81 research outputs found
Campagna di sperimentazione del PPP a cura dello IEN e di NRCan
No full textRapporto Tecnico IEN n. 690, giugno 200
Il Precise Point Positioning: confronto a distanza di orologi mediante ricevitori GPS per geodesia
No full textRapporto Tecnico IEN n. 68
Performance Comparison and Stability Characterization of Timing and Geodetic GPS Receivers at IEN
No full textCharacterization of calcium carbonate nanoparticles with architectural application for the consolidation of Pietraforte
No full textSynthesis and characterization of Nb 2 O 5 mesostructures with tunable morphology and their application in dye-sensitized solar cells
No full textMesoporous submicrometric particles of orthorhombic Nb2O5 were prepared by a very simple route
consisting in the hydrolysis of niobium ethoxide Nb(OEt)5 in an alcoholic medium containing 1-
hexadecylamine as structure-directing agent followed by a hydrothermal treatment. The effects
related to the variation of the length of the aliphatic chain of the alcohol solvent (C2 to C4) and the
ramification of the alcohol (primary, secondary and tertiary), as well as the reactants to solvent ratio
were analyzed in terms of morphology, crystal structure, specific surface area and porosity. The obtained
solids, once thermally treated to remove the organics, were thoroughly characterized by powder XRD,
UV-Vis spectroscopy (band gap measurement), photovoltage measurements (conduction band edge
determination), BET-BJH surface analysis and FESEM. By simply modifying the solvent and reactants/
solvent ratio, different morphologies spanning from nearly monodisperse beads to peanut-shaped particles,
sintered spheres aggregates, a mix of different morphologies can be achieved. The obtained materials
were tested as photoanodes in dye-sensitized solar cells. After the optimization of the thickness of
the photoanode and of its chemical treatment in order to improve the inter-particle connections, DSSCs
were prepared by using N719 dye and a non-volatile iodide-based electrolyte. The cells were tested by J-V
curves under AM 1.5 G illumination and dark, IPCE measurements and electrochemical impedance
spectroscopy. A remarkable efficiency value of 3.4% under 1 sun illumination was achieved by employing
peanut-shaped particles obtained by using 2-propanol as solvent with the highest used reactant/solvent
ratio
The catalytic activity of Cu-ZSM-5 and Cu-Y zeolites in NO decomposition: dependence on copper concentration
No full textNO decomposition was studied on Cu-ZSM-5 (Cu exchange extent from 23 to 210%) and Cu-Y (Cu exchange extent from 5 to 105%) catalysts at 773 K. The results show that the activity (NO molecules decomposed per gram of catalyst per second) increases by roughly 100-fold when the extent of exchange with copper in the ZSM-5 framework increases from 80 to 100%. This behaviour shows that not all Cu sites are equivalent in their decomposition activity. Cu-ZSM-5 samples prepared with either H-ZSM-5 or Na-ZSM-5 show the same activity pattern
A SIMULTANEOUS CALIBRATION OF THE IEN/PTB TIME LINK BY GPS CV AND TWSTFT PORTABLE EQUIPMENT
No full textDetermination of the enrichment of the hydrogen bound to carbon 5 of glucose on (H2O)-H-2 administration
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