http://bura.brunel.ac.uk/handle/2438/8625 2026-06-13T14:33:56Z http://bura.brunel.ac.uk/handle/2438/33426 Title: Investigating OME3-diesel droplet evaporation, combustion dynamics, and soot characterization Authors: Mazari, F; Megaritis, T Abstract: The combustion behavior of fuel droplets plays a crucial role in controlling emissions and combustion efficiency in internal combustion engines. Droplet heating, evaporation, and burning characteristics strongly influence ignition delay, combustion duration, and soot formation. Oxymethylene ethers (OMEs), particularly oxymethylene ether-3 (OME₃), have attracted interest as drop-in diesel alternatives due to their high oxygen content and clean combustion potential. This study experimentally investigates the combustion of a single fuel droplet suspended on a thermocouple and exposed to a controlled environment at 500 °C and atmospheric pressure. Four fuels were examined: neat diesel and diesel blends containing 20, 40, and 60 vol% OME₃. High-speed imaging was used to analyze ignition delay, combustion duration, and flame luminosity, complemented by scanning electron microscopy (SEM) of collected particulates. Increasing OME₃ content significantly reduced ignition delay (by ∼ 65–70% for D40-O60) while increasing combustion duration by ∼ 25–30%. Flame luminosity decreased markedly, indicating suppression of macroscopic soot. This behavior is primarily attributed to the high oxygen content of OME₃, which promotes oxidation pathways that limit soot precursors formation. SEM analysis revealed a shift toward finer particles, with sub-micrometer particle counts increasing from ∼ 120 mm⁻² to ∼ 340 mm⁻². These results demonstrate that reduced flame luminosity does not necessarily correspond to lower particulate emissions but instead reflects a shift toward ultrafine particle formation. Overall, OME₃ modifies combustion behavior by reducing visible soot while increasing ultrafine particle number density, highlighting a critical trade-off in oxygenated fuel performance. Description: Data availability: Data will be made available on request. 2026-05-28T00:00:00Z http://bura.brunel.ac.uk/handle/2438/33414 Title: Experimental Study on Integrated Hydrogen-Based Cooling, Heating, and Power Generation Authors: Kumar, A; Tassou, SA; Tavares, J Abstract: To address rising energy demand and global warming, green hydrogen-based energy systems offer a promising alternative to fossil fuels. This study investigates the coupling of an Anion Exchange Membrane (AEM) electrolyser, metal hydride (MH) storage, and a Proton Exchange Membrane fuel cell (PEMFC) for integrated hydrogen storage, power generation, and thermal management. Hydrogen produced at approximately 35 bar by the electrolyser is stored in an MH reactor, with auxiliary gaseous storage for excess hydrogen, and supplied to a 4 kW fuel cell (FC) operating at loads between 1 and 3.5 kW. The MH reactor, based on a shell-and-tube heat exchanger design, contains 20 kg of AB₅ alloy with a hydrogen storage capacity of ∼300 g (∼1.5 wt.%). Experimental results demonstrate stable system operation, with heating output during the absorption half cycle ranging from ∼3.5 to 4.4 MJ for various absorption conditions, and cooling output during desorption varying from ∼0.2 to 0.75 kW for load conditions ranging between 1.0 and 3.5 kW. With MH coupling, the FC efficiency reached 53%, with optimal performance observed above 50% load. The results confirm the feasibility of MH-based hydrogen storage systems for combined power, heating, and cooling applications, particularly in transport energy systems. Description: Data availability: Data will be made available on request. 2026-06-08T00:00:00Z http://bura.brunel.ac.uk/handle/2438/33389 Title: A Hand-Guided Robotic Drill for Vestibular Implant Surgery—Feasibility of Preventing Membranous Labyrinth Rupture Authors: Stultiens, JJA; Du, X; Waterval, JJ; Pérez Fornos, A; Guinand, N; van de Berg, R Abstract: Importance: Progress in vestibular implantation offers hope for patients with bilateral vestibulopathy. However, surgically opening the semicircular canals risks breaching the membranous labyrinth, which may induce sensorineural hearing loss. A robotic drill sensing force and torque might prevent membranous labyrinth rupture. Primary objective: To assess the feasibility of force- and torque-based automatic cessation in a hand-guided robotic drill for fenestrating the bony semicircular canals without rupturing the membranous labyrinth. Secondary objective: To fit an electrode dummy through the fenestrations. Design: Feasibility study using human cadaveric temporal bones. Setting: Laboratory. Participants: Ten formalin-fixed human temporal bones. Intervention: After performing a cortical mastoidectomy and skeletonizing the semicircular canals, a hand-guided robotic drill was used to drill 2 fenestrations in each semicircular canal. A silicone electrode dummy was inserted through each fenestration. Main outcome measures: Proportion of fenestrations with intact membranous labyrinth, as evaluated with a surgical microscope. Proportion of fenestrations allowing electrode insertion without additional manipulation. Results: A total of 60 fenestrations were made in 30 semicircular canals from 10 temporal bones. Technical issues related to drill bit fixation occurred in 6 fenestrations. The remaining 54 fenestrations were all made without visible damage to the membranous labyrinth. In 81% of these fenestrations (44/54), the electrode could be advanced without requiring additional manipulation. The technical issue was related to improper alignment of the drill bit, leading to incorrect force and torque sensing. Conclusions: Force- and torque-based automatic cessation in a hand-guided robotic drill is feasible for fenestrating the bony semicircular canals without rupturing the membranous labyrinth. However, improved burr fixation is required for consistent and reliable performance. Relevance: The investigated approach holds potential to improve safety and precision in semicircular canal surgery, such as vestibular implantation. This may expand treatment options for patients with residual inner ear function. Description: Data availability statement: All data analyzed during this study are included in this published article. Results of the individual measurements are reported in Table 1.; Supplementary Material is available online at: https://journals.sagepub.com/doi/10.1177/19160216261433549#supplementary-materials . 2025-05-08T00:00:00Z http://bura.brunel.ac.uk/handle/2438/33362 Title: Characterisation of rate-dependent mode-II adhesive debonding based on a novel load–displacement curve parametrisation Authors: Jurković, D; Škec, L; Alfano, G Abstract: In this study, the mode-II rate dependence of an epoxy adhesive is investigated using end-notched flexure (ENF) tests conducted over loading speeds ranging from 0.1 to 5000 mm/min. To address the pronounced scatter typically observed in mode-II debonding tests, as well as the lack of a procedure for evaluation of the average load–displacement curve, a novel curve-parametrisation and statistical averaging framework is proposed. The load–displacement curves are represented using a set of parameters, enabling the construction of representative average curves for each loading speed and the quantification of parameter variability. The method allows the rate-dependent behaviour to be assessed over the entire load–displacement domain, rather than being restricted to the region typically used for the evaluation of the fracture resistance. The representative values of the critical energy release rate evaluated for each loading speed using the proposed method are in good agreement with the mean values obtained by a conventional specimen-by-specimen analysis. The results show a monotonic increase in mode-II fracture resistance with increasing loading speed, followed by a plateau at higher speeds. However, the proposed method reveals a continued monotonic evolution of the global response with loading speed, indicating that rate-dependent effects extend beyond the critical energy release rate alone. These findings demonstrate that the proposed parametrisation framework enables statistically robust characterisation of rate-dependent mode-II adhesive debonding and improved constitutive modelling. Description: Data availability: Research Link Provided. Dataset to be added after the paper is accepted (Original data) (Figshare) [at: https://doi.org/10.17633/rd.brunel.32535825]. 2026-05-26T00:00:00Z