A mixing budget for the Strait of Georgia was prepared summarizing mixing processes and effects upon the physical oceanography of the strait. A mixing budget was defined as an itemized estimate of mixing mechanisms and the total state of mixing in the strait. Mixing effects in the Strait of Georgia were estimated from hydrographic data and from monthly summaries of meteorological data for four months: February, May, August and November of 1968. Mixing was estimated qualitatively by depth-averaging temperature, salinity, density and oxygen concentrations for four representative layers, each 25 metres thick and by producing contour plots for each variable for the layers (two upper layers, an intermediate layer and a deep layer). Quantitative estimates of mixing were made by computing the potential energy density and the energy density needed for total mixing for the representative layers plus the potential energy density of total stratification (a fresh water layer over a layer with oceanic salinity). Changes in potential energy were due to mixing plus advection. Estimates of the energy available for mixing were made for the different mixing mechanisms acting upon the strait: wind mixing, buoyancy flux (convection) mixing, tidal mixing, mixing by internal waves and entrainment mixing. The Strait of Georgia has three different domains which are influenced by different mixing mechanisms: the southern passages, the upper layers of the northern strait and the deep waters. The southern passages (including the San Juan Archipelago and Haro and Rosario Straits) are the site of intensive tidal mixing which keeps the entire water column well mixed} convection and wind mixing are also important during the winter. The upper layers of the northern strait (north of Boundary Pas sage) are well mixed by the wind in the winter and by the wind and convection in the autumn. The uppermost brackish layer is highly stratified in the spring and summer from the effects of surface heating and fresh water runoff; intermediate layers are mixed by entrainment upwelling. The deep waters of the strait are influenced chiefly by advection processes: estuarine flow and seasonal intrusions of new water masses. In the winter, cold low-salinity water intrudes and displaces the warm water left from the previous summer while in the summer, warm saline water replaces the cold winter water. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

In this study, the bioconversion of manure and silage to biogas by an anaerobic digestion process in batch reactors was studied. Biogas is a valuable alternative energy source, mainly in rural areas. The main aim for the environment is to use biogas as a fuel instead of crude oil or natural gas. In this study, two different parameters were studied to observe the changes in methane productivity. The first three reactors were shaken once per week and the following three reactors were shaken 5 times per week. The results showed that mixing has no major effect on the methane production yield. In the second six reactors a mixture of 1% and 3% silage was added and the results were recorded. When the data from the reactors with just manure was compared to the reactors with 1% and 3% silage, it was seen that the silage increased the production rate and total gas produced. The process stabilization took a long time for digestion with the 3% silage possibly caused by release of too much fatty acids.

We find a set of conditions on a roof function to ensure topological mixing for suspension flows over a topological mixing base. In the measure theoretic case, such conditions have already been established for certain flows. Specifically, certain suspensions are topologically mixing if and only if the roof function is not cohomologous to a constant. We show that an analogous statement holds to establish topological mixing with the presence of dense periodic points. Much of the work required is to find properties specific to the equivalence class of functions cohomologous to a constant. In addition to these conditions, we show that the set of roof functions that induce a topologically mixing suspension is open and dense in the space of continuous roof functions.

Subgrouping is a mixing technique that most mix engineers use. Little research on perceptual evaluations of mixing techniques has been done and what little research that has, has been done on automatic mixing systems. When it comes to research on subgrouping in automatic mixing systems the results show a significant preference towards automatic mixes with subgroups over mixes without. This study aims to test the same notion that the use of subgroups improves listener preference but this time in mixes created by humans. A group of mix engineers created two mixes of one song, one with the use of subgroups and one without. These mixes were the stimuli of a listening experiment that was conducted to investigate listener preference of mixes with and without subgroups as well as what perceived qualities were most prevalent in preferred mixes and mixes with and without subgroups. The results showed that mixes without subgroups were preferred over mixes with subgroups, although, these results were not statistically significant. The results also showed that balance, frequency and clarity were the most prevalent sonic qualities that helped the listeners decide how to rank the mixes.

The United States has arbitrary weather criteria for a prescribed burn day to happen. This arbitrary criteria gives prescribed-burn managers a limited amount of days they can burn. To solve this, I established a 30-year climatology based on daily mixing height (m). I then calculated burn-day thresholds based on different mixing heights. I found seasonal and spatial patterns of the amount of days that are prescribed burns. Southeastern United States was my study area. A small decrease in threshold values will lead to large increases in prescribed burn days. Digital maps were created to show the spatial variability of prescribed burn days and the effects of lowering thresholds for prescribed burn days. This research will aid policy makers in lessening the criteria for burn days.

The 8-9 million year old volcanic complex of Oxnadalur is host to large-volume basalt flows, small and large volume rhyolite ash and lava flows, and a gabbroic intrusion. Both the plagioclase and pyroxene phenocrysts of the basalt are larger in size in the younger flows. The rhyolite ashes contain no primary crystals, but numerous basalt xenoliths and pumice fragments. The rhyolite lava flows are banded, with only the oldest containing phenocrysts of sanidine and plagioclase. One rhyolite flow is a mingled hybrid of two glasses, each containing plagioclase, pyroxene, and hornblende. Whole rock major and trace element analyses indicate a mixing trend among all of the units in the complex; yet abundant xenoliths in the ashes make this less data less dependable. In situ major and trace element analyses were performed via electron microprobe show two distinct populations in the variation diagrams, with the basalts and rhyolites separated by a compositional gap. Electron microprobe analyses also show that the plagioclase of the basalts and the gabbro are normally zoned with distinct calcic cores and sodic rims; this is also true for the mingled hybrid flow. Rare earth element analyses done via laser ablation inductively coupled plasma mass spectrometry, show that the phenocrysts are enriched in the light and depleted in the heavy rare earth elements. Rare earth element abundances in the glasses have a trend similar to that of ocean island basalt rather than that of mid ocean ridge basalt. Plagioclase geothermometry and amphibole geobarometry indicate that the magma chambers were replenished by new batches of melt and may have existed at a shallow level in the crust just prior to being erupted. Oxygen isotope ratios are depleted compared to those of typical mid ocean ridge basalts, typically indicating that the source melt was partially melted from a hydrothermally altered layer in the crust. As the δ18O values are whole rock, the depletion may be the result of any sub solidus interaction with low δ18O water. The data indicate that multiple shallow reservoirs evolved separately, with limited communication while being intruded by new magma throughout the lifespan of the complex.

archives@tulane.edu / The sharing of quantum resources between multiple parties allows for the creation of quantum networks. Traditional four-wave mixing creates twin correlated beams of light. More complex four-wave mixing schemes can create a multitude of correlated beams for use in quantum communication, helping pave the way toward future quantum networks. These correlations can be seen in the intensity-difference squeezing between output modes. In this dissertation, we examine a variety of multi-mode quantum systems. I begin in chapters 2 and 3 by using the noise figure, which compares the signal-to-noise ratios of output modes to input modes, to calculate intensity-difference squeezing and make predictions about phase-sensitivity. In chapter two, I analyze a dual-pump four-wave mixing system yielding three output modes for cases in which a single seed, two asymmetric seeds, and two symmetric seeds are used. In chapter 3, I perform similar calculations for three different cascaded four-wave mixing configurations. Various intensity-difference squeezing combinations are compared for two variations of two cascaded four-wave mixing cells and for three cascaded four-wave mixing cells. Chapter 4 describes a dual pump four-wave mixing scheme with four output modes created experimentally and chapter 5 shows that when only one input mode is seeded this process is phase-insensitive. Interestingly, I find that when only two of the input modes are seeded the system becomes phase-sensitive. Finally, in chapter 6, I describe the simulated and experimental results of using a deep neural network to improve the bit error rates in a classical free-space optical on-off keying scheme, that will eventually be expanded into the quantum regime. / 1 / Sara K Wyllie

No description available.

No description available.

No description available.