Diffuse sources of sediment may have important implications for flood risk management (FRM), especially as catchment sediment yields are predicted to increase in future. UK legislation requires FRM to work with natural processes wherever possible, including accounting for sediments. However, the importance of wash-material load to FRM has been under researched and both a robust evidence-base and practical sediment models are needed to identify, prioritise and justify sediment-related catchment management. Research addressing these issues was centred on the River Tone, a sub-catchment of the Parrett, in which features excessive inputs of sediment in its upper catchment combined with high potential for deposition in its lower reaches. Links between sediment sources, water and sediment runoff, and downstream sediment sinks were established and the research examined the role played by sediment, especially wash-material load, within the fluvial system. The greatest sediment-related threats to the functioning of this lowland river stem from either: a protracted, major reduction in wash-material load; or a significant increase in bed-material load. Imbalance in the Tone fluvial-sediment system may not significantly affect flood risk directly, but has implications for FRM operations, maintenance and monitoring. Impacts on land quality result from soil loss. For example, ~2.5 million tonnes of soil has been eroded from the Parrett catchment since WWII. Water quality issues include delivery of phosphate and other pollutants into the river, and potentially more frequent dredging that remobilises contaminants. The thesis defines the key sediment-related components of sustainable, integrated catchment management and provides an improved evidence-base upon which to engage stakeholders. It tests and benchmarks sediment assessment tools including the Sediment Impact Assessment Model (SIAM). An approach to catchment-scale sediment assessment for lowland rivers is recommended, which involves a nested-approach using routinely collected and project-specific field data, stream power screening and SIAM.

A novel configuration of vertical downflow constructed wetland was used to treat up to 75 m3 per day of sugar beet processing wastewaters. The 403 m2, two-stage pilot system included planted and unplanted cells of a variety of sand depths (0.15 - 0.4 m) and sand particle size distributions (d10 = 0.07 - 1.2 mm). The hydraulic regime of each bed was also manipulated. Typical beet processing wastewaters contained 235 mg BOD l-1, 45 mg NH4-N l-1, 0.03 mg PO4-P l-1, 16 mg TSS l-1, at pH 8.2 and 29 °C. Overall performance of the pilot system, with respect to BOD, NH4-N, and TSS removal, was similar to, or better than, comparable two-stage vertical flow wetland systems. In vertical flow systems, influent BOD concentrations >600 mg l-1 were coincident with reduced rates of nitrification. Mean BOD removal rate in the pilot system was 38.8 g BOD m-2 d-1, with a mean loading rate of 40.4 g BOD m-2 d-1. The first-order reaction rate for BOD removal was calculated to be 0.369 m d-1 over the whole system. High rates of oxygen transfer and efficient removal of organic solids were seen as the most important factors enhancing BOD removal. Mean NH4-N removal rate in the pilot system was 5.6 g NH4-N m-2 d-1, with a mean loading rate of 7.3 g NH4-N m-2 d-1. The temperature corrected first-order reaction rate for NH4-N removal was calculated to be 0.23 m d-1 over the whole system. Nitrification accounted for between 85% and 99% of TKN removal. Evidence is presented which supports the hypothesis that cycles of assimilation/adsorption and release of NH4-N may play an important role in nitrification mechanisms in vertical flow constructed wetlands. In bed 1, removal of BOD and NH4-N were at their most efficient in the vegetated cell with the deepest (0.21 m), coarsest (d10 = 1.2 mm) sand layer. TSS removal was highest in an unvegetated cell with shallower (0.15 m), finer (d10 = 0.56 mm) sand. In bed 2, removal of BOD, NH4-N, and TSS were all at there most efficient in the vegetated cell with the deepest (0.4 m), coarsest (d10 = 0.1 mm) sand layer. Low influent phosphate concentrations may have limited nitrification rates in the pilot system. The surface area available for biofilm attachment, and media depth, both provided good models of NH4-N removal, whilst cell surface area was more important in solids removal. Media hydraulic conductivity at the beginning of the dosing cycle was five times higher in vegetated cells than in unvegetated cells. After 12 hours of dosing, media particle size distribution became the dominant factor determining media hydraulic conductivity. High influent BOD concentration was more closely associated with cell logging than hydraulic loading, TSS concentration, or BOD or TSS loading. Growth of one provenance of Phragmites australis was limited by phosphate availability. However, populations of nitrifying bacteria were highest in samples of media and roots taken from plots containing this provenance. No correlation was demonstrated between nitrifying bacteria population and root biomass. Water stress caused by high media hydraulic conductivity and inadequate influent distribution resulted in sub-optimal conditions for reed growth in bed 1. The study concludes with details of the proposed design of a full scale system designed to treat up to 1000 m3 d-1 of beet processing effluents.

A pilot scale study of the dynamics of the break-up of curved liquid jets is presented. This work is motivated by an industrial process called prilling which is used in the manufacture of pellets. In this process a sieve-like cylindrical can spins rapidly on its central vertical axis. Molten liquid is pumped into the top of the can and flows from the holes in the form of curved liquid jets. Experiments are described which were carried out on a pilot scale rig. Some differences between the break-up modes observed in this study and previous work using a small laboratory scale rig are discussed. Previous theories describing break-up mechanisms of curved liquid jets were extended to include viscosity and gravity. Break-up lengths and drop sizes were obtained theoretically and compared with experimental results. Experiments were carried out using insonification, a process where sound waves are fired at the jet to control satellite drop formation. Three different frequencies of wave were used, 10, 100 and 200 Hz at four different rotation rates. It was observed that insonification was successful at eliminating satellite drops at low rotation rates and when frequencies of 100 or 200 Hz were used. Insonification was included in the theory. The theory predicted that insonification eliminated satellite drops for a large range of frequencies in the experimental regimes for sufficiently large acoustic volume. The theory also predicted that satellite drops were eliminated in parameter regimes outside the experimental regimes. The trajectory of the jet was allowed to become unsteady, in a rotating frame of reference. Simulations were carried out in inviscid and viscous regimes.

Phosphorus is one of the most important nutrients, which significantly influences the extraordinary growth of algae. Consequently, this leads to eutrophication of aquatic life. Eutrophication of water bodies due to phosphorus coming from wastewater is a serious problem. Therefore, additional work on many wastewater treatment plants is required in order to meet the required standards, particularly in relation to nutrient removal. Recently, continuous upflow filters CoUFs have been found to be a suitable technology for upgrading or expanding the wastewater treatment plants. On the other hand, investigation of different sorts of low-cost materials has been shown to be an attractive solution as phosphate sorbent materials PSMs, which represents a sustainable solution based on economical and environmental factors. This PhD study seeks to determine materials that are capable of removing phosphate from wastewater at tertiary treatment within a short time when they are packed in CoUFs. In order to select the suitable PSMs a comprehensive study has been conducted to describe their physical and chemical characteristics, affinity to retain orthophosphate (phosphate) and bonding time. This work was carried out through subjecting these materials to examinations such as scanning electron microscopy SEM and X-ray fluorescence analysis XRF to identify their characteristics, and conducting a batch test and constructing a lab-scale upflow filter to investigate the filter materials’ affinity to phosphate. Based on the phosphate removal efficiency and characteristics of selected materials an innovative and sustainable coating technology has been proposed to introduce a new type of filter material capable of removing phosphate effectively. Filtration materials coated with metallic oxides are presented as a good method for phosphate sorption. However, most of the researchers utilize chemicals as a source of metallic oxides and heating process to set the chemicals over the filtration materials. In this study, the method of creating new filter media involves coating a solid material via waste materials containing metallic oxides; the ordinary Portland cement (OPC) was utilized as a binder for the mixture materials. Water is the factor which is responsible for activating the OPC. All factors have been subjected to an optimization process. The results revealed that the limestone particles coated by furnace bottom ash (FBA) indicated a high capacity for phosphate sorption and possibility of regenerating their efficiency. In conclusion, this study introduces a new approach regarding creating and developing the characteristics of the filter media which fit the sustainability requirements.

Merchant marine officers have multiple specific duties and responsibilities to perform. Moreover, there is a need for a well-trained workforce to operate modern ships. In this era, the development of technological tools to assist in the delivery of the syllabus, and develop the marine cadets’ practical knowledge during training on-board is highly required. This study reviewed literature concerning Maritime Education and Training, in addition to personalised learning and online mobile learning. The research proposes the creation, assessment and validation of generic Interactive Maritime Education and Training (iMET) application, that is utilising Near Field Communication (NFC) technology, as a personalised interactive self-study mobile tool, with respect to cadets’ different learning preferences. The main aim of this research is to test the hypothesis that, the iMET tool has a direct positive impact on the Maritime Education and Training process on-board the training ship, and it is an accepted technology, hence will be actually used by the cadets on-board. In order to evaluate the research hypothesis, the researcher developed a generic prototype of iMET handheld application, as a proof of concept. Moreover, the researcher adapted a Technology Acceptance Model (TAM), from the existing TAM models, that had been used in previous research, in order to asses cadets’ acceptance to the proposed iMET application. Data collection in this research was based on triangulation, in order to measure the perception and expectations of the different maritime stakeholders affiliated with the iMET tool implementation. Accordingly, a questionnaire survey, a semi-structured interview and a quiz for cadets’ assessment was conducted. Data collection and surveys were conducted twice, in the pre iMET intervention development phase and post iMET intervention validation phase, in order to support justifying and validating the proposed technological tool in the current study. This research philosophy is a pragmatic research approach that applied a mixed methodology, to measure the cadets’ technology acceptance of iMET and their behavioural intention towards its actual usage. Finally, the research will discuss in detail the outcomes and finding.

This thesis reports on research work aimed at improving methods for predicting the fluid loading on fixed- and compliant offshore structures in waves. In focusing on slender member fluid-interaction models, the limitations and uncertainties associated with the widely-used Morison equation are examined. An improved empirical model has been developed and tested extensively alongside the Morison equation, using real experimental data. This improved model gives a better representation of the frequency dependency of the fluid-loading coefficients: this is particularly important in compliant motion conditions where the so-called relative velocity concept still needs to be verified under carefully controlled experimental conditions. The model is based entirely on the use of linear wave kinematics, thus simplifying calibration in irregular conditions and avoiding the need for a consistent non-linear wave theory (which is still lacking). By appropriate adaptation the improved model can also be extended to include amplitude dependency in the loading coefficients. The Improved Model has been developed through an analysis of experimental data. For this purpose the experimental work was focused on a horizontal cylinder, at model scale, located in a wave tank at the University of Sussex. The fluid loading experienced by a fixed cylinder, in both regular and irregular waves conditions, was measured and examined in detail. In addition, a comprehensive study of the loading on compliant cylinders, in both regular and irregular waves, was undertaken. Extensive use was made of appropriate parameter estimation techniques with initial attention (using simulated data) given to their accuracy for use with noisy experimental measurements. The effects of subtle (but undesirable) tank characteristics were also carefully taken into account. The study shows that, for fixed horizontal cylinders, benefits can be clearly identified in using the improved model, with frequency dependent coefficients, over the frequency dependent Morison equation. Moreover, the study shows that the relative velocity concept is more appropriate for use with the improved model than with the Morison model.

This thesis presents a novel approach to planning under uncertainty in resource constrained environments. Such environments feature in many real-world applications, including planetary rover and autonomous underwater vehicle (AUV) missions. Our focus is on long-duration AUV missions, in which a vehicle spends months at sea, with little or no opportunity for intervention. As the risk to the vehicle and cost of deployment are significant, it is important to fully utilise each mission, maximising data return without compromising vehicle safety. Planning within this domain is challenging because significant resource usage uncertainty prevents computation of an optimal strategy in advance. We describe our novel method for online plan modification and execution monitoring, which augments an existing plan with pre-computed plan fragments in response to observed resource availability. Our modification algorithm uses causal structure to interleave actions, creating solutions without introducing significant computational cost. Our system monitors resource availability, reasoning about the probability of successfully completing the goals. We show that when the probability of completing the mission decreases, by removing low-priority goals our system reduces the risk to the vehicle, increasing mission success rate. Conversely, when resource availability allows, by including additional goals our system increases reward without adversely affecting success rate.

In water conveyance systems, sudden changes in the flow velocity cause a phenomenon called waterhammer associated with high pressure head changes. Unless a control device is used as a precaution, waterhammer may result in costly damages and even in some cases, loss of human lives. In light of this concept, different control devices that can protect the systems against waterhammer are introduced so that the great pressure differences are absorbed and the system is maintained undamaged. In this thesis, the main functions, the requirements for its construction and the different types of the surge tanks are explained. The governing differential equations defining the flow conditions of the surge tanks and their solutions are provided. In addition, for the use of design engineers a procedure to determine proper dimensions of a surge tank is developed. For the sake of dimensioning the surge tank effectively, empirical equations, which calculate the height of three different types of surge tanks with dimensionless parameters, are obtained. With the help of regression analysis, the correlation between the parameters of the developed equations are determined, and found to be relatively high. Finally, the economical aspect of a surge tank is discussed and comparison parameters are introduced to the designer.

No description available.

Feasibility studies concerning decision-making for various types of items to be used in a small hydropower scheme is important for estimating the energy generation, the approximate cost of the project, and the required budget allocation. A computer program named RETScreen, which is commonly used in the North Americas, is capable of evaluating the energy generation, investment and maintenance costs for small hydro-projects. This thesis is based on application of this program to the Turkish practice. To this end, energy and cost equations dealing with energy generation and cost estimation of various items, such as costs of turbines, generators, installation of energy equipment, transmission line, etc., will be applied according to the common practice currently used in Turkey. A case study is performed to illustrate the use of this program. With the use of this program, it may be possible to perform quick successive runs to assess economic feasibility of several alternatives.