Optimised materials

Vergara F.E., 2002. An evolutionary algorithm for optimising material flow in supply chains. Computers Industrial Engineering, 43,407-421. 

Combining optimised materials to form buildtech composite materials... 

The industrial aim is to optimise materials, with a special bias among the Rolduc group to maximise the use of polymer composites. The scientific message must be that this is a total system problem. 

It is therefore clear that in a SOFC there are many processes that require optimised materials, and consequently the SOFC is a complex solid state device. As a summary, it is essential that the electrolyte is a gas tight, pure ionic conductor stable over a wide pOz range (>10 " atm). Anodes have to possess stability in reducing conditions with both high ionic and electronic conductivity, and chemical compatibility with the electrolyte material. Similar properties are required for the cathode with the exception that stabUity is now in oxidising environments. 

The optimised results indicated a material blend of 60 % BB7755 and 40 % RPET, a preform cooling time of 4.5 s, a blow time of 7 s. with a mould temperature of 80 °C. Given that the nrould temperature indicates a non significant dqtendence at these low temperatures, subsequence experiments are conducted for mould temperatures between 120 - 150 "C for the optimised material blend utilising optimised process conditions as indicated above. 

Materials suitable as filter aids include diatomaceous earth, expanded perilitic rock, asbestos, ceUulose, nonactivated carbon, ashes, ground chalk, or mixtures of those materials. The amount of body feed is subject to optimisa tion, and the criterion for the optimisa tion depends on the purpose of the filtration. Maximum yield of filtrate per unit mass of filter aid is probably most common but longest cycle, fastest flow, or maximum utilisation of cake space are other criteria that requite a different rate of body feed addition. The tests to be carried out for such optimisation normally use laboratory or pilot-scale filters, and must include variation of the filtration parameters such as pressure or cake thickness in the optimisation. 

In electrolytic processes, the anode is the positive terminal through which electrons pass from the electrolyte. Anode design and selection of anode materials of constmction have traditionally been the result of an optimisation of anode cost and operating economics, in addition to being dependent on the requirements of the process. Most materials used in metal anode fabrication are characteristically expensive use has, however, been justified by enhanced performance and reduced operating cost. An additional consideration that has had increasing influence on selection of the appropriate anode is concern for the environment (see Electrochemical processing). 

Processing temperatures should not exceed 180°C, and the duration of time that the material is in the melt state should be kept to a minimum. At the end of a run the processing equipment should be purged with polyethylene. When blow moulding, the blow pin and mould should be at about 60°C to optimise crystallisation rates. Similarly, injection moulds are recommended to be held at 60 5 C. 

These kinds of maps and optimisation approaches represent impressive applications of the quantitative revolution to purposes in materials engineering. 

The advent of the integrated circuit and its foundry has now firmly integrated materials scientists into modern electronics, their function both to optimise production processes and to resolve problems. To cite Just one example, many materials scientists have worked on the problem of clectronugraiion in the thin metallic conductors built into integrated circuits, a process which eventually leads to short circuits and circuit breakdown. At high current densities, migrating electrons in... 

Co-design—(http //www.montell. com / montell/products/p-codesign.html) active involvement in product design to optimise the use of material and manufacturing resources. 

The expert tried to optimise the design of unbreakable crockery. First he wanted to find reasons for using ceramic as the main material in terms of desired properties. From this first step, he concluded that ceramic had some advantages over metals or composites. The expert made a sharp distinction between intrinsic and extrinsic properties. The choice of type of ceramics was not relevant becanse the desired properties are extrinsically determined. Thns relevant properties cannot be much influenced by the difference in bonding strength due to the different types of ions of the material. Consequently, the properties of ceramic crockery are not mnch inflnenced by the actual choice of ceramic material. Because of this, the expert did not inclnde the ionic stmcture in his reasoning. When he was asked why he did not nse this snb-microscopic level, he explained it was not necessary becanse this [the desired properly] is not imdeigoing influences at atomic level at all . 

Computer simulations therefore have several inter-related objectives. In the long term one would hope that molecular level simulations of structure and bonding in liquid crystal systems would become sufficiently predictive so as to remove the need for costly and time-consuming synthesis of many compounds in order to optimise certain properties. In this way, predictive simulations would become a routine tool in the design of new materials. Predictive, in this sense, refers to calculations without reference to experimental results. Such calculations are said to be from first principles or ab initio. As a step toward this goal, simulations of properties at the molecular level can be used to parametrise interaction potentials for use in the study of phase behaviour and condensed phase properties such as elastic constants, viscosities, molecular diffusion and reorientational motion with maximum specificity to real systems. Another role of ab initio computer simulation lies in its interaction... 

Jorgensen et al. has developed a series of united atom intermolecular potential functions based on multiple Monte Carlo simulations of small molecules [10-23]. Careful optimisation of these functions has been possible by fitting to the thermodynamic properties of the materials studied. Combining these OPLS functions (Optimised Potentials for Liquid Simulation) with the AMBER intramolecular force field provides a powerful united-atom force field [24] which has been used in bulk simulations of liquid crystals [25-27],... 

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