Monopolistic Competition with Two-Part Tariffs

Non-uniform pricing equilibria are shown to dominate uniform pricing equilibria in free entry, monopolistically competitive markets with identical consumers. The non-uniform pricing equilibrium is welfare optimal. Comparisons of Cournot and non-uniform pricing equilibria in terms of the equilibrium number of firms and sales per firm show that the positioning of Cournot equilibria relative to the welfare optimal configuration of firms and outputs depends on the relative curvatures of inverse demand and average cost functions, entry-induced rotation of inverse demand functions, and the relative price effects of changes in own and other firms outputs. The choice between the non-uniform and uniform pricing interpretations of equilibria in differentiated product markets may have important implications for policy analysis

Studies of Mass and Size Effects in Three-Dimensional Vibrofluidized Granular Mixtures

We examine the steady state properties of binary systems of driven inelastic hard spheres. The spheres, which move under the influence of gravity, are contained in a vertical cylinder with a vibrating base. We computed the trajectories of the spheres using an event-driven molecular dynamics algorithm. In the first part of the study, we chose simulation parameters that match those of experiments performed by Wildman and Parker. Various properties computed from the simulation including the density profile, granular temperature and circulation pattern are in good qualitative agreement with the experiments. We then studied the effect of varying the mass ratio and the size ratio independently while holding the other parameters constant. The mass and size ratio are shown to affect the distribution of the energy. The changes in the energy distributions affect the packing fraction and temperature of each component. The temperature of the heavier component has a non-linear dependence on the mass of the lighter component, while the temperature of the lighter component is approximately proportional to its mass. The temperature of both components is inversely dependent on the size of the smaller component.Comment: 14 Pages, 12 Figures, RevTeX

Rigidity analysis of HIV-1 protease

We present a rigidity analysis on a large number of X-ray crystal structures of the enzyme HIV-1 protease using the 'pebble game' algorithm of the software FIRST. We find that although the rigidity profile remains similar across a comprehensive set of high resolution structures, the profile changes significantly in the presence of an inhibitor. Our study shows that the action of the inhibitors is to restrict the flexibility of the beta-hairpin flaps which allow access to the active site. The results are discussed in the context of full molecular dynamics simulations as well as data from NMR experiments.Comment: 4 pages, 3 figures. Conference proceedings for CMMP conference 2010 which was held at the University of Warwic

Variable temperature study of the crystal and magnetic structures of the giant magnetoresistant materials LMnAsO (L=La, Nd)

Peer reviewedPublisher PD

Inserting Components into Geometries Constructed onto a Non-Standard Substrate for Electronics Packaging

Additive manufacturing (AM) has matured from its initial concept as a prototyping technique to an industrial manufacturing process. Consequently, AM processes must meet relevant standards for an increasing number of applications. Here, we investigate inserting components into geometries constructed onto a silicon nitride substrate, using stereolithography (SLA), for the purpose of electronics packaging. Compared to conventional processes, SLA avoids high temperatures and stresses while permitting much greater flexibility to arrange components in three dimensions. This facilitates an increased feature density and the construction of packages for use in complex spaces. A characteristic of interest to this application, is the SLA material-substrate interaction and the resulting quality of adhesion. The adhesion mechanism between SLA and silicon nitride is investigated and substantially enhanced by a pre-treatment process. A process for then inserting large and complex geometries and components into the SLA build process is identified and compliance of the product with relevant standards is reviewed.Mechanical Engineerin

“I wouldn't survive it, as simple as that”: Syndemic vulnerability among people living with chronic non-communicable disease during the COVID-19 pandemic

The co-occurrence of COVID-19, non-communicable diseases and socioeconomic disadvantage has been identified as creating a syndemic: a state of synergistic epidemics, occurring when co-occurring health conditions interact with social conditions to amplify the burden of disease. In this study, we use the concept of illness management work to explore the impact of the COVID-19 pandemic on the lives of people living with, often multiple, chronic health conditions in a range of social circumstances. In-depth interviews were conducted between May and July 2020 with 29 participants living in a city in North East England. Qualitative data provide unique insights for those seeking to better understand the consequences for human life and wellbeing of the interacting social, physical and psychological factors that create syndemic risks in people's lives. Among this group of people at increased vulnerability to harm from COVID-19, we find that the pandemic public health response increased the work required for condition management. Mental distress was amplified by fear of infection and by the requirements of social isolation and distancing that removed participants' usual sources of support. Social conditions, such as poor housing, low incomes and the requirement to earn a living, further amplified the work of managing everyday life and risked worsening existing mental ill health. As evidenced by the experiences reported here, the era of pandemics will require a renewed focus on the connection between health and social justice if stubborn, and worsening health and social inequalities are to be addressed or, at the very least, not increased