94 research outputs found
state of the art and perspectives of inorganic photovoltaics
In the last decade, the fast increase of the global energy consumption, mainly related to the strong economic growth in the Far East, and the progressive depletion of the fossil fuels induced a run-up in the world oil price. Both these economic concerns and the growing global pollution pointed out that a transition toward renewable energies is mandatory. Among renewables, the conversion of sunlight into electricity by photovoltaic (PV) devices is a reliable choice to cope the growing energy consumption, due to the huge potentially extractable power (up to 120000 TW). The most important classes of inorganic PV devices developed in the last sixty years will be reviewed in this paper, in order to depict the state of the art of the technologies which dominate the PV market. Some novel concepts which could have an important role in the future of PV will be also described
Geokinematics of Central Europe: New insights from the CERGOP-2/Environment Project
The Central European Geodynamics Project CERGOP/2, funded by the European Union from 2003to 2006 under the 5th Framework Programme, benefited from repeated measurements of thecoordinates of epoch and permanent GPS stations of the Central European GPS Reference Network(CEGRN), starting in 1994. Here we report on the results of the systematic processing of availabledata up to 2005. The analysis has yielded velocities for some 60 sites, covering a variety of CentralEuropean tectonic provinces, from the Adria indenter to the Tauern window, the Dinarides, thePannonian Basin, the Vrancea seismic zone and the Carpathian Mountains. The estimated velocitiesdefine kinematical patterns which outline, with varying spatial resolution depending on the stationdensity and history, the present day surface kinematics in Central Europe. Horizontal velocities areanalyzed after removal from the ITRF2000 estimated velocities of a rigid rotation accounting forthe mean motion of Europe: a ~2.3 mm/yr north-south oriented convergence rate between Adria andthe Southern Alps that can be considered to be the present day velocity of the Adria indenterrelative to the European foreland. An eastward extrusion zone initiates at the Tauern Window. Thelateral eastward flow towards the Pannonian Basin exhibits a gentle gradient from 1-1.5 mm/yrimmediately east of the Tauern Window to zero in the Pannonian Basin. This kinematic continuityimplies that the Pannonian plate fragment recently suggested by seismic data does not require aspecific Eulerian pole. On the southeastern boundary of the Adria microplate, we report a velocitydrop from 4-4.5 mm/yr motion near Matera to ~1 mm/yr north of the Dinarides, in the southwesternpart of the Pannonian Basin. A positive velocity gradient as one moves south from West Ukraineacross Rumania and Bulgaria is estimated to be 2 mm/yr on a scale of 600-800 km, as if the crustwere dragged by the counterclockwise rotation along the North Anatolian Fault Zone. This regimeapparently does not interfere with the Vrancea seismic zone: earthquakes there are sufficiently deep(> 100 km) that the brittle deformation at depth can be considered as decoupled from the creep atthe surface. We conclude that models of the Quaternary tectonics of Central and Eastern Europeshould not neglect the long wavelength, nearly aseismic deformation affecting the upper crust in theRomanian and Bulgarian regions
Social Security and Retirement During Transition: Microeconometric Evidence from Slovenia
Characteristics of patients with giant cell arteritis who experience visual symptoms
Permanent vision loss is one of the most serious complications of giant cell arteritis (GCA) and therefore prompt diagnosis is paramount. However, diagnosis of GCA remains challenging due to its frequently non-specific presentation. Our aim was to identify differences in the characteristics of GCA patients with, and without, current visual symptoms. A cross-sectional survey was mailed to patients with a GCA Read code entered in their GP electronic medical record. Responders were categorised as those currently reporting a visual symptom or not. We compared general and GCA-specific characteristics in these two groups. The association of diagnostic delay with subsequent experience of visual symptoms was examined using unadjusted and adjusted linear regression analysis. 318 GCA patients responded to the survey (59.6%). Responders were predominantly female (69.8%), with a mean age of 73.7 years (SD 8.2). 28% reported current visual symptoms. There was no statistically significant difference in the general characteristics between those with and without visual symptoms. Of GCA-specific characteristics, pre-GCA diagnosis of diplopia (p = 0.018), temporary (p ≤ 0.001) or permanent visual problems (p = 0.001) and hoarseness (p = 0.004) were more common among those reporting current visual symptoms. There was no association between the extent of diagnostic delay and reporting of current visual symptoms. Though we found few characteristics to distinguish between GCA patients with or without current visual symptoms, diagnostic delay was not associated with current visual symptoms. Our findings highlighted the continued difficulty for clinicians to identify GCA patients at the highest risk of visual complications
The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase
Instrumentatio
A novel endogenous antimalarial : Fe(II)-protoporphyrin IXα (heme) inhibits hematin polymerization to β-hematin (malaria pigment) and kills malaria parasites
The polymerization of hemoglobin-derived ferric-protoporphyrin IX [Fe(III)PPIX] to inert hemozoin (malaria pigment) is a crucial and unique process for intraerythrocytic plasmodia to prevent heme toxicity and thus a good target for new antimalarials. Quinoline drugs, i.e., chloroquine, and non-iron porphyrins have been shown to block polymerization by forming electronic \u3c0-\u3c0 interactions with heme monomers. Here, we report the identification of ferrous-protoporphyrin IX [Fe(II)PPIX] as a novel endogenous anti-malarial. Fe(II)PPIX molecules, released from the proteolysis of hemoglobin, are first oxidized and then polymerized to hemozoin. We obtained Fe(II)PPIX on preparative scale by electrochemical reduction of Fe(III)PPIX, and the reaction was monitored by cyclic voltammetry. Polymerization assays at acidic pH were conducted with the resulting Fe(II)PPIX using a spectrophotometric microassay of heme polymerization adapted to anaerobic conditions and the products characterized by infrared spectroscopy. Fe(II)PPIX (a) did not polymerize and (b) produced a dose- dependent inhibition of Fe(III)PPIX polymerization (IC50 = 0.4 molar equiv). Moreover, Fe(II)PPIX produced by chemical reduction with thiol- containing compounds gave similar results: a dose-dependent inhibition of heme polymerization was observed using either L-cysteine, N-acetylcysteine, or DL-homocysteine, but not with L-cystine. Cyclic voltammetry confirmed that the inhibition of heme polymerization was due to the Fe(II)PPIX molecules generated by the thiol-mediated reduction of Fe(III)PPIX. These results point to Fe(II)PPIX as a potential endogenous antimalarial and to Fe(III)PPIX reduction as a potential new pharmacological target
Influence of aluminium on solidification structure and initial deformability of continuously cast C–Mn–Si–N steel
Bacterial community shift is induced by dynamic environmental parameters in a changing coastal ecosystem (northern Adriatic, northeastern Mediterranean Sea) - a 2-year time-series study
The potential link between the microbial dynamics and the environmental parameters was investigated in a semi-enclosed and highly dynamic coastal system (Gulf of Trieste, northern Adriatic Sea, NE Mediterranean Sea). Our comprehensive 2-year time-series study showed that despite the shallowness of this area, there was a significant difference between the surface and the bottom bacterial community structure. The bottom bacterial community was more diverse than the surface one and influenced by sediment re-suspension. The surface seawater temperature had a profound effect on bacterial productivity, while the bacterial community structure was more affected by freshwater-borne nutrients and phytoplankton blooms. Phytoplankton blooms caused an increase of Gammaproteobacteria (Alteromonadaceae, SAR86 and Vibrionaceae) and shift in dominance from SAR11 to Rhodobacteraceae taxon at the surface. Our results propose the importance of the water mass movements as drivers of freshwater-borne nutrients and of allochthonous microbial taxa. This study emphasizes the prediction power based on association networks analyses that are fed with long-term measurements of microbial and environmental parameters. These interaction maps offer valuable insights into the response of marine ecosystem to climate- and anthropogenic-driven stressors
The relative influence of dynamic and static precipitation on the hot ductility of microalloyed steels
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