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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
481

Sinners in the City of Saints: Flappers in Salt Lake City

Romero, Bree Ann 01 May 2014 (has links)
Social commentators typically recognized the flapper as a break from tradition in the nineteen twenties. Scholars have since tended to do the same. Those characterizations, however, generally ignore the flappers outside of the Caucasian, urban, middle-class set. This thesis aims to contribute to a more comprehensive analysis of the flapper through a study of young women in Salt Lake City, Utah.
482

Consumer Attitudes Affecting the Use of Fluid Milk Products in Metropolitan Salt Lake City

Monson, Wayne N. 01 May 1968 (has links)
A survey of 360 respondents in metropolitan Salt Lake City was made to determine their attitudes about fluid milk products and the affect of these attitudes on consumption levels. The fluid milk products studied were regular whole milk, two percent milk, skim milk, and nonfat dry (powdered) milk. The respondents had the most positive attitudes about regular whole milk. Their attitudes about the other three products were highest for those which most nearly resembled regular whole milk . The consumption levels of the four products followed the same pattern. The respondents' attitudes about four attitude parameters affected their consumption levels. Those respondents with positive attitudes about these parameters consumed more than those with neutral or negative attitudes. The four parameters were taste-refreshment, nutritionvitality, appropriateness, and convenience.
483

Effect of Silicon on Wheat Growth and Development in Drought and Salinity Stress

Tibbitts, Spencer A. 01 May 2018 (has links)
Silicon is a major component of most soils, and is found in significant concentration in plant tissue. Plants vary widely in the amount of silicon they take up, with some plants excluding it, and others using transporters to move the silicon from the soil into their roots. Early plant physiology studies were unable to determine conclusively whether silicon was essential to plant growth, but for some plants, most notably rice, it has proved to be important enough to justify fertilizing silicon deficient fields. Researchers at the USU Crop Physiology Lab tested the effect of silicon on wheat growth and seed yield components. One study was grown in buckets of peat moss, with half the buckets being stressed with low water. The other study was grown in hydroponic tubs, with half the tubs being stressed with high levels of salt. The results from these studies showed that silicon does increase wheat seed yield and vegetative mass. Wheat with low levels of silicon exhibited twisting of the awns and decreased roughness of leaf surfaces. Silicon also improved water efficiency of drought stressed plants, and affected the concentration of many micro- and macro-nutrients in leaf tissue.
484

The Effectiveness of Leaching and Soil Amendments in Improving a Salt-Affected Soil of the Hooper Area of Utah

Haycock, Edwin Baugh 01 May 1963 (has links)
In the relatively low lying delta area west of Ogden, Utah several thousand acres of potentially productive lands have been seriously affected by the accumulation of soluble salts and the associated condition of excessive exchangeable sodium. As a part of the Weber Basin Project, much of this large area of undeveloped or only partially developed land is proposed for irrigation. Successful irrigation of these salt-affected lands, however, is dependent upon their reclamation and improvement.
485

Development of a Water Quality Model Applicable to Great Salt Lake, Utah

Jones, Craig T. 01 May 1976 (has links)
The development of a model capable of predicting the long term (seasonal) distribution of water quality constituents within Great Salt Lake was undertaken as a portion of the ongoing Great Salt Lake project at Utah State University. The overall goal of the project is the development of a modeling framework to assist the relevant decision making bodies in the comprehensive management of the Great Salt Lake system. Phase I of the project provided the overall structural framework for management of the Great Salt Lake system, identified data needs, and established priorities for the development of submodels for incorporation into the overall framework. Phase II of the project involves the process of developing submodels, and Phase III will be concerned with application of the framework of models to specific management problems. This study provides, as part of the second phase of the Great Salt Lake project, a model capable of predicting the long term distribution of quality constituents within the lake. This capability is a necessary component of the modeling framework since it will allow the investigation of the effects which alternative water quality management plans will have on the distribution of water quality constituents within the lake. The water quality model of the lake is based on the application of the advection-diffusion equation to the three-dimensional transport of a quality constituent. The modeling technique is formulated by discretizing the system as a network of nodes interconnected by channels in both the horizontal and vertical directions. This representation of the system allowed the horizontal transport to be treated mathematically as one-dimensional. The resulting modeling technique is applicable to any lake, estuary, or bay in which the concentration gradients must be described in all three coordinate directions. In applying the model to Great Salt Lake a two-layered vertical network was employed due t o the physical characteristics of the system. The model was further simplified by describing vertical transport by diffusion alone. Using observed total dissolved solids concentrations, a method was developed during the study for establishing the vertical diffusion coefficient as a function of depth. A unique feature of this water quality modeling technique is that it allows the seasonal distribution of a quality constituent to be studied without the necessity of developing a hydrodynamic model of the system . The advective transport is designed to be input to the model based on observed long term circulation patterns . In the case of Great Salt Lake, circulation patterns are not yet well known. However, approximate patterns h a ,, e been established from some observations to date , and those were used to provide preliminary tests of the validity and response characteristics of the model. These tests have demonstrated that the model will be a practical and useful tool for monitoring the distribution of quality constituents within the lake.
486

Nitrogen Cycling in a Microcosm Simulation of the Northern Arm of the Great Salt Lake

Stube, John C. 01 May 1976 (has links)
Nitrogen cycling was studied in the hypersaline northern arm of the Great Salt Lake (332,480 mg/l total dissolved solids) using a sediment-water microcosm simulation of that system. The study demonstrated that nitrate, ammonia, and urea were not stimulating to the halophilic bacteria in the microcosm. The bacteria were simulated only indirectly simulated bacterial growth. In addition, no nitrification could be demonstrated during the study. Weekly analyses of water samples from the north arm of the lake itself showed that nitrate and nitrite were absent, leaving ammonia as the only significant form of inorganic nitrogen in the northern lake basin. Other work on lake samples has indicated that no nitrogen fixation occurs in this system. Thus, the absence of nitrogen fixation, nitrification, and denitrification (because of the absence of nitrate) make it apparent that the production and the utilization of ammonia are the only two significant nitrogen cycling pathways operating in this system. The equilibrium established between the conversion of ammonia into organic nitrogen and the production of ammonia from mineralization of this organic matter is then responsible for the conditions which are found in the northern arm of the Great Salt Lake.
487

Computer Simulation of Urban Runoff Characteristics Within Salt Lake County

Parnell, Robert Newman 01 May 1971 (has links)
A hybrid computer program is developed to simulate the outflow hydrographs of two urban watersheds located within Salt Lake County, Utah. The gaged outflow of the watersheds provided a checkpoint for comparing the observed and the simulated final outflow hydrographs. The outflow hydrographs for each subzone of the two watersheds were obtained by abstracting interception, infiltration and depression storage from each subzone hyetograph. The outflow of the subzones were routed to the Jordan River, the final outflow point of the two watersheds. The final hydrographs of the watersheds were combined and compared with the gaged flow. The uniquenesses of this systems model are the flexibility in varying hyetographs, variable loss rates, combination of subzone hydrographs, and the combination of watershed hydrographs. Subzone hydrographs can also be plotted for visual inspection as well as obtaining numerical values. With a variety of input and output data, designers and planners can visually perceive urban runoff characteristics. The systems model should be a tool used by those interested in urban runoff characteristics.
488

The distribution pattern of algal flora in saline lakes in Kambalda and Esperance, Western Australia

Handley, Michelle Anne January 2003 (has links)
The study has attempted to characterise the physicochemical limnology and distribution of algal flora of two salt lake systems in Western Australia, one from the coastal Esperance region and the other from the inland Kambalda region. Climatic conditions, water regimes and physicochemistry were found to differ markedly between the two lake systems and a total of 171 algal taxa, representing five divisions, were recorded. Of these, 82 were members of Bacillariophyta, 48 of Cyanophyta, 33 of Chlorophyta, two of Euglenophyta and six of Dinophyta. The physical limnology of salt lakes in the Esperance region was seasonally variable, defined by climatic conditions. As such, the lakes investigated in the region exhibited a stable cycle of filling during winter and spring, and drying out in summer. Four of the lakes in the region could be classified as near-permanent, and one as seasonal on the basis of predictability and duration of filling. Seasonal fluctuations in water depth resulted in fluctuations in salinity levels. Salinity levels ranged from subsaline to hypersaline, and all the lakes in the region were alkaline. In addition, the lakes were well mixed in terms of oxygen and temperature, and were impacted by eutrophication from their catchments. They were either mesotrophic or eutrophic with respect to both nitrogen and phosphorus. In geological terms, lakes in the Esperance region were separated only recently from the ocean, and two lakes retain a connection with marine waters, one through a creek during years of high rainfall and one through hydrological interactions with groundwater of marine origin. In general, the algal communities of lakes in the Esperance region were similar to those of other Australian coastal salt lakes. / Diatoms and cyanobacteria were dominant in all lakes except the most eutrophic, Lake Warden, in which benthic green algae were most abundant. All algal species recorded were known for their wide geographic distribution and their distribution in Australian coastal waters. Characteristically coastal diatom species included Achnanthes brevipes, Achnanthes coarctata, Achnanthes lanceolata var. dubia, Achnanthidium cruciculum, Campylodiscus clypeus, Cyclotella atomus, Cyclotella meneghiniana, Cyclotella striata, Mastogloia elliptica, Mastoglia pumila, Nitzschia punctata and Thalassiosira weissflogii. The inland salt lakes of the Kambalda region form part of an extensive palaeodrainage system, and were much less predictable in terms water regime than lakes in Esperance. Water depth was determined by seasonal variability in rainfall and evaporation, and by summer cyclonic rainfall events that were unreliable from year to year. In addition, rainfall varied spatially within the region. As such, most lakes were classified as intermittent. Two lakes in the region were not classified on the basis of water regime as they were too highly impacted by mining activities including water diversion and impoundment, water extraction and discharge of groundwater. Salinity varied in accordance with drying and filling cycles in the lakes except the most hypersaline as the volume of water received during rainfall events was insufficient to dilute the extensive surface salt crusts they each supported when dry. Salinities recorded in the region ranged from subsaline to hypersaline, and ionic compositions exhibited the same spectrum as seawater. / Calcium levels were significantly higher than in lakes from the Esperance region due to weathering of calcium rich sediments, and pH ranged from weakly acidic in the most hypersaline lakes to alkaline in the least saline lakes. All were well mixed in terms of oxygen and temperature. Kambalda salt lakes support distinctive algal communities dominated by diatoms and cyanobacteria that are adapted to intermittent water regimes, extended periods of desiccation and variable salinity. Not surprisingly then, none of the algal taxa recorded from the region were regionally restricted, all noted previously in the literature to have wide geographic distributions, and to be tolerant of a range of physicochemical conditions. Canonical correspondence analysis showed that, of the physicochemical parameters that were investigated in this study, both salinity and pH interacted in determining algal community structure. Both of these attributes were correlated with water depth, which varied according to climatic conditions in a seasonal drying and filling cycle. The general relationship between species richness and pH and salinity, and species diversity and pH and salinity was simple and linear; with increasing pH and salinity, species diversity and species richness decreased. What was less simple, and non-linear, was the nature of the relationship between species richness and diversity and salinity within more narrowly defined ranges of salinity. As salinity increased from <1ppt to 30ppt there was a dramatic reduction in species richness and diversity, then, as salinity increased from 30ppt to 100ppt the rate of decrease slowed. Between 100ppt and 250ppt there was almost no relationship between salinity and species richness and species diversity, but after 250ppt both species diversity and species richness declined markedly.
489

Temperate urban mangrove forests : their ecological linkages with adjacent habitats

Yerman, Michelle N., University of Western Sydney, College of Science, Technology and Environment, School of Natural Sciences January 2003 (has links)
Estuarine habitats along the temperate south-eastern shores of Australia are generally made up of salt marsh, mangrove forests and seagrass beds. In urban areas these habitats have been progressively fragmented as a result of population increase and industrial expansion. Salt marshes in particular have been vulnerable to urban expansion and reclamation because of their close proximity to densely populated areas, while mangrove forests have been less often reclaimed because of frequent tidal inundation. The effect of reclamation of salt marshes on the biotic assemblages and functioning of mangrove forests with an adjacent salt marsh, park or bund wall was examined at nine separate locations on the Parramatta River, Sydney NSW. A mensurative approach was used to describe the patterns of distribution and abundance of macro fauna at several temporal and spatial scales. The implications for management are that salt marshes are an integral part of estuaries, and smaller patches of salt marsh are just as important as larger patches in maintaining the diversity of faunal assemblages and ecosystem functioning in mangrove forests in urban areas / Master of Science (Hons)
490

Convection, turbulent mixing and salt fingers

Wells, Mathew Graeme, mathew@inferno.phys.tue.nl January 2001 (has links)
In this thesis I address several topics concerning the interaction of convection and density stratification in oceans and lakes. I present experimental and theoretical investigations of the interaction between a localized buoyancy source and a heat flux through a horizontal boundary, and of the interactions between salt fingers and intermittent turbulence or shear. ¶ An extensive series of laboratory experiments were used to quantify the stratification and circulation that result from the combined presence of a localized buoyancy source and a heat flux through a horizontal boundary. Previous studies found that convection in the form of a turbulent buoyant plume tends to produce a stable density stratification, whereas the distributed flux from a horizontal boundary tends to force vigorous overturning and to produce well-mixed layers. A new result of this thesis is that a steady density profile, consisting of a mixed layer and a stratified layer, can exist when the plume buoyancy flux is greater than the distributed flux. When the two fluxes originate from the same boundary, the steady state involves a balance between the rate at which the mixed layer deepens due to entrainment on the one hand and vertical advection of the stratified water far from the plume (due to the volume flux acquired by entrainment) on the other hand. There is a monotonic relationship between the normalized mixed layer depth and flux ratio R (boundary flux/plume flux) for 0 < R > 1, and the whole tank overturns for R > 1. The stable density gradient in the stratified region is primarily due to the buoyancy from the plume and for R > 0 there is a small increase in the gradient due to entrainment of buoyancy from the mixed layer. For the case of fluxes from a plume located at one boundary and a uniform heat flux from the opposite boundary the shape of the density profile is that given by Baines & Turner (1969), with the gradient reduced by a factor (1 + R) due to the heating. Thus, when R < - 1 there is no stratified region and the whole water column overturns. When 0 > R > - 1, the constant depth of the convecting layer is determined by the Monin-Obukhov scale in the outflow from the plume. ¶ One application of these laboratory experiments is to surface cooling in lakes and reservoirs that have shallow sidearms. During prolonged periods of atmospheric cooling, gravity currents can form in these sidearms and as the currents descend into the deeper waters they are analogous to isolated plumes. This can result in stratification at the base of a lake and an upwelling of cold water. Away from the shallow regions, surface cooling leads to a mixed surface layer. The depth of this layer will be steady when the rate of upwelling balances the rate at which the mixed layer deepens by turbulent entrainment. A series of laboratory experiments designed to model the depth distribution of a lake with a shallow sidearm showed that the steady depth of the mixed layer depended on the ratio of the area of the shallow region to the area of the deep region. Significant stratification resulted only when the reservoir had shallow regions that account for more than 50 % of the surface area. The depth of the surface mixed layer also depended on the ratio of the depths of the shallow and deep regions and no significant stratification forms if this ratio is greater than 0.5. These results are in good agreement with observations of circulation and stratification during long periods of winter cooling from Chaffey reservoir, Australia. Theoretical time scales are also developed to predict the minimum duration of atmospheric cooling that can lead the development of stratification. ¶ In the second part of this thesis, I report a series of laboratory experiments which are designed to investigate the fine structure and buoyancy fluxes that result from salt finger convection in the presence of shear and intermittent turbulence. We find that, when salt finger convection in deep linear gradients is superposed with a depth-dependent spatially periodic shear, variations in the density profile develop on the same wavelength as the shear. The laboratory experiments presented in this thesis were carried out in a continuous density gradient with a spatially periodic shear produced by exciting a low-frequency baroclinic mode of vertical wavelength 60 mm. The density gradient consisted of opposing salt and sugar gradients favourable to salt fingers (an analogue to the oceanic heat/salt system). Where the shearing was large the salt finger buoyancy fluxes were small. Changes in salinity gradient due to the resulting flux divergence were self-amplifying until a steady state was reached in which the spatial variations in the ratio of salt and sugar gradients were such that the flux divergence vanished. Thus, along with reducing the mean salt finger buoyancy flux, a spatially varying shear can also lead to the formation of density structure. ¶ In the ocean intermittent turbulence can occur in isolated patches in salt finger-favourable regions. I present new results from laboratory experiments in which a partially mixed patch was produced in deep linear concentration gradients favourable to salt finger convection. Salt fingers give rise to an “up gradient” flux of buoyancy which can reduce the density gradient in a partially mixed patch. This can then lead to overturning convection of the partially mixed patch if a) the ratio of T and S gradients, R\rho =aTz/_ /betaSz, is near one, b) if turbulence results in a nearly well-mixed patch and c) the patch thickness is large enough that convective eddies are able to transport T and S faster than salt fingers. Once overturning occurs, subsequent turbulent entrainment can lead to growth of the patch thickness. Experimental results agree well with the theoretical prediction that h= \surd 8h B/N2 t, where h is the patch thickness, t is time, h is the mixing efficiency of turbulent entrainment, B is the buoyancy flux of the salt fingers and N is the buoyancy frequency of the ambient gradient region. This thickening is in contrast to the collapse that a partially mixed patch would experience due to lateral intrusion in a very wide tank. In regions of the ocean that contain salt fingers there is the possibility that, after a period of initial collapse, an intrusion could enter a regime where the rate of collapse in the vertical is balanced by the growth rate due to turbulent entrainment from the salt fingers buoyancy flux, thus tending to maintain the rate of lateral spread. ¶ A further series of laboratory experiments quantified the buoyancy fluxes that result from salt fingers and intermittent turbulence. A continuous density gradient, favourable to salt finger convection, was stirred intermittently by an array of vertical rods that move horizontally back and forth along the tank at a constant velocity. Previous experiments had found that continuous turbulence destroys any salt fingers present because the dissipation of turbulent kinetic energy occurs at scales that are generally smaller than salt fingers widths. However, when turbulence is present only intermittently, the salt fingers may have time to grow between turbulent events and so contribute to the vertical diffusivities of heat and salt. We conclude that the vertical buoyancy flux of salt fingers is strongly dependent upon the intermittency of the turbulence, and equilibrium fluxes are only achieved if the time between turbulent events is much greater than the e-folding time of the salt fingers. When these results are applied to an oceanographic setting, the effect of intermittent turbulence, occurring more 5% of the time, is to reduce the effective eddy diffusivity due to salt fingers below equilibrium salt finger values, so that at R\rho > > 2 the eddy diffusivity is due only to turbulence. The time averaged salt fingers fluxes are not significantly reduced by intermittent turbulence when R\rho > 2 or if the intermittence occurs less than 2% of the time, and so may contribute significant diapycnal fluxes in many parts of the ocean.

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