Axisymmetric shell structures for multi-use

Shell structures find use in many fields of engineering, notably structural, mechanical, aerospace and nuclear-reactor disciplines. Axisymmetric shell structures are used as dome type of roofs, hyperbolic cooling towers, silos for storage of grain, oil and industrial chemicals and water tanks. Despite their thin walls, strength is derived due to the curvature. The generally high strength-to-weight ratio of the shell form, combined with its inherent stiffness, has formed the basis of this vast application. With the advent in computation technology, the finite element method and optimisation techniques, structural engineers have extremely versatile tools for the optimum design of such structures. Optimisation of shell structures can result not only in improved designs, but also in a large saving of material. The finite element method being a general numerical procedure that could be used to treat any shell problem to any desired degree of accuracy, requires several runs in order to obtain a complete picture of the effect of one parameter on the shell structure. This redesign I re-analysis cycle has been achieved via structural optimisation in the present research, and MSC/NASTRAN (a commercially available finite element code) has been used in this context for volume optimisation of axisymmetric shell structures under axisymmetric and non-axisymmetric loading conditions. The parametric study of different axisymmetric shell structures has revealed that the hyperbolic shape is the most economical solution of shells of revolution. To establish this, axisymmetric loading; self-weight and hydrostatic pressure, and non-axisymmetric loading; wind pressure and earthquake dynamic forces have been modelled on graphical pre and post processor (PATRAN) and analysis has been performed on two finite element codes (ABAQUS and NASTRAN), numerical model verification studies are performed, and optimum material volume required in the walls of cylindrical, conical, parabolic and hyperbolic forms of axisymmetric shell structures are evaluated and reviewed. Free vibration and transient earthquake analysis of hyperbolic shells have been performed once it was established that hyperbolic shape is the most economical under all possible loading conditions. Effect of important parameters of hyperbolic shell structures; shell wall thickness, height and curvature, have been evaluated and empirical relationships have been developed to estimate an approximate value of the lowest (first) natural frequency of vibration. The outcome of this thesis has been the generation of new research information on performance characteristics of axisymmetric shell structures that will facilitate improved designs of shells with better choice of shapes and enhanced levels of economy and performance. Key words; Axisymmetric shell structures, Finite element analysis, Volume Optimisation_ Free vibration_ Transient response.

Israel's airstrike on Syria's Al-Kibar facility : a test case for the doctrine of pre-emptive self-defence?

This article analyses the legality of Israel’s 2007 airstrike on an alleged Syrian nuclear facility at Al-Kibar—an incident that has been largely overlooked by international lawyers to date. The absence of a threat of imminent attack from Syria means Israel’s military action was not a lawful exercise of anticipatory self-defence. Yet, despite Israel’s clear violation of the prohibition on the use of force there was remarkably little condemnation from other states, suggesting the possibility of growing international support for the doctrine of pre-emptive self-defence. This article argues that the muted international reaction to Israel’s pre-emptive action was the result of political factors, and should not be seen as endorsement of the legality of the airstrike. As such, a lack of opinio juris means the Al-Kibar episode cannot be viewed as extending the scope of the customary international law right of self-defence so as to permit the use of force against non-imminent threats. However, two features of this incident—namely, Israel’s failure to offer any legal justification for its airstrike, and the international community’s apparent lack of concern over legality—are also evident in other recent uses of force in the ‘war on terror’ context. These developments may indicate a shift in state practice involving a downgrading of the role of international law in discussions of the use of force. This may signal a declining perception of the legitimacy of the jus ad bellum, at least in cases involving minor uses of force.

Managing identity transitions during radical change in nuclear engineering organizations

This study reports the construction and reconstruction of identities of new and existing employees during a significant transition phase of a nuclear engineering organization. We followed a group of new and existing employees over the period of three years, during which the organization constructed a greenfield nuclear facility with new generational technologies whilst in parallel, decommissioned the older reactor. This change led to the transfer and integration of existing trade-based employees with the newly recruited, primarily university educated graduates in the new site. Three waves of interview data were collected, in conjunction with the cognitive mapping of social grouping and photo elicitation portrayed the stories of different group of employees who either succeeded or failed at embracing their new professional identity. In contrast with the new recruits who constructed new identities as they join this organization, we identify and report on the number of enabling and disabling factors that influence the process of professional identity construction and reconstruction during gamma change.

Rethinking copyrights for the library through Creative Commons licensing

Two recent and related social developments of note for libraries are an upsurge in cultural participation enabled by Web 2.0 media and calls in government policy for enhanced innovation through education. Ironically, these have occurred at the same time that increasingly stringent copyright laws have restricted access to cultural content. Concepts of governmentality are used here to examine these tensions and contradictions. In particular, Foucault’s critique of the author figure and of freedom as part of the will to govern within liberal democratic societies is used to argue for better quality copyright education programs in school libraries and library information science education programs. For purposes of teaching and research, copyrights are defined as agglomerations of legal, economic, and educational discourses that enable and constrain what can and cannot be done with text in homes, schools, and library media centers. The article presents some possibilities for renewal of school libraries around copyright education and Creative Commons licensing.

A database ATP simulated waveforms of shunt reactor switching cases with vacuum breakers on motor circuits

This paper presents a database ATP (Alternative Transient Program) simulated waveforms for shunt reactor switching cases with vacuum breakers in motor circuits following interruption of the starting current. The targeted objective is to provide multiple reignition simulated data for diagnostic and prognostic algorithms development, but also to help ATP users with practical study cases and component data compilation for shunt reactor switching. This method can be easily applied with different data for the different dielectric curves of circuit-breakers and networks. This paper presents design details, discusses some of the available cases and the advantages of such simulated data.

Driving and licensing experiences of learner drivers in two Australian states prior to major changes in the licensing laws

The learner licence is an important component of the graduated driver licensing system. This research describes the driving and licensing experiences of learner drivers in Queensland and New South Wales licensed prior to the changes made to the system in mid-2007. The sample consisted of 392 participants who completed a telephone interview just after they obtained their provisional licence. The results suggest that learner drivers in the two states had many similar experiences when they were obtaining a learner licence. However, once a learner licence was obtained, there were differences in the amount of practice, the supervisor learners practised with, the type of vehicle they used and the amount of unlicensed driving. This paper provides important baseline descriptive data that can be used to measure the impact of the changes that were introduced to the learner licence phase in mid-2007 in both of these states.

Open access policies, practices and licensing : a review of the literature in Australia and selected jurisdictions

The full economic, cultural and environmental value of information produced or funded by the public sector can be realised through enabling greater access to and reuse of the information. To do this effectively it is necessary to describe and implement a policy framework that supports greater access and reuse among a distributed, online network of information suppliers and users. The objective of this study was to identify materials dealing with policies, principles and practices relating to information access and reuse in Australia and in other key jurisdictions internationally. Open Access Policies, Practices and Licensing: A review of the literature in Australia and selected jurisdictions sets out the findings of an extensive review of published materials dealing with policies, practices and legal issues relating to information access and reuse, with a particular focus on materials generated, held or funded by public sector bodies. The report was produced as part of the work program of the project “Enabling Real-Time Information Access in Both Urban and Regional Areas”, established within the Cooperative Research Centre for Spatial Information (CRCSI).

Enhancing road safety for young drivers : how Graduate Driver Licensing initiatives can complement "anti-hooning" legislation

Street racing and associated (hooning) behaviours have attracted increasing concern in recent years. While New Zealand and all Australian jurisdictions have introduced “antihooning” legislation and allocated significant police resources to managing the problem, there is limited evidence of the road safety implications of hooning. However, international and Australian data suggests that drivers charged with a hooning offence tend to be young males who are accompanied by one or more peers, and hooning-related crashes tend to occur at night. In this regard, there is considerable evidence that drivers under the age of 25 are over-represented in crash statistics, and are particularly vulnerable soon after obtaining a Provisional licence, when driving at night, and when carrying peer-aged passengers. The similarity between the nature of hooning offenders, offences and crashes, and road safety risks for young drivers in general, suggests that hooning is an issue that may be viewed as part of the broader young driver problem. Many jurisdictions have recently implemented a range of evidence-based strategies to address young driver road safety, and this paper will present Queensland crash and offence data to highlight the potential benefit of Graduated Driver Licensing initiatives, such as night driving restrictions and peer-aged passenger restrictions, to related road safety issues, including hooning. An understanding of potential flow-on effects is important for evaluations of anti-hooning legislation and Graduated Driver Licensing programs, and may have implications for future law enforcement resource allocation and policy development.

Mobility and safety are conflicting goals for transport policy makers when making decisions about graduated driver licensing

Policy decisions are frequently influenced by more than research results alone. This review examines one road safety countermeasure, graduated driver licensing, in three jurisdictions and identifies how the conflict between mobility and safety goals can influence policy decisions relating to this countermeasure. Evaluations from around the world of graduated driver licensing have demonstrated clear reductions in crashes for young drivers. However, the introduction of this countermeasure may be affected, both positively and negatively, by the conflict some policy makers experience between ensuring individuals remain both mobile and safe as drivers. This review highlights how this conflict in policy decision making can serve to either facilitate or hinder the introduction of graduated driver licensing systems. However, policy makers whose focus on mobility is too strong when compared with safety may be mistaken, with evidence suggesting that after a graduated driver licensing system is introduced young drivers adapt their behaviour to the new system and remain mobile. As a result, policy makers should consciously acknowledge the conflict between mobility and safety and consider an appropriate balance in order to introduce these systems. Improvements to the licensing system can then be made in an incremental manner as the balance between these two priorities change. Policy makers can achieve an appropriate balance by using empirical evidence as a basis for their decisions.

Licensing technology : negotiating and drafting technology transfer agreements [3rd ed.]

Part I of this book covers the commercial and contractual background to technology licensing agreements. Part II discusses the European Community's new regime on the application and enforcement of Article 81 to technology licensing agreements. EC Council Regulation 1/2003 replaced the Council Regulation 17/1962 and repealed the system under which restrictive agreements and practices could be notified to the EC Commission. A new Commission regulation on technology transfer agreements, Regulation 772/2004. These two enactments required consequential amendments to the chapters in Part III where the usual terms of technology licensing agreements are analysed and exemplified by reference to decided cases.

The use of Creative Commons licensing to enable open access to public sector information and publicly funded research results : an overview of recent Australian developments

This chapter provides an account of the use of Creative Commons (CC) licensing as a legally and operationally effective means by which governments can implement systems to enable open access to and reuse of their public sector information (PSI). It describes the experience of governments in Australia in applying CC licences to PSI in a context where a vast range of material and information produced, collected, commissioned of funded by government is subject to copyright. By applying CC licences, governments can give effect to their open access policies and create a public domain of PSI which is available for resue by other governmental agencies and the community at large.