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Progress in modified electrospun PVC membranes: Toward sustainable solutions for environmental remediation
No full textPublisher Copyright: © 2024 Elsevier B.V.Electrospun polyvinyl chloride (PVC) membranes exhibit chemical resistance, durability, and ease of fabrication, making them efficient in filtration applications. Recently, their exploitation has been expanding, particularly as adsorptive filters for water purification and air filtration processes, due to their ability to be modified for enhanced selectivity and efficiency in removing pollutants. This review paper provides a comprehensive overview of recent advancements in modified electrospun PVC membranes with the focus on environmental applications, such as water and air remediation. The review explores various modification strategies employed to enhance the membranes’ performance in pollutant removal. Additionally, it addresses the challenges and prospects associated with these modified membranes, including durability, reusability, scalability, cost-effectiveness, and long-term performance stability. By highlighting the potential of these modified electrospun PVC membranes in tackling heavy metal contamination, dye pollution, and air quality issues, this review aims to shed light on the advancement of sustainable and efficient membranes for environmental remediation.Peer reviewe
Do Deadlines Affect Project Completion? Experimental Evidence from Israeli Vocational Colleges
No full textWe study a large-scale intervention aimed at increasing graduation rates in Israeli vocational colleges. In this context, the main reason for low graduation rates has been found to be the failure of students to complete the required final project. This may result from procrastination which is prevalent among students in many settings. To address procrastination, we introduce a deadline for final project defense in randomly selected departments while control group departments maintain the practice of scheduling defense dates on a rolling basis. We compare student performance over time in treated and control departments in a difference-in-differences framework and find no effect of deadlines on project defense or on graduation rates. A potential explanation for these findings is that there are other constraints faced by students, such as academic difficulties or a low perceived value of the diploma, which are not alleviated by the deadline. Using administrative and survey data, we find that deadlines have no effect even when the alternative constraints are not binding.Peer reviewe
Chemical Substitution and Band Gap Tunability in Chiral Ag3Au(Se,Te)2 Solid Solutions
No full textPublisher Copyright: © 2025 American Chemical Society.Ag3AuSe2 and Ag3AuTe2 were previously predicted to be narrow direct gap semiconductors with the same chiral structure type. Recent computational studies using the Perdew-Burke-Ernzerhof (PBE) functional highlighted their potential band gap tunability via strain application. For example, Ag3AuSe2 was predicted to exhibit full band closure above 4% tensile strain. In this study, we explored chemical substitution to examine the density functional theory (DFT) predictions by replacing Se2- with larger Te2- anions. We synthesized and characterized the electronic and optical properties of Ag3Au(Se1-xTex)2 solid solutions for x from 0 to 1. Our findings revealed that the lattice constants increase linearly with Te incorporation, reaching 3.6% expansion at 90% Se2- to Te2- substitution. The activation energy and optical band gap of Ag3Au(Se,Te)2 were determined by using electrical resistivity and ultraviolet-visible (UV-vis) diffuse reflectance measurements. The band gap decreased with increasing Te content, although hybrid functionals are necessary to correctly predict the gap. Further computational studies on the band structures of Ag3Au(Se,Te)2 alloys would shed light on the impact of lattice parameter modification via chemical substitution on the band gap tunability.Peer reviewe
Fabrication of polydimethylsiloxane/zinc oxide/silica nanocomposite for steel coating: Improving physical and mechanical properties of polydimethylsiloxane
No full textPublisher Copyright: © 2024 Elsevier LtdIn this study, silica and zinc oxide nanoparticles are incorporated into polydimethylsiloxane (PDMS) at various concentrations, as well as mixtures of these nanoparticles at two different concentrations, to synthesize nanocomposite materials for coating the surface of plain carbon steel. The best-performing nanocomposite, PDMS-SiO2-ZnO, demonstrates remarkable improvements in mechanical properties compared to pure PDMS and other fabricated nanocomposites. It shows a maximum final stress of 165 MPa, elongation of 15.46 mm, and Young's modulus of 14 MPa/mm. These values are significantly higher than those of pure PDMS, with tensile strength and Young's modulus being 2.75 and 8.75 times greater, respectively. Additional findings reveal that PDMS-SiO2-ZnO not only exhibits superior mechanical properties but also shows enhanced stiffness and uniform nanoparticle dispersion with no signs of agglomeration. The presence of ZnO nanoparticles contributes to a higher crystallization tendency in this specimen, as shown by XRD analysis. Furthermore, FTIR spectroscopy confirms the absence of disturbing peaks in this specimen. Contact angle testing demonstrates increased hydrophilicity of the steel coated with this specimen, with 46-degree and 3-degree increases compared to uncoated steel and steel coated with pure PDMS, respectively. Tafel polarization corrosion tests reveal enhanced corrosion resistance in the steel specimen coated with this material, with a decrease in corrosion current density to 2 × 10–6 A/cm² compared to uncoated steel (5 ×10–4 A/cm²) and steel coated with pure PDMS (4 ×10–5 A/cm²). The corrosion potential also improves from −0.71 V and −0.58 V to −0.55 V compared to uncoated steel and steel coated with pure PDMS, respectively. Altogether, these findings underscore the potential of PDMS-SiO2-ZnO nanocomposites as effective coatings for improving the mechanical properties, hydrophilicity, and corrosion resistance of carbon steel surfaces, offering promising applications in various industries requiring durable and protective surface coatings.Peer reviewe
Research on inland ship hydrodynamic modeling and parameter identification based on CFD
No full textPublisher Copyright: © 2024Hydrodynamic modeling and the calculation of hydrodynamic derivatives for Inland ships have consistently presented challenges. This paper introduces a method for building ship maneuvering models utilizing Computational Fluid Dynamics (CFD) and the Maneuvering Motion Group (MMG) models. Forces and moments acting on the hull from fluid dynamics to predict calculating the hydrodynamic derivatives of unconventional ship hulls. Static Oblique Towing Tests (OTT) and Dynamic Circular Motion Tests (CMT) are used to collect synthetic data for the 3 Degrees of Freedom (DOF) of the MMG model. To improve the fitting accuracy of parameter identification of MMG model, this study suggests using an interpolation fitting method instead of the traditional least squares fitting method. Considering the unique characteristics of the research object of this paper, the reliability of its maneuvering model is validated through the creation of a scaled ship model corresponding to the CFD computational model. Ship model maneuvering tests, including the 15/15 Zigzag test, are conducted to refine certain propeller and rudder parameters. The proposed method is applied to the inland ship (ANJI 209 wheel). The results show that the mathematical model, established using interpolation fitting to determine hydrodynamic derivatives, accurately forecasts the ship maneuvering features, which is corroborated by the experimental data from ship model tests.Peer reviewe
Photocatalytic N-formylation of amines with CO2 over Pt-Bi bimetallic decorated CeO2−x
No full textPublisher Copyright: © 2024 Elsevier B.V.N-formylation of amines with CO2 is a promising approach to high-efficient utilization of CO2 as C1 feedstock, while conventional thermocatalytic processes suffer from harsh reaction condition and intense energy consumption. In this work, photocatalytic N-formylation of amines with CO2 is achieved at room temperature over Pt-Bi/CeO2−x composite catalyst. The Pt-Bi bimetallic sites increase the concentration of surface oxygen vacancies. Furthermore, the synergistic effects of Pt and Bi improve the light absorption capacity, reduce the band gap energy of the photocatalyst and promote the separation of photoinduced charge carriers. Using PhSiH3 as the reducing agent, the conversion of N-methylaniline reaches 100 % after 3 h irradiation in N, N-dimethylformamide solvent with a N-methylformanilide selectivity of 90.8 %. The composite photocatalyst shows promising cycling stability and universality.Peer reviewe
A bird’s-eye view of the relationships between economic complexity, time, and the importance of HRM actors
No full textThis study adopts a contextual approach to understand the prominence of HRM department specialists, outsourced HRM service providers and line managers in the HRM function. Drawing on resource dependence theory and research on the professionalisation of HRM, we look at how national economic complexity (EC) and the passage of time shape the need for these actors in an organisation’s HRM. Our analysis is based on Cranet data from five survey rounds conducted between 2000 and 2022, covering 30,651 organisations across 54 countries. Our results show that higher levels of EC are associated with smaller HRM departments, less devolution and greater outsourcing of non-core HRM activities. Over time, HR staff ratios and outsourcing of non-core and core HRM activities increase, while devolution declines. Interestingly, we also observe that the negative effects of EC on HR staff ratios and devolution are eventually reversed. This suggests that in more complex economies, the prominence of all HR actors increases over time, which reflects a growing organisational commitment to managing people. Our findings highlight how economic and temporal contexts shape the HRM function.Peer reviewe
Secure Edge Intelligence in the 6G Era
No full textPublisher Copyright: © 2025 John Wiley & Sons, Ltd. All rights reserved.Future 6G networks are expected to enable smart and hyperconnected society where various digital services and applications will be ubiquitously available to the users. 6G networks will have diverse and strict requirements related to computation, communication, network, and resource, which may include ultralow latency, higher bandwidth, reliability, real-time data analytics, and intelligent decision-making among others. edge intelligence (EI) is among the potential technology enablers that can play a pivotal role in achieving these requirements for 6G networks. Since 6G networks will bring wider security threats landscape, their integration with the edge computing, artificial intelligence (AI) and other technologies will make them even more complex and highly vulnerable to various threats. Therefore, it is crucial to place strong, efficient, and intelligent security mechanisms for EI-enabled 6G networks. In this chapter, we discuss various potential security, privacy, and trust challenges for EI in the context of future 6G networks and briefly explore the relevant standardization activities.Peer reviewe
A novel data-driven method of ship collision risk evolution evaluation during real encounter situations
No full textPublisher Copyright: © 2024Aiming at realizing collision risk quantitative evaluation among encounter ships, a novel data-driven evolution model is proposed concerning encounter evolution in maritime transportation. A probabilistic velocity obstacle with an elliptic conflict region is constructed by taking into account uncertainty. The degree of and time to domain violation are introduced to quantify collision risk levels under varying velocities. Then, a ship collision risk evolution model is formulated by considering spatial attributes, macro-level and micro-level evolution based on a realistic collision avoidance decision. The model parameters and their weights are determined by statistical analysis of historical encounter scenarios and the characteristics of encounter stages. Therefore, the model encapsulates the statistical characteristics of actual data, which improves its practical values. The results of case studies indicate that the collision risk evolution model can properly reflect collision risk, so that collision evolution stages can be classified accordingly for rational anti-collision guidance. It brings new contributions to risk visualization, collision avoidance decision-making, and collision accident analysis and responsibility determination.Peer reviewe
The Social Significance of Solar-PV Cooking – A Case Study of an Innovative Intervention in Zambia
No full textTraditional biomass-based sources have historically dominated cooking fuels in many African countries, despite their recognized drawbacks. While renewable energy technologies offer a promising solution, a successful energy transition requires understanding socio-cultural contexts and values. This case study examines the social significance of electric cooking on household members and evaluates intervention effectiveness in rural Zambia. Based on primary data from focus groups and interviews with beneficiaries and non-beneficiaries of solar stoves, sustained use of electric cooking was confirmed. Time-saving and cost-savings of using electric cooking have been evaluated. Significant differences in social impact perception were found among family members: women primarily value smoke-free cooking, time savings, and income generation, while men emphasize cost savings. Variations also exist between girls and boys. Integration of a battery system, community engagement, and awareness campaigns have enhanced stove ownership's perceived value and impact. This study also explores the potential of enhancing future clean cooking interventions by introducing internet access to the scheme. Despite several identified challenges, community socio-cultural practices could be leveraged to overcome these obstacles.Peer reviewe