The Electronic Structure of Some Second Row Elements in High Oxidation States

The core of the studies presented here is the calculation of numerical self consistent field wave functions for the second row elements Si, P, S, Cl and Ar in excited configurations which involve the 3d orbital. In many discussions of the bonding in molecules which contain these elements as their central atoms,it si maintained that the 3d orbital may have an important role. To take a classic example,on the basis of the concept of hybridisation Pauling has interpreted the bonding in sulphur hexafluoride in terms of the formation by the sulphur atom of sp3d2 hybrids. Later it was observed that the maximum in the 3d wave function, if taken to be of a Slater type, lay well beyond the S-F internuclear distance. On further investigation, the use of the Slater 3d orbital in this context was judged to be quite acceptable and an elaborate theory was developed to bring the 3d orbital into a form suitable for bonding. This situation persisted to the time this work was commenced,though on occasions it had been suggested that perhaps the Slater 3d orbital is not a suitable representation for the 3d wave function of S(sp3d2). In the opening chapter of this thesis,the course of such disputations is placed in perspective against a background of the chemical thought prevailing at the period and the problems involved are formulated. For a satisfying solution it is found to be necessary to perform a series of self consistent field calculations,and to investigate more fully the concept of the valence state. Chapter II treats in detail the theory of the self consistent field and the manner in which atomic calculations are performed. This is followed by a study of the valence state concept utilising the theory of the symmetric permutation group. Some very interesting results are obtained. The subsequent two chapters are concerned with the shape and energy of the valence orbitals possessed by the elements mentioned when in high oxidation states. It is discovered that many affirmations which have been made on the subject of the 3d orbital are unfounded and indeed quite erroneous. This is rather surprising in view of the admirable investigations performed on this topic by Craig and his collaborators during the past decade. Their theories are therefore closely examined in Chapter VI and discrepancies explained. On reaching the closing pages it is possible to suggest in what manner a '3d orbital' might assume a role in the bonding of the second row elements under review. Finally a plea is made that the concept of hybridisation must now give way to the concept of polarisation if the development of chemical thought is not to be inhibited

The use of building simulation within an architectural practice

This paper documents the development and implementation and use of simulation within an architectural practice and reports how its use facilitates the practice's commitment to Sustainable Design

Experience of using building simulation within the design process of an architectural practice

This paper documents work that follows on from a previous study [Morbitzer et al 2001] on the implementation of a simulation-tool into anarchitectural practice at outline design stage. Theuse of simulation is now pervasively and routinely undertaken by designers within the company toevaluate energy and environmental performance oftheir design concepts. The paper documents the changes to the interface, based on the feedback from designers. It includes a case study of how these improvements have impacted on the degree-of-use of the simulation tool by designers, the impact of the tool on the design process and the design outcome, a discussion on the development of the simulation tool, and the issues facing the architectural practice with use of simulation

North Pacific Marine Science Organization (PICES) publications: what's the access and where's the value?

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Integration of building simulation into the design process of an architectural practice

A key barrier to the acceptance of simulation within building design has been identified as the fact that it is not fully integrated into the design process. The project described in this paper attempts to address this barrier by embedding modelling as a standard component of design practice procedures within an architectural practice

Feedback control of intensified fed-batch mammalian cell culture using inline raman spectroscopy

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Scriptor Noster Arabicus Et Tursimany a Jewish Culture Mediator in the Thirteenth-Century Crown of Aragón.

This thesis examines the role of intermediaries and cultural mediators in shaping the relations between the thirteenth-century Crown of Aragón and the Muslim Mediterranean. Exemplified by the life of Abrahim Abenamies, these agents crossed with ease between the cultures, languages, religions, and political environments of the Western Mediterranean. In his role as agent of the Crown, fluidity was an asset for Abenamies and his royal patrons. Fluidity, however, also introduces an impediment for the modern researcher as identity boundaries seem to shift with movement and personal loyalties appear temporary. Because of the dynamic nature of my subject, I rely on the Mediterranean Perspective in order to properly disentangle the webs of actions, loyalties, and responsibilities that enfolded Abenamies. The Mediterranean Perspective provides me with the necessary tools to analyze Abenamies in his proper context as an intermediary and ask questions that highlight the centrality of cultural mediation in the thirteenth-century

Options for the Delivery of Intermittent Preventive Treatment for Malaria to Children: A Community Randomised Trial

Intermittent preventive treatment for malaria in children (IPTc) is a promising new intervention for the prevention of malaria but its delivery is a challenge. We have evaluated the coverage of IPTc that can be achieved by two different delivery systems in Ghana.IPTc was delivered by volunteers in six villages (community-based arm) and by health workers at health centres or at Expanded Programme on Immunisation outreach clinics (facility based) in another six communities. The villages were selected randomly and drugs were administered in May, June, September and October 2006. The first dose of a three-dose regimen of amodiaquine plus sulphadoxine-pyrimethamine was administered under supervision to 3-59 month-old children (n = 964) in the 12 study villages; doses for days 2 and 3 were given to parents/guardians to administer at home.The proportion of children who received at least the first dose of 3 or more courses of IPTc was slightly higher in the community based arm (90.5% vs 86.6%; p = 0.059). Completion of the three dose regimen was high and similar with both delivery systems (91.6% and 91.7% respectively).Seasonal IPTc delivered through community-based or facility-based systems can achieve a high coverage rate with the support and supervision of the district health management team. However, in order to maximise the impact of IPTc, both delivery systems may be needed in some settings.ClinicalTrials.gov NCT00119132