Use of nanomaterials to conserve the stone of the Roman Theatre of Cartagena

[EN] The Roman Theatre of Cartagena is an important example of the monumental architecture of Hispania. Various types of local stone were used in its construction, including a type of sandstone known as Tabaire. This paper describes the physical characteristics of Tabaire. We also identify its deterioration patterns and study its consolidation using lime nanoparticles and silicon dioxide (ethyl silicate). Initial analyses using the imaging techniques Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and X-Ray Tomography (CT) show that it is an extremely porous, soft stone. The effectiveness of the consolidating treatments was verified using non-destructive methods based on identifying dispersion and penetrability in the substrate (OM and SEM) and detecting colour variation (CIE-L*a*b*) or minimally destructive methods, such as the peeling test and Shore-D hardness, to determine their effect on the characteristics of the material.[ES] El Teatro de Cartagena es un importante exponente de la arquitectura monumental de la Hispania romana. Para su construcción fueron utilizados diversos pétreos locales, entre ellos una arenisca conocida como Tabaire. Este artículo tiene como objetivo la caracterización física del Tabaire, así como la identificación de sus formas de deterioro y el estudio de su consolidación mediante nanopartículas de cal y de dióxido de silicio (silicato de etilo). Los análisis iniciales mediante técnicas de imagen como la Microscopía Óptica (OM), Microscopía Electrónica de Barrido (SEM) y Tomografía de Rayos X (CT) muestran que es una roca de elevada porosidad y escasa dureza. La eficacia de los tratamientos consolidantes se comprobó mediante métodos no destructivos, basados en la identificación de la dispersión y penetrabilidad en el sustrato (OM y SEM) y en la detección de la variación del color (CIE-L*a*b*), o mínimamente destructivos, como el peeling test y la dureza Shore-D, para conocer su incidencia en las características del material.Navarro-Moreno, D.; Martínez-Arredondo, A.; García-Vera, VE.; Lanzón, M. (2023). Uso de nanomateriales para la conservación de la piedra del Teatro Romano de Cartagena. Loggia, Arquitectura & Restauración. (36):106-119. https://doi.org/10.4995/loggia.2023.193601061193

Diode area melting single-layer parametric analysis of 316L stainless steel powder

Diode area melting (DAM) is a novel additive manufacturing process that utilises customised architectural arrays of low power laser diode emitters for high speed parallel processing of metallic powdered feedstock. The laser diodes operate at shorter laser wavelengths (808 nm) than conventional SLM fibre lasers (1064 nm) theoretically enabling more efficient energy absorption for specific materials. This investigation presents a parametric analysis of the DAM process, identifying the effect of powder characteristics, laser beam profile, laser power and scan speed on the porosity of a single-layer sample. Also presented is the effect of process energy density on melt pool depth (irradiated thermal energy penetration capable of achieving melting) on 316L stainless steel powder. An analysis of the density and the melt depth fraction of single layers is presented in order to identify the conditions that lead to the fabrication of fully dense DAM parts. Energy densities in excess of 86 J/mm3 were theorised as sufficient to enable processing of fully dense layers

Cloning and expression analysis of hemoglobin genes from maize (\u3ci\u3eZea mays\u3c/i\u3e ssp. \u3ci\u3emays\u3c/i\u3e) and teosinte (\u3ci\u3eZea mays\u3c/i\u3e ssp. \u3ci\u3eparviglumis\u3c/i\u3e)

With the exception of barley and rice, little is known about the existence of hemoglobins (Hbs) in cereals. This work reports the cloning and analysis of hb genes from maize (Zea mays ssp. mays) and teosinte (Zea mays ssp. parviglumis). Coding sequences of maize and teosinte hb genes (hbm and hbt, respectively) are highly similar to each other and are interrupted by three introns located at identical positions as other plant hb genes. Sequences of predicted Hbm and Hbt proteins are identical. The hydropathic profile of Hbm and Hbt is highly similar to that of rice Hb1, suggesting that Hbm, Hbt and Hb1 have the same tertiary structure and biochemical properties. Expression analysis showed that low levels of Hb transcripts, but considerable levels of Hb proteins exist in maize embryonic organs. No Hb transcripts and proteins were detected in teosinte embryonic organs. Low levels of Hb proteins, but no Hb transcripts, were detected in maize and teosinte vegetative organs. These observations suggest that the regulation of hb genes is different in maize and teosinte embryonic organs, and that the expression of hb genes is down- or up-regulated in maize and teosinte, respectively, from germination to vegetative growing

Cloning and expression analysis of hemoglobin genes from maize (\u3ci\u3eZea mays\u3c/i\u3e ssp. \u3ci\u3emays\u3c/i\u3e) and teosinte (\u3ci\u3eZea mays\u3c/i\u3e ssp. \u3ci\u3eparviglumis\u3c/i\u3e)

With the exception of barley and rice, little is known about the existence of hemoglobins (Hbs) in cereals. This work reports the cloning and analysis of hb genes from maize (Zea mays ssp. mays) and teosinte (Zea mays ssp. parviglumis). Coding sequences of maize and teosinte hb genes (hbm and hbt, respectively) are highly similar to each other and are interrupted by three introns located at identical positions as other plant hb genes. Sequences of predicted Hbm and Hbt proteins are identical. The hydropathic profile of Hbm and Hbt is highly similar to that of rice Hb1, suggesting that Hbm, Hbt and Hb1 have the same tertiary structure and biochemical properties. Expression analysis showed that low levels of Hb transcripts, but considerable levels of Hb proteins exist in maize embryonic organs. No Hb transcripts and proteins were detected in teosinte embryonic organs. Low levels of Hb proteins, but no Hb transcripts, were detected in maize and teosinte vegetative organs. These observations suggest that the regulation of hb genes is different in maize and teosinte embryonic organs, and that the expression of hb genes is down- or up-regulated in maize and teosinte, respectively, from germination to vegetative growing

Element-Specific Depth Profile of Magnetism and Stoichiometry at the La0.67Sr0.33MnO3/BiFeO3 Interface

Depth-sensitive magnetic, structural and chemical characterization is important in the understanding and optimization of novel physical phenomena emerging at interfaces of transition metal oxide heterostructures. In a simultaneous approach we have used polarized neutron and resonant X-ray reflectometry to determine the magnetic profile across atomically sharp interfaces of ferromagnetic La0.67Sr0.33MnO3 / multiferroic BiFeO3 bi-layers with sub-nanometer resolution. In particular, the X-ray resonant magnetic reflectivity measurements at the Fe and Mn resonance edges allowed us to determine the element specific depth profile of the ferromagnetic moments in both the La0.67Sr0.33MnO3 and BiFeO3 layers. Our measurements indicate a magnetically diluted interface layer within the La0.67Sr0.33MnO3 layer, in contrast to previous observations on inversely deposited layers. Additional resonant X-ray reflection measurements indicate a region of an altered Mn- and O-content at the interface, with a thickness matching that of the magnetic diluted layer, as origin of the reduction of the magnetic moment.Comment: 13 pages, 4 figures, supplemental material include

Nonsymbiotic hemoglobins in rice are synthesized during germination and in differentiating cell types

Nonsymbiotic hemoglobins (ns-Hbs) previously have been found in monocots and dicots; however, very little is known about the tissue and cell type localization as well as the physiological function(s) of these oxygen-binding proteins. We report the immunodetection and immunolocalization of ns-Hbs in rice (Oryza sativa L.) by Western blotting and in situ confocal laser scanning techniques. Ns-Hbs were detected in soluble extracts of different tissues from the developing rice seedling by immunoblotting. Levels of ns-Hbs increased in the germinating seed for the first six days following imbibition and remained relatively constant thereafter. In contrast, ns-Hb levels decreased during leaf maturation. Roots and mesocotyls contained detectable, but low levels of ns-Hbs. Split-seed experiments revealed that ns-Hbs are synthesized de novo during seed germination and are expressed in the absence of any signal originating from the embryo. Immunolocalization of ns-Hbs by con- focal microscopy indicated the presence of ns-Hbs primarily in differentiated and differentiating cell types of the developing seedling, such as the aleurone, scutellum, root cap cells, sclerenchyma, and tracheary elements. To our knowledge, this is the first report of the specific cellular localization of these proteins during seedling development

Nonsymbiotic hemoglobins in rice are synthesized during germination and in differentiating cell types

Nonsymbiotic hemoglobins (ns-Hbs) previously have been found in monocots and dicots; however, very little is known about the tissue and cell type localization as well as the physiological function(s) of these oxygen-binding proteins. We report the immunodetection and immunolocalization of ns-Hbs in rice (Oryza sativa L.) by Western blotting and in situ confocal laser scanning techniques. Ns-Hbs were detected in soluble extracts of different tissues from the developing rice seedling by immunoblotting. Levels of ns-Hbs increased in the germinating seed for the first six days following imbibition and remained relatively constant thereafter. In contrast, ns-Hb levels decreased during leaf maturation. Roots and mesocotyls contained detectable, but low levels of ns-Hbs. Split-seed experiments revealed that ns-Hbs are synthesized de novo during seed germination and are expressed in the absence of any signal originating from the embryo. Immunolocalization of ns-Hbs by con- focal microscopy indicated the presence of ns-Hbs primarily in differentiated and differentiating cell types of the developing seedling, such as the aleurone, scutellum, root cap cells, sclerenchyma, and tracheary elements. To our knowledge, this is the first report of the specific cellular localization of these proteins during seedling development

Collimated Outflow Formation via Binary Stars. 3-D Simulations of AGB Wind and Disk Wind Interactions

We present three-dimensional hydrodynamic simulations of the interaction of a slow wind from an asymptotic giant branch(AGB) star and a jet blown by an orbiting companion. The jet or "Collimated Fast Wind" is assumed to originate from an accretion disk which forms via Bondi accretion of the AGB wind or Roche lobe overflow. We present two distinct regimes in the wind-jet interaction determined by the ratio of the AGB wind to jet momentum flux. Our results show that when the wind momentum flux overwhelms the flux in the jet a more dis-ordered outflow outflow results with the jet assuming a corkscrew pattern and multiple shock structures driven into the AGB wind. In the opposite regime the jet dominates and will drive a highly collimated narrow waisted outflow. We compare our results with scenarios described by Soker & Rappaport (2000) and extrapolate the structures observed in PNe and Symbiotic stars.Comment: 22 pages, 8 figures, submitted to Ap