Navier-Stokes analysis of transonic cascade flow

A new kind of C-type grid is proposed, this grid is non-periodic on the wake and allows minimum skewness for cascades with high turning and large camber. Reynolds-averaged Navier-Stokes equations are solved on this type of grid using a finite volume discretization and a full multigrid method which uses Runge-Kutta stepping as the driving scheme. The Baldwin-Lomax eddy-viscosity model is used for turbulence closure. A detailed numerical study is proposed for a highly loaded transonic blade. A grid independence analysis is presented in terms of pressure distribution, exit flow angles, and loss coefficient. Comparison with experiments clearly demonstrates the capability of the proposed procedure

Multigrid calculation of three-dimensional viscous cascade flows

A 3-D code for viscous cascade flow prediction was developed. The space discretization uses a cell-centered scheme with eigenvalue scaling to weigh the artificial dissipation terms. Computational efficiency of a four stage Runge-Kutta scheme is enhanced by using variable coefficients, implicit residual smoothing, and a full multigrid method. The Baldwin-Lomax eddy viscosity model is used for turbulence closure. A zonal, nonperiodic grid is used to minimize mesh distortion in and downstream of the throat region. Applications are presented for an annular vane with and without end wall contouring, and for a large scale linear cascade. The calculation is validated by comparing with experiments and by studying grid dependency

N=1* model superpotential revisited (IR behaviour of N=4 limit)

The one-loop contribution to the superpotential, in particular the Veneziano-Yankielowicz potential in N=1 supersymmetric Yang-Mills model is discussed from an elementary field theory method and the matrix model point of view. Both approaches are based on the Renormalization Group variation of the superconformal N=4 supersymmetric Yang-Mills model.Comment: 31 page

The Role of Guarantees in support of Entrepreneurial Microcredit in Italy.

This paper proposes an empirical analysis of the microcredit initiatives promoted by local and cooperative credit banks trying to take advantage of any differences in the initiatives promoted by other types of operators in terms of default rates of loans. The differences are analyzed on the basis of distinctive features to identify a possible way of developing microcredit in Italy. The empirical analysis verifies the existence of a statically significant correlation between characteristics of the entrepreneurial microcredit programs and their default risk. The presence of credit guarantee schemes and the role of banking intermediaries as promoters reduce significantly the risk of default on these initiatives. The Italian microcredit programs do not show territorial differences.

A new species of Bolbelasmus Boucomont, 1911 (Insecta Coleoptera Geotrupidae) from Sicily (Italy).

Authors have examined all available sicilian specimens belonging to the genus Bolbelasmus, collected between 1893 and 2010, previously identified as B. gallicus e B. unicornis. They conclude that both species have to be excluded from the sicilian fauna and describe the new species B. romanorum, which is characterized by peculiar punctures on the clypeus, the head and the pronotum, and by the shape of the clypeus, the head and the aedeagus sclerites. They compare the new species with all the taxa currently known in the Mediterranean. Further, they show oscillograms of both sexes of the new species, which, as other Bolbelasmus, stridulates vigorously; they also detect for the first time the pars stridens, consisting in a series of small bristles on the lower outer border of wings; the insect emits its sound moving actively the abdomen, the friction of the wing on the first abdominal tergite, particularly swollen, produces the stridulation

Bio-logic: gene expression and the laws of combinatorial logic

Original article can be found at: http://www.mitpressjournals.org/ Copyright MIT Press DOI: 10.1162/artl.2008.14.1.121At the heart of the development of fertilized eggs into fully formed organisms and the adaptation of cells to changed conditions are genetic regulatory networks (GRNs). In higher multi-cellular organisms, signal selection and multiplexing is performed at the cis-regulatory domains of genes, where combinations of transcription factors (TFs) regulate the rates at which the genes are transcribed into mRNA. To be able to act as activators or repressors of gene transcription, TFs must first bind to target sequences on the regulatory domains. Two TFs that act in concert may bind entirely independently of each other, but more often binding of the first one will alter the affinity of the other for its binding site. This paper presents a systematic investigation into the effect of TF binding dependencies on the predicted regulatory function of this “bio-logic”. Four extreme scenarios, commonly used to classify enzyme activation and inhibition patterns, for the binding of two TFs were explored: independent (the TFs bind without affecting each other’s affinities), competitive (the TFs compete for the same binding site), ordered (the TFs bind in a compulsory order), and joint binding (the TFs either bind as a preformed complex, or binding of one is virtually impossible in the absence of the other). The conclusions are: 1) the laws of combinatorial logic hold only for systems with independently binding TFs; 2) systems formed according to the other scenarios can mimic the functions of their Boolean logical counterparts, but cannot be combined or decomposed in the same way; and 3) the continuously scaled output of systems consisting of competitively binding activators and repressors can be more robustly controlled than that of single TF or (quasi-) logical multi-TF systems. Keywords: Transcription regulation, Genetic regulatory networks, Enzyme kinetics, Combinatorial logic, Non-Boolean continuous logic, Modelling.Peer reviewe

Il ruolo delle banche locali e del relationship lending in scenari economici in profondo cambiamento

Lo scopo di questo lavoro \ue8 quello di esaminare la relazione tra banca locale e impresa in un contesto economico in profondo cambiamento. L\u2019obiettivo \ue8 comprendere se e come l\u2019orientamento all\u2019attivit\ue0 di finanziamento delle banche locali (pi\uf9 radicate nel territorio e pi\uf9 vicine ai principi del relationship lending) sia cambiato in seguito allo scoppio della crisi finanziaria

EUROPE 2020 SI-LAB: A New Center for Economic and Social Development in Sicily

The debate on the determinants of regional and local development has been stimulated recently by the European strategy for smart, sustainable and inclusive growth defined as Europe 2020. We present the objectives and structure of a new laboratory (SI-LAB) for the development of Sicilian economy promoted by the University of Palermo. In particular, we highlight the fundamental issues related to the incoming functioning of the Lab as a new oganization devoted to analyzing public policy issues, and fostering new ways of entrepreurship at the local level

Colour, copies and confinement

In this paper we construct a wide class of Gribov copies in Coulomb gauge SU(2) gauge theory. Infinitesimal copies are studied in some detail and their non-perturbative nature is made manifest. As an application it is shown that the copies prevent a non-perturbative definition of colour charge.Comment: 25 pages, 10 figures. Minor changes, two references added. Published versio

A Drought Alert system based on seasonal forecasts

Water resources are under stress in many areas of the world, because of a combination of climatic and anthropogenic factors. The Mediterranean area is one of the regions mostly vulnerable to climate alterations. These alterations have direct impacts on the surface water balance and groundwater recharge, and thus changes in the reservoir inputs and the management of water utilities (WUs) are severe challenges for water resources in the future. However, WUs management routines scarcely consider climate information and are based on the stationarity assumption, working on weekly or daily time scale. The use of seasonal forecasts for guiding a strategic planning of the resources has been increasing across several climate-sensitive sectors, including water management and energy. This is due to the fact that it is generally preferred to focus on the upcoming season rather than taking decisions on the basis of a 100-year climate projection. The project EUPORIAS promoted the use of climate information for decision support by involving both providers and potential users of seasonal data. It was demonstrated that seasonal forecasts may give important contributions in the fields of drought-risk assessment and mid-term reservoir management. This study aims at providing some insights in using seasonal forecasts to derive supporting information for water management decision-makers based on drought assessment. Indeed, the exploitation of climate information as precipitation in a mid-term scale, as the seasonal scale, allows for understanding the possible shifts in water resource availability. In this study we describe some results obtained for a case study in Greece