Now showing items 7137-7156 of 15082

    • Hydrodynamic analysis of electron-beam heated UO₂ vaporization experiments

      Clark, Bradley Allan (The University of Arizona., 1979)
    • A hydrodynamic evaluation of the Sandia UO₂ equation of state experiment

      Smith, Mark Scott (The University of Arizona., 1981)
    • Hydrodynamic Optimization of the AirAccordion Photobioreactor for Microalgae Production

      Cuello, Joel; He, Shiwei; Slack, Donald; Fitzsimmons, Kevin (The University of Arizona., 2016)
      Algae are a prolific source of biochemicals with economic importance, including nutraceuticals, biofuels, animal feed, etc. The general aim of this study was to establish how the hydrodynamic conditions generated within specific types or designs of photobioreactors determine their respective algae growth. The specific objectives of this study were: (1) To determine and compare key hydrodynamic parameters in the Air Accordion photobioreactor and the conventional bubble column, including Residence Time, Vessel Dispersion Number, Bodenstein Number, Mixing Time and oxygen liquid mass transfer coefficient (kla); and, (2) To test how differences in the hydrodynamic conditions would result in significant difference in growths of the green alga Scenedesmus obliquuus between the photobioreactors. The results of the study showed that: (1) The Residence Time of 566 s for the Air Accordion significantly exceeded by 28% that of 444 s for the bubble column, signifying greater liquid mixing in the Air Accordion; (2) The Vessel Dispersion Number for the Air Accordion of 0.168 significantly exceeded that for the bubble column of 0.166, indicating greater degree of mixing in the Air Accordion than in the bubble column; (3) The Mixing Time in both the Air Accordion and the bubble column declined as the air flow rate increased, indicating that the tracer ions in both photobioreactors mixed more quickly. For each of the flow rates tested, however, the mixing time for the bubble column significantly exceeded that for the Air Accordion, indicating that liquid mixing in the Air Accordion occured significantly quicker than in the bubble column. At 1.0 LPM, the bubble column's Mixing Time of 10 s exceeded by 25% that of the Air Accordion of 8 s; (4) The oxygen liquid mass transfer coefficients in both photobioreactors increased as the air flow rate increased, indicating that the transfer of oxygen from the air bubbles into the liquid within the photobioreactors gained efficiency. For each of the air flow rates tested, however, the oxygen liquid mass transfer coefficient for the Air Accordion significantly exceeded that for the bubble column, indicating a significantly more efficient oxygenation of the liquid in the Air Accordion occurring than in the bubble column. At 1.0 LPM, the Air Accordion's oxygen liquid mass transfer coefficient of 0.00138 s⁻¹ exceeded by 48% that of the bubble column of 0.000931 s⁻¹; and (5) The growth of Scenedesmus obliquus in the Air Accordion significantly exceeded that in the bubble column for both 0.1 LPM and 1.0 LPM. The final algae density of 0.25 g DW/L in the Air Accordion significantly exceeded by 31% that of 0.18 g DW/L in the bubble column at 0.1 LPM. Similarly, the final algae density of 0.37 g DW/L in the Air Accordion significantly exceeded by 19% that of 0.31 g DW/L in the bubble column at 1.0 LPM. Thus, the growth of Scenedesmus obliquus in the Air Accordion photobioreactor -- with significanlty more favorable hydrodynamic characteristics in terms of Residence Time, Vessel Dispersion Number, Mixing Time and oxygen liquid mass transfer coefficient -- significantly exceeded algae growth in the bubble column of the same volume and under the same environmetal conditons.
    • Hydrogen ion concentrations in ore pulps

      Brooks, Theodore Thomas, 1917- (The University of Arizona., 1943)
    • Hydrogen sulfide in sewers

      Johnson, Joel Amobi, 1941- (The University of Arizona., 1968)
    • Hydrogeochemical Controls on Microbial Coalbed Methane Accumulations in the Williston Basin, North Dakota

      McIntosh, Jennifer C.; Pantano, Christopher Patrick; Ferre, Paul A.; Meixner, Thomas (The University of Arizona., 2012)
      Extensive research has been conducted in numerous coalbed methane (CBM) basins; however, the Williston Basin (WB) remains largely unexamined due to the absence of CBM production despite large coal reserves. CBM in WB coalbeds has been reported, but there has been no systematic study on gas origin and distribution, or hydrogeochemical controls on gas generation to date. This study aims to determine differences in chemistry between groundwaters with and without the presence of CH₄ to better understand factors affecting CBM generation. Results reveal that shallow gas accumulations in WB coalbeds are microbial in origin and formed via CO₂ reduction. CBM is associated with Na-HCO₃ type groundwater with SO₄ concentrations<1 mmole/L due to cation exchange and sulfate reduction, respectively. These groundwaters occur in deeper units of the Fort Union Formation, underlying multiple coalbeds, suggesting that CH₄ is present in waters that have reacted extensively with formations containing low-rank (lignite) coals.
    • A hydrogeochemical evaluation of the lower Cienega Creek sub-basin, Pima County, Arizona

      Conklin, Martha H.; Grahn, Howard Lance; Conklin, Martha H.; Bassett, R. L. (The University of Arizona., 1995)
      Mass transport modeling of ground and surface waters upstream of perennial Cienega Creek, Arizona, delineate processes which control ground water chemistry in this arid alluvial basin. NETPATH modeling shows that the aquifer is open to CO2 flux, and that dissolution of gypsum, redistribution of carbonate minerals, and cation exchange of Ca2+ for Na+, control the evolution of ground and surface water chemistry. Calcium bicarbonate waters which recharge the basin margin, evolve to calcium-sulfate waters during passage through the alluvial aquifer, and produce a quantifiable chemical evolution of ground water within the aquifer. Evaluation of a 10-year data base, plus the clarification of controlling chemical processes, allow a reinterpretation of the source of Cienega Creek waters, which is shown in this study to be the upstream alluvial basin. These findings are partially corroborated by an associated geophysical study which confirms a basin flow pattern parallel to the flow path assumed by this investigation.
    • Hydrogeochemical Modeling of Western Mountain Front Recharge, Upper Cienega Creek Sub-Basin, Pima County, Arizona

      Conklin, Martha; Huth, Hans Jarlath (The University of Arizona., 1997)
      Using historical and current water quality data, the geochemical processes responsible for controlling the chemical evolution of groundwater in the Upper Cienega Creek Basin are characterized and modeled. Spatially, waters evolve from a calcium-bicarbonate type at the mountain front to a sodium-bicarbonate type in the central basin. Analyses for Cienega Creek perennial flows demonstrate a relatively high sodium concentration (greater than 1.71 mmol/l) characteristic of central basin groundwaters. Given the similar high sodium signature, it is assumed that surface and groundwaters evolve under the same geochemical controls while originating from the same mountain-front recharge sources. Mass balance modeling demonstrates that the chemical processes controlling water quality in the Upper Cienega Creek Basin are typical of alluvial basins in the Southwest (Robertson, 1991).
    • The hydrogeochemistry of strontium in the Ranegras Plain groundwater basin

      Dolegowski, John Richard,1951-; Simpson, Eugene S.; Davis, Stan N.; Long, Austin (The University of Arizona., 1988)
      The occurrence, sources, and governing geochemical reactions of strontium in the groundwater of the Ranegras Plain basin, western Arizona, were evaluated by the analysis of basin geology, groundwater quality data, and chemical analyses of basin drill cuttings and potential strontium source rocks from the surrounding mountains. Four potential mechanisms controlling the hydrogeochemistry of strontium were evaluated: (1) celestite and strontianite dissolution; (2) strontium release during the weathering of silicate minerals; (3) the solid solution of strontium in calcite, aragonite, and gypsum; and (4) cation exchange. Evaporite dissolution, aluminosilicate mineral hydrolysis, calcite precipitation, and cation exchange control the basin hydrogeochemistry. Strontium concentrations in groundwater range from 0.060 to 4.4 milligrams per liter and are controlled primarily by pH, gypsum dissolution and calcite precipitation of which strontium is a trace component, and the cation exchange of strontium on aquifer minerals.
    • Hydrogeologic evaluation of the Sonoita Creek aquifer

      Bradbeer, Gayle Elizabeth,1953-; Evans, Daniel D. (The University of Arizona., 1978)
      This study examines the potential of the area along Sonoita Creek upstream from Rio Rico, Arizona, 8-1/2 miles to Lake Patagonia dam, for water production from the shallow alluvial Sonoita Creek aquifer using geologic and hydrologic surveys made in 1977. The aquifer was divided into two geographical regions. Sources of recharge to and discharge from each region were examined and a quantitative water budget was made for each region. The three potential sources of water, the extractable stored volume, the rejected recharge, and the natural discharge were quantified, and the feasibility of exploiting each was discussed, for an emergency supply and for a sustained yield production.
    • Hydrogeologic field study of the Koongarra Uranium Deposit in the Northern Territory of Australia

      Marley, Robert Douglas,1962-; Davis, Stanley N. (The University of Arizona., 1990)
      Water level, aquifer test, and slug-test data indicate that the Koongarra uranium deposit is within a low permeability, semi-confined, fractured-schist aquifer. Water levels demonstrate semi-diurnal and diurnal fluctuations related to earth tides and evapotranspiration stresses. Hydraulic test data were analyzed with homogenous isotropic and homogenous anisotropic models which allowed parameter estimation for sub-regions of the study area. Dominant anisotropy is subparallel to lithologic layering and the reverse fault. Slug tests reveal regions controlled by low storage but highly conductive fractures and isolated regions of low conductivity. Hydraulic connection of the weathered zone with the underlying schist is dependent on clay content and fractures. Environmental isotopes indicate ground water has been isolated from the atmosphere for at least 40 years and possibly several thousand years in some locations. Water budget calculations indicate the majority of recharge must be from direct infiltration through the weathered profile to account for the calculated ground-water fluxes.
    • Hydrogeologic investigations for a groundwater contamination site Phoenix, Arizona

      Hall, Dennis Gregory, 1954- (The University of Arizona., 1991)
    • A hydrogeologic resource assessment of the lower Babocomari Watershed, Arizona

      Schwartzman, Peter N.,1961- (The University of Arizona., 1990)
      Perennial streamflow and a rich riparian habitat along portions of the Babocomari River is supported by the regional ground-water system. A hydrologic resource assessment of the lower Babocomari Watershed (upper San Pedro Basin, Arizona) was performed to characterize the system which supports the current flow regime of the river, and estimate the effects of future pumping on hydrologic conditions along the river. Descriptions of the physiography, climate, vegetation, and geology of the study area were primarily derived from literature review. Descriptions of the ground-water system, surface-water system, surface-water/ground-water interaction, riparian vegetation, and water quality were chiefly derived from field work and laboratory analysis. Descriptions were substantiated with flow-net, water-budget, and aquifer-test analyses. Current and predicted future rates of pumping were quantified, and were used to make preliminary analytical estimations of drawdown effects on hydrologic conditions along the Babocomari River.
    • Hydrogeological analysis of groundwater flow in Sonoita Creek basin, Santa Cruz County, Arizona

      Nassereddin, Muhamad Taher,1933-; Harshbarger, J. W.; Pye, W. D.; Wright, J. J. (The University of Arizona., 1967)
      The Sonoita Creek basin lies in a north trending intermontane valley in southeastern Arizona. Mature dissected mountains rise abruptly from long alluvial slopes and culminate in peaks ranging from 1000 to 1300 feet above the valley floor. The mountains surrounding the alluvial sediments are of volcanic rocks of Miocene ? age, and have been subjected to tectonic disturbance which resulted in extensive faulting, folding, and the formation of joint systems. The alluvial sediments have been divided into five units based on their stratigraphic position, structural involvement, lithology, and permeability. The oldest unit in the basin is unit No. 5 and the youngest is unit No. 1. Groundwater supplies of the Sonoita Creek basin are developed largely from alluvial unit No. 4, and minor supplies from alluvial unit No. 1. The groundwater originates as precipitation on the mountain areas and on the floor of the valley. The average rainfall on the valley floor is about 20 inches per year while on the mountains it is more than 50 inches per year. A minor part of the groundwater recharge is from the discharge of Monkey spring into the northern part of the basin. Groundwater is discharged from the Sonoita Creek basin through evaporation, as effluent flow of about 7 cubic feet per second through Sonoita Creek, and by artificial discharge through pumping. The perennial streamflow in Sonoita Creek near Patagonia is due to the impervious volcanic rocks in the subsurface, which crop out 500 feet south of the town, forcing the groundwater to discharge at the surface. Groundwater in the basin is generally of excellent to good quality for irrigation use, and medium to good for domestic purposes. The groundwater contains high percentages of sulphate, calcium, and bicarbonates.
    • A hydrogeological evaluation and feasibility analysis of artificial groundwater recharge and recovery in eastern Pauba Valley, Riverside County, California

      Neuman, Shlomo P.; Phraner, Ralph Wilson, 1950- (The University of Arizona., 1991)
      The Rancho California Water District has an opportunity to conjunctively manage available ground, surface, imported, and reclaimed water resources through a program of artificial recharge and recovery. The site of proposed operations is eastern Pauba Valley, Riverside County, California. Hydrogeological analyses were conducted to identify valley aquifers, evaluate hydraulic properties and quantify ground water storage, movement and yield. Field studies included nine aquifer tests, a survey of well locations and construction of five monitoring wells. All data collected were entered into a computerized Water Resources Information Management System (WRIMS) custom configured for the project. A finite-difference computer simulation model was constructed to evaluate the feasibility and facilities requirements of two alternative recharge and recovery programs. Computer simulation results confirm the feasibility of 9,000 and 18,000 acre feet per year recharge and recovery programs.
    • Hydrogeological study and evaluation of water resources of the Collo Basin, Skikda, Algeria

      Beloulou, Laroussi,1959-; Buras, Nathan; Evans, Daniel D.; Davis, Donald R. (The University of Arizona., 1987)
      The Collo Basin, a small coastal aquifer, consists of three different alluvial units characterized by different hydraulic properties. If adequately managed, alluvial unit No. 3, being the best aquifer, is capable to supply domestic water for the city of Collo in the short and the long run as well. The estimated rate of water withdrawal from unit No. 3 exceeds more or less that of direct recharge by precipitation, causing hence a lowering of the water table. Consequently, recent chemical analyses of water samples show that groundwater is, to some extent, further contaminated by sea water. Therfore, it is time for local authorities to take some legal measures prohibiting any additional well drillings in this area as to prevent a possible disaster until all hydrological parameters are identified with certain degree of accuracy.
    • Hydrogeology and a quantitative model to predict a safe yield for the area of Villa Juarez, Durango, Mexico

      Flores Castro, Sergio Alejandro,1951-; Ince, Simon; Guertin, D. Phillip; Fogel, Martin M. (The University of Arizona., 1987)
      The Villa Juarez, Durango, area was selected as the appropriate location for constructing an electrical generating plant. Although it has been determined that the water supply is adequate for the present time, it is necessary to determine whether this supply will be adequate for operation of the electrical plant during a period of 20 years. A groundwater model was used to predict the safe yield in the study area. The groundwater demand will be 300 L/s, plus that extracted from the unconfined aquifer in the Villa Juarez area. The total pumpage will be 151,454 m³/d in 1988. The predicted drop in water levels will be between 4 and 7 m, depending on the well location. In areas distant from the river the water level is predicted to drop about 13 m. Considering the available data, very good agreement was found between observed and simulated water levels during the calibration period, and the results of the prediction period are reliable.
    • The hydrogeology and development of the ground water resources in the El Asentamiento Campesino El Cortijo, Estado Aragua, Venezuela.

      Marquez Oropeza, Romulo,1938-; Wright, Jerome J.; Simpson, Eugene Sidney; Pye, Willard Dickison (The University of Arizona., 1970)
      This thesis pertains to the ground water resources of the E1 Asentamiento Campesino E1 Cortijo area, which is located within the mountain ranges of north-central Venezuela, South America. The area described in this thesis is an agricultural area of 400 hectares (1,000 acres) lying in a basin of 2,100 hectares (5,187 acres). The sediments underlying the area consist of about 100 meters (328 feet) of gravel, sand and clay of Quaternary age and are bounded on the north and south by relatively impermeable metamorphic rocks. The purpose of the investigation was to determine and to describe the ground water conditions in the mentioned area with special emphasis on the development of the ground water resources. The sources and movement of ground water, the recharge and discharge relations and the effects of pumping on the water levels are described. Ground water occurs under water table conditions and precipitation and unqerf10w represent the sources of recharge to the aquifer. The coefficients of transmissibility and storage were estimated to be 1,800 cubic meters per day (154,700 g./d./ft.), and 0.11 respectively. Water quality is satisfactory for irrigation use, but concentrations of turbidity, apparent color and dissolved-iron exceed the amount recommended by the United States Public Health Service for drinking purposes.
    • Hydrogeology and groundwater development in a salar basin in the Andes Mountains of northern Chile

      Harshbarger, John W.; Montgomery, Errol L.; Victor, William Ray,1953-; Simpson, Eugene S.; Simpson, Eugene S.; Evans, Daniel D. (The University of Arizona., 1986)
      A closed salar basin, 4,100 to more than 5,350 meters above mean sea level, is a potential source of fresh groundwater for proposed mining operations in the arid Andes Mountains of northern Chile. The prolific basin aquifer, comprised of alluvial deposits underlain by fractured ignimbrite, occurs over an area of 23 square kilometers. Transmissivity ranges from 20 to 7,100 square meters per day. Volume of potentially recoverable groundwater is equal to a constant yield of 200 liters per second for 30 years. Groundwater discharge occurs via evaporation at the salar, and is in approximate equilibrium with groundwater recharge. Projected long-term combined pumping rate from two proposed production wells is 164 liters per second. This pumping rate is in the same magnitude as evaporation at the salar. Proposed pumping would diminish surface water supplies in the basin, and would result in a new dynamic equilibrium for the groundwater system.
    • Hydrogeology and groundwater modeling study of the Azua Valley, Dominican Republic

      Pérez Pérez, Odalís, 1950- (The University of Arizona., 1989)
      The results of the model can be used for enhancing the integrated management of the water resources of the Azua Valley. The model shows the effects of an extensive drainage network on the high ground-water levels which prevailed from 1983 to 1988. A sensitivity analysis also shows the zones of the aquifer which require development of new pumpage in order to overcome the drainage problem in areas still flooded by uncontrolled artesian flow. The results of the model can be used for enhancing the integrated management of the water resources of the Azua Valley.