Trinity in Separate \u27Secret\u27 Discussions With DIT

The separate discussions with DIT are looking at all possible forms of potential alliance such as joint degrees, shared services and even joint staff appointments

New Campus Will Create 4,500 Jobs in Construction.

UP TO 4,500 construction jobs will be created over 10 years in a planned new campus development, a report has revealed. A further 1,160 new posts are identified in a science and technology park, shops, offices, plus health and education facilities. The 73-acre site at Grangegorman is the planned new location of a campus for Dublin Institute of Technology which, at the moment, is spread around 40 centres in the city

The internal group space

In this article we describe dynamic structures and relationships that arise in the internal space of groups, a space which materializes from the unconscious internal world of each group member and within the group as a whole. We use keys and doors as metaphors to explicate our understanding of the internal dynamics. We give examples of how these metaphors can be used to understand the structure, the function and the relationships within the group. The possible connections of these ideas to other theoretical frameworks are discussed

CFD modelling of wind flow over complex and rough terrain

A model has been developed using the general-purpose Navier-Stokes solver CFX4 to simulate Atmospheric Boundary Layer flow over complex terrain. This model has been validated against the measured data from the Askervein Hill experiment, and has been shown to perform well. The CFD model is also compared to the WAsP linear model of wind flow over topography, and a significant improvement is noted for flow over complex topography. Boundary conditions, gridding issues and sensitivity to other solver parameters have all been investigated. An advanced roughness model has been developed to simulate flow over forest canopies, using a resistive body force within the canopy volume. The model is validated against measured data for simple 2D cases, and for a complex 3D case over real topography. The model is shown to give a more physically realistic profile for the wind speed in and just above forest canopies than the standard roughness length model used in most CFD simulations. An automated methodology for setting up CFD simulations using the models described has been developed. A custom pre-processing package to implement this has been written, to enable the use of the CFD methodology in a commercial environment

Evaluation of the Potential of Nanofluids Containing Different Ag Nanoparticle size Distributions for Enhanced Solar Energy Conversion in Hybrid Photovoltaic-Thermal (PVT) Applications

Hybridising photovoltaic and photothermal technologies into a single system that can simultaneously deliver heat and power represents one of the leading strategies for generating clean energy at more affordable prices. In a hybrid photovoltaic-thermal (PVT) system, the capability to modulate the thermal and electrical power output is significantly influenced by the spectral properties of the heat transfer fluid utilised. In this study, we report on one of the first experimental evaluations of the capability of a multimodal silver nanofluid containing various particle shapes and particle sizes to selectively modulate the solar energy for PVT applications. The diverse set of particle properties led up to a 50.4% enhancement in the solar energy absorbed by the nanofluid over the 300nm—550nm spectral region, where silicon is known to exhibit poor photovoltaic conversion performances. This improved substantially the absorption of solar energy, with an additional 18–129Wm−2 of thermal power being generated by the PVT system. Along with the advancements made in the thermal power output of the PVT system, a decrease of 4.7–36.6Wm−2 in the electrical power generated by the photovoltaic element was noted. Thus, for every∼11Wm−2 increase of thermal power achieved through the addition of the nanoparticles, a reduction of∼3Wm−2 in the ability to generate clean electricity was sustained by the PVT. Despite the energy trade-offs involved under the conditions of the nanofluid, the PVT system cumulatively harvested 405Wm−2 of solar energy, which amounts to a total conversion efficiency of 45%. Furthermore, the economics of the additional energy harvested through merging of the two systems was found to reach an enhancement of 77% under certain European conditions

A transfer matrix approach to aid in the design and optimization of hybrid advanced passive structures for enhancing photovoltaic efficiency

The addition of a luminescent down-shifting (LDS) layer directly onto a photovoltaic (PV) cell introduces additional loss mechanisms within the system. The combination of non-ideal photo-luminescent materials encapsulated within a limited range of viable host materials, with the increased reflection losses arising from the newly created interface represent losses which must be overcome for LDS to offer an enhancement to the underlying cells efficiency. Exploiting the interaction between the highly enhanced electric fields established close to a metal nanoparticles (MNP’s) surface is one route aimed at mitigating the poor optical properties of the luminophore-host combinations available. Alternative approaches, aimed at addressing the other loss mechanisms within such a system have gone relatively unexplored. Exploiting the non-ideal nature of the photo-luminescent materials available, offers a possibility of recycling the photons which previously did not undergo photoluminescence while also addressing the reflection losses through the inclusion of selectively reflecting optical structures. The hybrid device designs, incorporating single- and double layer- antireflection coatings composed of commonly available materials offer enhancements in the underlying PV cells performance of 8% - 30% depending upon the design criteria established. The transfer matrix approach adopted allowed the impact of individual design considerations on the reflection suppression capabilities of the structure, as well as their impact on the underlying cells efficiency to be readily determined

Development of poly-vinyl alcohol stabilized silver nanofluids for solar thermal applications

Nanofluids offer the potential to address the low thermal conductivities found in conventional heat transfer fluids, through their unique electrical, optical and thermal properties, but their implementation remains restricted due to absorption and stability limitations. Here, we characterize and exploit the distinctive plasmonic properties exhibited by polyvinyl-alcohol stabilized silver nanostructures by tuning their absorption and thermal properties through controlling the nanoparticle size, morphology and particle-size distribution configuration at the synthesis stage. The photo-thermal efficiency of different water-based silver nanofluids under a standard AM1.5G weighted solar spectrum were explored, the influence of each of these components on the resulting fluids performance within a direct absorption solar thermal collection system being considered. Nanofluids, containing an extensive ensemble of particle size-distributions (5 nm–110 nm in diameter) in addition to anisotropic particle morphologies (e.g. prisms, hexagons and other non-spherical geometries), exhibited a significant enhancement in the absorption and photo-thermal energy transfer. Enhancements of 5%–32% in the photo-thermal conversion efficiency were achieved, the enhancement being dependent upon the presence of multiple particle size-distributions and the particle concentration. The enhancement is influenced by the interactions occurring between the individual particle size-distributions but also by the collective behaviour of the particles ensemble. The critical particle diameter, above which the photo-thermal characteristics of the nanofluid become dominated by the larger sized particles present, was identified as 150 nm. The increased performance of these nanofluids, which adopt a more complex particle-size configuration, suggests that they can represent suitable candidates for solar-thermal applications

Combined Experimental and Modeling Analysis for theDevelopment of Optical Materials Suitable to Enhance theImplementation of Plasmonic-Enhanced Luminescent Down-Shifting Solutions on Existing Silicon-Based Photovoltaic Devices

The development of highly efficient solar collectors requires modulating the light interactions with the semiconducting materials. Incorporating luminescent species and metal nanoparticles within a semitransparent polymeric material (e.g., polymethyl methacrylate (PMMA)) leads to the formation of a plasmon-enhanced luminescent down-shifting (PLDS) layer, which offers a retrofittable approach toward expanding the wavelength range over which the conversion process can effectively occur. Adding antireflection coatings (ARCs) further controls the spectral response. However, with each additional component comes additional loss pathways. In this study, the losses related to light interactions with the PMMA and the ARCs have been investigated theoretically using a transfer matrix method and experimentally validated. Two proposed architectures were considered, and the deviations between the optical response of each iteration helped to establish the design considerations. The proposed structure-enhanced (SE) designs generated a predicted enhancement of 37 to 62% for the collection performance of a pristine monocrystalline-silicon solar cell, as inferred through the short-circuit current density (Jsc). The results revealed the synergies among the SE-design components, demonstrating that the spectral response of the SEs, containing a thin polymer framework and an ARC, can be tuned to minimize the reflections, leading to the solar energy conversion enhancement

Estimating the potential yield of small building-mounted wind turbines

The wind profile in the urban boundary layer is described as following a logarithmic curve above the mean building height and an exponential curve below it. By considering the urban landscape to be an array of cubes, a method is described for calculating the surface roughness length and displacement height of this profile. Firstly, a computational fluid dynamics (CFD) model employing a k-ϵ turbulence model is used to simulate the flow around a cube. The results of this simulation are compared with wind tunnel measurements in order to validate the code. Then, the CFD model is used to simulate the wind flow around a simple pitched-roof building, using a semi-logarithmic inflow profile. An array of similar pitched-roof houses is modelled using CFD to determine the flow characteristics within an urban area. Mean wind speeds at potential turbine mounting points are studied, and optimum mounting points are identified for different prevailing wind directions. A methodology is proposed for estimating the energy yield of a building-mounted turbine from simple information such as wind atlas wind speed and building density. The energy yield of a small turbine on a hypothetical house in west London is estimated. The energy yield is shown to be very low, particularly if the turbine is mounted below rooftop height. It should be stressed that the complexity of modelling such urban environments using such a computational model has limitations and results can only be considered approximate, but nonetheless, gives an indication of expected yields within the built environment