Intercomparison of spectroradiometers and Sun photometers for the determination of the aerosol optical depth during the VELETA-2002 field campaign

[ 1] In July 2002 the VELETA-2002 field campaign was held in Sierra Nevada ( Granada) in the south of Spain. The main objectives of this field campaign were the study of the influence of elevation and atmospheric aerosols on measured UV radiation. In the first stage of the field campaign, a common calibration and intercomparison between Licor-1800 spectroradiometers and Cimel-318 Sun photometers was performed in order to assess the quality of the measurements from the whole campaign. The intercomparison of the Licor spectroradiometers showed, for both direct and global irradiances, that when the comparisons were restricted to the visible part of the spectrum the deviations were within the instruments' nominal accuracies which allows us to rely on these instruments for measuring physical properties of aerosols at the different measurement stations. A simultaneous calibration on AOD data was performed for the Cimel-318 Sun photometers. When a common calibration and methodology was applied, the deviation was lowered to much less than 0.01 for AOD. At the same time an intercomparison has been made between the AOD values given by the spectroradiometers and the Sun photometers, with deviations obtained from 0.01 to 0.03 for the AOD in the visible range, depending on the channel. In the UVA range, the AOD uncertainty was estimated to be around 0.02 and 0.05 for Cimel and Licor respectively. In general the experimental differences were in agreement with this uncertainty estimation. In the UVB range the AOD measurements should not be used due to maximum instrumental uncertainties

Evaluation of the new ESR network software for the retrieval of direct sun products from CIMEL CE318 and PREDE POM01 sun-sky radiometers

The European Skynet Radiometers network (EuroSkyRad or ESR) has been recently established as a research network of European PREDE sun-sky radiometers. Moreover, ESR is federated with SKYNET, an international network of PREDE sun-sky radiometers mostly present in East Asia. In contrast to SKYNET, the European network also integrates users of the CIMEL CE318 sky–sun photometer. Keeping instrumental duality in mind, a set of open source algorithms has been developed consisting of two modules for (1) the retrieval of direct sun products (aerosol optical depth, wavelength exponent and water vapor) from the sun extinction measurements; and (2) the inversion of the sky radiance to derive other aerosol optical properties such as size distribution, single scattering albedo or refractive index. In this study we evaluate the ESR direct sun products in comparison with the AERosol RObotic NETwork (AERONET) products. Specifically, we have applied the ESR algorithm to a CIMEL CE318 and PREDE POM simultaneously for a 4-yr database measured at the Burjassot site (Valencia, Spain), and compared the resultant products with the AERONET direct sun measurements obtained with the same CIMEL CE318 sky–sun photometer. The comparison shows that aerosol optical depth differences are mostly within the nominal uncertainty of 0.003 for a standard calibration instrument, and fall within the nominal AERONET uncertainty of 0.01–0.02 for a field instrument in the spectral range 340 to 1020 nm. In the cases of the Ångström exponent and the columnar water vapor, the differences are lower than 0.02 and 0.15 cm, respectively. Therefore, we present an open source code program that can be used with both CIMEL and PREDE sky radiometers and whose results are equivalent to AERONET and SKYNET retrievals

2D experiments and numerical simulation of the oscillatory shallow flow in an open channel lateral cavity

Steady shallow flows past an open channel lateral cavity can induce the excitation of an eigenmode of a gravity standing wave inside the cavity, called seiche, which may be coupled with the shedding of vortices at the opening of the cavity. The presence of the seiche is of fundamental interest as it enhances the mass exchange between the main channel and the cavity. Measurements of the time evolution of the water surface are not often found in the literature for this type of flows. In this work, an experimental and numerical study of a shallow flow past a channel lateral cavity is carried out. The main novelty is the use of a pioneering non-intrusive experimental technique to measure the water surface at the channel-cavity region. This optical technique offers high resolution 2D data in time and space of the water surface evolution, allowing to determine the relevant features of the seiche oscillation. Such data are supplemented with Particle Image Velocimetry measurements. Furthermore, the experiments are numerically reproduced using a high-resolution depth-averaged URANS shallow water model, under the assumption that shallow water turbulence is mainly horizontal. The experimental and numerical results are analyzed in the frequency domain. High-resolution two-dimensional amplitude oscillation maps of the seiche phenomenon, as well as velocity fields, are presented. The high quality of the experimental data reported in this work makes this data set a suitable benchmark for numerical simulation models in order to evaluate their performance in the resolution of turbulent resonant shallow flows

A new perspective on Copper Age technology, economy and settlement: grinding tools at the Valencina mega‑site

Activity patterns at large prehistoric sites are often difficult to interpret, as they frequently combine productive, domestic and funerary components. Valencina, the largest of the Copper Age mega-sites in Iberia, has proved particularly challenging in this regard. Macrolithic tool assemblages have been generally neglected in these debates but can provide specific insight into the nature and patterning of activities. In this study, 185 grinding tools from seven separate excavations across this 450 ha mega-site were subjected to multiple lines of analysis including quantification, morphology, raw material, use-wear and depositional context. A surprising feature of this assemblage is the high degree of fragmentation, with more than half of the items representing less than 25% of the original artefact and only a small minority of them (< 10%) complete. The absence of intact quernstones is particularly striking. The results indicate a ritualization of deposition at Valencina, and throw new light on the interpretation of this complex site. Furthermore, they emphasize the central role that grinding technology should play in future discussion of European prehistoric mega-sites

Composite resins : A review of the materials and clinical indications

The aim of this work is to present the different components of the composites currently used in dentistry and furnish dentists with a basis that can provide criteria for choosing one or another to suit their therapeutic requirements. Most composites used in dentistry are hybrid materials, so-called because they are composed of polymer groups reinforced by an inorganic phase of glass fillers with different compositions, particle sizes and fill percentages. Flowable or condensable composites have attempted to provide an answer to certain functional requirements, although they have not been too successful at improving properties. Turning to polymerisation initiators, both halogen lamps, whether conventional or high intensity, and LED curing lights which provide a gradual increase in light intensity are very useful for reducing shrinkage of the composite material. The clinical choice of a composite must consider whether priority should be given to mechanical or aesthetic requirements: if mechanical considerations are paramount the material with the greatest volume of filler will be chosen; if aesthetic considerations predominate, particle size will be the most important factor. Additional components such as opaques and tints make it possible to improve the aesthetic results. Equally, the spread of other therapeutic procedures, such as tooth bleaching, has made it necessary to design composite materials in shades that are suitable for the special colour situations found in teeth treated by these methods

Thermodynamic aspects of partial miscibility between n-octanol and water

In the present work the thermodynamic analysis for those data presented by Dallos and Liszi on mole fraction n-octanol-water liquid-liquid equilibria was made. The values were analyzed using the van't Hoff method (ln S as a function of T-1) and those presented by Grant et al. (ln S as a function of T-1 and ln T). A non-lineal behavior was found in all cases studied by the van't Hoff method, which lead us to apply a parabolic regression model derived in order to calculate the enthalpic changes. Endothermic processes were obtained for all temperatures studied. In both systems the free energy changes were positive, whereas the entropic changes were negative indicating some kind of organization in the saturated solutions. In the case of n-octanol-saturated water this result would be explained as the hydrophobic hydration around the aliphatic groups and on the other hand, in the case of water-saturated n-octanol, it could be due to organization of n-octanol molecules around water molecules by hydrogen bonds as it has been presented in literature. The thermodynamic values calculated were compared with those presented by other authors, which were obtained by calorimetry and also by means of equilibrium constants as a function of temperature.En este trabajo se realizó el tratamiento termodinámico de los datos en fracción molar del equilibrio líquido-líquido entre n-octanol y agua en función de la temperatura, utilizando el método de van't Hoff (ln S en función de T-1) y el planteado por Grant et al. (ln S en función de T-1) y ln T: para las dos escalas de concentración. Se encontró un comportamiento no lineal para las dos fases mutuamente saturadas en el tratamiento de van't Hoff, por lo que se utilizó un modelo de regresión parabólico, que fue derivado para resolver el cambio entálpico de solución, obteniendo procesos endotérmicos a todas las temperaturas estudiadas. En los dos sistemas los cambios de energía libre fueron positivos mientras que los cambios entrópicos fueron negativos indicando algún grado de organización en las soluciones saturadas, que en el caso del agua saturada de n-octanol podría explicarse por la hidratación hidrofóbica en torno a las cadenas octílicas y en el caso del n-octanol saturado de agua podría deberse como ha sido planteado en la literatura a la organización de las moléculas del n-octanol entorno a las moléculas de agua mediante la formación de enlaces de hidrógeno. Los valores termodinámicos calculados fueron comparados con los presentados por otros autores, obtenidos por calorimetría y también, mediante evaluación de constantes de equilibro en función de la temperatura

Zinc-Assisted Microscale Granules Made of the SARS-CoV-2 Spike Protein Trigger Neutralizing, Antivirus Antibody Responses

Protein secretory granules; SARS-CoV-2; AntibodiesGránulos secretores de proteínas; SARS-CoV-2; AnticuerposGrànuls secretors de proteïnes; SARS-CoV-2; AnticossosThe development of new and more efficient vaccination approaches is a constant need, due to the pressure of historical and emerging infectious diseases and the limited efficacy and universality of the current vaccination technologies. Peptides and recombinant proteins have been explored for decades as subunit vaccines for bacterial and viral infections, presented either as soluble protein species or as virus-like assemblies. Recently, synthetic secretory protein-only microscale granules have been developed as dynamic depots for sustained protein release. They are based on the reversible coordination between ionic Zn and histidine residues, which promotes a fast formation of granular particles in vitro out of soluble protein and a slow release of such building block protein in vivo through the physiological chelation of the metal. Such an endocrine-like platform represents a new drug delivery system fully validated in oncology by which soluble and functional protein drugs are progressively released from the granules and made available for antitumor activities upon subcutaneous administration. By exploring such an approach for immunization here, microparticles made of a recombinant form of the receptor binding domain (RBD) of SARS-CoV-2 were tested as an antigen delivery system for induction of antibody responses against the virus upon administration of the material in the absence of added adjuvants. Also, the comparison between protein materials produced in bacterial, mammalian, or insect cell factories has demonstrated a moderate impact of protein glycosylation on the final immunological performance of the system. Therefore, we propose the consideration of synthetic protein secretory granules as a new sustainable immunization platform based on fully manageable, self-organized, and self-formulated immunogens, aimed at reducing the dosage, costs, and complexity of vaccination regimens.The authors appreciate the financial support received from AGAUR (2020PANDE00003 and 2021SGR00092 to A.V.), from CIBER-Consorcio Centro de Investigación Biomédica en Red- (CB06/01/0014), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación, through intramural projects (NANOSARS to E.P. and NANOREMOTE to E.V.). We also appreciate the support from AEI for the development of multimeric recombinant drugs (PID2019-105416RB-I00/AEI/10.13039/501100011033 and PDC2022-133858-I00 to E.V., PID2019-107298RB-C22 to N.F.-M., PID2020-116174RB-I00 to A.V. and PID2022-1368450 OB-10/AEI/10.13039/501100011033 to A.V. and E.V.). M.T.P.F. received a FAPESP fellowship (No. 2021/08528-0) and L.C.S.F. received a FAPESP research grant (No. 2020/05204-7). A.V. received an ICREA ACADEMIA award

Un estudio comparativo sobre el pensamiento profesional y la "acción docente" de los profesores de ciencias de Educación Secundaria. Parte II

Este artículo es la segunda parte de una investigación más amplia sobre el pensamiento del profesor (Martínez et al., 2001). En este caso el estudio gira en torno al análisis de las diferencias y similitudes entre dos muestras de profesores de ciencias de educación secundaria que difieren en sus años de docencia y en su trayectoria profesional, definida por la realización de cursos de formación permanente de alta cualificación científica y didáctica. En un primer apartado se analizan facetas relacionadas con la motivación y la satisfacción en la realización de su tarea, la manera de entender la formación del profesor y sus percepciones sobre diferentes factores profesionales. A continuación se aborda lo que «dicen hacer» en relación a aspectos curriculares referidos a contenidos, metodología y evaluación. A partir del análisis de las respuestas a los cuestionarios elaborados se plantean una serie de reflexiones que buscarían mejorar el «desarrollo profesional» de este colectivo de profesores.This article is a part of a wider research on secondary science teachers' beliefs. Through the use of a questionnaire data were obtained from 103 secondary science teachers in service with different degrees of experience. Analysis of data are discussed in terms of their implication in teacher training in service

¿Qué pensamiento profesional y curricular tienen los futuros profesores de ciencias de Secundaria?

This article is a part of a wider research on secondary science teachers' beliefs. Through the use of a questionnaire data were obtained from 211 secondary science teacher candidates. Analyses of data are discussed in terms of their implication in science teacher education

X-ray nanoimaging of Nd3+ optically active ions embedded in Sr0.5Ba0.5Nb2O6 nanocrystals

[EN] The spatial distribution of Sr0.5Ba0.5Nb2O6 nanocrystals is analyzed in a borate-based glass-ceramic by a synchrotron hard X-ray nanoimaging tool. Based on X-ray excited optical luminescence, we examined 2D projections of the Nd3+ optically active ions in the Sr0.5Ba0.5Nb2O6 nanocrystals, as well as in the glassy phase where they are embedded. Our findings reveal areas of agglomerations and/or clusters of nanocrystals ascribed to the diffusion coefficients of their constituent elements. They are characterized by high Nd3+ concentrations that may act as heterogeneous agents for the nucleation and growth of these nanocrystals. (C) 2017 Optical Society of AmericaMINECO, EU-FEDER and CSIC through the projects MAT2013-46649-C4-4-P, MAT201571070-REDC, MAT2016-75586-C4-2-P, MAT2016-75586-C4-4-P, 201550I021 and 201660I001, respectively. JAS acknowledges the Spanish Program Ramón y Cajal for his fellowship. 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