DETERMINATION OF THERMAL RESPONSE OF CARRARA AND SNEZNIKOVSKY MARBLE USED AS A BUILDING MATERIALS

Physical weathering of marble, widely used as a cladding material on buildings, is one of the most common damaging mechanism caused by anisotropic thermal expansion of calcite grains. The extent of marble deterioration depends mainly on stone fabric and texture. Dry cuboids of Carrara marble and marble from Dolni Morava quarry were subjected to microscopic analysis and thermal cycling, to determine the thermal expansion related to stone fabric and predominant lattice orientation of grains (i.e. texture)

Cost free hyper-parameter selection/averaging for Bayesian inverse problems with vanilla and Rao-Blackwellized SMC samplers

In Bayesian inverse problems, one aims at characterizing the posterior distribution of a set of unknowns, given indirect measurements. For non-linear/non-Gaussian problems, analytic solutions are seldom available: Sequential Monte Carlo samplers offer a powerful tool for approximating complex posteriors, by constructing an auxiliary sequence of densities that smoothly reaches the posterior. Often the posterior depends on a scalar hyper-parameter, for which limited prior information is available. In this work, we show that properly designed Sequential Monte Carlo (SMC) samplers naturally provide an approximation of the marginal likelihood associated with this hyper-parameter for free, i.e. at a negligible additional computational cost. The proposed method proceeds by constructing the auxiliary sequence of distributions in such a way that each of them can be interpreted as a posterior distribution corresponding to a different value of the hyper-parameter. This can be exploited to perform selection of the hyper-parameter in Empirical Bayes (EB) approaches, as well as averaging across values of the hyper-parameter according to some hyper-prior distribution in Fully Bayesian (FB) approaches. For FB approaches, the proposed method has the further benefit of allowing prior sensitivity analysis at a negligible computational cost. In addition, the proposed method exploits particles at all the (relevant) iterations, thus alleviating one of the known limitations of SMC samplers, i.e. the fact that all samples at intermediate iterations are typically discarded. We show numerical results for two distinct cases where the hyper-parameter affects only the likelihood: a toy example, where an SMC sampler is used to approximate the full posterior distribution; and a brain imaging example, where a Rao-Blackwellized SMC sampler is used to approximate the posterior distribution of a subset of parameters in a conditionally linear Gaussian model

Microstructural characterization of dental zinc phosphate cements using combined small angle neutron scattering and microfocus X-ray computed tomography.

Abstract Objective To characterize the microstructure of two zinc phosphate cement formulations in order to investigate the role of liquid/solid ratio and composition of powder component, on the developed porosity and, consequently, on compressive strength. Methods X-ray powder diffraction with the Rietveld method was used to study the phase composition of zinc oxide powder and cements. Powder component and cement microstructure were investigated with scanning electron microscopy. Small angle neutron scattering (SANS) and microfocus X-ray computed tomography (XmCT) were together employed to characterize porosity and microstructure of dental cements. Compressive strength tests were performed to evaluate their mechanical performance. Results The beneficial effects obtained by the addition of Al, Mg and B to modulate powder reactivity were mitigated by the crystallization of a Zn aluminate phase not involved in the cement setting reaction. Both cements showed spherical pores with a bimodal distribution at the micro/nano-scale. Pores, containing a low density gel-like phase, developed through segregation of liquid during setting. Increasing liquid/solid ratio from 0.378 to 0.571, increased both SANS and XmCT-derived specific surface area (by 56% and 22%, respectively), porosity (XmCT-derived porosity increased from 3.8% to 5.2%), the relative fraction of large pores ≥50 μm, decreased compressive strength from 50 ± 3 MPa to 39 ± 3 MPa, and favored microstructural and compositional inhomogeneities. Significance Explain aspects of powder design affecting the setting reaction and, in turn, cement performance, to help in optimizing cement formulation. The mechanism behind development of porosity and specific surface area explains mechanical performance, and processes such as erosion and fluoride release/uptake

Evolution of calcite surfaces upon thermal decomposition, characterized by electrokinetics, in-situ XRD, and SEM

The present study analyses transformation pathways of pristine and thermally treated porous limestone and dense marble surfaces by means of time-resolved streaming current and potential measurements coupled with scanning electron microscopy and in-situ X-ray diffraction. The results reveal that under nonequilibrium conditions the zeta potential (ζ) of natural carbonates may exhibit positive and negative signs and ζ drifts in opposite directions. Sample surface roughness influences ζ because it contributes to dissolution, as observed particularly in the initial period of time-resolved measurements. Thermal treatment causes a temporary charge reversal from negative to positive. The reactivity of calcium hydroxide on calcite surfaces governs the net electrokinetic potential and isoelectric point (IEPpH), even at low surface coverage, as cross-validated by in-situ XRD. It was also found that pore conductivity may lead to ~90% underestimation of ζ when assessed by streaming potential. SEM studies revealed micro cracks inducement on marble after thermal treatment, which can result in underestimation of ζ up to the same extent as for the porous limestone. When an asymmetric cell configuration involving calcite and polypropylene surfaces is used, the fractional contribution of polypropylene to the IEPpH is 0.3 and to the overall determined ζ up to 0.5. Our findings contribute to the understanding of nonequilibrium and time-dependent electrokinetic potential modifications associated with the reactivity of porous surfaces. This study highlights the effectiveness of the streaming potential technique for monitoring such changes further supported by the use of ancillary techniques to analyze the extend of chemo-mineralogical and physical alterations

Angular and Current-Target Correlations in Deep Inelastic Scattering at HERA

Correlations between charged particles in deep inelastic ep scattering have been studied in the Breit frame with the ZEUS detector at HERA using an integrated luminosity of 6.4 pb-1. Short-range correlations are analysed in terms of the angular separation between current-region particles within a cone centred around the virtual photon axis. Long-range correlations between the current and target regions have also been measured. The data support predictions for the scaling behaviour of the angular correlations at high Q2 and for anti-correlations between the current and target regions over a large range in Q2 and in the Bjorken scaling variable x. Analytic QCD calculations and Monte Carlo models correctly describe the trends of the data at high Q2, but show quantitative discrepancies. The data show differences between the correlations in deep inelastic scattering and e+e- annihilation.Comment: 26 pages including 10 figures (submitted to Eur. J. Phys. C

Luigi Settembrini. Periodico letterario educativo mensile. A. 2, n.1(1892)-A. 3, n.10(1894)

A.2, n.1(nov.1892): G. Olivieri, Ad Antonio Bartolini, P. 1-2 ; G. Olivieri, Prospero Viani, P. 2-11; R. Sabbatini, Ancora Quom o Quum?, P. 11-2 ; Pensieri del Settembrini, P. 12-3 ; E. Perito, Ad nubem, P. 13; F. Lagrance, Dell’educazione fisica, p. 14-15 ; Cronaca dell’Istituto L. Settembrini, P. 15-6.A. 2, n. 2(dic. 1892): G. Lanzalone, La morale nell’arte, P. 17-23 ; B. ( dal Bibliografo), Per i libri di testo nelle scuole elementari, P. 23-5 ; V. Notari, In Gutembergium artis typograficae inventorem, P. 25; Progressi della navigazione aerea, P. 26-8 ; Pensieri del Settembrini, P. 28-9 ; Il nostro concorso, P. 29 ; G. Lanzalone, La prima pioggia d’autunno, P. 30-1A. 2, n.3(gen. 1893): Bonghi, Una lettera del Bonghi, P. 33-4 ; G. Lanzalone, Ancora della morale nell’arte, P. 34-8 ; Pensieri del Settembrini, P. 38-9 ; C. Arlìa, Buon dì e tre anguille, P. 39-41 ; G. Lanzalone , All’amico G. Olivieri , P. 42-3 ; P. Lioy, Bagni e villeggiature, P. 43-5.A. 2, n. 4(feb. 1893): C. A. Alemagna, Per la morale nell’arte, P. 49-55.A. 2, n. 5(mar. 1893): R. Sabbatini, L’epistola di Saffo a Faone, P. 65-6 ; G. Lanzalone, Il drammaturgo(caricatura), P. 66-7 ; G. Lanzalone, Ancora per la morale dell’arte, P. 67-70 ; F. De Falco, Un’altra lettera!, P. 71-2 ; Il Settembrini, Per una petizione al Parlamento, P. 72; E. Perito, A mia sorella morta, P. 73-4.A. 2, n.6(apr. 1893): Il Settembrini, Petizione al Parlamento, P. 81-3 ; C. Arlia, Noterelle filologiche, P. 84-5 ; G. Bigoni, Ricordi Picentini (2 sonetti), P. 85 ; C. A. Alemagna, Lettera con annotazioni, P. 86-90 ; V. Caputo, Il giuramento, P. 90-1 ; A. Buscaino Campo, Il piè fermo di Dante, P. 92-3.A.2, n.7(apr. 1893): G. Lanzalone, Professori e maestri, P. 97-9 ; il Settembrini, Petizione al Parlamento, P. 100-2 ; Lista delle adesioni, P. 102-4 ; Guido Bigoni, Domenica Rusticana, P. 105 ; Pensieri del Settembrini, P. 105-7 ; Dal Gazzettino d’oro, Utili varietà, P. 107-8 ; G. Lanzalone, Al maggiore Vincenzo Notari, P. 108 ; V. Notarius, Risposta, P. 109 ; F. Accinelli, La poesia della vita, P. 109-10.A. 2, n.8(giu. 1893): C. Arlìa, Noterelle filologiche, P. 113-16 ; Guido Bigoni, La quercia del Tasso, P. 116 ; G. Lanzalone, La ginnastica con la neve, P. 116-17 ; Luigi Settembrini, Una lettera inedita di L. Settembrini, P. 118-19 ; V. Notaro, In Ariostum, P. 119 ; L’arte di respirare, P. 120-21 ; F. De Falco, Il suicidio e la religione, P. 122-24.A.2, n.9/10(lug.-ago. 1893): R. Mariano, Ad un banchetto nunziale, P. 129-132 ; G. Lanzalone, A Cristoforo Colombo, P. 132-34 ; C. Arlìa, Note filologiche, P. 135-36 ; G. Olivieri, Il terzo libro della vita di G. Cristo, P. 136-39 ; F. Persico, La pace, P. 140-41 ; L. A. Villari, Cesare Dalbono, P. 141-45.A.2, n.11/12(sett.-ott. 1893): Luigi Settembrini, Una lettera inedita di L. Settembrini, P. 153-54 ; A. De Leo, Vite di illustri salernitani, P. 154-62 ; G. Franciosi, I sogni, P. 162-63 ; A. Frabasile, Bozzetti ellenici, P. 164-70 ; L. A. Villari , Errori Giudiziari, P. 171-75 ; G. Lanzalone, Verismo, P. 175-76.A.3,n.1/2 (nov.-dic. 1893): M. Giordano, La pubblica educazione e l’ateismo, P. 1-4 ; il Settembrini, Concorso, P. 4 ; Per una forca conservata in un museo, P. 5 ; G. Lanzalone, L’Ora presente, P. 5 ; C. Mariano Pilar, Silvio Spaventa, P. 6-19 ; C. Arlìa, Note filologiche, P. 20-1 ; G. Grammatica, Ideale, P. 22 ; G. Olivieri, Funesta rimembranza, P. 31-2 ; G. Olivieri, La notte della vigilia del Natale, P. 32.A.3, n.3/4(gen.-feb. 1894): G. Lanzalone, E la nostra petizione?, P. 33-5 ; Dall’albo di Luigi Antonio Villari, P. 36 ; G. Olivieri, Una visita inaspettata, P. 37-46 ; A. Frabasile, Alla signora G. P., P. 47 ; M. Giordano, Il Governo, i Municipi e l’istruzione religiosa, P. 48-53 ; G. Lanzalone, Esercizi militari, P. 53 ; C. Arlìa, Note filologiche, P. 54 ; G. Lanzalone, Un dubbio proposto al prof. Sabbadini, P. 54-5 ; G. L., Risultato del passato concorso e concorso nuovo, P. 55-6 ; R. Galdi, Epistola di Catullo ad Ortalo, P. 57.A.3, n.5/6(mar-apr 1894): G. Lanzalone, Dell’educazione nelle scuole classiche, P. 65-70 ; G. L., Un epigramma di Leone XIII, P. 70-1 ; V. Caputo, Vita di borso, P. 72-6 ; C. Arlìa, Note filologiche, P. 76-7 ; G. Lanzalone, Amore, P. 78 ; Aniello Gaeta, Dulcissime Rerum, P. 79-81 ; Francesco De Falco, La duchessa Ravaschieri e il dormitorio, P. 81-2 ; Carmine Zottoli, Risultato del passato concorso e concorso nuovo, P. 82-6.A.3, n. 7/8(mag. – giu 1894): C. Arlìa, Note filologiche, P. 97-8 ; G. Lanzalone, Per il 1°Maggio, P. 98-101 ; M. Giordano, La libertà d’insegnamento e di coscienza, P. 101-10 ; L. A. Villari, Il capitano Tim- Tim, P. 111- 15 ; C. A. Alemagna, L’opera recente di Herbert Spencer, P. 115-16 ; Nicc. Castagna, Sospiro, P. 116 ; G. Cuomo, Sovra un passo del carme “I Sepolcri”, P. 117-20.A.3, n.9(lug. 1894): Concorso nuovo, P. 125 ; C. Arlìa, Note filologiche, P. 126-27 ; Il manicomio dei genii, P. 127 ; G. Lanzalone, Elena, P. 128 ; Giovanni Cuomo, Nunzio del giorno, P. 128-29 ; Giovanni Manfredi, Ofelia, P. 129 ; G. Lanzalone, Da Anacreonte, P. 139.A.3, n.10(ago. 1894): R. Sabbadini, L’anno della nascita di Gasparino Barziza, P. 141-42 ; G. Lanzalone, Il Discredito dei versi, P. 142-46 ; C. Arlìa, Note filologiche, P. 147-48 ; E. Perito, L’ultima rosa d’estate, P. 148 ; D’Aloja, L’arte e la critica, P. 149-51 ; Epigrammi, P. 151-52