9 resultados para Didactic investigation

em Galway Mayo Institute of Technology, Ireland


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Sludge provides valuable nutrients to soil. Application of sludge to land is subject to a number of limitations. Its use as a soil conditioner represents a "beneficial reuse option". Primary and secondary sludge from Dublin city is treated in Ringsend treatment plant where it undergoes thermal drying. This study investigates the feasibility of land application of thermally dried biosolids (TDB) from Ringsend treatment plant.

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The aim of this study was to investigate the effects of biosurfactants and organic matter amendments on the bioremediation of diesel contaminated soil. Two strains of Pseudomonas aeruginosa with the ability to produce biosurfactant were isolated from a water and soil sample in Co. Sligo. The first strain, Isolate A, produced a biosurfactant which contained four rhamnose containing compounds, when grown in proteose peptone glucose ammonium salts medium with glucose as the carbon source. Two of the components were identified as rhamnolipid 1 and 2 whilst the other two components were unidentified. The second strain, Isolate GO, when grown in similar conditions produced a biosurfactant which contained only rhamnolipid 2. The type of aeration system used had a significant effect on the abiotic removal of diesel from soil. Forced aeration at a rate of 120L 02/kg soil/ hour resulted in the greatest removal. Over a 112 day incubation period this type o f aeration resulted in the removal o f 48% o f total hexane extractable material. In relation to bioremediation of the diesel contaminated sandy soil, amending the soil with two inorganic nutrients, KH2PO4 and NÜ4N03, significantly enhanced the removal of diesel, especially the «- alkanes, when compared to an unamended control. The biosurfactant from Isolate A and a biosurfactant produced by Pseudomonas aeruginosa NCIMB 8628 (a known biosurfactant producer), when applied at a concentration of three times their critical micelle concentration, had a neutral effect on the biodégradation o f diesel contaminated sandy soil, even in the presence o f inorganic nutrients. It was deduced that the main reason for this neutral effect was because they were both readily biodegraded by the indigenous microorganisms. The most significant removal of diesel occurred when the soils were amended with two organic materials plus the inorganic nutrients. Amendment of the diesel contaminated soil with spent brewery grain (SBG) removed significantly more diesel than amendment with dried molassed sugar beet pulp (DMSBP). After a 108 day incubation period, amendment of the diesel contaminated soil with DMSBP plus inorganic nutrients and SBG plus inorganic nutrients resulted in 72 and 89% removal of diesel range organics (DRO), in comparison to 41% removal of DRO in an inorganic nutrient amended control. The first order kinetic model described the degradation of the different diesel components with high correlation and was used to calculate Vi lives. The V2 life, of the total «-alkanes in the diesel was reduced from 40 days in the control to 8.5 and 5.1 days in the presence of DMSBP and SBG, respectively. The V2 life o f the unresolved complex mixture (UCM) in the diesel contaminated soil was also significantly reduced in the presence o f the two organics. DMSBP and SBG addition reduced UCM V2 life to 86 and 43 days, respectively, compared to 153 days in the control. The component of diesel whose removal was enhanced the greatest through the organic material amendments was the isoprenoid, pristane, a compound which until recently was thought to be nonbiodegradable and was used as an inert biomarker in oil degradation studies. The V2 life of pristane was reduced from 533 days in the nutrient amended control to 49.5 and 19.5 days in DMSBP and SBG amended soils. These results indicate that the addition o f the DMSBP and SBG to diesel contaminated soil stimulated diesel biodégradation, probably by enhancing the indigenous diesel degrading microbial population to degrade diesel hydrocarbons, whilst the addition o f biosurfactants had no enhanced effect on the bioremediation process.

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The purpose of this thesis is to answer the research question ‗why do some Polish migrants engage in shadow employment in the Republic of Ireland?‘ The individual and group interviews, which were conducted in August 2011 with thirteen Polish migrants, living and working in Ireland, generated the answer to the research question. Interviewees‘ responses were analysed from the point of view of the literature that examines the various factors within the topics of migration and the black economy. The thesis begins with theoretical background information regarding the enlargement of the European Union and the economic situation of Poland and Ireland. Then migration theories are explained and Polish and Irish migration history is presented. Next, the issue of the black economy and shadow employment is developed with a focus on its presence in Poland and Ireland. The following section is dedicated to the research methodology that was adopted to ensure effective collection of the information. The issues of the qualitative and quantitative research, phenomenological approach to the research and interviews as data collection are raised in that section. The last part of the thesis is based on an analysis of the respondents‘ statements. It explores interviewees‘ experience of life and work in Ireland. The main part of that section develops the reasons why do Polish workers engage in shadow employment in the Republic of Ireland. Simultaneously, it provides the answers to the research question of this thesis.

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Surgical procedures such as osteotomy and hip replacement involve the cutting of bone with the aid of various manual and powered cutting instruments including manual and powered bone saws. The basic mechanics of bone sawing processes are consistent with most other material sawing processes such as for wood or metal. Frictional rubbing between the blade of the saw and the bone results in the generation of localised heating of the cut bone. Research studies have been carried out which consider the design of the bone saw which deals with specifics of the saw teeth geometry and research which examines the effect of drilling operations on heating of the bone has shown that elevated temperatures will occur from frictional overheating. This overheating in localised areas is known to have an impact on the rate of healing of the bone post operation and the sharpness life of the blade. The purpose of this study was to measure the temperature at three zones at fixed intervals of 3mm, 6mm, and 9mm away from the cutting zone. It should be noted that it was the first time that this measurement technique was used to measure the temperature gradient through the bone specimen thereby establishing the extent to which clinicians are experiencing thermal injury during sawing of bone while using a reciprocating saw. The effect of various cutting feed rate on temperature elevation was also investigated in this research. The results showed that there will be a region of bone at least 9mm either side of the cutting blade experiencing thermal injury as temperatures in this region exceeded the threshold temperature of 44°C for necrosis (cell death).

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The focus of this research is in ascertaining how and why the Irish state patronises the visual arts. The framework that the state puts in place for the support of the arts influences the creation of art. The initial standpoint from which to evaluate the system is founded on the belief that art is of social good. The second source of belief is in the necessity for an autonomous setting in which it can be created. These two beliefs underpin state patronage of the arts in contemporary society. Therefore they have to be examined carefully in order to see if they hold up. This requires an investigation into the formation of value. This is undertaken by looking into the social development of western society and its influence on the placement of arts value. Establishing how arts value to society is defined provides a means by which to investigate the manner in which the state patronises the visual arts. Two case studies provide the evidence in how the state supports the arts and why it chooses to do so. The Irish Museum of Modem Art is used as an example of the state’s role in the maintenance of the canon of art. The second case study looks at the work being done by Breaking Ground. Breaking Ground is an extensive art project as an element of the regeneration process happening in Ballymun funded by the state. It provides and insight into how the state utilises art in the unification of a social group.

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Ireland’s remote position on the tip of Europe ensures that the country is vulnerable to uncertainty of supply. The reliance on conventional sources of electricity has ensured that escalated prices and high carbon emissions have been witnessed whilst opportunities that inherent resources provide, such as the wind, have not been capitalised upon. The intermittent nature of the wind make it difficult to maximise its potential as in many cases the highest wind speeds are highest when demand is low. The West of Ireland’s combination of wind speeds and unique topography makes it suitable for and innovative wind powered pumped storage system, which can essentially regulate the wind generated electricity and integrate further penetration of renewable energy. In addition, its location along the Atlantic Ocean provides further scope for innovation as seawater can be integrated into the system design. The construction of such an unprecedented project in combination with increased interconnectors has the potential to make Ireland a rechargeable battery for Europe. However, such ambitious plans are at the very early stages and are in direct contrast to current events in the Irish energy market. This study focuses on the feasibility of West of Ireland pumped storage systems. Entailed within this is an extensive desk study, a detailed site selection process and a feasibility study of grid connection. To increase opportunities to identify the best possible site, the feasibility study was focused on the Galway and Mayo areas solely.

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Although the ASP model has been around for over a decade, it has not achieved the expected high level of market uptake. This research project examines the past and present state of ASP adoption and identifies security as a primary factor influencing the uptake of the model. The early chapters of this document examine the ASP model and ASP security in particular. Specifically, the literature and technology review chapter analyses ASP literature, security technologies and best practices with respect to system security in general. Based on this investigation, a prototype to illustrate the range and types of technologies that encompass a security framework was developed and is described in detail. The latter chapters of this document evaluate the practical implementation of system security in an ASP environment. Finally, this document outlines the research outputs, including the conclusions drawn and recommendations with respect to system security in an ASP environment. The primary research output is the recommendation that by following best practices with respect to security, an ASP application can provide the same level of security one would expect from any other n-tier client-server application. In addition, a security evaluation matrix, which could be used to evaluate not only the security of ASP applications but the security of any n-tier application, was developed by the author. This thesis shows that perceptions with regard to fears of inadequate security of ASP solutions and solution data are misguided. Finally, based on the research conducted, the author recommends that ASP solutions should be developed and deployed on tried, tested and trusted infrastructure. Existing Application Programming Interfaces (APIs) should be used where possible and security best practices should be adhered to where feasible.

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Research was conducted to investigate the potential for ecologically engineering a sustainable wetland ecosystem over pyritic mine tailings to prevent the generation of acid mine drainage. Ecological engineering is technology with the primary goal being the creation of self-sustainable ecological systems. Work involved the design and construction of a pilot-scale wetland system comprising three wetland cells, each covering 100 m2. Approximately forty tonnes of pyritic mine tailings were deposited on the base of the first cell above a synthetic liner, covered with peat, flooded and planted with emergent wetland macrophytes Typha latifolia, Phragmites australis, and Juncus effusus. The second cell was constructed as a conventional free water surface wetland, planted identically, and used as a reference wetland/experimental control. Wetland monitoring to determine long-term sustainability focused on indicators of ecosystem health including ecological, hydrological, physico-chemical, geochemical, and biotic metrics. An integrated assessment was conducted that involved field ecology in addition to ecological risk assessment. The objective of the field ecology study was to use vegetative parameters as ecological indicators for documenting wetlands success or degradation. The goal of the risk assessment was to determine if heavy-metal contamination of the wetland sediments occurred through metal mobilisation from the underlying tailings, and to evaluate if subsequent water column chemistry and biotic metal concentrations were significantly correlated with adverse wetland ecosystem impacts. Data were used to assess heavy metal bioavailability within the system as a function of metal speciation in the wetland sediments. Results indicate hydrology is the most important variable in the design and establishment of the tailings wetland and suggest a wetland cover is an ecologically viable alternative for pyritic tailings which are feasible to flood. Ecological data indicate that in terms of species richness and diversity, the tailings-wetland was exhibiting the ecological characteristics of natural wetlands within two years. Ata indicate that pH and conductivity in the tailings-wetland were not adversely impacted by the acid-generating potential or sulphate concentration of the tailings substrate and its porewater. Similarly, no enhanced seasonal impacts from sulphate or metals in the water column, nor adverse impacts on the final water quality of the outflows, were detected. Mean total metal concentrations in the sediments of the tailings-wetland indicate no significant adverse mobilisation of metals into the peat substrate from the tailings. Correlation analyses indicate a general increase in sediment metal concentration in this wetland with increasing water depth and pH, and a corresponding decrease in the metal concentrations of the water column. Sediment extractions also showed enrichment of Cd, Fe, Pb and Zn in the oxidisable fraction (including sulphides and organic matter) of the tailings-wetland sediments. These data suggest that adsorption and coprecipitation of metals is occurring from the water column of the tailings wetland with organic material at increasing depths under reducing conditions. The long-term control of metal bioavailability in the tailings wetland will likely be related to the presence and continual build-up of organic carbon binding sites in the developing wetland above the tailings. Metal speciation including free-metal ion concentration and the impact of physico-chemical parameters particularly pH and organic matter, were investigated to assess ecotoxicological risk. Results indicate that potentially bioavailable metals (the sum of the exchangeable and reducible fractions) within the tailings wetland are similar to values cited for natural wetlands. Estimated free-metal ion concentrations calculated from geochemical regression models indicate lower free-metal ion concentrations of Cd in the tailings wetland than natural wetlands and slightly higher free-metal ion concentrations of Pb and Zn. Increased concentrations of metals in roots, rhizomes and stems of emergent macrophytes did not occur in the tailings wetland. Even though a substantial number of Typha latifolia plants were found rooting directly into tailings, elevated metals were not found in these plant tissues. Phragmites also did not exhibit elevated metal concentrations in any plant tissues. Typha and Phragmites populations appear to be exhibiting metal-tolerant behaviour. The chemistry of the water column and sediments in Silvermines wetland were also investigated and were much more indicative of a wetland system impacted by heavy metal contamination than the tailings-wetland. Mean Dc, Fe, Mn, Pb and Zn concentrations in the water column and sediments of Silvermines wetlands were substantially higher than in the pilot wetlands and closely approximate concentrations in these matrices contaminated with metals from mining. In addition, mean sulphate concentration in Silvermines wetland was substantially higher and is closer to sulphate concentrations in waters associated with mining. Potentially bioavailable metals were substantially elevated in Silvermines wetland in comparison to the pilot wetlands and higher than those calculated for natural rive sediments. However, Fe oxy-hydroxide concentrations in Silvermines sediments are also much higher than in the pilot wetlands and this significantly impacts the concentration of free-metal ions in the sediment porewater. The free-metal ion concentrations for Pb and Zn indicate that Silvermines wetland is retaining metals and acting as a treatment wetland for drainage emanating from Silvermines tailings dam.