Well pressure transient analysis is widely used in reservoir management to obtain reservoir information needed for reservoir simulation, damage identification, well optimization and stimulation evaluation. The main objective of this project is to analyze, interpret and categorize the pressure transient responses obtained from 22 wells in a vuggy naturally fractured carbonate reservoir in an attempt to understand the heterogeneities of the porosity system. Different modeling techniques useful in simulating well behavior in vuggy naturally fractured reservoirs were developed and categorized. The research focused on pressure transient analysis using homogeneous, radial composite, single fracture, dual porosity and triple porosity reservoir models along with conventional boundary models which show boundary limits including single and double sealing boundary, closure and constant pressure boundary. A triple porosity model was developed, and it proved to be very effective for use in the analysis of the pressure responses obtained from this field. For some wells, the need for new models to characterize the pressure responses in more complex reservoirs was highlighted as conventional models failed.

Well pressure transient analysis is widely used in reservoir management to obtain reservoir information needed for reservoir simulation, damage identification, well optimization and stimulation evaluation. The main objective of this project is to analyze, interpret and categorize the pressure transient responses obtained from 22 wells in a vuggy naturally fractured carbonate reservoir in an attempt to understand the heterogeneities of the porosity system. Different modeling techniques useful in simulating well behavior in vuggy naturally fractured reservoirs were developed and categorized. The research focused on pressure transient analysis using homogeneous, radial composite, single fracture, dual porosity and triple porosity reservoir models along with conventional boundary models which show boundary limits including single and double sealing boundary, closure and constant pressure boundary. A triple porosity model was developed, and it proved to be very effective for use in the analysis of the pressure responses obtained from this field. For some wells, the need for new models to characterize the pressure responses in more complex reservoirs was highlighted as conventional models failed.

When mixing and mastering modern music, many engineers strive for making the end product to be perceived as loud as possible without sacrificing audio quality. Achieving this will often involve reducing the dynamic range of a track through peak limiting. By reducing the level of the loudest transients, the additional headroom can be used to raise the overall level of the track. This method of maximizing loudness through transient suppression has, arguably, made it more relevant to understand the human perception of transients. By further understanding the psychoacoustical factors that plays a role in how transient loudness is perceived, engineers could hopefully achieve greater audio quality while maximizing loudness, if desirable. This paper will focus on how the signal duration of a transient will affect its perceived loudness and potentially compensate for level changes within transients. The fact that sound signals of longer duration are perceived as louder than signals of shorter duration has been proven several times in prior research. This effect is tested again, in this research, by letting participants match the loudness of several short pink noise bursts of varying durations. The noise bursts are designed to mimic the envelope of a typical snare drum transient, which makes the stimuli differ from stimuli tested in prior experiments testing the same effect. Based on the result from this experiment, each transient is normalized to be perceived as equally loud. Then, a stationary component is added to every transient to make each stimuli mimic a full typical snare drum. In a second experiment, each stimuli is then compared against each other in an ABX test to see if listeners can perceive the differences.   The results from the first experiment showed that transients were perceived to be approximately 0.3 dB louder per 5 ms increase in duration. In the second experiment, listeners failed to hear the differences between stimuli when transient duration differed less than 5 ms. For differences in duration longer than this, listeners correctly identified the differences.

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The efficiency of photoconversion systems such as organic photovoltaic cells and photocatalytic water-splitting cells is largely governed by the interfacial charge transfer processes. Understanding the structure-function relationship, specifically at the molecular thin film/transparent conducting oxide interface will allow for engineering these interfaces to promote charge transfer and reduce the rate of charge recombination. Important factors that are hypothesized to influence charge transfer are morphology, chemical characteristics, electronic properties and molecular orientation. As molecules are bound to a transparent conducting oxide or incorporated into a thin film, the local solid-state molecular environment greatly influences the excited state properties of the molecule. Pathways for quenching, radiative and nonradiative decay drastically limit the excited state lifetimes. In order to investigate the photoinduced kinetics of thin films and at interfaces a instrument was developed coupling transient absorbance spectroscopy to attenuated total reflectance spectroscopy. The photoinduced kinetics of a thin film of bacteriorhodopsin was used to evaluate the instrument performance, and it was determined that 1% of a close-packed monolayer could be detected with this geometry. The properties of a molecular thin film/transparent conducting oxide were investigated by tethering zinc porphyrin to ITO. The electrochemical properties were influenced by the functional group of the binding moiety. To improve our understanding of how the solid state molecular environment affects excited states lifetimes, zinc porphyrins were incorporated into mono- and multilayer thin films and measured with transient ATR spectroscopy. Finally, multilayer films related to photocatalytic water-splitting were investigated with the incorporation of inorganic nanosheets. The nanosheets helped to create a stratified assembly for multilayer films, spatially segregating electron donor (palladium porphyrin) and electron acceptor (poly(viologen)) molecules. The role of the nanosheets in the electron transfer between the donor and acceptor was studied by monitoring the triplet state lifetimes of a palladium porphyrin with transient ATR spectroscopy.

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I describe an experimental apparatus used to perform deformation experiments relevant to volcanology. The apparatus supports low-load, high-temperature deformation experiments under dry and wet conditions on natural and synthetic samples. The experiments recover the transient rheology of complex (melt ± porosity ± solids) volcanic materials during uniaxial deformation. The key component to this apparatus is a steel cell designed for high-temperature deformation experiments under controlled water pressure. Experiments are run under constant displacement rates or constant loads; the range of accessible experimental conditions include: 25 - 1100 °C, load stresses 0 to 150 MPa, strain rates 10⁻⁶ to 10⁻² s⁻¹, and fluid pressures 0-150 MPa. I present a suite of high-temperature, uniaxial deformation experiments performed on 25 by 50 mm unjacketed cores of porous Φ∼0.8) sintered rhyolitic ash. The experiments were performed at, both, atmospheric (dry) and elevated water pressure conditions (wet). Dry experiments were conducted mainly at 900 °C, but also included a suite of lower temperature experiments at 850, 800 and 750 °C. Wet experiments were performed at ∼650 °C under water pressures of 1, 2.5, 3, and 5 MPa, and at a fixed PH2O of ∼2.5 MPa for temperatures of ∼385, 450, and 550 °C. During deformation, strain is manifest by shortening of the cores, reduction of porosity, flattening of ash particles, and radial bulging of the cores. The continuous reduction of porosity leads to a dynamic transient strain-dependent rheology and requires strain to be partitioned between a volume (porosity loss) and a shear (radial bulging) component. The effect of increasing porosity is to expand the window for viscous deformation for dry melts by delaying the onset of brittle deformation by ∼50 °C (875 °C to 825 °C). The effect is more pronounced in hydrous melts (∼0.67 — 0.78 wt. % H₂0) where the viscous to brittle transition is depressed by ∼140 to 150 °C. Increasing water pressure also delays the onset of strain hardening due to compaction-driven porosity reduction. These rheological data are pertinent to volcanic processes where high-temperature porous magmas I liquids are encountered (e.g., magma flow in conduits, welding of pyroclastic materials).

I describe an experimental apparatus used to perform deformation experiments relevant to volcanology. The apparatus supports low-load, high-temperature deformation experiments under dry and wet conditions on natural and synthetic samples. The experiments recover the transient rheology of complex (melt ± porosity ± solids) volcanic materials during uniaxial deformation. The key component to this apparatus is a steel cell designed for high-temperature deformation experiments under controlled water pressure. Experiments are run under constant displacement rates or constant loads; the range of accessible experimental conditions include: 25 - 1100 °C, load stresses 0 to 150 MPa, strain rates 10⁻⁶ to 10⁻² s⁻¹, and fluid pressures 0-150 MPa. I present a suite of high-temperature, uniaxial deformation experiments performed on 25 by 50 mm unjacketed cores of porous Φ∼0.8) sintered rhyolitic ash. The experiments were performed at, both, atmospheric (dry) and elevated water pressure conditions (wet). Dry experiments were conducted mainly at 900 °C, but also included a suite of lower temperature experiments at 850, 800 and 750 °C. Wet experiments were performed at ∼650 °C under water pressures of 1, 2.5, 3, and 5 MPa, and at a fixed PH2O of ∼2.5 MPa for temperatures of ∼385, 450, and 550 °C. During deformation, strain is manifest by shortening of the cores, reduction of porosity, flattening of ash particles, and radial bulging of the cores. The continuous reduction of porosity leads to a dynamic transient strain-dependent rheology and requires strain to be partitioned between a volume (porosity loss) and a shear (radial bulging) component. The effect of increasing porosity is to expand the window for viscous deformation for dry melts by delaying the onset of brittle deformation by ∼50 °C (875 °C to 825 °C). The effect is more pronounced in hydrous melts (∼0.67 — 0.78 wt. % H₂0) where the viscous to brittle transition is depressed by ∼140 to 150 °C. Increasing water pressure also delays the onset of strain hardening due to compaction-driven porosity reduction. These rheological data are pertinent to volcanic processes where high-temperature porous magmas I liquids are encountered (e.g., magma flow in conduits, welding of pyroclastic materials).