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Full-Text Articles in Mechanical Engineering

Measurement Of Stresses And Their Effect On Transport In Thin Film Battery Electrodes, Subhajit Rakshit Aug 2019

Measurement Of Stresses And Their Effect On Transport In Thin Film Battery Electrodes, Subhajit Rakshit

Dissertations

At the moment, there is a significant push towards environmentally friendly energy production and gasoline-free transportation technologies. As a result, there is a renewed interest in energy storage devices such as lithium-ion batteries which will play a key role in providing energy storage capability for these applications. However, the current battery technology is reaching its limits and may not meet future energy storage demands. The increased demand and the limited lithium reserves in geographically remote areas of the earth will lead to higher cost of Li. The alternative battery technologies, such as sodium-ion batteries, are promising due to their low …


Epitaxial Growth Of Iii-Nitride Nanostructures And Their Optoelectronic Applications, Moab Rajan Philip May 2019

Epitaxial Growth Of Iii-Nitride Nanostructures And Their Optoelectronic Applications, Moab Rajan Philip

Dissertations

Light-emitting diodes (LEDs) using III-nitride nanowire heterostructures have been intensively studied as promising candidates for future phosphor-free solid-state lighting and full-color displays. Compared to conventional GaN-based planar LEDs, III-nitride nanowire LEDs exhibit numerous advantages including greatly reduced dislocation densities, polarization fields, and quantum-confined Stark effect due to the effective lateral stress relaxation, promising high efficiency full-color LEDs. Beside these advantages, however, several factors have been identified as the limiting factors for further enhancing the nanowire LED quantum efficiency and light output power. Some of the most probable causes have been identified as due to the lack of carrier confinement in …


Mechanics Of Binder-Particle Interactions In Composite Battery Electrodes, Richard Johnson May 2019

Mechanics Of Binder-Particle Interactions In Composite Battery Electrodes, Richard Johnson

Theses

A study into the particle level mechanics of polymer binder and active material used in composite lithium-ion batteries (LIB) has been conducted. Silicon is highly sought after material that can be used as an active material in a composite anode. Its high theoretical capacity can result in batteries that can store more energy than current LIBs, but high volume expansion of Si during charge/discharge cycles leads to rapid capacity fade and poor cyclic life. Understanding the stress that is generated in the binder and the active material due to the volume expansion has not been fully understood. In this study …


Tomato Puree Convective Heat Transfer Simulation Using Boussinesq Approximation, Matteo Fabbri May 2019

Tomato Puree Convective Heat Transfer Simulation Using Boussinesq Approximation, Matteo Fabbri

Theses

With the advance of new technologies, the food industries are requiring systems that allow to produce the desired products with faster rates at cheaper costs. In this case, the study was initiated with the purpose to better understand what happens inside a package containing tomato puree when this is heated above 343 K in a tunnel pasteurizer. If the fluid must reach the thermal and microbiological condition of “pasteurization”, the system must guarantee that the temperature (around 343° Kelvin) is kept for a certain time allowing to pasteurize even the cooler package’s fluid-particle. The faster the system can heat the …


Effect Of Turbostratic Orientations And Confined Fluid On Mechanical Strength Of Bi-Layer Graphene: A Molecular Dynamics Study, Nil B. Dhankecha Jan 2019

Effect Of Turbostratic Orientations And Confined Fluid On Mechanical Strength Of Bi-Layer Graphene: A Molecular Dynamics Study, Nil B. Dhankecha

Theses

The rise of graphene as a reinforcement material in the last decade has been exponential owing to its superior mechanical properties. This one atom thick 2D material is applicable in many industries related to nanomechanical, nanoelectronics and optical devices. Despite its strength and superior properties, single-layer graphene tends to be unstable in a free-standing form. This led to active use of bi-layer and multilayered graphene in many of the above-stated applications. Though properties of single-layer graphene have been extensively investigated both computationally as well as experimentally for over a decade, bilayer graphene and its turbostratic form are still under research. …


Mechanical Design Automation: A Case Study On Plastic Extrusion Die Tooling, Allen Prasad Varghese Jan 2019

Mechanical Design Automation: A Case Study On Plastic Extrusion Die Tooling, Allen Prasad Varghese

Theses

The Skills Gap in Mechanical Engineering (ME) Design has been widening with the increasing number of baby boomers retiring (Silver Tsunami) and the lack of a new generation to acquire, practice and perfect their knowledge base. This growing problem has been addressed with several initiatives focused on attracting and retaining young talent; however, these types of initiatives may not be timely for this new group to be trained by an established Subject Matter Expert (SME) group. Automated Engineering Design provides a potential pathway to address not only the Skills Gap but also the transfer of information from SMEs to a …