UV-254 degradation of nicotine in natural waters and leachates produced from cigarette butts and heat-not-burn tobacco products.

Summarization: Nicotine is an important emerging contaminant widely detected in water resources. The main nicotine sources are human excretions from users and leaching from discarded tobacco product waste, which represents the most commonly littered item in urban areas and coasts. In this study, the UV254 photolytical fate of nicotine in natural water and leachates produced from conventional cigarettes (CCs) and the new generation heat-not-burn (HnBs) tobacco products is examined for the first time. The effect of UV254 irradiation on nicotine depletion in ultrapure water was initially studied. The reaction was pseudo first-order with respect to nicotine concentration at low concentrations and shifted to lower order at higher concentrations, an effect associated to absorption saturation. Although nicotine removal was fast, only 9.5% of the total organic carbon was removed after irradiation due to the formation of by-products. The chemical structures of six photo-products were derived by means of liquid and gas chromatography coupled to mass spectrometry. The photodegradation kinetics was found to depend on pH and faster kinetics were recorded when the monoprotonated form of nicotine was dominant (pH = 5–8). The presence of humic acids was found to slightly delay kinetics as they competed with nicotine for lamp irradiance, whereas the presence of salt had no effect on the direct photolysis of nicotine. Direct photolysis studies were also performed using natural waters. Compared to ultra-pure water, photodegradation was found to proceed slightly slower in river water, in similar kinetics in seawater, and relatively faster in rain water. The later was assumed to be due to the lower pH compared to the rest of the natural water tested. Leachates from used HnBs and smoked CCs were also submitted to UV254 irradiation and direct photolysis was found to proceed fast despite the high complexity of these matrices. Nonetheless, the total organic carbon in the system remained the same after irradiation due to the abundance of organics and photo-products formed. We take advantage of the present investigations and report the leaching behavior of nicotine from HnBs and CCs. Among others, we found that in HnBs ~70% of the total and bioavailable nicotine content remains in the tobacco sticks after operation and this percentage drops to 15% in CCs due to the reduction in mass after smoking. This finding demonstrated the importance of properly disposing tobacco product waste to prevent nicotine leaching in water bodies. Presented on: Environmental Researc

Reduction on characteristics for continuous solutions of a scalar balance law

We consider continuous solutions $u$ to the balance equation $$\partial_t u(t,x) + \partial_x [f(u(t,x))] = g(t,x) \quad f \in C^2(R), g \in L^\infty (R^+ \times R)$$ for a bounded source term $g$. Continuity improves to Holder continuity when $f$ is uniformly convex, but it is not more regular in general. We discuss the reduction to ODEs on characteristics, mainly based on the joint works [5, 1]. We provide here local Lipschitz regularity results holding in the region where $f'(u) f''(u) \ne 0$ and only in the simpler case of autonomous sources $g = g(x)$, but for solutions $u(t,x)$ which may depend on time. This corresponds to a local Lipschitz regularity result, in that region, for the system of ODEs \[ \begin{cases} {\dot\gamma(t) = f'(u(t,\gamma(t))) \\ \frac{d}{dt} u(t,\gamma(t)) = g(gamma(t)) \end{cases} \

A uniqueness result for the continuity equation in two dimensions

We consider certain properties of maps of class C 2 from Rd to Rd 121 that are strictly related to Sard\u2019s theorem, and show that some of them can be extended to Lipschitz maps, while others still require some additional regularity. We also give counterexamples showing that, in term of regularity, our results are optimal

Reduction on characteristics for continuous solutions of a scalar balance law

We consider continuous solutions u to the balance equation ∂t u(t, x) + ∂x [f (u(t, x))] = g(t, x) f ∈ C 2 (R), g ∈ L∞ (R) for a bounded source term g. Continuity improves to H ̈lder continuity o when f is uniformly convex, but it is not more regular in general. We discuss the reduction to ODEs on characteristics, mainly based on the joint works [5, 1]. We provide here local regularity results holding in the region where f (u)f (u) = 0 and only in the simpler case of autonomous sources g = g(x), but for solutions u(t, x) which may depend on time. This corresponds to a local regularity result, in that region, for the system of ODEs γ(t) = f (u(t, γ(t))) ̇ d u(t, γ(t)) = g(t, γ(t)). d

Synthesis, characterization, optimization and application of TiO2-based photocatalytic materials for environmental applications related to emerging pollution

This PhD thesis deals with the exploitation of heterogeneous photocatalysis, as an Advanced Oxidation Process, for environmental issues related to the emerging pollution: in particular for wastewater remediation and bacterial decontamination purposes. During this project, several photocatalytic materials have been synthesized by coupling semiconductor (TiO2) nanoparticles (both bare and doped) to different supporting materials, e.g. persistent luminescence materials (3ZnO:Ga2O3:2GeO2: Cr3+; CaAl2O4: (La, Nd)3+), magnetic and porous materials (ferrite nanoparticles, magnetic zeolite obtained from industrial waste) and polymeric materials (based on polydimethylsiloxane \u201cPDMS\u201d). In addition, an analytical approach to the study on the abatement and the quantification of emerging pollutants was considered, an important part of which was carried out at the Water Lab of the Environmental Engineering Department at Technical University of Crete, under the supervision of Professor Elia Psillakis. Specifically, TiO2 was synthesized through the sol-gel technique, both in the undoped and doped form (for example with Cu and N), while its crystallization on several supporting materials was obtained with different synthetic techniques such as: sol-gel synthesis, solid-state synthesis, hydrothermal/solvothermal synthesis and electrospinning technique. Some of the synthesized materials were investigated using a chemometric approach, that is the possibility to exploit an Experimental Design mathematical model in order to investigate the optimal synthetic conditions to get enhanced photocatalytic efficiency (within the experimental domain) for the materials. All samples synthesized within the current project were subjected to a physical-chemical characterization, by means of: X-Ray Diffraction \u201cXRD\u201d and crystallographic refinements (Rietveld, Pair Distribution Function \u201cPDF\u201d, Williamson-Hall plot), Scanning and Transmission Electron Microscopy-Energy Dispersive X-Ray Spectrometry \u201cSEM-EDS\u201d, \u201cTEM\u201d, Porosimetry Brunauer-Emmett-Teller \u201cBET\u201d, Dynamic Light Scattering \u201cDLS\u201d, Differential Scanning Calorimetry \u201cDSC\u201d, Diffuse Reflectance (Kubelka-Munk plots for Energy Gap \u201cEg\u201d), Rheological Measurements, Luminescence Properties, Turbidimetry, Inductively Coupled Plasma \u2013 Atomic Emission Spectroscopy \u201cICP-AES\u201d, Diffuse Reflectance Infrared Fourier Transform Spectroscopy \u201cDRIFTS\u201d and antibacterial properties with E. Coli cultures. Above all, a kinetic characterization in terms of photocatalytic efficiency evaluation was always performed for synthesized samples. In particular, kinetic behaviour of the photocatalysts was evaluated by means of Methylene Blue \u201cMB\u201d aqueous solutions degradation, studied as a function of time, with different initial concentrations (as required by ISO NORM 10678:2010). For MB quantification, a UV-Vis spectrophotometer was used, and experiments were usually performed in triplicate. Furthermore, during the first part of the project, a Pilot Plant Prototype was assembled (with a processing volume equal to 1L) and used for preliminary evaluations on a potential industrial scale-up. All tests and characterizations achieved were adapted according to the specific supporting material employed. Eventually, considering the nature of emerging micro-pollutants, an analytical approach to the determination of their concentration in aqueous systems was employed. Specifically, chromatographic tests were performed with liquid and gas chromatography techniques, often coupled with mass spectrometry, for some specific emerging pollutants (Ofloxacin, Parabens, Nicotine, Salbutamol). Matrix effects were also considered in the evaluation of the pollutants\u2019 degradation during the advanced oxidation tests. This task wouldn\u2019t have been possible without valuable National and International collaborations, which gave an essential help to the development of the project for what concerns a part of the reported characterization. My acknowledgements are directed to: Department of Chemistry and Industrial Chemistry - University of Genova (Analytical, Industrial, Physical Sections), Analytic and Photochemistry Section of the Department of Chemistry - University of Pavia; Department of Chemistry - University of Kuwait; Department of Environmental Engineering - Technical University of Crete; Institute of Methodologies of Environmental Analysis, Institute of Matter and Institute of Superconducting and other Innovative Materials and Devices - National Research Council. Each individual contribute will be highlighted in each dedicated section, throughout the manuscript

Criticità e confini della responsabilità precontrattuale

L'elaborato affronta due profili significativi della culpa in contrahendo. In primo luogo si occupa del dibattito sulla natura giuridica della stessa, prendendo posizione con argomenti tradizionali e nuovi a favore della sua natura extracontrattuale. In secondo luogo cerca di ragionare sulla collocazione codicistica e dogmatica della stessa, passando in rassegna alcune figure simili. Ciò permette nelle conclusioni di spostarsi dallo ius conditum allo ius condendum e immaginare qualche linea guida per risolvere con il formante legislativo alcuni problemi che resterebbero di competenza della sola dottrina e giurisprudenza

On the Euler-Lagrange equation for a variational problem: the general case II

In this paper we study the existence of a solution in Lloc() to the Euler\u2013Lagrange equation for the variational problem infu+W01()(ID(u)+g(u))dx(01) with D convex closed subset of Rn with non empty interior. By means of a disintegration theorem, we next show that the Euler\u2013Lagrange equation can be reduced to an ODE along characteristics, and we deduce that there exists a solution to Euler\u2013Lagrange different from 0 a.e. and satisfies a uniqueness property. These results prove a conjecture on the existence of variations on vector fields stated in Bertone and Cellina (On the existence of variations)

SBV regularity for Hamilton-Jacobi equations in Rn\mathbb R^n

In this paper we study the regularity of viscosity solutions to the following Hamilton-Jacobi equations $$\partial_t u + H(D_{x} u)=0 \qquad \textrm{in} \Omega\subset \mathbb R\times \mathbb R^{n} .$$ In particular, under the assumption that the Hamiltonian $H\in C^2(\mathbb R^n)$ is uniformly convex, we prove that $D_{x}u$ and $\partial_t u$ belong to the class $SBV_{loc}(\Omega)$.Comment: 15 page