Mechanical Engineering Commons^™

Acoustic Design Optimization With Isogeometric Analysis And Differential Evolution, Garrett W. Dodgen

Mechanical Engineering Theses

The objective of this study is to utilize shape optimization to enhance the performance of devices relying on acoustic wave propagation. Particularly, the shape of a horn speaker and an acoustic energy harvester were optimized to enhance their performance at targeted frequencies. High order Isogeometric Analysis (IGA) was performed to estimate the acoustic pressure with minimum geometry and pollution errors [1]. The analysis platform was then combined with Differential Evolution (DE) to optimize the geometry of the horn speaker and energy harvester at a given frequency. These cases effectively demonstrate two applications of Isogeomtric shape optimization for devices relying on …

Integrated Design Approach For Coronary Stents Using Flexinol Shape Memory Alloy, Matthew Lucci

Mechanical Engineering Theses

This research seeks to develop and verify a model for control of the shape memory alloy (SMA) Flexinol and apply such findings to practical application of the material as a platform for bare metal stenting technologies. Utilizing experimental data and material properties, a mathematical model of the thermoelectric contraction behavior of Flexinol wire samples was developed. This model accounted for variable resistance due to the shape memory effect of the Flexinol wire as it experiences a crystalline phase change. It also accounted for the change in the cross-sectional area of the wire as the wire experienced thermal expansion and contraction. …

Thermoresponsive Switchable Solvents For Enhanced, Simultaneous Microalgae Oil Extraction Reaction For Biodiesel Production, Mukhtar Ahmed Ismail

Mechanical Engineering Theses

In this study, a thermo-responsive switchable solvent (TSS), with a tunable hydrophobicity by simply changing the temperature (between 25 to 45oC) was used for simultaneous lipids extraction from wet microalgae and biodiesel production. By manipulating the hydrophobicity of the solvent, the cell wall disruption, lipid extraction and transesterification, and product separation steps were all carried out in a single pot, while eliminating the need for the energy intensive and time-consuming drying step. To overcome the problems currently encountered by using conventional alkaline catalysts in the transesterification of lipids, immobilized enzyme has been used. The proposed TSS consisted of an ionic …

Physicochemical Properties Of Blend Poly (Vinyl Alcohol) And Sodium Alginate Membranes For Potential Application In Wound Dressings, Martha Pieper

Mechanical Engineering Theses

Poly (vinyl alcohol) (PVA) and sodium alginate (SA) are water-soluble polymers with excellent biocompatibility suitable for biomedical applications in wound dressings. In this study, pure PVA, pure SA, and blends of PVA/SA membranes were solvent cast into films followed by crosslinking in CaCl₂, boric acid, and a mixture of CaCl₂/boric acid solutions for 5, 10, and 30 minutes. Initial feasibility studies showed a strong correlation of film thickness to the observed mechanical properties. Further studies in solvent casting of blend PVA/SA films, using various polymer concentrations, yielded better film appearance with minimal physical changes after crosslinking. …

Acute Angle Repositioning In Mobile C-Arm Using Image Processing And Deep Learning, Armin Yazdanshenas

Mechanical Engineering Theses

During surgery, medical practitioners rely on the mobile C-Arm medical x-ray system (C-Arm) and its fluoroscopic functions to not only perform the surgery but also validate the outcome. Currently, technicians reposition the C-Arm arbitrarily through estimation and guesswork. In cases when the positioning and repositioning of the C-Arm are critical for surgical assessment, uncertainties in the angular position of the C-Arm components hinder surgical performance. This thesis proposes an integrated approach to automatically reposition C-Arms during critically acute movements in orthopedic surgery. Robot vision and control with deep learning are used to determine the necessary angles of rotation for desired …

Development Of A Hybrid Residential Hvac System: An Experimental Study Of A Variable Refrigerant Flow System With Ducted And Ductless Elements, Andrew C. Hernandez Iii

Mechanical Engineering Theses

The introduction of variable refrigerant flow (VRF) expands the range of development potential for HVAC systems. The hybridization of traditional HVAC ducted systems and ductless VRF integrates both the advantages and disadvantages of each system type. Existing research does not focus on hybridization but on individual component evaluation that covers quantitatively expansive evaporator or multiple compressor configurations. The Trane Residential Heating and Cooling Research Lab at the University of Texas at Tyler was used as the research facility to experiment and validate a hybrid ducted-ductless HVAC system where a ducted attic air handler unit and three ductless evaporator units were …

System Integration Of C-Arm Robotic Prototype Using Motion Capture Guidance For Accurate Repositioning, Alireza Yazdanshenas

Mechanical Engineering Theses

One of the important surgical tools in spinal surgery is the C-Arm X-ray System. The C-Arm is a large “C” shaped and manually maneuvered arm that provides surgeons and X-ray technicians the ability to take quick quality X-rays during surgery. Because of its five degrees of freedom, the C-Arm can be manually maneuvered around the patient to provide many angles and perspectives, ensuring surgical success.

This system works fine for most surgical procedures but falls short when the C-Arm must be moved out of the way for complicated surgical procedures.

The aim of this thesis is to develop an accurate …

Building A Simple Smart Factory, Iman Abdulwaheed

Mechanical Engineering Theses

This thesis describes (a) the search and findings of smart factories and their enabling technologies (b) the methodology to build or retrofit a smart factory and (c) the building and operation of a simple smart factory using the methodology. A factory is an industrial site with large buildings and collection of machines, which are operated by persons to manufacture goods and services. These factories are made smart by incorporating sensing, processing, and autonomous responding capabilities.

Developments in four main areas (a) sensor capabilities (b) communication capabilities (c) storing and processing huge amount of data and (d) better utilization of technology …

Experimental Investigations Of Bio-Syngas Production Using Microwave Pyrolysis Of Uae’S Palm Date Seeds, Mahmmoud Muhammed Syam

Mechanical Engineering Theses

From the start of the industrial revolution, the continued need for energy has been the most crucial issue in human history. An energy crisis started at the beginning of the 1970s when the number of machines, which became an essential part of our life, increased rapidly. Scientists made a huge effort to discover new sources of energy, with ‘biomass’ being one of the main focuses of researchers as a new renewable source of energy. In this thesis, a non conventional method of heating, using microwave power in a pyrolysis process of biomass waste from palm trees (Allig’s date seeds) for …