http://hdl.handle.net/10453/35199 2026-04-26T16:05:26Z http://hdl.handle.net/10453/194809 Title: Everything, everywhere, all at once: undersea surveillance coverage in the Indo-Pacific Authors: Milledge, T 2026-04-21T00:00:00Z http://hdl.handle.net/10453/194806 Title: Revealing the influence of solvent polarity and refractive index on whispering gallery mode-based laser sensors. Authors: Li, J; Li, D; Fang, G; Guo, C; Nie, N; Sun, X; Pu, X; Jin, Y; Chen, Y-C; Zhang, Y Abstract: Whispering-gallery-mode (WGM) lasers are highly sensitive sensing tools in solution-based environments, but their performance is influenced by multiple factors, leading to complex spectral shifts. In this study, we decode the influence of solvent polarity on the WGM laser sensors, exploring its interaction with solvent refractive index (RI) in optofluidic systems. A binary polarity solvent of ethanol (EtOH) and ethylene glycol (EG) containing rhodamine 6G (Rh6G) is utilized as the lasing gain medium. Experimental results indicate that increasing solvent polarity induces a redshift in the lasing wavelength, while rising RI lowers the quality factor (Q-factor), causing a competing blueshift. These opposing effects collectively impact the overall performance of the sensors. Based on these observations, we propose a predictive framework for optimizing WGM laser sensors across different Q-factor levels, offering valuable insights for sensor design and fabrication. 2025-10-06T00:00:00Z http://hdl.handle.net/10453/194805 Title: Resilience of mangroves to climate and land-use changes in the Pacific Islands Authors: Jorquera, E; Rodríguez, JF; Saco, PM; Sandi, S; Quijano-Baron, J; Breda, A Abstract: Mangrove wetlands in Pacific Islands are vital ecosystems that provide important services such as habitat for marine species, flood protection and carbon storage. They occupy low-lying areas that are at risk of sea level rise (SLR), which, combined with anthropogenic pressures exerted on adjacent zones can lead to destabilising effects on these ecosystems. Their resilience to climate and land use changes is closely related to sediment availability, as mangroves can vertically adjust their soil surface (accretion) by trapping sediment and building root mass, offsetting SLR. In this contribution, an ecogeomorphological model is applied to a mangrove wetland site in Vanua Levu Island, Fiji, to predict its evolution over the next 100 years and to assess its resilience under five different scenarios of climate and land use change. Scenarios consider the SSP5-8.5 pathway SLR and include a scenario with current conditions, two scenarios with different levels of deforestation in the catchment, one scenario with increases in temperature and rainfall intensity, and a scenario with conservation practices to reduce sediment from the catchment. Changes in the catchment are assessed using a hydro-sedimentological model previously calibrated, and produce increases in sediment supply to the wetland for all scenarios except the conservation scenario. Changes in sediment supply are incorporated into the ecogeomorphological model, which is able to quantify improvements in the resilience of the wetland due to increases in sediment. Improvements in resilience are not enough to prevent substantial wetland losses (30 % to 60 %) because mangroves cannot colonise new areas due to topographic constraints and a manmade embankment that prevents tidal incursion. The methodology uses numerical models that are set up and verified with regional information and remote sensing derived data, so it has enormous potential for the assessment of wetland vulnerability in other mangrove wetlands of the world with limited ground information. 2025-12-31T00:00:00Z http://hdl.handle.net/10453/194804 Title: Robust quantification of spectral transitions in perturbed quantum systems Authors: Szabo, Z; Gehr, S; Facchi, P; Yuasa, K; Burgarth, D; Lonigro, D Abstract: A quantum system subject to an external perturbation can experience leakage between uncoupled regions of its energy spectrum separated by a gap. To quantify this phenomenon, we present two complementary results. First, we establish time-independent bounds on the distances between the true dynamics and the dynamics generated by block-diagonal effective evolutions constructed via the Schrieffer-Wolff and Bloch methods. Second, we prove that, under the right conditions, this leakage remains small eternally. That is, we derive a time-independent bound on the leakage itself, expressed in terms of the spectral gap of the unperturbed Hamiltonian and the norm of the perturbation, ensuring its validity for arbitrarily large times. Our approach only requires a finite spectral gap, thus accommodating continuous and unbounded spectra. Finally, we apply our bounds to specific systems of practical interest. 2025-09-02T00:00:00Z