Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"charge motion"”.
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Probing charge motion in next-generation semiconductors with scanned probe microscopy
… researchers to explore spatial variations in charge generation and transport in solar-cell films prepared on a conductive substrate with a best-case resolution of 2 nanometers. In this thesis, we introduce new scanned probe measurements to measure light- and voltage-induced changes to …
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Effects of charge motion control during cold start of SI engines
… to investigate the effects of various intake charge motion control approaches on the cold start-up process of a port fuel injected SI engine. Engine experiments were performed to assess the effectiveness of enhanced charge motion on mixture preparation, combustion, and hydrocarbon (HC) …
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The effect of liner design upon charge motion in a rotary mill
… a liner material cost of about R30 million. The charge motion in mills has been studied both theoretically and experimentally since the beginning of the century. However, a lot of the work has been purely empirical, and some of it illconceived, resulting in there still being a poor understanding …
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A study of charge motion in rotary mills, with particular reference to the grinding action
… understanding of the action of the grinding charge in a mill, and to then correlate this with the metallurgical performance of different mill-liners. To achieve these overall objectives it was first necessary to develop suitable experimental techniques, and the development of these techniques …
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Spray characterization of flex-fuel gasoline di injectors and spray interaction with charge motion in a variable valve actuation engine
… of GDI sprays and behavior of in-cylinder charge motion in a GDI engine which is equipped with variable valve actuation. High speed spray visualization in a spray chamber was conducted for a study of spray development. By Schlieren visualization technique, the effect of different conditions …
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The study of the influence of the lifter height on the charge motion, velocity profile and power draw of a laboratory tumbling mill using DEM simulations
… lifter height has been shown to influence the charge motion and power draw of the mill. Most of the predictive power models used in industry do not consider lifter heights as a variable. In comminution, Positron Emission Particle Tracking (PEPT) is used to track the charge motion of particles …
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Effect of directed port air flow on liquid fuel transport in a port fuel injected spark ignition engine
… designs. The effect of a turbulence plate, or charge motion control valve, on the port liquid fuel mass is examined. A purging process was used to examine the effect of a charge motion control plate on the port fuel film mass. It was found that the charge motion plate can provide substantial …
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Multicomponent Liquid and Vapor Fuel Distribution Measurements in the Cylinder of a Port -Injected, Spark -Ignition Engine
The engine results show that large-scale charge motion induced during intake is paramount to good mixing during intake and compression. High intake port velocity is important for initial droplet atomization, but does not guarantee complete mixing. Liquid wall impingement can lead to significant …
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Combustion optimization in a hydrogen-enhanced lean burn SI engine
… focused on three key areas: the ignition system, charge motion in the inlet ports, and mixture preparation. The ignition system tests compared a standard inductive coil scheme against high-energy discharge systems. Charge motion experiments focused on the impact of turbulence patterns generated by …
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Research on late-robust combustion
… an experimental study was carried out in which charge motion or laminar flame speed was varied. Two sets of tests were done. The first consisted of using an air jet mounted in the intake port to generate charge motion at a spark-timing sweep from 20⁰ BTC to 200 ATC. Two jet orientations were …
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Effects of engine operating conditions on catalyst light-off and combustion variability
… was investigated, with a typical downsized, turbocharged four-cylinder GDI engine used to incorporate physical effects from engine operation. Based on these experimental results a converter light-off model was developed that accurately simulates converter light-off with back pressure. Fuel …
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Multihole injectors for direct-injection gasoline engines
… The effects of injection timing, in-cylinder charge motion and injector tip layout have been quantified. The flexibility in nozzle design of the multi-hole injectors has proven to be a powerful tool in terms of matching overall spray cone angle and number of holes to specific engine …
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Using discrete element modelling (DEM) and breakage experiments to model the comminution action in a tumbling mill
… well suited for simulating tumbling mills whose charge is principally individual particles (steel balls, rocks and fines). The use of DEM to simulate tumbling mills has proliferated since the early 1990s and been successfully employed to predict important milling parameters such as charge motion, …
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Measurement of particle interaction properties for the incorporation into Discrete Element Methods
… technique for predicting the dynamics of charge motion with in a mill. Particle interactions in DEM are calculated by contact force and force displacement laws at each particle contact. These contact events are characterized by parameters that are often fitted or estimated due to the lack …
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Hydrocarbon emissions in a homogeneous direct-injection spark engine : gasoline and gasohol
… driving. The effects of coolant temperature, the charge motion control valve, spark timing and rail pressure were tested through holding all other variables constant and sweeping through different injection timing to observe the effect on emissions and power output. A new fuel system was designed …
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Simulations And Experiments Of Fuel Injection, Mixing And Combustion In Di Gasoline Engines
… Finally, the interactions of sprays with the charge motion are investigated in an optical accessible engine using CFD simulation and high-speed imaging of sprays inside engines. </p> <p> The numerical results DI injector nozzle show that the complicated unsteady flow features dominate the …
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Modeling and characterization of ionic polymer transducers for sensing and actuation
… models are developed to characterize the charge motion that develops within an ionomer when subject to either mechanical or electrical loading. These models characterize the internal potential and charge density responses of the membrane, as well as the expected surface current that would …
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Using positron emission particle tracking (PEPT) to investigate the motion of granular media in a laboratory-scale tumbling mill
… mill analysis includes the identification of charge features and regions, and the isolation of charge in each region so-defined for further analysis. These features, particularly the shape of the bulk free and equilibrium surfaces, the angular position of the centre of circulation (CoC) of the …
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High Performance Disulfonated Poly(arylene Sulfone) Co- and Terpolymers For Proton Exchange Membranes For Fuel Cell And Transducer Applications: Synthesis, Characterization And Fabrication Of Ion Conducting Membranes
… a strong correlation between the capacitance and charge motion.
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Möglichkeiten und Grenzen der Teillaststeuerung von Ottomotoren mit vollvariablem Ventilhub
Im Rahmen dieser Arbeit werden die Potenziale zur Steigerung des Gesamtwirkungsgrads von stöchiometrisch homogen betriebenen Ottomotoren in der Teillast untersucht. Im Gegensatz zur konventionellen Laststeuerung über die Drosselklappe bezeichnet die betrachtete, drosselfreie Laststeuerung die …