HARVEST
University of Saskatchewan's Repository for Research, Scholarship, and Artistic Work
Welcome to HARVEST, the repository for research, scholarship, and artistic work created by the University of Saskatchewan community. Browse our collections below or find out more and submit your work.
Communities in HARVEST
Select a community to browse its collections.
Recent Submissions
Application of Omics for the Assessment of Response of Early-Life Stage Salmonids to Emerging Chemical Stressors
(2024-10-10) Ankley, Phillip John; Brinkmann, Markus; Giesy, John; Hecker, Markus; Hogan, Natacha; Links, Matt; Laprairie, Robert; Martyniuk, Christopher
The abstract of this item is unavailable due to an embargo.
HUMAN-WOLF CONFLICT AND COEXISTENCE IN THE PACIFIC RIM NATIONAL PARK RESERVE REGION, NUU-CHAH-NULTH TRADITIONAL TERRITORY, VANCOUVER ISLAND, BRITISH COLUMBIA
(2024-10-10) Doney, Ethan; Clark, Douglas; Bradford, Lori; Reed, Maureen; Brook, Ryan; Frank, Beatrice; Sandstrom, Camilla
Protected areas situated at the urban-wilderness interface present unique wildlife conservation opportunities and challenges. Pacific Rim National Park Reserve (PRNPR) occupies the traditional lands of nine First Nations and adjoins two tourist communities on the southwest coast of Vancouver Island. This geography presents a complex task of balancing rights of First Nation communities, residents, and park visitors, while upholding the ecological integrity mandate of the Parks Canada Agency. Human-wolf interactions typify these challenges because of re-established wolf populations, increased residential development, and perpetuation of behaviors by residents and visitors that habituate wolves and puts wolves’ survival at risk. The objectives of this research were to: (1) define “conflict” and “coexistence”, and their influencing factors, (2) better understand local residents’ and visitors’ sentiments regarding wolves and their management, (3) characterize ways that PRNPR and partner Nuu-chah-nulth First Nations can weave Nuu-chah-nulth Knowledge and local best practices into conflict-mitigation and long-term coexistence strategies, and (4) identify and present a human-wolf coexistence framework that foster ongoing collaboration and relationship building. These objectives were addressed using a mixed-methods approach involving semi-structured interviews (n=32) and a collaborative workshop. Throughout this dissertation, I share important insights across all these objectives, some of which include: (1) co-produced definitions and parameters of conflict and coexistence (objective 1, 2, and 3), (2) unique findings showing the high level of tolerance and excitement for wolves, but that conflicts are primarily being led by pro-wolf people and groups (objectives 1 and 2), and (3) a co-identified path toward more effective cross-cultural collaboration in state-led efforts around human-wildlife interactions (objectives 3 and 4). Results will inform future efforts on human-wolf coexistence and relationship building among Parks Canada, First Nations, and rights- and stakeholder groups.
THEORETICAL AND EXPERIMENTAL INVESTIGATIONS OF THE CROSSMAGNETIZING PHENOMENON IN SATURATED SYNCHRONOUS MACHINES
(1989-10) Wu, Jiwei; El-Serafi, A.M.
In recent studies of the saturation effect in synchronous machines, there has been an increasing recognization of the important role of the magnetic coupling between the direct- and quadrature-axis (the cross-magnetizing phenomenon) in the analysis of saturated synchronous machines. In this context, it has been noticed that there are large discrepancies between their measured and calculated steady-state characteristics. This has been attributed to ignoring this magnetic coupling effect in the steady-state, two-axis (direct and quadrature-axis) frame models of these machines.
This thesis investigates the various approaches of representing saturation in the two-axis frame models of synchronous machines. In particular, the concept of the magnetic coupling between the two axes of synchronous machines is demonstrated. A modified two-axis frame model, in which the effect of the cross-magnetizing phenomenon is included, is used in the investigations of the steady-state performances of four synchronous machines of various designs. The active and reactive power/load angle curves of these machines are obtained experimentally and analytically. The accuracy and the universality of this new model and the importance of the inclusion of the cross-magnetizing effect in such a model are thus verified.
The thesis also presents some new techniques which have been developed through the course of the research work. For determining the various saturation factors of salient-pole synchronous machines, a method for calculating the open-circuit characteristic curves in the intermediate axes of these machines is developed. This method can also be applied in calculating the cross-magnetizing effect of the salient-pole synchronous machines. Moreover, an accurate method is proposed for determining the armature leakage reactance of synchronous machines, which is needed for the determination of the machine per unit field current
AN ULTRASONIC LINKAGE SYSTEM FOR A MASTER-SLAVE TRACTOR GUIDANCE SYSTEM
(1974) Wu, Siu Keung; Krause, A. E.
An ultrasonic information linkage system was developed which can measure continuously and automatically the relative position and orientation of two slowly moving vehicles on a plane. This system was primarily designed to link up an automatic tractor to an operator controlled tractor in a master-slave mode so as to double the productivity of a skillfull worker in agriculture.
A laboratory prototype of the linkage system was constructed and tested which confirmed the feasibility of employing the proposed system in a master-slave tractor guidance system.
A STUDY OF THE PLL DEMODULATOR FOR E-SCATTER NORTHERN COMMUNICATIONS
(1968-09) Woo, Billy Yee; Michalenko, A.
The design, construction, and testing of a narrow-band FM system for VHF E-scatter communications between Rankin Inlet, N.W.T.
and Park Site, Saskatchewan are described._ A review of earlier studies in E-scatter communications is made and some design considerations based on these studies are given. Results of laboratory tests made on the phase-locked loop demodulator prior to field installation of the equipment are shown and performance evaluations are made to determine the preferred, if not optimum, demodulator parameter values. Field test records from the E-scatter communications path are shown and an evaluation of system performance is made. It is concluded that 90 percent -success can be. obtained on a 915 mile E-scatter link with the receiving system studied and a transmitter output power of 320 watts. The information rate would be 10 Hz with a transmission bandwidth of about 500 Hz. Alternatively, the game success may be obtained with an extended range phase-locked loop demodulator and a transmitter output power of about 80 watts.
A NARROW-BAND PHASELOCK RECEIVER FOR NORTHERN COMMUNICATION
(1966-05) Wohlberg, Donald Bernard; Wacker, A. G.
A low-power, narrow-band VHF ionospheric forward-scatter communication link has been proposed to provide reliable communication in northern latitudes. Conflicting results produced by two ;previous experiments concerned with establishing the feasibility of such a system have suggested that a more detailed analysis of the phaselock receiver used in these experiments be undertaken.
This thesis is concerned with the analysis of the phaselock receiver with special attention focused on the random Doppler shifts introduced by the ionosphere, which are the limiting factors in the design of such a system. A model is developed for the particular system under study. The analysis of the non-linear model is achieved by a quasi-linearization method. Computer solutions are resorted to where necessary. Threshold is considered for the second-order and first-order systems. The first-order system has advantages at low S/N ratios. It is also shown that a first-order system has a better sensitivity when receiving a Doppler shifted
signal. To implement a first-order system high frequency stability is necessary. In addition, detailed information about Doppler shifted is desired, and a highly stable system is necessary for this purpose. Frequency stability was introduced to the system.
MODELING OF SHIELDED MICROSTRIP TRANSMISSION LINES
(1996) Wells, Garnet Stuart; Pramanick, Protap
Microstrip lines are widely used not only in microwave circuits, but also in very large scale integration (VLSI) and high frequency circuit boards. Initially microstrip lines were analyzed mainly in the frequency domain, but now time domain analysis is also becoming a subject of prime importance. Time domain analysis data is relevant in determining the behavior of many microwave and VLSI circuits. Full wave time domain analysis is usually not practical due to computer time and memory requirements. Therefor, time domain analysis is usually carried out via frequency domain analysis and the inverse Fourier transform. Frequency domain analysis can be very accurate when a stationary model for the dispersive behavior of a microstrip line is utilized. This method has been successfully employed in time domain analysis of various forms of open microstrip lines.
Since most microwave integrated circuits (MIC) and VLSI packagings have closed structures, an efficient and fast time domain analysis of such structures requires a model which describes the dispersive behavior of a shielded microstrip line. However, unlike the case for an unshielded microstrip line, no dispersion model exists for the shielded microstrip line.
GENERATING CAPACITY RELIABILITY STUDIES OF SINGLE AND INTERCONNECTED SYSTEMS USING FREQUENCY AND DURATION ANALYSIS
(1980-03) Wee, Chaw Lam; Billington, R.
Frequency and Duration analysis provides a practical method for reliability evaluation of generation system configurations. The primary indices of interest are the cumulative probability and frequency of a load loss situation. This approach uses the individual generating unit mean failure and repair rates in addition to the forced outage probability values and therefore the developed indices are sensitive to all of these values.
This thesis illustrates the inclusion of derating levels of large generating units in the capacity models and how this approach can be extended to the analysis of interconnected systems. Different load models and the effect of load forecast uncertainty are examined. The -thesis further considers the effect of transmission constraints on the generation system.
A general computer program which includes all these considerations is presented. This program has been used to conduct a comprehensive set of studies on the recently published IEEE Reliability Test System. These studies are outlined in the thesis.
A Centralized, Unidirectional Wireless Communication System for Monitoring Sensor
(2003) Wang, Yanyu; Daku, Brian
There is a significant advantage in using a wireless wensor network in a mining environment because of the reduced installation and maintenance costs. The application considered here is the monitoring of the roof movement in underground mine rooms, which is used to provide a warning of a potential ceiling collapse. Since cables in the system are difficult to install, remove and are frequently damaged, the use of the wired monitoring system is limited in underground mines. Those problems can be solved by using a wireless sensor network to replace the wired system.
The focus of this research is to design and develop a wireless communication system that can be used to implement a wireless sensor network for monitoring roof movement in one mine room. Since a large number of portable, battery operated sensors are used, simple system architecture and low power consumption are required. Based on these criteria, the wireless communication system uses a unidirectional, centralized architecture combined with periodic monitoring to perform the monitoring task. The proposed system contains multiple Transmitter Units and one Receiver Unit. A protocol that is used to manage channel access is defined. The probability of collision for this protocol is analyzed and simulated. The prototype of the wireless communication system is implemented, which consists of a Transmitter Unit and a Receiver Unit. The protocols are implemented using reprogrammable devices to provide easy reconfiguration and update. The system prototype is tested in a laboratory, and the test results show that the defined data frame, containing a digitized input voltage, is transmitted and received correctly.
Catalytic Oxidation of VOCs in Air Using Vacuum Ultraviolet Irradiation
(2024-10-09) Payan, Amir; Baik, Oon-Doo; Abdelrasoul, Amira; Chen, Ning; Kelly, Timothy; Mehrvar , Mehrab
The abstract of this item is unavailable due to an embargo.