Posterior pedicle screw and rod fixation has become standard in the treatment of oncological resections requiring stabilization, deformity correction and unstable thoracolumbar fractures. Given the high mechanical stress at the points of highest instability, some clinicians have utilized dual rods on each side to augment the construct. The added advantage of this type of construct has not been previously evaluated in-vitro. The goal of this study is to evaluate the biomechanical advantage of a dual rod construct in the thoracolumbar spine, using a burst fracture cadaveric model. Methods: Seven fresh human cadaveric (T9-L3) spines were tested in normal conditions, after an iatrogenic T12 burst fracture, and successively after laminectomy and standard two rod pedicle screw stabilization (two level above and two below) and two different dual rod overlapping constructs. Pure moment torque was applied quasistatically, while 3D motion was measured optoelectronically. Thoracolumbar range of motion was measured during flexion, extension, left / right lateral bending, and left / right axial rotation. Results: All constructs significantly stabilized the simulated burst fracture in all modes of testing. There was no statistically significant difference, however, in the ability to restrict motion between the 3 different constructs, either from T10-L2, or across the fracture segment of T11-L1. Conclusions: There does not appear to be a biomechanical advantage to using dual rods over standard single rods for immediate fixation in an unstable segment. Whether dual rods protect the construct against long-term failure is not yet known.

In a pressurized water reactor (PWR), pressurized water flows over fuel rods containing radioactive uranium. Potential failure of these nuclear fuel rods is a primary concern, as fuel rod failure typically results in power generation losses and reactor downtime. Thermal parameters such as critical heat flux have traditionally been utilized as performance metrics to ensure that the reactor core remains stable even during failure events. Recently, fuel leaking events have occurred which have resulted in excess debris buildup on fuel rods and fuel grid array mixing devices. Understanding the flow field surrounding these nuclear fuel rods is critical in predicting where crud could deposit. Although CFD simulations have been conducted to characterize the fluid flow around fuel rod bundles, limited experimental data characterizing the mechanics of this fluid flow exists in the current literature. This study will present experimental data collected detailing the fluid flow around a rod bundle geometry using a novel matched refractive index particle tracking velocimetry (PTV) technique over a 3D volume cross section of a prototypical nuclear fuel rod bundle. Velocimetry tracking will be performed in order to characterize the mechanics of the fluid flow. Using optical distortion mitigation techniques and various image processing methods, data from multiple cameras was used to assemble 3-dimensional velocity information of a turbulent fluid region. Results are compared to the solution of a k-epsilon unsteady RANS numerical simulation.

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Thesis (B.Sc.(Hons.)-- University of Adelaide, Dept. of Psychology, 1974.

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The thesis deals with the issue of cultural landscape and composed landscapes in general. There is marginally solved also an issue of dealing with composed landscapes nowadays. The model territory is the village cadastre of Křinec near the Nymburk. The landscape was the subject of a detailed analysis of primary and secondary landscape structure. Historical landscape structure and layer composed landscapes were thoroughly discussed and on the basis of the available materials there were defined stages of their development. The findings were illustrated in cartography and drawing diagrams. The analysis part was the starting point for defining the values and problems of the model area. These were crucial for the design part, which output is the landscape study. The landscape study addresses three basic design layer, a layer composed landscape, an ecological stability of the area and working relationships.

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One of two project reports. The other one is designated PART A: McMASTER (ON-CAMPUS) PROJECT / <p> A reactivity meter code based on point kinetics was developed. Rod-drop experiments performed in the ZED-2 reactor tested the code for various detector and rod-drop positions. A delayed neutron hold-up effect was observed whenever a rod was dropped close to a detector. A better understanding of this effect was obtained through a theoretical analysis of the pertinent experiments. The three-dimensional kinetics code, CERBERUS, was used for the theoretical analysis. </p> / Thesis / Master of Engineering (MEngr)

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