sulfate droplets with different concentrations and at different temperatures were studied using infrared thermography (IRT). IRT allows to detect the evaporation evolution, the crystal growth and for the first time, to observe in vivo the heat release related to sodium sulfate crystallisation. A detailed study revealed that dendritic Thenardite III crystals appeared at the edge of all the crystallised droplets, though they showed a fast increase of temperature related to crystallisation only when a hydrated phase crystallised also from the droplet. The observation of the heat of crystallisation is thus directly related to the supersaturation of the droplet and consequently to temperature. In addition, IRT detection is circumscribed by the location of crystallisation. The heat can be observed and measured only when the crystallisation occurs in the interface solution – air

Approximately dual pairs of wavelet frames

This paper deals with structural issues concerning wavelet frames and their dual frames. It is known that there exist wavelet frames $\{a^{j/2}\psi( a^j\cdot -kb)\}_{j,k\in \mathbb Z}$ in $L^2(\mathbb R)$ for which no dual frame has wavelet structure. We first generalize this result by proving that there exist wavelet frames for which no approximately dual frame has wavelet structure. Motivated by this we show that by imposing a very mild decay condition on the Fourier transform of the generator $\psi\in L^2(\mathbb R),$ a certain oversampling $\{a^{j/2}\psi( a^j\cdot -kb/N)\}_{j,k\in \mathbb Z}$ indeed has an approximately dual wavelet frame; most importantly, by choosing the parameter $N\in \mathbb N$ sufficiently large we can get as close to perfect reconstruction as desired, which makes the approximate dual frame pairs perform equally well as the classical dual frame pairs in applications

Diseño y montaje de una planta piloto para la extracción de quitina y proteínas

El proyecto se basó en el diseño y montaje de una planta piloto para la extracción química de Quitina y proteínas a partir de desechos de crustáceos (camarón y langostino). Se determinó el contenido de humedad del material y las condiciones experimentales óptimas de volumen y concentración de los reactivos involucrados en el proceso. Además, se realizó un análisis técnico y económico del mismo. Los resultados mostraron que la materia prima tiene un alto contenido de humedad entre 68-80% y que las condiciones experimentales para la obtención de Quitina dependen fuertemente de las características del material. Bajo estas condiciones se obtuvo una recuperación mayor del 98% para el caso de caparazón de camarón y de aproximadamente un 58% en el caso del langostino. Por otro lado, para la extracción de proteínas se encontró que la mayor producción ocurre a pH 4.0 y con soluciones provenientes del proceso de desproteinización, sin trituración previa de la materia prima. El estudio técnico proporcionó información básica sobre los costos e inversión del proceso operativo, datos sobre las instalaciones y los equipos asociados al proceso productivo. El análisis económico mostró que se debe tener una inversión inicial de US $10,520.94 para el montaje de la planta piloto y de US$ 4,852.58 para gastos de transporte y operación por seis meses. Palabras claves: caparazón de camarón; langostino; método químico; planta piloto; proteínas, quitina. DOI: http://dx.doi.org/10.5377/nexo.v22i2.42 Nexo: Revista Científica Vol. 22, No. 02, pp.45-55/Diciembre 200

Ultrasonographic Estimation of Ventricular Volume in Infants Born Preterm with Posthemorrhagic Ventricular Dilatation: A Nested Substudy of the Randomized Controlled Early Versus Late Ventricular Intervention Study (ELVIS) Trial

Objective: To study the potential role of ventricular volume (VV) estimation in the management of posthemorrhagic ventricular dilatation related to the need for ventriculoperitoneal (VP)-shunt insertion and 2-year neurodevelopmental outcome in infants born preterm. Study design: We included 59 patients from the Early vs Late Ventricular Intervention Study from 4 participating centers. VV was manually segmented in 209 3-dimensional ultrasound scans and estimated from 2-dimensional ultrasound linear measurements in a total of 1226 ultrasounds. We studied the association of both linear measurements and VV to the need for VP shunt and 2-year neurodevelopmental outcome in the overall cohort and in the 29 infants who needed insertion of a reservoir. We used general estimating equations to account for repeated measures per individual. Results: Maximum pre-reservoir VV (β coefficient = 0.185, P = .0001) and gestational age at birth (β = −0.338; P = .0001) were related to the need for VP shunt. The estimated optimal single VV measurement cut point of 17 cm3 correctly classified 79.31% with an area under the curve of 0.76 (CI 95% 0.74-0.79). Maximum VV (β = 0.027; P = .012) together with VP shunt insertion (β = 3.773; P = .007) and gestational age (β = −0.273; P = .0001) were related to cognitive outcome at 2 years. Maximum ventricular index and anterior horn width before reservoir insertion were independently associated with the need of VP shunt and the proposed threshold groups in the Early vs Late Ventricular Intervention Study trial were associated with long-term outcome. Conclusions: Pre-reservoir VV measurements were associated with the need for VP-shunt insertion and 2-year cognitive outcome among infants born preterm with posthemorrhagic ventricular dilatation. Trial registration: ISRCTN43171322

Mechanical properties and coefficient of thermal expansion of β-eucryptite sintered by microwave technique

[ES]: La técnica de sinterización no convencional de microondas permite obtener materiales de ß-eucriptita en estado sólido cristalino con densidades cercanas a la teórica (~99 %). Se ha observado una diferencia considerable en estos materiales respecto a la técnica convencional en términos de densificación, microestructura, coeficiente de expansión térmica y propiedades mecánicas. Los valores de dureza y módulo de Young obtenidos mediante sinterización por microondas a 1200 ºC-5 min han sido relativamente altos, 6.8 GPa y 101 GPa, respectivamente, en comparación con el material obtenido mediante horno convencional (3.9 GPa y 58 GPa, respectivamente). Los datos dilatométricos obtenidos, incluyendo el intervalo de temperatura criogénica (-150 ºC a +150 ºC), muestran un coeficiente de expansión térmica controlado y negativo en todo el rango de temperaturas. La combinación de un calentamiento rápido junto con la reducción drástica en el tiempo de ciclo y el ahorro energético, hace que la técnica de microondas sean una clara alternativa a otro tipo de calentamientos.[EN]: Microwave non-conventional sintering technique allows obtaining fully dense glass-free β-eucryptite bulk material (∼99 %). A considerable difference in the densification, microstructure, coefficient of thermal expansion behaviour and mechanical properties, between conventional and non-conventional sintered specimens was observed. The hardness and Young’s modulus values obtained by microwaves at 1200 °C-5min have been relatively high, 6.8 GPa and 101 GPa, respectively, compared to conventional sintering (3.9 GPa and 58 GPa, respectively). Very low thermal expansion materials have been obtained in a wide temperature range including cryogenic temperatures (from -150 ºC to 150 ºC). The high heating rate along with the lower energy consumption makes microwave technique a clear alternative to other types of sintering methods.Los autores desean agradecer el apoyo financiero recibido de la UPV dentro de los proyectos SP20120621 y SP20120677 y, al gobierno español a través del proyecto (TEC2012-37532-C02-01). A. Borrell, agradece al Ministerio de Ciencia e Innovación su contrato de Juan la Cierva (JCI-2011-10498).Peer Reviewe

Life cycle analysis of hydrothermal carbonization of olive mill waste: Comparison with current management approaches

Significant efforts have been direct towards developing environmentally sustainable and economically beneficial treatment of olive mill wastes. Recently, hydrothermal carbonization (HTC) has been shown to be a potentially beneficial approach for the treatment of olive mill wastes. When considering the use of HTC to treat these wastes, however, it is critical that its environmental implications be evaluated and subsequently compared to other commonly used treatment approaches. In this study, the environmental impacts associated with using HTC to treat olive mill wastes were evaluated and compared to aerobic composting, anaerobic digestion, and incineration using life cycle assessment. Results indicate that HTC coupled with subsequent energy recovery from the combustion of the generated hydrochar results in net environmental benefits and that the energy offsets derived from electricity production from hydrochar combustion are critical to achieving these savings. In addition, results indicate that HTC process water discharge significantly influences system environmental impacts, indicating that research investigating treatment alternatives is needed. Changes in carbonization temperature and hydrochar moisture content also influence system environmental impact, suggesting that both are important when considering possible industrial applications. In comparison with current management approaches, alternatives using HTC are more environmental advantageous than composting and anaerobic digestion. However, the use of HTC is not as environmentally advantageous as incineration with energy recovery because 45-35% of the energy contained in the olive mill waste is lost during HTC. However, if the electricity recovery efficiency from incineration increases to greater than 30%, the environmental impacts associated with HTC and subsequent energy generation are equal to or better than direct TPOWM incineration with energy recovery. It is recommended that future research efforts focus on the evaluation of appropriate and environmentally beneficial HTC process water treatment approaches and methods to improve the energetic retention efficiencies of the hydrochar.Author V. Benavente kindly wishes to thank the Conselleria d’Educació, Cultura i Esport, for a Ph.D. grant (contract grant number ACIF/2014/275) and a pre-doctoral employee stays grant (grant number BEFPI/2015/062)