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.

Modeling of ingot development during the start-up phase of direct chill casting

Direct chill (DC) casting is a core primary process in the production of aluminum ingots. However, its operational optimization is still under investigation with regard to a number of features, one of which is the issue of curvature at the base of the ingot. Analysis of these features requires a computational model of the process that accounts for the fluid flow, heat transfer, solidification phase change, and thermomechanical analysis. This article describes an integrated approach to the modeling of all the preceding phenomena and their interactions.

Enhancing the usability of numerical models with case-based reasoning

Numerical models are important tools used in engineering fields to predict the behaviour and the impact of physical elements. There may be advantages to be gained by combining Case-Based Reasoning (CBR) techniques with numerical models. This paper considers how CBR can be used as a flexible query engine to improve the usability of numerical models. Particularly they can help to solve inverse and mixed problems, and to solve constraint problems. We discuss this idea with reference to the illustrative example of a pneumatic conveyor problem. The paper describes example problems faced by design engineers in this context and the issues that need to be considered in this approach. Solution of these problems require methods to handle constraints in both the retrieval phase and the adaptation phase of a typical CBR cycle. We show approaches to the solution of these problesm via a CBR tool.

Unstructured staggered mesh methods for fluid flow, heat transfer and phase change

Unstructured grid meshes used in most commercial CFD codes inevitably adopt collocated variable solution schemes. These schemes have several shortcomings, mainly due to the interpolation of the pressure gradient, that lead to slow convergence. In this publication we show how it is possible to use a much more stable staggered mesh arrangement in an unstructured code. Several alternative groupings of variables are investigated in a search for the optimum scheme.

Multiphysics simulation of microwave processing using a multidomain coupled solver approach

Microwave processing of materials is numerically simulated using a coupled solver approach. Microwave heating is a complex coupled process due to the variation in dielectric properties during heating. The effects of heating an object in a electromagnetic field directly influence the manner in which it interacts with the field. Simplifying assumptions and empirical solutions do not capture the fundamental physics involved and, in general, do not provide usefully accurate solutions in a number of practical problems. In order to capture the underlying processes involved in microwave heating, the problem must be looked at in a holistic manner rather than a number of discrete processes. This contribution outlines a coupled-solver multiphysics analysis approach to the solution of practical microwave heating problems.

An architectural approach to autonomics and self-management of automotive embedded electronic systems

Embedded electronic systems in vehicles are of rapidly increasing commercial importance for the automotive industry. While current vehicular embedded systems are extremely limited and static, a more dynamic configurable system would greatly simplify the integration work and increase quality of vehicular systems. This brings in features like separation of concerns, customised software configuration for individual vehicles, seamless connectivity, and plug-and-play capability. Furthermore, such a system can also contribute to increased dependability and resource optimization due to its inherent ability to adjust itself dynamically to changes in software, hardware resources, and environment condition. This paper describes the architectural approach to achieving the goals of dynamically self-configuring automotive embedded electronic systems by the EU research project DySCAS. The architecture solution outlined in this paper captures the application and operational contexts, expected features, middleware services, functions and behaviours, as well as the basic mechanisms and technologies. The paper also covers the architecture conceptualization by presenting the rationale, concerning the architecture structuring, control principles, and deployment concept. In this paper, we also present the adopted architecture V&V strategy and discuss some open issues in regards to the industrial acceptance.

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.

Vibrational spectroscopy and DFT calculations of di-amino acid cyclic peptides. Part I: cyclo(Gly-Gly), cyclo(L-Ala-L-Ala) and cyclo(L-Ala-Gly) in the solid state and in aqueous solution

Investigations of the vibrational spectra of cyclo(Gly-Gly), cyclo(L-Ala-L-Ala) and cyclo(t-Ala-Gly) are reported. Raman scattering and Fourier transform infrared (FTIR) spectra of solid-state and aqueous protonated samples, as well as their corresponding N-deuterated isotopomers, have been examined. In addition, density functional theory (DFT) (B3-LYP/cc-pVDZ) calculations of molecular structures and their associated vibrational modes were carried out. In each case, the calculated structures of lowest energy for the isolated gas-phase molecules have boat conformations. Assignments have been made for the observed Raman and FTIR vibrational bands of the cyclic di-amino acid peptides (CDAPs) examined. Raman polarization studies of aqueous phase samples are consistent with C-2 and C-1 symmetries for the six-membered rings of cyclo(L-Ala-L-Ala) and cydo(L-Ala-Gly), respectively. There is a good correlation between experimental and calculated vibrational bands for the three CDAPs. These data are in keeping with boat conformations for cydo(L-Ala-L-Ala) and cyclo(L-Ala-Gly) molecules, predicted by the ab initio calculations, in both the solid and aqueous solution states. However, Raman spectroscopic results might infer that cyclo(L-AlaGly) deviates only slightly from planarity in the solid state. The potential energy distributions of the amide I and II modes of a cis-peptide linkage are shown to be significantly different from those of the trans-peptides. For example, deuterium shifts have shown that the cis-amide I vibrations found in cyclo(Gly-Gly), cyclo(L-Ala-L-Ala), and cyclo(L-Ala-Gly) have larger N-H contributions compared to their trans-amide counterparts. Compared to trans-amide II vibrations, cis-amide II vibrations show a considerable decrease in N-H character.

Vibrational spectroscopic studies of the structure of di-amino acid peptides. Part II: cyclo(L-Asp-L-Asp) in the solid state and in aqueous solution

Solid-state protonated and N,O-deuterated Fourier transform infrared (IR) and Raman scattering spectra together with the protonated and deuterated Raman spectra in aqueous solution of the cyclic di-amino acid peptide cyclo(L-Asp-L-Asp) are reported. Vibrational band assignments have been made on the basis of comparisons with previously cited literature values for diketopiperazine (DKP) derivatives and normal coordinate analyses for both the protonated and deuterated species based upon DFT calculations at the B3-LYP/cc-pVDZ level of the isolated molecule in the gas phase. The calculated minimum energy structure for cyclo(L-Asp-L-Asp), assuming C-2 symmetry, predicts a boat conformation for the DKP ring with both the two L-aspartyl side chains being folded slightly above the ring. The C=O stretching vibrations have been assigned for the side-chain carboxylic acid group (e.g. at 1693 and 1670 cm(-1) in the Raman spectrum) and the cis amide I bands (e.g. at 1660 cm(-1) in the Raman spectrum). The presence of two bands for the carboxylic acid C=O stretching modes in the solid-state Raman spectrum can be accounted for by factor group splitting of the two nonequivalent molecules in a crystallographic unit cell. The cis amide II band is observed at 1489 cm(-1) in the solid-state Raman spectrum, which is in agreement with results for cyclic di-amino acid peptide molecules examined previously in the solid state, where the DKP ring adopts a boat conformation. Additionally, it also appears that as the molecular mass of the substituent on the C-alpha atom is increased, the amide II band wavenumber decreases to below 1500 cm(-1); this may be a consequence of increased strain on the DKP ring. The cis amide II Raman band is characterized by its relatively small deuterium shift (29 cm(-1)), which indicates that this band has a smaller N-H bending contribution than the trans amide II vibrational band observed for linear peptides.

IR/Raman spectroscopy and DFT calculations of cyclic di-amino acid peptides. Part III: comparison of solid state and solution structures of cyclo(L-Ser-L-Ser)

B3-LYP/cc-pVDZ calculations of the gas-phase structure and vibrational spectra of the isolated molecule cyclo(L-Ser-L-Ser), a cyclic di-amino acid peptide (CDAP), were carried out by assuming C-2 symmetry. It is predicted that the minimum-energy structure is a boat conformation for the diketopiperazine (DKP) ring with both L-Beryl side chains being folded slightly above the ring. An additional structure of higher energy (15.16 kJ mol(-1)) has been calculated for a DKP ring with a planar geometry, although in this case two fundamental vibrations have been calculated with imaginary wavenumbers. The reported X-ray crystallographic structure of cyclo(L-Ser-L-Ser), shows that the DKP ring displays a near-planar conformation, with both the two L-Beryl side chains being folded above the ring. It is hypothesized that the crystal packing forces constrain the DKP ring in a planar conformation and it is probable that the lower energy boat conformation may prevail in the aqueous environment. Raman scattering and Fourier-transform infrared (FT-IR) spectra of solid state and aqueous solution samples of cyclo(L-Ser-L-Ser) are reported and discussed. Vibrational band assignments have been made on the basis of comparisons with the calculated vibrational spectra and band wavenumber shifts upon deuteration of labile protons. The experimental Raman and IR results for solid-state samples show characteristic amide I vibrations which are split (Raman:1661 and 1687 cm(-1), IR:1666 and 1680 cm(-1)), possibly due to interactions between molecules in a crystallographic unit cell. The cis amide I band is differentiated by its deuterium shift of ~ 30 cm(-1), which is larger than that previously reported for trans amide I deuterium shifts. A cis amide II mode has been assigned to a Raman band located at 1520 cm(-1). The occurrence of this cis amide II mode at a wavenumber above 1500 cm(-1) concurs with results of previously examined CDAP molecules with low molecular weight substituents on the C-alpha atoms, and is also indicative of a relatively unstrained DKP ring.

The food multimix concept: new innovative approach to meeting nutritional challenges in Sub-Saharan Africa

Food insecurity, chronic hunger, starvation and malnutrition continue to affect millions of individuals throughout the developing world, especially Sub-Saharan Africa. Various initiatives by African governments and International Agencies such as the UN, the industrial nations, the International Monetary Fund, the World Bank and the World Trade Organisation to boost economic development, have failed to provide the much-needed solution to these challenges. The impact of these economic shifts and the failures of structural adjustment programmes on the nutritional well-being and health of the most vulnerable members of poor communities cannot be over-emphasised. The use of ad hoc measures as an adjunct to community-based rural integrated projects have provided little success and will be unsustainable unless they are linked to harnessing available local resources. The present paper therefore focuses on exploring alternative ways of harnessing the scant agricultural resources by employing a scientific approach to food-related problem-solving. The food multimix (FMM) concept offers a scientific contribution alongside other attempts currently in use by the World Food Programme, WHO and FAO to meet the food insecurity challenges that confront most of the developing world in the twenty-first century. It is an innovative approach that makes better use of traditional food sources as a tool for meeting community nutritional needs. The FMM concept employs a food-based approach using traditional methods of food preparation and locally-available, cheap and affordable staples (fruits, pulses, vegetables and legumes) in the formulation of nutrient-enriched multimixes. Developed recipes can provide >= 40% of the daily nutritional requirements of vulnerable groups, including patients with HIV/AIDS and children undergoing nutrition rehabilitation. The FMM approach can also be used as a medium- to long-term adjunct to community-based rural integration projects aimed at health improvement and economic empowerment in Sub-Saharan Africa.

Managing the supply side for product development in China: a Guanxi network approach

Based on the IMP research tradition this paper regards relationships and networks as key issues in the product development and supply management agenda. Within business networks, co-development is only possible to be analysed when emphasis is placed on interdependences and interactive relationships. Co-development usually implies close relationships that allow companies to rely on each other's resources. Close relationships imply interdependences, which may improve companies' technical and product development. By looking at the actual interactions - between a UK company and its Chinese suppliers - that led to an innovative solution and a successful product launch, evolving relationship patterns are identified and analysed in a case study. Both the literature review and case study findings highlight the importance of the 'guanxi' concept (meaning interpersonal relationships in Mandarin) when analysing business-to-business networks in China. Hence, it is suggested that guanxi-based thinking and acting should be incorporated into the interaction model when considering business networking that embrace China. 'Guanxi' broadens the validity of the interaction model, in terms of geographical proximity, and deepens its theoretical base. The case study provides valuable insights for supply management under a product development context in China. In practice, the main point of interest is that Chinese suppliers are important 'resource' providers as well as 'network' providers. Hence, it is suggested that guanxi practice should be reflected into theoretical developments.

Advanced product development integration architecture: an out-of-box solution to support distributed production networks

This paper presents novel collaboration methods implemented using a centralized client/server product development integration architecture, and a decentralized peer-to-peer network for smaller and larger companies using open source solutions. The product development integration architecture has been developed for the integration of disparate technologies and software systems for the benefit of collaborative work teams in design and manufacturing. This will facilitate the communication of early design and product development within a distributed and collaborative environment. The novelty of this work is the introduction of an‘out-of-box’ concept which provides a standard framework and deploys this utilizing a proprietary state-of-the-art product lifecycle management system (PLM). The term ‘out-of-box’ means to modify the product development and business processes to suit the technologies rather than vice versa. The key business benefits of adopting such an approach are a rapidly reconfigurable network and minimal requirements for software customization to avoid systems instability

Assessing the sensitivity of subtidal sedimentary habitats to pressures associated with marine activities. Phase 1 Report: Rationale and proposed ecological groupings for Level 5 biotopes against which sensitivity assessments would be best undertaken.

The purpose of this study is to produce a series of Conceptual Ecological Models (CEMs) that represent sublittoral rock habitats in the UK. CEMs are diagrammatic representations of the influences and processes that occur within an ecosystem. They can be used to identify critical aspects of an ecosystem that may be studied further, or serve as the basis for the selection of indicators for environmental monitoring purposes. The models produced by this project are control diagrams, representing the unimpacted state of the environment free from anthropogenic pressures. It is intended that the models produced by this project will be used to guide indicator selection for the monitoring of this habitat in UK waters. CEMs may eventually be produced for a range of habitat types defined under the UK Marine Biodiversity Monitoring R&D Programme (UKMBMP), which, along with stressor models, are designed to show the interactions within impacted habitats, would form the basis of a robust method for indicator selection. This project builds on the work to develop CEMs for shallow sublittoral coarse sediment habitats (Alexander et al 2014). The project scope included those habitats defined as ‘sublittoral rock’. This definition includes those habitats that fall into the EUNIS Level 3 classifications A3.1 Atlantic and Mediterranean high energy infralittoral rock, A3.2 Atlantic and Mediterranean moderate energy infralittoral rock, A3.3 Atlantic and Mediterranean low energy infralittoral rock, A4.1 Atlantic and Mediterranean high energy circalittoral rock, A4.2 Atlantic and Mediterranean moderate energy circalittoral rock, and A4.3 Atlantic and Mediterranean low energy circalittoral rock as well as the constituent Level 4 and 5 biotopes that are relevant to UK waters. A species list of characterising fauna to be included within the scope of the models was identified using an iterative process to refine the full list of species found within the relevant Level 5 biotopes. A literature review was conducted using a pragmatic and iterative approach to gather evidence regarding species traits and information that would be used to inform the models and characterise the interactions that occur within the sublittoral rock habitat. All information gathered during the literature review was entered into a data logging pro-forma spreadsheet that accompanies this report. Wherever possible, attempts were made to collect information from UK-specific peer-reviewed studies, although other sources were used where necessary. All data gathered was subject to a detailed confidence assessment. Expert judgement by the project team was utilised to provide information for aspects of the models for which references could not be sourced within the project timeframe. A multivariate analysis approach was adopted to assess ecologically similar groups (based on ecological and life history traits) of fauna from the identified species to form the basis of the models. A model hierarchy was developed based on these ecological groups. One general control model was produced that indicated the high-level drivers, inputs, biological assemblages, ecosystem processes and outputs that occur in sublittoral rock habitats. In addition to this, seven detailed sub-models were produced, which each focussed on a particular ecological group of fauna within the habitat: ‘macroalgae’, ‘temporarily or permanently attached active filter feeders’, ‘temporarily or permanently attached passive filter feeders’, ‘bivalves, brachiopods and other encrusting filter feeders’, ‘tube building fauna’, ‘scavengers and predatory fauna’, and ‘non-predatory mobile fauna’. Each sub-model is accompanied by an associated confidence model that presents confidence in the links between each model component. The models are split into seven levels and take spatial and temporal scale into account through their design, as well as magnitude and direction of influence. The seven levels include regional to global drivers, water column processes, local inputs/processes at the seabed, habitat and biological assemblage, output processes, local ecosystem functions, and regional to global ecosystem functions. The models indicate that whilst the high level drivers that affect each ecological group are largely similar, the output processes performed by the biota and the resulting ecosystem functions vary both in number and importance between groups. Confidence within the models as a whole is generally high, reflecting the level of information gathered during the literature review. Physical drivers which influence the ecosystem were found to be of high importance for the sublittoral rock habitat, with factors such as wave exposure, water depth and water currents noted to be crucial in defining the biological assemblages. Other important factors such as recruitment/propagule supply, and those which affect primary production, such as suspended sediments, light attenuation and water chemistry and temperature, were also noted to be key and act to influence the food sources consumed by the biological assemblages of the habitat, and the biological assemblages themselves. Output processes performed by the biological assemblages are variable between ecological groups depending on the specific flora and fauna present and the role they perform within the ecosystem. Of particular importance are the outputs performed by the macroalgae group, which are diverse in nature and exert influence over other ecological groups in the habitat. Important output processes from the habitat as a whole include primary and secondary production, bioengineering, biodeposition (in mixed sediment habitats) and the supply of propagules; these in turn influence ecosystem functions at the local scale such as nutrient and biogeochemical cycling, supply of food resources, sediment stability (in mixed sediment habitats), habitat provision and population and algae control. The export of biodiversity and organic matter, biodiversity enhancement and biotope stability are the resulting ecosystem functions that occur at the regional to global scale. Features within the models that are most useful for monitoring habitat status and change due to natural variation have been identified, as have those that may be useful for monitoring to identify anthropogenic causes of change within the ecosystem. Biological, physical and chemical features of the ecosystem have been identified as potential indicators to monitor natural variation, whereas biological factors and those physical /chemical factors most likely to affect primary production have predominantly been identified as most likely to indicate change due to anthropogenic pressures.

A phase 2 study of high-activity 186Re-HEDP with autologous peripheral blood stem cell transplant in progressive hormone-refractory prostate cancer metastatic to bone

Purpose: We investigated the potential for improvement in disease control by use of autologous peripheral blood stem cell transplant (PBSCT) to permit administration of high activities of 186Re-hydroxyethylidene diphosphonate (HEDP) in patients with progressive hormone-refractory prostate cancer (HRPC).

Methods: Eligible patients had progressive HRPC metastatic to bone, good performance status and minimal soft tissue disease. Patients received 5,000 MBq of 186Re-HEDP i.v., followed 14 days later by PBSCT. Response was assessed using PSA, survival, pain scores and quality of life.

Results: Thirty-eight patients with a median age of 67 years (range 50–77) and a median PSA of 57 ng/ml (range 4–3,628) received a median activity of 4,978 MBq 186Re-HEDP (range 4,770–5,100 MBq). The most serious toxicity was short-lived grade 3 thrombocytopenia in 8 (21%) patients. The median survival of the group is 21 months (95%CI 18–24 months) with Kaplan-Meier estimated 1- and 2-year survival rates of 83% and 40% respectively. Thirty-one patients (81%, 95% CI 66–90%) had stable or reduced PSA levels 3 months post therapy while 11 (29%, 95% CI 15–49%) had PSA reductions of >50% lasting >4 weeks. Quality of life measures were stable or improved in 27 (66%) at 3 months.

Conclusion: We have shown that it is feasible and safe to deliver high-activity radioisotope therapy with PBSCT to men with metastatic HRPC. Response rates and survival data are encouraging; however, further research is needed to define optimal role of this treatment approach.