We present a pole expansion for the propagators in the framework of normalized quantum electrodynamics and compare it with the more canonical results from S-matrix theory.

Is sociology inherently a mode of secular materialism? Or, are there intellectual resources deep within the sociological tradition, expansively conceived, that offer the sociological imagination a spiritual `post-secular' perspective on society and culture? This article draws out the subterranean theological stream of sociological consciousness and illuminates a `sacramentalist' socio-theology with particular reference to the `iconic vision' of Paul Evdokimov. In the context of late modernity, such a radical emphasis on the sacred foundations and transcendent potentialities of life provides the possibility (...) of a fundamental critique of commodified profane culture and of sociology itself. (shrink)

This paper discusses the role of age in scientific practice from an ethical perspective. In social perception, people tend to categorise others rather automatically along three major dimensions: race, sex, and age.1 Much empirical and theoretical attention has been devoted to the study of racism and sexism, but comparatively little research in the social and behaviural sciences has been directed at understanding what some refer to as the third ‘-ism’: ageism.2 For a serious understanding of the implications of ageism in (...) science, it is necessary to discuss, first, the conflicting relationships between classical and modern concepts of time and calendar age, and thereafter the concept of ageism. (shrink)

The formation of particles of elemental tin in association with the nucleation of the precipitate phase θ′ in an Al–1.7 at.% Cu–0.01 at.% Sn alloy has been investigated by high resolution transmission electron microscopy. Analysis of lattice images has demonstrated that these tin particles associated with θ′ platelets formed during short-term ageing (typically 3 min at 200 degrees Celcius) exhibit a crystallographic form that is distinctly different from that previously reported in such ternary alloys and also from that observed in (...) the binary alloy Al–0.01 at.% Sn. Those tin particles that could be clearly identified as β-Sn phase shared a crystallographic relationship of the form (001)Sn‖(001)Al‖(001)θ′, [110]Sn‖[100]Al‖[100]θ′ with the α-Al and θ′ phases with which they were simultaneously in contact. The observations imply that, while tin may assist nucleation of platelets of θ′, the formation of θ′ equally influences the crystallography of β--Sn that forms in association with θ′. Following prolonged ageing (typically 50 h at 200°C), the β-Sn particles in contact with θ′ plates had coarsened and diminished in number, and most now exhibited an orientation relationship with α-Al matrix similar to that observed in the binary alloy Al–0.01 at.% Sn (i.e. (100)Sn‖(111)Al, [010]Sn‖[112]Al) and to that previously observed in the later stages of ageing of the ternary alloy Al–1.7 at.% Cu–0.01 at.% Sn. (shrink)