Engineering Commons^™

Modelling And Simulation Of Nonstationary Non-Gaussian Wind Speed And Wind Pressure Coefficients, Minyu Xiao

Electronic Thesis and Dissertation Repository

The time series of the wind speed from hurricane and downburst events can exhibit nonstationary non-Gaussian characteristics. Moreover, the time series of the wind pressure for a stationary wind may not be Gaussian. This thesis is focused on analyzing, characterizing, and simulating nonstationary/stationary Gaussian/non-Gaussian of wind speed and wind pressure coefficients by using time-frequency transform techniques such as the S-transform (ST) and discrete orthonormal S-transform (DOST). It is shown that by removing the mean of downburst winds, the multivariate nonstationary downburst wind speed processes can be efficiently decomposed and simulated by applying ST and DOST. It was also found that …

Assessment Of Tropical Cyclone Wind And Wave Hazards And Their Effect On The Reliability Of Wind Turbines, Chao Sheng

Electronic Thesis and Dissertation Repository

Tropical cyclone (TC) induces strong winds, heavy rainfalls, and storm surge. They cause fatalities and property damages, especially in the coastal regions that are prone to TC hazards. The TC wind or wave assessments were reported in the literature. The assessment provides the required hazard characterizations for assessing the reliability and risk of structures such as onshore and offshore wind turbines (WTs). The present study considered sites near the coastline of mainland China. It is focused on 1) the assessment of using different historical best-track datasets on the development of stochastic TC track models and on the estimated TC wind …

Uncertainties In Internal Pressure Of Oil Pipelines And Implications For The Reliability Analysis, Yue Liu

Electronic Thesis and Dissertation Repository

The internal pressure is the most important operational load for oil and gas pipelines. The maximum operating pressure (MOP) is the maximum pressure the pipeline is qualified to be operated according to a given standard. In deterministic fitness-for-service (FFS) assessment of in-service pipelines containing flaws such as corrosion defects and cracks, the remaining pressure containment capacity of the pipeline is evaluated and compared with MOP multiplied by a factor of safety to determine if immediate rehabilitation actions for the pipeline are necessary. However, the actual internal pressure of an in-service pipeline is however uncertain and fluctuates with time. Due to …

Finite Element Analysis Of Assembly For Warped Composite Automotive Components, Theogenes De Oliveira Maia

Electronic Thesis and Dissertation Repository

One of the most used processes in the automotive industry is the moulding of parts made of thermoplastics filled with glass fibres. This research focused on a specific material: long fibre thermoplastics (LFT). On the one hand, the performance gain, in terms of lightweight and the strength of final components, justifies its wide use. On the other hand, due to the intrinsic characteristics of part manufacturing, warpage is evident and can influence or even compromise subsequent stages of production.

This research has three main objectives: recreate in the most faithfully way, in Abaqus^TM environment, the conditions that precede the …

Intensification Of Clostridium Pasteurianum Fermentation Producing N-Butanol From Glycerol Using Microfiltration Cell Recycle, Colin W. Couper

Electronic Thesis and Dissertation Repository

This work demonstrates lab scale intensification of the fermentation of glycerol to 1-butanol using Clostridum pasteurianum, starting with simulation and comparison of different cell recycle arrangements, development of a cell recycle apparatus with an existing bioreactor, and demonstration of fermentation with the final system. Fermentations performed with the completed system showed that the cell recycle system was not significantly inhibitory to fermentation, and achieved a maximum apparent cell dry weight of 3.14g/L and a maximum butanol productivity of 1.16g/Lh.

Using A Systems Approach To Analyze The Operational Safety Of Dams, Leanna M. King

Electronic Thesis and Dissertation Repository

Dam systems are arrangements of interacting components that store and convey water for beneficial purposes. Dam failures are associated with extreme consequences to human life, the environment and the economy. Existing techniques for dam safety analysis tend to focus on verifying system performance at the edge of the design envelope. In analyzing the events which occur within the design envelope, linear chain-of-events models are often used to analyze the potential outcomes for the system. These chain-of-events models require that combinations of conditions are identified at the outset of the analysis, which can be very cumbersome given the number of physically …

Development And Validation Of A Probe Tube Placement Training Simulator, Robert Koch

Electronic Thesis and Dissertation Repository

For over 90% of individuals with hearing loss, hearing aids are the primary method of treatment. Recent studies have shown that most hearing aids are not personalized properly to patients, resulting in poor hearing outcomes. Poor training methods has been proposed as a possible reason for these findings.

A training simulator was developed consisting of a mannequin head with flexible, anatomically correct ears, and an optical tracking system for tracking the insertion of diagnostic equipment into a 3D printed ear canal. The simulator provides an outlet for trainees to practice their clinical procedures while receiving validated feedback, without the need …

Tropical Cyclone Wind Hazard Assessment For Southeast Part Of Coastal Region Of China, Sihan Li

Electronic Thesis and Dissertation Repository

Tropical cyclone (TC) or typhoon wind hazard and risk are significant for China. The return period value of the maximum typhoon wind speed is used to characterize the typhoon wind hazard and assign wind load in building design code. Since the historical surface observations of typhoon wind speed are often scarce and of short period, the typhoon wind hazard assessment is often carried out using the wind field model and TC track model. For a few major cities in the coastal region of mainland China, simple or approximated wind field models and a circular subregion method (CSM) have been used …

Optimal Sizing And Power Management Strategies Of Islanded Microgrids For Remote Electrification Systems, Faruk A. Bhuiyan

Electronic Thesis and Dissertation Repository

Over the past few years, electrification of remote communities with an efficient utilization of on-site energy resources has entered a new phase of evolution. However, the planning tools and studies for the remote microgrids are considered inadequate. Moreover, the existing techniques have not taken into account the impact of reactive power on component sizes. Thus, this thesis concentrates on optimal sizing design of an islanded microgrid (IMG), which is composed of renewable energy resources (RERs), battery energy storage system (BESS), and diesel generation system (DGS), for the purpose of electrifying off-grid communities. Owing to the utilization of both BESS and …

Delay Extraction Based Equivalent Elmore Model For Rlc On-Chip Interconnects, Shamsul Arefin Siddiqui

Electronic Thesis and Dissertation Repository

As feature sizes for VLSI technology is shrinking, associated with higher operating frequency, signal integrity analysis of on-chip interconnects has become a real challenge for circuit designers. For this purpose, computer-aided-design (CAD) tools are necessary to simulate signal propagation of on-chip interconnects which has been an active area for research. Although SPICE models exist which can accurately predict signal degradation of interconnects, they are computationally expensive. As a result, more effective and analytic models for interconnects are required to capture the response at the output of high speed VLSI circuits. This thesis contributes to the development of efficient and closed …

Optical-Wimax Hybrid Networks, Abdou R. A. Ahmed

Electronic Thesis and Dissertation Repository

The emergence of bandwidth-intensive Internet services, such as
circuit-quality voice transfer and interactive video gaming, create
a high demand for a very qualified next-generation access network.
In addition to high bandwidth, these future access networks should
also provide improved network availability, flexibility, mobility,
reliability, failure protection, quality of service (QoS) support
and cost-effective access. The integration between optical networks
and Worldwide Interoperability for Microwave Access (WiMAX) is a
promising solution for future access networks. Accordingly, a few
different architectures and MAC protocol components have recently
been proposed for the integration between the Ethernet Passive
Optical Network (EPON) and WiMAX. However, …