Promoting Renewable Energy in Longyearbyen: A Sustainable Means to Prevent Svalbard's Environmental Degradation

This study aims to separately investigate: 1.The political reasons behind Norway‟s controversial decision to encourage a coal enterprise on Svalbard (an archipelago in the Arctic) and, 2.The current and future potential of wind and solar energy as untapped renewable sources, locally exploited through a hybrid wind-PV system. In doing so this preliminary study attempts to provide insights for the implementation of an alternative, sustainable strategy to keep a Norwegian year-round settlement at Longyearbyen, Svalbard, without any recourse to polluting mining operations. Such an eventuality, despite the need for further research, is promisingly described as feasible, environmentally advantageous and politically conceivable

Shaping Copper Nanocatalysts to Steer Selectivity in the Electrochemical CO2 Reduction Reaction

The carbon-neutral production of fuels and chemical feedstocks is one of the grand challenges for our society to solve. The electrochemical conversion of CO2 is emerging as a promising technology contributing to this goal. Despite the huge amount of progress made over the past decade, selectivity still remains a challenge. This Account presents an overview of recent progress in the design of selective catalysts by exploiting the structural sensitivity of the electrochemical CO2 reduction reaction (CO2RR). In particular, it shows that the accurate and precise control of the shape and size of Cu nanocatalysts is instrumental in understanding and in discovering the structure-selectivity relationships governing the reduction of CO2 to valuable hydrocarbons, such as methane and ethylene. It further illustrates the use of faceted Cu nanocatalysts to interrogate catalytic pathways and to increase selectivity toward oxygenates, such as ethanol, in the framework of tandem schemes. The last part of the Account highlights the role of well-defined nanocatalysts in identifying reconstruction mechanisms which might occur during operation. An outlook for the emerging paradigms which will empower the design of novel catalysts for CO2RR concludes the Account

Formation and microscopic investigation of iron oxide aligned nanowires into polymeric nanocomposite films

We present a microscopic investigation of nanocomposite films of iron oxide (g-Fe2O3) magnetic nanowires (NWs) aligned into polymers, formed upon evaporation of solutions of acrylate polymer/magnetic nanoparticles under magnetic field (MF). The field causes the assembly of the g-Fe2O3 nanoparticles along the direction of the MF lines, resulting in magnetic NWs embedded throughout the entire volume of the polymer film. The scanning electron microscopy and the trans- mission electron microscopy studies show that the cylindrical-shaped NWs have � 15-lm average length and are isotropically distributed throughout the film. The study with the MF microscopy tech- nique not only proves that the composed NWs are magnetic but also makes possible the magnetic study of each individual NW in a nondestructive way. In this way it becomes possible for the localized study of the magnetic properties alteration after the binding of various molecules onto individual NWs, opening up the way of using these films in sensor devices applied in various fields ranging from biology to environmental purposes. Microsc. Res. Tech. 73:952-958, 2010. V C 2010 Wiley-Liss, Inc

Size, Shape, and Internal Atomic Ordering of Nanocrystals by Atomic Pair Distribution Functions: A Comparative Study of γ-Fe2O3 Nanosized Spheres and Tetrapods

Due to their limited length of structural coherence nanocrystalline materials show very diffuse powder X-ray diffraction patterns that are difficult to interpret unambiguously. We demonstrate that a combination of high-energy X-ray powder diffraction and atomic pair distribution function analysis can be used to both assess the geometry (i.e., size and shape) and determine the internal atomic ordering of nanocrystalline materials in a straightforward way. As an example we consider cubic γ-Fe2O3 nanosized crystals shaped as spheres and tetrapods

Colloidal Nanocrystals as Heterogeneous Catalysts for Electrochemical CO2 Conversions

In the past decade, atomically engineered nanomaterials with different sizes and exposed facets have been proven to be excellent model systems to advance catalytic studies. Colloidal chemistry is one of the most powerful wet-chemistry techniques to tailor-make nanomaterials, thus making colloidal nanocrystals an ideal playground to investigate structural and compositional reaction sensitivities but also to study degradation pathways. In this Perspective, we focus on colloidally synthesized nanocrystals as heterogeneous catalysts for the electrochemical CO2 reduction reaction. We discuss very recent studies from us and from others, which encourage the scientific community to explore the tunability offered by colloidal chemistry even further. For example, synergistic interactions of the metallic nanocrystal catalyst with domains of different chemical nature could be exploited with the aim of revealing new catalytic motifs that promote the activity, selectivity, and stability of electrocatalysts for CO2 conversion

Impaired Differentiation of Osteoclasts in TREM-2–deficient Individuals

TREM-2 is an immunoglobulin-like cell surface receptor associated with DAP12/KARAP that activates monocyte-derived dendritic cells (DCs) in vitro. Recently, it has been shown that genetic defects of human DAP12/KARAP and TREM-2 result in a rare syndrome characterized by bone cysts and presenile dementia called Nasu-Hakola disease. This observation suggests that TREM-2 may function in myeloid cells other than DCs, most probably osteoclasts (OCs) and microglial cells, which are involved in bone modeling and brain function. Consistent with this prediction, here we show that OC differentiation is dramatically arrested in TREM-2–deficient patients, resulting in large aggregates of immature OCs that exhibit impaired bone resorptive activity. These results demonstrate a critical role for TREM-2 in the differentiation of mononuclear myeloid precursors into functional multinucleated OCs