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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.
21

Experimental and numerical investigation of consolidation-induced solute transport

Lee, Jangguen, January 2007 (has links)
Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 198-210).
22

The effects of soil properties on the sorption of selected cephalosporin antibiotics

Miropolskiy, Reuven.. January 2009 (has links) (PDF)
Thesis (M.S. in chemical engineering)--Washington State University, December 2009. / Title from PDF title page (viewed on Jan. 20, 2010). "Department of Chemical Engineering and Bioengineering." Includes bibliographical references (p. 63-65).
23

Modeling of soil phosphorus sorption and control of phosphorus pollution with acid mine drainage floc

Sekhon, Bharpoor Singh. January 2002 (has links)
Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains xiv, 210 p. : ill. (some col.). Includes abstract. Includes bibliographical references.
24

Factors affecting diffusion of atmospheric fluorocarbons into unsaturated porous materials

Earp, Douglas E. (Douglas Eugene) January 1981 (has links)
No description available.
25

A relationship between inclusion content of soils and saturated hydraulic conductivity in laboratory tests /

Dunn, Anita Jean Austin. January 1983 (has links)
No description available.
26

A method for achieving efficient irrigation in moving sprinkler systems based on stationary "time to ponding" tests /

Fathollahzadeh, Fardad. Unknown Date (has links)
Surface runoff is one of the most important problems which occur with moving sprinkler irrigation systems: it is particularly severe in centre pivot systems operated at low pressure. The consequences of surface runoff are waste of water, lower irrigation efficiency, soil erosion and removal of fertilizers from the field. An obvious indicator of the potential for runoff to occur during sprinkler irrigation is the appearance of surface ponding. Indeed, results from a stationary "time to ponding" test (using a minimum set of three constant water application rates) carried out on the farm, is commonly used to determine the irrigation rate in moving systems. This practice sometimes leads to the occurrence of runoff under moving systems, particularly centre pivot systems. / The primary aim of the investigation was to explore the phenomenon of soil surface ponding in stationary "time to ponding" tests (using constant water application rate) and in moving sprinkler irrigation systems (using variable water application rate), and to discover the relationship between these two sets of conditions, in order to improve the design and managements of these systems and avoid runoff. / A vital component of the investigation was the development of a laboratory rig which incorporated certain characteristics and properties, including: A special soil test bed containing 355mm depth of a loamy sand soil, together with a system continuously measuring and monitoring soil moisture content. The rig also included heating and suction systems to reduce and establish target soil moisture conditions before each test, and an efficient drainage system. Ponding was identified in 15 circular depressions on the soil surface. A water application simulator capable of being operated in both stationary and moving modes at different speeds, applying different constant and variable irrigation rates to the soil test bed with very small droplets. The nature of the supply closely approximated that of field installations. A continuous water application measurement device capable of measuring instantaneous water application rate and pattern as well as irrigation depth applied to the soil test bed. / Certain parameters, of necessity, were fixed for the investigation: these included the soil, the type of variable application pattern (parabolic), the range of speeds of the moving simulator (10% to 100% of maximum speed which was 345mm/minute) and the range of initial soil moistures (3% up to field capacity). Initial tests were carried out to determine a suitable water application rate: this was set as 103mm/h (average). The main set of tests was carried out using this average application rate under constant ("time to ponding") and variable ("onset of ponding") irrigation conditions at different soil moisture contents. / The main outcome of the research was that the maximum irrigation depth that can be applied by a moving system (variable pattern) without the appearance of ponding for any set value of initial soil moisture, is significantly less than the maximum irrigation depth which must be applied to produce ponding in a stationary system (constant pattern), operated with the same initial soil moisture and same average application rate. Therefore, the results obtained from a “time to ponding” test, if applied directly, overestimate the optimum water application rate and also the maximum irrigation depth which can be applied in moving irrigation systems, if they are to operate efficiently. / A relationship was established between the two sets of outcomes for corresponding soil and water application rate and pattern conditions. The apparatus and the method can be used for further research to discover similar relationships for different soil types and different water application rates and patterns in order to provide a general model. This model can be used to modify the optimum water application rate (obtained directly from stationary "time to ponding" tests) and, also, the maximum irrigation depth (through choice of speed appropriate to the initial soil moisture) in moving sprinkler irrigation systems, particularly in centre pivot systems. / Thesis (PhDCivilEngineering)--University of South Australia, 2005.
27

Rainfall infiltration characteristics for a semi-arid watershed soil

Morse, John Gray, January 1976 (has links) (PDF)
Thesis (M.S. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references.
28

Spatial and temporal patterns in soil moisture variations in Oklahoma and its comparison with ETA Model

Park, Gi-hyeon. January 2000 (has links) (PDF)
Thesis (M.S. - Hydrology and Water Resources) - University of Arizona. / Includes bibliographical references (leaves 74-
29

Generation of water repellence in sands, and its amelioration by clay addition /

Ward, Philip R. January 1993 (has links) (PDF)
Thesis (Ph.D.)--University of Adelaide, Department of Soil Science,1993.
30

Characteristics and sorption properties of charcoal in soil with a specific study of the charcoal in an arid region soil of Western Australia /

McMahon, Claire Louise. January 2006 (has links)
Thesis (M.Sc.)--University of Western Australia, 2006.

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