Integrated engineering environments for large complex products

An introduction is given to the Engineering Design Centre at the University of Newcastle upon Tyne, along with a brief explanation of the main focus towards large made-to-order products. Three key areas of research at the Centre, which have evolved as a result of collaboration with industrial partners from various sectors of industry, are identified as (1) decision support and optimisation, (2) design for lifecycle, and (3) design integration and co-ordination. A summary of the unique features of large made-to-order products is then presented, which includes the need for integration and co-ordination technologies. Thus, an overview of the existing integration and co-ordination technologies is presented followed by a brief explanation of research in these areas at the Engineering Design Centre. A more detailed description is then presented regarding the co-ordination aspect of research being conducted at the Engineering Design Centre, in collaboration with the CAD Centre at the University of Strathclyde. Concurrent Engineering is acknowledged as a strategy for improving the design process, however design coordination is viewed as a principal requirement for its successful implementation. That is, design co-ordination is proposed as being the key to a mechanism that is able to maximise and realise any potential opportunity of concurrency. Thus, an agentoriented approach to co-ordination is presented, which incorporates various types of agents responsible for managing their respective activities. The co-ordinated approach, which is implemented within the Design Co-ordination System, includes features such as resource management and monitoring, dynamic scheduling, activity direction, task enactment, and information management. An application of the Design Co-ordination System, in conjunction with a robust concept exploration tool, shows that the computational design analysis involved in evaluating many design concepts can be performed more efficiently through a co-ordinated approach

Nature’s nations: the shared conservation history of Canada and the USA

Historians often study the history of conservation within the confines of national borders, concentrating on the bureaucratic and political manifestations of policy within individual governments. Even studies of the popular expression of conservationist ideas are generally limited to the national or sub-national (province, state, etc.) scale. This paper suggests that conservationist discourse, policy and practice in Canada and the USA were the products of a significant cross-border movement of ideas and initiatives derived from common European sources. In addition, the historical development of common approaches to conservation in North America suggests, contrary to common assumptions, that Canada did not always lag behind the USA in terms of policy innovation. The basic tenets of conservation (i.e. state control over resource, class-based disdain for subsistence hunters and utilitarian approaches to resource management) have instead developed at similar time periods and along parallel ideological paths in Canada and the USA

NOVEL SMECTIC POLYMORPHIC BEHAVIOUR IN HOMOLOGOUS SERIES OF MESOGENS

La grande alternation des températures de transition qui sépare les états nématiques et liquides de la série de 4-(4'-phénylbenzalamino) cinnamates de ω-phénylealkyle quand on parcourt la série homologue a été encore augmentée en introduisant dans l'anneau phényle du groupe ω-phénylealkyle des substituants méthyle- ou chlor- aux positions 3"- ou 4"-. Les phases nématiques se trouvent seulement quand il y a un nombre pair (n) des groupes méthylènes dans la chaîne alkylène. Il y a aussi une alternation des points de transition smectiques dans chacune des quatre séries. Cependant, la stabilité thermique des phases smectiques A diminue et celle des phases smectiques B augmente quand on passe de n pair à n impair. Dans quelques cas cet effet fait coïncider les limites supérieures de stabilité thermique des phases smectiques A et B, pour les valeurs impaires de n. On observe alors une texture microscopique toute nouvelle à la transition du liquide smectique. Bien qu'on ne puisse pas observer une transition de la phase smectique A à la phase smectique B par la microscopie ou par A. T. D., l'étude des mélanges indique qu'une phase smectique A transitionnelle existe encore. Ceci suggère qu'il est nécessaire qu'une phase smectique A transitionnelle se forme entre le liquide amorphe (I) et la phase smectique B, quand on chauffe ou que l'on refroidit ces matériaux. Nous avons appelé cette transition SAB-I. Nous avons observé aussi les phases smectiques E pour beaucoup des seize esthers nouveaux, et la stabilité thermique des phases E, comme celle des phases smectiques B, grandit pour les valeurs impaires de n. Les effets relatifs des substituants 3"- et 4"-méthyle- et chlor- sur la stabilité thermique des phases nématiques, smectiques A, smectiques B et smectiques E sont aussi discutés.The high alternation of nematic thermal stabilities found in the series of ω-phenylalkyl 4-(4'-phenylbenzylideneamino) cinnamates as the homologous series was ascended has been further exaggerated by substituting the terminal phenyl ester ring with methyl or chloro substituents in the 3"- or 4"-positions. Nematic phases were found only when an even number (n) of methylene units occurred in the alkylene chain. Smectic thermal stabilities also alternated as each of the four series of esters was ascended. However, the smectic A thermal stabilities decreased and the smectic B thermal stabilities increased on passing from even to odd values of n. In some cases this caused the thermal stabilities of the smectic A and B phases to coincide for odd values of n. When this occurred, a unique texture was observed microscopically at the I-S transition. Although no SA-SB transition could be detected microscopically or by D. T. A., miscibility studies indicated that a transitional SA phase still existed. This suggests that it is necessary to form a transitional SA phase intermediate between the amorphous liquid and a SB phase, both on heating and cooling. This transition has been called SAB-I. Smectic E phases were also found for many of the sixteen new esters, and the thermal stabilities of SE phases, like those of SB phases, increased for odd values of n. The relative effects of 3"- and 4"-methyl- and chloro-substituents on N, SA, SB and SE thermal stabilities are discussed

Polymerization of 1-Octene by a Pyridylamidohafnium Catalyst: A SEC, 1H-NMR and Small Angle Neutron Scattering Study

We assayed the polymerization of I-octene in toluene-d(8) polymerized by a pyridylamidohafnium catalyst precursor activated by the cocatalyst tris(pentafluorophenyl)boron. In situ small angle neutron scattering and H-1 NMR spectroscopy were used together with time-resolved SEC to investigate the polymerization process. The catalyst system contains several polymerization active species. About 98% of the active catalyst is of uniform activity. file resulting polymers show relatively narrow molecular weight distributions. The residual catalyst exhibits an increased activity, leading to the formation of notably higher molecular weights than is generated by the majority of available active centers. With the help of NMR and SEC results the small angle neutron scattering data could he interpreted quantitatively. Good agreement was found between the expected scattering profile for nonaggregated chains and their measured counterparts. At no stage during the polymerization process could more than single polymer chains be detected