http://hdl.handle.net/10468/460 2013-05-21T10:55:18Z 2013-05-21T10:55:18Z McGarrigle, E. V. Deane, J. P. Leahy, Paul G. http://hdl.handle.net/10468/1010 2013-03-26T03:09:18Z 2013-07-01T00:00:00Z

How much wind energy will be curtailed on the 2020 Irish power system? McGarrigle, E. V.; Deane, J. P.; Leahy, Paul G. This paper describes a model of the 2020 Irish electricity system which was developed and solved in a mixed integer programming, unit commitment and economic dispatch tool called PLEXOS. The model includes all generators on the island of Ireland, a simplified representation of the neighbouring British system including proposed wind capacity and interconnectors between the two systems. The level of wind curtailment is determined under varying levels of three influencing factors. The first factor is the amount of offshore wind, the second is the allowed limit of system non-synchronous penetration (SNSP) and the third is inclusion or exclusion of transmission constraints. A binding constraint, resulting from the 2020 EU renewable energy targets, is that 37% of generation comes from wind. When the SNSP limit was increased from 60% to 75% there was a reduction in wind curtailment from 14% to 7%, with a further reduction when the proportion of wind capacity installed offshore was increased. Wind curtailment in the range of SNSP limit of 70-100% is influenced primarily by the inclusion of transmission constraints. Large changes in the dispatch of conventional generators were also evident due to the imposition of SNSP limits and transmission constraints.

2013-07-01T00:00:00Z McAuliffe, Michael A. P. Ruth, Albert A. http://hdl.handle.net/10468/887 2013-03-08T03:02:22Z 2013-02-01T00:00:00Z

Typical tropospheric aerosol backscatter profiles for Southern Ireland: The Cork Raman lidar McAuliffe, Michael A. P.; Ruth, Albert A. A Raman lidar instrument (UCLID) was established at the University College Cork as part of the European lidar network EARLINET. Raman backscatter coefficients, extinction coefficients and lidar ratios were measured within the period 28/08/2010 and 24/04/2011. Typical atmospheric scenarios over Southern Ireland in terms of the aerosol load in the planetary boundary layer are outlined. The lidar ratios found are typical for marine atmospheric condition (lidar ratio ca. 20–25 sr). The height of the planetary boundary layer is below 1000 m and therefore low in comparison to heights found at other lidar sites in Europe. On the 21st of April a large aerosol load was detected, which was assigned to a Saharan dust event based on HYSPLIT trajectories and DREAM forecasts along with the lidar ratio (70 sr) for the period concerned. The dust was found at two heights, pure dust at 2.5 km and dust mixing with pollution from 0.7 to 1.8 km with a lidar ratio of 40–50 sr.

2013-02-01T00:00:00Z Ryan, William James http://hdl.handle.net/10468/904 2013-01-23T03:00:13Z 2013-01-01T00:00:00Z

Investigation of global regulators influencing styrene metabolism and bioplastic synthesis in Pseudomonas putida CA-3 Ryan, William James The genetics and biochemistry involved in the biodegradation of styrene and the production of polyhydroxyalkanoates in Pseudomonas putida CA-3 have been well characterised to date. Knowledge of the role played by global regulators in controlling these pathways currently represents a critical knowledge gap in this area. Here we report on our efforts to identify such regulators using mini-Tn5 transposon mutagenesis of the P. putida CA-3 genome. The library generated was subjected to phenotypic screening to identify mutants exhibiting a reduced sensitivity to the effects of carbon catabolite repression of aromatic pathway activity. Our efforts identified a clpX disrupted mutant which exhibited wild-type levels of growth on styrene but significantly reduced growth on phenylacetic acid. RT-PCR analysis of key PACoA catabolon genes necessary for phenylacetic acid metabolism, and SDS-PAGE protein profile analyses suggest that no direct alteration of PACoA pathway transcriptional or translational activity was involved. The influence of global regulators affecting the accumulation of PHAs in P. putida CA-3 was also studied. Phenotypic screening of the mini-Tn5 library revealed a gacS sensor kinase gene disruption resulting in the loss of PHA accumulation capacity in P. putida CA-3. Subsequent SDS-PAGE protein analyses of the wild type and gacS mutant strains identified post-transcriptional control of phaC1 synthase as a key point of control of PHA synthesis in P. putida CA-3. Disruption of the gacS gene in another PHA accumulating organism, P. putida S12, also demonstrated a reduction of PHA accumulation capacity. PHA accumulation was observed to be disrupted in the CA-3 gacS mutant under phosphorus limited growth conditions. Over-expression studies in both wild type CA-3 and gacS mutant demonstrated that rsmY over-expression in gacS disrupted P. putida CA-3 is insufficient to restore PHA accumulation in the cell however in wild type cells, over-expression of rsmY results in an altered PHA monomer compositions.

2013-01-01T00:00:00Z Jackson, Stephen A. http://hdl.handle.net/10468/1037 2013-04-10T02:00:17Z 2013-01-01T00:00:00Z

Exploiting the diverse microbial ecology of marine sponges Jackson, Stephen A. Marine sponges (phylum Porifera) are the oldest extant metazoan animals on earth and host large populations of symbiotic microbes: Bacteria, Archaea and unicellular Eukaryota. Those microbes play ecological functions which are essential to the health of the host including carbon, nitrogen and sulfur cycling as well as host defence through the production of bioactive secondary metabolites which protect against infection and predation. The diversity of sponge-associated microbes is remarkable with thousands of OTUs reported from individual sponge species. Amongst those populations are sponge-specific microbes which may be specific to sponges or specific to sponge species. While marine natural product discovery concerns many animal phyla, Porifera account for the largest proportion of novel compounds. Evidence suggests that many of these compounds are the products of symbiotic microbes. Descriptions of sponge-associated microbial community structures have been advanced by the development of next-generation sequencing technologies while the discovery and exploitation of sponge derived bioactive compounds has increased due to developments in sequence-based and function-based metagenomics. Here, we use pyrosequencing to describe the bacterial communities associated with two shallow, temperate water sponges (Raspailia ramosa and Stelligera stuposa) from Irish coastal waters and to describe the bacterial and archaeal communities of a single sponge species (Inflatella pellicula) from two different depths in deep waters in the Atlantic Ocean, including at a depth of 2900m, a depth far greater than that of any previous sequence-based sponge-microbe investigation. We identified diverse microbial communities in all sponges and the presence of sponge-specific taxa recruiting to previously described and novel spongespecific clusters. We also identified archaeal communities which dominated sponge-microbe communities. We demonstrate that sponge-associated microbial communities differ from seawater communities indicating host selection processes. We used sequence-based metagenomic techniques to identify genes of potential industrial and pharmacological interest in the metagenomes of various sponge species and functionbased metagenomic screening in an attempt to identify lipolytic and antibacterial activities from metagenomic clones from the metagenome of the marine sponge Stelletta normani. In addition we have cultured diverse bacterial species from sponge tissues, many of which display antimicrobial activities against clinically relevant bacterial and yeast test strains. Other isolates represent novel species in the genus Maribacter and require emendments to the description of that genus.

2013-01-01T00:00:00Z