CUAL Repository (Connacht Ulster Alliance Libraries)
Not a member yet
852 research outputs found
Sort by
Photocatalytic activity indicator inks for probing a wide range of surfaces
Get PDFThree photocatalyst inks based on the redox dyes, Resazurin (Rz), Basic Blue 66 (BB66) and Acid Violet 7 (AV7, are used to assess the photocatalytic activities of a variety of different materials, such as commercial paint, tiles and glass and laboratory made samples of sol-gel coated glass and paint, which collectively exhibit a wide range of activities that cannot currently be probed by any one of the existing ISO tests. Unlike the ISO tests, the ink tests are fast (typically < 10 min), simple to employ and inexpensive. Previous work indicates that the Rz ink test at least correlates linearly with other photocatalytic tests such as the photomineralisation of stearic acid. The average time to bleach 90% of the key RGB colour component of the ink (red for Rz and BB66 inks) and green for AV7 ink) is determined, ttb(90), for eight samples of each of the different materials tested. Five laboratories conducted the tests and the results revealed an average repeatability and reproducibility of: ca. 11% and ca 21%, respectively, which compare well with those reported for the current ISO tests. Additional work on commercial self-cleaning glass using an Rz ink showed that the change in the red component of the RGB image of the ink correlated linearly with that of the change of absorbance (at 608 nm) (as measured using UV/Vis spectroscopy) and the change in the a* component of the Lab colour analysis of the ink, as measured using diffuse reflectance spectroscopy. As a consequence, all three methods generate the same ttb(90). The advantages of the RGB digital image analysis method are discussed briefly
An investigation into the detection and identification of OsHV-1 μvar virus and associated risk factors causing mortalities in Crassostrea gigas in Ireland.
Get PDFPart two of this study investigated the detection of OsHV-1 μvar and associated risk factors during mortality outbreaks. An epidemiological study was conducted during 2011. 17 bays from around the Irish Coast were selected, comprising of sites which have been endemically infected by the OsHV-1 μVar virus. Batches of Pacific oysters, Crassostrea gigas were selected in each of the 17 bays and were tracked through the study period in an effort to identify any associated management factors. Samples of C. gigas oysters were collected from selected stocks in each of the 17 bays to screen for OsHV-1μvar. In addition to pathogen screening and tracking stocks of oysters, environmental monitoring also took place, using sampling points which were located in the vicinity of the point where the samples were collected. From the analysis of risk factors in 2011, several factors were found significant during mortality outbreaks, including hatchery source, and OsHV-1 viral load in 2011 and the maximum water temperature recorded between June and August 2011. Multivariable risk analysis indicated that mortalities increased with temperature until a peak was reached. The current study provides some insights into mortality events affecting farmed Pacific oyster production in Ireland. The epidemiological study conducted found that batch mortality was lower in 2011, compared with earlier years, in association with lower OsHV-1 μvar viral loads
Environmental analysis of the use of poultry manure as fuel for combustion on broiler farms: a case study.
Get PDFFluidised Bed Combustion (FBC) technology is not new. It has been used in power plants for the last three decades and is considered very efficient for biomass combustion. The novelty of the FBC application in BHSL’s case consists of the combustion of poultry manure on farm with the same thermal efficiency (over 86%) as the combustion of biomass (e.g. wet wood chips). BHSL has successfully miniaturised the power plant design to produce up to 2 MWh heat in a unit which is small enough to locate on the site where the fuel is generated – ideal for agricultural and by product applications with high heat demands. BHSL’s FBC 500 boiler is capable of 500 kWh thermal output, which is sufficient to provide hot water at 850C required for distribution to poultry sheds for rearing broilers from day-old to fully grown. A case study was conducted in order to measure the efficiency of the BHSL energy system for broiler production and also to evaluate its environmental benefits. Environmental benefits were measured using Life Cycle Assessment (LCA), which compared the environmental impact of 3 scenarios: (1) where the poultry manure is used for land spreading as a fertiliser and the broiler houses are heated with LPG; (2) where the poultry manure is used for combustion in the FBC 500 to generate heat, most of which is used to heating the broiler houses; (3) where the poultry manure is used for the production of steam and electricity generation with the residual steam used for heating the poultry sheds (combined heat and power – CHP). The results of the analysis show that when poultry manure is used for combustion, a reduction up to 95% in LPG use, as well as reductions in eutrophication potential of 26-32% and acidification potential of 31-40% can be achieved. An improvement in birds’ welfare was also noticed as a result of the use of dry heat that can be supplied to the broiler houses by poultry manure conversion
A preliminary exploration of database performance for use with ‘big data’ projects in the aviation industry
Get PDFThis thesis will demonstrate the effectiveness of processing data for the airline industry using both a MariaDB and MongoDB database. Conclusions will be drawn on pertinent issues such as the performance of processing large datasets. It is difficult to research Big Data without encountering Hadoop as part of the process. Patel et al. (2012. p 1) describe it as the ‘optimal solution’ in their paper. They conclude that using Hadoop for Big Data processing is a favourable technology to use. However, this dissertation endeavours to research and test a viable alternative that is suitable for enterprise applications. It is for this reason that a MongoDB database, MongoDB and a MariaDB database, MariaDB have been selected for the purposes of this research. This thesis will endeavour to investigate the suitability of the airline industry making use of the data that is available to them which would enable them to specifically target passengers. It is also proposed that the results generated can be used for marketing purposes
An integrated approach to comparative assembly
No full textWe describe a novel approach to comparative assembly that directly integrates anchoring alignments into the contig assembly process, enabling the extension of contig construction through the boundaries of repeat nodes in a compressed de Bruijn graph. Our method exploits anchoring alignments, paired-read constraints and read threading as path selection heuristics while an assembly graph is transversed during contig construction. Tests and benchmarks against preeminent implementations of both comparative and denovo assembly models demonstrate that the approach can significantly increase the contiguity of an assembly without inducing a large number of misjoins and structural errors
An abundance estimate for humpback whales Megaptera novaeangliae breeding around Boa Vista, Cape Verde Islands
Get PDFThe abundance of humpback whales occurring around Boa Vista, Cape Verde Islands, was estimated by mark-recapture modelling. Photographs of markings on tail flukes of individual whales were collected during the breeding season. Sighting histories were constructed for each individual and an abundance of 171 animals was estimated using a Jolly-Seber mark-recapture model. Correcting for known biases arising due to sex-specific behaviour and temporary emigration insofar as possible, an estimate of 260 whales was obtained. This is significantly higher than the previous estimate of 99 humpback whales from this region. Due to limited survey effort it is not known how representative the study area is of the entire Cape Verde archipelago and this estimate may be considered to be biased low and serves as a minimum estimate. The high recapture probability (0.37) coupled with the low abundance is consistent with a small local population. The low survival rate (0.86) suggests possible emigration and further studies are needed to assess connectivity between humpback whales breeding in Cape Verde and other breeding locations. The amount of exchange between groups of whales breeding in Cape Verde and adjacent areas remains unknown. It is unclear whether the abundance estimate herein applies to part of an isolated population or part of a larger and continuous one
Assessment and utilisation of Zequanox for zebra mussel (Dreissena polymorpha) control in Irish waters
Get PDFSince the first arrival of the zebra mussel (Dreissena polymorpha) to Ireland in the early\ud
1990’s, there has been a rapid secondary spread of these highly invasive mussels within\ud
many Irish freshwater systems suitable for their establishment. This has resulted in\ud
direct invasive impacts to infested lakes, rivers and canals, both to the freshwater biota\ud
and to man-made infrastructure. The availability of an effective, yet environmentally\ud
benign, mussel control product to replace those currently used, such as chlorine and\ud
other biocides is particularly needed to mitigate mussel fouling impacts in drinking\ud
water plants and other infested facilities.\ud
Zequanox® is a selective control product for dreissenids, i.e. zebra and quagga\ud
(D.rostriformis bugensis) mussels. It is a natural biocide, with the active ingredient\ud
being dead Pseudomonas fluorescens CL145A cells; a patented strain of a naturally\ud
occurring soil bacterium, which works by disrupting the mussels’ digestive system. This\ud
product was developed in the USA, and has been tested and used in a number of North\ud
American trials, with the aim of commercialising a cross-continental, effective and\ud
regulatory compliant control product.\ud
Research outputs from this thesis were utilised in the Zequanox regulatory application\ud
for commercial use within Europe. Ecotoxicology trials were carried out on nine species\ud
found commonly in Irish ecosystems. Results indicated that Zequanox does not\ud
negatively affect eight of these organisms at concentrations and treatment lengths\ud
required to get a >80% zebra mussel kill.\ud
Field trials were carried out to demonstrate the effectiveness of Zequanox in industry\ud
and open water and to monitor water quality during and after treatment. These included\ud
a biobox trial at a drinking water treatment plant and an open water trial in a canal. Both\ud
trials achieved high levels of zebra mussel mortality (up to 81%) and provided insights\ud
into practical application techniques.\ud
Additional laboratory assays were undertaken to determine the exact response\ud
relationship of juvenile zebra mussels to Zequanox. The results showed that juvenile\ud
mortality, on both experimental and control plates, are decreased with reduced handling,\ud
with subsequent recommendations given for future juvenile treatment and counting\ud
procedures in the field.\ud
After the two field trials (drinking water treatment plant and canal) were undertaken, it\ud
was apparent that mortality rates after treatment were lower in Ireland and also took\ud
longer to occur than similar trials carried out in North America. It was suspected that the\ud
higher water temperatures during North American trials (>25C) meant that the zebra\ud
mussels were more metabolically active and therefore ingested more product. A number\ud
of comparative studies commenced to evaluate the effect of Zequanox on North\ud
American zebra mussels versus European zebra mussels. The results of this study\ud
showed that under the same temperature regimes mortality is similar. North American\ud
mussels were found to ingest more product in the initial eight hours, however by 24\ud
hours, product concentration was similarly low for both mussel groups. The results of\ud
this trial allowed for industry recommendations to be made regarding the timing of\ud
treatments in Europe.\ud
In conclusion this research has bridged the gap between the use of Zequanox in Europe\ud
and North America, showing there is potential for Zequanox to control zebra mussels in\ud
Europe not only in industry but also in open water. This study has also demonstrated\ud
Zequanox’s potential to replace chlorine as the traditionally used control method,\ud
thereby reducing the environmental impact of mussel control on freshwater ecosystems
The pollution potential of road salt on aquatic environments in Ireland
No full textRoad salt or rock salt as it is sometimes known, is a commonly used de-icing material\ud
and is used throughout Ireland by local authorities (i.e. county councils), private road\ud
operators and members of the public during times of freezing weather. County\ud
councils, road authorities and private road operators apply road salt as required as part\ud
of their winter road maintenance programs.\ud
The road salt used is predominantly sodium chloride (NaCl) as it is relatively\ud
inexpensive when compared to other de-icing agents, easy to manufacture and readily\ud
available.\ud
A number of negative environmental effects and a loss in water quality have been\ud
associated with stormwater (melt water) containing dissolved road salt entering fresh\ud
waterbodies in the vicinity of roads which are de-iced with sodium chloride.\ud
This study uses the M3 motorway in County Meath as a case study. International\ud
findings from other studies on road salt are used to illustrate the potential pollution\ud
threat posed by spreading road salt. Recognised best practice for the mitigation of this\ud
pollution threat is reviewed and stormwater treatment methods along the M3 are\ud
evaluated with regard to reducing sodium chloride levels in stormwater run-off.\ud
This study has found that treated stormwater from the M3 does not cause a significant\ud
elevation in chloride levels. The treatment methods applied to the stormwater may\ud
remove the chloride from road salting and the receiving waterbodies dilute the\ud
chloride in the stormwater to concentrations that are below recognised toxic limits.\ud
A ‘Salt Management Plan’ is the key mitigation measure. Awareness of maintenance\ud
companies and staff to the pollution potential of road salt, training of employees, well\ud
maintained salt spreading equipment, pre-wetting of salt and active management of\ud
road maintenance particularly in areas where roads run in close proximity to\ud
waterbodies are essential to limit the threat of road salt to water quality and the\ud
environment
The philosophical universe and the information systems research journey: a hitchhiker's guide to a virtual galaxy
Get PDFThere is concern among information systems (IS) scholars that the lack of philosophical\ud
engagement and conviction among the research community threatens the future integrity and\ud
creativity of the research process. The paper seeks to respond to Weber’s call for IS researchers\ud
to clearly present their “ontological and epistemological assumptions” and to accept Myers’\ud
invitation for “further reflection and debate on the important subject of grounding interpretive\ud
research methodology”. The approach of the paper is to present a self-reflective case study,\ud
following Schön, of the author’s doctoral research journey. The paper aims to make a\ud
contribution by: presenting the work of two philosophers new to the IS discipline and proposing\ud
a dynamic model that opens IS research to engagement with the complex philosophical\ud
universe. The argument is developed using analogy and by describing the author’s journey\ud
towards a philosophical system that reflects his worldview