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Full-Text Articles in Engineering

Tin-Silver As A Novel Biodegradable Metallic Biomaterial, Charley Goodwin May 2024

Tin-Silver As A Novel Biodegradable Metallic Biomaterial, Charley Goodwin

All Dissertations

The Essure device is a non-hormonal, minimally-invasive, permanent female sterilization implant, removed from the market due to an increase in adverse events, hypothesized to be caused by corrosion of the Sn-Ag component of the implant. The goals of this dissertation were to first develop implant retrieval methods for Essure devices and surrounding tissue, documenting signs of degradation and metallic degradation products, then to characterize the electrochemical behavior of Sn-Ag in biologically representative environments and finally, to assess the biological interaction of Sn-Ag. Retrieval analyses developed successful methods, qualifying the degree of corrosion, primarily of the Sn-Ag component and finding Sn …


Ti-6al-4v Β Phase Selective Dissolution: In Vitro Mechanism And Prediction, Michael A Kurtz Dec 2023

Ti-6al-4v Β Phase Selective Dissolution: In Vitro Mechanism And Prediction, Michael A Kurtz

All Dissertations

Retrieval studies document Ti-6Al-4V β phase dissolution within total hip replacement systems. A gap persists in our mechanistic understanding and existing standards fail to reproduce this damage. This thesis aims to (1) elucidate the Ti-6Al-4V selective dissolution mechanism as functions of solution chemistry, electrode potential and temperature; (2) investigate the effects of adverse electrochemical conditions on additively manufactured (AM) titanium alloys and (3) apply machine learning to predict the Ti-6Al-4V dissolution state. We hypothesized that (1) cathodic activation and inflammatory species (H2O2) would degrade the Ti-6Al-4V oxide, promoting dissolution; (2) AM Ti-6Al-4V selective dissolution would occur …


Mechanically- And Electrochemically- Induced Damage At Metal Interfaces Of Joint Replacements And The Biological Consequences, Pooja Panigrahi May 2015

Mechanically- And Electrochemically- Induced Damage At Metal Interfaces Of Joint Replacements And The Biological Consequences, Pooja Panigrahi

All Dissertations

Retrieval analysis has emerged as one of the most direct and informative ways to analyze mechanisms of orthopaedic device failure. With a rising projected demand for revision joint arthroplasty, 268,200 revision total knee replacements (TKR) and 96,700 revision total hip replacements (THR) in 2030, metal interfaces in joint replacements are currently under intense scientific focus as the interactions among mechanical and electrochemical processes continue to challenge the orthopaedic device industry. The objective of these studies was to use implant retrieval and in in vitro analyses to determine the effects of material and mechanical properties on wear and corrosion, and to …


Corrosion Activity In Precast Concrete Elements And Cementitious Closure Pours, Shabi Abbas Udaipurwala Aug 2013

Corrosion Activity In Precast Concrete Elements And Cementitious Closure Pours, Shabi Abbas Udaipurwala

All Theses

The use of prefabricated elements in the construction of highway bridges has been a common practice in the United States since 1950s. Precast concrete adjacent box beam girder bridges are quite popular given that the precast elements not only have structural capacity to span across the supports, but also form the bridge deck. These bridges have generally performed well during the initial years after construction, but recent failures in Pennsylvania and Indiana have aroused a nationwide alarm to investigate the causes of failure and find solutions to repair these bridges or develop design for new replacement bridges. It was found …


Study On Corrosion Activity Of Carbon Steel In Concrete Simulated Pore Solution Under Static Tensile And Compressive Stresses, Yujie Zhang Dec 2012

Study On Corrosion Activity Of Carbon Steel In Concrete Simulated Pore Solution Under Static Tensile And Compressive Stresses, Yujie Zhang

All Theses

Reinforced concrete is a structure material made up of concrete with relatively lower tensile strength containing reinforcements with higher tensile strength and better ductility, which are embedded into fresh concrete to resist tensile stress in certain regions of concrete. Steel reinforced concrete is most widely used around the world in civil engineering structures, water conservancy and highway construction due to its durability strength and reasonable cost.
However, reinforced concrete structures such as bridges and parking lots slabs inevitably experience variable loads and constant degradation from the aggressive environments, such as marine and deicing salts. Therefore, it is imperative to study …


Durability Of Reinforced Concrete Incorporating Crushed Waste Brick As Coarse Aggregate, Matthew Adamson Dec 2012

Durability Of Reinforced Concrete Incorporating Crushed Waste Brick As Coarse Aggregate, Matthew Adamson

All Theses

Using crushed bricks as aggregates in concrete is of particular interest to preserve natural aggregate sources as well as to reduce waste, as it has been estimated that 10% to 30% of all waste in landfills in the united States comes from construction and demolition wastes. By recycling some of these wastes, the sustainability of a project can be improved. However, it is important concrete incorporating these wastes is as durable or more durable then conventional concrete, or will it have a shorter service life. Durability of concrete is its ability to resist deterioration from its external environment such as …