Heterogenized water oxidation catalysts prepared by immobilizing Klaui-type organometallic precursors

An efficient heterogenized water oxidation catalyst (2_TiO2) has been synthesized by immobilizing the Kläui-type organometallic precursor [Cp*Ir{P(O)(OH)2}3]Na (2, Cp*=1,2,3,4,5-pentamethylcyclopentadienyl ligand) onto rutile TiO2. Iridium is homogeneously distributed at the molecular and atomic/small cluster level in 2_TiO2 and 2'_TiO2 (solid catalyst recovered after the first catalytic run), respectively, as indicated by STEM-HAADF (scanning transmission electron microscopy - high angle annular dark field) studies. 2'_TiO2 exhibits TOF values up to 23.7 min-1 in the oxidation of water to O2 driven by NaIO4 at nearly neutral pH, and a TON only limited by the amount of NaIO4 used, as indicated by multiple run experiments. Furthermore, while roughly 40¿% leaching is observed during the first catalytic run, 2'_TiO2 does not undergo any further leaching even when in contact with strongly basic solutions and completely maintains its activity for thousands of cycles. NMR studies, in combination with ICP-OES (inductively coupled plasma optical emission spectrometry), indicate that the activation of 2_TiO2 occurs through the initial oxidative dissociation of PO43-, ultimately leading to active centers in which a 1:1 P/Ir ratio is present (derived from the removal of two PO43- units) likely missing the Cp* ligand.Peer ReviewedPostprint (author's final draft

Coro per La nave di Gabrieli d'Annunzio ; e, I pastori /

Reproduced from ms. (holograph?)"Supplément a La revue S.I.M. d'octobre 1911."The first work, an excerpt from incidental music for D'Annunzio's play, for chorus (ATT) with orchestral acc. arr. for piano; the 2nd work for voice and piano.Mode of access: Internet

Heterogenized water oxidation catalysts prepared by immobilizing Klaui-type organometallic precursors

An efficient heterogenized water oxidation catalyst (2_TiO2) has been synthesized by immobilizing the Kläui-type organometallic precursor [Cp*Ir{P(O)(OH)2}3]Na (2, Cp*=1,2,3,4,5-pentamethylcyclopentadienyl ligand) onto rutile TiO2. Iridium is homogeneously distributed at the molecular and atomic/small cluster level in 2_TiO2 and 2'_TiO2 (solid catalyst recovered after the first catalytic run), respectively, as indicated by STEM-HAADF (scanning transmission electron microscopy - high angle annular dark field) studies. 2'_TiO2 exhibits TOF values up to 23.7 min-1 in the oxidation of water to O2 driven by NaIO4 at nearly neutral pH, and a TON only limited by the amount of NaIO4 used, as indicated by multiple run experiments. Furthermore, while roughly 40¿% leaching is observed during the first catalytic run, 2'_TiO2 does not undergo any further leaching even when in contact with strongly basic solutions and completely maintains its activity for thousands of cycles. NMR studies, in combination with ICP-OES (inductively coupled plasma optical emission spectrometry), indicate that the activation of 2_TiO2 occurs through the initial oxidative dissociation of PO43-, ultimately leading to active centers in which a 1:1 P/Ir ratio is present (derived from the removal of two PO43- units) likely missing the Cp* ligand.Peer Reviewe

The bolsena-torre alfina geothermal field (Italy): a case of caldera-related blind geothermal resource

The Torre Alfina geothermal field is located about 10 km north of the Quaternary Bolsena caldera. The reservoir is a buried structural high made of Mesozoic-Cenozoic carbonatic sequences characterised by discontinuous secondary permeability and sealed by clay-rich alloctonous syn-orogenic flysch successions and Pliocene neo-authoctonous marine clays. The reservoir is locally highly productive, water-dominated and CO2-rich, with T at its top of 120 degrees C. The origin of the heat source was not investigated in detail but generally attributed to some unidentified deep magmatic body. Our field structural data document fracturing and faulting that affect both the reservoir and the seal units with dominant NE-SW and a subordinate E-W as maximum extension directions. The surface pattern and kinematics indicate that fault systems are part of the Pliocene-Quaternary tectonic episode in Central Italy, where strike-slip kinematics transfers deformation between main extensional shear zones. The fault network controls intense hydrothermal manifestations and travertine deposition north of the Torre Alfina area. 230Th/234U dating allows distinguishing three different stages of hydrothermal pulses bracketed between 200 and 90 ka. To improve the current understanding of the geometry and density of subsurface fracture system we applied the Shear Wave Splitting (SWS) technique studying the waveforms from local microearthquakes recorded in the area from 2008 to 2011. The analysis of SWS provides parameters directly related to the strike of the subsurface fluid-filled fractures and their density. According to the extensive-dilatancy anisotropy hypothesis (Crampin, 1984) SWS is generated by propagation through distributions of fluid-filled cracks, microcracks, and preferentially oriented pore space aligned according to the active stress field in the area. The analysis was made using the software ANISOMAT and gives a major direction NW-SE. The results agree both with structural data and with the focal mechanism of the earthquakes collected in the area between years 1977 and 1992. From the analysis on the crack density our data gives as result a good index of fracture for the reservoir’s rocks. Based on the updated conceptual model we performed numerical simulations in TOUGH2 code. Results indicate that deep circulation is forced by the geometry of the reservoir and by T and P gradients. We interpret the Torre Alfina field as a "blind" system, formed dominantly by lateral advection of heat and mass from the Bolsena caldera deep system driven both by high T and by the greater depth at which reservoir rocks are downthrown by the volcano-tectonic collapse. Preferential fracture fabric in the deep carbonates allows the lateral heat transfer. The cap-rocks have excellent sealing characteristics allowing the preservation of heat in correspondence with positive structural traps.PublishedKagoshima, Japan2T. Tettonica attiva5A. Energia e georisorse6A. Monitoraggio ambientale, sicurezza e territorioope

The bolsena-torre alfina geothermal field (Italy): a case of caldera-related blind geothermal resource

The Torre Alfina geothermal field is located about 10 km north of the Quaternary Bolsena caldera. The reservoir is a buried structural high made of Mesozoic-Cenozoic carbonatic sequences characterised by discontinuous secondary permeability and sealed by clay-rich alloctonous syn-orogenic flysch successions and Pliocene neo-authoctonous marine clays. The reservoir is locally highly productive, water-dominated and CO2-rich, with T at its top of 120 degrees C. The origin of the heat source was not investigated in detail but generally attributed to some unidentified deep magmatic body. Our field structural data document fracturing and faulting that affect both the reservoir and the seal units with dominant NE-SW and a subordinate E-W as maximum extension directions. The surface pattern and kinematics indicate that fault systems are part of the Pliocene-Quaternary tectonic episode in Central Italy, where strike-slip kinematics transfers deformation between main extensional shear zones. The fault network controls intense hydrothermal manifestations and travertine deposition north of the Torre Alfina area. 230Th/234U dating allows distinguishing three different stages of hydrothermal pulses bracketed between 200 and 90 ka. To improve the current understanding of the geometry and density of subsurface fracture system we applied the Shear Wave Splitting (SWS) technique studying the waveforms from local microearthquakes recorded in the area from 2008 to 2011. The analysis of SWS provides parameters directly related to the strike of the subsurface fluid-filled fractures and their density. According to the extensive-dilatancy anisotropy hypothesis (Crampin, 1984) SWS is generated by propagation through distributions of fluid-filled cracks, microcracks, and preferentially oriented pore space aligned according to the active stress field in the area. The analysis was made using the software ANISOMAT and gives a major direction NW-SE. The results agree both with structural data and with the focal mechanism of the earthquakes collected in the area between years 1977 and 1992. From the analysis on the crack density our data gives as result a good index of fracture for the reservoir’s rocks. Based on the updated conceptual model we performed numerical simulations in TOUGH2 code. Results indicate that deep circulation is forced by the geometry of the reservoir and by T and P gradients. We interpret the Torre Alfina field as a "blind" system, formed dominantly by lateral advection of heat and mass from the Bolsena caldera deep system driven both by high T and by the greater depth at which reservoir rocks are downthrown by the volcano-tectonic collapse. Preferential fracture fabric in the deep carbonates allows the lateral heat transfer. The cap-rocks have excellent sealing characteristics allowing the preservation of heat in correspondence with positive structural traps

Scarcity or Absence of Humoral Immune Responses in the Plasma and Cervicovaginal Lavage Fluids of Heavily HIV-1-Exposed But Persistently Seronegative Women

To address an existing controversy concerning the presence of HIV-1-specific antibodies of the IgA isotype in the female genital tract secretions of highly-exposed but persistently seronegative (HEPSN) women, 41 samples of plasma and cervicovaginal lavage (CVL) fluid were distributed to six laboratories for their blinded evaluation using ELISA with 10 different HIV-1 antigens, chemiluminescence-enhanced Western blots (ECL-WB), and virus neutralization. HIV-specific IgG or IgA antibodies in plasma samples from HEPSN women were absent or detectable only at low levels. In CVL, 11/41 samples displayed low levels of reactivity in ELISA against certain antigens. However, only one sample was positive in two of five laboratories. All but one CVL sample yielded negative results when analyzed by ECL-WB. Viral neutralizing activity was either absent or inconsistently detected in plasma and CVL. Plasma and CVL samples from 26 HIV-1-infected women were used as positive controls. Irrespective of the assays and antigens used, the results generated in all laboratories displayed remarkable concordance in the detection of HIV-1-specific antibodies of the IgG isotype. In contrast, IgA antibodies to HIV-1 antigens were not detected with consistency, and where present, IgA antibodies were at markedly lower levels than IgG. Although HIV-neutralizing activity was detected in plasma of all HIV-1-infected women, only a few of their CVL samples displayed such activity. In conclusion, frequent HIV-1 sexual exposure does not stimulate uniformly detectable mucosal or systemic HIV-1-specific responses, as convincingly documented in the present blindly performed study using a broad variety of immunological assays. Although HIV-1-infection leads to vigorous IgG responses in plasma and CVL, it does not stimulate sustained IgA responses in either fluid