Suchergebnisse

Prepared for Directorate of Military Construction Office, Chief of Engineers. ; Bibliography: p. 14-15. ; Mode of access: Internet. ; Water Resources Collections and Archives (WRCA).

Tests of general strain theory (Agnew, 1992) have focused primarily on the relationship between strain and crime, ignoring the intervening role of negative emotions and legitimate coping strategies. This research provides a more comprehensive test of general strain theory, including measures of both anger and other expressions of negative affect, as well as a measure of legitimate coping. Results suggest that strain, negative emotions, and legitimate coping are all related, although not always in the expected direction. Moreover, results indicate that the nature of the link among these three variables and criminal outcomes are shaped by the types of strain and negative affect individuals experience, and by sex differences in the links among central variables.

This paper tests Agnew's (1992) general strain theory (GST) of crime and delinquency. GST argues that strain occurs when others (1) prevent or threaten to prevent you from achieving positively valued goals, (2) remove or threaten to remove positively valued stimuli that you possess, or (3) present or threaten to present you with noxious or negatively valued stimuli. The impact of such strain on delinquency is said to be conditioned by several variables, such as association with delinquent peers and self‐efficacy. Data from a sample of 1,380 New Jersey adolescents provide qualified support for the theory; strain measures of the type described above have a relatively substantial effect on delinquency and drug use. Further, the effect of these strain measures is conditioned by delinquent peers and self‐efficacy, as predicted by GST.

Strain rate dependent deformation behaviours of selective laser melted Alloy 718 (IN718) are systematically studied at 550 and 650 °C by slow strain rate testing, with a forged counterpart as a reference. Selective laser melted IN718 shows significant susceptibility to intergranular cavitation, resulting in ductility degradation with decreasing strain rate. Detailed fractography and cross section inspections are employed to identify the damage mechanisms. Creep rates are also estimated and compared with the conventional counterparts. The possible critical factors for the inferiority of time dependent damage resistance of selective laser melted IN718 are discussed. ; Funding: Faculty grant SFOMATLiU from Linkoping University [200900971]; Swedish Governmental Agency for Innovation Systems (Vinnova)Vinnova [2016-05175]

This thesis focuses on the high strain rate behavior of Maraging steel 300, High Hardness Armor (HHA) and Aluminum 5083 – H131 Alloy. These materials are used by the Department of National Defense (DND) of Canada as armor plate materials in military applications. The aim of the research is to investigate the dynamic shear-strain response of these armor materials at high strain rate loading to study the occurrence of Adiabatic Shear Bands and the subsequent failure. The effects of impact momentum and strain rates on the dynamic stress-strain curve and on the adiabatic shear failure of these armor materials under impact and torsion loading need to be investigated to evaluate their capability to withstand military conditions. ; May 2010

As a representative of immiscible alloy systems, the Cu-Ta system was the research topic because of its potential application in industry, military and defense fields. In this study, an amorphous Cu-Ta alloy film was manufactured through magnetron sputter deposition, which was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Mechanical properties of Cu-Ta film were detected by the nanoindentation method, which show that the elastic modulus of Cu3.5Ta96.5 is 156.7 GPa, and the hardness is 14.4 GPa. The nanoindentation process was also simulated by molecular dynamic simulation to indicate the deformation mechanism during the load-unload stage. The simulation results show that the structure and Voronoi cells decreased by 0.1% at 50 Ps and then remained at this value during the nanoindentation process. In addition, the number of dislocations vary rapidly with the depth between indenter and surface. Based on the experimental and simulation results, the Voronoi structural changes and dislocation motions are the key reasons for the crystallization of amorphous alloys when loads are applied.