In this dissertation, the electrical characteristics of the interface between the metal cathode and organic layer in OLEDs are detailed investigated. Currently, surveying on the literature, it is limited in understanding the interfacial characteristics and the injection process of electron at interface, therefore the carrier injection phenomena investigated here is still based on the traditionally inorganic semiconductor physics. As a thin LiF layer inserted between the Al and Alq3 layers, the performance of OLED shown a great deal of improvement, such as lowering the driving voltage and increasing the luminescence efficiency. At first, we study how a very thin LiF layer affecting the performance of OLED device, and the feasible mechanisms attributed to this improvements. Then, the further discussion should be focused on the injection model built for the charge at metal/organic interfaces. Finally, the relationship that the injection model related to the variety of LiF layer thickness could be investigated. From the experimental data, the Al/LiF/Alq3 devices with the LiF thickness of 0.5nm have shown the best performance, and the device performance decay as the thickness of LiF layer increased over 0.5nm. In this study, it assumes that the LiF layer just forms an ¡§integrated¡¨ thin insulating film and lowing the charge injection as the layer thickness over 0.5nm, and it also assume that in model derived process is independent on the metal work function. Since the molecular structure of organic materials is quite difference from the valence band structure in inorganic semiconductor materials, it could be assumed no band bending like that the p-n junction at the interface of inorganic semiconductor under thermal equilibrium. After theoretical approach, we get the reasonable results by comparing with the literatures reported recently. The conclusion of this study reveals that the charge injection is independent on the metal work function, but is determined by the interface structure characteristic of interface structure at metal/organic interfaces. Furthermore, in the Al/LiF/Alq3 structure, the chemical reaction is saturated at the interface as the LiF layer forms a ¡§integrated¡¨ thin insulating film. Therefore, the device performance decay is the effect due to the insulating LiF layer when the thickness of LiF layer is over 0.5nm.

In this work, numerical simulations of flow separation control are performed. The sep-aration control technique studied is called 'synthetic jet actuation'. The developed code employs a cell centered finite volume scheme which handles viscous, steady and unsteady compressible turbulent flows. The pulsating zero mass jet flow is simulated by imposing a harmonically varying transpiration boundary condition on the airfoil's surface. Turbulence is modeled with the algebraic model of Baldwin and Lomax. The application of synthetic jet actuators is based in their ability to energize the boundary layer, thereby providing signifcant increase in the lift coefficient. This has been corroborated experimentally and it is corroborated numerically in this research. The performed numerical simulation investigates the flow over a NACA0015 air-foil. For this flow Re = 9??105 and the reduced frequency and momentum coefficient are F+ = 1:1 and C?? = 0:04 respectively. The oscillatory injection takes place at 12.27% chord from the leading edge. A maximum increase in the mean lift coefficient of 93% is predicted by the code. A discrepancy of approximately 10% is observed with corresponding experimental data from the literature. The general trend is, how-ever, well captured. The discrepancy is attributed to the modeling of the injection boundary condition and to the turbulence model.A sensitivity analysis of the lift coefficient to different values of the oscillation parameters is performed. It is concluded that tangential injection, F + ?? O(1) and the utilized grid resolution around the site of injection are optimal. Streamline fields ob-tained for different angles of injection are analyzed. Flow separation and attachment as functions of the injection angle and of the velocity of injection can be observed. It is finally concluded that a reliable numerical tool has been developed which can be utilized as a support tool in the optimization of the synthetic jet operation and in the modeling of its operation.

The Raman Injection Laser is a new type of laser which is based on triply resonant stimulated Raman scattering between quantum confined states within the active region of a Quantum Cascade Laser that serves as an internal optical pump. The Raman Injection Laser is driven electrically and no external laser pump is required. Triple resonance leads to an enhancement of orders of magnitude in the Raman gain, high conversion efficiency and low threshold. We studied this new type of laser and conclude some basic equations. With reasonable experimental parameters, we calculated the laser gain, losses and the output power of the Raman Injection Laser by using Mathematica and FEMLab. Finally we compared the theoretical and experimental results.

Fracture-injection/falloff sequences are routinely used as pre-frac well tests to estimate reservoir pressure and transmissibility, but the current interpretation methods are limited to analyzing specific and very small portions of the pressure falloff data. To remove the current limitations, new analytical fractureinjection/ falloff models are developed that account for fracture propagation, fracture closure, and after fracture closure diffusion. A fracture-injection/falloff differs from a conventional injection/falloff sequence in that pressure during the injection is sufficient to initiate and propagate a hydraulic fracture. By considering fracture propagation as time-dependent storage, three new models are presented for a fractureinjection/ falloff sequence in a well in an infinite slab reservoir with a single vertical fracture created during the injection and with variable fracture and wellbore storage as follows: • Equivalent propagating-fracture and before-fracture-closure storage with constant after-fractureclosure storage. • Time-dependent propagating-fracture storage, constant before-closure storage, and constant afterclosure storage. • Time-dependent propagating-fracture storage, constant before-closure storage with linear flow from the fracture, and constant wellbore storage and skin with after-closure radial flow. When a fracture-injection can be considered as occurring instantaneously, limiting-case solutions of the new fracture-injection/falloff models suggest the observed pressure difference can be integrated to generate an equivalent pressure difference if the rate were constant. Consequently, a fractureinjection/ falloff sequence can be analyzed with constant-rate, variable-storage type curves. The new fracture-injection/falloff theory is also extended to allow for a fracture-injection in a reservoir containing an existing conductive hydraulic fracture. The new multiple-fracture fracture-injection/falloff model forms the basis of a new refracture-candidate diagnostic test that uses characteristic variable-storage behavior to qualitatively diagnose a pre-existing fracture retaining residual width and to determine if a preexisting fracture is damaged. A quantitative analysis methodology is also proposed that uses a new pressure-transient solution for a well in an infinite-slab reservoir producing through multiple arbitrarilyoriented finite- or infinite-conductivity fractures.

Water alternating gas (WAG) injection is a proven technique to enhance oil recovery. It has been successfully implemented in the field since 1957 with recovery increase in the range of 5-10% of oil-initially-in-place (OIIP). In 2004, Herbert L. Stone presented a simultaneous water and gas injection technique. Gas is injected near the bottom of the reservoir and water is injected directly on top at high rates to prevent upward channeling of the gas. Stone's mathematical model indicated the new technique can increase vertical sweep efficiency by 3-4 folds over WAG. In this study, a commercial reservoir simulator was used to predict the performance of Stone's technique and compare it to WAG and other EOR injection strategies. Two sets of relative permeability data were considered. Multiple combinations of total injection rates (water plus gas) and water/gas ratios as well as injection schedules were investigated to find the optimum design parameters for an 80 acre 5-spot pattern unit. Results show that injecting water above gas may result in better oil recovery than WAG injection though not as indicated by Stone. Increase in oil recovery with SSWAG injection is a function of the gas critical saturation. The more gas is trapped in the formation, the higher oil recovery is obtained. This is probably due to the fact that areal sweep efficiency is a more dominant factor in a 5-spot pattern. Periodic shut-off of the water injector has little effect on oil recovery. Water/gas injection ratio optimization may result in a slight increase in oil recovery. SSWAG injection results in a steady injection pressure and less fluctuation in gas production rate compared to WAG injection.

The recent pollution norms have brought a strong emphasis on the reduction of diesel engine emissions. Low temperature combustion technology such as premixed compression ignition (PCI) has the capability to significantly and simultaneously reduce nitric oxides (NOx) and particulate matter (PM), thus meeting these specific pollution norms. There has been, however, observed loss in fuel conversion efficiency in some cases. This study analyzes how energy transfer and brake fuel conversion efficiency alter with (or are affected by) injection timings and exhaust gas recirculation (EGR) rate. The study is conducted for PCI combustion for four injection timings of 9°, 12°, 15° and 18° before top dead center (BTDC) and for four exhaust gas recirculation (EGR) rates of 39%, 40%, 41% and 42%. The data is collected from the experimental apparatus located in General Motors Collaborative Research Laboratory at the University of Michigan. The heat release is calculated to obtain various in-cylinder energy transfers. The brake fuel conversion efficiency decreases with an increase in EGR. The decrease in the brake fuel conversion efficiency is due to the decrease in work output. This decrease is due to an increase in the pumping work and an increase in friction and decrease in gross indicated work. The decrease in the combustion efficiency is because of the increased formation of unburnt products due to increased ignition delay caused by the application of EGR and decreasing air-fuel (A/F) ratio. A definite trend is not obtained for the contribution of heat transfer to the total energy distribution. However the total heat transfer decreases with retardation of injection timing because of decreasing combustion temperature. As the injection timing is retarded, the brake fuel conversion efficiency is found to decrease. This decrease is because of a decrease in net work output. This is because the time available for utilization of the energy released is less because of late combustion. The total heat transfer decreases with retardation of injection timing because of decreasing combustion temperature. The contribution of heat transfer to the total energy distribution decreases with increase in EGR.

Replacing steel and wood with plastic is the developing trend in the modern industry. In many shaping processing methods¡M the injection molding technology is widely used in plastic industry for its good adaptability¡M high producing efficiency and easy-achieve to automation. Injection molding is a very complicated physical process¡M the molding parameters (including temperature¡M pressure¡M time¡M speed and position etc) and environment condition will directly affect the flowing condition of melting plastic and final quality of products¡M so to obtain the best molding parameters is the key to improve the quality of the plastic products. The traditional method of adjusting parameters is try and error¡M which wastes time and materials. And it¡¦s also hard to accumulate and transmit experience¡M so we urgently need to find a new method. By going through a long time of experiment and exploring¡M we found that the DOE (Design of Experiment)¡M which is one of the most important tools of 6 sigma¡M can be applied to improving the molding processing¡M and it will bring us the innovation of injection molding technology. DOE is one of the mathematic methods¡Mwhich bases on Probability theory¡M Statistics and Linear algebra¡M through rationally arrange experiment and correctly analyze the results of experiment¡M to obtain the best parameters. In the processing of exploring¡M we have obtained first-step success in shortening cycles¡M reducing weight of product and improving qualities. For the sake of extending and developing the methods of DOE applied to molding technology in the company and transmitting experience of experts¡M we are going to conclude many DOE cases as a rule¡M establish a database¡M develop an injection molding expert system¡M which will be the effective way to bring cost down¡M improve efficiency and establish a core-competition capability of injection molding technology.

Thesis (M.S.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 116).

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 129-140).

Reproduction de : Thèse de doctorat : Electronique : Toulouse, INPT : 1999. / Titre provenant de l'écran-titre. Bibliogr. 78 réf.