Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Engineering
Investigation Of Digital Pump/Motor Control Strategies, Farid El Breidi
Investigation Of Digital Pump/Motor Control Strategies, Farid El Breidi
Open Access Dissertations
A pump is the heart of fluid power systems, it has a significant impact on the efficiency of many fluid power systems. Motors are the most common rotary actuators in fluid power systems. State-of-the-art pump/motor units can achieve efficiencies higher than 90% when operating at maximum displacement; however, as the displacement drops, the efficiency of these units drops to below 50%. A new digital pump/motor design aims at increasing these efficiencies by utilizing two electrically controlled high speed on/off valves per displacement chamber; these valves provide the ability to achieve variable displacement and allow freedom in choosing operating strategies. Such …
High-Power Microwave/ Radio-Frequency Components, Circuits, And Subsystems For Next-Generation Wireless Radio Front-Ends, Kenle Chen
Open Access Dissertations
As the wireless communication systems evolve toward the future generation, intelligence will be the main signature/trend, well known as the concepts of cognitive and software-defined radios which offer ultimate data transmission speed, spectrum access, and user capacity. During this evolution, the human society may experience another round of `information revolution'. However, one of the major bottlenecks of this promotion lies in hardware realization, since all the aforementioned intelligent systems are required to cover a broad frequency range to support multiple communication bands and dissimilar standards. As the essential part of the hardware, power amplifiers (PAs) capable of operating over a …
Effect Of Building Morphology On Energy And Structural Performance Of High-Rise Office Buildings, Mohamed Krem
Effect Of Building Morphology On Energy And Structural Performance Of High-Rise Office Buildings, Mohamed Krem
Open Access Dissertations
The civil engineering and architectural communities are highly focused, these days, on designing buildings that maximize utilization of energy available from natural resources. This dissertation presents a quantitative study of the effect of high-rise office building morphology on energy and structural performances for the major climates. The parameters of the building morphologies are varied - the building footprint shape, the placement of the structural core/walls, and the building orientation. The energy analysis is performed using Autodesk Ecotect Analysis 2011; while using SAP2000 for the structure analysis and design. The key observations are: 1) the building morphology has a significant effect …