Precipitation of barium sulphate from aqueous solutions was investigated in a tubular reactor. Crystal size distribution and morphology were measured at the reactor outlet. Experimental data were ...compared with model predictions using CFD coupled with a micromixing model. Some anti-symmetric effects of ion excess on precipitation were observed. Activity coefficients were used in modelling precipitation, but even if thermodynamic properties of the solutions plays a role in determining nucleation and growth rates, this approach alone is not sufficient to give satisfactory agreement.
The conversion of 2-chloropropane (2-CP) in the presence of oxygen has been investigated over a number of catalysts including alumina and alumina-supported copper chloride, manganese tungstate, mixed ...manganese−aluminum oxide, silica−alumina, and ZSM5 zeolite. Dehydrochlorination to propene + HCl is predominant, but other reactions such as oxychlorination to deeper chlorided compounds, cracking, oligomerization, and aromatization can occur. On silica−alumina, a selectivity to propene approaching 100% is found and very high conversion can be obtained above 400 K. Over this catalyst the reaction kinetics is found to be zero order in 2-CP with an activation energy near 14.5 kcal/mol. 2-CP converts definitely faster than 1-chloropropane. FT-IR spectroscopy shows that the molecular adsorption of 2-CP is fast and reversible at low temperature, while a nucleophilic substitution occurs to give strongly adsorbed 2-propoxide species starting from near 373 K. The elimination reaction of 2-propoxide to gas-phase propene occurs slowly just near 400 K. The desorption of HCl is also observed to be quite fast in this low-temperature range. FT-IR and kinetic data suggest that the rate-determining step is associated with the elimination reaction from 2-propoxides to propene occurring via an E1-type mechanism through a secondary carbenium ion.
The dynamics of a microbial population isolated from superficial waters of Venice Lagoon and the ability to utilise diesel fuel (n-alkanes mixture C12-C28) as the sole carbon and energy source were ...studied in a long-term reconstruction experiment. The reconstructed microbial population consisted of three bacterial strains belonging to the species Acinetobacter venetianus, Pseudomonas putida, and Alcaligenes faecalis, which were able to oxidise n-alkanes to alkanoates, n-alkanols to alkanoates, or only n-alkanoates, respectively. Three different approaches: plate counting, cell counting by epifluorescence microscopy with DAPI staining, and by fluorescence in situ hybridisation (FISH) by using a probe conjugate with fluoresceine isothiocyanate specifically targeted towards the 16S rRNA of bacteria belonging to the genus Acinetobacter were used to monitor the growth of the bacterial population. The growth of A. venetianus was stimulated by the presence of other strains, suggesting a beneficial interaction. After the first week of growth A. venetianus cells formed aggregates, as confirmed by confocal microscopy (CLSM), which allowed them to be distinguished from free cells. A relationship between cell number and measured areas (microm2) per aggregate was found. Each cell presented an average surface of 1.21 microm2. Each aggregate was formed by a cellular monolayer biofilm consisting of up to several thousands of cells. The A. venetianus aggregates increased in number and size over time, but after two weeks fragmentation events, which had a beneficial effect on the growth of P. putida and A. faecalis, occurred.
Primordial non-Gaussianity (PNG) is one of the most powerful probes of the early Universe and measurements of the large scale structure of the Universe have the potential to transform our ...understanding of this area. However relating measurements of the late time Universe to the primordial perturbations is challenging due to the non-linear processes that govern the evolution of the Universe. To help address this issue we release a large suite of N-body simulations containing four types of PNG: \textsc{quijote-png}. These simulations were designed to augment the \textsc{quijote} suite of simulations that explored the impact of various cosmological parameters on large scale structure observables. Using these simulations we investigate how much information on PNG can be extracted by extending power spectrum and bispectrum measurements beyond the perturbative regime at \(z=0.0\). This is the first joint analysis of the PNG and cosmological information content accessible with power spectrum and bispectrum measurements of the non-linear scales. We find that the constraining power improves significantly up to \(k_\mathrm{max}\approx 0.3 h/{\rm Mpc}\), with diminishing returns beyond as the statistical probes signal-to-noise ratios saturate. This saturation emphasizes the importance of accurately modelling all the contributions to the covariance matrix. Further we find that combining the two probes is a powerful method of breaking the degeneracies with the \(\Lambda\)CDM parameters.
We study primordial non-Gaussian signatures in the redshift-space halo field on non-linear scales, using a quasi-maximum likelihood estimator based on optimally compressed power spectrum and modal ...bispectrum statistics. We train and validate the estimator on a suite of halo catalogues constructed from the Quijote-PNG N-body simulations, which we release to accompany this paper. We verify its unbiasedness and near optimality, for the three main types of primordial non-Gaussianity (PNG): local, equilateral, and orthogonal. We compare the modal bispectrum expansion with a \(k\)-binning approach, showing that the former allows for faster convergence of numerical derivatives in the computation of the score-function, thus leading to better final constraints. We find, in agreement with previous studies, that the local PNG signal in the halo-field is dominated by the scale-dependent bias signature on large scales and saturates at \(k \sim 0.2~h\,\mathrm{Mpc}^{-1}\), whereas the small-scale bispectrum is the main source of information for equilateral and orthogonal PNG. Combining power spectrum and bispectrum on non-linear scales plays an important role in breaking degeneracies between cosmological and PNG parameters; such degeneracies remain however strong for equilateral PNG. We forecast that PNG parameters can be constrained with \(\Delta f_\mathrm{NL}^\mathrm{local} = 45\), \(\Delta f_\mathrm{NL}^\mathrm{equil} = 570\), \(\Delta f_\mathrm{NL}^\mathrm{ortho} = 110\), on a cubic volume of \(1 \left({ {\rm Gpc}/{ {\rm h}}} \right)^3\), at \(z = 1\), considering scales up to \(k_\mathrm{max} = 0.5~h\,\mathrm{Mpc}^{-1}\).
The development of nonmyeloablative conditionings has recently reduced the transplant-related mortality (TRM) and extended the eligible age for transplantation up to 65–70 years. From January 2000 to ...June 2005, 106 newly diagnosed patients younger than 65 years were enrolled in a prospective phase II study at 15 Italian Centers. Fifty-eight were also previously described in a comparison of autografting with allografting based on a genetic randomisation (Bruno et al. N Engl J Med 2007). Here we report on a larger GITMO experience with a longer follow-up. Induction chemotherapy consisted of VAD-based regimens, followed by a cytoreductive autograft with melphalan 200 mg/m2, and by a non-myeloablative 2 Gy TBI-based allograft from an HLA-identical sibling. Graft-vs-host disease (GVHD) prophylaxis included cyclosporin and mycophenolate mofetil. Primary endpoints were overall (OS) and event-free (EFS) survivals. Secondary endpoint was TRM. One-hundred-two (96%) patients, median age 54 (30–65), completed the tandem program whereas 4 withdrew their consent. After a median follow-up of 54 (21–94) months, OS was not reached and median EFS was 35 (31–56) months post-transplant. Incidences of acute grade II-IV GHVD and extensive chronic GVHD were 40% and 50% respectively. Fourteen (13%) patients died from TRM, 14 (13%) from disease progression, 2 from lung cancer (2%) and 1 from lymphoma (1%). Overall response, defined as complete (CR) and partial remission, was 91% (93/102), with 53 patients achieving CR. Overall 39/102 patients relapsed, however only 8/53 of those who reached CR post-transplant. By multivariate-analysis disease response prior to allografting was significantly associated with longer OS (HR 0.27, CI 0.09–0.80, p<0.018) and longer EFS (HR 0.23, CI 0.11–0.49, p<0.001). Interestingly, chronic GVHD was not correlated with either the achievement of post-transplant CR (HR 0.87, CI 0.45–1.65, p<0.66) or its duration (HR 0.79, CI 0.45–1.40, p<0.42). Presence of del(13) was evaluated only in a subset of 39 patients: 13 carried del(13) and 26 did not. OS was not reached in the patients without del(13) and was 52 months in patients with del(13) (p=0.32), however EFS was not reached in the patients without del(13) whereas was 27 months for patients with del(13) (p=0.04). Given the encouraging results, the design of prospective studies that incorporate new drugs to cytoreduce the disease pre-transplant and enhance graft-vs.-myeloma are warranted to lower relapse rates and improve clinical outcomes.
We investigate how much can be learnt about four types of primordial non-Gaussianity (PNG) from small-scale measurements of the halo field. Using the QUIJOTE-PNG simulations, we quantify the ...information content accessible with measurements of the halo power spectrum monopole and quadrupole, the matter power spectrum, the halo-matter cross spectrum and the halo bispectrum monopole. This analysis is the first to include small, non-linear scales, up to \(k_\mathrm{max}=0.5 \mathrm{h/Mpc}\), and to explore whether these scales can break degeneracies with cosmological and nuisance parameters making use of thousands of N-body simulations. We perform all the halo measurements in redshift space with a single sample comprised of all halos with mass \(>3.2 \times 10^{13}~h^{-1}M_\odot\). For local PNG, measurements of the scale dependent bias effect from the power spectrum using sample variance cancellation provide significantly tighter constraints than measurements of the halo bispectrum. In this case measurements of the small scales add minimal additional constraining power. In contrast, the information on equilateral and orthogonal PNG is primarily accessible through the bispectrum. For these shapes, small scale measurements increase the constraining power of the halo bispectrum by up to \(\times4\), though the addition of scales beyond \(k\approx 0.3 \mathrm{h/Mpc}\) improves constraints largely through reducing degeneracies between PNG and the other parameters. These degeneracies are even more powerfully mitigated through combining power spectrum and bispectrum measurements. However even with combined measurements and small scale information, equilateral non-Gaussianity remains highly degenerate with \(\sigma_8\) and our bias model.
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