Thesis (M.S.)--University of Missouri, School of Mines and Metallurgy, 1933. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed July 12, 2010) Includes bibliographical references (p. 55) and index (p. 56).

Project Completion Report, OWRT Project No. A-091-ARIZ / Agreement No. 14-34-0001-8003 / Project Dates: October 1978 - September 1979 / Acknowledgement: The work upon which this report is based was supported by funds provided by the United States Department of the Interior, Office of Water Research and Technology, as authorized under the Water Resources Research Act of 1978. / This report contains the results of a one year study to develop improved methods of evaporation control using wax impregnated foam. The foam used was expanded polystyrene and the wax used was paraffin with a 140° F melting point. The report tells of a pressure chamber that was used to wax impregnate sheets of expanded polystyrene. Based on tests made in the laboratory the pressure chamber was modified into a vacuum chamber. Problems were encountered getting the interior of the sheets impregnated using a vacuum. There was no way this problem could have been predicted based on the smaller laboratory models. The pressure method, however, was successfully used to impregnate up to 3 -inch thick sheets of expanded polystyrene. During the project it was found that the paraffin impregnated rafts worked very well until high temperatures, 100° F plus, are encountered Under dusty conditions. The heat causes the surface of the wax to get tacky, the dust darkens the otherwise white surface, which in turn captures more heat, and then more dust, etc. The high surface temperature caused an accelerated weathering of the material. Because of this, waxes with higher melting points were tried. Additional work is needed in this area as no satisfactory combinations were found. Two polyethylene copolymers with a melting point close to the 190° F destruction point of the expanded polystyrene were tested. This wax was too viscous for impregnation but provided a hard surface coating when the previously wax impregnated expanded polystyrene is dipped into the molten polyethylene wax. This dipping might be the best method for surface protection at low cost but additional testing is needed before trying the material out on a large scale. Progress was made in the development of wax impregnated lightweight concrete rafts. The wax impregnation of the lightweight raft solves the vapor penetration problem. This type of raft was found to resist removal by wind and weathered very well in the one year of testing. Connecting rafts with strips of sheet metal bonded to the expanded polystyrene was done on a small scale, and needs to be field tested. The PVC pipe C clamps work well on partially submerged rafts but need to be lengthened to interconnect wax impregnated rafts. Square wax impregnated rafts lx1 ft in size did not stay on a small test pond in high wind. Circles are presently being tried but additional testing is needed in this area before their reliability is known.

The purpose of this thesis is to determine the effect of hexadecanol on the populations of Pseudomonas and Alcaligenes species in reservoirs and determine their ability to utilize this compound as a carbon source.

M.A. (Geography and Environmental Management) / Water can be regarded as a scarce commodity in South Africa and one cannot rely solely on the discovery of new water resources to meet the ever increasing demands. Water is arguably the most precious resource in South Africa and its proper management in all spheres of activity is imperative ( Middleton and Stern,1987 ). This is no different in the mining industry where a primary consumptive use of water is in the tailings dams and associated return water. Restricted implementation of Government water plans and a series of droughts has forced users of water to optimise their use of water. A key to correct water management of a tailings disposal system on a gold mine lies in accurate and meaningful water balance. To provide an accurate water balance, quantifying the water loss is necessary. The water loss in a tailings system is mainly due to evaporation and interstitial flow. For the purpose of this study, evaporation is dealt with in more detail.

From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / Mulches have been used for evaporation suppression in facilitating vegetable production under arid lands conditions. A study was undertaken in order to evaluate the effectiveness of plastic aprons, supplied by the FAO, as compared to gravel mulches. The vinyl aprons were 6 mils thick and about 1 meter square. Squash plants (Cucurbita pepo) were planted with gravel or plastic aprons or in bare areas and under different watering schedules. The yields under plastic aprons were considerably greater than under gravel and required slightly less water. Bare soil yields lagged far behind. Soil temperatures under the plastic aprons were consistently higher over 24 hours than bare soil, which within limits, would facilitate faster crop growth. Additionally, the apron collects and diverts rainfall to the plant. The vinyl used lasts only 2 seasons, and gravel would probably be a more suitable mulch for developing countries where capital is scarce.

From the Proceedings of the 1978 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 14-15, 1978, Flagstaff, Arizona / The compartmented reservoir is presented as an efficient method of storing water in areas of Arizona having a relatively flat terrain where there is a significant water loss through evaporation. The flat terrain makes it difficult to avoid large surface- area-to-water-volume ratios when using a conventional reservoir. Large water losses through evaporation can be reduced by compartmentalizing shallow impervious reservoirs and in flat terrain concentrating water by pumping it from one compartment to another. Concentrating the water reduces the surface-area-to-water-volume ratio to a minimum, thus decreasing evaporation losses by reducing both the temperature and exposure of the water to the atmosphere. Portable, high-capacity pumps make the method economical for small reservoirs as well as for relatively large reservoirs. Further, the amount of water available for beneficial consumption is usually more than the amount of water pumped for concentration. A Compartmented Reservoir Optimization Program (CROP-76) has been developed for selecting the optimal design configuration. The program has been utilized in designing several systems including several in Arizona. Through the use of the model, the interrelationship of the parameters have been determined. These parameters are volume, area, depth, and slope of the embankment around each compartment. These parameters interface with the parameters describing rainfall and hydrologic characteristics of the watershed. The water -yield model used in CROP-76 requires inputs of watershed area, daily precipitation and daily and maximum depletion. In addition, three sets of seasonal modifying coefficients are required either through calibration or estimated by an experienced hydrologist. The model can determine runoff from two types of watersheds, a natural and /or treated catchment. Additional inputs of CROP-76 are the surface water evaporation rate and the amount and type of consumptive use.