Structure and Properties of Simple and Aggregate Systems by Circular Dichroism Spectroscopy

This thesis deals with the investigation of structural properties of many different systems via Electronic Circular Dichroism (ECD). The interpretation of experimental data has been carried out mainly with quantum-chemistry methods, such as Density Functional Theory (DFT), on both solution and solid-state systems. The analysis of solution systems is oriented towards applications on biologically active compounds, both natural or synthetic, and its objective is to underline the key role of these approaches in the determination of the absolute configuration and the difficulties that may be encountered in case of flexible molecules. Solid-state measurements represent an attractive alternative to these cases where a lot of conformations are present, but difficulties in the interpretation of the signals due to solid-state interactions which are not observable in solution may be faced. For a better understanding of spectral lineshapes, more detailed analyses have been performed taking into account vibronic effects, which may also assist in the determination of the conformational situation of the investigated substrate. The limitations of the vibronic treatment for coupled electronic states have been considered, leading to a general all-coordinate approach which allows simulating the electronic spectrum of “dimeric” molecules with weakly coupled electronic states through a time dependent approach

Squeezed K^+ K^- correlations in high energy heavy ion collisions

The hot and dense medium formed in high energy heavy ion collisions may modify some hadronic properties. In particular, if hadron masses are shifted in-medium, it was demonstrated that this could lead to back-to-back squeezed correlations (BBC) of particle-antiparticle pairs. Although well-established theoretically, the squeezed correlations have not yet been discovered experimentally. A method has been suggested for the empirical search of this effect, which was previously illustrated for phi-phi pairs. We apply here the formalism and the suggested method to the case of K^+ K^- pairs, since they may be easier to identify experimentally. The time distribution of the emission process plays a crucial role in the survival of the BBC's. We analyze the cases where the emission is supposed to occur suddenly or via a Lorentzian distribution, and compare with the case of a Levy distribution in time. Effects of squeezing on the correlation function of identical particles are also analyzed.Comment: 9 pages and 6 figures (figures 2 to 6 contain 4 plots each). Paragraph added to text, figures 2 to 6 revised for improving visualizatio

Cognitive abilities and portfolio choice

We study the relation between cognitive abilities and stockholding using the recent Survey of Health, Ageing and Retirement in Europe (SHARE), which has detailed data on wealth and portfolio composition of individuals aged 50+ in 11 European countries and three indicators of cognitive abilities: mathematical, verbal fluency, and recall skills. We find that the propensity to invest in stocks is strongly associated with cognitive abilities, for both direct stock market participation and indirect participation through mutual funds and retirement accounts. Since the decision to invest in less information-intensive assets (such as bonds) is less strongly related to cognitive abilities, we conclude that the association between cognitive abilities and stockholding is driven by information constraints, rather than by features of preferences or psychological traits

Heat Convection of Compressible Viscous Fluids. I.

The stationary problem for the heat convection of compressible fluid is considered around the equilibrium solution with the external forces in the horizontal strip domain z_0 < z < z_0 + 1 and it is proved that the solution exists uniformly with respect to z_0 larger than Z_0 . The limit system as z_0 goes to infinity is the Oberbeck-Boussinesq equation

The Quality of Health Care: Evidence from Italy

We provide evidence that the quality of health care affects health outcomes, exploiting the substantial variability in the quality of the Italian public health service. The data are drawn from the 2001 Survey of Health, Aging and Wealth (SHAW), a joint venture of the Universities of Padua, Salerno, Venice and Tilburg, providing detailed information on health status, medical expenditure and use of hospitals and other health facilities, as well as detailed demographic and economic variables, for a sample of about 2000 individuals older than 50. The correlation between quality of health care and health outcomes is also confirmed in the panel section of the 1993-95 Bank of Italy Survey of Household Income and Wealth, which allows us to measure the impact of quality by controlling explicitly for regional effects.

Nonlinear stability of liquid flow down an inclined plan

A modified energy method is proposed to study the nonlinear stability of Poiseuille flow with upper free boundary St, down an inclined plane. Sufficient conditions on Reynolds, and Weber numbers, on the slope of the plane, together with the periodicity along the line of maximum slope are given. All constants are computable. Smallness condition on initial data is required

Bounds on repayment behavior: evidence for the consumer credit market

How does the punishment for default affect repayment behavior? We use administrative data, provided by the leading Italian lender of unsecured credit to the household sector, to analyze households repayment behavior. Administrative data are particularly well suited to study what factors are responsible for default, but raise a fundamental econometric problem, since they identify the determinants of repayment behavior only for those who are granted credit. To overcome this problem, we provide upper and lower bounds on the determinants of repayment behavior. Moreover, we show how to use the restrictions from the theory to narrow the bounds.Manski Bounds, Consumer Credit, Default

Possible Origin of RHIC R_{out}/R_{sid} HBT Results

The effects of opacity of the nuclei together with a blackbody type of emission along the system history are considered as a means to explain the ratio $R_{out}/R_{sid}$ observed by STAR and PHENIX collaborations at RHIC. Within our model, no flow is required to explain the data trend of this ratio for large surface emissivities.Comment: 4 pages, 2 Postscript figures, uses espcrc1.sty. Talk presented at Quark Matter 2002, Nantes, France, July 18-24, 2002; to appear in the proceedings (Nucl. Phys. A