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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.
41

Spatial variability in soils stiffness and strength /

Kim, Hyunki. January 2005 (has links)
Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2006. / Mayne, Paul, Committee Member ; Frost, David, Committee Member ; Santamarina, Carlos, Committee Chair ; Rix, Glenn, Committee Member ; Ruppel, Carolyn, Committee Member.
42

Genesis of some soils associated with low and big sagebrush complexes in the Brown, Chestnut, and Chernozem-Prairie zones in southcentral and southwestern Idaho

Fosberg, Maynard A. January 1963 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1963. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
43

A pedo-ecological study of soil genesis in the tropics from sea level to eternal snow, Star Mountains, central New Guinea

Reijnders, Johan Jacob, January 1964 (has links)
Proefschrift--Rijksuniversiteit. / "Stellingen" (1 leaf) inserted. Bibliography: p. [154]-159.
44

Field measurements of the linear and nonlinear shear moduli of soils using drilled shafts as dynamic cylindrical sources

Kurtulus, Asli, January 1900 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.
45

The lure of pedogenesis : an anthropological foray into making urban soils in contemporary France

Meulemans, Germain January 2017 (has links)
This thesis is an anthropological inquiry into the emergence of urban soils as matters of concern in the worlds of soil scientists and other fields more traditionally involved with cities. Through the lens of soil-making practices, it seeks to elucidate the specificity of urban pedogenesis, including the growth of soils and the lives of the humans associated with them. City soils have typically been neglected in modern thinking about nature and urbanism. They have long been framed solely as a technical question for engineers which seemed to require no further pondering until – in the last two decades – they entered the scope of the soil sciences. This thesis draws on over thirteen months of multi-locale fieldwork conducted in Paris and Lorraine with soil scientists, gardeners and foundation builders. The research does not define a priori what should count as 'urban', 'agricultural' or 'natural' soils. Building on scholarship in anthropology, the soil sciences, science studies, and speculative philosophy, it follows how these actors learn to be affected in the material performance of different relations between people and soils. The chapters are built in counterpoint to one another, occasionally turning to narrative to complement analysis and more traditional ethnography. Each chapter pulls a different diffractive string from the mesh of urban soil matters, and follows where it leads. As ways of knowing that emerge from soil construction are described, the question of what making soils does to knowing them becomes a central thread of the thesis. In this, it looks at how soils participate in apparatuses where they become 'lures for feelings' – affective interweavings in which worlds are experienced.
46

Deployment of calcium polysulphide for the remediation of chromite ore processing residue

Anunike, Chidinma January 2015 (has links)
Chromium contamination of groundwater and soils continues to pose a major environmental concern. Soils may have become contaminated with chromium through former industrial activities geochemical enrichment. The nature of the industrial activity will determine the form and concentration of the chromium as well as the presence of co-contaminants and the pH and redox of the soil. Chemical reductants have been widely used for the transformation of hexavalent chromium in the environment. Over recent decades attention focused on the chemical reductant calcium polysulphide which has performed effectively in the treatment of groundwater and soil samples contaminated with Cr(VI). Yet a detailed understanding of calcium polysulphide (CaSx) performance has not yet been established. Hexavalent chromium concentrations in aqueous and groundwater samples were significantly reduced by calcium polysulphide and CaSx:chromate molar ratio of 1.5 was sufficient to prevent partitioning of Cr(VI) into solution and to precipitate the solution phase. Calcium polysulphide was used for the remediation of solid chromite ore processing residue (COPR) samples. Prior to the application of calcium polysulphide to COPR, each of the key steps were optimized. A range-finding experiment was conducted to understand the dosage and treatment regime at which Cr(VI) immobilization within COPR was optimal. The results indicated that unsaturated deployment of CaSx into the medium outperformed that in saturated systems. A higher polysulphide amendment dose of 5% w/v concentration enhanced the final treatment of Cr(VI) within COPR. The toxicity and carcinogenicity of Cr(VI) over Cr(III) requires a technique capable of discriminating between valencies. The EPA Method 7196A specifically quantifies the concentrations of Cr(VI) in environmental samples and was used for all analysis to differentiate between Cr(VI) and Cr(III). Cr(III) was calculated as the difference between the Cr(VI) and Cr-total concentrations. In addition to the EPA 7196A, a novel ion exchange resin (IER) procedure was developed to differentiate the two species of chromium. After optimisation, Amberlite resins IRA 400 and IR-120 were used for the specific sorption and subsequent analysis of aqueous Cr(VI) and Cr(III) solutions. For the selective removal of chromate from groundwater, waste water and soil samples, Amberlite IRA 400 achieved a consistent performance of >97% removal in a range of trials. The IERs in this work were applied as analytical tools however they could be applied as remediation tools. While aqueous treatment of chromium contaminated media using CaSx was very successful, COPR treatment proved to be difficult due to the complex nature of the system. An understanding of stoichiometric responses to CaSX has been established, but the nuances of soil physicochemical interactions require more thorough investigation.
47

The influence of spatial variability on the geotechnical design properties of a stiff, overconsolidated clay.

Jaksa, Mark B January 1995 (has links)
The research presented in this thesis focuses on the spatial variability of the Keswick and Hindmarsh Clays within the Adelaide city area. Keswick Clay is locally significant since many of Adelaide's multi-storey buildings are founded directly on it, and internationally significant, since it has been shown by Cox (1970), that this clay exhibits remarkably similar properties to those of the well-documented London Clay. The assessment of the small-scale variability of the undrained shear strength of these clays is based on measurements obtained using the electrical cone penetration test (CPT), and a micro-computer based data acquisition system, designed specifically for this study. A significant feature of the data acquisition system is that it enables measurements to be obtained at intervals of 5 mm, both reliably and efficiently. The development of the data acquisition system is discussed, and the accuracy of its measurements is examined. The small-scale variability of the undrained shear strength of the Keswick Clay is based on more than 200 vertical CPTs, performed within an area of 50 X 50 metres at a site located in the Adelaide city area. The CPTs were spaced at lateral intervals varying between 0.5 and 5 metres, with each vertical CPT extending to a typical depth of 5 metres. In addition, the small-scale horizontal spatial variability of the Keswick Clay is examined using an electrical cone penetrometer driven horizontally into the face of an embankment, again located within the Adelaide city area. The accuracy of the CPT measurements is examined, and discussion is given of the shortcomings associated with a commonly used technique, by Baecher (1982), for estimating the random measurement error associated with various test procedures. The assessment of the large-scale spatial variability of the undrained shear strength of the Keswick and Hindmarsh Clays is founded on a data base of geotechnical engineering properties, compiled from a number of consulting engineering practices and government instrumentalities. The data base, known as KESWICK, contains approximately 160 site investigations, 380 boreholes, and 10,140 measurements obtained from a number of different laboratory and in situ tests. In addition, KESWICK is used to establish generalised trends and bounds, associated with the various geotechnical engineering design properties contained within the data base. The techniques of random field theory and geostatistics are used to quantify, model and predict the spatial variability of the Keswick and Hindmarsh Clays. These techniques are compared with one another in order to assess the suitability and shortcomings of each, when applied to the study of the spatial variability of geotechnical engineering materials. Furthermore, a number of specifically-written computer programs, which were developed to enable the various spatial variability analyses to be performed, are discussed. It is demonstrated that the lateral undrained shear strength of the Keswick Clay, within the Adelaide city area, exhibits a nested structure; that is, one which is the compound effect of several genetic sources of spatial variation. In addition, it is shown that this nested structure can be adequately modelled by means of a spherical semivariogram model. The nested structure is used, together with the kriging estimation process, to provide preliminary estimates of the undrained shear strength of the Keswick Clay, within the Adelaide city area. The analyses demonstrate that the nested model and the kriging process provide a useful facility for generating preliminary estimates of the strength of the clay. Finally, the significance of the spatial variability of the undrained shear strength of clay soils is examined, with reference to the design of embankments and pile foundations. It is demonstrated that the correlation distance can greatly influence the design of each of these geotechnical systems. / Thesis (Ph.D.)--Dept. of Civil and Environmental Engineering, 1995.
48

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).
49

Terrestrial biotic ligand model (TBLM) for copper, and nickel toxicities to plants, invertebrates, and microbes in soils

Thakali, Sagar. January 2006 (has links)
Thesis (Ph.D.)--University of Delaware, 2006. / Principal faculty advisor: Herbert E. Allen, Dept. of Civil & Environmental Engineering. Includes bibliographical references.
50

Effects of cow urine and its constituents on soil microbial populations and nitrous oxide emissions : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy at Lincoln University /

Bertram, Janet. January 2009 (has links)
Thesis (Ph. D.) -- Lincoln University, 2009. / Also available via the World Wide Web.

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