Public Debt and Economic Growth in Italy

In this paper we investigate the link between government debt-to-GDP ratio and real per capita income growth in Italy over 1861-2009. We model our regression analysis on a standard production function. Our results support the hypotheses of a negative relation between public debt and growth and of a stronger effect of foreign debt compared to domestic debt before World War I. The effect of public debt on growth appears to work mainly through reduced investment. These results help explain the different reaction of per capita GDP growth to the debt-ratio over 1880-1914 (when the negative correlation between the two variables is particularly strong) and 1985-2007 (when the correlation appears to break down when debt starts declining). A descriptive analysis of fiscal policy in these two periods suggests that differences in the timing of fiscal consolidation as well as in the size and composition of the budget are additional explanatory factors.public debt, economic growth, Italian economic history

Italian Public debt since national unification. A reconstruction of the time series

The paper presents the results of a reconstruction of the Italian public debt series since national unification. Computations use today’s statistical methodology to obtain a database consistent with the national accounts. The reference sector is general government, not the state sector, as in many previous studies; the definition refers to consolidated gross debt (within and across subsectors). The database includes monthly times series for overall debt and its breakdowns by instrument and subsector. Given their frequency and length, the new data might be a useful tool for economic historians and students of public economics. The work briefly presents the methodology and describes public debt developments over the last 150 years. Compared with previous data, the new series show higher debt average. The project is completed by a methodological annex in which sources and methods are described in more detail and by a database with monthly time series for the debt, its breakdown by instrument and subsector, and the consolidating items. All three components are available on the Bank of Italy website; in the future the series will be updated monthly and will remain available on the statistical section of the website.public debt, economic history

The rise of pertussis in Malta in 2011 : a case for adolescent and adult pertussis booster vaccination

Notwithstanding the high rates of pertussis infant vaccination coverage in developed countries, Bortedella pertussis infections are manifesting a changing epidemiological pattern of disease. Of notable concern is the rise of pertussis in adolescents and adults. This changing picture is largely attributable to waning immunity after natural infection or vaccination. The belief that pertussis is chiefly a childhood disease is a common misconception. A significant rise of pertussis cases in Malta in older age groups was recorded in 2011. The addition of an adolescent and/or an adult booster dose against pertussis should be strongly considered.peer-reviewe

One-factorizations of the complete graph Kp+1K_{p+1} arising from parabolas

There are three types of affine regular polygons in AG(2, q): ellipse, hyperbola and parabola. The first two cases have been investigated in previous papers. In this note, a particular class of geometric one-factorizations of the complete graph Kn arising from parabolas is constructed and described in full detail. With the support of computer aided investigation, it is also conjectured that up to isomorphisms this is the only one-factorization where each one-factor is either represented by a line or a parabola

On the Preliminary Design and Performance Prediction of Centrifugal Turbopumps—Part 2

The ideal flow model for the preliminary design and performance prediction of radial turbopumps presented in the companion paper of the present volume (d’Agostino et al., 2017) is here interfaced with the calculation of the boundary layers inside the blade channels and other major forms of flow losses, with the aim of developing an effective tool for rapid parametric optimization of the machine performance and geometry under appropriate design constraints, such as assigned values of the specific speed, flow coefficient and blade solidity. A mixed-flow turbopump, with a six-bladed impeller, a vaneless diffuser, a single-spiral volute and nondimensional performance characteristics similar to those typically used in liquid propellant rocket engine feed systems, has been designed, parametrically optimized and manufactured in accordance with the indications of the present model. The pumping and suction performance of the machine have been determined in a series of tests in the Cavitating Pump Rotordynamic Test Facility (CPRTF). Under fully-wetted flow conditions the measured pumping characteristics of the machine (hydraulic head and efficiency as functions of the flow coefficient) proved to be in excellent agreement with the model predictions, thus successfully confirming the validity of the proposed model as an effective tool for rapid and efficient design of high-performance centrifugal turbopumps

A Reduced Order Model for Optimal Centrifugal Pump Design

A reduced order model for preliminary design and noncavitating performance prediction of radial turbopumps has been illustrated in a previous paper presented by the same authors. The model expresses the 3D incompressible, inviscid, irrotational flow through helical blades with slow axial variations of the pitch and backsweep by superposing a 2D cross-sectional axial vorticity correction to a fully-guided flow with axisymmetric stagnation velocity in the meridional plane. Application of the relevant governing equations yields a set of constraints for the axial evolution of the blade pitch and backsweep that allows for the closed form definition of the impeller geometry and flowfield in terms of a reduced number of controlling parameters. In turn, mass and momentum conservation are used to account for the mixing of the flow leaving the impeller and its coupling with 2D reduced order models of the flow in the diffuser (if any) and the volute, thus generating the information necessary for completing the geometric definition of the machine and for determining its ideal noncavitating performance in accordance with the resulting flowfield. In the present paper, the above ideal flow model has been interfaced with the calculation of boundary layers inside the blade channels and other major forms of flow losses, with the aim of developing an effective tool for rapid parametric optimization of the machine geometry and performance under appropriate design constraints such as target values of the specific speed, flow coefficient and impeller blading solidity

A nonlocal phase-field model of Ginzburg-Landau-Korteweg fluids

A thermodynamic model of Korteweg fluids undergoing phase transition and/or phase separation is developed within the framework of weakly nonlocal thermodynamics. Compatibility with second law of thermodynamics is investigated by applying a generalized Liu procedure recently introduced in the literature. Possible forms of the free energy and of the stress tensor, which generalize some earlier ones proposed by several authors in the last decades, are carried out. Owing to the new procedure applied for exploiting the entropy principle, the thermodynamic potentials are allowed to depend on the whole set of variables spanning the state space, including the gradients of the unknown fields, without postulating neither the presence of an energy or entropy extra-flux, nor an additional balance law for microforce

Cavitating Pump Rotordynamic Test Facility at ALTA S.p.A.: Upgraded Capabilities of a Unique Test Rig

The paper illustrates the upgrades recently introduced in Alta’s Cavitating Pump Rotordynamic Test Facility in order to extend its experimental capabilities, with special reference to the addition of an auxiliary pump for testing of turbopump inducers over a wider range of flow coefficients, and the set-up of an original apparatus specifically designed for the characterization of the dynamic transfer matrices of cavitating inducers and turbopumps. Examples are presented of the improved capabilities of the facility

Rotordynamic Forces on a Three Bladed Inducer under Forced Whirl Motion Operating at Different Conditions

The paper illustrates the main results of an experimental campaign conducted in the CPRTF (Cavitating Pump Rotordynamic Test Facility) at ALTA S.p.A., aimed at characterizing the rotordynamic forces acting on a whirling three-bladed, tapered-hub, variable-pitch inducer, named DAPROT3. The forces acting on the impeller have been measured by means of a rotating dynamometer mounted just behind the inducer. The roles of the imposed whirl motion of the rotor, flow coefficient, cavitation number and liquid temperature have been investigated. The results have been obtained by means of a recent experimental technique, consisting in measuring the continuous spectra of the rotordynamic forces as functions of the whirl excitation frequency. This technique allows for extrapolating valuable information from the experiments by more accurately and rapidly characterizing the spectral behavior of these forces than can be obtained from a limited number of point experiments conducted at constant whirl frequency. Therefore, it is useful to better capture the complexity of the rotordynamic forces and assess their consequences on the stability of axial inducers

First record of a hagfish anchored to a living bottlenose dolphin in the Mediterranean Sea

An unusual observation of a hagfish ( Myxine glutinosa ) anchored to a living bottlenose dolphin ( Tursiops truncatus ) was documented in an encounter with a group of about 80 dolphins during an ongoing long-term research program on cetaceans in the central Mediterranean Sea, Italy. The body of the hagfish was observed extruding from the blowhole of the bottlenose dolphin showing a stereotypical surfacing–breathing pattern. The observation lasted 2h; photo-identification, acoustic, and behavioral data were collected. Succorant behaviors (i.e., "standing by") from conspecifics and overlapping vocalizations during social phases were recorded. The dolphin was encountered again after 1 month in the same area without the hagfish, apparently in healthy conditions