Abstract: The growing concern for the increase of the global warming effects due to anthropogenic activities raises the challenge of finding novel technological approaches to stabilize CO2 emissions in the atmosphere and counteract impinging interconnected issues such as desertification and loss of biodiversity. Biological-CO2 mitigation, triggered through biological fixation, is considered a promising and eco-sustainable method, mostly owing to its downstream benefits that can be exploited. Microorganisms such as cyanobacteria, green algae and some autotrophic bacteria could potentially fix CO2 more efficiently than higher plants, due to their faster growth. Some examples of the potential of biological-CO2 mitigation are reported and discussed in this paper. In arid and semiarid environments, soil carbon sequestration (CO2 fixation) by cyanobacteria and biological soil crusts is considered an eco-friendly and natural process to increase soil C content and a viable pathway to soil restoration after one disturbance event. Another way for biological-CO2 mitigation intensively studied in the last few years is related to the possibility to perform carbon dioxide sequestration using microalgae, obtaining at the same time bioproducts of industrial interest. Another possibility under study is the exploitation of specific chemotrophic bacteria, such as Ralstonia eutropha (or picketii) and related organisms, for CO2 fixation coupled with the production chemicals such as polyhydroxyalkanoates (PHAs). In spite of the potential of these processes, multiple factors still have to be optimized for maximum rate of CO2 fixation by these microorganisms. The optimization of culture conditions, including the optimal concentration of CO2 in the provided gas, the use of metabolic engineering and of dual purpose systems for the treatment of wastewater and production of biofuels and high value products within a biorefinery concept, the design of photobioreactors in the case of phototrophs are some of the issues that, among others, have to be addressed and tested for cost-effective CO2 sequestration.

Abstract: A combination of synchrotron radiation-based elementalimaging, in vivo redox status analysis, histology, and toxic responses was usedto investigate the uptake, biodistribution, and adverse effects of Cenanoparticles (CeO2NP; 10 nm; 0.5-34.96 mg Ce L-1) or Ce(NO3)3(2.3-26 mg Ce L-1)inCaenorhabditis elegans. Elemental mapping of theexposed nematodes revealed Ce uptake in the alimentary canal prior todepuration. Retention of CeO2NPs was low compared to that of Ce(NO3)3in depurated individuals. X-rayfluorescence (XRF) mapping showed that Cetranslocation was confined to the pharyngeal valve and foregut. Ce(NO3)3exposure significantly decreased growth, fertility, and reproduction, causedslightly reduced fecundity. XRF mapping and histological analysis revealedsevere tissue deformities colocalized with retained Ce surrounding thepharyngeal valve. Both forms of Ce activated the sod-1 antioxidant defense,particularly in the pharynx, whereas no significant effects on the cellular redox balance were identified. The CeO2NP-induceddeformities did not appear to impair the pharyngeal function or feeding ability as growth effects were restricted to Ce(NO3)3exposure. The results demonstrate the utility of integrated submicron-resolution SR-based XRF elemental mapping of tissue-specificdistribution and adverse effect analysis to obtain robust toxicological evaluations of metal-containing contaminants.

Abstract: This work provides values of electron scattering 002 structure factors for InxGa1-xAs as a function of the In concentration x=0 to 1. These results allow accurate compositional analysis of pseudomorphically grown InxGa1-xAs/GaAs layers by transmission electron microscopy methods relying on the chemical sensitivity of the (002) beam. The calculations go beyond the limits of the isolated atom approximation, because they take into account charge redistribution effects between atomic sites in the crystal, strain, and static atomic displacements. The computations were performed by the full potential linearized augmented plane-wave method using a generalized gradient approximation for the exchange and correlation part of the potential. The calculations of strained InxGa1-xAs correspond to the strain state in specimens with large, small, and intermediate thickness in the electron beam direction. Additionally, the effect of static atomic displacements is taken into account. All results are listed in a parameterized form. The calculated 002 structure factor vanishes at an In concentration of 16.4%. This value is in a good agreement with previously reported experimental measurements. Hence, our results are a significant improvement with respect to the isolated atom approximation which is conventionally applied in transmission electron microscopy simulations, and which predicts a value of 22.5%.

Abstract: Semiconductor heterostructures are used for the fabrication of optoelectronic devices. Performance of such devices is governed by their chemical morphology. The composition distribution of quantum wells and dots is influenced by kinetic growth processes which are not understood completely at present. To obtain more information about these effects, methods for composition determination with a spatial resolution at a near atomic scale are necessary. In this paper we focus on the present state of the composition evaluation by the lattice fringe analysis (CELFA) technique and explain the basic ideas, optimum imaging conditions, precision and accuracy.

Abstract: In this study, the interaction between cells and micron-sized paramagnetic iron oxide (MPIO) particles was investigated by characterizing MPIO in their original state, and after cellular uptake in vitro as well as in vivo. Moreover, MPIO in the olfactory bulb were studied 9months after injection. Using various imaging techniques, cell-MPIO interactions were investigated with increasing spatial resolution. Live cell confocal microscopy demonstrated that MPIO co-localize with lysosomes after in vitro cellular uptake. In more detail, a membrane surrounding the MPIO was observed by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). Following MPIO uptake in vivo, the same cell-MPIO interaction was observed by HAADF-STEM in the subventricular zone at 1week and in the olfactory bulb at 9months after MPIO injection. These findings provide proof for the current hypothesis that MPIO are internalized by the cell through endocytosis. The results also show MPIO are not biodegradable, even after 9months in the brain. Moreover, they show the possibility of HAADF-STEM generating information on the labeled cell as well as on the MPIO. In summary, the methodology presented here provides a systematic route to investigate the interaction between cells and nanoparticles from the micrometer level down to the nanometer level and beyond. Copyright (c) 2014 John Wiley Sons, Ltd.

Abstract: This study shows the first Raman microscopy (RM) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) characterization of two 14th and 15th century lead-glazed and luster ceramics from the Manises and Paterna workshops (Valencia, Spain) produced after the Aragon Christian conquest of the Iberian Peninsula (14th century). According to experts, these coetaneous ceramics were most probably involved in a process of technological transfer from the Islamic area of Southeast Spain to the Christian area of Valencia (East Spain) at the beginning of the 14th century; later on, the celebrated Manises and Paterna workshops were formed. Although these ceramics have been studied widely in terms of production technology (ceramic body, glazes and luster) using an array of diverse analytical techniques, until now, an RM study has not been carried out. This paper presents results regarding the complex chemical composition of the glaze and luster coloring agents, and the quality of color manufacturing processes, elucidating firing conditions via spectral components analysis (i.e., Q(n) for stretching/bending components) and polymerization index (Ip), emphasizing chronology and pigment technology changes between both Valencian workshops. Coloring agents identified in glazes and lusters were cobalt present in blue glazes, copper in greenish glazes, copper and cobalt in the turquoise glaze, and pyrolusite in black glazes. Tin oxyde was used as an opacifier in white glazes. Two luster manufacture recipes were recognized mainly based on copper and silver compounds. Calculated firing temperatures were up to 1000 degrees C for white glazes and up to 600 degrees C for luster and color glazes. Copyright (c) 2015 John Wiley & Sons, Ltd.

Abstract: In this work we present for the first time, to our knowledge, the CVD epitaxial growth of beta -SiC using an ion beam synthesized (IBS) beta -SiC layer as seed, which has been formed by multiple implantation into Si wafers at 500 degreesC. The ion beam synthesized continuous layer is constituted by beta -SiC nanocrystals that are well oriented relative to the silicon substrate. Comparison of the epitaxial growth on these samples with that on silicon test samples, both on and off-axis, is performed. The results show that the epitaxial growth can be achieved on the IBS samples without the need of the carbonization step and that the structural quality of the CVD layer is comparable to that obtained on a carbonized silicon sample. Improvement of the quality of the deposited layer is proposed.

Abstract: A superconducting rod with a magnetic moment on top develops vortices obtained here through 3D calculations of the GinzburgLandau theory. The inhomogeneity of the applied field brings new properties to the vortex patterns that vary according to the rod thickness. We find that for thin rods (disks) the vortex patterns are similar to those obtained in presence of a homogeneous magnetic field instead because they consist of giant vortex states. For thick rods novel patterns are obtained as vortices are curve lines in space that exit through the lateral surface.

Abstract: Dry deposition velocities have been calculated using three different approaches. Turbulent wind profile theory has been used to predict the drag coefficient, wind speed and friction velocity at 10 m height when the wind speed is measured at a higher altitude. The resulting parameters were introduced in a two-layer deposition model. The second approach was the well-known model of Slinn and Slinn (1980, Atmospheric Environment 14, 1013-1016), whereas the third corresponded to the model published by Williams (1982, Atmospheric Environment 16, 1933 1938). Results point to clear differences. However, in a field experiment carried out at the Southern Bight of the North Sea, all three approaches show relatively comparable results. The role played by the size distribution of atmospheric particulate matter is essential. In our case any of the three models could have given satisfactory outcomes taking into account the wide spread of the experimental results cited in the literature for the same airshed.