Search

The widespread use and development of inertia friction welding is currently restricted by an incomplete understanding of the deformation mechanisms and microstructure evolution during the process. Understanding phase transformations and lattice strains during inertia friction welding is essential for the development of robust numerical models capable of determining optimized process parameters and reducing the requirement for costly experimental trials. A unique compact rig has been designed and used in‐situ with a high‐speed synchrotron X‐ray diffraction instrument to investigate the microstructure evolution during inertia friction welding of a high‐carbon steel (BS1407). At the contact interface, the transformation from ferrite to austenite was captured in great detail, allowing for analysis of the phase fractions during the process. Measurement of the thermal response of the weld reveals that the transformation to austenite occurs 230 °C below the equilibrium start temperature of 725 °C. It is concluded that the localization of large strains around the contact interface produced as the specimens deform assists this non‐equilibrium phase transformation. [ABSTRACT FROM AUTHOR]

The Connecticut Valley–Gaspé (CVG) trough represents a major, orogen‐scale Silurian–Devonian basin of the Northern Appalachians. From Gaspé Peninsula to southern New England, the CVG trough has experienced a contrasting metamorphic and structural evolution during the Acadian orogeny. Along its strike, the CVG trough is characterized by increasing strain and polyphase structures, and by variations in the intensity of regional metamorphism and contrasting abundance of c. 390–370 Ma granitic intrusions. In southern Quebec and northern Vermont, a series of NW–SE transects across the CVG trough have been studied in order to better understand these along‐strike variations. Detailed structural analyses, combined with phase equilibria modelling, Raman spectrometry, and muscovite 40Ar/39Ar dating highlight a progressive and incremental deformation involving south–north variation in the timing of metamorphism. Deformation evolves from a D1 crustal thickening event which originates in Vermont and progresses to southern Québec where it peaked at 0.6 GPa/380°C at c. 375 Ma. This was followed by a D2 event associated with continuous burial in Vermont from 378 to 355 Ma, which produced peak metamorphic conditions of 0.85 GPa/380°C and exhumation in Quebec from 368 to 360 Ma. The D3 compressional exhumation event also evolved from south to north from 345 to 335 Ma. D1 to D3 deformation events form part of a continuum with an along‐strike propagation rate of ~50 km/Ma During D1, the burial depth varied by more than 15 km between southern Quebec and Vermont, and this can be attributed to the occurrence of a major crustal indenter, the Bronson Hill Arc massif, in the New England segment of the Acadian collision zone. [ABSTRACT FROM AUTHOR]

This article sets out to establish whether, and to what extent, homicides involving social networking sites ( SNSs) are unique and to identify the ways in which perpetrators of homicide have used SNSs in their crimes. It does so by identifying and analysing relevant cases of homicide from around the world and comparing the characteristics of these cases with the general literature on homicide. We argue that the cases in our sample are largely typical of homicide in general and identify six ways in which homicide perpetrators have used SNSs - as reactors, informers, antagonists, predators, fantasists and imposters. [ABSTRACT FROM AUTHOR]

A series of light-harvesting conjugated polymers were designed and synthesized for polymer solar cells. These newly designed polymers comprise an unusual two-dimensional conjugated structure with an electron-rich thiophene-triphenylamine backbone and stable planar indacenodithiophene π-bridges terminated with tunable electron acceptors. It was found that the electron-withdrawing strength of the acceptor could be used to manipulate the energy level of the lowest unoccupied molecular orbital and bandgap (as much as 0.3 eV), generating derivatives with complementary absorbance in the visible spectrum. This approach provides great flexibility in fine tuning the electronic and optical properties of the resultant polymers and facilitates the investigation of how these chemical modifications alter the subsequent photovoltaic properties of these materials. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 [ABSTRACT FROM AUTHOR]