Search Results (142)

Solving competitive facility location problems can optimize market share or operational efficiency in environments where multiple firms compete for customer attention. In such contexts, facility attractiveness is shaped not only by geographic proximity but also by customer preference characteristics. This study presents a novel heuristic framework that integrates multi-view K-means clustering with customer behavior modeling reinforced by a co-regularization mechanism to align clustering results across heterogeneous data views. By jointly exploiting spatial and behavioral information, the framework clusters customers and facilities into meaningful market segments. Within each segment, a bilevel optimization model is applied to represent the sequential decision-making of competing entities—where a leader first selects facility locations, followed by a reactive follower. An empirical evaluation on a real-world dataset from San Francisco demonstrates that the proposed approach, using optimal co-regularization parameters, achieves a total runtime of approximately 4.00 s—representing a 99.34% reduction compared to the full CFLBP-CB model (608.58 s) and a 99.32% reduction compared to a genetic algorithm (585.20 s). Concurrently, it yields an overall profit of 16,104.17, which is an approximate 0.72% increase over the Direct CFLBP-CB profit of 15,988.27 and is only 0.21% lower than the genetic algorithm’s highest profit of 16,137.75. Moreover, comparative analysis reveals that the proposed multi-view clustering with co-regularization outperforms all single-view baselines, including K-means, spectral, and hierarchical methods. This superiority is evidenced by an approximate 5.21% increase in overall profit and a simultaneous reduction in optimization time, thereby demonstrating its effectiveness in capturing complementary spatial and behavioral structures for competitive facility location. Notably, the proposed two-stage approach achieves high-quality solutions with significantly shorter computation times, making it suitable for large-scale or time-sensitive competitive facility planning tasks. Full article

Implementing energy-efficient solutions and developing energy complexes to decentralise power supply are key objectives for enhancing national security in Ukraine and Eastern Europe. This study compares the design, numerical, and experimental parameters of a channel-type jet-reaction turbine. A steam turbogenerator unit and a pilot industrial experimental test bench were developed to conduct full-scale testing of the unit. The article presents experimental data on the operation of a steam turbogenerator unit with a capacity of up to 475 kW, based on a channel-type steam jet-reaction turbine (JRT), and includes the validation of a computational fluid dynamics (CFD) model against the obtained results. For testing, a pilot-scale experimental facility and a turbogenerator were developed. The turbogenerator consists of two parallel-mounted JRTs operating on a single electric generator. During experimental testing, the system achieved an electrical output power of 404 kW at a turbine rotor speed of 25,000 rpm. Numerical modelling of the steam flow in the flow path of the jet-reaction turbine was performed using ANSYS CFX 25 R1 software. The geometry and mesh setup were described, boundary conditions were defined, and computational calculations were performed. The experimental results were compared with those obtained from numerical simulations. In particular, the discrepancy in the determination of the power and torque on the shaft of the jet-reaction turbine between the numerical and full-scale experimental results was 1.6%, and the discrepancy in determining the mass flow rate of steam at the turbine inlet was 1.34%. JRTs show strong potential for the development of energy-efficient, low-power turbogenerators. The research results confirm the feasibility of using such units for decentralised energy supply and recovering secondary energy resources. This contributes to improved energy security, reduces environmental impact, and supports sustainable development goals. Full article

A three-year optimization study was conducted at a mechanical biological treatment plant with the aim of enhancing organic fractions recovery from mechanically separated fine fractions (MSFF) of residual waste using a screw press. The study aimed to optimize key operating parameters for the employed screw press, such as pressure, liquid-to-MSFF, feeding quantity per hour, and press basket mesh size, to enhance volatile solids and biogas recovery in the generated press water for anaerobic digestion. Experiments were performed at the full-scale facility to evaluate the efficiency of screw press extraction with other pretreatment methods, like press extrusion, wet pulping, and hydrothermal treatment. The results indicated that hydrolysis of the organic fractions in MSFF was the most important factor for improving organic extraction from the MSFF to press water for fermentation. Optimal hydrolysis efficiency was achieved with a digestate and process water-to-MSFF of approximately 1000 L/ton, with a feeding rate between 8.8 and 14 tons per hour. Increasing pressure from 2.5 to 4.0 bar had minimal impact on press water properties or biogas production, regardless of the press basket size. The highest volatile solids (29%) and biogas (50%) recovery occurred at 4.0 bar pressure with a 1000 L/ton liquid-to-MSFF. Further improvements could be achieved with longer mixing times before pressing. These findings demonstrate the technical feasibility of the pressing system for preparing an appropriate substrate for the fermentation process, underscoring the potential for optimizing the system. However, further research is required to assess the cost–benefit balance. Full article

A core tertiary wastewater reactive filtration technology, where continuously renewed hydrous ferric oxide coated sand is created in an upflow continuous backwash filter, has been adopted in about 100 water resource recovery facilities in several countries. Primarily focused on ultralow phosphorus discharge requirements to address nutrient pollution impacts and harmful algae blooms, the technology has also demonstrated the capacity to address high-efficiency removals of Hg, As, Zn, N, and other pollutants of concern, in addition to water quality needs met by common sand filtration, including total suspended solids. Recent work has demonstrated the capability of an additive iron–ozone catalytic oxidation process to the core reactive filtration technology platform to address micropollutants such as pharmaceuticals. Most recently, direct injection of frangible biochar into the reactive sand filter bed as a consumable reagent demonstrates a novel biochar water treatment technology in a platform that yields dose-dependent carbon negativity. In this work, the reactive filtration technology performance is reviewed from field pilot-scale to full-scale installation scenarios for nutrient removal and recovery applications. We also review the potential of the technology for nutrient recovery with the addition of biochar and micropollutant destructive removal with catalytic oxidation. Research exploration of this reactive filtration technology includes life cycle assessment (LCA) and techno-economic assessment to evaluate the environmental and economic impacts of this advanced water treatment technology. A recent LCA study of a pilot-scale field research and full-scale municipal system with over 2200 inventory elements shows a dose-dependent carbon negativity when biochar is injected into the process stream of reactive filtration. In this study, LCA demonstrates that reactive filtration has the potential as a negative emissions technology with −1.21 kg CO₂e/m³, where the negative contribution from the dosed biochar is −1.53 kg CO₂e/m³. In this biochar water treatment configuration, the system not only effectively removes pollutants from wastewater but also contributes to carbon sequestration and nutrient recovery for agriculture, making it a potentially valuable approach for sustainable water treatment. Full article

This study presents the long-term performance evaluation of a full-scale hybrid membrane bioreactor (MBR)–nanofiltration (NF) system for the treatment of high-strength municipal landfill leachate from the Istanbul–Şile Kömürcüoda facility. Over a 16-month operational period, influent and effluent samples were analyzed for key parameters, including chemical oxygen demand (COD), ammonium nitrogen (NH₄⁺-N), total phosphorus (TP), suspended solids (SS), and temperature. The MBR unit consistently achieved high removal efficiencies for COD and NH₄⁺-N (93.5% and 98.6%, respectively), while the NF stage provided effective polishing, particularly for phosphorus, maintaining a TP removal above 95%. Seasonal analysis revealed that the biological performance peaked during spring, likely due to optimal microbial conditions. To support intelligent control strategies, artificial neural network (ANN) models were developed to predict effluent COD and NH₄⁺-N concentrations using influent and operational parameters. The best-performing ANN models achieved R² values of 0.861 and 0.796, respectively. The model’s robustness was validated through RMSE, MAE, and 95% confidence intervals. Additionally, Principal Component Analysis (PCA) and Random Forest algorithms were employed to determine the parameter importance and nonlinear interactions. The findings demonstrate that the integration of hybrid membrane systems with AI-based modeling can enhance treatment efficiency and forecasting capabilities for landfill leachate management, offering a resilient and data-driven approach to sustainable operation. Full article

Sludge management constitutes a significant share of the operational costs in wastewater treatment. Given the financial and bureaucratic challenges associated with implementing new technologies, process optimization often represents the most feasible approach for existing facilities. This study presents the results of four full-scale batch stabilization tests conducted in the aerobic sludge stabilization unit of a wastewater treatment plant in northern Italy. The objective was to evaluate the potential of alternating oxic–anoxic cycle stabilization in terms of the energy consumption and sludge treatment performance. Operational parameters were monitored and evaluated. Stabilized and dewatered sludge samples, as well as the liquid fraction from the dewatering process, were collected and analyzed. Energy consumption was continuously monitored. Data were normalized and a comparative model was developed to evaluate performance against traditional continuous aeration, using results from previous tests. The findings indicate that alternating cycle stabilization achieved comparable stabilization efficiency to continuous aeration, with an energy demand of about one-third of that required for continuous aeration. Additional benefits of the alternating cycle strategy included improved nitrogen removal and enhanced sludge dewaterability. This experimental study demonstrates how full-scale functional testing in existing treatment units can support process optimization within a circular economy framework, contributing to reduced resource consumption and an improved sludge quality. Full article

The durability of permeable pavement needs to be further studied by accelerated pavement testing (APT). Full-scale APT facilities are commonly associated with a very high initial investment and operational costs. A piece of small-scale accelerated testing equipment, the model mobile load simulator (MMLS), was used to investigate and evaluate the mechanical properties of three types of permeable asphalt pavements, including a 4 cm porous asphalt layer with cement-treated permeable base (4PA-CTPB), 7 cm porous asphalt layer with cement-treated permeable base (7PA-CTPB), and 7 cm porous asphalt layer with cement-treated base (7PA-CTB). Under different conditions of subgrade soil, transverse and longitudinal strains at the bottom of the porous asphalt layer and average rut depth and temperature data were collected. The results indicated that 4PA-CTPB produced the maximum average rut depth but minimum resilient tensile strain. The transverse resilient tensile strain of 7PA-CTPB was significantly higher than the other two structures under both wet and dry conditions. The transverse resilient tensile strain significantly increased with increasing loading cycles with a decreasing rate, which could be affected by both load and temperature. MMLS could be used to explore and evaluate the mechanical properties of permeable asphalt pavement. From the data under dry and wet conditions, it may be better to increase the strength of the subgrade, where a suitable hydraulic conductivity coefficient should be considered. Full article

Sequencing batch reactor Grundfos technology (SBR-GT) system efficiently treats municipal and selected industrial wastewater, designed for small and medium-scale facilities. It offers advanced solutions for biodegradable wastewater, including municipal and food industry effluents. Important features include stable sedimentation under fluctuating influent conditions, no need for sludge recirculation, and full process automation. The system uses a static decanter and constant chamber filling for optimal oxygenation efficiency and reduced costs. The system uses a static decanter and constant chamber filling for optimal oxygenation efficiency and reduced costs. It is ideal for small settlements with variable inflow, such as towns, allowing flexible operation and cost-effective maintenance. Implementations showed stable parameters for COD (chemical oxygen demand), BOD5 (biochemical oxygen demand), total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP) and up to 99% pollutant reduction, demonstrating high effectiveness in regular and stormwater conditions. Using multivariate multiple linear regression, significant relationships were identified. A multiple regression analysis revealed a strong relationship between water quality parameters. Total suspended solids, Total nitrogen, and Total phosphorus collectively and significantly influenced both chemical oxygen demand and biochemical oxygen demand (p < 0.01 for all). The models explained a high proportion of variance, with R² values of 0.99 for COD and 0.93 for BOD5 (p < 0.001 for both). Specifically, TSS had a strong positive effect on COD (p < 0.001), while TN and TP also significantly affected COD (p < 0.01). Although the overall BOD5 model was highly significant, the individual effects of TSS, TN, and TP on BOD5 were not statistically significant in this model. This method demonstrated high effectiveness in both regular and stormwater conditions, enhancing overall treatment performance. Full article

Highly contaminated waste from an old mercury mine facility was covered with fly ash from a coal-burning power plant that was analyzing the rainwater infiltration in a full-scale test in which the influencing variables were monitored for a year. A sufficiently low hydraulic conductivity and sufficiently high porosity of the ash, and the relationship between evapotranspiration and precipitation were the most important factors controlling rainwater infiltration through the fly ash layer to produce contaminated leachate. A fly ash layer with a thickness between 10 and 50 cm, depending on climatic conditions, works as a barrier to partially or totally prevent, depending on the scenario considered, rainwater contamination. Overall, the solution proposed in this study results in economic savings in all the cases considered, because treatments for eliminating PTEs from waste are usually expensive. On the other hand, the effect is permanent over time, as it is based on a physical barrier effect, while the contamination reduction is independent of the initial concentration and the contamination reduction is for any PTE (Hg, Pb, Zn, etc.). Full article

Managing special pathogens cases, also known as high consequence infectious diseases, presents unique challenges for healthcare systems. It requires thorough planning and comprehensive operational protocols, as well as an appreciation of how human and organizational factors influence readiness. Based on the outcomes from a full-scale Ebola Virus Disease exercise at New York City Health and Hospitals (NYC Health + Hospitals), this paper presents a checklist of considerations to promote healthcare facility preparedness for special pathogens and to minimize gaps between protocol design and real-world implementation. This approach not only strengthens compliance with the new Joint Commission requirements but also provides a replicable framework for enhancing special pathogens preparedness within other healthcare systems. Full article

This study investigates the time-resolved aerodynamics in the cavity regions of a full-scale, high-speed, low-pressure turbine stage representative of geared turbofan engines. The turbine stage is tested in the von Karman Institute’s short-duration rotating facility at different purge rates (PR) injected through the upstream hub cavity. Spectra from the shroud and downstream hub cavity show perturbations linked to blade passing frequency and rotor speed. Asynchronous flow structures associated with ingress/egress mechanisms are observed in the rim seal of the purged cavity. At 0% PR, the ingress region extends to the entire rim seal, and pressure fluctuations are maximized. At 1% PR, the instability is suppressed and the cavity is sealed. At 0.5%, the rim-seal instability exhibits multiple peaks in the spectra, each corresponding to a state of the instability. Kelvin–Helmholtz instabilities are identified as trigger mechanisms. A novel technique based on the properties of the cross-power spectral density is developed to determine the speed and wavelength of the rotating structures, achieving higher precision than the commonly used cross-correlation method. Moreover, unlike the standard methodology, this approach allows researchers to calculate the structure characteristics for all the instability states. Spectral analysis at the turbine outlet shows that rim-seal-induced instabilities propagate into regions occupied by secondary flows. A methodology is proposed to quantify the magnitude of the induced fluctuations, showing that the interaction with secondary flows amplifies the instability at the stage outlet. Full article

The conception of a circular economy is one of the crucial approaches that could accelerate the processes of achieving sustainable development goals, which challenge all industries and societies. Still, the potential of agricultural waste in this area is not fully covered by technologies. This study aims to develop a full-scale technology for self-sustaining double-stage circularity through the utilization of sunflower agriculture’s waste in bio-fertilizers. The investigation is performed in Bulgaria, as available sunflower husk ashes (SHA) are subjected to analyses regarding their applicability for bio-fertilizer production. The design of the technology and full-scale equipment commissioning process are described. The conditions and results from the adjustment tests are presented and, based on these, the optimal operating parameters are defined. The successful granulation of different samples of SHA at these conditions is performed and the final granular bio-fertilizers are characterized with a content of 30 wt. % K₂O and 5% wt. P₂O. The moisture of the prepared granules is approx. 5 wt. %, and they pass the crushing tests at 2.5 kgf. The biotoxicity of the bio-fertilizer is also analyzed, and the results show its applicability in agriculture. The proposed approach allows the initial sources of K₂O and P₂O from soil feeding the sunflowers to circulate in different industrial technologies and to reenter the soil through bio-fertilizers. Full article

Background: Sports science and medicine (SSM) is integral to professional football clubs. The level below professional football in England, ‘non-league football’ (NLF), consists of full-time and part-time clubs. The existing literature has exclusively focused on SSM in professional football, with the resources and practices in NLF currently unknown. Therefore, this study explored the SSM resources and practices within NLF by investigating the perspectives of key stakeholders working within NLF coaching and SSM disciplines. Methods: Fifty participants (coaching practitioners [n = 25] and SSM practitioners [n = 25]) from NLF clubs completed an anonymous online survey comprising 31 multiple-choice and Likert-scale questions, alongside optional open-ended comments. Results: Support was mixed for SSM evidence-based practices across clubs in Tiers 5–10 within the National League System. The most common SSM resources were the training ground (n = 39), resistance training equipment (n = 15), and rehabilitation area (n = 13). Fitness testing was frequent (86%) pre-season but rare end-of-season (8%). Workload monitoring primarily consisted of the session duration (80%) and time–motion data (36%). Performance analysis of competitive matches commonly used video (74%) or post-match technical analysis (40%). Injury monitoring generally occurred ‘always’ (44%) or ‘sometimes’ (28%). Nutritional support on match days was mostly fluids (80%), with ‘no support’ reported most outside match days (54%). Conclusions: The SSM resources and practices vary considerably within NLF, influenced by individual club constraints and barriers, including financial support, access to facilities, and equipment availability. These findings may inform future SSM provisions in NLF to enhance team performances and player availability. Full article

Agricultural land classification plays a pivotal role in food security and ecological sustainability, yet achieving accurate large-scale mapping remains challenging. This study presents methodological innovations through a multi-level feature enhancement framework that transcends traditional time series analysis. Using Shandong Province, northern China’s agricultural heartland, as a case study, we first established a foundation with time series red-edge vegetation indices (REVI) from Sentinel-2 imagery, uniquely combining the normalized difference red edge index (NDRE₇₀₅) and plant senescence reflectance index (PSRI). Moving beyond conventional time series analysis, we innovatively amplified key temporal characteristics through newly designed spatial feature parameters (SFPs) and phenological feature parameters (PFPs). This strategic enhancement of critical temporal points significantly improved classification performance by capturing subtle spatial patterns and phenological transitions that are often overlooked in traditional approaches. The study yielded three significant findings: (1) The synergistic application of NDRE₇₀₅ and PSRI significantly outperformed single-index approaches, demonstrating the effectiveness of our dual-index strategy; (2) The integration of SFPs and PFPs with time series REVI markedly enhanced feature discrimination at crucial growth stages, with PFPs showing superior capability in distinguishing agricultural land types through amplified phenological signatures; (3) Our optimal classification scheme (FC6), leveraging both enhanced spatial and phenological features, achieved remarkable accuracy (93.21%) with a Kappa coefficient of 0.9159, representing improvements of 4.83% and 0.0538, respectively, over the baseline approach. This comprehensive framework successfully mapped 120,996 km² of agricultural land, differentiating winter wheat–summer maize rotation areas (39.44%), single-season crop fields (36.16%), orchards (14.49%), and facility vegetable fields (9.91%). Our approach advances the field by introducing a robust, scalable methodology that not only utilizes the full potential of time series data but also strategically enhances critical temporal features for improved classification accuracy, particularly valuable for regions with complex farming systems and diverse crop patterns. Full article

Acoustic lice treatment (AcuLice) is a newly developed system which uses a composite acoustic sound image with low-frequency sound to remove salmon lice (Lepeophtheirus salmonis) from Atlantic salmon (Salmo salar). The effect of AcuLice treatment on salmon lice dynamics was measured by weekly salmon lice counting at a full-scale production facility from mid-summer 2019 to late-spring 2024. We monitored four production cycles, with AcuLice applied for two of the production cycles and with no AcuLice treatment applied during the other two production cycles as control. This is a follow-up study to our previous work. The numbers of salmon lice treatments and of weeks until the first salmon lice treatment were also compared in the two experimental groups. For the small (sessile and mobile stages) salmon lice, a significantly lower number (mean ± SEM) was shown for the AcuLice group (0.73 ± 0.03) compared with the control group (1.18 ± 0.05). For the mature female salmon lice, a significantly lower number (mean ± SEM) was found for the AcuLice group (0.12 ± 0.01) compared with the control group (0.22 ± 0.03). In addition, the mean (±SEM) number of C. elongatus varied between the two experimental groups and was higher in the control group (0.12 ± 0.01) compared with the AcuLice group (0.03 ± 0.01). In addition, a lower number (mean ± SEM) of salmon lice treatments (1.4 ± 0.17 vs. 4.22 ± 0.20) and a longer production period before the first salmon lice treatment occurred was observed for the AcuLice group (11.2 ± 0.1 weeks) compared with the control group (24.1 ± 2.3 weeks). These data suggest that the use of the AcuLice system significantly reduces the number of salmon lice (by 40–60%) and C. elongatus (by 70%) on farmed Atlantic salmon and reduces the need for traditional salmon lice treatments (by 65%). Full article