Clt infill panels in steel moment resisting frames as a hybrid seismic force resisting system

This paper examines CLT-steel hybrid systems at three, six, and nine storey heights to increase seismic force resistance compared to a plain wood system. CLT panels are used as infill in a steel moment frame combining the ductility of a steel moment frame system with a stiffness and light weight of CLT panels. This system allows for the combination of high strength and ductility of steel with high stiffness and light weight of timber. This thesis examines the seismic response of this type of hybrid seismic force resisting system (SFRS) in regions with moderate to high seismic hazard indices. A detailed non-linear model of a 2D infilled frame system and compared to the behavior of a similar plain steel frame at each height. Parametric analysis was performed determining the effect of the panels and the connection configuration, steel frame design, and panel configuration in a multi-bay system. Static pushover loading was applied alongside semi-static cyclic loading to allow a basis of comparison to future experimental tests. Dynamic analysis using ten ground motions linearly scaled to the uniform hazard spectra for Vancouver, Canada with a return period of 2% in 50 years as, 10% in 50 years, and 50% in 50 years to examine the effect of infill panels on the interstorey drift of the three, six, and nine storey. The ultimate and yield strength and drift capacity are determined and used to determine the overstrength and ductility factors as described in the National Building Code of Canada 2010.Applied Science, Faculty ofCivil Engineering, Department ofGraduat

Virtual micro MLC commissioning

The resolution of multileaf collimators (MLCs) is limited by their finite leaf width. A commercial package (HD-270™) uses 3D couch translation and leaf adjustments to emulate smaller leaf widths. In this paper, we report on the commissioning of this feature using software testing, dial gauge measurements, and film dosimetry. We also identify a variety of limitations: software bugs and truncation artifacts, MLC leaf positioning uncertainties (random variations, systematic gantry dependence and backlash), and uncertainties in couch positioning. These reduce the capabilities of this implementation below that achievable theoretically. PACS numbers: 87.53.Kn, 87.53.Uv, 87.53.Xd Key words: multileaf collimator, leaf resolution, quality assurance, HD-27

Prophylactic Cranial Irradiation Revisited: Cost-effectiveness and Quality of Life in Small-cell Lung Cancer

PURPOSE: To investigate the therapeutic usefulness and cost-effectiveness of prophylactic cranial irradiation (PCI) in patients with limited-stage small-cell lung cancer (SCLC) who had achieved a complete remission. METHODS: A retrospective chart review was undertaken of all patients diagnosed in Saskatchewan with SCLC between 1987 and 1998 inclusive. Patients who achieved a complete remission were divided into two groups, depending on whether they underwent PCI (PCI+ and PCI-, respectively). The quality-of-life-adjusted survival was estimated by the Q-TWiST method (quality time without symptoms and toxicity). The mean incremental costs per month of incremental OS were calculated in a cost-effectiveness analysis. RESULTS: Among the 98 complete remission patients, the median OS for PCI+ and PCI- patients was 20.0 and 19.0 months, respectively (p \u3e 0.05, nonsignificant). The median disease-free survival was 14.7 and 10.0 months, respectively (p \u3c 0.05). The difference in the mean Q-TWiST survival was significant (p \u3c 0.01). The mean marginal cost was $18,834/PCI+ patient and$17,885/PCI- patient (p \u3e 0.05, nonsignificant). The cost-effectiveness ratio was $70/mo of incremental OS if u(tox) and u(rel) (the utility coefficients to reflect the value of time in health states of toxicity and relapse) were assumed to be 1.0. CONCLUSION: PCI is a cost-effective treatment that improves the quality-of-life-adjusted survival for patients with a complete remission of SCLC