No description available.

No description available.

No description available.

No description available.

Maize production in short-season environments has at least two critical problems. Firstly, maize grown in short-season areas has lower leaf area indices (LAI) than maize grown in long season areas, due to shorter plant stature and less time for development, which results in reduced leaf number and size. Secondly, in very short-season areas the seasonal thermal-time available may be insufficient to mature grain of current maize hybrids. Therefore development of maize types that accumulate leaf area and mature quickly would increase production of maize in mid- to short-season areas. The leafy (Lfy1) and reduced-stature (rd1) genes make contributions to this end. However, these two genes have not previously been combined. From 1991 to 1993, field experiments were conducted to evaluate the leafy reduced-stature (LRS) inbred lines and hybrids for yield, maturity times and morphological traits, at different planting densities and patterns in Montreal and Ottawa. LRS maize inbred lines showed the most rapid silk extrusion, optimum leaf area development, and rapid growth of the first ear, the highest yield per unit leaf area, and the closest synchronization of pollen shed and silk extrusion at high plant population densities. LRS maize hybrids had the most rapid leaf development, longest grain filling period, lowest grain moisture content at harvest, and highest harvest index. Therefore LRS hybrids should allow an extension into shorter season areas where it can not now be successfully cultivated, and may increase yields in mid- to short season areas where maize is now produced.

This thesis focuses on the development of a novel hybrid linear actuator (HLA). The research includes the optimal design, the particular fabrication, and the experimental validation. The principle of the HLA is based on the integration of the mechanisms of the solenoid actuator and the voice coil actuator. Such integration is achieved by a magnetic circuit consisting of a magnetic flux orientator, a permanent magnet, a composite shell, and a special coil. The HLA is capable of having a high repelling force at one end and a high attractive force at another end. A step-optimization technique is developed and used to determine the key parameters of the HLA, with the aid of sweeping functions in finite element analysis. Moreover, a single-pulse power supply is specially designed and prototyped for driving the HLA. The performance of the HLA is systematically characterized by simulations and experiments.

This thesis focuses on the development of a novel hybrid linear actuator (HLA). The research includes the optimal design, the particular fabrication, and the experimental validation. The principle of the HLA is based on the integration of the mechanisms of the solenoid actuator and the voice coil actuator. Such integration is achieved by a magnetic circuit consisting of a magnetic flux orientator, a permanent magnet, a composite shell, and a special coil. The HLA is capable of having a high repelling force at one end and a high attractive force at another end. A step-optimization technique is developed and used to determine the key parameters of the HLA, with the aid of sweeping functions in finite element analysis. Moreover, a single-pulse power supply is specially designed and prototyped for driving the HLA. The performance of the HLA is systematically characterized by simulations and experiments.

The majority of vehicles over the near term will rely on petroleum, with electric vehicles poised to take over a significant market share of new light duty vehicles in the near future. The proposed Auxiliary Drive Device (ADD) instantly provides hybridization and electrification of an existing fossil fuel vehicle. The purpose is to contribute torque to increase fuel economy and to compensate for the load born by a towing vehicle to reduce the engine size. The ADD is simulated, built and tested for the first time in a towing vehicle configuration. A sensor integrated mechanism is used to measure the force of the trailer load onto the towing vehicle. A test bench platform verifies controls on a push plate in a force sensor feedback control loop configuration. In addition, a scaled prototype provides experimental data to verify mathematical models developed for the ADD. It is found that this new concept provides performance gains and fuel economy savings in a towing configuration.

There is a lack of available technology to make small-scale power from biomass cost effectively. The proposed Hybrid Brayton cycle is an indirectly heated Brayton cycle with evaporative cooling for combined heat and power generation. It converts a direct fired microturbine to an indirectly heated power system. The Hybrid Brayton cycle offers a flexible biomass power generation platform in the 30 to 250 kWe range, achieving competitive efficiencies and advantages compared to other systems of similar power level. This cycle is designed to be implemented in remote and off-grids communities, small industries and net-zero communities, where local biomass feedstock is sustainably available. This proposed platform keeps operator qualifications to a minimum. In an effort to validate this new power cycle, a 30 kWe experimental facility was developed and initial commission phases performed. This facility purpose is to validate numerical model predictions and is used for optimization. The facility is described and results of the commissioning tests are reported with various problems encountered, solutions implemented and recommendations proposed. The thermodynamic model of the Hybrid Brayton cycle is also implemented in the MatLAB environment, incorporating experimental findings and new properties for humidified air at high temperatures. The MatLAB model confirms that an indirect fired Brayton cycle with evaporative cooling could be a viable approach for small scale distributed power generation using biomass. Additional experimental data of humidified air at elevated temperatures would provide more certainty in property predictions. The MatLAB model provides a modeling tool to allow resolving the issues identified during the commissioning of the test facility and offers alternatives to optimize various design configurations, implementing the most up to date property correlations for humidified air at elevated temperatures.

The majority of vehicles over the near term will rely on petroleum, with electric vehicles poised to take over a significant market share of new light duty vehicles in the near future. The proposed Auxiliary Drive Device (ADD) instantly provides hybridization and electrification of an existing fossil fuel vehicle. The purpose is to contribute torque to increase fuel economy and to compensate for the load born by a towing vehicle to reduce the engine size. The ADD is simulated, built and tested for the first time in a towing vehicle configuration. A sensor integrated mechanism is used to measure the force of the trailer load onto the towing vehicle. A test bench platform verifies controls on a push plate in a force sensor feedback control loop configuration. In addition, a scaled prototype provides experimental data to verify mathematical models developed for the ADD. It is found that this new concept provides performance gains and fuel economy savings in a towing configuration.