Bifurcations in dissipative fermionic dynamics

The Boltzmann-Langevin One-Body model (BLOB), is a novel one-body transport approach, based on the solution of the Boltzmann-Langevin equation in three dimensions; it is used to handle large-amplitude phase-space fluctuations and has a broad applicability for dissipative fermionic dynamics. We study the occurrence of bifurcations in the dynamical trajectories describing heavy-ion collisions at Fermi energies. The model, applied to dilute systems formed in such collisions, reveals to be closer to the observation than previous attempts to include a Langevin term in Boltzmann theories. The onset of bifurcations and bimodal behaviour in dynamical trajectories, determines the fragment-formation mechanism. In particular, in the proximity of a threshold, fluctuations between two energetically favourable mechanisms stand out, so that when evolving from the same entrance channel, a variety of exit channels is accessible. This description gives quantitative indications about two threshold situations which characterise heavy-ion collisions at Fermi energies. First, the fusion-to-multifragmentation threshold in central collisions, where the system either reverts to a compact shape, or splits into several pieces of similar sizes. Second, the transition from binary mechanisms to neck fragmentation (in general, ternary channels), in peripheral collisions.Comment: Conf. proc. ECHIC November 6-8, 2013 Messina (Italy

La nuova Intesa con la Regione Ecclesiastica Sicilia sui beni culturali ecclesiastici alla luce del sistema concordatario italiano: l’atipicità diventa “tipica”?

The main topic analysed in the essay is the outline of civil ecclesiastical law about the Agreement (Intesa), signed in 2010 by the Regione Siciliana and the Regione Ecclesiastica Sicilia, aimed at the protection, preservation and development of the ecclesiastical cultural heritage. By moving from the specialty of the Sicilian model in regulating and administrating such heritage, and by analyzing its effects on the specific system that regulates the same ecclesiastical component, the primary goal is to focus on the atypical elements carried onto the Agreement, which appear to be connected to the practice of such special prerogatives by the Regional Government; and paying particular attention to those rules which, aside from not reflecting the equivalent ones carried instead onto the national Agreement (Intesa), may also reveal the respect of autonomous guidelines in front of the Agreement (Accordo) of Villa Madama. The final goal is then to clarify both the crux of the actual correspondence between such a peculiar reference and the concordatarian system, and the wideness of the powers pertaining, into such a system, to a Region holding special competence

Automatic analysis of multiple Beerkan infiltration experiments for soil Hydraulic Characterization

The BEST (Beerkan Estimation of Soil Transfer parameters) procedure of soil hydraulic characterization appears promising for intensively sample field areas with a reasonable effort both in terms of equipment and time passed in the field. Two alternative algorithms, i.e. BEST-slope and BEST-intercept, have been suggested to determine soil sorptivity and field-saturated soil hydraulic conductivity from a simply measured cumulative infiltration curve. With both algorithms, calculations have to be repeated also many times, depending on the number of collected infiltration data, that should vary between eight and 15. The need to consider a varying number of infiltration data is related to the fact that the infiltration model used in BEST is valid for the transient phase of the process, and only experimental data representative of this phase of the infiltration process have to be selected. The fitting of the theoretical model to the data is carried out by minimizing the sum of the squared residuals between estimated and measured infiltration data. Therefore, analyzing a single run may demand a lot of time, since many calculations have to be carried out. This circumstance complicates soil hydraulic characterization based on an intensive soil sampling, and it also increases the risk to make mistakes. These problems are expected to be substantially reduced, or even eliminated, if an automatic procedure of data analysis is applied. The general objective of this investigation was to develop an automatic data processing tool to easily and rapidly analyze databases including several BEST runs. The developed tool makes use of the Microsoft Excel Solver add-in routine. A Visual Basic for Applications (VBA) macro was written to automate creation and manipulation of Microsoft Excel Solver models. A looping structure was used in the VBA macro to automate data analysis of BEST experiments. The developed tool can be viewed as a practically useful contribution to an expeditious, intensive soil hydraulic characterization, also in terms of analysis of the collected data

Thermo-mechanical and micro-structural characterization of shape memory polymer foams

Shape memory polymer (SMP) materials have the ability to remain in a deformed state and then recover their initial/cast shape. This property has significant potential in many different fields, including aerospace and bio-medical, in which a shape change is desirable and actuation may not be required. SMP materials have been made into nano-reinforced composites and also foamed to improve desired properties for specific applications. SMP foams offer two clear advantages over non-foam SMP materials in applications for the biomedical and aerospace fields. The key advantages are lower density and significant compressibility. The significance of this is that components made out of SMP foam are lighter than traditional SMP materials, more compressible and exhibit minimal transverse change during deformation and shape recovery. This increases the performance and efficiency of devices using SMP foam material. The need for a set of design criteria, models, and limits for the use of shape memory polymer foams was proposed. The effect of temperature and strain on the mechanical behavior, compression, tensile, cyclic compression, constrained recovery and free strain recovery of the material was used to determine the operational limits of the material. Next, the damage mechanism and viscoelastic effects in compressive cycling were determined through further mechanical testing and with the incorporation of three dimensional structure mapping via micro-CT scanning. The influence of microstructure was determined by testing the basic thermomechanical, viscoelastic and shape recovery behavior of foams with relative densities of 20, 30 and 40 percent. A similar suite of tests was then performed on the base epoxy material to generate the material properties necessary to fit constitutive equations to enable computational modeling. This data was then combined with three dimensional microstructures generated from micro-CT scans to develop material models for shape memory foams. These models were then validated by comparing model results to the experimental results under similar conditions.Ph.D.Committee Chair: Gall, Ken; Committee Co-Chair: McDowell, David; Committee Member: Guldberg, Robert; Committee Member: Sanderson, Terry; Committee Member: Shofner, Meisha; Committee Member: Tannenbaum, Rin

Light scattering as an easy tool to measure vesicles weight concentration

Over the last few decades, liposomes have emerged as promising drug delivery systems and effective membrane models for studying biophysical and biological processes. For all applications, knowing their concentration after preparation is crucial. Thus, the development of methods for easily controlling vesicles concentration would be of great utility. A new assay is presented here, based on a suitable analysis of light scattering intensity from liposome dispersions. The method, tested for extrusion preparations, is precise, easy, fast, non-destructive and uses a tiny amount of sample. Furthermore, the scattering intensity can be measured indifferently at different angles, or even by using the elastic band obtained from a standard spectrofluorimeter. To validate the method, the measured concentrations of vesicles of different matrix compositions and sizes, measured by light scattering with different angles and instruments, were compared to the data obtained by the standard Stewart assay. Consistent results were obtained. The light scattering assay is based on the assessment of the mass fraction lost in the preparation, and can be applied for methods such as extrusion, homogenization, French press and other microfluidic procedures

Thévenin's Battery Model Parameter Estimation Based on Simulink

Lithium-ion batteries (LIB) proved over time to be one of the best choices among rechargeable batteries. Their small size, high energy density, long life, and low maintenance need make them a prominent candidate for the role of the most widespread energy storage system. They have the potential to monopolize the green technology sector. An accurate definition of the parameters defining the behaviour of the battery in different operating conditions is thus essential, as their knowledge proves crucial in certain fields such as those that involve electric vehicles. This paper proposes the estimation of the values of the parameters of the Thevenin equivalent circuit of a LIB commercial cell. Experimental data obtained through constant current charge/discharge cycles are analysed through a Simulink model, and results are obtained as a function of the state of charge (SOC) for a fixed and controlled temperature value. The results achieved with the proposed model can monitor the salient parameters of the equivalent circuit with an error between 7 and 10%