Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"VOLUMETRIC EXPANSION"”.
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Three dimensional characterization of failure evolution of tin and silicon in lithium ion battery electrodes
… is accompanied by significant volume expansion, resulting in particle fracture and subsequent loss of functionality. In this work, the utilization of Sn and Si as high capacity alternate host materials in the form of particles within composite electrodes or wire was investigated in …
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Coupled mechanochemical theories for reacting systems with application to nanovoid nucleation and Li-ion batteries
… Li. However, insertion of Li leads to 334 % of volumetric expansion, huge stresses, and fracture; it can be suppressed by utilizing nanoscale anode structures. Continuum approaches to stress relaxation in Li<sub>x</sub>Si, based on plasticity theory, are unrealistic, because the yield strength …
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Predicting the Influence of Hydrogen on Zirconium
… of the alloy as well as additional strain due to volumetric expansion. With the aid of Finite Element Analysis, this thesis describes models of the diffusion of hydrogen in response to gradients in stress, temperature, and concentration; the nucleation of hydride; and the growth of hydride. The …
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A constitutive model for the compression behavior of Old Alluvium
… theory is integrated to predict macroscopic volumetric expansion due to the swelling of the nontronitic clay fraction. This behavior is also linked to the Cation Exchange Capacity through the preconsolidation stress level, and hence, can accommodate changes in the clay swelling potential …
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Modeling of multiphase turbulent flow in continuous casting of steel
… such as coalescence, breakup, shearing off and volumetric expansion is proposed. Also, a simple 1D pressure energy model is developed to estimate pressure distribution in multiphase flow systems with complex geometry. These newly developed models are applied to estimate the flow pattern …
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Sulfur-Based Yolk-Shell Nanoparticles for Lithium Sulfur Batteries
… of the intermediate polysulfide and the large volumetric expansion of the material in the cell upon lithiation (~80%). Sulfur yolk-shell nanostructures were designed to improve the electrical performance of the lithium sulfur batteries. In the initial study, a sulfur@silica@porous gold …
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Development of a constitutive model for a heaving clay from Rosebank
… mineral. When exposed to free water they undergo volumetric expansion, which often results in differential movements at the surface and damage to building structures founded on the clay. The economic consequences of such damage is severe. Heaving clay causes in excess of R100 million damage in …
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Structural engineering of lithium-ion battery electrodes for the production of stable, energy-dense storage
… Typically, the large mechanical stress from the volumetric expansion during lithiation causes severe capacity fade in these materials; however, implementing a carbonaceous scaffold can drastically increase the stability of these materials. In addition to examining new active materials, the …
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Microstructural study of intergranular M23C6 precipitates in Alloy 709
… aging time, the stress became higher due to the volumetric expansion of the M23C6 precipitates. The crystallographic characteristics of the intergranular M23C6 were investigated analyzing diffraction patterns of the intergranular M23C6 precipitates and the neighboring austenite. The intergranular …
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Electro-chemo-mechanics of solids: application to all-solid-state batteries, polyelectrolyte gels, and actuators.
… concentration gradients, which can cause local volumetric expansion and contraction. Since stresses and strains are transmitted very effectively in solids, the chemical expansion leads to significant stress generation in the host material. These stresses also influence the movement of ions, and …
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Function Follows Form: An Exploration of Robotic Embodiment through Geometry
… use a motorized auxetic shell to control their volumetric expansion. Since the AuxBot’s expansion was achieved purely through geometry, I had significant control over the design space. I created AuxBots optimized for speed and expansion ratio (390% volume expansion in 0.2 seconds) or for force …
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A Boundary Element Method for Thermo-poroelasticity with Applications in Rock Mechanics
… due to the fact that thermal loading induces a volumetric deformation because of thermal expansion/contraction of both the pore fluid and the rock solid. Volumetric expansion can result in significant pressurization of the pore fluid. In order to take into account the influence of temperature …
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Mechanics of lithium-ion battery electrodes
… of composite graphite electrodes. The large volumetric expansion of silicon during lithiation (ca. 300 - 400 %) caused the electrodes to fracture and pulverize where they were attached to a substrate, which frustrated in situ strain measurements. Therefore, strain was measured only during the …
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Polymer and Concrete Composites in Industrial and Infrastructure Applications
… of elasticity, and coefficient of thermal expansion were tested and compared against another rapid repair material. The Tri-Service Pavements Working Group Manual recommendations for rigid repair materials were used as the requirements in determining whether the polymer concrete was an …
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The development of a prototype external heat engine based on the Ericsson cycle
… the engine to convert heat to mechanical work by volumetric expansion. The project looked at old and new engines in an attempt to capture the best of both. Two experimental engines were constructed during the course of this project, the first engine was built to provide insight into the functioning …
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Directed lithium transport in high capacity lithium-ion battery electrodes
… intercalation to control the direction of volumetric expansion, the volume available for expansion and thus the charging capacity of these structures can be broadly varied. Chapter 3 examines the properties of microstructured Ge electrodes for Li-ion battery applications. Unlike Si …
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Study of Interfacial Chemical Reactions on Battery Electrodes Using Operando Imaging Techniques
… Non-uniform Li growth will cause significant volumetric expansion of the Li metal anode and break the formed SEI, leading to more electrolyte consumption and aggravating the dendrites formation. The concerted operando RIM enables the real-time imaging of the entire Li nucleation process with …
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Investigating casein-polymer interactions as a platform technology for cheese for Asian consumers
… such as colour and volatile compounds. The volumetric expansion during puffing process was significantly (p<0.05) decreased by addition of KG, and increased by addition of CH, respectively; this showed that polysaccharides may be used in modifying texture of cheese puffs. Overall, the work …
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Comprehensive Computational Modeling of Hypergolic Propellant Ignition
… leading to instabilities due to rapid volumetric expansion, which is characteristic of phase change. Resulting instabilities are anticipated to promote liquid mixing, reactions and additional instabilities. However, intermittent contact and limited liquid interaction is seen to be the …
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Molecular-level interphase design for sustainable batteries
… anode, which is capable of alleviating volumetric expansion while strengthening the electrical connectivity in the electrodes with an average CE over 99.9% in a high-loading full cell, is developed based upon a robust Si-O-C covalent bonding by molecular-level interphase wiring. …