The State of Florida ranks fifth in the world's production of phosphate. The phosphate industry relies on surface mining to withdraw the phosphate ore, and this process can devastate the natural environment. One of the most impacted natural resources is wetlands. Federal laws permit the legal destruction of wetlands providing their loss is compensated by the mitigation (i.e., the restoration, creation, or enhancement) of other wetlands, but the complexity of wetland ecosystems makes the mitigation process difficult. One of the goals of this thesis is to review the established Federal, State and non-regulatory guidelines for the development and maintenance of mitigated wetlands, evaluate their efficacy and present some underlying reasons for successful versus unsuccessful mitigation projects.The environmental repercussions of phosphate mining are not only pertinent to Florida or the United States. Wetland mitigation has become a global issue. Laws and programs that facilitate specific countries do not benefit wetland ecosystems on a landscape level. It is important to remain cognizant of the ramifications of wetland destruction and avoid piecemeal solutions to a wide-spread problem. Thus, my second objective is to investigate the progress and status of international wetland preservation. I will examine how different countries and international organizations are addressing the environmental impacts of mining, and underscore the relevant methods and protocols. I will also supplement this review by proposing the use of soil microbial communities as bioindicators of wetland development and sustainability. I will describe the laboratory and field procedures necessary to evaluate the various biological and physical aspects of mitigated wetlands, thereby offering mangers an effective monitoring technique. My intention is to confirm that microorganism development and preservation are critical to wetland health and longevity. My final objective is to document the relevant literature on environmental policy, and provide current scientific and policy review for researchers, managers and legislators. This thesis will synthesize the diverse and often contradictory theories, and suggest possible methodologies to bridge the science-policy gap.Overall, I intend to supply researchers, managers, and government agencies with a source of publications that can assist in evaluating, managing and monitoring wetland mitigation projects.

<p>Diss. (sammanfattning) Umeå : Umeå universitet, 1996, härtill 4 uppsatser</p> / digitalisering@umu

Issues affecting water quality are seen as one of the most important and pressing global problems of our era. In New Zealand, water bodies with the poorest water quality and ecological condition tend to be surrounded by pastoral land use. Lake Ellesmere/Te Waihora in Canterbury, New Zealand, is a typical example of the issues that nutrient and sediment run-off from pastoral land can create. The aim of this study was to determine the relationship between sediment concentrations, phosphate concentrations, ecological state and the degree of riparian restoration on drains that flowed into Lake Ellesmere/Te Waihora, and to calculate the load of phosphorus and sediment delivered by each of the drains to Te Waihora over the year, comparing this to the loads carried by larger, natural streams and rivers. Little research has been done on these small artificial tributaries of the Lake Ellesmere/Te Waihora catchment. Data collection was carried out on 10 drains with variable degrees of riparian planting, monthly in summer and autumn, and fortnightly in winter and spring, due to higher variability in drain flows during this time. Sites 1, 2 had low dissolved oxygen (DO) and high total phosphorus (TP), lack of flow and extremely high conductivity, and (with) Site 5, higher suspended particulate matter (SPM) concentrations. All these factors are consistent with the lack of ecology occurring in these drains. All drains failed to meet the Australian and New Zealand Environment and Conservation Council (ANZECC) guidelines for TP concentrations. All water chemistry parameters showed significant differences between seasons except conductivity. Mean water temperatures and pH were higher in summer and lower in winter, while mean DO levels were higher in winter (and spring) and lower in summer (and autumn). Macroinvertebrate analyses indicated moderate to severe pollution in all the drains, despite the amount of riparian planting present and the presence of macroinvertebrate community structure was related mainly to substrate size. The degree and type of riparian planting present on the drains studied did not appear to affect TP, SPM, macroinvertebrates or general water quality. This is likely to be due to the fact that little of the riparian planting had been specifically planted for restoration purposes. The highest loads of TP and SPM occurred in winter and spring, and in the larger (wider and deeper) drains. As flow increased in the drain, so did the load of phosphorus and sediment carried. Comparison with Environment Canterbury monitoring data for the river tributaries of the lake indicated that more TP and SPM is carried to the lake by natural rivers and streams, than by the drains, but the latter do make a significant contribution. The percentage of TP that is in dissolved form was higher than had previously been assumed, in both the drains and the larger, natural rivers and streams. It is recommended that future restoration work aim to reduce the amount of phosphorus and sediment entering the larger drains in winter and spring. More adequate riparian planting needs to occur on these drains, and it needs to be managed in a way that a reduction in dissolved phosphorus levels is also achieved.

The structure-property relationships of epoxy nanocomposites with inorganic layer-structure nanofillers have been studied to obtain the fundamental understanding of the role of nanofillers and the physics of polymer nanocomposites in this dissertation. Several polymer nanocomposite systems with modified montmorillonite (MMT) or α-zirconium phosphate (ZrP) nanofillers were prepared with epoxy matrices of different ductility and properties. The successful nanofiller's exfoliations were confirmed with X-ray diffraction and transmision electronic microscopy (TEM). Dynamic mechanical analysis (DMA) on the prepared epoxy nanocomposites revealed the significant increase in rubbery plateau moduli of the epoxy nanocomposite systems above Tg, as high as 4.5 times, and tensile test results showed improved modulus by the nanofiller addition, while the fracture toughenss was not affected or slightly decreased by nanofillers. The brittle epoxy nanocomposite systems were toughened with core shell rubber (CSR) particles and showed remarkable increase in fracture toughness (KIC) value up to 270%. The CSR toughening is more effective at ductile matrices, and TEM observation indicates that major toughening mechanisms induced by the CSR addition involve a large scale CSR cavitation, followed by massive shear deformation of the matrix.

At present, there are more than 2000 wastewater treatments plants (WWTPs) in Sweden. Emissions of nitrogen and phosphorus from these, do contribute to the eutrophication of the Baltic Sea and watercourses on a daily basis. To reduce emissions of phosphorus, the Swedish approach has for the last 50 years been to use chemical precipitation. Today, software is used to test and evaluate different strategies in WWTPs, this in order to improve the operation and get a holistic view over the process. One model that can be used to achieve a holistic view is the Benchmark Simulation Model No. 2 (BSM2). In order to get a software like BSM2 to best mirror the reality, it is important that the model well describes the actual process. Today, BSM2 does not take the load of phosphorus into account, which, if it was included in the model, would describe the process better. In this master thesis, the author has investigated the possibility of extending the BSM2 model, to include phosphorus and chemical precipitation. Thereafter the results from simulations in BSM2 were compared with measurements from Henriksdals WWTP in Stockholm. The results showed that a model, after some simplifications, for phosphorus and chemical precipitation could be included in BSM2. The model uses primary precipitation. Precipitation chemical was added with assistance of a PI controller. Generally the results showed that the model had potential to describe the total flow of phosphorus in the WWTP. In measurements from Henriksdal the average total phosphorus effluent from primary and secondary sedimentation were 3.97 and 0.43 mg/l, respectively. From a steady state simulation in BSM2 the values were ​​4.26 and 0.44 mg/l and the average values ​​of a dynamic simulation 3.96 and 0.46 mg/l. Although the average values of total phosphorus matches quite well, it was found difficult to simulate the different fractions of phosphorus effluent from the secondary sedimentation. In order to better evaluate the results and how the simplifications of the model affects them, more measurements need to be done and a comparison with the results received from the BSM2 needs to be carried out. Also an adjustment of parameters in BSM2 must be done, this to achieve a better compliance with the given plant. / Sverige har idag drygt 2000 reningsverk. Reningsverkens utsläpp av kväve och fosfor bidrar dagligen till övergödning i Östersjön och därtill anslutna vattendrag. För att minska utsläpp av fosfor har i Sverige sedan mitten på 1960-talet kemisk fällning använts. Idag används programvara för att testa och utvärdera olika strategier i reningsverken, detta med syftet att förbättra driften och få en helhetsbild över processen. En av dessa modeller är Benchmark Simulation Model No. 2 (BSM2). För att simuleringsprogram ska ge en så bra bild som möjligt av verkligheten är det viktigt att de beskriver processen, i detta fall avloppsvattenrening, på ett bra sätt. BSM2 tar i dagsläget inte hänsyn till belastningen av fosfor, om fosfor inkluderades i modellen skulle det beskriva processen bättre. I detta examensarbete, har författaren undersökt möjligheten att utvidga BSM2, till att inkludera fosfor och kemisk fällning i modellen. Resultaten erhållna från modellen har därefter jämförts med mätdata från Henriksdals reningsverk i Stockholm. Resultatet visade att en modell för fosfor och kemisk fällning kunde, efter vissa förenklingar, inkluderas i BSM2. I modellen användes förfällning och fällningskemikalier tillsattes med hjälp av en PI regulator. Generellt visade resultaten att modellen hade förmåga att beskriva det totala flödet av fosfor i reningsverket. I mätningarna från Henriksdal var medelvärdet på total fosfor ut från försedimenteringen 3,97 mg/l och från eftersedimenteringen 0,43 mg/l. Från en steady state simulering i BSM2 blev värdena 4,26 och 0,44 mg/l och medelvärdena från en dynamisk simulering 3,96 och 0,46 mg/l. Även om medelvärdena på totalfosfor stämmer relativt bra överens, fann man det svårt att simulera olika fraktioner av fosfor ut från eftersedimenteringen. För att bättre kunna bedöma resultatet och hur förenklingar i modellen påverkar resultatet behöver flera mätningar göras och jämföras med modellens resultat. En justering av parametrar i BSM2 måste även göras, detta för att anpassa modellen till det givna avloppsreningsverket bättre. / Development and dynamic analysis of operational strategies for enhanced energy efficiency of wastewater treatment systems

Anisotropy in glass can lead to a transmitted double image due to birefringence. Stress-induced birefringence, the stress-optic effect, is undesirable for applications such as commercial imaging. The leading zero stress-optic glass exhibits dispersive effects near its absorbance edge and thus cannot be used in broadband applications. Finding zero stress-optic glasses with minimal dispersive effects over a broad band of the visible region requires a theory to predict which combinations of glass formers and modifiers could exhibit minimal dispersion. Two glass families known to have a zero stress-optic response using white light, tin phosphates and tin silicates, were studied as a function of composition and wavelength. Near the absorbance edge, dispersion varied considerably with composition for tin phosphate glasses, but remained constant for tin silicate glasses. The significant factor is the oxygen bonding influence near the band edge. This leads to composition rules for synthesis of broadband, zero stress-optic glasses.

Abstract Plant cells contain plastids, organelles dedicated to performing specific biochemical processes including photosynthesis, starch and oil biosynthesis. Fatty acid biosynthesis in oil seeds occurs in one type of plastid termed the leucoplast. Anabolic metabolism in leucoplasts includes the production of fatty acids and amino acids that depend on the availability of reductants such as NADPH. NADPH can be generated in plastid by glucose 6-phosphate dehydrogenase (G6PDH) which is the chief control enzyme and first step in the Oxidative Pentose Phosphate Pathway (OPPP). G6PDH catalyses the reaction of NADP+ and glucose 6-phosphate to NADPH and 6-phosphogluconate. At least two compartment-specific isoforms of G6PDH exist in plants, a cytosolic and a plastidic form. In this study, castor oil seed (COS) (Ricinus communis L.) was used as a model enzyme system for the ongoing study of oil biosynthesis in plants. This is the first ever report of the full-length clone of the plastidic isoform of G6PDH being isolated from a castor cDNA library using polyclonal potato plastidic G6PDH antiserum. The full-length cDNA was sequenced and compared to other G6PDH genes from higher plants, the castor sequence reveals conserved regions and conserved cysteine residues similar to other higher plant G6PDH. Over expression of the recombinant cleaved fusion protein in an E. coli expression system from the isolation of the cDNA clone shows it is enzymatically active, stable and unlike other plastid G6PDH’s dithiothreitol insensitive. In fact this G6PDH shows increased activation in the presence of dithiothreitol. Initial kinetic characteristics shows that it behaves in a similar fashion enzymatically when compared to other higher plant chloroplast G6PDH. The gene sequence and initial kinetic findings for castor G6PDH concur with other higher plant, non-photosynthetic, plastidic isoforms. / Thesis (Master, Biology) -- Queen's University, 2007-09-19 13:41:54.584

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