Search Results (325)

We present a fast time-domain simulator for optical cavities capable of reproducing non-linear dynamical regimes arising from the ring-down effect during resonance crossings at high mirror velocities or from abrupt changes of the input field. The model is based on a recursive formulation of the intracavity electric field as a sum over round trips, preserving the cavity memory while maintaining high computational efficiency. The simulator is designed to achieve three main goals. First, the boundary conditions of the cavity can be modified at each simulation step, allowing arbitrary time-dependent variations of both mirror positions and input electric field during the simulation run. Second, the sampling frequency can be flexibly chosen by the user; however, it is internally adjusted before effectively executing the simulation to remain consistent with the cavity round-trip structure. Finally, high computational efficiency was obtained by avoiding the repeated evaluation of the full electric field history. The framework is validated through comparison with experimental data from the Virgo interferometer during a mechanical excitation experiment, showing good agreement in non-adiabatic regimes. Due to its efficiency and flexibility, the oreonspy simulator provides a versatile tool for time-domain studies of optical resonators and future applications in real-time control and reinforcement-learning-based lock acquisition. Full article

Introduction: Marine recreational fishing (MRF) is a socially, economically, and ecologically important activity. However, the absence of systematic monitoring and research in Portugal has limited a comprehensive understanding of the sector and its broader implications. Addressing these gaps is essential to support evidence-based and adaptive recreational fisheries management. Objective: This work aimed to improve understanding of marine recreational fishing in Portugal by integrating social and biological perspectives across national, regional, and local scales. Methodology: A multidisciplinary approach was applied. At the national scale, online questionnaire data were combined with licencing information and regional effort estimates to quantify fishing effort, catches, release rates, catch composition, and direct trip expenditures. The same survey framework was also used to identify recreational fisher profiles based on motivations, behaviours, fishing practices, and attitudes toward management. At the local scale, shore angling surveys conducted before the implementation of the Natural Marine Park of the Algarve Reef were used to estimate fishing activity and establish a baseline for future monitoring. From a biological perspective, field-based catch-and-release experiments were conducted to assess post-release mortality and physiological disturbance, using indicators such as mortality, condition, capture and handling variables, and blood biomarkers of stress and recovery. Results: The national estimates documented substantial fishing effort, catches, and direct expenditure, confirming the relevance of MRF in Portugal at both ecological and socio-economic levels. Portuguese recreational fishers were also shown to be heterogeneous in their motivations, behaviours, and practices, reinforcing the need for management approaches that reflect this diversity. At the local scale, shore angling estimates from the Natural Marine Park of the Algarve Reef provided an important pre-protection baseline for the now established Marine Protected Area, enabling future comparisons and long-term assessment of management effects. Biological experiments showed that recreational fishing can generate measurable physiological disturbance in fish, with post-release condition influenced by capture and handling factors. Among the variables examined, hook location emerged as particularly important, with deep-hooked fish showing greater impairment and higher mortality risk. Conclusions: Together, these findings show that improving recreational fisheries management in Portugal requires integrating social patterns, fishery magnitude, and biological responses to capture and release. Long-term monitoring programmes, combined with management approaches adapted to different fisher profiles and fishing contexts, are essential to support more effective and sustainable recreational fisheries governance. Full article

This paper investigates the feasibility of 3D self-localization and tracking using chipless radio frequency identification (RFID) tags operating in the terahertz (THz) frequency band. The primary objective is to achieve sub-millimeter (sub-mm) localization and tracking accuracy while minimizing reliance on external infrastructure. To this end, a hybrid localization framework is proposed that jointly exploits round-trip time-of-flight (RToF) and angle-of-arrival (AoA) measurements to enhance localization performance. Although near-field propagation effects are inherently significant in the considered THz operating regime, a simplified far-field approximation is adopted to facilitate tractable system modeling and analytical development. The proposed framework is further extended to dynamic scenarios through an extended Kalman filter (EKF)-based tracking algorithm, which incorporates temporal state evolution to improve estimation robustness under noisy measurements. Furthermore, the Cramér–Rao lower bound (CRLB) for the hybrid RToF-AoA system is derived to establish the fundamental limits of localization accuracy under varying system configurations and measurement conditions. Simulation results demonstrate that the proposed approach is capable of achieving sub-mm localization and tracking accuracy with a highly constrained anchor infrastructure, including operation with a single anchor in the considered scenario. These findings highlight the potential of THz chipless RFID technology as a promising enabling solution for next-generation high-accuracy localization and tracking applications. Full article

A multiphase high-strength steel austempered at 260 °C for 24 h was investigated by quasi-in-situ tensile characterization and EBSD-based crystal plasticity finite element modeling. The experimental observations reveal that local plastic deformation is strongly heterogeneous: von Mises strain concentrates preferentially near bainitic-ferrite packets, phase boundaries, and retained-austenite/martensite–austenite regions, whereas blocky retained austenite contributes to strain accommodation at the early deformation stage. To quantify the underlying stress–strain partitioning, a quasi-two-dimensional representative volume element was reconstructed from EBSD data and implemented in ABAQUS through a user-defined material subroutine. The model contained the real grain morphology, phase distribution, and crystal orientation information of the 24 h austempered specimen. A rate-dependent crystal plasticity constitutive framework with BCC matrix, FCC retained austenite, and transformed martensite branches was calibrated against the macroscopic tensile curve. The simulated tensile response agrees well with the experimental curve before macroscopic instability, and the predicted local fields are consistent with the quasi-in-situ strain maps. The results show that local plastic strain first accumulates in M/A-related regions and phase-boundary-neighboring zones, while high Mises stress migrates dynamically with slip activity and stress-induced martensitic transformation. Retained-austenite transformation increases the local load-bearing capacity, modifies interphase load transfer, and delays the direct linkage of strain-localization bands. The present work clarifies the coupling among retained-austenite stability, TRIP-assisted load redistribution, and microstructural strain partitioning in multiphase high-strength steel, providing a mesoscale basis for microstructure-guided strength–ductility optimization. Full article

To scientifically explore the vehicle capacity characteristics of circular earthwork transportation routes in water conservancy projects, this paper takes the second-phase project of the Huaihe River Sea Entrance Channel as the research background. Key influencing factors such as road conditions, vehicle performance parameters, safe car-following distance, and earthwork loading–unloading duration are comprehensively considered, and a cellular automaton simulation model is constructed. Horizontal comparative verification is carried out with the Intelligent Driver Model, System Dynamics model, and field measured data to verify model accuracy. The results reveal that the cellular automaton (CA) model yields a total vehicle transport trip count of 606, with a MAPE of 0.66% when compared against the field-measured average of 602 trips. The simulated average travel speed reaches 16.71 km/h, corresponding to a MAPE of 2.89% relative to the field measurement of 16.24 km/h. The error metrics of these two indicators are markedly lower than those derived from alternative models. Due to differences in modeling paradigms and applicable mechanisms, the three models exhibit distinct characteristics in simulation performance. Among them, the cellular automaton model is more suitable for the circular earthwork transportation scenario of this study, which can accurately reflect the coupling characteristics of microscopic traffic behaviors such as multi-route confluence and node queuing, and has high consistency with actual engineering operation. Sensitivity analysis indicates that improving earth loading efficiency and reasonably arranging excavator quantity can significantly enhance the overall transportation efficiency. The modeling ideas and simulation analysis method adopted in this paper are not only applicable to the specific engineering scenario, but also can be extended to similar water conservancy earthwork transportation and large-scale engineering logistics transportation fields. It can provide theoretical basis and engineering reference for earthwork scheduling optimization and quantitative calculation of traffic capacity in water conservancy projects. Full article

Electrification of public transit is central to sustainable urban development, yet it introduces passenger exposure to extremely low-frequency magnetic fields (ELF-MFs), which the International Agency for Research on Cancer (IARC) classifies as possibly carcinogenic to humans (Group 2B). This study presents a systematic cross-platform comparison of ELF-MF exposure in direct current (DC) light rail and alternating current (AC) heavy rail systems operating under a single national regulatory framework. A total of 9100 continuous measurements were collected across 28 trips on the Tel Aviv Red Line light rail transit (1500 V DC) and the Israel Railways Tel Aviv–Binyamina corridor (25 kV, 50 Hz AC) during 23–26 November 2025, using calibrated Tenmars TM-192D gaussmeters. Mean passenger seat magnetic flux density was 0.226 ± 0.147 µT (2.26 ± 1.47 mG) for the DC system and 0.900 ± 0.606 µT (9.00 ± 6.06 mG) for the AC system. The difference was highly significant (Welch’s t = −73.06, p < 0.001). DC light rail exposure remained consistently below Israel’s precautionary 0.4 µT (4 mG) threshold for continuous public exposure, whereas AC heavy rail mean levels exceeded this threshold in every monitored trip while remaining far below ICNIRP general public reference levels. These findings highlight a “Green Dilemma” in sustainable transport policy: the environmental benefits of rail electrification must be balanced with prudent electromagnetic exposure management in jurisdictions applying strict precautionary limits. Full article

According to the International Association for Suicide Prevention (IASP), over one in every 100 deaths (1.3%) in 2019 was the result of suicide, yet suicide is a highly sensitive issue in the media and often a taboo. The field of communication research has very early recognized the relevance of coverage of suicide. One of the first manuals on journalistic work in 1925 elaborated on newsworthiness of suicide reporting. This paper draws on experiences of journalists who covered suicide cases during multiple crises. There is evidence that an interview is the most appropriate practice to research sensitive topics; thus, expert interviews and episodically ethnographic interviews inform this study. Additional data was collected for analysis during (participatory) observations. The presented article is an outcome of 29 interviews with journalists and mental health professionals in Greece, Spain and Bulgaria. In total, 36 h of interviews and 20 observation protocols were collected during 8 field trips and 5 weeks in total in the field. Most of the data refers to the financial crisis of 2015 and 2016—a period when suicide rates significantly increased. However, selected interviewees were interviewed again after 7–8 years during the post-pandemic time, brutal wars and the substantial cost of living crisis. Journalists who usually give a voice and platform to suicide survivors speak their own perspective and evaluate the impact it had on their mental health and well-being. Full article

Ensuring accessibility in alpine ski areas remains a critical challenge for social sustainability and inclusive tourism because physical, seasonal and organisational constraints interact across the visitor experience. This paper reframes accessibility as a dynamic and relational landscape attribute and proposes a flow-chain framework for assessing accessibility as a sequence of interdependent phases, from pre-trip information to arrival, lift access, slope use, rest and return. Developed within the Ski-Ability project in the ArgeAlp working community, the study draws on exploratory field observations, stakeholder engagement and co-design activities conducted across seven Alpine pilot resorts. The pilot resorts are not treated as a statistically representative sample, but as field cases used to understand current operational conditions in a context where academic literature, technical standards and regulatory guidance specific to accessible ski areas remain limited. The framework is operationalised through a qualitative toolkit based on Basic, Comfort and Plus levels, priority categories and non-compensatory decision rules. The results provide methodological validation and practical guidance rather than quantitative benchmarking. They show that accessibility in alpine ski areas depends on the continuity of routes, services, information and assistance, and on coordination among multiple actors. The paper contributes to social sustainability research by linking Universal Design, accessible tourism and mountain governance within a transferable, process-oriented assessment model. Full article

This exploratory study assessed the vehicle- and route-dependent response of five multipoint injection passenger vehicles to two commercial fuel additives marketed as octane-related gasoline additives under real-world high-altitude driving conditions in Quito, Ecuador. The tests were conducted on one urban route and one rural/peripheral route using base gasoline with a nominal octane index of RON 85, RON 85 gasoline with Additive A, and RON 85 gasoline with Additive B. Fuel economy and CO₂-related indicators were obtained through the OBD-II port using the Torque Pro application; therefore, the reported values were interpreted as electronic control unit-based estimates rather than direct gravimetric fuel consumption or laboratory emissions measurements. The revised analysis used OBD-derived trip-average fuel economy as the primary response variable. The mixed-effects model showed a significant effect of route on fuel economy (p < 0.001) and a significant fuel condition × route interaction (p = 0.0089), while the main effect of fuel condition was not statistically significant (p = 0.0699). Additive B increased the mean OBD-derived trip-average fuel economy on the urban route from 11.56 to 12.60 km·L⁻¹, but reduced it on the rural route from 13.46 to 12.65 km·L⁻¹. At the vehicle level, the previously extreme Vehicle 3 response was revised to a more plausible increase from 11.03 to 13.64 km·L⁻¹ (+23.68%) when trip-average fuel economy was used. Since the actual RON/MON values and physicochemical properties of the final fuel blends were not experimentally measured, the observed responses cannot be attributed exclusively to octane number enhancement. Overall, the findings indicate that commercial additive performance was vehicle- and route-dependent rather than universally beneficial. This field-based assessment supports evidence-informed decision-making for sustainable mobility and aligns with SDG 16 and SDG 17 through transparent technical evaluation and academic collaboration. Full article

Degraded network conditions and intermittent disconnections can impair solar greenhouse Internet of Things (IoT) systems by delaying cloud-to-field control, generating burst traffic after reconnection, and disrupting alarm feedback loops. This paper proposes a resilient end–edge–cloud collaborative framework for maintaining control continuity and closed-loop alarm reliability under unstable edge–cloud communication. The framework evaluates network quality using round-trip time, packet loss rate, and consecutive no-response duration, and combines hysteresis-based state switching, control leases, edge takeover, differential backfill, and locally persistent alarm-state synchronization. During disconnection, the edge gateway uses the latest valid configuration to execute fallback local control; after reconnection, high-priority events are uploaded first through a hierarchically rate-limited recovery strategy. In the scripted simulation experiments, the proposed method reduced peak backfill throughput from 2.16 ± 0.06 MB/s to 0.69 ± 0.01 MB/s, shortened high-priority event completion time from 17.3 ± 2.7 s to 2.0 ± 0.7 s, and increased the acknowledgment success rate at 20% packet loss from 76.5 ± 2.2% to 98.4 ± 0.8%. It also reduced the maximum temperature deviation during disconnection from 7.20 °C to 3.50 °C. These results suggest that the proposed framework can improve control continuity and alarm-loop completeness under the specified simulation settings. A supplementary trace-driven recovery evaluation using public 5G testbed measurements showed a similar qualitative trend. Broader validation with field-deployed greenhouse IoT platforms or hardware-in-the-loop testbeds is still needed. Full article

Enhancing spatial orientation and map-reading skills is a cornerstone of geography education, yet the comparative efficacy of physical versus virtual reality learning environments (VRLEs) remains a subject of ongoing debate. This study evaluates the development of navigational competencies through a counterbalanced crossover experimental design involving 20 geography and geography teacher major students. Participants performed standardized spatial tasks, including bearing calculation and distance estimation, in both the volcanic landscape of the Tapolca Basin, Hungary, and its smartphone-based 360-degree virtual reality (VR) counterpart. To assess longitudinal retention and cross-modal transfer, a three-month interval was maintained between the two learning phases, supported by a robust pre-test/post-test framework. Results indicate that while both environments are susceptible to spatial distortions driven by the visual dominance of physiographic landmarks, VR-based training effectively scaffolds the cognitive frameworks required for real-world navigation. The findings confirm that spatial mental models acquired in a virtual setting possess significant cognitive resilience, as navigational accuracy was maintained over the three-month interval. In conclusion, this research justifies a hybrid pedagogical approach, where immersive digital simulations serve as a preparatory tool for physical fieldwork. The synergy of both modalities is essential for cultivating the resilient spatial intelligence required for professional geographic practice. Full article

Hybrid hydrogen energy storage systems are increasingly considered for renewable integration in rural and weak-grid contexts, yet much of the literature remains simulation-based, site-specific, or insufficiently explicit about control and operational performance. This paper examines a hybrid hydro–PV–battery–hydrogen system operated at the Agkistron Living Lab in Northern Greece and assesses the role of layered storage in renewable surplus valorization and resilience-oriented operation. This study combines a system architecture description, a supervisory energy management strategy based on Hybrid Automata, and analysis of field data under both grid-connected and intentional off-grid conditions. The installation integrates hydropower, photovoltaics, battery storage, alkaline electrolysis, hydrogen storage, and PEMFCs. The results show that during on-grid operation, the EMS prioritizes battery charging and then hydrogen production, enabling high renewable utilization and low curtailment while preparing reserves for outages. During a 48 h intentional islanding event, the battery and hydrogen pathway operated sequentially, achieving an autonomy index of 82%, compared with 36% for the battery-only benchmark. Although the hydrogen pathway showed lower round-trip efficiency than battery-only storage, it substantially extended off-grid autonomy and continuity of supply. The findings support hybrid battery–hydrogen storage as a transferable operating concept for rural systems where renewable surplus and resilience requirements coexist. Full article

This study investigates the educational impact of an industrial field visit on the learning experience of second-year pharmacy students at Qatar University. The visit, integrated within the Pharmaceutics II course (PHAR 310), was designed to complement theoretical instruction by providing exposure to real-world pharmaceutical manufacturing and quality control processes, particularly for parenteral dosage forms. A mixed-methods approach was employed using quantitative and qualitative data derived from post-visit questionnaires. Findings indicated that students reported positive perceptions of the experience, with the majority indicating improved understanding of key pharmaceutical manufacturing concepts and strong support for the inclusion of similar activities within the curriculum. Qualitative analysis further suggested that the visit facilitated contextualization of theoretical knowledge, enhanced engagement, and supported early professional awareness. While these findings suggest that structured industrial visits may serve as a valuable complementary educational strategy in pharmacy training, the results should be interpreted with caution due to the small sample size and single-institution design. Further research incorporating larger cohorts, objective learning assessments, and longitudinal evaluation is underway to better establish the educational impact of these interventions. Full article

In Coiled Tubing (CT) acoustic telemetry, the reliability of surface signal reception is severely challenged by the “contact dead zone” of traditional probes and complex nonstationary environmental noise. To address these issues, this paper proposes a hardware-software integrated solution for high-fidelity signal extraction. In terms of hardware, a novel pickup probe based on the micro-lever principle is developed. By utilizing a pivoted lever structure with an optimized arm ratio of 2.6 to 1 and a full pressure-balanced mechanism, the design physically overcomes the contact dead zone inherent in traditional pressure-compensating probes and effectively isolates low frequency common-mode interference through a lateral floating architecture. In terms of software, a joint denoising model combining Complete Ensemble Empirical Mode Decomposition with Adaptive Noise and wavelet thresholding is proposed. A cross-correlation coefficient criterion is introduced to adaptively screen intrinsic mode functions and eliminate residual fluid turbulence noise. Field experiments on a 1500 ft full-scale circulation loop demonstrate that the proposed probe improves the detection sensitivity of the radial breathing mode by approximately 20.6 dB compared to the baseline, while effectively eliminating stick-slip friction noise during dynamic tripping. Furthermore, the joint algorithm increases the Signal to noise Ratio by an additional 16.9 dB under typical pumping conditions of 0.5 bpm, with a normalized cross-correlation exceeding 0.96. These results verify that the proposed method effectively solves the bottleneck of weak signal detection in deep wells, providing robust technical support for CT telemetry operations. Full article

This study presents the first comprehensive soil gas survey across southern Uruguay’s H₂ prospective terranes. A pre-field trip selection was done on the basement rock nature, as well as vegetation anomalies in subcircular depressions and fault presence. The Neoproterozoic terrane, north of Punta del Este, and the Archean Rio de la Plata Craton, north of Montevideo, as well as along the suture zones between the two, were targeted. Our findings reveal substantial H₂ concentrations, significantly outperforming many established basins worldwide. The suture zones act as critical migration conduits for H₂ coming from a deeper structural level. Slightly abnormal helium signatures confirm an active, deep-sourced fluid system, particularly within the Sierra Ballena and Cordillera shear zones. The Archean Rio de la Plata Craton appears promising but has only been partially sampled and warrants further investigation. These results underscore the high potential of Uruguay as a new frontier for natural hydrogen exploration. Full article