Revisiting the carrier-phase source-term formulation in mixed Lagrangian-Eulerian particle models

The formulation of the carrier-phase momentum and enthalpy source terms in mixed Lagrangian-Eulerian models of particle-laden flows is frequently reported inaccurately. Under certain circumstances, this can lead to erroneous implementations, which violate physical laws. A particle- rather than carrier-based approach is suggested for a consistent treatment of these terms.

Hydrocarbon field size distributions: a case study in mixed integer nonlinear programming

Of key importance to oil and gas companies is the size distribution of fields in the areas that they are drilling. Recent arguments suggest that there are many more fields yet to be discovered in mature provinces than had previously been thought because the underlying distribution is monotonic not peaked. According to this view the peaked nature of the distribution for discovered fields reflects not the underlying distribution but the effect of economic truncation. This paper contributes to the discussion by analysing up-to-date exploration and discovery data for two mature provinces using the discovery-process model, based on sampling without replacement and implicitly including economic truncation effects. The maximum likelihood estimation involved generates a high-dimensional mixed-integer nonlinear optimization problem. A highly efficient solution strategy is tested, exploiting the separable structure and handling the integer constraints by treating the problem as a masked allocation problem in dynamic programming.

Complexity of mixed shop scheduling problems: A survey

We survey recent results on the computational complexity of mixed shop scheduling problems. In a mixed shop, some jobs have fixed machine orders (as in the job shop), while the operations of the other jobs may be processed in arbitrary order (as in the open shop). The main attention is devoted to establishing the boundary between polynomially solvable and NP-hard problems. When the number of operations per job is unlimited, we focus on problems with a fixed number of jobs.

A mixed Eulerian-Lagrangian approach for metal extrusion

In this paper a mixed Eulerian-Lagrangian approach for the modelling metal extrusion processes is presented. The approach involves the solution of non-Newtonian fluid flow equations in an Eulerian context, using a free-surface algorithm to track the behaviour of the workpiece and its extrusion. The solid mechanics equations associated with the tools are solved in Lagangrian context. Thermal interactions between the workpiece are modelled and a fluid-structure interaction technique is employed to model the effect of the fluid traction load imposed by the workpiece on the tools. Two extrusion test cases are investigated and the results obtained show the potential of the model with regard to representing the physics of the process and the simulation time.

Aqueous solution of anionic surfactants mixed with soils show a synergistic reduction in surface tension

Water retention and transport in soils is dependent upon the surface tension of the aqueous phase. Surfactants present in aqueous solution reduce the surface tension of aqueous phase. In soil–water systems, this can result in water drainage and reductions in field capacity and hydraulic conductivity. In this investigation, the surface tension of surfactant solutions mixed with soil—in a constant fixed ratio—was measured as a function of surfactant concentration. Two anionic surfactants were used: sodium dodecyl sulphate and sodium bis (2-ethylhexyl) sulfosuccinate. Two soils were also used—a clay soil and a sandy soil. The key observation made by this investigation was that the addition of soil to the surfactant solution provided a further component of surface tension reduction. Neither soil sample reduced the surface tension of water when surfactant was absent from the aqueous phase, though both soils released soil organic matter at low surfactant concentrations as shown by measurement of the chemical oxygen demand of the supernatant solutions. Furthermore, both surfactants were shown to be weakly adsorbed by soil as shown by the use of a methylene blue assay. It is therefore proposed that the additional reduction in surface tension arises from synergistic interactions between the surfactants and dissolved soil organic matter.

Psyche and the arts: Jungian approaches to music, architecture, literature, painting and film

Does art connect the individual psyche to history and culture? Psyche and the Arts challenges existing ideas about the relationship between Jung and art, and offers exciting new dimensions to key issues such as the role of image in popular culture, and the division of psyche and matter in art form. Divided into three sections - Getting into Art, Challenging the Critical Space and Interpreting Art in the World - the text shows how Jungian ideas can work with the arts to illuminate both psychological theory and aesthetic response. Psyche and the Arts offers new critical visions of literature, film, music, architecture and painting, as something alive in the experience of creators and audiences challenging previous Jungian criticism. This approach demonstrates Jung’s own belief that art is a healing response to collective cultural norms. This diverse yet focused collection from international contributors invites the reader to seek personal and cultural value in the arts, and will be essential reading for Jungian analysts, trainees and those more generally interested in the arts. [From the Publisher]