Engineering Commons^™

Robust Colour Segmentation Under Dynamic Lighting Conditions, Noreen Mary Looney

Theses

Traditionally, the issue of colour constancy has limited the success of colour image segmentation algorithms. Numerous methods exist to achieve colour constancy for different applications. The principal contribution of this thesis is the investigation of a suitable technique for the problem of robust colour based object detection.

Appropriate colour models are investigated and analysed in order to assess their ability to enhance the isolation process. Models that possess suitable colour constancy characteristics are chosen for use with image segmentation algorithms. Reviews of existing sur\'eys of image segmentation algorithms are appraised for the emergence of a suitable colour image segmentation technique. …

Dredging And Dredge Disposal And Reuse In Ireland, Séamus Sutton

Theses

Dredging involves raising material from a river or estuary bed to the surface and transporting it some distance for disposal or reuse. It may be required to improve navigational access, to allow for port development or for mining aggregates.

This thesis includes a literature review and a detailed study of the dredging industry in Ireland. This study is partly based on a nationwide survey undertaken on dredging and dredge disposal and reuse, the results of which are included in a dredging database created for this project. All the main stakeholders in the industry were invited to complete questionnaire forms for …

Ductile Crack Growth Emanating From Sharp Notes In A Low Alloy Steel, Aladdin I. Abu-Assi

Theses

Stable crack growth behavior emanating from a sharp notch is investigated. Material chosen for tests was EN 34 NiCrMo6 low alloy steel (akin to 4340/4330). Tests were carried out on CT specimens for various angles and ratios to obtain load vs, load-line displacement, Ρ-Δ_LL, curves. Experimental results were analyzed. A normalization approach of Ρ-Δ_{LL curves has been attempted and all experimental curves were represented as a single characteristic curve. Such approach has been also applied on experimental data available from other experimental investigations and results were encouraging, as it may address transferability issue. Fracture surfaces were …}

Investigations Of The Kinetics Of Liquid Droplets On Soil Substrates Using A Novel Approach: Contact Ratio, Abdelhafiz “Moh’D Adnan” Herbawi

Theses

In view of young’s equation, in which the contact angle “ϑ” and the liquid surface tension γ_lv are the only measurable parameters, the contact angle has been widely conceived as a thermodynamic quantity. Accordingly “ϑ” has been the main focus of most theoretical and experimental investigations. The rate of change in the contact angle has been commonly used as the relevant parameter of spreading dynamics in spite of difficulties associated with contact angle measurements that are well recognized in the literature. Considering that the velocity of the contact line is the pertinent quantity for spreading, it is therefore reasonable …

Thermal And Mechanical Properties Of Polyethylene-Polypropylene Blends, Rania Omar Akkad

Theses

The thermal and mechanical characteristics of thermally treated and untreated pure polyethylene (PE), pure polypropylene (PP) and their blends were investigated. Injection-moulded samples containing 100:00,75:25,50:50,25:75 and 00:100 weight percentage of PE:PP, were prepared and thermally treated at 100°C for 0, 2, 4, 7, 14 days. The treated samples were subjected to differential scanning calorimetry (DSC), thermogravimetry (TG & DTG), infrared spectral analysis (IR) and tensile tests in order to study the effect of thermal treatment and blending ratios on their thermal and mechanical properties. The results indicate that addition of PE causes the melting temperature (T_m) of PP …

Effect Of Bond Thickness On Lifetime Of Adhesive Joints, Ehab Mohammed El-Said El-Refaai Shehab

Theses

The aim of this research was to study the effect of bond thickness on the fracture energy and the lifetime of an adhesively bonded system and develop a model to predict the lifetime of adhesive joints. An approach based on fracture mechanics was employed to assess aluminum/epoxy bond lifetime. An experimental investigation was carried out using double cantilever beam (DCB) specimens with various bond thicknesses under mode 1.

This study describes an approach to predict the rate of crack propagation using Paris' power law. The approach used elevated temperatures to accelerate the crack propagation under constant loads. The elevated temperatures …

Investigation Of Epoxy Resin Spreading On Glass Surfaces, Haneen Nemer Al-Dahdooh

Theses

The spreading of a small epoxy resin droplet (l.5tL) on a glass surface was examined with the objective of developing a new type of hydrophobic polymer coated glass which has the ability to reduce heat gain inside a building. The study covered three main aspects; the spreading kinetics of epoxy resin on a glass surface, the hydophopicity of the developed polymer-coated glass surface, and the reduction of solar radiation of this surface, As wettability and spreading phenomena arc a fundamental prerequisite for coating, the spreading kinetics of different curing agent concentrations (15:200, 18:200, 21:200) of epoxy resin on the glass …

Microwave Processing Of Fiber Reinforced Composites (Optimization Of Glass Reinforced Epoxy Curing Process), Mohamed Osama Ali

Theses

Microwave curing of polymer matrix composites has proven to be an attractive substitute for conventional thermal curing. Industrial applications are currently developed including telecommunications, aerospace, food industry, enhancement concrete setting, composites manufacturing, and many others. Many universities and research centers around the globe are endeavoring to make use of this technology to the most. Common research objectives include homogeneity of the cure, the acceleration of cure kinetics, cure reaction mechanism, and enhancement of mechanical properties. In order to efficiently utilize this form of energy, precise control over power, temperature, and time were applied to achieve set goals: reduce cure time …

Heat Transfer Model For The Ignition Of Metal Powder On A Heated Filament, Trent Stanton Ward

Theses

The thermal processes leading to ignition of metal powders in environments that experience rapid temperature changes are currently poorly understood. In this research, a methodology for studying and quantification of such processes is developed. In the experimental case study, the ignition temperature of Mg powder coated on the surface of an electrically heated filament is detected optically at different heating rates. To interpret the results, a heat transfer model has been developed for a multilayer powder coating on top of an electrically heated filament. The coating is modeled using a hexagonal close packed geometry and the heat transfer equations are …