Semilinear nonautonomous parabolic equations with unbounded coefficients in the linear part

We study the Cauchy problem for the semilinear nonautonomous parabolic equation $u_t=\mathcal{A}(t)u+\psi(t,u)$ in $[s,\tau]\times {{\mathbb R}^d}$, $\tau> s$, in the spaces $C_b([s, \tau]\times{{\mathbb R}^d})$ and in $L^p((s, \tau)\times{{\mathbb R}^d}, \nu)$. Here $\nu$ is a Borel measure defined via a tight evolution system of measures for the evolution operator $G(t,s)$ associated to the family of time depending second order uniformly elliptic operators $\mathcal{A}(t)$. Sufficient conditions for existence in the large and stability of the null solution are also given in both $C_b$ and $L^p$ contexts. The novelty with respect to the literature is that the coefficients of the operators $\mathcal{A}(t)$ are allowed to be unbounded

Hypercontractivity and Asymptotic Behavior in Nonautonomous Kolmogorov Equations

We consider a class of nonautonomous second order parabolic equations with unbounded coefficients defined in I × ℝ d , where I is a right-halfline. We prove logarithmic Sobolev and Poincaré inequalities with respect to an associated evolution system of measures {μ(t) : t ∈ I}, and we deduce hypercontractivity and asymptotic behavior results for the evolution operator G(t, s)

Functionalized Mesoporous Silica is a viable alternative to bentonite for wine protein stabilization

The presence of grape-derived heat unstable proteins can lead to haze formation in white wines [1], an instability prevented by removing these proteins by adding bentonite, a hydrated aluminum silicate that interacts electrostatically with wine proteins leading to their flocculation. Despite effective, using bentonite has several drawbacks as the costs associated with its use, the potential negative effects on wine quality, and its environmental impact, so that alternative solutions are needed. This project aimed at evaluating the effectiveness of functionalized mesoporous silica (FMS), in removing heat unstable proteins from white musts and wines. FMS treatments were benchmarked against a commercial Na-Bentonite in a series of experiments conducted on heat unstable white musts and wines of different origin, vintage and variety, and on different scales (from few mL to 10 hL). The stabilizing properties of the fining agents were determined by analyzing the protein profiles of treated wines (by RP-HPLC), and by assessing protein stability via heat tests [3]. In addition, the treatments’ impact on other wine parameters (e.g., organic acid profiles, metal content, macromolecules, lees formation, sensory analysis) were determined. For each wine, the dose of bentonite and FMS needed to reach full protein stability was determined by fining rate trials. The amount of FMS needed to stabilize the wines was always in line with that of bentonite, with a small variability (±10%) attributable to differences in wine composition. FMS effectively removed both thaumatin-like proteins and chitinases in a dose dependent mode, without causing other modifications on wine composition in terms of organic acid profile, ethanol content, glycerol, volatile composition, and metal content that, on the other hand, was always modified by bentonite fining that always led to an increase in Fe and Al. The analysis by triangle test of two white wines (Sauvignon blanc and Traminer) stabilized with FMS or bentonite at similar addition rates revealed the lack of significant differences (total answers = 39, p = 0. 5599 for S. blanc, p = 0.1184 for Traminer). In general, FMS showed to effectively stabilized wines at addition rates similar to those of bentonite, without causing major compositional modification, nor detectable sensory impacts, and therefore they represent a good candidate to become a viable bentonite alternative. References (max 5) 1. Van Sluyter, S.C.; McRae, J.M.; Falconer, R.J.; Smith, P.A.; Bacic, A.; Waters, E.J.; Marangon, M. Wine Protein Haze: Mechanisms of Formation and Advances in Prevention. J. Agric. Food Chem. 2015, 63, 4020–4030, doi:10.1021/acs.jafc.5b00047. 2. Lambri, M.; Dordoni, R.; Silva, A.; Faveri, D.M.D. Effect of Bentonite Fining on Odor-Active Compounds in Two Different White Wine Styles. Am. J. Enol. Vitic. 2010, 61:2, 225–233. 3. McRae, J.M.; Barricklow, V.; Pocock, K.F.; Smith, P.A. Predicting Protein Haze Formation in White Wines. Aust. J. Grape Wine Res. 2018, 24, 504–511, doi:10.1111/ajgw.12354

Indicatori ambientali nello studio EpiAir2: I dati di qualit\ue0 dell'aria per la sorveglianza epidemiologica

OBIETTIVO: costruzione di indicatori ambientali di inquinamento aerodiffuso per finalit\ue0 di sorveglianza epidemiologica in 25 citt\ue0 italiane per il progetto EpiAir2 (2006-2010) e presentazione dei dati di dieci anni di sorveglianza in 10 citt\ue0 italiane (2001-2010). DISEGNO: sono stati raccolti dati di particolato (nelle frazioni PM10 e PM2.5 ), biossido di azoto (NO2 ) e ozono (O3 ), considerati fattori di rischio per la salute. I datimeteorologici considerati come confondenti nell\u2019analisi dell\u2019effetto degli inquinanti sono stati: temperatura, umidit\ue0 relativa (e la variabile derivata \u201ctemperatura apparente\u201d) e pressione barometrica. I criteri per la selezione delle stazioni dimonitoraggio e imetodi di calcolo per la costruzione di indicatori ambientali a partire dalle serie giornaliere disponibili sono stati scelti in continuit\ue0 con la precedente edizione di EpiAir. Per tutte le citt\ue0, \ue8 stata verificata l\u2019omogeneit\ue0 dei dati selezionati nel rappresentare l\u2019esposizione delle popolazioni. SETTING E PARTECIPANTI: il progetto EpiAir2 coinvolge per gli anni 2006-2010 le citt\ue0 diMilano,Mestre-Venezia,Torino, Bologna, Firenze, Pisa, Roma,Taranto,Cagliari e Palermo, gi\ue0 presenti nello studio EpiAir. A questo elenco vanno aggiunte le citt\ue0 di Treviso, Trieste, Padova, Rovigo, Piacenza, Parma, Ferrara, Reggio Emilia, Modena, Genova, Rimini, Ancona, Bari, Napoli e Brindisi. RISULTATI: nel periodo considerato \ue8 stato osservato un decremento delle concentrazioni di particolato nella maggior parte delle citt\ue0 in analisi, mentre non si pu\uf2 giungere a conclusioni cos\uec nette per NO2 e ozono. L\u2019analisi dell\u2019andamento temporale degli indicatori ha evidenziato valori medi annuali di PM10 superiori ai 40 \u3bcg/m3 in alcune citt\ue0 della Pianura Padana, e valori medi annuali di NO2 costantemente superiori ai 40 \u3bcg/m3 nelle citt\ue0 di Trieste, Milano, Padova, Torino, Modena, Bologna, Roma e Napoli. CONCLUSIONE: l\u2019ampliamento del progetto EpiAir, con l\u2019inclusione di ulteriori 13 citt\ue0, ha permesso di evidenziare peculiarit\ue0 legate alle differenti aree geografiche in studio e numerose situazioni di criticit\ue0 con superamenti dei valori di concentrazione limite fissati dalla legislazione corrente. I risultati dello studio EpiAir2 confermano la necessit\ue0 di un sistema di sorveglianza dell\u2019inquinamento aerodiffuso nei centri urbani e industriali al fine di ottenere stime affidabili dell\u2019esposizione della popolazione residente e di monitorarne l\u2019andamento nel tempo