Global ETD Search

1	Establishing a Coastal Protection and Planning System in Taiwan Yu, Meng-Jiuan 05 September 2011 (has links) In the last few decades, academic and institutions advanced in coastal research in Europe and America have rigorously engaged in developing numerical models for coastal wave hydrodynamic simulations. The notable products include MIKE21 from DHI in Denmark, CEDAS (with GENESIS and SBEACH) from Veri-Tech in the United States, and the SMC from University of Cantabria in Spain. Among them, the Spanish Coastal Modeling System (SMC) is the only integrated package for coastal planning and modeling. With a unique preprocess module which pre-stores the bathymetry and wave data, the SMC provides a user-friendly interface directly using the screen display for a series of coastal planning and design applications which comprise artificial nourishment with headland-bay beach, breakwater construction and extension, and dredging of navigation channel etc., as well as the usual wave-current simulation for countermeasures in coastal protection and disaster mitigation. Despite the availability of several numerical programs for wave-current simulations and beach changes that have been developed by the coastal professional in Taiwan, and the continuous effort of the Water Resources Agency, Ministry of Economic Affairs to establish a national coastal database, it is imperative to develop/setup an integrated bathymetry-hydrodynamics-protection system, such as the Spanish SMC, as the key element in the national platform for coastal planning and modeling. This dissertation first describes the coastal environment in Taiwan, major causes for shoreline evolution and then reviews the history of shore protection since 1970s, together with the current prospective for coastal environment and strategies to sustain the natural shoreline ratio. To accomplish these goals, the Water Resources Agency has endeavored to implement artificial nourishment with headland-bay beaches, in order to raise the ratio of natural shoreline, in addition to establish a national coastal planning and simulation platform. As a response to this call for eco-engineering approach, we recommend that headland-bay beach in static equilibrium be adopted for mitigating coastal erosion, beach restoration and creation of recreational beaches, which can be designed directly on the screen using the empirical bay shape equation in conjunction with the SMC. Based on the framework of the Spanish SMC, this writer has successfully attempted the preliminary pre-process module of Baco (bathymetry) and Odin (wave climate) for Taiwan, using data from digitized nautical charts, nearshore depth surveys, and long-term wave observation results around Taiwan from the International Comprehensive Ocean-Atmosphere Data Set (ICOADS). The effort generates the first version of SMC in Taiwan. Having pre-stored the bathymetry and wave data for Dapeng bay in Pingtung County and Sizihwan Bay in Kaohsiung City, a series of coastal planning and modeling procedures for these two model sites are demonstrated in this dissertation, including a series of calculations of wave-current distribution for monsoon and storm waves, as well as planning of bay beach using artificial nourishment. Upon executing the Taiwanese version of SMC introduced in this dissertation, the modeling results can be applied to assist the planners and decision makers in comprehending the coastal environment, devising a feasible shore protection strategy, and promoting an earlier accomplishment of the so-called ¡ugeo-engineering ¡u in our country. Finally, the writer also wishes the outcome of this study could help relevant government agency to accomplish the prospective of sustainable coastal development upon implementing the strategies of establishing an appropriate coastal planning platform and promoting a systematic approach for coastal planning and design, as revealed in the "Sustainable Regeneration of Coastal Environment Project (98 ~ 103 fiscal year)". wave-current simulation SMC Shore protection Coastal planning platform Beach nourishment Headland-bay beach in static equilibrium
2	Nelineární obvody s proudovými operačními zesilovači / Nonlinear Circuits with Current Operational Amplifiers Rudolf, Jaroslav January 2009 (has links) This master’s thesis is about replace voltage feedback operation amplifiers (VFOA) by current operational amplifiers (COA), current conveyors and current followers (CF). In introduction are mentioned word or two about operational amplifiers and their basic circuit such as invert and non-invert amplifier and there are described formulas for calculation gain. In another chapter is described COA, his properties and advantages compared to VFOA. Next there are described basic circuits of current conveyors. Follows chapter where is described replace VFOA by COA and conversion between them. In another part is at first deal with models of COA and CF in simulating program and then replace VFOA by COA. There are some simple circuits for example precision rectifiers and function generators and their simulations before and after replace VFOA by COA. In full-wave rectifier with current conveyors is made detailed simulation with some input voltages and frequencies. In last chapter is detailed described multi-mode rectifier with current follower. There is table witch described all modes of rectifier. For example voltage mode, current mode and mixed mode with half- or full-wave rectifier. There are simulations for all modes. Primarily are made detailed simulations voltage and current mode. In another part of this chapter is made measurement voltage and current mode. There are measured functions as half- and full-wave rectifier. There are described parameters of rectifier from measured values. In the end are these values compared with values from simulations.
3	Modeling Of Dust Loaded Electrical Characteristics And Collection Efficiency Of Industrial Electrostatic Precipitators Jayan, M V 07 1900 (has links) With the increase in population and industrial growth, the need for power has increased manifold. A major share of India’s power generation is coal-based generation. Thermal power generation through coal combustion produces minute particles of ash that causes serious environmental problems. Most of the thermal power stations in India use bituminous coal and produce large quantities of fly ash. Fly ash is produced primarily by thermal power plants and, to a lesser extent, by cement and steel plants and railways. This poses problems in the form of land use, health hazards, and environmental dangers. Today the fly ash from thermal power plants is utilized to make cement. Cement industry needs fly ash with more fine particles. If these fine particles (of diameter in micro-meter range) are left out to atmosphere, it will be easily breathed into lungs, creating health hazard to human as well as animal life. If properly collected, it forms a valuable by product. Hence collecting fly ash is important to reduce pollution and also to increase revenue. Even though there are many devices like cyclones, fabric filters etc. the Electrostatic Precipitator (ESP) is the most efficient device to capture the fly ash. It is at this juncture a need for such a simple ESP model was felt to facilitate prediction of the V-I characteristics of dust loaded precipitators, be it cement dust or fly ash. Given the fact that 99% of Indian ESPs are operated under DC energization and most of them are running inefficiently due to lack of proper diagnostic tools and also due to lack of interest to invest on an ESP. In such circumstances, the free availability of a simple model that combines the V-I curves with collection efficiency serves to improve the ESP performance in our Indian industries. In an ESP Voltage-Current (V-I) characteristics are used to diagnose any electrical problems occurring in it. Mathematical model of V-I characteristics under clean air and dust laden conditions will be helpful in diagnosing the ESP problems as well as in designing the ESP. The model will also indirectly reflect upon the collection efficiency of the ESP. The collection efficiency should be as high as possible not only to prevent pollution but also to collect maximum fly ash which is a valuable by-product. The modeling of collection efficiency will help the industries to design a new precipitator as well as to improve the performance the collection efficiency to meet the changing restrictions set by the government to reduce pollution. In this thesis a mathematical model of ESP based on Finite Difference Method is developed. The modeling is done in three sections. 1. Simulation of clean air V-I characteristics. 2. Simulation of dust laden V-I characteristics. 3. Simulation of collection efficiency. Simulation of clean air V-I characteristics is done by iteratively solving the Poisson’s equation and current continuity equation, using FDM in one quarter region of the ESP. Just by introducing the effect of particle charge into this solution the dust laden V-I characteristics are simulated. Finally, the collection efficiency is calculated using average charge density at the plates obtained from the above solution. The developed model is validated at first against published experimental and simulated data and then, with the data obtained through conduction of experiments, by the author, on commercial precipitators situated at a thermal power station and a cement plant, in India. The thesis discusses in detail these theoretical and experimental studies. Electrostatic Equipments Electrostatic Machinery Precipitators Electrostatic Precipitator Electrical Engineering
4	Communicating science : developing an exhibit with scientists and educators Lemagie, Emily 28 October 2011 (has links) Outreach is a small, but significant component to modern research. Developing an exhibit for public display can be an effective way to communicate science to broad audiences, although it may be a less familiar method to scientists than writing papers or giving presentations. I outline the process of developing an interactive exhibit for outreach, and evaluate and discuss the effectiveness of a computer exhibit designed to communicate estuary currents and scientific modeling using Olympia Oyster restoration in the Yaquina Bay estuary as a theme. I summarize the results of this project in three primary recommendations: 1) exhibit developers should be deliberate in the decision to use a computer and only select this media if it is determined to be the best for communicating exhibit learning outcomes, 2) the design of visualizations to convey research results should be carefully modified from their scientific forms to best meet the exhibit learning outcomes and expectations of the exhibit audience, and 3) scientists should play an integral role in the development of scientific content-based exhibits, but their expertise, and the range of expertise from other members of the exhibit development team, should be strategically utilized. / Graduation date: 2012 Exhibit Exhibit Development Exhibit Design Education Marine Education Marine Interpretation Science Interpretation Informal Science Environmental Interpretation Environmental Outreach Science Education Communicating Science Estuary Interpretation Communication Outreach Science Outreach Free-Choice Learning Informal Education Informal Science Estuary Education Museum Exhibit Interactive Kiosk Computer Exhibit Computer Interface Interactive Touchscreen Kiosk Marine Science Exhibit Computer Display Interactive Exhibit Interactive Visualization Current Simulation Scientific Model Numerical Model Estuary Science Visitor Center Marine Science Center Visitor Behavior Museum Hatfield Marine Science Center Science Center Emily Lemagie Oregon Sea Grant Education Kiosk Educational Kiosk Computer Kiosk Science Communication Touchscreen Interface Backwards Design Tidulator Museum exhibits -- Oregon -- Newport Hatfield Marine Science Center

1

Page generated in 0.1753 seconds