This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

Thesis (M.S.)--Ohio University, March, 2008. / Title from PDF t.p. Includes bibliographical references.

Understanding the hydrological controls on subsurface flow and transport is of considerable importance in the study of reclaimed landscapes in the oil sands region of Canada. A significant portion of the reclaimed landscape will be comprised of a thin veneer (~ 1 m) of clay-rich reclamation soil overlying saline-sodic shale overburden, which is a waste by-product from the mining process. The global objective of this study was to investigate the first-order controls on soil moisture and salt transport dynamics within clay-rich reclamation covers overlying low permeability waste substrates. The study site is located in a cold, semi-arid climate in the oil sands region of northern Alberta. Preferential flow was the dominant mechanism responsible for the development of perched water table conditions on the cover-waste interface during the spring snow melt. Hydrological and geochemical data indicated that snowmelt infiltration occurs via the macroporosity while the ground is still frozen. An isotope hydrograph separation conducted on water collected in a weeping tile confirmed the presence of fresh snowmelt water at the onset of subsurface flow. This water transitions to a chemical signature that is comprised of approximately 80% connate pore water as a result of chemical equilibration between pore water in the soil matrix and fresh water in the macropores.<p>Detailed mapping of the spatial distribution of soil moisture and salts within a reclamation cover indicated the lower-slope positions are wetter due to the accumulation surface run-off and frozen ground infiltration in spring. Increased soil moisture conditions in lower-slope positions accelerate salt ingress, while drier conditions in middle and upper-slope positions attenuate salt ingress. The data indicated that fresh snowmelt water is bypassing the soil matrix higher in the cover profile. Subsurface flow and deep percolation are key mechanisms mitigating vertical salt ingress in lower and upper slope positions. The mesotopography of the cover-waste interface imposes a direct control on the depth of perched water and the downslope routing of water. Undulations in the cover-waste interface cause the depth of perched water to vary considerably (± 20 60 cm) over short distances (< 5 m), while saturated subsurface flow is routed through the lowest elevations in the cover profile. A numerical analysis of subsurface flow was able to simulate both the discharge rate and cumulative volume of flow to a weeping tile. Composite hydraulic functions were used in the simulations to account for the increased hydraulic conductivity and drainable porosity created by the macroporosity at near-saturated conditions. The transient Na+ concentration of discharge water was modelled using the concept of an equivalent porous medium. The good match between measured and modelled data verified the conceptual model, which contends that saturated subsurface flow is dominated by the fracture network and that the concentration of discharge water is function of the depth of perched water. Finally, the results from this study suggest the mesotopography of the cover-waste interface could be used to manage excess water and salts within the landscape.

Understanding the hydrological controls on subsurface flow and transport is of considerable importance in the study of reclaimed landscapes in the oil sands region of Canada. A significant portion of the reclaimed landscape will be comprised of a thin veneer (~ 1 m) of clay-rich reclamation soil overlying saline-sodic shale overburden, which is a waste by-product from the mining process. The global objective of this study was to investigate the first-order controls on soil moisture and salt transport dynamics within clay-rich reclamation covers overlying low permeability waste substrates. The study site is located in a cold, semi-arid climate in the oil sands region of northern Alberta. Preferential flow was the dominant mechanism responsible for the development of perched water table conditions on the cover-waste interface during the spring snow melt. Hydrological and geochemical data indicated that snowmelt infiltration occurs via the macroporosity while the ground is still frozen. An isotope hydrograph separation conducted on water collected in a weeping tile confirmed the presence of fresh snowmelt water at the onset of subsurface flow. This water transitions to a chemical signature that is comprised of approximately 80% connate pore water as a result of chemical equilibration between pore water in the soil matrix and fresh water in the macropores.<p>Detailed mapping of the spatial distribution of soil moisture and salts within a reclamation cover indicated the lower-slope positions are wetter due to the accumulation surface run-off and frozen ground infiltration in spring. Increased soil moisture conditions in lower-slope positions accelerate salt ingress, while drier conditions in middle and upper-slope positions attenuate salt ingress. The data indicated that fresh snowmelt water is bypassing the soil matrix higher in the cover profile. Subsurface flow and deep percolation are key mechanisms mitigating vertical salt ingress in lower and upper slope positions. The mesotopography of the cover-waste interface imposes a direct control on the depth of perched water and the downslope routing of water. Undulations in the cover-waste interface cause the depth of perched water to vary considerably (± 20 60 cm) over short distances (< 5 m), while saturated subsurface flow is routed through the lowest elevations in the cover profile. A numerical analysis of subsurface flow was able to simulate both the discharge rate and cumulative volume of flow to a weeping tile. Composite hydraulic functions were used in the simulations to account for the increased hydraulic conductivity and drainable porosity created by the macroporosity at near-saturated conditions. The transient Na+ concentration of discharge water was modelled using the concept of an equivalent porous medium. The good match between measured and modelled data verified the conceptual model, which contends that saturated subsurface flow is dominated by the fracture network and that the concentration of discharge water is function of the depth of perched water. Finally, the results from this study suggest the mesotopography of the cover-waste interface could be used to manage excess water and salts within the landscape.

No description available.

Thesis (Ph. D.)--University of Nevada, Reno, 2005. / "August, 2005." Includes bibliographical references. Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2005]. 1 microfilm reel ; 35 mm.

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / Chilling injury in banana fruit is caused by prolonged exposure to temperatures less than 13°C. This can occur during bunch development in the field or postharvest handling and storage. Mild symptoms of chilling injury are localised to peel tissue and reduce visual quality of fruit. Light microscopy was used in the present study to analyse symptoms of mild chilling injury in Cavendish cv. Williams banana. Following storage at 5°C for 24hours, symptoms of chilling injury in the form of brown discolouration was observed within laticifers in sub-epidermal peel tissue. Browning was not observed in other vascular tissues as previous research has suggested. Causal mechanisms associated with browning of latex within laticifers were investigated. Polyphenol oxidase (PPO) activity in fractions of banana peel latex was measured and found to be highest in the lutoid fraction. PPO activity also provided indirect evidence that phenolics were present in peel latex. Literature suggests possible compartmentalisation of PPO and phenolics in banana lutoids. In this study it is suggested that PPO and phenolics associated with lutoids in banana peel latex may be involved in browning due to chilling stress. The lipid content of lutoids from banana latex was also investigated using FTIR spectroscopy, but showed no further involvement of lutoids in the browning reaction caused by chilling. Control of field chilling using modified bunch covers was investigated. Bunch covers used in modern banana production are usually polyethylene bags, placed over bunches during development in the field. Experiments in a northern Queensland plantation investigated effects of modified bunch covers on fruit yield and quality characteristics of Cavendish cv. Williams bananas, including the development of mild chilling injury symptoms. A further field trial was conducted using different coloured bunch covers with varied interception of photosynthetically-active radiation (PAR), to determine any negative effects of bunch cover shading on fruit yield and quality. Different coloured and layered polyethylene films (blue, double green, silver yellow and silver black) modified PAR transmission of bunch covers (PAR transmission [%] = 56, 38, 7, 0). During summer 2003, varying PAR transmission of bunch covers significantly affected fruit size. Fruit from blue polyethylene covers, which transmitted most light, were larger than fruit from covers with less light transmission. Between cover treatments of lower light transmission, fruit size remained similar. It is suggested, during summer when cloud cover in northern Queensland limits solar radiation, bunch covers with high PAR transmission facilitate greater bunch photosynthesis, which improves fruit size. Fruit quality was generally unaffected by varying PAR transmission of bunch covers, but cover treatments were found to influence peel colour. Peel colour of fruit from 'silver black' covers was significantly paler. This may have impacted upon green life due to increased de-greening. Results from this experiment suggest that bunch photosynthesis significantly influences fruit size and peel colour during summer growing periods. Modified bunch covers constructed from existing bunch cover films and polyethylene bubble wrap ('blue + silver bubble' and sealed and non-sealed 'silver blue + silver bubble') were used to test control of field chilling during winter 2003 and 2004. Compared to standard blue polyethylene bunch covers, modified covers significantly reduced exposure of bunches to chilling conditions in the field and the development of visible chilling injury symptoms on the peel surface and in underpeel tissue. Greatest control of field chilling was shown using the non-sealed 'silver blue + silver bubble' cover design. Relative to the standard blue cover, in winter 2003 the non-sealed 'silver blue + silver bubble' cover design reduced chilling exposure by 95% at the top and 45% at the bottom of bunches. This totally controlled chilling injury symptoms in the top and middle bunch regions. In winter 2004 chilling conditions were more severe and chilling exposure was reduced by 85% using the non-sealed 'silver blue + silver bubble' cover. This reduced the severity of peel surface chilling symptoms by 67% in the top bunch region relative to fruit from blue covers. Yield characteristics were positively influenced by 'blue + silver bubble' and sealed and non-sealed 'silver blue + silver bubble' covers. Improved fruit size and weight was probably due to enhanced temperature conditions inside the bunch environment, relative to 'control' covers. Fruit quality was generally unaffected by 'blue + silver bubble' and sealed and non-sealed 'silver blue + silver bubble' covers. However peel colour was significantly influenced by these cover treatments, compared to the 'control' covers. Reduced light transmission of covers produced paler fruit. This may have influenced other quality characteristics, such as green life and SSC levels, as it confounded assessment of ripening stage. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1241852 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture and Wine, 2006

Thesis (M.S.)--California Polytechnic State University, 2009. / Mode of access: Internet. Title from PDF title page; viewed on July 17, 2009. Major professor: Dr. Faysal Kolkailah. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree of Master of Science in Aerospace Engineering." "June 2009." Includes bibliographical references (p. 284-287).

Absolutely pure modules act in ways similar to injective modules. Therefore, through-out this document we investigate many of these properties of absolutely pure modules which are modelled after those similar properties of injective modules. The results we develop can be broken into three categories: localizations, covers and derived functors. We form S1M, an S1R module, for any Rmodule M. We state and prove some known results about localizations. Using these known techniques and properties of localizations, we arrive at conditions on the ring R which make an absolutely pure S1Rmodule into an absolutely pure Rmodule. We then show that under certain conditions, if A is an absolutely pure Rmodule, then S1A will be an absolutely pure S1Rmodule. Also, we dene conditions on the ring R which guarantee that the class of absolutely pure modules will be covering. These include R being left coherent, which we show implies a number of other necessary properties. We also develop derived functors similar to Extn R (whose development uses injective modules). We call these functors Axtn R, prove they are well dened, and develop many of their properties. Then we dene natural maps between Axtn(M;N) and Extn(M;N) and discuss what conditions on M and N guarantee that these maps are isomorphisms.

No description available.