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Utilizing the introduction of slot controls at John F.

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Disc degeneration is noted by alterations in tissue structure and composition. Therefore, accurately measuring disc water content is important to develop accurate patient-specific disc model and to detect disc early degeneration. Our model predicted a decrease in equilibrium NP pressure from 0. The results highlight the need for policymakers to carefully consider how the allocation of airport slots will impact flight scheduling decisions when implementing similar policies in the future. However, MRI signal intensity is also dependent on scan-parameters, the concentration of free water molecules, and collagen fiber content and architecture. These findings are consistent with Ater , who suggested that policies aimed at reducing congestion at highly concentrated airports will only have a limited impact because dominant airlines already internalize congestion. To answer these questions, I developed finite element models for the intact disc joint and tissue subcomponents, including NP with AF and ex situ tissue explants NP and CEP tissue cubes, AF rings, and rectangular AF samples based on uniaxial test specimens. The location of NP centroid within the disc space had a significant impact on the magnitude and distribution of intradiscal pressure in flexion and extension. Utilizing the introduction of slot controls at John F. Disc malfunctions including herniation and degeneration are the main contributors to low back pain. Disc herniation occurs as NP extrudes through a damaged region of the AF, compressing the spinal nerves and causing neurologic dysfunction. It is argued that directional fare differences result from airlines recognizing that passenger price elasticities differ between route endpoints. Under single loading conditions, disc joint stiffness decreased with nucleotomy. Using quantitative magnetic resonance imaging MRI to measure disc water content is a promising approach, as signal intensity depends on the single proton density within the tissue and the approach is non-invasive. Experimental results showed that normalizing NP spin density by mass density provided an excellent agreement between MR measured water content and water content measured through lyophilization.

The results highlight the need for policymakers to carefully consider how the allocation of airport slots will impact flight scheduling decisions when implementing similar policies in the future.

The last chapter evaluates the effectiveness of slot controls restrictions on the number of departing and arriving flights as a congestion management policy. Simulation results showed: 1 Discs with collagen fibers oriented closer to the horizontal plane experienced a decrease in AF stresses, NP pressure, and torsional stiffness.

This discrepancy is likely due to a higher concentration of bound water molecules in the AF, compared to the NP, where tightly bounded water molecules have too short T2 values to be detected in MR imaging. However, normalizing spin density by mass density underestimated AF water content.

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Variations in GAG content and distribution replicated the healthy and degenerated discs. These changes alter stress distributions between NP and AF, resulting in altered disc joint mechanics during loading and unloaded recovery. The last chapter evaluates the effectiveness of slot controls restrictions on the number of departing and arriving flights as a congestion management policy. Disc herniation occurs as NP extrudes through a damaged region of the AF, compressing the spinal nerves and causing neurologic dysfunction. A finite element model of the human lumbar disc based on averaged disc geometry was developed and validated. Fluid flows out of the disc during the day and flows back at night exhibiting viscous effects. The location of NP centroid within the disc space had a significant impact on the magnitude and distribution of intradiscal pressure in flexion and extension. The results highlight the need for policymakers to carefully consider how the allocation of airport slots will impact flight scheduling decisions when implementing similar policies in the future. Using published fare and itinerary data from Google Flights, this chapter provides insight into both decisions by providing empirical estimates on the value of layover time in the U. Disc degeneration is noted by alterations in tissue structure and composition.

An airline is able to reduce a passenger's layover time by narrowing the gap between flights at the connecting airport. Such fare differences cannot be the result of differences in cost, as the cost of flying a roundtrip passenger does not significantly differ depending on direction.

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From the passenger perspective, layovers are detrimental since the addition to total travel time relative to a nonstop itinerary is a cost incurred by the passenger. This discrepancy is likely due to a higher concentration of bound water molecules in the AF, compared to the NP, where tightly bounded water molecules have too short T2 values to be detected in MR imaging. Water content is also a key parameter in disc computational models to simulate swelling behavior as well as nutrition transportation. To answer these questions, I developed finite element models for the intact disc joint and tissue subcomponents, including NP with AF and ex situ tissue explants NP and CEP tissue cubes, AF rings, and rectangular AF samples based on uniaxial test specimens. Collagen fibers in AF orient in a cross-ply pattern and fiber angle to the horizontal plane decreases from 43 degree in the inner AF to 28 degree in the outer AF. However, narrowing this flight gap has the adverse effect of increasing airport congestion. Although the disc structural mechanics has been extensively studied, there are still a lot of unknowns from the literature. An airline is able to reduce a passenger's layover time by narrowing the gap between flights at the connecting airport.

The discrepancy between single- and dual-loading conditions highlights the importance of evaluating disc joint mechanics under conditions that more closely represent in situ loading, which will be important for elucidating mechanisms for disc joint failure.

Then the validated model was modified to do parameter studies.

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Disc herniation occurs as NP extrudes through a damaged region of the AF, compressing the spinal nerves and causing neurologic dysfunction.

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