Techno-Economic and Sustainability Analysis of Potential Cooling Methods in Irish Data Centres

11% of Irish electricity was consumed by data centres in 2020. The Irish data centre industry and the cooling methods utilised require reformative actions in the coming years to meet EU Energy policies. The resell of heat, alternative cooling methods or carbon reduction methods are all possibilities to conform to these policies. This study aims to determine the viability of the resell of waste heat from data centres both technically and economically. This was determined using a novel application of thermodynamics to determine waste heat recovery potential in Irish data centres, and the current methods of heat generation for economical comparison. This paper also explores policy surrounding waste heat recovery within the industry. The Recoverable Carnot Equivalent Power (RCEP) is theoretically calculated for the three potential cooling methods for Irish data centres. These are air, hybrid, and immersion cooling techniques. This is the maximum useable heat that can be recovered from a data centre rack. This study is established under current operating conditions which are optimised for cooling performance, that air cooling has the highest potential RCEP of 0.39 kW/rack. This is approximately 8% of the input electrical power that can be captured as useable heat. Indicating that Irish data centres have the energy potential to be heat providers in the Irish economy. This study highlighted the technical and economic aspects of prevalent cooling techniques and determined air cooling heat recovery cost can be reduced to 0.01 €/kWhth using offsetting. This is financially competitive with current heating solutions in Ireland.

Open-porous magnesium-based scaffolds withstand in vitro corrosion under cyclic loading:A mechanistic study

The successful application of magnesium(Mg)alloys as biodegradable bone substitutes for critical-sized defects may be comprised by their high degradation rate resulting in a loss of mechanical integrity.This study investigates the degradation pattern of an open-porous fluoride-coated Mg-based scaffold immersed in circulating Hanks’Balanced Salt Solution(HBSS)with and without in situ cyclic compression(30 N/1 Hz).The changes in morphological and mechanical properties have been studied by combining in situ high-resolution X-ray computed tomography mechanics and digital volume correlation.Although in situ cyclic compression induced acceleration of the corrosion rate,probably due to local disruption of the coating layer where fatigue microcracks were formed,no critical failures in the overall scaffold were observed,indicating that the mechanical integrity of the Mg scaffolds was preserved.Structural changes,due to the accumulation of corrosion debris between the scaffold fibres,resulted in a significant increase(p<0.05)in the material volume fraction from 0.52±0.07 to 0.47±0.03 after 14 days of corrosion.However,despite an increase in fibre material loss,the accumulated corrosion products appear to have led to an increase in Young’s modulus after 14 days as well as lower third principal strain(εp3)accumulation(-91000±6361μεand-60093±2414μεafter 2 and 14 days,respectively).Therefore,this innovative Mg scaffold design and composition provide a bone replacement,capable of sustaining mechanical loads in situ during the postoperative phase allowing new bone formation to be initially supported as the scaffold resorbs.

Investigation of low grade thermal energy storage systems with phase changing materials

The use of phase changing materials(PCMs)for energy storage has been in the focus of scientific research for a while,primarily focusing on building cooling/heating applications due to favourable melting temperature ranges.In this paper we simulated the suitability of encapsulated Paraffin Wax on a small scale in a low temperature thermal energy storage system using COMSOL Multiphysics.Heat absorption and heating dynamics were analysed for different inlet designs and velocities,and the thermal gradient was evaluated across the tank geometry in a number of charging scenarios.Results show that paraffin wax proves to be a good storage medium based on its fast charging and good latent heat absorption.The study found that although an addition of a second inlet to the system yields higher final temperatures and improves the heat transfer rate,it does so minimally and therefore is not notably beneficial.Both designs follow the same heating dynamics independently on the final temperatures.Lastly,higher or lower velocities benefit the system based on the design.

Performance Evaluation of Calcium Alkali-treated Oil Palm/Pineapple Fibre/Bio-phenolic Composites

The utilisation of oil palm fibre(OPF)and pineapple leaf fibres(PALF)as reinforcement materials for bio-phenolic composites is growing especially in automotive lightweight applications.The major aim of this current study is to investigate the influence of alkali(Ca(OH)_(2)) treatment on pure and hybrid composites.The effects of enhancements in chemical interactions were evaluated by the Fourier-Transform Infrared Spectrometer(FTIR).Dynamic Mechanical Analysis(DMA)and Thermogravimetric Analysis(TGA)performance of untreated reinforcements(OPF and PALF)and treated(OPF/OPF)composites at varying temperature and noted sufficient interfacial bonding contributing towards the improvements in thermal stability.From DMA results,the storage modulus improved with treated composites while the damping factor was reduced.Furthermore,the treated hybrid composites exhibited significant improvements in thermal stability compared to untreated fibre composites.The results indicated that alkali calcium hydroxide(Ca(OH2(:T)incorporation in hybrid composites(OPF/PALF)results in increased tensile strength and modulus among all composites.Similarly,the alkali-treated(Ca(OH)_(2))-treated pure composite(T/50%PALF),and hybrid composites(T/1OPF.1PALF)exhibited better flexural strength as compared with other composites.In contrast,the T/50%PALF showed higher flexural stress of 78.2 MPa,while the flexural modulus was recorded at 6503 MPa.It can be proposed from the findings of this study that the alkali treatment(5%Ca(OH)_(2))can be utilised to improve the strength and efficiency of agriculture biomass to be used as reinforcements in composites.Additionally,the hybridisation of bio-fibre composites has the potential as a novel variety of biodegradable and sustainable composites appropriate for several industrial and engineering applications.