England’s Electronic Prescription Service: Infrastructure in an Institutional Setting

We describe the development of the Electronic Prescription Service (EPS), the solution for the electronic transmission of prescriptions adopted by the English NHS for primary care. The chapter is based on both an analysis of data collected as part of a nationally commissioned evaluation of EPS, and on reports of contemporary developments in the service. Drawing on the notion of an installed infrastructural base, we illustrate how EPS has been assembled within a rich institutional and organizational context including causal pasts, contemporary practices and policy visions. This process of assembly is traced using three perspectives; as the realization and negotiation of constraints found in the wider NHS context, as a response to inertia arising from limited resources and weak incentive structures, and as a purposive fidelity to the existing institutional cultures of the NHS. The chapter concludes by reflecting on the significance of this analysis for notions of an installed base

Coarsening of second phase in a two-phase Zr-2.5Nb: On the role of phase boundaries

Deformed two-phase Zr-2.5Nb was subjected to 700 degrees C annealing and associated coarsening. After primary recrystallization, the second-phase body-centered cubic beta was well dispersed on the grain boundaries of hexagonal alpha matrix. Prolonged annealing led to the presence of the beta, mainly at the alpha tri-junctions. The two-phase coarsening was associated with clear trends of widening in the second-phase size distribution and changes in phase boundary nature. The former is contrary to what is expected. Changes in phase boundary nature were through increased concentration of 45 degrees[0 0 1] phase boundaries-good-fit interfaces, present in larger beta particles, which were estimated to have higher three-dimensional lattice coincidence and hence lower energy. Simple analytical modeling, assuming dissolution-controlled particle coarsening and a lower interfacial energy of the phase interface with the 45 degrees[0 0 1], was shown to explain these experimental observations. (C) 2009 Acta Materialia Inc

Annealing related microstructural developments in a two-phase ZR-2.5 NB alloy

Deformed/pilgered two-phase, 10-15% cubic second phase - rest being primary hexagonal phase, Zr-2.5 Nb alloy was subjected to various annealing treatments treatments ranging from recovery to recrystallization and grain growth. Associated microstructural developments were monitored through combinations of characterization techniques - bulk crystallographic texture & microtexture measurements and estimations of lattice strain and residual stress. Significant texture changes were associated only with grain growth of the primary phase - a process facilitated by second phase coarsening. From nearly continuous presence at the primary phase grain boundaries, latter stages of grain growth had shown coarsened second phase present only at the tri-junctions. This process was associated with significant changes in phase-boundary nature. An effort was made to explain such changes from an 'extended', i. e. extended to phase boundaries, CSL (coincident site lattice) theory

Defining recrystallization in pilgered Zircaloy-4: From preferred nucleation to growth inhibition

Pilgered Zircaloy-4 was subjected to recrystallization annealing at 650 degrees C: temperature sufficient for primary recrystallization but inadequate for noticeable competitive grain coarsening. Associated microstructural developments were monitored through bulk and microtexture measurements. The deformed microstructure had two, generalized, types of grains: fragmenting/deforming and non-fragmenting/non-deforming. The former had higher stored energy of cold work and defined the early recrystallization stages through preferred nucleation. Non-fragmenting grains, on the other hand, did not contribute directly to recrystallization: but provided significant growth inhibition or pinning to the recrystallized grains. A combination of these two mechanisms defined the recrystallization behavior of pilgered Zircaloy-4. (C) 2011 Elsevier B.V. All rights reserved