Irrigation water of poor quality can have deleterious effects on soils. However, the effect of drip irrigation on seasonal and long term (e.g. over 50 years) changes in soil chemical properties is poorly understood, complicated by the two-dimensional water flow patterns beneath drippers. Field and laboratory experiments were conducted, along with computer modelling, to evaluate morphological and physio-chemical changes in a typical Barossa Valley Red Brown Earth (Palexeralf, Chromosol or Lixisol) when drip irrigated under various changing management practices. This work focused on the following two management changes : (i) switching from long-term irrigation with a saline source to less saline water and (ii) gypsum (CaSO₄) application. A literature review (Chapter 1) focuses on the distribution, features, properties and management of Red Brown Earths in the premium viticultural regions of the Barossa Valley and McLaren Vale, South Australia. The effects of irrigation method and water quality on the rate and extent of soil deterioration are emphasised. The review also discusses the irrigation of grapes (Vitis vinifera) and summarises previous research into the effect of sodicity and salinity on grape and wine characteristics. This chapter shows the importance of Red Brown Earths to Australian viticulture, but highlights their susceptibility to chemical and physical degradation. Degradation may be prevented or remediated by increasing organic matter levels, applying gypsum, modifying cropping and through tillage practices such as deep ripping. Chapter 2 provides general information on the two study sites investigated, one in the Barossa Valley and the other at McLaren Vale. Local climate, geology, geomorphology and soils are described. Chapter 3 details laboratory, field and sampling methods used to elucidate changes in soil chemical and physical properties following irrigation. The genesis of the non-irrigated Red Brown Earth in the Barossa Valley is described in Chapter 4, and is inferred from geochemical, soil chemical, layer silicate and carbonate mineralogical data. Elemental gain and loss calculations showed 42% of original parent material mass was lost during the formation of A and A2 horizons, while the Bt1 and Bt2 horizons gained 50% of original parent material mass. This is consistent with substrate weathering and illuviation of clay from surface to lower horizons. The depth distributions of all major elements were similar ; the A horizon contained lower amounts of major elements than the remainder of the profile, indicating this region was intensely weathered. This chapter also compares the non-irrigated site to the adjacent irrigated site (separated by 10 m) to determine if the sites are pedogenically identical and geochemical changes from irrigation. Many of the differences between the non-irrigated and irrigated sites appear to be correlated with variations in quartz, clay, Fe oxide and carbonate contents, with little geological variation between the sample sites. In Chapter 5 morphological, chemical and physical properties of a non-irrigated and irrigated Red Brown Earth in the Barossa Valley are compared. Alternating applications of saline irrigation water (in summer) and non-saline rain water (in winter) have caused an increase in electrical conductivity (EC [subscript se]), sodium adsorption ratio (SAR), bulk density (ρ b) and pH. This has resulted in enhanced clay dispersion and migration. Impacts on SAR and ρ b are more pronounced at points away from the dripper due to the presence of an argillic horizon, which has greatly influenced the variations in these soil properties with depth and distance from the dripper. Dispersion and migration of clay were promoted by alternating levels of EC, while SAR remained relatively constant, resulting in the formation of a less permeable layer in the Bt1 horizon. Clay dispersion (breakdown of micro-aggregate structure) was inferred from reduced numbers of pores and voids, alterations in colouring (an indication that iron has changed oxidation state) and increased bulk density (up to 30 %). Eleven years of irrigation changed the soil from a Calcic Palexeralf (non-irrigated) to an Aquic Natrixeralf (irrigated) (Soil Survey Staff, 1999). These results, combined with data from Chapter 4, were used to develop a mechanistic model of soil changes with irrigation. Chapters 6, 7 and 8 describe field experiments conducted in the Barossa Valley and McLaren Vale regions. This data shows seasonal and spatial variations in soil saturation extract properties ( EC [subscript se], SAR [subscript se], Na [subscipt se] and Ca [subscript se] ). At the Barossa Valley site (Chapter 6) non-irrigated soils had low EC [subscript se], SAR [subscript se], Na [subscript se] and Ca [subscript se] values throughout the sampling period. The irrigated treatments included eleven years of drip irrigation with saline water (2.5 dS / m) and also gypsum application at 0, 4 or 8 tonnes/hectare in 2001 and 2002. Salts in the profile increased with gypsum application rate, with high levels occurring midwinter 2002 prior to rainfall leaching salts. SAR has declined with gypsum application, particularly in the A horizon and at 100 cm from the dripper in the Bt1 horizon ; this has the potential to reflocculate clay particles and improve soil hydraulic conductivity. Chapter 7 presents further results from the Barossa Valley site, this treatment had been irrigated for 9 years with saline water (2.5 dS / m) prior to switching to a less saline water source (0.5 dS / m). The soil also received gypsum at 0, 4 or 8 tonnes / hectare in 2001 and 2002. It was found that the first few years are critical when switching to a less saline water source. EC declines rapidly, but SAR requires a number of years, depending on conditions, to decline, resulting in a period during which the Bt1 horizon may become dispersed. Gypsum application increased the EC [subscipt se] but not to the EC [subscript se] levels of soil irrigated with saline water. Chapter 8 examines soil chemical properties of a McLaren Vale vineyard, irrigated with moderately saline water (1.2 dS / m) since 1987 and treated with gypsum every second year since establishment. This practice prevented the SAR (< 8) rising and a large zone of the soil profile (20 to 100 cm from dripper) has a high calcium level (> 5 mmol / L). However, irrigation caused the leaching of calcium beneath the dripper in both the A and B horizons (0 to 20 cm from dripper) (< 4 mmol / L). Chapters 9 and 10 interpret and discuss results from continuous monitoring of redox potential (Eh) and soil solution composition in the Barossa Valley vineyard, irrigated with saline or non-saline water, and gypsum-treated at 0 and 4 tonnes / hectare. Soil pore water solution (Chapter 9) collected by suction cups is compared to results obtained in chapters 6 and 7. The soil has extended zones and times of high SAR and low EC. This was particularly evident in the upper B horizon, where the SAR of the soil remained stable throughout the year while the EC was more seasonally variable with EC declining during the winter months. The A horizon does not appear to be as susceptible to clay dispersion (compared to the B horizon) because during periods of low EC the SAR also declines, which may be due to the low CEC (low clay and organic matter content) of this horizon. Chapter 10 presents redox potentials (Eh) measured using platinum redox electrodes installed in the A, A2 and Bt1 horizons to examine whether Eh of the profile varies with irrigation water quality and gypsum application. Saline irrigation water caused the B horizon to become waterlogged in winter months, while less saline irrigation water caused a perched watertable to develop, due to a dispersed Bt1 horizon. Application of gypsum reduced the soil Eh particularly in the A2 horizon (+ 500 to + 50 mV) during winter. Thus redox potential can be influenced by irrigation water quality and gypsum applications. Chapter 11 incorporated site data from the Barossa Valley non-irrigated site into a predictive mathematical model, TRANSMIT, a 2D version of LEACHM. This model was used to predict zones of gypsum accumulation during long-term irrigation (67 years). When applied over the entire soil surface, gypsum accumulated at 60 to 90 cm from the dripper in the B horizon; higher application rates caused increased accumulation. When applied immediately beneath the irrigation dripper, gypsum accumulated in a 'column' under the dripper (at 0 to 35 cm radius from the dripper), with very little movement away from the dripper. Also, the zone of accumulation of salts from high and low salinity irrigation water was investigated. These regions were found to be similar, although concentrations were significantly lower with low salinity water. In low rainfall years salts accumulated throughout the B horizon (35 - 150 cm), while in periods of high rainfall (and leaching) the A, A2 and Bt1 horizons (0 - 60 cm) were leached, although at greater depths (80 - 150 cm) salt concentrations remained high. Chapter 12 summarises results and provides an understanding of soil processes in drip irrigated soils to underpin improved management options for viticulture. This study combines results from redox and soil solution monitoring, mineralogy, elemental gains and losses, and seasonal soil sampling to develop a mechanistic model of soil processes, which was combined with computer modelling to predict future properties of the soil. Major conclusions and recommendations of this study include : - Application of saline irrigation water to soil then ameliorated with gypsum - The first application of gypsum was leached by the subsequent irrigation from extended regions of the soil. As Na continues to enter the system via irrigation water, gypsum needs to be regularly applied. Otherwise calcium will be leached through the soil and SAR increases. - Application of non-saline irrigation water to soil then ameliorated with gypsum - The soil was found to only require one application at 8 tons / ha as this reduced SAR sufficiently. As less salt is entering the soil, subsequent gypsum applications can be at a lower rate or less frequently than required for saline irrigation water. - Gypsum applied directly beneath the dripper systems distributes calcium to a narrow region of the soil, while large regions of the soil require amelioration (high SAR) and are not receiving calcium. Therefore, gypsum application through the drip system or only beneath the dripper should be combined with broad acre application. - A range of methods to sample vineyards is recommended for duplex soils, including the use of saturation extracts, sampling time, sampling location (distance from dripper) and depth of sampling. This work is critical for vineyard management and may be applicable to other Australian viticulture regions with Red Brown Earths. / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2004.

Irrigation water of poor quality can have deleterious effects on soils. However, the effect of drip irrigation on seasonal and long term (e.g. over 50 years) changes in soil chemical properties is poorly understood, complicated by the two-dimensional water flow patterns beneath drippers. Field and laboratory experiments were conducted, along with computer modelling, to evaluate morphological and physio-chemical changes in a typical Barossa Valley Red Brown Earth (Palexeralf, Chromosol or Lixisol) when drip irrigated under various changing management practices. This work focused on the following two management changes : (i) switching from long-term irrigation with a saline source to less saline water and (ii) gypsum (CaSO₄) application. A literature review (Chapter 1) focuses on the distribution, features, properties and management of Red Brown Earths in the premium viticultural regions of the Barossa Valley and McLaren Vale, South Australia. The effects of irrigation method and water quality on the rate and extent of soil deterioration are emphasised. The review also discusses the irrigation of grapes (Vitis vinifera) and summarises previous research into the effect of sodicity and salinity on grape and wine characteristics. This chapter shows the importance of Red Brown Earths to Australian viticulture, but highlights their susceptibility to chemical and physical degradation. Degradation may be prevented or remediated by increasing organic matter levels, applying gypsum, modifying cropping and through tillage practices such as deep ripping. Chapter 2 provides general information on the two study sites investigated, one in the Barossa Valley and the other at McLaren Vale. Local climate, geology, geomorphology and soils are described. Chapter 3 details laboratory, field and sampling methods used to elucidate changes in soil chemical and physical properties following irrigation. The genesis of the non-irrigated Red Brown Earth in the Barossa Valley is described in Chapter 4, and is inferred from geochemical, soil chemical, layer silicate and carbonate mineralogical data. Elemental gain and loss calculations showed 42% of original parent material mass was lost during the formation of A and A2 horizons, while the Bt1 and Bt2 horizons gained 50% of original parent material mass. This is consistent with substrate weathering and illuviation of clay from surface to lower horizons. The depth distributions of all major elements were similar ; the A horizon contained lower amounts of major elements than the remainder of the profile, indicating this region was intensely weathered. This chapter also compares the non-irrigated site to the adjacent irrigated site (separated by 10 m) to determine if the sites are pedogenically identical and geochemical changes from irrigation. Many of the differences between the non-irrigated and irrigated sites appear to be correlated with variations in quartz, clay, Fe oxide and carbonate contents, with little geological variation between the sample sites. In Chapter 5 morphological, chemical and physical properties of a non-irrigated and irrigated Red Brown Earth in the Barossa Valley are compared. Alternating applications of saline irrigation water (in summer) and non-saline rain water (in winter) have caused an increase in electrical conductivity (EC [subscript se]), sodium adsorption ratio (SAR), bulk density (ρ b) and pH. This has resulted in enhanced clay dispersion and migration. Impacts on SAR and ρ b are more pronounced at points away from the dripper due to the presence of an argillic horizon, which has greatly influenced the variations in these soil properties with depth and distance from the dripper. Dispersion and migration of clay were promoted by alternating levels of EC, while SAR remained relatively constant, resulting in the formation of a less permeable layer in the Bt1 horizon. Clay dispersion (breakdown of micro-aggregate structure) was inferred from reduced numbers of pores and voids, alterations in colouring (an indication that iron has changed oxidation state) and increased bulk density (up to 30 %). Eleven years of irrigation changed the soil from a Calcic Palexeralf (non-irrigated) to an Aquic Natrixeralf (irrigated) (Soil Survey Staff, 1999). These results, combined with data from Chapter 4, were used to develop a mechanistic model of soil changes with irrigation. Chapters 6, 7 and 8 describe field experiments conducted in the Barossa Valley and McLaren Vale regions. This data shows seasonal and spatial variations in soil saturation extract properties ( EC [subscript se], SAR [subscript se], Na [subscipt se] and Ca [subscript se] ). At the Barossa Valley site (Chapter 6) non-irrigated soils had low EC [subscript se], SAR [subscript se], Na [subscript se] and Ca [subscript se] values throughout the sampling period. The irrigated treatments included eleven years of drip irrigation with saline water (2.5 dS / m) and also gypsum application at 0, 4 or 8 tonnes/hectare in 2001 and 2002. Salts in the profile increased with gypsum application rate, with high levels occurring midwinter 2002 prior to rainfall leaching salts. SAR has declined with gypsum application, particularly in the A horizon and at 100 cm from the dripper in the Bt1 horizon ; this has the potential to reflocculate clay particles and improve soil hydraulic conductivity. Chapter 7 presents further results from the Barossa Valley site, this treatment had been irrigated for 9 years with saline water (2.5 dS / m) prior to switching to a less saline water source (0.5 dS / m). The soil also received gypsum at 0, 4 or 8 tonnes / hectare in 2001 and 2002. It was found that the first few years are critical when switching to a less saline water source. EC declines rapidly, but SAR requires a number of years, depending on conditions, to decline, resulting in a period during which the Bt1 horizon may become dispersed. Gypsum application increased the EC [subscipt se] but not to the EC [subscript se] levels of soil irrigated with saline water. Chapter 8 examines soil chemical properties of a McLaren Vale vineyard, irrigated with moderately saline water (1.2 dS / m) since 1987 and treated with gypsum every second year since establishment. This practice prevented the SAR (< 8) rising and a large zone of the soil profile (20 to 100 cm from dripper) has a high calcium level (> 5 mmol / L). However, irrigation caused the leaching of calcium beneath the dripper in both the A and B horizons (0 to 20 cm from dripper) (< 4 mmol / L). Chapters 9 and 10 interpret and discuss results from continuous monitoring of redox potential (Eh) and soil solution composition in the Barossa Valley vineyard, irrigated with saline or non-saline water, and gypsum-treated at 0 and 4 tonnes / hectare. Soil pore water solution (Chapter 9) collected by suction cups is compared to results obtained in chapters 6 and 7. The soil has extended zones and times of high SAR and low EC. This was particularly evident in the upper B horizon, where the SAR of the soil remained stable throughout the year while the EC was more seasonally variable with EC declining during the winter months. The A horizon does not appear to be as susceptible to clay dispersion (compared to the B horizon) because during periods of low EC the SAR also declines, which may be due to the low CEC (low clay and organic matter content) of this horizon. Chapter 10 presents redox potentials (Eh) measured using platinum redox electrodes installed in the A, A2 and Bt1 horizons to examine whether Eh of the profile varies with irrigation water quality and gypsum application. Saline irrigation water caused the B horizon to become waterlogged in winter months, while less saline irrigation water caused a perched watertable to develop, due to a dispersed Bt1 horizon. Application of gypsum reduced the soil Eh particularly in the A2 horizon (+ 500 to + 50 mV) during winter. Thus redox potential can be influenced by irrigation water quality and gypsum applications. Chapter 11 incorporated site data from the Barossa Valley non-irrigated site into a predictive mathematical model, TRANSMIT, a 2D version of LEACHM. This model was used to predict zones of gypsum accumulation during long-term irrigation (67 years). When applied over the entire soil surface, gypsum accumulated at 60 to 90 cm from the dripper in the B horizon; higher application rates caused increased accumulation. When applied immediately beneath the irrigation dripper, gypsum accumulated in a 'column' under the dripper (at 0 to 35 cm radius from the dripper), with very little movement away from the dripper. Also, the zone of accumulation of salts from high and low salinity irrigation water was investigated. These regions were found to be similar, although concentrations were significantly lower with low salinity water. In low rainfall years salts accumulated throughout the B horizon (35 - 150 cm), while in periods of high rainfall (and leaching) the A, A2 and Bt1 horizons (0 - 60 cm) were leached, although at greater depths (80 - 150 cm) salt concentrations remained high. Chapter 12 summarises results and provides an understanding of soil processes in drip irrigated soils to underpin improved management options for viticulture. This study combines results from redox and soil solution monitoring, mineralogy, elemental gains and losses, and seasonal soil sampling to develop a mechanistic model of soil processes, which was combined with computer modelling to predict future properties of the soil. Major conclusions and recommendations of this study include : - Application of saline irrigation water to soil then ameliorated with gypsum - The first application of gypsum was leached by the subsequent irrigation from extended regions of the soil. As Na continues to enter the system via irrigation water, gypsum needs to be regularly applied. Otherwise calcium will be leached through the soil and SAR increases. - Application of non-saline irrigation water to soil then ameliorated with gypsum - The soil was found to only require one application at 8 tons / ha as this reduced SAR sufficiently. As less salt is entering the soil, subsequent gypsum applications can be at a lower rate or less frequently than required for saline irrigation water. - Gypsum applied directly beneath the dripper systems distributes calcium to a narrow region of the soil, while large regions of the soil require amelioration (high SAR) and are not receiving calcium. Therefore, gypsum application through the drip system or only beneath the dripper should be combined with broad acre application. - A range of methods to sample vineyards is recommended for duplex soils, including the use of saturation extracts, sampling time, sampling location (distance from dripper) and depth of sampling. This work is critical for vineyard management and may be applicable to other Australian viticulture regions with Red Brown Earths. / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2004.

Identifying a genetic basis for the tolerance to salinity exhibited by the resilient moss, Physcomitrella patens, could provide valuable information for use in the selection or modification of salinity tolerance in crop plants. The overall aim of the work described in this thesis was to identify, express and functionally characterise the protein products of two putative salinity tolerance genes from Physcomitrella, namely PpMdhar and PpENA1. The characterisation of PpMdhar and PpENA1 represents a two-pronged approach into investigating the salinity tolerance of Physcomitrella at the biochemical and transport level, respectively. The enzymes encoded by PpMdhars, monodehydroascorbate reductases (MDHARs), are central to the ascorbate-glutathione cycle, and recycle monodehydroascorbate molecules into the antioxidant, ascorbate. Hence, MDHARs play a part in maintaining the capacity of plant cells to remove toxic reactive oxygen species. Given that the production of reactive oxygen species is greatly increased in plants under salt stress, and that Physcomitrella is tolerant of high salt, MDHAR enzymes were expressed to determine whether they exhibit increased enzymic activity when compared with MDHARs from higher plants. The protein encoded by PpENA1 is Na⁺ transporting ATPase, which actively transports toxic Na⁺ ions across the cell membranes, and thereby minimizes the level of Na⁺ that accumulates in the cytoplasm. Thus, in contrast to the mechanism by which MDHARs may help Physcomitrella deal with the secondary effects of high salt, the PpENA1 protein could enable the moss to actively exclude Na⁺ ions, and thereby avoid cellular toxicity. A link between salinity and the transcription of PpMdhar and PpENA1 is reported here, and the function of each gene is investigated. A comprehensive characterisation of the enzymic action of expressed PpMDHAR enzymes is described, demonstrating that the biochemical mechanisms used by Physcomitrella in dealing with salt-induced reactive oxygen species are likely to be conserved with vascular plants. The physiological effects of the expression of PpENA1 are investigated via complementation experiments in yeast, and the membrane location of the protein is determined. The Na⁺ binding-sites of PpENA1 are predicted using homology modelling and amino acid residues crucial for Na⁺ transport are tested experimentally via site-directed mutagenesis. Finally, the introduction of a new, functional Na⁺ binding-site into an inactivated form of the PpENA1 protein demonstrates that a degree of control is possible over the Na⁺ binding-sites in PpENA1. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337385 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2008

Sustainability responds to crises of ecology and human development and the relationships between them. Sustainability cannot be adequately described using disciplinary categories arising from the modern dichotomy between nature and culture. Sustainability research requires a methodology that reflects the reality of its subject. This thesis presents material semiotics as a methodology for sustainability research. Material semiotics refers to the work of actor-network theorists and latter developments of alternate spatial metaphors for material relationality. Actor-network theory is a methodology that describes human and non-human actors in the same terms. It follows actor through networks of material relationships that they constitute and are constituted by, depicting heterogeneous objects without recourse to prior categories of nature or culture. The description of material relationships in fluid and regional, as well as network, spaces expands the descriptive power of material semiotics to include Others and to better represent complexity. The Oil Mallee Project is a case study of sustainability in the Western Australian wheatbelt. Indigenous eucalypts, oil mallees, are planted on land that was cleared for agriculture. The above ground biomass can be processed for eucalyptus oil, electricity and activated carbon, and the rights to carbon stored in the extensive mallee roots, or in unharvested trees, can be sold. The Project responds to a number of sustainability issues, including ozone depletion, land degradation, climate change and rural decline. This thesis follows the actors that comprise the Oil Mallee Project to describe its complexity, multiplicity and sustainability. Qualitative interviews with actors in the Project and the wheatbelt provided the primary data, which is supported by documentary material. Three contingent phases can be identified in the history of the Oil Mallee Project – eucalyptus oil industry, dryland salinity management, and greenhouse response. The Project has persisted because it is simultaneously a regional, network and fluid object. Mallees grow well in the tough conditions of the wheatbelt. Mallees can be integrated with existing networks of industrial agriculture. The Project has achieved contingent stability in policy documents and the networks of scientific research. The fluidity of the Project has enabled it to change shape and identity in response to threats and opportunities, and as relationships break and form, without complete disruption. Specific humans have been central heroes in different phases of the Project. The mallees themselves are the only actors that have been consistently central to the identity of the Project. Sustainability requires knowledge of the relationships between humans and non-humans that constitute the multiple crises of ecology and human development. Sustainability is the re-ordering of those relationships in ways that make possible ecological integrity and human fulfilment. Material semiotics is a methodology for knowing sustainability in ways that reveal the possibilities for such re-orderings.

Secondary salinisation has affected large areas of inland southwestern Australia, and in particular, low lying aquatic areas; causing the loss of freshwater submerged macrophyte communities and their replacement by salt-tolerant species. At high salinities, the salt-tolerant macrophyte-dominated ecological regime may be replaced by a regime dominated by benthic microbial communities, further reducing the structural and functional diversity of salinised wetland ecosystems. There is little prospect of restoring salinised systems to a freshwater state, meaning that saline macrophyte dominated wetlands have a heightened structural and functional importance in this landscape. Prior to this study, little was known about the drivers for change from one ecological regime to another in salinising wetlands or about rates of ecosystem response to these drivers. This study used experimental and observational data from seven saline wetlands in order to identify some of the potential mechanisms for the transition between the salt tolerant submerged macrophyte-dominated regime and the benthic microbial community-dominated regime. The applicability of existing conceptual models for ecological regime shifts was then tested against these data. Some of the mechanisms responsible for the formation and maintenance of the macrophyte-dominated regime were explored by examining the effects of salinity on germination and flowering in a series of salt-tolerant submerged macrophytes. The initiation and dominance of benthic microbial communities over a range of salinity and wetting regimes was also examined. The results suggested that macrophyte communities are unlikely to develop in seasonally-drying wetlands at high salinities (>45 ppt), but will usually germinate and establish well at lower salinities. It was also predicted that although benthic microbial communities can survive and grow across a wide range of salinities, they are likely to be outcompeted at low salinities by macrophytes or by phytoplankton blooms if water column nutrient levels are high. However, water permanence may facilitate benthic microbial community dominance. Existing conceptual models of ecological regime transitions, such as the alternative regimes model, did not account for the effect of water regime on the dynamics of seasonally-drying systems. Therefore, a new conceptual model incorporating the interaction between hydrology and salinity in seasonally-drying wetlands was proposed.

Thesis (M.S.)--University of North Carolina Wilmington, 2008. / Title from PDF title page (viewed May 27, 2009) Includes bibliographical references (p. 56-61)

Mémoire (M. Sc. A.)-- Université du Québec à Chicoutimi, 1984. / Bibliographie: f. 77-81. Document électronique également accessible en format PDF. CaQCU

Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 96-101). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D)--Université de Paris, Faculté des Sciences, 1970. / Includes bibliographical references (leaves [1-8] (at end)).

Thesis (Ph. D.)--Oregon State University, 1972. / Includes bibliographical references (leaves 104-107).