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A remote laboratory for testing microelectronic circuits on silicon wafersMohtar, Aaron January 2009 (has links)
This thesis explores the technical feasibilty of creating a remote laboratory in the field of microelectronics fabrication. It also includes the evaluation of the developed laboratory as a teaching tool. / PhDElectronicEngineering
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Otahuhu B Power Station condenser in-leakage analysis and condensate monitoring system : a thesis presented in partial fulfilment of the requirements for the degree of Master of Engineering in Electronics Engineering at Massey University, Wellington, New ZealandZhang, Heng January 2008 (has links)
Considerable ongoing risk of condenser in-leakage exists at Otahuhu B (OTB) Power Station. The condenser cooling water used at OTB station is corrosive brackish water with exceedingly high sodium and chloride concentrations. Significant signs of corrosion inside the condenser have been found recently. In the event of condenser in-leakage, the salt contaminants in the cooling water will directly enter the Heat Recovery Steam Generator (HRSG) with the potential for significant and costly damage resulting in a long plant outage. A dynamic mathematical model was developed in the thesis to analyse the consequences of condenser in-leakage at OTB station. The analysis results show that the tolerance of the condenser to any leakage of cooling water is almost zero. Because the existing condensate monitoring system is not designed to detect contamination in this time frame, a new fast response system is required to detect condenser in-leakage immediately. A new dedicated fast response condensate monitoring system has been engineered and installed at OTB station as a part of the project scope. The new system dramatically reduces the response time to condenser in-leakage events. Critical instruments utilise multiple redundancy schemes to enhance the availability and reliability of the system. In addition, action level voting, timing, and alarming has been automated to assist operators in making correct decisions. The new condensate monitoring system is presently fully functional. The project has successfully achieved the objective of controlling the risk of condenser in-leakage events and minimising damage and negative effects on the plant.
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Otahuhu B Power Station condenser in-leakage analysis and condensate monitoring system : a thesis presented in partial fulfilment of the requirements for the degree of Master of Engineering in Electronics Engineering at Massey University, Wellington, New ZealandZhang, Heng January 2008 (has links)
Considerable ongoing risk of condenser in-leakage exists at Otahuhu B (OTB) Power Station. The condenser cooling water used at OTB station is corrosive brackish water with exceedingly high sodium and chloride concentrations. Significant signs of corrosion inside the condenser have been found recently. In the event of condenser in-leakage, the salt contaminants in the cooling water will directly enter the Heat Recovery Steam Generator (HRSG) with the potential for significant and costly damage resulting in a long plant outage. A dynamic mathematical model was developed in the thesis to analyse the consequences of condenser in-leakage at OTB station. The analysis results show that the tolerance of the condenser to any leakage of cooling water is almost zero. Because the existing condensate monitoring system is not designed to detect contamination in this time frame, a new fast response system is required to detect condenser in-leakage immediately. A new dedicated fast response condensate monitoring system has been engineered and installed at OTB station as a part of the project scope. The new system dramatically reduces the response time to condenser in-leakage events. Critical instruments utilise multiple redundancy schemes to enhance the availability and reliability of the system. In addition, action level voting, timing, and alarming has been automated to assist operators in making correct decisions. The new condensate monitoring system is presently fully functional. The project has successfully achieved the objective of controlling the risk of condenser in-leakage events and minimising damage and negative effects on the plant.
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Otahuhu B Power Station condenser in-leakage analysis and condensate monitoring system : a thesis presented in partial fulfilment of the requirements for the degree of Master of Engineering in Electronics Engineering at Massey University, Wellington, New ZealandZhang, Heng January 2008 (has links)
Considerable ongoing risk of condenser in-leakage exists at Otahuhu B (OTB) Power Station. The condenser cooling water used at OTB station is corrosive brackish water with exceedingly high sodium and chloride concentrations. Significant signs of corrosion inside the condenser have been found recently. In the event of condenser in-leakage, the salt contaminants in the cooling water will directly enter the Heat Recovery Steam Generator (HRSG) with the potential for significant and costly damage resulting in a long plant outage. A dynamic mathematical model was developed in the thesis to analyse the consequences of condenser in-leakage at OTB station. The analysis results show that the tolerance of the condenser to any leakage of cooling water is almost zero. Because the existing condensate monitoring system is not designed to detect contamination in this time frame, a new fast response system is required to detect condenser in-leakage immediately. A new dedicated fast response condensate monitoring system has been engineered and installed at OTB station as a part of the project scope. The new system dramatically reduces the response time to condenser in-leakage events. Critical instruments utilise multiple redundancy schemes to enhance the availability and reliability of the system. In addition, action level voting, timing, and alarming has been automated to assist operators in making correct decisions. The new condensate monitoring system is presently fully functional. The project has successfully achieved the objective of controlling the risk of condenser in-leakage events and minimising damage and negative effects on the plant.
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Wireless vehicle presence detection using self-harvested energy : a thesis in partial fulfilment of the requirements for the degree of Master of Engineering in Mechatronics, Massey University, Albany, New ZealandNoble, Frazer K. January 2009 (has links)
Rising from the “excess demand” modern societies and economies place on limited road resources, congestion causes increased vehicle emissions, decreases national efficiency, and wastes time (Downs, 2004). In order to minimise congestion’s impacts, traffic management systems gather traffic data and use it to implement efficient management algorithms (Downs, 2004). This dissertation’s purpose has been the development of a distributable vehicle presence detection sensor, which will wirelessly provide vehicle presence information in real time. To address the sensor’s wireless power requirements, the feasibility of self-powering the device via harvested energy has been investigated. Piezoelectric, electrostatic, and electromagnetic energy harvesting devices’ principles of operation and underlying theory has been investigated in detail and an overview presented alongside a literature review of previous vibration energy harvesting research. An electromagnetic energy harvesting device was designed, which consists of: a nylon reinforced rubber bladder, hydraulic piston, neodymium magnets, and wire-wound coil housing. Preliminary testing demonstrated a harvested energy between 100mJ and 205mJ per axle. This amount is able to be transferred to a 100O load when driven over at speeds between 10km/h and 50km/h. Combined with an embedded circuit, the energy harvester facilitated the development of a passive sensor, which is able to wirelessly transmit a vehicle’s presence signal to a host computer. The vehicle detected event is displayed via a graphical user interface. Energy harvesting’s ability to power the embedded circuit’s wireless transmission, demonstrated the feasibility of developing systems capable of harvesting energy from their environment and using it to power discrete electronic components. The ability to wirelessly transmit a vehicle’s presence facilitates the development of distributable traffic monitoring systems, allowing for remote traffic monitoring and management.
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A Study of Diesel-Hydrogen Fuel Mix in a Stationary Compression EngineHafez, HA Unknown Date (has links) (PDF)
The scarcity of fossil energy resources in conjunction with increasing demand has recently created record commodity price rises. Global warming and dimming are some of the harmful effects of increasing use of this resource. Furthermore, fossil fuel exhaust emissions, produced in internal combustion engines (ICE), generate significant health concerns. For decades, fears and numerous alarms have been raised regarding these problems. Many researchers believe that hydrogen would be an ideal alternative solution. Reduced fossil fuel consumption and lower thermal emanations (CO, CO2, HC and NO) are expected if hydrogen is used, as a principal or supplementary fuel, in standard ICE’s. However, hydrogen dual-fuel use has historically been associated with injection and/or detonation problems. Direct injection (DI) strategy, in spark and compression engines, is commonly used to overcome some, but not all, of these difficulties. This experimental research investigated detonation free, diesel-hydrogen fuel consumptions, and exhaust emissions using an indirect injection (IDI) strategy in a generic compression diesel engine.
A novel analogue Mechatronic Injection Unit (MICU) in conjunction with a multi point injection tactic (MPI) were devised to indirectly deliver low pressure hydrogen to a stationary Lister-Pitter diesel engine combustion chamber. The hydrogen injection system was created to be used as a generic dual-fuel kit. With off-the-shelf parts the MICU design was simple, robust, and purposeful in its function. The MICU component also formed an important element of a proposed innovative dual-fuel conversion kit. Nine hydrogen injection rates were tested. Diesel consumption savings were measured and the ‘effectiveness’ of hydrogen vitiated injection was computed.
The research outcomes demonstrated that with a conventional diesel mechanical governor and an assumed engine compression ratio of 15.5, detonation free combustion can be achieved with low pressure hydrogen vitiation and enrichment . However, an injection rate limit existed above which detonation occurred. The study also demonstrated that through low pressure hydrogen vitiation and enrichment, diesel consumption savings were achieved. The research confirmed that the experimental fuel mass savings were lower than their expected/theoretical counterparts. The research particularly established that vitiation and enrichment effectiveness was only realised at low rather than high loads indicating that hydrogen achieved more than diesel mass substitutions.
In this study a new confined area dual-fuel static emission testing procedure, coupled with an on-site use test cycle was proposed and termed the Dual-fuel fixed speed emission-testing guideline. Dry thermal emissions were measured, and both the cycle average and median dry- and wet-emissions were computed, substance/species comparisons were performed and conclusions were drawn. The shortcomings of the procedure however were also highlighted.
Finally, the research established that one action or measure, such as dual-fuel hydrogen vitiation and enrichment, can not address all the environment and health concerns. Contrary to the common belief, green house gases, nitrogen oxides, hydrocarbons and opacity substances do not coincidently all increase and/or decrease. Indeed, this experiment demonstrated that although the diesel-hydrogen nitrogen monoxide (NO) wet-emissions at all injection rates were partially lower than the diesel baseline, carbon oxides, hydrocarbon emissions, opacity (N) and absorption coefficients (k) were higher. In other words, a measure taken to limit the harm done to human health can increase the damage to the environment and vice versa.
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Multi-agent decision support system in avionics : improving maintenance and reliability predictions in an intelligent environmentHaider, Kamal January 2009 (has links)
Safety of the airborne platforms rests heavily on the way they are maintained. This maintenance includes repairs and testing, to reduce platform down time. Maintenance is performed using generic and specific test equipment within the existing maintenance management system (MMS). This thesis reports the work undertaken to improve maintainability and availability of avionics systems using an intelligent decision support system (IDSS). In order to understand the shortcomings of the existing system, the prevalent practices and methodologies are researched. This research thesis reports the development and implementation of an IDSS and the significant improvements made by this IDSS by integrating autonomous and independent information sources by employing a multi-agent system (MAS). Data mining techniques and intelligence agents (IA) are employed to create an expert system. The developed IDSS successfully demonstrates its ability to integrate and collate the available information and convert into valuable knowledge. Using this knowledge, the IDSS is able to generate interpreted alerts, warnings and recommendations thereby reasonably improving platform maintainability and availability. All facets of integrated logistics support (ILS) are considered to create a holistic picture. As the system ages, the IDSS also matures to assist managers and maintainers in making informed decisions about the platform, the unit under test (UUT) and even the environment that supports the platform.
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