Electrochemical Impedance Spectroscopy study on ammonia-fed Solid Oxide Fuel Cells

The use of ammonia as a fuel is one of the promising pathways to decarbonize the energy sector. When ammonia is converted into power in the so-called "Ammonia-to-Power", the most interesting technology is the Solid Oxide Fuel Cell (SOFC) that can operate directly with ammonia and reach high performance in terms of efficiency. SOFCs are a high-efficiency and, potentially, low-cost technology, but still suffer from degradation issues related to internal losses. An innovative experimental technique to evaluate losses evolution caused by degradation is electrical impedance spectroscopy (EIS), followed by measurement data post-processing through the Distribution of Relaxation Times (DRT) analysis. In this study, a single SOFC is studied with a combined EIS and DRT methodology, when operating with a gas mixture of hydrogen, nitrogen and ammonia. The results identify the contribution to DRT of fuel dilution and the internal ammonia decomposition reaction

A superfluid-droplet crystal and a free-space supersolid in a dipole-blockaded gas

A novel supersolid phase is predicted for an ensemble of Rydberg atoms in the dipole-blockade regime, interacting via a repulsive dipolar potential "softened" at short distances. Using exact numerical techniques, we study the low temperature phase diagram of this system, and observe an intriguing phase consisting of a crystal of mesoscopic superfluid droplets. At low temperature, phase coherence throughout the whole system, and the ensuing bulk superfluidity, are established through tunnelling of identical particles between neighbouring droplets.Comment: 4 pages, 4 figure

SOFC Micro-CHP integration in residential buildings

SOFC technology has reached many of the performance goals that where indicated by scientific society and is providing several application that permits market penetration. One of the main targets is related to Micro Cogeneration Heat and Power (μ-CHP) for residential application. The integration of this system with a residential house has to be deeply investigated to individuate market targets in terms of costs and efficiency. This study evaluates the Italian market condition and analyzes the integration possibility with both thermal and electrical systems. Different solutions are investigated evaluating thermal and electrical driven logic for μ-CHP SOFC based unit and the opportunity of integration with local electrical grid. Evaluation on heat and electricity storage was also considered as integration strategy. The study is based on electrical and thermal loads in typical residential users and the evaluation is based on Italian technical standards and guidelines. Several operating conditions were evaluated and compared to obtain an optimized size and integration of μHP SOFC based solution

Hard X-ray polarimetry using scintillators

The linear polarization of the radiation from celestial sources can be investigated by studying the angular distribution of Compton scattered photons in a detection device. In this contribution we present the design of a Compton polarimeter based on the technology of fiber-shaped scintillators. A total geometric area of 1000 cm2 or more could be obtained by repeating a basic polarimeter composed by several fiber-like scintillators, some of them of low Z, acting as active scatterers, and others of high Z, acting as detectors. Polarimetric measurements can thus be carried out by searching for coincidences between a scatterer fiber and an absorber one. Monte Carlo simulations of the performances of such a device, when employed onboard a stratospheric balloon, are compared with other kinds of X-ray polarimeters

Characterization of active fault scarps from LiDAR data: a case 1 study from Central 2 Apennines (Italy)

A high resolution DEM (1 ms spacing) derived from an airborne LiDAR campaign was 11 used in an attempt to characterize the structural and erosive elements of the geometry of the Pettino 12 fault, a seismogenic normal fault in Central Apennines (Italy). Four 90- to 280 m -long fault scarp 13 segments were selected and the surface between the base and the top of the scarps was analyzed 14 through the statistical analysis of the following DEM-derived parameters: altitude, height of the 15 fault scarp, distance along strike, slope and aspect. The results identify slopes of up to 40° in faults 16 lower reaches interpreted as fresh faces, 34° up the faces. The Pettino fault maximum long slipe17 rate (0.6-1.1 mm/yr) was estimated from the scarp heights, which are up to 12 and 19 m in the 18 selected four segments, and the age (ca. 18 ka) of the last glacial erosional phase in the area. The 19 combined analysis of the DEM-derived parameters allow us to (a) define aspects of 3D scarp 20 geometry, (b) decipher its geomorphological significance, and (c) estimate the long-term slip rate

Mantle wedge dynamics vs crustal seismicity in the Apennines (Italy)

In the Apennines subduction (Italy), earthquakes mainly occur within overriding plate, along the chain axis. The events concentrate in the upper 15 km of the crust above the mantle wedge and focal solutions indicate normal faulting. In the foreland, the seismogenic volume affects the upper 35 km of the crust. Focal solutions indicate prevailing reverse faulting in the northern foreland and strike-slip faulting in the southern one. The deepening of the seismogenic volume from the chain axis to the foreland follows the deepening of the Moho and isotherms. The seismicity above the mantle wedge is associated with uplift of the chain axial zone, volcanism, high CO2 flux, and extension. The upward pushing of the asthenospheric mantle and the mantle-derived, CO2-rich fluids trapped within the crust below the chain axis causes this seismicity. All these features indicate that the axial zone of Apennines is affected by early rifting processes. In northern Italy, the widespread and deeper seismicity in the foreland reflects active accretion processes. In the southern foreland, the observed dextral strike-slip faulting and the lack of reverse focal solutions suggest that accretion processes are not active at present. In our interpretation of the Apennines subduction, the shallower seismicity of the overriding plate is due to the dynamics (uprising and eastward migration) of the asthenospheric wedge

IMP dehydrogenase inhibitor, tiazofurin, induces apoptosis in K562 human erythroleukemia cells.

none8Tiazofurin, an anticancer drug which inhibits IMP dehydrogenase, decreases cellular GTP concentration, induces differentiation and down-regulates ras and myc oncogene expression, caused apoptosis of K562 cells in a time- and dose-dependent fashion. Apoptotic cells were detected by (1) flow cytometry, (2) electron microscopy, and (3) fluorescence in situ nick translation and confocal microscopy, while the DNA ladder was not detectable. The induced apoptosis was abrogated by guanosine which replenishes GTP pools through the guanosine salvage pathways, while it was enhanced by hypoxanthine, a competitive inhibitor of GPRT. The tiazofurin-mediated apoptosis may therefore be linked with the decrease of GTP and the consequent impairment of specific signal transduction pathways. Tiazofurin induced apoptosis also in lymphoblastic MOLT-4 cells, suggesting that this action is not confined to cells of the myeloid lineage, where the differentiating effects of the drug are more pronounced.openVITALE M; ZAMAI L; FALCIERI E; ZAULI G; GOBBI P.; SANTI S; CINTI C; WEBER GVitale, M; Zamai, Loris; Falcieri, Elisabetta; Zauli, G; Gobbi, Pietro; Santi, S; Cinti, C; Weber, G

Normal faults and thrusts re-activated by deep fluids: the 6 April 2009 Mw 6.3 L’Aquila earthquake, central Italy.

On April 6 2009, a Mw=6.3 earthquake occurred in the central Apennines (Italy) damaging L’Aquila city and the surrounding country. We relocate the October 2008-April 6 2009 foreshocks and about 2000 aftershocks occurred between April 6 and April 30 2009, by applying a double-difference technique and determine the stress field from focal mechanisms. The events concentrate in the upper 15 km of the crust. Three main NW-SE to NNW-SSE striking, 30°-45° and 80°-90° dipping faults activate during the seismic sequence. Among these, a normal fault and a thrust were re-activated with dip-slip movements in response to NE-SW extension. The structural maturity of the seismogenic fault system is lower than that displayed by other systems in southern Apennines, because of the lower strain rate of the central sector of the chain with respect to the southern one. VP/VS increases progressively from October 2008 to the April 6 2009 mainshock occurrence along a NW-SE strike due to an increment in pore fluid pressure along the fault planes. Pore pressure diffusion controls the space-time evolution of aftershocks. A hydraulic diffusivity of 80 m2/s and a seismogenic permeability of about 10-12 m2 suggest the involvement of gas-rich (CO2) fluids within a highly fractured medium. Suprahydrostatic, high fluid pressure (about 200 MPa at 10 km of depth) within overpressurized traps, bounded by pre-existing structural and/or lithological discontinuities at the lower-upper crust boundary, are required to activate the April 2009 sequence. Traps are the storage zone of CO2-rich fluids uprising from the underlying, about 20 km deep, metasomatized mantle wedge. These traps easily occur in extensional regimes like in the axial sector of Apennines, but are difficult to form in strike-slip regimes, where sub-vertical faults may cross the entire crust. In the Apennines, fluids may activate faults responsible for earthquakes up to Mw=5-6. Deep fluids more than tectonic stress may control the seismotectogenesis of accretionary wedges

Investigation of the active Celano-L'Aquila fault system, Abruzzi (central Apennines, Italy) with combined ground-penetrating radar and palaeoseismic trenching

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