Search Results (19,801)

Fissure swarms and dike swarms in Iceland constitute the main parts of volcanic systems that are 40–150 km long, 5–20 km wide, extend to depths of 10–20 km, and contain 2 × 10¹⁴ outcrop-scale (≥0.1 m) and 10^22–23 down to grain-scale (≥1 mm) fractures, suggesting that statistical physics is an appropriate method of analysis. Length-size distributions of 565 outcrop-scale Holocene fissures (tension fractures and normal faults) and 1041 Neogene dikes show good to excellent fits with negative power laws and exponential laws. Here, the Helmholtz free energy is used to represent the energy supplied to the swarms and to derive the Gibbs–Shannon entropy formula. The calculated entropies of 12 sets and subsets of fissures and 3 sets and subsets of dikes all show strong positive correlations with sets/subsets length ranges and scaling exponents. Statistical physics considerations suggest that, at a given time, the probability of the overall state of stress in a crustal segment being heterogeneous is much greater than the state of stress being homogeneous and favourable to the propagation of a fissure or a dike. In a heterogeneous stress field, most fissures/dikes become arrested after a short propagation—which is a formal explanation of the observed statistical size-length distributions. As the size of the stress-homogenised rock volume increases larger fissures/dikes can form, increasing the length range of the distribution (and its entropy) which may, potentially, transform from an exponential distribution into a power-law distribution. Full article

This study presents the scientific and methodological foundation of Spain’s first national framework for the ethical management of community cat populations: the Action Plan for the Management of Community Cat Colonies (PACF), launched in 2025 under the mandate of Law 7/2023. This pioneering legislation introduces a standardized, nationwide obligation for trap–neuter–return (TNR)-based management of free-roaming cats, defined as animals living freely, territorially attached, and with limited socialization toward humans. The PACF aims to support municipalities in implementing this mandate through evidence-based strategies that integrate animal welfare, biodiversity protection, and public health objectives. Using standardized data submitted by 1128 municipalities (13.9% of Spain’s total), we estimated a baseline population of 1.81 million community cats distributed across 125,000 colonies. These data were stratified by municipal population size and applied to national census figures to generate a model-ready demographic structure. We then implemented a stochastic simulation using Vortex software to project long-term population dynamics over a 25-year horizon. The model integrated eight demographic–environmental scenarios defined by a combination of urban–rural classification and ecological reproductive potential based on photoperiod and winter temperature. Parameters included reproductive output, mortality, sterilization coverage, abandonment and adoption rates, stochastic catastrophic events, and territorial carrying capacity. Under current sterilization rates (~20%), our projections indicate that Spain’s community cat population could surpass 5 million individuals by 2050, saturating ecological and social thresholds within a decade. In contrast, a differentiated sterilization strategy aligned with territorial reproductive intensity (50% in most areas, 60–70% in high-pressure zones) achieves population stabilization by 2030 at approximately 1.5 million cats, followed by a gradual long-term decline. This scenario prioritizes feasibility while substantially reducing reproductive output, particularly in rural and high-intensity contexts. The PACF combines stratified demographic modeling with spatial sensitivity, offering a flexible framework adaptable to local conditions. It incorporates One Health principles and introduces tools for adaptive management, including digital monitoring platforms and standardized welfare protocols. While ecological impacts were not directly assessed, the proposed demographic stabilization is designed to mitigate population-driven risks to biodiversity and public health without relying on lethal control. By integrating legal mandates, stratified modeling, and realistic intervention goals, this study outlines a replicable and scalable framework for coordinated action across administrative levels. It exemplifies how national policy can be operationalized through data-driven, territorially sensitive planning tools. The findings support the strategic deployment of TNR-based programs across diverse municipal contexts, providing a model for other countries seeking to align animal welfare policy with ecological planning under a multi-level governance perspective. Full article

Background: Current food systems contribute significantly to poor public health and environmental degradation. With increasing rates of chronic disease and undernutrition globally and in the United States of America (U.S.), transforming food systems toward sustainability is a critical public health priority. Objectives: This narrative review aimed to summarize U.S. policies from the past decade relevant to sustainable food systems, focusing on four domains—availability, accessibility, affordability, and desirability—proposed by the 22nd Annual Harvard Nutrition Obesity Symposium. Methods: Systematic searches were conducted using MEDLINE (PubMed), Scopus, U.S. Congress websites, and Google searches. Studies and policies published between 2013 and 2023 that addressed at least one of the four domains were included. Policies were reviewed according to their alignment with the policy lifecycle framework, encompassing formulation through implementation. Results: A review of the final 632 articles explained that, despite growing interest in sustainable food systems, there is a lack of comprehensive U.S. policies that address the four domains in an integrated manner. Most initiatives were limited in scope, often school-based, and not explicitly sustainability-focused. Food availability and accessibility policies exist but remain fragmented, while affordability and desirability domains are severely underrepresented. Few laws or bills have been enacted or evaluated for population-level or environmental outcomes. Conclusions: Transforming U.S. food systems requires more robust evidence-based policy development and evaluation. There is an urgent need for integrated multisectoral policy frameworks to ensure health, equity, and sustainability across all food system domains. Full article

Existing studies have shown that placing 3D-printed lattices in cement matrices can effectively improve the ductility of cement-based composites. However, the influence of thermal fatigue effect on the mechanical properties of 3D-printed lattice-reinforced cement-based composites during service remains to be studied. In this paper, cement-based materials without lattices were used as the control group, and the uniaxial compressive mechanical properties of 3D-printed lattice-reinforced cement-based composites after thermal fatigue treatment under a temperature difference of 60 °C were tested. The number of thermal fatigue cycles was set to 45, 90, and 145 times, respectively. During the test, two non-destructive testing technologies, AE and DIC, were used to analyze the strength degradation and deformation law of 3D-printed lattice-reinforced cement-based composites with the increase in cycles. AE adopted the threshold triggering mode, and the channel threshold was 100 mv. The experiment showed that the compressive strength of the control group after 45, 90, and 145 thermal cycles decreased to 72.47% and 49.44% of that of the specimen after 45 thermal cycles, respectively. The strength of RO lattices decreased to 91.07% and 82.14% of that of the specimen after 45 thermal cycles, respectively, while the strength of SO lattices decreased to 83.27% and 77.96% of that of the specimen after 45 thermal cycles, respectively. The compressive strengths of the two types of lattices were higher than that of the control group after three cycles, indicating that 3D-printed lattices can effectively mitigate the influence of environmental thermal fatigue on the mechanical properties of cement-based materials. Full article

The strength mobilisation framework was adopted for the first time to describe the stress–strain responses for three different types of sands, including a total of 30 published drained triaxial tests—25 for Karlsruhe Fine Sand, 2 for Ottawa sands and 3 for Fontainebleau sand, under confining pressures ranging from 50 to 400 kPa. The peak shear strength ${\tau }_{peak}$ obtained from drained triaxial shearing of these sands was used to normalise shear stress. Shear strains normalised at peak strength ${\gamma }_{peak}$ and at half peak of shear strength ${\gamma }_{M=2}$ were taken as the normalised reference strains, and the results were compared. Power–law functions were then derived when the mobilised strength was between $0.2{\tau }_{peak}$ and $0.8{\tau }_{peak}$. Exponents of the power–law functions of these sands were found to be lower than in the published undrained shearing data of clays. Using ${\gamma }_{M=2}$ as the reference strain shows a slightly better power–law correlation than using ${\gamma }_{peak}$. Linear relationships between the reference strains and variables, such as relative density, relative dilatancy index, and dilatancy, are identified. Full article

The impact mechanism of long-term creep in gas-containing coal on coal and gas outbursts has not been fully elucidated and remains insufficiently understood for the purpose of disaster engineering control. This investigation conducted triaxial creep experiments on raw coal specimens under controlled confining pressures, axial stresses, and gas pressures. Through systematic analysis of coal’s physical responses across different loading conditions, we developed and validated a novel creep damage constitutive model for gas-saturated coal through laboratory data calibration. The key findings reveal three characteristic creep regimes: (1) a decelerating phase dominates under low stress conditions, (2) progressive transitions to combined decelerating–steady-state creep with increasing stress, and (3) triphasic decelerating–steady–accelerating behavior at critical stress levels. Comparative analysis shows that gas-free specimens exhibit lower cumulative strain than the 0.5 MPa gas-saturated counterparts, with gas presence accelerating creep progression and reducing the time to failure. Measured creep rates demonstrate stress-dependent behavior: primary creep progresses at 0.002–0.011%/min, decaying exponentially to secondary creep rates below 0.001%/min. Steady-state creep rates follow a power law relationship when subject to deviatoric stress (R² = 0.96). Through the integration of Burgers viscoelastic model with the effective stress principle for porous media, we propose an enhanced constitutive model, incorporating gas adsorption-induced dilatational stresses. This advancement provides a theoretical foundation for predicting time-dependent deformation in deep coal reservoirs and informs monitoring strategies concerning gas-bearing strata stability. This study contributes to the theoretical understanding and engineering monitoring of creep behavior in deep coal rocks. Full article

Incineration at sea is a significant source of marine pollution, threatening biodiversity and public health. Although Peru ratified the 1996 London Protocol in 2018, key deficiencies persist in its domestic legal framework, particularly the absence of clear and internationally aligned definitions for “incineration” and “incinerator.” These gaps hinder effective enforcement by the National Maritime Authority (NMA-DICAPI) and limit regulatory compliance with international obligations. This study analyzes Peru’s current legislation in light of the London Protocol and includes a comparative overview of regional regulatory approaches in Latin America. Based on this analysis, the study identifies regulatory inconsistencies that compromise environmental protection and proposes three key legal reforms: (1) refining the definition of “incineration” to reflect international standards; (2) formally incorporating a definition for “incinerator”; and (3) establishing specific administrative and economic sanctions for related infractions. Through comparative analysis with Mexico and Colombia’s approaches, we propose targeted amendments including refined definitions aligned with IMO standards and explicit administrative/economic sanctions. Implementing these recommendations would enhance Peru’s legal clarity, enforcement capacity, and compliance with international maritime law, reinforcing its role as a responsible actor in marine environmental governance. Full article

Central Environmental Protection Inspection (CEPI) is a major step in China’s environmental vertical supervision reform. With the multi-period Difference-in-Differences method, we assess the impact of CEPI on enterprise green transformation. In addition, we further explore the impact of enterprise environmental self-discipline. The results show that CEPI significantly promotes enterprise green transformation, and this effect on governance is further strengthened by environmental self-discipline. The synergistic governance effect of compound environmental regulation is pronounced, particularly in enterprises lacking government–enterprise relationships and in areas covered by CEPI “look back” initiatives and where local governments rigorously enforce environmental laws. The mechanism analysis reveals that CEPI mainly promotes enterprise green transformation by improving executive green cognition, boosting investment in environmental protection, and enhancing green innovation efficiency. This study provides a fresh perspective on analyzing the governance impact of CEPI and provides valuable insights for improving multi-collaborative environmental governance systems. Full article

To enhance the reliability of electric propulsion in electric aircraft and address power interruptions caused by current sensor failures, this study proposes a current sensorless fault-tolerant control strategy for permanent magnet synchronous motors (PMSMs) based on a long short-term memory (LSTM) network. First, a hierarchical architecture is constructed to fuse multi-phase electrical signals in the fault diagnosis layer (sliding mode observer). A symbolic function for the reaching law observer is designed based on Lyapunov theory, in order to generate current predictions for fault diagnosis. Second, when a fault occurs, the system switches to the LSTM reconstruction layer. Finally, gating units are used to model nonlinear dynamics to achieve direct mapping of speed/position to phase current. Verification using a physical prototype shows that the proposed method can complete mode switching within 10 ms after a sensor failure, which is 80% faster than EKF, and its speed error is less than 2.5%, fully meeting the high speed error requirements of electric aircraft propulsion systems (i.e., ≤3%). The current reconstruction RMSE is reduced by more than 50% compared with that of the EKF, which ensures continuous and reliable control while maintaining the stable operation of the motor and realizing rapid switching. The intelligent algorithm and sliding mode control fusion strategy meet the requirements of high real-time performance and provide a highly reliable fault-tolerant scheme for electric aircraft propulsion. Full article

The proliferation of biometric technology across various domains including user identification, financial services, healthcare, security, law enforcement, and border control introduces convenience in user identity verification while necessitating robust protection mechanisms for sensitive biometric data. While chaos-based encryption systems offer promising solutions, many existing chaos-based encryption schemes exhibit inherent shortcomings including deterministic randomness and constrained key spaces, often failing to balance security robustness with computational efficiency. To address this, we propose a novel dual-layer cryptographic framework leveraging a four-dimensional (4D) Qi hyperchaotic system for protecting biometric templates and facilitating secure feature matching operations. The framework implements a two-tier encryption mechanism where each layer independently utilizes a Qi hyperchaotic system to generate unique encryption parameters, ensuring template-specific encryption patterns that enhance resistance against chosen-plaintext attacks. The framework performs dimensional normalization of input biometric templates, followed by image pixel shuffling to permutate pixel positions before applying dual-key encryption using the Qi hyperchaotic system and XOR diffusion operations. Templates remain encrypted in storage, with decryption occurring only during authentication processes, ensuring continuous security while enabling biometric verification. The proposed system’s framework demonstrates exceptional randomness properties, validated through comprehensive NIST Statistical Test Suite analysis, achieving statistical significance across all 15 tests with p-values consistently above 0.01 threshold. Comprehensive security analysis reveals outstanding metrics: entropy values exceeding 7.99 bits, a key space of ${10}^{320}$, negligible correlation coefficients (<${10}^{-2}$), and robust differential attack resistance with an NPCR of 99.60% and a UACI of 33.45%. Empirical evaluation, on standard CASIA Face and Iris databases, demonstrates practical computational efficiency, achieving average encryption times of 0.50913s per user template for 256 × 256 images. Comparative analysis against other state-of-the-art encryption schemes verifies the effectiveness and reliability of the proposed scheme and demonstrates our framework’s superior performance in both security metrics and computational efficiency. Our findings contribute to the advancement of biometric template protection methodologies, offering a balanced performance between security robustness and operational efficiency required in real-world deployment scenarios. Full article

Based on a comprehensive review of the current research status of ecological compensation both domestically and internationally, combined with field survey data, this study delves into the issue of multi-stakeholder participation in the ecological compensation mechanisms of the Xin’an River Basin. This research reveals that the joint participation of multiple stakeholders is crucial to achieving the goals of ecological compensation in river basins. The government plays a significant role in macro-guidance, financial support, policy guarantees, supervision, and management. It promotes the comprehensive implementation of ecological environmental protection by formulating relevant laws and regulations, guiding the public to participate in ecological conservation, and supervising and punishing pollution behaviors. The public, serving as the main force, forms strong awareness and behavioral habits of ecological protection through active participation in environmental protection, monitoring, and feedback. As participants, enterprises contribute to industrial transformation and green development by improving resource utilization efficiency, reducing pollution emissions, promoting green industries, and participating in ecological restoration projects. Scientific research institutions, as technology enablers, have effectively enhanced governance efficiency through technological research and innovation, ecosystem value accounting to provide decision-making support, and public education. Social organizations, as facilitators, have injected vitality and innovation into watershed governance by extensively mobilizing social forces and building multi-party collaboration platforms. Communities, as supporters, have transformed ecological value into economic benefits by developing characteristic industries such as eco-agriculture and eco-tourism. Based on the above findings, further recommendations are proposed to mobilize the enthusiasm of upstream communities and encourage their participation in ecological compensation, promote the market-oriented operation of ecological compensation mechanisms, strengthen cross-regional cooperation to establish joint mechanisms, enhance supervision and evaluation, and establish a sound benefit-sharing mechanism. These recommendations provide theoretical support and practical references for ecological compensation worldwide. Full article

Fast prediction of beam quality in SBS pulse compression for high-repetition-rate operation is urgently important for SBS experimental parameter acquisition. In this study, a fast computational prediction model for SBS beam profiles is developed using a convolutional neural network (CNN) method, which is trained and validated using experimental data from SBS pulse compression experiments. The CNN method can predict beam spot images for experimental conditions in the range of 100–500 Hz repetition rates and 5–40 mJ injection energy. The proposed CNN-based SBS beam profile prediction model has a fast convergence of the loss function and an average error of 15% with respect to the experimental results, indicating a high accuracy of the model. The CNN-based prediction model achieves an average error of 11.8% for beam profile prediction across various experimental conditions, demonstrating its potential for SBS beam profile characterization. The CNN method could provide a fast means for predicting the characteristic law of the beam intensity distribution in high-repetition-rate SBS pulse compression systems. Full article

Livestock, poultry, and fisheries play an important economic role in Pakistan’s animal industry. The pet industry is also emerging and contributing to the country’s economy and people’s emotional well-being. This review provides insight into the current challenges and future directions of the animal industry in Pakistan. Livestock, poultry, and fisheries provide an economically beneficial source of milk, meat, and eggs; however, they face challenges such as disease outbreaks, antimicrobial resistance, climate change, natural disasters, and a lack of proper policies. Likewise, humans benefit from companion animals that provide emotional attachment. Moreover, the pet food market has also shown potential growth, contributing to the country’s economy. Due to the close association between animals and humans, both are at risk for infectious disease transmission. Challenges such as the lack of strong animal welfare laws and the increasing number of stray dogs and cats threaten human safety and that of other animals. We highlight current problems and additional approaches to the management of livestock, poultry, fisheries, and pets, which need to be addressed to further advance the animal industry in Pakistan. Full article

Nanoplastics (NPs), the tiniest and one of the most problematic fractions of plastic pollution, present dangers because of their size, reactivity, and ecosystem interactions. This review highlights the distinct characteristics, sources, routes, and ecological effects of NPs, a substantial subgroup of plastic pollution. With a focus on their ecological and toxicological implications, this review highlights the unique qualities of NPs and their functions in wastewater and urban runoff systems. The analysis of NPs’ entry points into terrestrial, aquatic, and atmospheric ecosystems reveals difficulties with detection and quantification that make monitoring more difficult. Filtration technologies, adsorption-based techniques, and membrane bioreactors are examples of advanced technical solutions emphasized as efficient NP mitigation measures that can integrated into current infrastructure. Environmental effects are examined, including toxicological hazards to organisms in freshwater, terrestrial, and marine environments, bioaccumulation, and biomagnification. This analysis emphasizes the serious ecological problems that NPs present and the necessity of using civil and environmental engineering techniques to improve detection techniques, enact stronger laws, and encourage public participation. Full article

This study examines the energy behavior of a strengthening system consisting of a Fiber Reinforced Polymer (FRP) plate bonded to a rigid substrate and subjected to tensile loading, where the adhesive interface is governed by a bilinear bond–slip law with a vertical descending branch. The investigation focuses on the interaction between the elastic energy stored in the FRP and the adhesive interface, as well as the characteristic lengths that control the debonding process. Analytical expressions for the strain energy stored in both the FRP plate and the adhesive interface are derived, enabling the identification and evaluation of two critical characteristic lengths as the bond stress at the loaded end approaches its maximum value $l_c$, at which the elastic energies of the FRP and the adhesive interface converge, signaling energy saturation; and $l_{max}$, where the adhesive interface attains its peak energy absorption. Upon reaching the energy saturation state, the system undergoes failure through the sudden and complete debonding of the FRP from the substrate. The onset of unstable debonding is rigorously analyzed in terms of the first and second derivatives of the total potential energy with respect to the bond length. It is further demonstrated that abrupt debonding may also occur in cases where the length exceeds $l_c$ when the bond stress reaches its maximum, and the bond–slip law is characterized by a vertical branch. The findings provide significant insights into the energy balance and stability criteria governing the debonding failure mode in FRP-strengthened structures, highlighting the pivotal role of characteristic lengths in predicting both structural performance and failure mechanisms. Full article