This thesis is concerned with the role of submergence in the ecology of the perennial Ranunculus repens and the annual R. sceleratus, both of which are common in seasonally submerged habitats. Evidence is presented for genetic differentiation between R. repens populations with respect to tactical changes in allocation and growth form in response to submergence. R. repens plants maintain or increase their dry weight allocation to stolons in response to submergence independent of site of origin. A decrease in flowering in submerged R. repens plants was related to a change in the positive correlation between total dry weight and the probability of flowering in these plants. The dry weight per unit length of petioles decreased in response to submergence in plants from all sites but changes in the dry weight per unit length of stolons depended on the site of origin of the plants. Plants from all sites showed plasticity in growth form with respect to stolon internode lengths but the direction of change in response to submergence depended on site. At low nutrient levels R. sceleratus plants showed increased dry weight allocation to vegetative organs in response to submergence but unchanged or reduced allocation to sexual reproductive structures. However, all changes in allocation in response to submergence disappeared at higher nutrient levels. Reductions in the number of flowers per plant in response to submergence were independent of nutrient status but plants at high nutrient levels showed no change in the number of seeds per plant due to a larger number of seeds per seed head. This may be related to the association of this species with nutrient rich habitats. A demographic analysis of R. sceleratus showed that these plants can exhibit a wide range of life history tactics. There was a trend for a longer pre-flowering period to result in lower survivorship but greater seed output. Seed germination in this species is promoted by diurnally fluctuating temperatures in both the light and dark but the promotion is greatest in the former.

South Louisiana regularly experiences effects from flooding. This study looks at what homeowners are doing to reduce their losses from floods through the practices of flood mitigation. I developed four hypotheses to predict homeowners' mitigation behavior. (1) Homeowners with a history of flooding are likely to mitigate more than those without previous flooding. (2) High-disposable-income homeowners are more likely to mitigate than lowdisposable- income homeowners. (3) The stronger the place attachment among homeowners, the higher the likelihood they will mitigate. (4) Homeowners who have experienced effective mitigation measures in the past are more likely to mitigate than those who have not. To test these hypotheses, a survey was administered in five different neighborhoods throughout Orleans and Jefferson parishes having high concentrations of repeatedly flooded homes. The findings suggest severity of past flooding, disposable savings, strong relationships with neighbors, and discussion of flooding with neighbors are the strongest predictors of flood mitigation.

A boreal forest wetland (L979) was flooded in 1993 at the Experimental Lakes Area, Ontario to imitate a hydroelectric reservoir and to study the effects of flooding on greenhouse gas production and emission. Flooding initially caused CO₂ and CH4 emission rates to increase and changed the wetland from a small, natural carbon sink to a large source of carbon. The increased production of greenhouse gases in the peatland also caused the majority of the peat to float to the surface creating floating peat islands, within 4 years of flooding. The floating peat islands are a larger source than the central pond of CH4 to the atmosphere due to the high water table and small oxidation zone as compared to the earlier undisturbed peatland. The floating peat islands had an average flux of 202 ± 66 mg C-CH4/m²/day comparable to rates measured in 1995. Methane flux rates are spatially and temporally variable ranging from ?117 to 3430 mg C-CH4/m²/day. The variability is partly due to episodic releases of gas bubbles and changes in overlying pressure from the water table. The development of floating peat islands created an underlying water pocket. The water pocket increased water movement between the central pond and the peatland and led to increased peat temperatures and methane oxidation, and removal of debris from the water pocket. DIC, CH4, and O₂ concentrations, and δ13C-DIC, δ13-CH4, and δ18O-O₂ values in the water pocket were similar to values in the central pond. Before flooding, the δ13C-CH4 values from the peatland ranged between ?36 and ?72? indicating that about 65 to 90% of the methane was oxidized before flooding. After flooding, the median δ13C-CH4 value from the floating peat islands was ?52? indicating that about 30% of the methane was oxidized before it was emitted to the atmosphere. Since the floating islands are now vegetated, photosynthesis and transport via plants allow the movement of oxygen into the peat islands Methane oxidation in the central pond was similar in 2001 and 2002. DIC and CH4 isotope mass budgets from June 3 to September 23, 2002 indicate that inputs were smaller than outputs at L979. Calculated net DIC and CH4 production in the central pond was 8490 and 432 kg C, with δ13C-DIC of -18. 5 ? and δ13C-CH4 of -32. 5?. Decomposition of peat was the source of DIC and CH4. O₂ saturation levels indicate that the pond is always undersaturated and that respiration dominates the system; however, the δ18O-O₂ also indicates that photosynthesis is an important process in the central pond of L979. The peat islands contributed about 90% of the total CH4 flux, whereas the open water areas contributed 10%. This indicates that formation of peat islands in a hydroelectric area can significantly affect the greenhouse gas emissions to the atmosphere. The average flux of CH4 from the entire wetland in 2002 was 202 ± 77 mg C-CH4/m²/day, equivalent to 44 ± 17 g C-CH4/m²/year (year = 220 days). This is higher than preflood values of 0. 5 g C-CH4/m²/year in 1992, and the early post-flood value of 8. 9 g C-CH4/m²/year in 1993/1994. The wetland continues to emit methane after ten years of flooding at higher than preflood rates.

A boreal forest wetland (L979) was flooded in 1993 at the Experimental Lakes Area, Ontario to imitate a hydroelectric reservoir and to study the effects of flooding on greenhouse gas production and emission. Flooding initially caused CO₂ and CH4 emission rates to increase and changed the wetland from a small, natural carbon sink to a large source of carbon. The increased production of greenhouse gases in the peatland also caused the majority of the peat to float to the surface creating floating peat islands, within 4 years of flooding. The floating peat islands are a larger source than the central pond of CH4 to the atmosphere due to the high water table and small oxidation zone as compared to the earlier undisturbed peatland. The floating peat islands had an average flux of 202 ± 66 mg C-CH4/m²/day comparable to rates measured in 1995. Methane flux rates are spatially and temporally variable ranging from ?117 to 3430 mg C-CH4/m²/day. The variability is partly due to episodic releases of gas bubbles and changes in overlying pressure from the water table. The development of floating peat islands created an underlying water pocket. The water pocket increased water movement between the central pond and the peatland and led to increased peat temperatures and methane oxidation, and removal of debris from the water pocket. DIC, CH4, and O₂ concentrations, and δ13C-DIC, δ13-CH4, and δ18O-O₂ values in the water pocket were similar to values in the central pond. Before flooding, the δ13C-CH4 values from the peatland ranged between ?36 and ?72? indicating that about 65 to 90% of the methane was oxidized before flooding. After flooding, the median δ13C-CH4 value from the floating peat islands was ?52? indicating that about 30% of the methane was oxidized before it was emitted to the atmosphere. Since the floating islands are now vegetated, photosynthesis and transport via plants allow the movement of oxygen into the peat islands Methane oxidation in the central pond was similar in 2001 and 2002. DIC and CH4 isotope mass budgets from June 3 to September 23, 2002 indicate that inputs were smaller than outputs at L979. Calculated net DIC and CH4 production in the central pond was 8490 and 432 kg C, with δ13C-DIC of -18. 5 ? and δ13C-CH4 of -32. 5?. Decomposition of peat was the source of DIC and CH4. O₂ saturation levels indicate that the pond is always undersaturated and that respiration dominates the system; however, the δ18O-O₂ also indicates that photosynthesis is an important process in the central pond of L979. The peat islands contributed about 90% of the total CH4 flux, whereas the open water areas contributed 10%. This indicates that formation of peat islands in a hydroelectric area can significantly affect the greenhouse gas emissions to the atmosphere. The average flux of CH4 from the entire wetland in 2002 was 202 ± 77 mg C-CH4/m²/day, equivalent to 44 ± 17 g C-CH4/m²/year (year = 220 days). This is higher than preflood values of 0. 5 g C-CH4/m²/year in 1992, and the early post-flood value of 8. 9 g C-CH4/m²/year in 1993/1994. The wetland continues to emit methane after ten years of flooding at higher than preflood rates.

Excess lubricant can be found as reservoirs on the sides of the rolling tracks when the oil flows through the Hertzian contact and the side leakage. Uniform lubricant layers adhered to both rolling surfaces can flow into the supply region by the action of surface tension. Uniform lubricant layers are separated by air so that they move with the surfaces the surface tension of the liquid-air interface and the velocity of the roller. Hence, it can be considered as the fixed flow rate conditions. Under the lubricant starvation and the fixed flow rate conditions, the meniscus in the film inlet is formed due to the action of the surface tension of the oil-air interface, where the fluid pressure in the oil layer is smaller than the ambient pressure. An empirical formula to predict the thickness of the oil layer is derived based on the theoretical analysis and the experimental results of Cann et al. [10]. Results show that this thickness increases the amount of oil in the track and the surface tension of the liquid-air interface, but it decreases with the surface velocity and the oil viscosity. Moreover, the starved, fully flooded, over-flooded regimes are established based on the theoretical analysis. Under the lubricant starvation and the fixed flow rate conditions, the central film thickness in the pressure region increases with increasing the supply flow rate, so that the location of the meniscus moves to upstream. When the supply flow rate is more than 98% flow rate of fully flooded condition, the central film thickness achieves a saturated value. Hence, when the supply flow rate is between 98% and 100% flow rate of fully flooded condition, it is called the fully flooded regime. When the supply flow rate is more than the flow rate of fully flooded condition, the central film thickness remains constant, and the excess oil accumulates in the inlet region, so that the film thickness in the inlet region increases with time. When the supply flow rate is larger than the flow rate of fully flooded condition, it is called the over-flooded region.

Cypress Creek is an under researched sub-watershed of the larger Cache River system located in Southern Illinois and is managed by the Cypress Creek National Wildlife Refuge (CCNWR). In 1996, the Cypress Creek Watershed and its encompassing wetlands were listed under the United Nations Education, Scientific, and Cultural Organization (UNESCO) and Ramsar as a “Wetland of International Importance”. These wetland habitats house unique aquatic woody species, such as the Bald Cypress and Water Tupelo, and have diminished in size due to agricultural priorities and changes in hydrology (Demissie et al. 1990; Illinois Department of Natural Resources 1997). Heitmeyer and Mangan (2012) conducted by the U.S. Fish and Wildlife Service (USFWS), assessed the Cypress Creek Watershed using historical references of pre-settlement topography and geomorphology and present-day soils to determine habitat potential. These variables alone do not address the needs of the aquatic woody species who require flood inundation to survive. This hydrologic and hydraulic assessment examines the present-day hydrologic conditions within the boundary limits of CCNWR by collecting channel geometry and stream discharges, building flow frequencies, and constructing a hydraulic model of Cypress Creek to simulate water surface elevations (WSELs) for the bankfull, 2-year, 5-year, 10-year, 20-year, and 25-year exceedance probabilities. Flood inundations were generated from simulated WSELs and local topography. The calculated potential habitat for Bald Cypress and Water Tupelo is 289 hectares and is located in the northwest part of the study area, south of Cypress Creek Road and above Hickory Bottoms Bridge on CCNWR land. Potential habitat overlap found between Heitmeyer and Mangan (2012) and this assessment is roughly 19 hectares.

Floods are natural phenomena which are a threat to human settlements. Flooding can result in costly repairs to buildings, loss of business and, in some cases, loss of life. The forecasts for climate change show a further increased risk of flooding in future years. Accordingly, the flooding of residential property has been observed as on the rise in the UK. It is difficult to prevent floods from occurring, but the effects of flooding can be managed in an attempt to reduce risks and costs of repair. This can be achieved through ensuring a good understanding of the problem, and thereby establishing good management systems which are capable of dealing with all aspects of the flood. The use of an intelligent system for assessment and remediation of buildings subjected to flooding damage can facilitate the management of this problem. Such a system can provide guidance for the assessment of vulnerability and the repair of flood damaged residential buildings; this could save time and money through the use of the advantages and benefits offered by knowledge base systems. A prototype knowledge base system has been developed in this research. The system comprises three subsystems: degree of vulnerability assessment subsystem; remediation options subsystem; and foundation damage assessment subsystem. The vulnerability assessment subsystem is used to calculate the degree of vulnerability, which will then be used by the remediation options subsystem to select remediation options strategy. The vulnerability assessment subsystem can subsequently be used to calculate the degree to which the building is vulnerable to damage by flooding even if it is not flooded. Remediation options subsystem recommended two strategy options: either ordinary remediation options in the case of vulnerability being low or, alternatively, resilience remediation options in the case of vulnerability being high. The foundation damage assessment subsystem is working alone and is used to assess the damage caused by flooding to the building s foundation, and to thereby recommend a repair option based on the damage caused and foundation type. The system has been developed based on the knowledge acquired from different sources and methods, including survey questionnaires, documents, interviews, and workshops. The system is then evaluated by experts and professionals in the industry. The developed system makes a contribution in the management and standardisation of residential building flooded damage and repair.

Dust is a detrimental, but unavoidable, consequence of any mining process. It is particularly problematic in underground coal mining, where respirable coal dust poses the potential health risk of coal workers’ pneumoconiosis (CWP). Float dust, if not adequately diluted with rock dust, also creates the potential for a dust explosion initiated by a methane ignition. Furthermore, recently promulgated dust regulations for lowering a miner’s exposure to respirable coal dust will soon call for dramatic improvements in dust suppression and capture. Computational fluid dynamics (CFD) results are presented for a research project with the primary goal of applying a flooded-bed dust scrubber, with high capture and cleaning efficiencies, to a Joy 7LS longwall shearer operating in a 7-ft (2.1 m) coal seam. CFD software, Cradle is used to analyze and evaluate airflow patterns and dust concentrations, under various arrangements and conditions, around the active mining zone of the shearer for maximizing the capture efficiency of the scrubber.

Darbas parengtas nustatant esamą situaciją užliejamose teritorijose. Tyrimo metu nustatyta, kad ūkininkauti tokiose vietose nėra lengva, nes yra taikomi apribojimai. Nustatyta, kad taikant šiuolaikines GIS technologijas būtų galima palengvinti ūkininkavimą, išskiriant vietas, kuriose palankiau ūkininkauti. Iškeltiems tyrimo uždaviniams pasiekti, buvo atlikta anketinė apklausa ir erdvinė duomenų analizė. Tyrimo tikslas – išanalizuoti Šilutės rajono užliejamų teritorijų ūkinio naudojimo tikslingumą ir numatyti perspektyvas. Tyrimo objektas – Šilutės rajono užliejamos teritorijos, išsamiau tirti trys vasaros polderiai: Uostadvario, Vorusnės, Pakalnės. Tyrimo uždaviniai: 1. Nustatyti esamą užliejamų teritorijų žemės naudojimą. 2. Aptarti duomenų, reikalingų erdvinei analizei atlikti, surinkimo ir naudojimo ypatumus. 3. Naudojant ArcGIS erdvinės duomenų analizės metodus, įvertinti žemės vertės variaciją erdvėje. 4. Įvertinti kaimo plėtros priemonių taikymą užliejamoms teritorijoms. Siekiant nustatyti Šilutės rajono užliejamų teritorijų ūkinio naudojimo tikslingumą ir perspektyvas buvo panaudoti šie metodai: anketinės apklausos, matematinės statistikos metodai, GIS duomenų erdvinė analizė. Tyrimas atliktas siekiant pademonstruoti, kaip šiuolaikinėmis GIS technologijomis galime daug tiksliau ir efektyviau įvertinti žemės vertės variaciją erdvėje bei žemės naudojimą. Polderiai išanalizuoti atliekant anketinę apklausą bei panaudojant ArcGIS 10.0 programą atlikta erdvinė duomenų... [toliau žr. visą tekstą] / The work was done by determining the current situation of flooded areas. During the research it was found that farming in such areas is not easy because of the restrictions. It was found that the application of modern GIS technology to facilitate farming, highlighting areas where favored. Raised by the study was carried out to achieve the objectives of a survey and analysis of spatial data. The goal of research is to analyze farm usage expediency and perspectives of flooded areas in Šilutės district. The object of survey is territories of flooded areas in Šilutės district, three summer polders were analyzed more comprehensively: Uostadvaris, Vorusnė, Pakalnė. Objectives of the survey: 1. To set the current land use of flooded areas. 2. To discuss the data necessary to perform spatial analysis, collection and usage. 3. To evaluate the variation of the value of land space using the ArcGIS Spatial data analysis methods. 4. Summarize applications measures of rural developments for flooded areas. The following methods: logical thinking, statistical clustering, comparison and analysis of GIS data were used to identify farm usage expediency and perspectives of flooded areas in Šilutės district. The research was completed to demonstrate how modern GIS technology can more accurately and efficiently assess the value of the land distribution and usage. Polders were analyzed via the questionnaire survey, also by use of ArcGIS 10.0 program accomplished a spatial analysis of the data... [to full text]

A exploração de petróleo em alto mar traz consigo desafios crescentes com o aumento da lâmina d’água e do grau de agressividade dos contaminantes presentes no fluido produzido. Sendo a produção no País majoritariamente escoada do poço para as unidades de produção por dutos flexíveis, faz-se necessária a realização de estudos aprofundados da influência destas condições na vida em fadiga destes equipamentos. Tais condições quando associadas ao alagamento da região anular dos dutos flexíveis, pode favorecer a corrosão das armaduras de tração, responsáveis por conferir resistência axial ao duto. Este fato compromete a integridade da estrutura, levando a operação à uma condição não segura. Com o intuito de elevar o grau de conhecimento sobre estes mecanismos de degradação, o presente estudo tem por objetivo estabelecer uma relação entre os parâmetros construtivos e operacionais destes dutos, com o seu desempenho em campo frente a carregamentos cíclicos e na condição de anular alagado Para tal, tendo como base a literatura disponível no tema, foram selecionados parâmetros de estudo para, a partir destes, determinar fatores de redução de vida em fadiga (FRVFs). Estes fatores foram quantificados e estudados através de correlações numéricas e experimentais, sendo validadas através da realização de um ensaio em escala real de um duto flexível com anular alagado com água do mar sintética saturada com dióxido de carbono. Como resultados foram obtidos fatores de redução de vida em fadiga para as condições estudadas. Ainda, foi estabelecida uma metodologia para a determinação destes e sua utilização para o cálculo do dano acumulado de fadiga nestes dutos. / Offshore oil exploration involves growing challenges as water depth increases and aggressive oil contaminants are present in production fluid. As Brazilian production is conducted from the well to the production units mostly through flexible pipes, studies regarding the influence of this conditions on fatigue life of these structures are necessary. When the annulus is flooded with seawater the above conditions turns the environment corrosive for tensile armor wires, that are responsible to provide axial strength to the pipe. This fact compromises the integrity of the structure as a whole turning the operation unsafe. To increase the knowledge regarding these degradation mechanisms this study aims to stablish a relationship between constructive and operational parameters with field performance considering dynamic loadings and flooded annulus conditions. For such, using the literature data available it was selected some relevant parameters and from these it was determined fatigue life reduction factors (FRVFs). The FRVF was quantified and studied using numeric and experimental relations and validated through a full scale fatigue test in flooded annulus condition with synthetic seawater saturated with CO2. As a result, it was obtained the FRFV to explored conditions. Even more, it was stablished a methodology for its determination and applicability for calculation of cumulative fatigue damage in flexible pipes.