University of Limerick Research Repository

Recent Submissions

  • PublicationOpen Access
    Characterisation of potential interactions between urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) and whey protein isolate
    (Elsevier, 2025-07-24) Byrne, Maria P.; Forrestal, Patrick J.; O’Callaghan, Tom F.; Rahman, Niharika; Ray, Aishwarya; Danaher, Martin; Corrigan, Bernard M.; Nkwonta, Chikere G; Richards, Karl; Garavand, Farhad; Cummins, Enda; Hogan, Sean A.
    Urea fertilizer augmented with the urease inhibitor (UI) N-(n-butyl)-thiophosphoric triamide (NBPT), is used to stabilize nitrogen and reduce greenhouse gas emissions. Although studies have shown that NBPT does not enter milk via cattle grazing on NBPT-treated fields, questions remain about its potential to impact milk components were it inadvertently to enter the dairy supply chain. The aim of this study was to examine possible effects of NBPT on the chemistry and functionality of whey protein isolate (WPI). NBPT raised the peak denaturation temperature of WPI (p < 0.05) and resulted in increased hydrogen bonding and β-sheet formation. NBPT reduced the viscosity of WPI and caused faster gelation. NBPT had a competitive adsorption advantage at the air-water interface (p < 0.05) compared to WPI. Microscopy imaging of WPI-NBPT gels revealed increased protein aggregation. Overall, NBPT modified the structure and functionality of WPI, primarily through non-covalent interactions.
  • PublicationOpen Access
    Integrated analytical approach to micro- and macroalgae: tailored extraction strategies for sustainable biorefineries
    (American Chemical Society, 2026-01-14) Trubetskaya, Anna; Haseneder, Roland; Herdegen, Volker; Leimbrock, Luis; Pisano, Italo; Joseph, Yvonne; Vogt, Carla; Kaschabek, Stefan Rudolf; Zuber, Jan
    This study evaluates the solvent-dependent extraction of Arthrospira platensis and Ascophyllum nodosum to guide sustainable marine biorefinery design. SOXTHERM rapid extractions were performed with n-hexane, ethanol−water (1:1, v/v), and water under controlled severity (3 h,n = 2). Ethanol−water consistently delivered the highest yields for A. platensis (25% DW ± 2.2) and A. nodosum (26% DW ± 2.2), with differences confirmed by a permutation test (p < 0.05). Hexane selectively enriched lipophilic fractions, whereas water favored polar constituents. For A. platensis, ethanol−water exceeded hexane (Δ20.3% DW ± 2.5) and water (Δ15.0% DW ± 1.2). For A. nodosum, differences were smaller versus water (Δ3.5% DW ± 3.6) but pronounced versus hexane (Δ23.5% DW ± 1.5). A. platensis extracts were protein-rich and contained long-chain polyunsaturated fatty acids, while A. nodosum extracts exhibited a high mineral content and structural carbohydrates. Ultra-high-resolution FT-ICR-MS revealed thousands of molecular features, including putative lipid-like and nitrogenous species; all structural assignments remain putative without MS/MS confirmation. Notably, biopterin analogues were detected in A. platensis water extracts, and polyphenolic signatures dominated A. nodosum ethanol−water extracts. Operationally, ethanol−water is recommended for scouting wide compositional space, while processing micro- and macroalgae requires desalting and antifoam strategies to mitigate foaming during polar extractions.
  • PublicationOpen Access
    Differentiating alzheimer’s Aβ isoforms coaggregated in cerebrospinal fluid via single-particle imaging
    (American Chemical Society, 2026-01-14) Henry, Lily; Bhattacharya, Shayon; Bergaglio, Talia; Pinotsi, Dorothea; Nirmalraj, Peter Niraj
    Amyloid polymorphism can reflect Alzheimer’s disease (AD) stages. This paper demonstrates that amyloid β (Aβ) peptides, primarily Aβ-40 and Aβ-42 (implicated in AD pathology), present in cerebrospinal fluid (CSF), can be differentiated, and their morphology studied in detail using fluorescence-based super-resolution and atomic force microscopy (AFM). An inhibitory effect of Aβ-40 on Aβ-42 protein aggregation, marked by Aβ-40 oligomers colocalizing along the Aβ-42 fibril backbone, was resolved at the single-particle level. Molecular dynamics simulations revealed that coaggregation is modulated by the ionic environment in CSF, where calcium ions form bridges between Glu residues of Aβ-40 and Aβ-42, known to stabilize the fibril structure. This ion-mediated tethering compacts Aβ-40 and kinetically traps the fibril−oligomer interface, thus reducing fibril elongation. The isoform-specific imaging method further allowed us to distinguish Aβ-40 and Aβ-42 aggregates from oligomers to mature fibrils in the CSF of AD patients, and the nanoscopic differences in aggregate sizes were quantified from the AFM topographs. Such a protein characterization approach, which is not limited by analyte size or shape and is capable of fingerprinting Aβ aggregates in CSF, could be used in clinical settings to monitor the progression of Alzheimer’s disease and related pathologies
  • PublicationOpen Access
    Data-Driven, real-time diagnostics of 5G and Wi-Fi networks using mobile robotics
    (MDPI, 2025-11-16) O'Brien, William; Dooley, Adam; Penica, Mihai; McGrath, Sean; O'Connell, Eoin
    Wireless connectivity plays a pivotal role in enabling real-time telemetry, sensor feedback, and autonomous navigation within Industry 4.0 environments. This paper presents a ROS 2-based mobile robotic platform designed to perform real-time network diagnostics across both private 5G and Wi-Fi technologies in a live smart manufacturing testbed. The system integrates high-frequency telemetry acquisition with spatial localization, multi-protocol connection analysis, and detailed performance monitoring. Metrics such as latency, packet loss, bandwidth, and IIoT (Industrial Internet of Things) data stream health are continuously logged and analysed. Telemetry is captured during motion and synchronously stored in an InfluxDB time-series database, enabling live visualization through Grafana dashboards. A key feature of the platform is its dual-path transmission architecture, which provides communication redundancy and allows side-by-side evaluation of network behaviour under identical physical conditions. Experimental trials demonstrate the platform’s ability to detect roaming events, characterize packet loss, and reveal latency differences between Wi-Fi and 5G networks. Results show that Wi-Fi suffered from roaming-induced instability and packet loss, whereas 5G maintained stable and uninterrupted connectivity throughout the test area. This work introduces a modular, extensible framework for mobile network evaluation in industrial settings and provides practical insights for infrastructure tuning, protocol selection, and wireless fault detection.
  • PublicationOpen Access
    Review of tensile anisotropy in laser powder bed fusion 316L stainless steel: Build orientation effects and optimisation using machine learning
    (Elsevier, 2025-09-01) Jagannati, Venumurali; Gurram, Mariyadas; Turaka, Seshaiah; Naidu B, Vishnu Vardhana; Verma, Govind Kumar; Krishnan, Pradeep Kumar; Sarimalla, Rambabu; Sebaey, Tamer A.; Bandaru, Aswani Kumar
    Laser powder bed fusion (LPBF) is an advanced additive manufacturing technique that enables the production of near-net-shape metallic parts with complex geometries. Among commonly used alloys, 316L stainless steel stands out due to its excellent mechanical strength, corrosion resistance, and suitability for LPBF. One critical parameter influencing the quality and performance of LPBF-printed parts is build orientation (BO), which significantly affects microstructure, mechanical properties, and anisotropy. This review consolidates findings from numerous studies that examine the influence of BO on tensile anisotropy, melt pool morphology, microstructure, and crystallographic texture of LPBF-manufactured 316L stainless steel. A comparative analysis of ultimate tensile strength, yield strength, and elongation across different BOs is presented, supported by characterisation techniques such as light optical microscopy, scanning electron microscopy, and electron backscatter diffraction. Although extensive research has been conducted, no specific BO has consistently improved tensile anisotropy. As a result, selecting an optimal BO remains a significant challenge. Several studies have introduced optimisation frameworks and automated tools to identify optimal BOs for various materials. In recent years, machine learning (ML) has been applied to refine optimisation models, thereby improving dimensional accuracy, surface finish, and mechanical performance. However, there is a notable gap in the literature regarding ML applications that specifically address tensile anisotropy. This review identifies opportunities to enhance anisotropic behaviour in LPBF 316L stainless steel parts through ML-assisted optimisation of BO, to achieve greater mechanical uniformity within a single printed component.