220,594 research outputs found

    Fatigue/fracture mechanics analysis of threaded tether connections

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    The use of threaded connections for joining tubes and pipes is widespread within the oil and gas drilling industry. Such connections have more recently been employed for the joining of tethering elements for a new generation of offshore platform, the Tension Leg Platform (TLP). The platform design depends totally on the integrity of the tethering system and the threaded connection between tether elements has been identified as a critical structural component. The hostile environment of the North Sea leads to severe cyclic loading on the tethering system and fatigue is the most likely in-service damage mechanism. This study involves an analysis of the fatigue behaviour of large threaded connections of the type proposed for tethering applications and considers the implications for subsequent in-service inspection and integrity assessment. A simplified model for the prediction of the non-uniform load distribution within the connection is proposed and this is validated using finite element (FE) modelling of a complete connection. A methodology for the use of this model, in conjunction with simple FE sub models, for the prediction of dynamic stresses in preloaded and unpreloaded connections is presented. Fatigue initiation and fracture mechanics based crack growth models are proposed for this application and large scale tests, to provide experimental data for validation of these models, have been conducted. An inspection system was developed to enable fatigue crack growth to be measured during the test. It is likely that this system will be suitable for integrity monitoring of large scale threaded connections removed from service. The requirements for integrity monitoring during service, based on a knowledge of the likely fatigue behaviour, are considered for a tethering system and a methodology for defining service inspection intervals as discussed

    Knowledge Representation Concepts for Automated SLA Management

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    Outsourcing of complex IT infrastructure to IT service providers has increased substantially during the past years. IT service providers must be able to fulfil their service-quality commitments based upon predefined Service Level Agreements (SLAs) with the service customer. They need to manage, execute and maintain thousands of SLAs for different customers and different types of services, which needs new levels of flexibility and automation not available with the current technology. The complexity of contractual logic in SLAs requires new forms of knowledge representation to automatically draw inferences and execute contractual agreements. A logic-based approach provides several advantages including automated rule chaining allowing for compact knowledge representation as well as flexibility to adapt to rapidly changing business requirements. We suggest adequate logical formalisms for representation and enforcement of SLA rules and describe a proof-of-concept implementation. The article describes selected formalisms of the ContractLog KR and their adequacy for automated SLA management and presents results of experiments to demonstrate flexibility and scalability of the approach.Comment: Paschke, A. and Bichler, M.: Knowledge Representation Concepts for Automated SLA Management, Int. Journal of Decision Support Systems (DSS), submitted 19th March 200

    Improve safety by reducing the impact of external corrosion on pipelines

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    • Proactive prevention of corrosion defects from growing to a size that ultimately impacts a pipeline’s structural integrity • Continuous assessment to identify & address where corrosion has occurred, is occurring or may occur • Repairing corrosion defects • Correcting the causes of corrosio

    Doing Good Today and Better Tomorrow: A Roadmap to High Impact Philanthropy Through Outcome-Focused Grantmaking

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    Describes Hewlett's experience with implementing the outcome-focused grantmaking (OFG) process in its environment program as a guide for identifying a portfolio of grants with maximum impact. Outlines trials and errors, recent innovations, and challenges

    HACCP based quality assurance systems for organic food production systems

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    HACCP provides an effective, logical and structured means of assuring food safety. Although first used in food manufacturing operations, HACCP can be – and, increasingly is – applied to food production and handling operations at all stages in the food chain. This includes the primary production sector. The purpose of this paper is to illustrate how the principles of HACCP can be applied to organic production with special reference to the primary sector

    CHORUS Deliverable 3.4: Vision Document

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    The goal of the CHORUS Vision Document is to create a high level vision on audio-visual search engines in order to give guidance to the future R&D work in this area and to highlight trends and challenges in this domain. The vision of CHORUS is strongly connected to the CHORUS Roadmap Document (D2.3). A concise document integrating the outcomes of the two deliverables will be prepared for the end of the project (NEM Summit)
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