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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

An analysis of intelligent failure within corporate entrepreneurship

Casely, William Robert January 2016 (has links)
Intelligent failure occurs when an entrepreneurial initiative falls short of its anticipated performance. It provides valuable new knowledge to the organisation and is recognised as an important factor in long-term corporate entrepreneurial success. This thesis is located within the domain of corporate entrepreneurship and entrepreneurial failure, and explores the various processes of intelligent failure. The specific aim of this thesis is to learn how organisations manage intelligent failure. Research takes an inductive approach with the predominant use of a qualitative methodology and, as part of a multiple case study strategy, research is carried out in six organisations operating in differing sectors within the UK. Findings indicate that the organisations often fail to manage intelligent failure. There is little evidence of a strategic approach to learning from failure and, where learning occurs, it is predominantly unstructured. This is significant because literature consistently argues that a structured process is required to manage learning from failure successfully. This research recognises that structured processes may be more effective than unstructured processes when looked at in isolation. However, this thesis argues that unstructured mechanisms do have inherent value. Therefore, when organisations develop failure management processes, a dual path may be considered, which might extract value from both systems as is contextually appropriate. This may enable organisations to maximise their ability to learn from failure. This thesis adds to existing management theory in the corporate entrepreneurship domain. In specifically focusing on the structured and unstructured forms within the process of intelligent failure, this thesis addresses a gap in current literature. It also adds to existing literature that centres on the practical management of the learning from failure process.
122

Gas induced rupture of elastomers

Liatsis, Dimitrios January 1989 (has links)
No description available.
123

Fibre-cement hybrid composites

Guodong, Xu January 1994 (has links)
The theoretical stress-strain behaviour of individual fibre reinforced cement composites is reviewed. Based on the multiple cracking concept of the existing theory, analytical expressions are developed to describe the tensile stress-strain behaviour of a fibre-cement hybrid composite consisting of three components, i.e. two reinforcing fibres with different moduli, strengths and strains to failure and a common cement binder. The model predicts that the tensile stress-strain curve of the hybrid composites consists of five stages, instead of three stages of the existing models for individual fibre cements, and relates the tensile behaviour of each stage to the component properties of the components and the test system parameters. A description is given of the physical and mechanical properties of four types of reinforcing fibres used in the study. These were fibrillated polypropylene film, alkali-resistant glass, polyvinyl alcohol fibres and carbon fibres. A small number of direct tensile tests on continuous glass, carbon and polyvinyl alcohol were performed. The tensile stress-strain behaviour of four types of fibre-cement hybrid composites was studied with particular emphasis on that of the glass- polypropylene hybrids for which the flexural load-deflection behaviour was also examined. It is shown that the fibre-cement hybrid composites yield superior engineering properties over their parent composites and the improvements are sensitive to volume fractions of each of the two fibres. The measured tensile stress-strain curves of the hybrids were compared with the theoretical predictions and satisfactory agreement in general is obtained. Implications from the present work for the design of fibre-cement hybrid composites are assessed.
124

Failure Analysis of Modular Hip Implant

Shah, Nishi 01 December 2012 (has links)
Biomaterials is a systematically, pharmacologically inert substance designed for implantation within or incorporation with a living system. The ultimate goal of biomaterials is to restore function of living tissues and organs of the body. Chemical stability, mechanical behavior and biocompatibility in body fluids and tissues are basic requirements for successful application of implant materials in hip replacements. The field of biomaterials has become a vital area, as these materials can enhance the quality and longevity of human life and the science and technology associated with this field has now led to multi-million dollar business. The thesis focuses mainly on fractured analysis of retrieved titanium-alloy modular hip implants, even though there exists biomaterials made up of ceramics, polymers and composite materials As it is well known that a good biomaterial should possess the fundamental properties such as better mechanical and biological compatibility and enhanced wear and corrosion resistance in biological environment. The primary purpose of this thesis was to identify the reasons which lead to fracture of implant retrieved from 60years old male implanted for a 16 month time. The retrieved Implant was sterilized for two hours to overcome bio hazardous condition. The fractured area of implant sleeve and stem was cut with help of machine ISOMET BUEHLER 4000 consisting of diamond saw. The cut sample was placed into physiological solution (0.9% NaCl in H2O), and was maintained at room temperature over night. Samples were then thoroughly brushed with help of toothpaste and tooth brush to get rid of tissue deposits and blood stains so as to get clear picture under SEM. Fractures sample was than observed under Scanning Electron Microscope and a detailed study revealed fretting corrosion and fatigue failure were main cause of implant failure. After examining under SEM, sample was than prepared to be polished by covering it with epoxy and using BUEHLER polishing machine and sand paper from 240-1200 grid and finally a micro cloth to smoothen the surface. After sample being polished, it was immersed in Kroll solution for etching and observing under microscope to figure micro-structural changes.
125

Delamination in composite laminates with curvature and discontinuous plies

Petrossian, Zackarias January 1998 (has links)
No description available.
126

Osteoarthritis of the hand

Lim, Keith K. T. January 1997 (has links)
No description available.
127

Failure mechanisms in MOS devices

Amerasekera, Ekanayake A. January 1986 (has links)
Continuous and pulsed voltage stressmg of metal oxide semiconductor (MOS) transistors and capacitors has been mvestigated. The expenmental work followed a survey of failure mechanisms in semiconductor devices which Identified Electrical Overstress Damage (EOS)/Electrostatic Discharge (ESD) damage as the most frequent cause of failure, accounting for over 50% of all damage observed. The survey itself, covered all aspects of semiconductor reliability including reliability modelling and quality assurance. A qualitative model of oxide breakdown in MOS structures was developed as a result of the experimental work. Two different mechanisms have been proposed for continuous and pulsed voltage breakdown. Continuous voltage breakdown simulating EOS conditions, was temperature and voltage dependent. The long time-scales involved, lead to a model whereby breakdown IS the result of conduction of charge earners through the oxide, via electron traps and impunty Sites with energies m the forbidden gap. Pulsed voltage breakdown simulating ESD, was voltage dependent but not temperature dependent. The very short time-scales involved indicate that breakdown is the direct result of electron transport m the oxide conduction band. Electrons are inJected into the conduction band via quantum-mecharucal tunnelling from the cathode. Both mechanisms were found to be dependent on the surface charge concentratiOn of the Silicon and, therefore, polanty dependent. The models explain this effect by analysing the charge injection process under high electric fields.
128

Elastic properties and failure mechanisms in hybrid composites with differing resin matrices

Heumann, Timothy O. January 1987 (has links)
Previous work on tensile and compressive failure of both monofibre and hybrid unidirectional composites is reviewed, together with a summary of some of the more important works on the variation of elastic modulus.
129

Detection of an oxidising molecule in uraemic plasma using electron spin resonance spectroscopy, preliminary chemical characterisation and clinical evaluation

Roselaar, Simon Edwin January 1994 (has links)
No description available.
130

Mechanical properties of a solid oxide fuel cell electrolyte

Lowrie, Fiona Louise January 1996 (has links)
No description available.

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