1,724,190 research outputs found
Stato della SS. chiesa papale Lateranense nell'anno MDCCXXIII.
No full textSignatures: pi⁴ *⁴ A-Y⁴ Z⁶ [2A]1.Includes bibliographical references and index.Relazione delle nave principale della sacrosanta Chiesa Papale Lateranense / dell'abate Alessandro Baldeschi -- Ristretto delle cose più notabili, che oggi si veggono ne' portici, nelle navi minori, e traversa, e nella tribuna della sacrosanta Chiesa Papale Lateranense / di Gio. Mario Crescimbeni.Mode of access: Internet.Binding: old vellum over boards; gilt red leather label on spine
A statistical method to determine total H2O and CO2 budgets in magmas
No full textA recently developed method based on the TVLine concept (Papale, 2005) allows to determine total H2O and CO2 budgets in magmas from melt inclusion data. This method, however, can not be easily applied when multiple groups of inclusions are present in the dataset. This is unfortunately a frequent occurrence in many relevant cases, including recent eruptions of Etna, Stromboli, Campi Flegrei, Vesuvius, and
Kilauea volcanoes. We have developed a statistical method which allows to treat analytical uncertainties and group the data according to a probabilistic criterion. The method includes the following steps: i) hypothesize a number of pairs of total H2O and CO2 necessary to explain the observed data; ii) minimize a χ2-like quantity for each datum by varying the possible H2O-CO2 pairs, and using a model for compositional dependent multicomponent H2O+CO2 saturation in silicate melts (Papale et al., 2006). This step allows the assignment of each datum to a given total H2O-CO2 pair; iii) perform a Monte Carlo simulation to determine the probability of exceeding the obtained χ2, therefore the likelihood of the assumed number of total H2O-CO2 pairs to explain the database. This sequence is repeated for many possible numbers of H2O-CO2 pairs and many assumed values of analytical uncertainty characterizing the dataset. Application of the method to about 30 melt inclusion data from a recent Kilauea eruption spanning CO2 contents in the range 10-300 ppm shows that a minimum of two total H2O-CO2 pairs is required. These pairs show that the melt inclusions formed under two different conditions, the first one characterized by a few wt%, and the second one by less than 1 wt% CO2 abundance
A NEW METHOD TO COMPUTE FLUIDS SATURATION IN C-H-O-S-SILICATE MELT SYSTEMS
No full textWe developed a method to calculate equilibrium between a
C-O-H-S fluid phase and a silicate melt based on a previous
model for the saturation of H2O-CO2 fluids (Papale, 1999) and
on a thermochemical approach for calculating sulfide and
sulfate solubilities of simple and complex melts. In particular,
this second approach combines the Toop-Samis polymeric
model with the Flood - Grjotheim theoretical treatment of silicate
melts (Ottonello et al., 2001; Moretti, 2002). Moreover,
fugacities in the gaseous phase are computed through the
SUPERFLUID code (Belonoshko et al., 1992). The C-H-O-S
saturation model allows determining the partition of H2O, CO2,
and S between silicate melt and coexisting fluid, and the
composition of the fluid phase in terms of H2O, CO2, SO2, and
H2S, as a function of pressure, temperature, volatile-free liquid
composition, oxygen fugacity, and total amount of volatile
components in the system. For the sake of simplicity, we
assumed that no reduced or oxidized sulfur-saturated solid or
liquid phases nucleate or separate from the liquid-gas system.
Minima in sulfur solubility as a function of oxygen fugacity are
depicted, in good agreement with theory and experiments.
Applications are given for rhyolitic and basaltic melts with
various oxygen fugacities in the range NNO±2, and pressure
from a few hundred MPa to atmospheric. The developed model
accounts for the reciprocal effects of volatiles on their saturation
contents, and the complex relationships between the saturation
surface of a multicomponent fluid and the liquid
composition, volatile abundance, P-T conditions and oxidation
state.
Belonoshko A, Shi PF & Saxena S, Comp. Geosci, 18, 1267-
1269, (1992).
Moretti R, PhD Thesis, University of Pisa
Ottonello G, Moretti R, Marini L& Vetuschi Zuccolini M, Chem.
Geol, 174, 157-179, (2001).
Papale P, Amer. Mineral, 84, 477-492, (1999)
On the saturation surface and oxidation state of C-H-O-S-silicate melt systems
No full textThe equilibrium between a H2O–CO2–SO2–H2S gas phase
and silicate melts is investigated by means of thermochemical
calculations which join homogeneous reactions in the gas
phase and heterogeneous gas–melt saturation modeling based
on classical sub-regular multicomponent mixing and Toop-
Samis polymeric approach. Sulfur in the melt phase is
assumed to be present in two different oxidation states (sulfide
and sulfate ions). The thermodynamic model is an extension
of that presented in Moretti et al. [1] to account for iron
speciation at high pressure with variable dissolved water
contents. The consequences on the equilibrium conditions of
different assumptions on the effective redox buffer in magma
are examined for melts of basaltic and rhyolitic composition,
determining the equilibrium conditions on the basis of i)
constant FeII/FeIII, ii) constant fH2S/fSO2, and iii) constant
relative fO2, expressed as difference in log-units to a solid
buffer. The first two buffers are expected to be effective in
basaltic and andesitic-rhyolitic magmas, respectively,
according to the most abundant reservoir of redox couples.
Furthermore, for each assumed redox buffer the pressure
dependence of phase composition and oxidation state of the
system shows strongly non-linear trends. The largest
compositional differences are shown by sulfur species,
however, the concentrations of H2O and CO2 in the two
phases at equilibrium also show non-negligible dependence on
the redox conditions. For each assumed redox buffer, sulfur
dioxide in the gas phase, and sulfate ions in the liquid phase,
are found to be present in appreciable quantities or represent
the dominating sulfur species. The more reliable redox buffers
represented by constant FeII/FeIII for basalt, and constant
fH2S/fSO2 for rhyolite, show that oxygen fugacity paths
during magma depressurization strongly deviate from those
related to a solid buffer plus or minus a constant.
Results here presented, although not yet accounting for the
separation of S-bearing solid or liquid phases, may furnish
insights on the composition of gases separated from magmas
originated in various geodynamic settings, under different
redox conditions.
Reference
[1] Moretti R., Papale P. and Ottonello G. (2003) In: Volcanic
Degassing (Oppenheimer C., Pyle D. and Barclay J., eds.)
Geol. Soc. London Spec. Publ., 213, 81-101
Facemasks and Public Health: analysis of bacterial contamination in FFP2 masks: Gaia Papale
No full textBACKGROUND: Facemasks (FM), due to the Covid-19 pandemic, are extensively used and often worn beyond the recommended time. This has led to questions about the negative impact persistent contamination on FMs might have on public health. The study aims to assess the level of contamination reached in a small cohort of subjects after the recommended use (8 h) of FM. METHODS: This descriptive study was carried out between January and April 2022 on 17 people: 9 women and 8 men aged between 25-45 years. These two groups were divided into two micro-groups: women were selected according to their skincare habits (no skincare and skincare with cosmetics). In contrast, men were selected according to the length of their beards (thick or short beard). The FM was worn for 8 h in a controlled office setting, to avoid possible uncontrolled variables. Then, the FM was cut, placed in a tube with a recovery medium and centrifuged. The supernatant was removed and the pellet resuspended. Aliquots were plated on Petri plates and incubated for 48 h at 36 °C to count the Colony Forming Units (CFU). The statistical analysis was conducted using Stata software, performing the Wilcoxon matched-pairs and setting a significance level of p < 0.05. RESULTS: Women had higher FM contamination than men ([Image: see text] = 4960 vs 3130 CFU/ml). Also, we found more colonies ([Image: see text] = 18890 vs 3420 CFU/ml) in the FMs of women without skincare (p = 0.06), while among men, more colonies were reported for those with a thicker beard than for those with a shorter one ([Image: see text] = 3300 vs 2960 CFU/ml). CONCLUSIONS: Extensive FM use increases bacterial contamination exponentially. This could lead to changes in the facial microbiome, inducing skin conditions (such as allergic dermatitis and acne). Facial skin conditions are important public health issues for people wearing FMs daily. In addition, responsible handling of this equipment is essential to avoid the spread of SARS-CoV-2 through contact with these items, which can persist for many days. KEY MESSAGES: • Gender and physical characteristics may influence the level of contamination present on FFP2 face masks. • There is a need to increase community awareness on the proper handling of facemasks, prevent health problems for users, and limit the spread of infection to those around them
Précisions sur l'infaillibilité papale
No full textThils Gustave. Précisions sur l'infaillibilité papale. In: Revue théologique de Louvain, 1ᵉ année, fasc. 2, 1970. pp. 183-190
1198. La monarchia papale
No full textIl saggio segue le vicende della chiesa cattolica nel XII e nella prima metà del XIII secolo, con particolare riferimento all'affermazione del potere monarchico papale e alla lotta alle "eresie"
Montefiascone, la rocca papale
No full textIl saggio, corredato da alcune illustrazioni relative ad una tesi di diploma, dà conto di alcune nuove acquisizioni sull'impianto urbano del centro alto laziale e specialmente su alcuni suoi importanti monumenti come la chiesa di S.Andrea, il Castello, la Rocca papale.
In particolare le ricerche sul castello e sulla rocca papale hanno permesso di accertare la consistenza originaria del complesso, nonchè l'entità di alcune trasformazioni condotte fra il XV ed il XVI secolo poco note o completamente sconosciute. Tutte conoscenze queste che costituiscono il fulcro di ricerche che sono ancora in corso
A model for multicomponent fluid saturation in C-O-H-S-silicate melt systems
No full textThe dissolution behavior of volatile components in magmas is essential to model the
volcanic process from the deep regions of magma generation and storage to the shallow
regions of magma eruption and emplacement.
Water, carbon dioxide, and sulfur compounds are the main volatile components in natural
magmas, constituting in most cases more than 99% of the volcanic gases released
before, during, and after eruption.We have developed a method to calculate the chemical
equilibrium between a fluid phase in the C-O-H-S system and a silicate melt with
composition defined by ten major oxides. The method is based on a previous model
for the saturation of H2O-CO2 fluids [1] and on a sulfur solubility model [2] in silicate
liquids. For the computation of the fugacities of components in fluids with complex
composition we used the SUPERFLUID code [3]. The model allows determining the
partition of H2O, CO2, and S between the silicate liquid and the coexisting fluid, and
the composition of the fluid phase in terms of H2O, CO2, SO2, and H2S, as a function
of pressure, temperature, volatile-free liquid composition, oxygen fugacity, and
total amount of each volatile component in the system. App lications are presented
to several silicate liquids with rhyolitic and basaltic composition, oxygen fugacities
in the range NNO ± 2, and pressure from a few hundred MPa to atmospheric, with
the simplifying assumption that no reduced or oxidized sulfur-saturated solid or liquid
phases nucleate or separate from the liquid-gas system. Results show the well-known
minima in sulfur saturation contents as a function of oxygen fugacity, the reciprocal
effects of volatiles on their saturation contents, and the complex relationships between
saturation surface of a multicomponent fluid, liquid composition, volatile abundance,
P-T conditions, and oxidation state. The method represents therefore a new powerful
tool for the prediction of multicomponent gas-melt equilibria in magmas.
REFERENCES
[1] Papale P. (1999) Am. Mineral., 84, 477-492
[2] Moretti R. and Ottonello G. This issue
[3] Belonoshko A.B., Shi P. and Saxena S,K, (1992) Comp. Geosci., 18, 1267-1269.
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