Endogenous Lobbying

In this paper we endogenize the number and characteristics of lobbies in a citizen-candidate model of representative democracy where citizens can lobby an elected policy-maker. We find that lobbying always matters. That is, lobbying always affects equilibrium policy outcomes. Moreover, only one policy outcome emerges in equilibrium. An "extremist" candidate is elected and implements a "centrist" policy that differs from the one most preferred by the median voter. These results are in contrast with the ones obtained in the context of a citizen-candidate model where lobbies are exogenous.LOBBYING; ELECTIONS

Investigation on some factors affecting crack formation in high resistance aluminum alloys

Aluminum alloys having good mechanical properties are Al-Zn-Mg alloys (7xxx) and Al-Cu-Li alloys (Weldalite®). These alloys may be subjected to stress corrosion cracking. In order to overcome this problem the Al 7050 alloy has been developed and it is widely used for aerospace applications. Despite that, some components made of this alloy cracked during the manufacturing process including machining and chemical anodization. In a previous work cracked Al 7050 components have been analyzed in order to identify possible causes of crack formation. In this work the susceptibility of this alloy to intergranular corrosion has been analysed and compared with that of other high resistance aluminum alloys

Statute law or case law?.

We embed a simple contracting model with ex-ante investments in which there is scope for Court intervention in a full-blown open-ended dynamic setting. The underlying preferences of both Courts and contracting parties are fully forward looking and unbiased. Our point of departure is instead the observation that when Courts intervene in a contractual relationship they obviously do so at the ex-post stage. This introduces a natural tension between actual Court behavior and ex-ante optimal Court decisions. In a Case Law regime each Court is tempted to behave myopically because, ex-post, this affords current extra gains from trade. This temptation is traded off against the effect of its ruling, as a precedent, on future ones. We model the Statute Law regime in an extreme way: no discretion is left to the Courts which behave according to fixed rules. This solves the time-inconsistency problem afflicting the Case Law Courts, but is costly because of its lack of flexibility. We find that when the nature of the environment changes sufficiently often through time the Case Law regime is superior, while when the environment does not change very often the Statute Law regime dominates. Overall, our findings support the view that the Case Law regime is superior in fields in which innovation, and hence change, is central (e.g. finance), while the Codified Law regime is superior in more slow-changing ones (e.g. inheritance law).

Time decay of scaling invariant Schroedinger equations on the plane

We prove the sharp L^1-L^{\infty} time-decay estimate for the 2D-Schroedinger equation with a general family of scaling critical electromagnetic potentials.Comment: 26 page

Fracture behaviour of alloys for a new laser ranged satellite

A new laser-ranged satellite called LARES 2 (Laser Relativity Satellite 2) has been recently designed for accurate tests of Einsten's theory of General Relativity and space geodesy. Some high density alloys (8.6-9.3 g/dm3) have been studied and characterised for producing the LARES 2 passive satellite. The considered materials were Copper and Nickel based alloys that have been produced and characterised. Aim of this work was to analyse their fracture behaviour that is a requirement for materials to be used for space applications. Fracture tests have been carried out on several specimens and fracture surfaces have been analysed

Time decay of scaling critical electromagnetic Schr\"odinger flows

We obtain a representation formula for solutions to Schr\"odinger equations with a class of homogeneous, scaling-critical electromagnetic potentials. As a consequence, we prove the sharp $L^{1}\to L^{\infty}$ time decay estimate for the 3D-inverse square and the 2D-Aharonov-Bohm potentials.Comment: 32 pages, 1 figur

Study of defect formation in Al 7050 alloys

The Al 7050 alloy is an Al-Zn-Mg-Cu-Zr alloy having good mechanical properties. This alloy has been developed in order to overcome stress corrosion cracking problems that characterise 7xxx Al alloys. Despite Al 7050 is widely used for aerospace applications, it can be subjected to crack initiation and propagation during the manufacturing process. In this work cracked Al 7050 components have been analysed in order to identify possible causes of crack formation such as coarse intermetallic phase presence, voids or wrong mechanical machining processes

Massive Protoplanetary Disks in the Trapezium Region

(abridged) We determine the disk mass distribution around 336 stars in the young Orion Nebula cluster by imaging a 2.5' x 2.5' region in 3 mm continuum emission with the Owens Valley Millimeter Array. For this sample of 336 stars, we observe 3 mm emission above the 3-sigma noise level toward ten sources, six of which have also been detected optically in silhouette against the bright nebular background. In addition, we detect 20 objects that do not correspond to known near-IR cluster members. Comparisons of our measured fluxes with longer wavelength observations enable rough separation of dust emission from thermal free-free emission, and we find substantial dust emission toward most objects. For the ten objects detected at both 3 mm and near-IR wavelengths, eight exhibit substantial dust emission. Excluding the high-mass stars and assuming a gas-to-dust ratio of 100, we estimate circumstellar masses ranging from 0.13 to 0.39 Msun. For the cluster members not detected at 3 mm, images of individual objects are stacked to constrain the mean 3 mm flux of the ensemble. The average flux is detected at the 3-sigma confidence level, and implies an average disk mass of 0.005 Msun, comparable to the minimum mass solar nebula. The percentage of stars in Orion surrounded by disks more massive than ~0.1 Msun is consistent with the disk mass distribution in Taurus, and we argue that massive disks in Orion do not appear to be truncated through close encounters with high-mass stars. Comparison of the average disk mass and number of massive dusty structures in Orion with similar surveys of the NGC 2024 and IC 348 clusters constrains the evolutionary timescales of massive circumstellar disks in clustered environments.Comment: 27 pages, including 7 figures. Accepted by Ap