Metal objects mapping after small charge explosions. A study on AISI 304Cu steel with two different grain sizes

Evidence of exposure of a metal component to a small charge explosion can be detected by observing microstructural modifications; they may be present even if the piece does not show noticeable overall plastic deformations. Particularly, if an austenitic stainless steel (or another metal having a face-centered cubic structure and a low stacking fault energy) is exposed to an explosive shock wave, high-speed deformation induces primarily mechanical twinning, whereas, in nonexplosive events, a lower velocity plastic deformation first induces slip. The occurrence of mechanical twins can be detected even if the surface is damaged or oxidized in successive events. In the present research, optical metallography (OM) and scanning electron microscopy (SEM), and scanning tunneling microscopy (STM) were used to detect microstructural modifications caused on AISI 304Cu steel disks by small-charge explosions. Spherical charges of 54.5 or 109 g TNT equivalent mass were used at explosive-to-target distances from 6.5 to 81.5 cm, achieving peak pressures from 160 to 0.5 MPa. Explosions induced limited or no macro-deformation. Two alloy grain sizes were tested. Surface OM and SEM evidenced partial surface melting, zones with recrystallization phenomena, and intense mechanical twinning, which was also detected by STM and X-ray diffraction. In the samples' interior, only twins were seen, up to some distance from the explosion impinged surface and again, at the shortest charge-to-sample distances, in a thin layer around the reflecting surface. For forensic science locating purposes after explosions, the maximum charge-to-target distance at which the phenomena disappear was singled out for each charge or grain size and related to the critical resolved shear stress for twinning.     

Omens of an early winter: The proportional vote and the changing Italian party system

Abstract The proportional arena has been designed as a buffer and corrective for the hard verdicts of the new Italian plurality system. However, the political impact of this arena is much deeper than its purely electoral role. It measures the loadings of single parties within coalitions and, subsequently, influences their interactions and bargaining tactics. The elections of April 1996 clearly show the effects of institutional learning by the different actors involved: voters, coalitions, candidates, etc. The analysis of electoral data shows the following main findings: (a) the remarkable equilibrium between left–wing and right–wing coalitions; (b) the gains made by the left thanks to its better ability to manage alliances with the centre and extreme left; (c) surprisingly little change in voter behaviour between 1994 and 1996, and most of what change there is deriving from vote nationalization. The main features of Italian electoral geography are also confirmed.     

How to lose a majority: the competition in single–member districts

Abstract Few observers expected that the 1966 elections in Italy would yield a clear–cut outcome. Even fewer people expected that, after the disastrous results of the previous elections, the centre–left coalition would be able to gain a majority of seats in both branches of Parliament. Yet this is precisely what happened on 21 April 1996. This article tries to explain the comeback of the 1994 losers by focusing on three factors which have changed the electoral balance between the two major coalitions in the single–member districts. The first factor was the ability of the centre–left coalition (Ulivo–RC) to broaden its range while its major rival (the Polo) lost key allies. The result has been a more competitive stand of centre–left candidates, particularly in the North. The Polo lost the support of the Lega Nord and suffered the split of the Movimento Sociale on its right. These defections, along with others, led to the loss of a considerable number of seats. Finally, the Polo also suffered from the defection of a considerable number of its voters who voted for one of the parties of the centre–right coalition in the proportional arena, but refused to vote for the Polo candidate in the single–member districts. We conclude by suggesting a number of hypotheses that could explain this split–ticket phenomenon.     

Political Fragmentation and Fiscal Outcomes

In this paper we develop the analysis ofthe effects on political fragmentation onfiscal policy in a number of ways. Weanalyze three kinds of fragmentation: sizeand control, institutional and over timefragmentation. In doing so we introduce anumber of new variables that allow us tolook at this issue in a broader way. At thesame time we have tackled somemethodological problems that affectedprevious analyses, using a panel of 19 OECDcountries over 1975–1995. Overall we findrelatively poor evidence in favor of sizeand over time fragmentation, and moreevidence of institutional and controlfragmentation.     

Testing for Structural Change in Cointegrated Relationships: Analysis of Price–Wages Models for Poland and Hungary

In previous studies concerning short- and long-run relationships for price–wage models, the cointegration analysis has been developed assuming the existence of a unique cointegration parametrisation. These empirical results reveal the presence of significant relationships, both in the short and in the long run, among prices, wages, labour productivity and exchange rate. In this paper we intend to develop the possibility of a more general type of cointegration, allowing for a change at an unknown time period in the sample. At this end we will consider mainly the long-run relationship among these variables using the testing procedure suggested by Gregory and Hansen (1996a,b). This permits us to consider a multivariate extension of the endogenous break univariate approach and, in the meantime, this enables us to test for cointegration in the presence of possible structural breaking cointegrated relationships under the alternative. The empirical analysis of a multivariate model for price–wage relationship both for Poland and Hungary, over the period 1970–1996, is presented and discussed.     

Artifacts Caused by Leaf-Cutting Ants of the Genus Atta (Hymenoptera: Formicidae): Postmortem Bite Injuries and the Tearing of Clothes

Ants are one of the first insects to find an exposed cadaver and can be present during all stages of decomposition. Although these organisms are not commonly used in postmortem interval estimates, they are to be taken into account on criminal investigations involving human corpses, since they can leave bite marks that can be mistaken for antemortem or perimortem injuries, which could be misleading when ascertaining the occurrence of abuse or physical altercation during a crime. A few studies report the action of ants on human cadavers and even though leaf-cutting ants of the genus Atta are frequently encountered in succession studies that use animal carcasses, there are no records of these fungus-growing species on human corpses. Atta is a genus restricted to the New World, ranging from northern Argentina to southern United States and acts as one of the most conspicuous neotropical herbivores. In this study, we report three cases of violent death that illustrate the impact of ants, especially those of the genus Atta, in a forensic setting. We compare the patterns displayed by postmortem bite injuries caused by leaf-cutter ants and other common species with less robust mandibles. We also present the capability of Atta ants to create artifacts by cutting victim’s clothes in a crime scene, contributing to the knowledge of ant-mediated confounding factors in crime scene investigation.     

Women and Men who Committed Murder: Male/Female Psychopathic Homicides

The present study was designed to compare gender differences in psychiatric diagnosis with the dimension of psychopathy in women and men who had attempted or committed homicide. The study samples consisted of 39 homicidal females and 48 homicidal males who were confined in one of Italy’s REMS or prison facilities in two southern provinces of Italy (Puglia and Basilicata). Assessment instruments included the SCID-5, the PID-5 IRF, and the PCL-R. Each gender group was stratified according to the level of criminal responsibility for the homicidal offense (full, partial, absent), and after assessments, according to the degree of the psychopathic dimension. There were clear gender differences in homicidal individuals. Female offenders were less likely to have had a record of criminal charges/convictions or imprisonment, and their homicides were more often intrafamilial, victimizing especially of their children, whereas males targeted intimate partners and extrafamilial victims. In the entire group, there was an inverse relationship between the level of psychopathy and the personality disorder on one side, and the psychotic disturbance on the other. Factor 2 (lifestyle/antisocial dimension) of the PCL-R was higher among the homicidal males, whereas females tended to score higher on Factor 1 (the interpersonal/affective dimension). Finally, if the psychopathic dimension is a qualifier for antisocial personality disorder, as indicated in DSM-5, this appears to be less true for females who tend to have other personality disorders.     

Corruption around the world: an analysis by partial least squares—structural equation modeling

Public Choice - This paper contributes to the empirical research on corruption in three ways. From a methodological viewpoint, it applies partial least squares–structural equation modeling to...     

Political competition and economic performance: evidence from the Italian regions

We verify the predictions of the theoretical literature on the relationship between political competition and economic performance, holding that, when the predominance of an ideological dimension creates a political rent, the party exploiting it selects lower quality politicians whose policy choices worsen economic performance. We examine the sample of 15 Italian Regions from 1980 to 2002 that exploits the institutional reforms of 1995 as an exogenous shock to pre-existing rents. We find evidence that higher political competition improves economic performance, through the choice of more efficiency-oriented policies.