Search Results (177)

Savanna systems are characterised by a community of large mammal herbivores with up to 30 species; coexistence is based on resource partitioning. In this paper we analyse the features of the landscape and plant structure which lead herbivores to use particular locations, a key to resource partitioning. The processes involved, top-down versus bottom-up, are well known for large species and small ones but not for medium-sized ones. We use two resident, medium-sized species, topi (Damaliscus lunatus jimela) and kongoni, (Alcelaphus buselaphus cokei) in the central woodlands of the Serengeti; selection of habitat by the residents is important for predator-prey interactions and for interactions among the grazers. Using Principal Component Analysis and Multiple Regression we develop highly predictive models which show that resource availability is the critical determinant of habitat selection in the dry season; and reduction in predation risk appears to be important in the wet season. These results show for the first time that habitat selection by the medium-sized herbivores is driven by different strategies in the two seasons. This contributes to understanding the processes involved in the dynamics of this globally important savanna system, a necessary foundation for management. Full article

Municipal solid waste (MSW) and refuse-derived fuel (RDF) incineration generate over 20 million tons of residues annually in the EU. These include bottom ash (IBA), fly ash (FA), and air pollution control residues (APCr), which pose significant environmental challenges due to their leaching potential and hazardous properties. While these residues contain valuable metals and reactive mineral phases suitable for carbonation or alkaline activation, chemical, techno-economic, and policy barriers have hindered the implementation of sustainable, full-scale management solutions. Accelerated carbonation technology (ACT) offers a promising approach to simultaneously sequester CO₂ and enhance residue stability. This review provides a comprehensive assessment of waste incineration residue carbonation, covering 227 documents ranging from laboratory studies to field applications. The analysis examines reactor designs and process layouts, with a detailed classification based on material characteristics, operating conditions, investigated parameters, and the resulting pollutant stabilization, CO₂ uptake, or product performance. In conclusion, carbonation-based approaches must be seamlessly integrated into broader waste management strategies, including metal recovery and material repurposing. Carbonation should be recognized not only as a CO₂ sequestration process, but also as a binding and stabilization strategy. The most critical barrier remains chemical: the persistent leaching of sulfates, chromium(VI), and antimony(V). We highlight what we refer to as the antimony problem, as this element can become mobilized by up to three orders of magnitude in leachate concentrations. The most pressing research gap hindering industrial deployment is the need to design stabilization approaches specifically tailored to critical anionic species, particularly Sb(V), Cr(VI), and SO₄²⁻. Full article

Horizontal wells have revolutionized hydrocarbon production by enhancing recovery efficiency and reducing environmental impact. This paper presents an enhanced Black Oil Model simulator, written in Visual Basic, for three-dimensional two-phase (oil and water) flow through porous media. Unlike most existing tools, this simulator is customized for horizontal well modeling and calibrated using extensive historical data from the South Rumaila Oilfield, Iraq. The simulator first achieves a strong match with historical pressure data (1954–2004) using vertical wells, with an average deviation of less than 5% from observed pressures, and is then applied to forecast the performance of hypothetical horizontal wells (2008–2011). The results validate the simulator’s reliability in estimating bottom-hole pressure (e.g., ±3% accuracy for HRU1 well) and water–oil ratios (e.g., WOR reduction of 15% when increasing horizontal well length from 1000 m to 2000 m). Notably, the simulator demonstrated that doubling the horizontal well length reduced WOR by 15% while increasing bottom-hole pressure by only 2%, highlighting the efficiency of longer wells in mitigating water encroachment. This work contributes to improved reservoir management by enabling efficient well placement strategies and optimizing extraction planning, thereby promoting both economic and resource-efficient hydrocarbon recovery. Full article

The construction of marine ranching is a crucial component of China’s Blue Granary strategy, yet the fragmented knowledge system in marine ranching equipment impedes intelligent management and operational efficiency. This study proposes the first knowledge graph (KG) framework tailored for marine ranching equipment, integrating hybrid ontology design, joint entity–relation extraction, and graph-based knowledge storage: (1) The limitations in existing KG are obtained through targeted questionnaires for diverse users and employees; (2) A domain ontology was constructed through a combination of the top-down and the bottom-up approach, defining seven key concepts and eight semantic relationships; (3) Semi-structured data from enterprises and standards, combined with unstructured data from the literature were systematically collected, cleaned via Scrapy and regular expression, and standardized into JSON format, forming a domain-specific corpus of 1456 annotated sentences; (4) A novel BERT-BiGRU-CRF model was developed, leveraging contextual embeddings from BERT, parameter-efficient sequence modeling via BiGRU (Bidirectional Gated Recurrent Unit), and label dependency optimization using CRF (Conditional Random Field). The TE + SE + R_i + BMESO tagging strategy was introduced to address multi-relation extraction challenges by linking theme entities to secondary entities; (5) The Neo4j-based KG encapsulated 2153 nodes and 3872 edges, enabling scalable visualization and dynamic updates. Experimental results demonstrated superior performance over BiLSTM-CRF and BERT-BiLSTM-CRF, achieving 86.58% precision, 77.82% recall, and 81.97% F1 score. This study not only proposes the first structured KG framework for marine ranching equipment but also offers a transferable methodology for vertical domain knowledge extraction. Full article

Global supply chains have faced unprecedented disruptions in recent years, ranging from the COVID-19 pandemic to geopolitical tensions and climate-induced shocks. These events have exposed structural vulnerabilities in operational models overly optimized for efficiency at the expense of resilience and sustainability. This conceptual paper proposes an integrated framework linking resilience enablers, post-pandemic operational strategies, and sustainability outcomes. Through a synthesis of the interdisciplinary literature across operations management, sustainability science, institutional theory, and organizational behavior, we develop typologies of operational responses—including agile, lean–green, circular, and decentralized models—and connect them to broader Sustainable Development Goals (SDGs). Drawing on systems thinking and the Triple Bottom Line framework, we present a conceptual model that outlines causal relationships between resilience drivers, adaptive operational strategies, and long-term sustainable performance. The paper further discusses policy implications for public and private sectors, offering insights for global sustainability governance. We conclude by outlining a research agenda to empirically test and refine the model through multi-method approaches. This study contributes to theory by reconceptualizing sustainable operations in the context of compound global disruptions and offers a normative direction for future scholarship and practice. Full article

Medium- and large-scale heat sinks are critical for thermal load management in high-performance systems. However, their high heat flux densities and limited space complicate cooling, leading to risks of overheating, performance degradation, or failure. This study employs the Cascaded Lattice Boltzmann Method (CLBM) to enhance their thermal performance. This numerical approach is known for being stable, accurate when dealing with complex boundaries, and efficient when computing in parallel. The numerical code was validated against a benchmark configuration and an experimental setup to ensure its reliability and accuracy. While previous studies have explored mixed convection in cavities or heat sinks, few have addressed configurations involving side air injection and boundary conditions periodicity in the transition-to-turbulent regime. This gap limits the understanding of realistic cooling strategies for compact systems. Focusing on mixed convection in the transition-to-turbulent regime, where buoyancy and forced convection interact, the study investigates the impact of Rayleigh number values ($5\times {10}^7$ to $5\times {10}^8$) and Reynolds number values (${10}^3$ to $3\times {10}^3$) on heat transfer. Simulations were conducted in a rectangular cavity with periodic boundary conditions on the vertical walls. Two heat sources are located on the bottom wall ($T_h$ = 50 °C). Two openings, one on each side of the two hot sources, force a jet of fresh air in from below. An opening at the level of the cavity ceiling’s axis of symmetry evacuates the hot air. Mixed convection drives the flow, exhibiting complex multicellular structures influenced by the control parameters. Calculating the average Nusselt number (Nu) across the surfaces of the heat sink reveals significant dependencies on the Reynolds number. The proposed correlation between Nu and Re, developed specifically for this configuration, fills the current gap and provides valuable insights for optimizing heat transfer efficiency in engineering applications. Full article

In open-pit mines, substantial amounts of dust are generated at various stages. Due to the long duration, repeated mechanical disturbance, and large volume of material handled during the shoveling and loading of blasting piles, this stage is recognized as one of the primary contributors to overall dust emissions in open-pit mining operations. The objective of this study is to investigate the spatial dispersion characteristics of dust at blasting piles and evaluate the influence of wind direction on dust migration and escape behavior. This study uses a full-scale numerical model to analyze the airflow and dust migration characteristics at blasting piles under different wind directions. Simulation results show that dust particles of different sizes exhibit distinct dispersion patterns: large particles settle near the source, medium particles migrate a moderate distance, and fine particles (PM2.5 and PM10) travel further and are more likely to escape from the pit. The leeward slope and pit bottom are identified as critical zones of dust accumulation and escape. Under both dump-side and stope-side wind conditions, respirable dust (d < 5 μm) accounts for more than 50% of the escaped particles, posing potential health risks to workers. These findings establish a scientific basis for targeted dust suppression strategies, supporting safer and more sustainable mine site management. Full article

The private healthcare sector in Romania, led by prominent players such as Medlife, Regina Maria, Medicover and Sanador, has become a cornerstone of the country’s healthcare system. However, achieving sustainability in this sector remains a challenge. This study evaluates sustainability practices in Romania’s private medical sector using the Triple Bottom Line (TBL) framework, comparing them to those of the EU, USA and Japan. Using statistical methods and benchmarking, we identify correlations between healthcare expenditures, financing schemes and sustainability metrics. A bibliographic review highlights global trends in sustainable healthcare management, including environmental, social and economic strategies and provides insights into the cost-effectiveness of green initiatives. Special focus is given to the role of technology in driving sustainability through innovations in telemedicine, digital health records and operational optimization. Using statistical methods (Pearson and Spearman correlation coefficients), we have performed an analysis of health expenditure data for EU countries, the USA and Japan. The dataset was extracted from the Organisation for Economic Co-operation and Development (OECD) data portal and included various health expenditure indicators, financing schemes and administrative data for all EU countries, the USA and Japan for the period 2018–2023. We have performed a structured analysis that explores correlations between these indicators, with a focus on financial schemes, expenditures and management sustainability. The analysis shows strong correlations between healthcare expenditures, financing schemes and administrative costs. Countries with efficient governance, balanced financing and proactive population health strategies (e.g., Japan and Nordic countries) demonstrate better management sustainability. However, countries like the USA and Eastern EU nations face challenges due to high administrative costs and inefficient financing models, respectively. Addressing these issues is critical to sustaining healthcare systems in the long term. The findings reveal that while Romanian providers excel in patient satisfaction and technological innovation, they lag behind their European counterparts in environmental sustainability and equitable access. Recommendations are proposed to address these gaps, drawing on successful strategies implemented in other European healthcare systems. This study fills a gap in the literature by providing a structured analysis of sustainability practices in Romania’s private healthcare sector, contextualized within a global comparative framework. Full article

The Eastern Aegean Sea hosts a diverse assemblage of elasmobranchs, many of which are vulnerable or endangered. This study presents a fishery-independent assessment of species composition, catch characteristics, and spatial patterns in bottom trawl fisheries between Lesvos Island and Ayvalik. A total of 48 surveys were conducted between September 2022 and October 2024, identifying nine elasmobranch species, with Scyliorhinus canicula (small-spotted catshark) and Mustelus mustelus (common smooth-hound) dominating the catch. Biological parameters, sex ratios, and condition upon capture and release were recorded, while catch per unit effort (CPUE) and diversity indices were used to evaluate temporal patterns. The survival probability was negatively affected by the trawl duration and elevated temperatures, emphasizing the need for mitigation measures. Spatial models revealed high-density zones that likely function as foraging or nursery grounds. Seasonal shifts in community composition were also evident. Many non-commercial species were discarded irrespective of their size or condition. These findings underscore the ecological importance of this understudied region and support the need for spatially explicit, species-specific management strategies, including gear selectivity improvements, seasonal closures, and Electronic Monitoring. The study offers a critical baseline for enhancing the sustainability of elasmobranch populations in the Eastern Mediterranean. Full article

Deep-sea trawling in the Mediterranean Sea, while economically significant, has profound ecological implications due to high discard rates and the practice’s impact on deep-sea biodiversity. This study examines the composition of discards and bycatch in Antalya Bay, a key deep-sea fishing area in the Eastern Mediterranean, during a commercial fishing season, focusing on seasonal and depth-related variations. Data were collected from deep-sea bottom trawl operations conducted between September 2016 and April 2017, analyzing species diversity and catch composition in terms of discarded and bycatch species. The results revealed an average discard rate of 70.7% of the total catch, with significant seasonal fluctuations. In total, 75 species were identified, comprising 48 Osteichthyes, 11 Elasmobranchii, 10 Crustacea, 4 Mollusca, 1 Brachiopoda, and 1 Echinodermata. Discarded species primarily consisted of juveniles of commercially valuable species (Merluccius merluccius and Lepidorhombus whiffiagonis), endangered elasmobranchs, and non-target benthic invertebrates. Depth-stratified analysis indicated that higher discard ratios and greater biodiversity loss occur at depths between 200 and 700 m, where slow-growing species and vulnerable deep-sea assemblages dominate. CPUE estimates for target, bycatch, and discarded species were calculated as 72.26, 145.12, and 385.52 kg/h, and CPUA values were calculated as 0.79, 1.59, and 2.92, respectively. These findings underscore the disproportionate impact of bottom trawling on deep-sea ecosystems and highlight the need for sustainable fisheries management strategies. Full article

Due to the ongoing global spread of the small hive beetle (SHB), Aethina tumida, there is a significant need for detection and practical management strategies against this pest. The standard inspection strategies for SHBs involve (1) detailed visual examination of the colony, which is challenging in areas with defensive bees, or (2) sampling beetles via traps, which requires repeated visits to the apiary and can be difficult for beekeepers with apiaries in rural areas. In this study, we modified the inspection sequence to examine the in-hive distribution of the beetle and assess whether a limited, yet targeted, inspection could provide valuable information on beetle infestation. We conducted our modified sampling in three different countries: Hawai’i (USA), Mexico, and Costa Rica. We found that targeted screening of the top areas of the hive (cover and top-side frames) provided reliable information about the relative prevalence of SHBs in a colony. The results also suggested that SHBs do not naturally congregate on a bare bottom board but migrate downward during inspection. Trap placement on the bottom floor of the hive may underestimate beetle presence in low to medium pest levels. The proposed inspection protocol is not influenced by the genetic origin of the bees (Africanized or European) and could be a practical alternative for assessing SHB infestation levels in honeybee colonies. Full article

Extra-pelvic varicose veins (VVs), originating from incompetent pelvic veins, present a significant clinical challenge, due to their complex anatomy, etiology, and symptomatology. This review aims at providing a comprehensive overview of the diagnostic and therapeutic strategies for these cases and emphasizes the importance of a tailored, evidence-based approach to the effective management of these varicosities, particularly regarding the interplay between the pelvic and extra-pelvic venous systems. Diagnostic workup should be multifaceted, incorporating patient-reported symptoms, physical examinations, and duplex ultrasound imaging. Specific diagnostic assessments include evaluation of the pelvic escape points and the transvaginal and transabdominal ultrasonography, to analyze venous hemodynamics and identify anatomical abnormalities in the pelvic floor and pelvis. In patients presenting with additional pelvic venous insufficiency (PVI)-related pelvic symptoms, advanced diagnostic techniques, such as cross-sectional imaging, venography, and intravascular ultrasound can be valuable to confirm and establish the appropriate treatment strategy. Since most patients with extra-pelvic VVs of pelvic origin do not report pelvic symptoms, minimally invasive procedures, using the “bottom-up” approach, such as ultrasound-guided foam sclerotherapy of the pelvic escape points and extra-pelvic VVs, or surgical ligation and miniphlebectomy for these incompetent veins, are usually sufficient. There are several advantages of these local procedures: they are simple, radiation exposure and injection contrast agents are avoided, they are convenient for the patient since they are performed on an outpatient basis, and they can be easily repeated, if required. When the “bottom-up” treatment fails and the extra-pelvic VVs recur quickly or the patient develops pelvic symptoms, management of the pelvic veins including embolization of the ovarian veins or stenting of the iliac veins should be considered. Careful patient selection is essential to avoid overtreatment and achieve optimal clinical outcomes. Full article

Travel and tourism are essential to global economies, generating social, economic, and environmental impacts. However, there is a lack of standardized methodologies to assess the environmental footprint of tourist destinations beyond carbon footprint analysis. This study introduces the Greentour tool, the first of its kind to evaluate the environmental impact of accommodation, restaurants, and tourism activities using nine environmental indicators from a life cycle assessment (LCA) perspective. The tool applies a hybrid bottom-up and top-down approach, integrating data from tourist establishments and destination managers. The tool was tested in four tourist destinations in Spain and Portugal (Rías Baixas, Camino Lebaniego, Lloret de Mar, and Guimarães), revealing that transportation is the primary contributor to environmental impacts, ranging from 60% to 96% of total emissions, particularly in air-travel-dependent destinations. Food and beverage services are the second-largest contributor, accounting for up to 26% of emissions, while accommodation ranks third (1–14%). This study highlights the significant role of electricity consumption and food choices (e.g., red meat and dairy) in greenhouse gas (GHG) emissions, emphasizing the need for sustainable alternatives. Despite challenges in data collection, particularly for food and transport statistics, the Greentour tool has demonstrated robustness and adaptability across diverse destinations, making it applicable worldwide. This tool provides key insights for policymakers, tourism stakeholders, and businesses, supporting the integration of sustainability strategies into public policies and industry best practices. Future research should focus on expanding its use to additional destinations to foster science-based decision-making and promote more sustainable tourism practices globally. Full article

Maritime transportation is responsible for most global trade and is generally considered more environmentally efficient compared to other modes of transport, particularly for long-distance trade. With increasingly stringent emission regulations, however, accurately quantifying emissions and identifying their key determinants has become essential for effective environmental management. This study introduced a structured and comparative statistical modeling framework for ship-based emission modeling using gross tonnage (GT) as the primary predictor variable, due to its strong correlation with emission levels. Emissions for hydrocarbon (HC), carbon monoxide (CO), particulate matter with an aerodynamic diameter of less than 10 μm (PM10), carbon dioxide (CO₂), sulfur dioxide (SO₂), nitrogen oxides (NO_x), and volatile organic compounds (VOC) were estimated using a bottom-up approach based on emission factors and formulas defined by the U.S. Environmental Protection Agency (EPA), using data from 38,304 vessel movements through the Bosphorus in 2021. These EPA-estimated values served as dependent variables in the modeling process. The modeling framework followed a three-step strategy: (1) outlier detection using Rosner’s test to reduce the influence of outliers on model accuracy, (2) curve fitting with 12 regression models representing four curve types—polynomial (e.g., linear, quadratic), concave/convex (e.g., exponential, logarithmic), sigmoidal (e.g., logistic, Gompertz, Weibull), and spline-based (e.g., cubic spline, natural spline)—to capture diverse functional relationships between GT and emissions, and (3) model comparison using difference performance metrics to ensure a comprehensive assessment of predictive accuracy, consistency, and bias. The findings revealed that nonlinear models outperformed polynomial models, with spline-based models—particularly natural spline and cubic spline—providing superior accuracy for HC, PM₁₀, SO₂, and VOC, and the Weibull model showing strong predictive performance for CO and NO_x. These results underscore the necessity of using pollutant-specific and flexible modeling strategies to capture the intricacies of maritime emission dynamics. By demonstrating the advantages of flexible functional forms over standard regression techniques, this study highlights the need for tailored modeling strategies to better capture the complex relationships in maritime emission data and offers a scalable and transferable framework that can be extended to other vessel types, emission datasets, or maritime regions. Full article

(1) Background: Planting density is an important factor affecting the yield of poplar per unit area. Therefore, determining the optimal height of the photosynthetic canopy layer for different planting densities is critical. (2) Methods: This study takes Populus euramericana ‘N3016’ × Populus ussuriensis as the research object. According to on the average tree height, diameter at breast height, and crown width of the stand, one standard tree was selected from each planting density for the experiment. The canopy of the standard tree was divided into five canopy layers from top to bottom, and the first-order lateral branches of each canopy layer were divided into three sites from outside to inside. The photosynthesis and leaf traits at various positions in different canopy layers were measured. (3) Results: The results revealed significant differences in photosynthetic and leaf traits at different positions of different canopy layers under different planting densities. As the canopy layer gradually declined, photosynthetic traits revealed that instantaneous photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (Gs) gradually decreased, while intercellular CO₂ concentration (Ci) increased. Moreover, water use efficiency (WUE) initially increased and then decreased under an 825 trees·ha⁻¹ (D3) planting density. Leaf traits revealed that as leaf length (LL) gradually decreased, leaf width (LW), leaf area (LA), and leaf water content (LWC) gradually increased. Under three planting densities, leaf traits were negatively correlated with Pn, Tr, WUE, and Gs, but positively correlated with Ci. (4) Conclusions: As the planting density decreased, the photosynthetic capacity of poplar gradually increased. With a planting density of D3, all canopy layers were able to carry out efficient photosynthesis, and all living branches within the canopy were functional. However, under the planting density of 1650 trees·ha⁻¹ (D1) and 1089 trees·ha⁻¹ (D2), canopy layers 1 to 4 could perform effective photosynthesis, while the photosynthetic capacity of canopy layer 5 was relatively weak. This study reveals the interactive effects of canopy position and stand density on leaf physiological and morphological traits, providing new insights into the photosynthetic efficiency and growth strategies of poplar under different planting densities. It also offers theoretical support for optimizing stand management and enhancing productivity. Full article