The uncertainty introduced by inverter-based resources (IBRs) increasingly challenges secure and economic power system operation, as conventional deterministic optimal power flow (OPF) cannot rigorously capture the full range of optimal operating states. To address this, this paper devises a reachable OPF (ReachOPF) framework that reformulates OPF under uncertainty as a reachability problem of an augmented continuous-time ordinary differential equation (ODE) system. By embedding the OPF constraints into a preconditioned augmented-Lagrangian flow with residual filtering and parameter-as-state modeling, ReachOPF enables one-shot propagation of uncertainty through zonotopic reachable-set computation instead of repeated sampling. Case studies on 3-bus and 30-bus systems show that ReachOPF achieves guaranteed coverage of all Monte Carlo solutions with significantly reduced computational cost, demonstrating its rigor, scalability, and suitability for uncertainty-aware OPF analysis.
Fishing, especially within industrial sectors, is widely recognized as one of the most dangerous occupations in the world, as fishers are exposed to adverse physical and environmental risks. While legal frameworks in Nigeria provide occupational safety and labor protections for industrial fishers, inconsistencies in enforcement and compliance persist. Voluntary sustainability standards (VSS) have been promoted as market-based mechanisms to reduce risks, increase safety compliance, and improve working conditions. Despite their relevance, evidence of their impacts on industrial fisheries remains unclear. This study examines the effects of the Friend of the Sea (FOS) certification program on the occupational safety and working conditions of industrial fishers in Nigeria's Gulf of Guinea, Atlantic Ocean. A mixed methods approach was employed, integrating quantitative surveys with semi-structured interviews with key informant to facilitate triangulation among participants recruited from FOS-certified and Business as Usual (BAU) fishing companies. Bivariate analyses revealed that FOS-certified fishers were significantly more likely to have adequate safety equipment (98.0% vs. 74.8%), access to health personnel and emergency services (100% vs. 17.4%), and training opportunities (98.5% vs. 46.8%). Multivariate logistic regression confirmed these associations such that absence of safety equipment was associated with a 0.364 decrease in the probability of FOS certification; no injury history with a 0.291 increase; no exposure to unsafe conditions with a 0.400 increase; and lack of training access with a 0.535 decrease (all p < 0.001). These findings suggest that, despite statutory legal protections in Nigeria, participation of fishing companies in the FOS certification programme may enhance the implementation of safety standards and improve occupational health outcomes among industrial fishers.
Given that the configuration of bipolar plates in proton exchange membrane fuel cells plays a decisive role in the uniformity of reactant gas distribution, product water management, and overall output performance, this study focuses on optimizing the integral plate structure. It investigates the mechanisms by which operating pressure regulation, reactant flow arrangement, and cooling channel matching influence multiphase mass transport characteristics and electrochemical performance. For the cell configuration featuring fractal gas distribution zones and cathode with fine wavy channels (with an overall plate area of 96.023 cm 2 ), mass transport analysis reveals a relative error of up to 13.63% for oxygen at the cathode on a given cross-section, confirming that the cathode side is critical to improving reactant uniformity and water management. Further exploration of the reactant flow arrangement indicates that, under constant current density, the counter-flow configuration achieves more uniform water distribution in the cathode catalyst layer without compromising output performance. Investigations into operating pressure regulation show that as the operating pressure increases from 1.0 atm to 2.0 atm, the pressure drop in the cathode channels (CCH) decreases from 4817.036 Pa to 1597.201 Pa - a reduction of 66.8% - while the net output power density of the cell increases substantially by 25.0%. These results identify 2.0 atm as the optimal operating pressure that balances output performance with operational energy efficiency. Finally, with respect to the matching between cooling channels and reactant transport, it is found that adopting a flow scheme in which the coolant flows in the same direction as oxygen significantly suppresses local hotspots and reduces liquid water saturation within the CCHs, thereby achieving a higher steady-state output voltage. This finding provides a theoretical basis for the synergistic optimization of the cooling system.
AI agents may soon become capable of autonomously completing valuable, long-horizon tasks in diverse domains. Current benchmarks either do not measure real-world tasks, or are not sufficiently difficult to meaningfully measure frontier models. To this end, we present Terminal-Bench 2.0: a carefully curated hard benchmark composed of 89 tasks in computer terminal environments inspired by problems from real workflows. Each task features a unique environment, human-written solution, and comprehensive tests for verification. We show that frontier models and agents score less than 65% on the benchmark and conduct an error analysis to identify areas for model and agent improvement. We publish the dataset and evaluation harness to assist developers and researchers in future work at tbench.ai.
Baleen whales are key consumers in marine habitats that serve as vectors of nutrients, but their populations have been slow to recover from past commercial whaling due to their low reproductive rates and ongoing anthropogenic threats. Climate impacts have become central to the demography and habitat use of baleen whales, and conservation efforts must account for these impacts to be effective. However, knowledge of baleen whale climate responses is lacking, and current survey effort is insufficient to capture changes in migration and habitat use for many species. Due to their unique combination of ecological and life history characteristics, baleen whales are particularly vulnerable to climate change and their climate responses should be expected to differ fundamentally from those of other marine consumers. These characteristics include the need for both large quantities and high densities of prey, the need to accumulate large energy reserves seasonally, as well as highly migratory movements and the reliance on high-latitude foraging areas with narrow seasonal windows in resource availability. Climate responses in baleen whales may involve abrupt changes in foraging habitat in contrast to more gradual poleward shifts observed in other species, changes in the timing, extent or tendency for migration, and changes in energy accumulation or fitness. Recognizing that climate impacts may differ from other species is critical to measuring and anticipating changes to baleen whale populations in the face of ongoing climate change, and to effectively managing their populations in the future. North Atlantic right whales (Eubalena glacialis), arguably the best studied baleen whale species at a population scale, exemplify expectations for baleen whale climate responses and the implications for future management and conservation. Right whales have shown abrupt changes to traditional patterns of habitat use and migratory behavior, with major implications for the effectiveness of existing protections. Understanding and detecting baleen whale climate responses and effectively guiding management in the face of ongoing change will require increased survey effort and novel methods to survey remote habitats; improved knowledge of mechanisms of prey aggregation and climate impacts on these processes; and continued development and refinement of mechanistic models and dynamic management strategies.
