[en] Fluctuations of the F-region electron density in the gravity wave period range are monitored using the Arecibo incoherent scatter radar. Seen in several sets of these power spectra are two dips in the power level one of which is shown to be consistent with the large attenuation of gravity waves anticipated near the Brunt-Vaisala frequency. The second dip which is strongly altitude dependent is associated with the no response condition when the gravity wave vector is perpendicular to the earth's magnetic field lines. The height dependence of the derivative of the zero order logarithmic electron density. In several sets of power spectra corresponding to differnt time periods of the day, spectral peaks consistently present at a nearly constant frequency over the entire altitude range of the experiment are observed. These peaks are taken as the ionospheric response to individual, quasi-sinusoidal gravity waves. The time averaged, altitude dependent magnitude squared of each of these perturbations is derived from the power spectra. Complementary phase information at the corresponding frequency is obtained from the original time series. From this magnitude and phase of the ionospheric perturbation,the wave parameters of a causative gravity wave are found in a nonlinear least squares sense. This is done through the equations of continuity and motion for the ionization. These wave parameters are compared with a dispersion relation for gravity waves. Good agreement is found for the real part or phase portion of the vertical wave number except at altitudes above the F-region peak. The imaginary part of the wave number or the attentuation factor showed poorer agreement with the dispersion relation, since this quantity is very sensitive to parameters of the model atmosphere

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[en] Fault trees and event trees have been widely accepted as the modeling strategy to perform Probabilistic Risk Assessment (PRA). However, there are several limitations associated with fault tree/event tree modeling. These include 1. It only considers binary events; 2. It assumes independence among basic events; and 3. It does not consider timing sequence of basic events. This thesis investigates Petri net modeling as a potential alternative for PRA modeling. Petri nets have mainly been used as a simulation tool for queuing and network systems. However, it has been suggested that they could also model failure scenarios, and thus could be a potential modeling strategy for PRA. In this thesis, the transformations required to model logic gates in a fault tree by Petri nets are explored. The gap between fault tree analysis and Petri net analysis is bridged through gate equivalency analysis. Methods for qualitative and quantitative analysis for Petri nets are presented. Techniques are developed and implemented to revise and tailor traditional Petri net modeling for system failure analysis. The airlock system and the maintenance cooling system of a CANada Deuterium Uranium (CANDU) reactor are used as case studies to demonstrate Petri nets ability to model system failure and provide a structured approach for qualitative and quantitative analysis. The minimal cutsets and the probability of the airlock system failing to maintain the pressure boundary are obtained. Furthermore, the case study is extended to non-coherent system analysis due to system maintenance. (author)

No abstract available

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[en] The D-Zero silicon trough is segmented into two half troughs. Loading to the Central Fiber Tracker Barrel 1 is at both ends and near Z = 0. The loading near Z = 0 is thought to be 4 lbs at 4 points. The point locations are at +/-45 degrees for each half trough on each side of Z = O. An additional support at Z = O is required to prevent beam sag and out of round distortions to the CFT Barrel 1. An additional joining washer will be attached between barrels 1 and 2 at Z = 0. Also a support ring will be attached to the inner diameter of barrel 1 to further help in out of round distortions. Details of the washer and loading are modeled using ANSYS.

[en] The major modification to the D0 detector for the next physics collider run is the upgrade of the central tracking system. The first component to be installed will be the solenoid magnet, with the central pre-shower attached. This engineering note is directed to the installation of the solenoid magnet and the equipment needed to accomplish this task. As part of the installation process, the main detector must undergo a change in position of one of its major components, namely the South End Calorimeter (SEC). This calorimeter must be completely decoupled from the main detector, i.e. all cabling and cryo lines removed. The equipment used for installing all calorimeters (bridge and support structures) will be put into position and the calorimeter (SEC) will be pulled off of the detector center beam and parked on the south sidewalk of the D0 Assembly Hall. The necessary cryo lines will re-connected in order to keep the cryostat cold. This calorimeter will remain here during the greater portion of the upgrade reconfiguration schedule. When this task is finished, the old central tracking system and its mounts will be removed from the bore of the Central Calorimeter (CC). The main detector is now ready to receive the new tracking system, starting with the solenoid magnet.

[en] The Nuclear Waste Management Organization (NWMO) is presently in a multi-year process of identifying a safe site for a deep geological repository for Canada’s used nuclear fuel in an area with informed and willing hosts (NWMO 2010). This is similar to plans in other countries with nuclear power programs, including Finland, Sweden, France and Switzerland, which have sites for their deep geological repositories for nuclear fuel waste. The Government of Canada selected the deep geologic repository approach in 2007, and assigned the NWMO with the task of siting, building and operating this repository. The NWMO has responded with a siting program that includes discussions and planning with communities, and conducting technical and social studies. Early assessments were summarized in a series of reports available on the NWMO website at www.nwmo.ca/studyareas. These discussions and studies have identified two candidate siting areas – one in northwestern Ontario and one in southern Ontario. This report focuses on the Revell Site in the Wabigoon Lake Ojibway Nation (WLON) – Ignace area. This site is located approximately 21 km southeast of the Wabigoon Lake Ojibway Nation and 43 km northwest of the Town of Ignace. The site is on the Canadian Shield, about 260 km north of Lake Superior. (author)

[en] The Nuclear Waste Management Organization (NWMO) is presently in a multi-year process of identifying a safe site for a deep geological repository for Canada’s used nuclear fuel in an area with informed and willing hosts (NWMO 2010). This is similar to plans in other countries with nuclear power programs, including Finland, Sweden, France and Switzerland, which have sites for their deep geological repositories for nuclear fuel waste. The Government of Canada selected the deep geological repository approach in 2007, and assigned the NWMO with the task of siting, building and operating this repository. The NWMO has responded with a siting program that includes discussions and planning with communities, and conducting technical and social studies. Early assessments were summarized in a series of reports available on the NWMO website at http://www.nwmo.ca/Site-selection. These discussions and studies have identified two candidate siting areas – one in northwestern Ontario and one in southern Ontario. This report focuses on the site in the Saugeen Ojibway Nation (SON) – South Bruce area. This South Bruce Site is located approximately 5 km northwest of Teeswater in the Municipality of South Bruce. It is about 30 km inland from Lake Huron. (author)

[en] The propagation of ion acoustic wave (IAW) in a double-electron-temperature plasma is investigated both experimentally and theoretically. It is found that the presence of even a small fraction of the lower-electron-temperature component can dominate the behavior of the waves. The results have important implications both for the use of IAW as a diagnostic tool for measuring electron temperature and for the interpretation of turbulent IAW spectra. (auth)