Engineering Commons^™

Design, Microstructure And Properties Of Metastable Beta-Type Biomedical Titanium Alloys, Syed Faraz Jawed

Theses: Doctorates and Masters

Many existing implant biomaterials including cobalt-chromium alloy, stainless steel, Ti-6Al-4V and commercially pure titanium have all been shown to demonstrate mechanical incompatibility, poor osseointegration and/or cause cytotoxic effects on the human body after some years of application, leading to revision surgery in most cases. Consequently, there is an immediate need for an enduring biomaterial that displays good mechanical properties and possesses biocompatibility and corrosion resistance, in order to reduce rates of revision surgeries. In this PhD work, based on the 𝐵𝑜̅̅̅̅-𝑀𝑑̅̅̅̅̅, 𝑒/𝑎̅̅̅̅̅-𝛥𝑟̅̅̅ and BF-d-electron superelastic theoretical relationships four new series of quaternary Ti-25Nb-8Zr-xCr, Ti-25Nb-xSn-yCr, Ti26Nb-xMn-yZr and Ti-25Nb-xMn-ySn alloys have been …

A Solar‐Driven Membrane‐Based Water Desalination/Purification System, Abdellah Shafieian Dastjerdi

Theses: Doctorates and Masters

Lack of fresh water has turned into one of the major challenges of the world in the present century. Desalination of brackish or seawater has been proven to be one of the best solutions to cope with this global challenge. Among all the desalination methods, Membrane Distillation (MD) is well known as a cost effective and profitable technology for treating saline water. However, higher energy consumption compared to other separation techniques has been reported as MD’s main drawback. That is why the application of solar energy to provide the thermal energy requirement of MD modules has been the focal point …

The Integration Of Pumped Hydro Storage Systems Into Pv Microgrids In Rural Areas, Navid Mousavi

Theses: Doctorates and Masters

Photovoltaic (PV) systems are popular in rural areas because they provide low cost and clean electricity for homes and irrigation systems. The primary challenge of PV systems is their intermittent nature. The typical solution is storing energy in batteries; however, they are expensive and possess a short lifespan. This research proposes a new type of pumped hydro storage (PHS) which can be implemented as an alternative to batteries. The components of the system are modelled to consider losses of the system accurately. The mathematic model developed in this project assists the management system to make more efficient decisions. The proposed …

Application Of Advanced Algorithms And Statistical Techniques For Weed-Plant Discrimination, Saman Akbar Zadeh

Theses: Doctorates and Masters

Precision agriculture requires automated systems for weed detection as weeds compete with the crop for water, nutrients, and light. The purpose of this study is to investigate the use of machine learning methods to classify weeds/crops in agriculture. Statistical methods, support vector machines, convolutional neural networks (CNNs) are introduced, investigated and optimized as classifiers to provide high accuracy at high vehicular speed for weed detection.

Initially, Support Vector Machine (SVM) algorithms are developed for weed-crop discrimination and their accuracies are compared with a conventional data-aggregation method based on the evaluation of discrete Normalised Difference Vegetation Indices (NDVIs) at two different …

Investigating Optimum Wavelength(S) For Growth Of Lactuca Sativa, L. Using Tunable Led Sources And Developing Thin-Film Filters For Glass Greenhouses, Jacqualine Anne Thomas

Theses: Doctorates and Masters

With the increase in world population, the continued advances in modern greenhouse agriculture and plant growth practices are expected to help overcome the global problem of future food shortages. This research investigates a way to assist in stemming the problem of food shortage by using optimised light irradiation (within the constraints of the experiment) on a sample plant species of lettuce (Lactuca sativa, L.). Whilst lettuce is often grown in hydroponic systems, the current research is conducted in stand-alone pots with hand watering, due to the requirements of health and safety and available resources.

The experiments were designed …

Proactive Content Caching In Future Generation Communication Networks: Energy And Security Considerations, Muhammad Ishtiaque Aziz Zahed

Theses: Doctorates and Masters

The proliferation of hand-held devices and Internet of Things (IoT) applications has heightened demand for popular content download. A high volume of content streaming/downloading services during peak hours can cause network congestion. Proactive content caching has emerged as a prospective solution to tackle this congestion problem. In proactive content caching, data storage units are used to store popular content in helper nodes at the network edge. This contributes to a reduction of peak traffic load and network congestion.

However, data storage units require additional energy, which offers a challenge to researchers that intend to reduce energy consumption up to 90% …

Microstructure And Mechanical Behavior Of Metastable Beta Type Titanium Alloys, Chirag Dhirajlal Rabadia

Theses: Doctorates and Masters

Current biomaterials such as stainless steel, Co-Cr alloys, commercially pure titanium and Ti-6Al- 4V either possess poor mechanical compatibility and/or produce toxic effects in the human body after several years of usage. Consequently, there is an enormous demand for long-lasting biomaterials which provide a better combination of mechanical, corrosion and biological properties. In addition to this, alloys used in high-strength applications possess either high-strength or large plasticity. However, a high-strength alloy should possess a better blend of both strength and plasticity when used in high-strength applications. Metastable β-titanium alloys are the best suited alloys for biomedical and high-strength applications because …

Application Of Heat Pumps And Thermal Storage Systems For Improved Control And Performance Of Microgrids, Ali Baniasadi

Theses: Doctorates and Masters

The high penetration of renewable energy sources (RES), in particular, the rooftop photovoltaic (PV) systems in power systems, causes rapid ramps in power generation to supply load during peak-load periods. Residential and commercial buildings have considerable potential for providing load exibility by exploiting energy-e_cient devices like ground source heat pump (GSHP). The proper integration of PV systems with the GSHP could reduce power demand from demand-side. This research provides a practical attempt to integrate PV systems and GSHPs e_ectively into buildings and the grid. The multi-directional approach in this work requires an optimal control strategy to reduce energy cost and …

A Study Into The Effects Of Spray And Jet Characteristics On Flash Evaporation System, Farshid Fathinia

Theses: Doctorates and Masters

Low temperature flash evaporation desalination is a separation system that isolates liquids from other materials when seawater or any fluid undergoes evaporation. Extreme flash evaporation occurs when a low heated liquid is injected into the vacuum area, where the pressure is far below the saturated pressure of the liquid entering the area. This approach of flash evaporation is a key part of this type of system. It has a great potential to develop and improve the implementation of low thermal desalination plants but requires more specific study. Further analysis shows that previous investigations have not given a comprehensive insight into …