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Analysis And Simulation Of The Pneumatic Braking System Of Freight Trains, Khaled Sayed Abdol-Hamid

Doctoral Dissertations

In North America, and in many other parts of the world, freight trains still employ pneumatic equipment for braking. The 26C locomotive valve and control valves of the cars are connected by a brake pipe which serves the dual purpose of conducting pneumatic power and transmitting the control signal (brake signal) from the locomotive to each car of the train. The development of the air brake system has been largely empirical and experimental, which may take years to develop a new design.

In this thesis, a new brake pipe mathematical model is developed, including the interaction of the branch pipe. …

Fire Resistance Of Concrete-Filled And Reinforced Concrete Columns, Mohamed El-Shayeb

Doctoral Dissertations

In order to calculate the fire resistance of a building component, it is necessary to know the temperature history of the component during exposure to fire. In this dissertation a numerical method is described for calculating the temperature field in fire-exposed columns. The procedure is based on a finite difference method for calculating the temperature history of concrete-filled square steel and cylindrical reinforced concrete columns. Two mathematical models and their related computer programs for these columns are presented in this dissertation.

Furthermore, the Division of Building Research of the National Research Council of Canada, is now carrying out extensive experimental …

An Investigation Of Aquatic Macrophyte-Based Aquatic Wastewater Treatment Systems For Temperate Climates (Elodea Nuttallii, Photosynthesis, Nutrient Budget, Active Transport, Nitrification), Thomas Taylor Eighmy

Doctoral Dissertations

Aquatic treatment systems are a low cost, low energy alternative to conventional treatment systems; they can provide secondary and advanced secondary wastewater treatment capabilities for small communities. Their potential application in temperate climates has been ignored. The research presented here was conducted to examine their applicability for use in temperate regions. A pilot-scale aquatic macrophyte-based aquatic treatment system was designed to treat primary effluent. Four aquatic macrophytes (Elodea nuttallii, Lemna minor, Myriophyllum heterophyllum, Ceratophyllum demersum) were evaluated as candidates. The hydraulic, organic, and nutrient loadings to the reactors were similar to design values for water hyacinth (Eichornia crassipes) systems. Nitrification …