Thesis (M.S.) -- Mississippi State University. Department of Civil Engineering. / Title from title screen. Includes bibliographical references.

The Royal Fleet Auxiliary (RFA) is a flotilla of ships, owned by the United Kingdom (UK) Ministry of Defence (MoD), which serves to resupply naval vessels during worldwide operations. Design Alterations and Additions (As&As) are implemented throughout their service lives in order to ‘Upgrade’ and ‘Update’ their capability. This research offers an original contribution to knowledge by applying formal decision making techniques to A&A reasoning in a way that, to the best knowledge of the researcher, has not previously been implemented as an integral part of the in-service design control process for RFA ships. In delivering this contribution, Multi Attribute Decision Making (MADM) techniques are investigated and applied. Three MADM techniques are applied: SAW (Simple Additive Weighting), AHP (Analytic Hierarchy Processes) and TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution). Application of these techniques defines the scope boundary and so rules out exhaustive investigation into the wider decision making approaches that could form the focus of future research. Literature reviews indicate that formal decision techniques have been extensively studied and applied – seemingly to the point of saturation. For this reason, the research does not claim to have developed new techniques. Rather, the contribution to knowledge lies in the systematic application of the techniques. In this respect, a niche topic is identified involving the implementation of As&As during Fleet Time (FT). Investigation results in the systematic identification and categorisation of the Risk Factors (RFs) constraining FT implementation. Two different techniques (SAW and AHP) are applied to FT As&As. The outcomes demonstrate a consistent trend and so offer mutual assurance. In addition, comparison of the techniques indicates that, whilst SAW offers a convenient and intuitive approach, the AHP imposes a higher cognitive burden. This is regarded as significant by the researcher since As&As are subject to schedule and cost constraints, whereby pragmatic and proportional approaches are more likely to find programme acceptance. Based upon an actual decision involving the selection of materials for a ship sea water system, TOPSIS is used to evaluate the options against key criteria. A sensitivity analysis indicates that selection will be influenced in the direction of the criteria weighting. Since ‘procurement cost’ is an important criterion for As&As, the thesis demonstrates a methodology for the delivery of robust cost estimates. This involves the treatment of cost uncertainty using risk analysis software based upon the Monte Carlo technique. The researcher consolidates studies into systematic decision methodologies for As&As. Credibility is claimed since methodologies are based upon established techniques and tested against A&A examples. Credibility is also claimed from the theme, running throughout the thesis, that the studies build upon the professional experience of the researcher and involve engagement with Suitably Qualified and Experienced Personnel (SQEP).

This work presents an investigation into the production of components for in-situ oceanographic nutrient sensors. These devices are based on a micro fluidic chip platform, taking the lab-on-a-chip (LOC) system concept out of the laboratory and into a real world environment. The systems are designed to provide data on nutrient concentrations in the ocean and as such are built from robust low cost materials designed for deployments from 24 hours to 3 months. This report focuses on the challenges faced in designing a micro fluidic system for these harsh deployment situations including a study of the relevant literature to indicate short falls in current technologies. The aim of this work was to develop the next generation of micro fluidic chip based nutrient sensors. A novel solvent vapour bonding technique has been developed for the production of polymer based micro fluidic chips which produces robust chips while simultaneously reducing the surface roughness of the substrates during bonding. This has allowed micromilling of polymer substrates to quickly and easily develop new chip designs with optical quality features. The surface reduction technology has enabled development of a method to integrate absorbance cells into tinted PMMA devices which is also discussed. Integration of polymer membranes to produce valve and pump structures is discussed and a novel bonding technique for chemically robust Viton R membranes is demonstrated. The final chapter includes a discussion on system topologies, concentrating on the need for high resolution sampling and the implications on system design that arise. A novel multiplexed stop ow system is demonstrated. Questions about the role of traditional micro fluidic components, such as mixers, in high-throughput low temporal response system designs are discussed and a micro fluidic mixer suitable for some of these systems demonstrated.

Understanding soft cliff systems is a significant challenge owing to the complex recession process and the need to quantify future responses to climate change. Process-based geomorphic modelling provides a key method for developing our understanding. However, existing models are frequently criticised for their simplified treatment of the cliff. Therefore, the overriding aim of this research was to contribute towards the development of a more integrated model. To facilitate this, this research has applied, evaluated and refined the SCAPE (Soft Cliff and Platform Erosion) model to a study frontage of variable lithology and coastal planshape on the south west coast of the Isle of Wight (UK). The initial model appraisal highlighted the need to further understand and quantify the role of variable material strength on shore platform geomorphology and rates of cliff toe retreat. The model was subsequently refined and demonstrated that outcropping layers of variable material resistance about mean sea level are a key control on the rates of cliff erosion, particularly for low sediment frontages. Weaker layers were found to result in an asymmetric increase in retreat in comparison to a more resistant layer of the same characteristics owing to the contrasting effects on the shore platform slope. This emphasises the importance of not extrapolating historic rates of retreat across frontages of variable lithology. Coastal management studies must consider relative changes in material resistance up the cliff face, the thickness of variable layers and the rate of sea-level rise to determine the magnitude of impact and duration of exposure.

This work is concerned with the damage tolerance assessment of laminated composite structures used in ship structures. An intensive review has been carried out with regard to current experimental, analytical and numerical work on both laminates and structural elements. Particular attention has been focused on the problem of damage due to delamination and its structural consequences. Strength assessments of top hat stiffeners and tee joints has been carried out with a view to identifying regions most susceptible to delaminations. It has been shown that such regions are contained within the curved region of the overlaminate in both types of structural elements. Strain energy release rates and J-integral values have been calculated for specific cracks to determine their likelihood of propagation under a variety of loading conditions. Overall, a number of conclusions have been drawn with regard to single-skin marine FRP structures. For example, both the strength - and the energy - based approaches have predicted that a tee joint subjected to a 45 degree pull-off load, delaminations which are deep within the overlaminate are more likely to propagate than those close to the surface.

Hydraulic conductivity is a measurement of the ease of movement of a fluid through a medium and is therefore a key parameter in the design of landfill leachate management systems. Hydraulic conductivity of landfilled wastes may be affected by several factors such as overburden stress from the weight of overlying waste, water content, the type, age and pre-processing of the waste, and the presence of landfill gas. A further factor that may affect leachate movement through wastes is the predominantly horizontal orientated structure of compacted wastes. This anisotropic structure may result in hydraulic conductivity in the horizontal direction being greater than that in the vertical direction. However existing research has been effectively limited to evaluating hydraulic conductivity in a single plane and so the presence of anisotropic flow in waste remains unproven. Consequently, modelling of leachate and contaminant movement in landfills may be compromised by the use of isotropic, or assumed anisotropic, hydraulic conductivity values. The object of this research has been to assess for the first time the inherent anisotropy of two different waste samples by measuring and comparing the vertical and horizontal hydraulic conductivities over a range of stresses typical of landfill conditions. In this thesis, factors affecting the measurement of hydraulic conductivity of wastes are discussed, and details of the samples tested and test methodology are given. The results of the tests are shown and alternative test methods are discussed. The effects of gas accumulation and pore water pressure on waste hydraulic conductivity encountered during testing are also reported as further research has developed from this important finding.

Oil terminals are complex infrastructures due to their diverse operational activities. They are exposed to diverse risks because they usually operate in a dynamic environment in which safety barriers are sometime overwhelmed, leading to the disruption of operations due to a high level of uncertainty. However, the ability of oil terminals to minimise vulnerability and maximise resilience depends on the availability of the correct anticipated information at the right time for a decision-making process. An important finding from the reviewed literature revealed that uncertainties and the unpredictability of the convergent effect of several hazardous factors have the potential to cause major disruptions such as fire, explosion and transit accidents. The consequences of these disruptions can lead to infrastructure damage and loss of life. The common operational threats to oil terminal operations (OTOs) substantiates the need for a holistic resilience model for operations in offshore/onshore terminals such as berthing/unberthing, vessel manoeuvring, loading and offloading, storage, etc. Due to the uncertainties associated with these operations and the cases of reported incidents/accidents, this research focuses more on the aspect of loading and offloading operations at ship/terminal interface. An emphasis on a resilience modelling approach provides a flexible yet robust model for OTOs to address disruption proactively, particularly with constantly evolving hazards and threats. This thesis introduces an innovative approach towards resilience modelling based on a developed novel framework. The key aspect of the framework was supported using three proposed models: (1) the integration of Utility Theory and Swiss Cheese Model (UtiSch_+), to evaluate the relative importance of the identified hazard factors (HFs), (2) a Bayesian network (BN), to calculate the overall probability that a specific hazard is present and, (3) an Analytical Hierarchical Process (AHP) - Prospect Theory (PT) approach, as an important model for a strategic decision selection method. An empirical study was conducted to test the validity the proposed models, using case studies and Sensitivity Analysis (SA). The result obtained demonstrated that the models are effective techniques to obtain the relative weight of the identified Hazard Factors (HFs) in order to prioritise them, for dynamic hazards probability evaluation and to prioritise suggested resilience strategies in order of importance to mitigate hazard/risk level. Evidently, the result revealed appears reasonable and appropriate for investment, in order to support a strategic decision for the selection of a resilience strategy for resilience improvement in OTOs.

Container supply chains are vulnerable to many risks. Vulnerability can be defined as an exposure to serious disturbances arising from the risks within the supply chain as well as the risks external to the supply chain. Vulnerability can also be defined as exposure to serious disturbances arising from a hazard or a threat. Containers are one of the major sources of security concerns and have been used, for example, to smuggle illegal immigrants, weapons, and drugs. The consequences of the use of a weapon of mass destruction or discovery of such a device in a container are serious. Estimates suggest that a weapon of mass destruction explosion and the resulting port closure could cost billions of dollars. The annual cost of container losses as consequences of serious disturbances arising from hazards is estimated as $500 million per year. The literature review, historical failure data, and statistical analysis in the context of containerships' accidents from a safety point of view clearly indicate that the container cargo damage, machinery failure, collision, grounding, fire/explosion, and contact are the most significant accident categories with high percentages of occurrences. Another important finding from the literature review is that the most significant basic event contributing to the supply chains' vulnerability is human error. Therefore, firstly, this research makes full use of the Evidential Reasoning (ER) advantages and further develops and extends the Fuzzy Evidential Reasoning (FER) by exploiting a conceptual and sound methodology for the assessment of a seafarer's reliability. Accordingly, control options to enhance seafarers' reliability are suggested. The proposed methodology enables and facilitates the decision makers to measure the reliability of a seafarer before his/her designation to any activities and during his/her seafaring period. Secondly, this research makes full use of the Bayesian Networks (BNs) advantages and further develops and extends the Fuzzy Bayesian Networks (FBNs) and a "symmetric method" by exploiting a conceptual and sound methodology for the assessment of human reliability. Furthermore a FBN model (i. e. dependency network), which is capable of illustrating the dependency among the variables, is constructed. By exploiting the proposed FBN model, a general equation for the reduction of human reliability attributable to a person's continuous hours of wakefulness, acute sleep loss and cumulative sleep debt is formulated and tested. A container supply chain includes dozens of stakeholders who can physically come into contact with containers and their contents and are potentially related with the container trade and transportation. Security-based disruptions can occur at various points along the supply chain. Experience has shown that a limited percentage of inspection, coupled with a targeted approach based on risk analysis, can provide an acceptable security level. Thus, in order not to hamper the logistics process in an intolerable manner, the number of physical checks should be chosen cautiously. Thirdly, a conceptual and sound methodology (i. e. FBN model) for evaluating a container's security score, based on the importer security filling, shipping documents, ocean or sea carriers' reliability, and the security scores of various commercial operators and premises, is developed. Accordingly, control options to avoid unnecessary delays and security scanning are suggested. Finally, a decision making model for assessing the security level of a port associated with ship/port interface and based on the security score of the ship's cargo containers, is developed. It is further suggested that regardless of scanning all import cargo containers, one realistic way to secure the supply chain, due to lack of information and number of variables, is to enhance the ocean or sea carriers' reliability through enhancing their ship staff's reliability. Accordingly a decision making model to analyse the cost and benefit (i.e. CBA) is developed.

No description available.

This research aims to propose a Risk Management (RM) framework and develop a generic risk-based model for dealing with potential hazards and risk factors associated with offshore terminals' and marine ports' operations and management. Hazard identification was conducted through an appropriate literature review of major risk factors of these logistic infrastructures. As a result in the first phase of this research a Fuzzy Analytical Hierarchal Process (FAHP) method was used for determining the relative weights of the risk factors identified via the literature review. This has led to the development of a generic risk -based model which can help related industrial professionals and risk managers assess the risk factors and develop appropriate strategies to take preventive/corrective actions for mitigation purposes, with a view of maintaining efficient offshore terminals' and marine ports' operations and management. In the second phase of the research the developed risk-based model incorporating Fuzzy Set Theory (FST), an Evidential Reasoning (ER) approach and the IDS software were used to evaluate the risk levels of different ports in real situations using a case study. The IDS software based on an ER approach was used to aggregate the previously determined relative weights of the risk factors with the new evaluation results of risk levels for the real ports. The third phase of the research made use of the Cause and Consequence Analysis (CCA) including the Fault Tree Analysis (FTA) and Event Tree Analysis (ETA) under a fuzzy environment, to analyse in detail the most significant risk factors determined from the first phase of the research, using appropriate case-studies. In the fourth phase of the research an individual RM strategy was tailored and implemented on the most significant risk factor identified previously. In the last phase of the research and in order to complete the RM cycle, the best mitigation strategies were introduced and evaluated in the form of ideal solutions for mitigating the identified risk factors. All methods used in this research have quantitative and qualitative nature. Expert judgements carried out for gathering the required information accounted for the majority of data collected. The proposed RM framework can be a useful method for managers and auditors when conducting their RM programmes in the offshore and marine industries. The novelty of this research can help the Quality, Health, Safety, Environment and Security (QHSES) managers, insurers and risk managers in the offshore and marine industries investigate the potential hazards more appropriately if there is uncertainty of data sources. In this research with considering strategic management approaches to RM development the proposed RM framework and risk based model contribute to knowledge by developing and evaluating an effective methodology for future use of the RM professionals.