Search Results (145)

Bottle tops made of polythene (PE) and polypropylene (PP) are a major source of terrestrial plastic pollution in the United Arab Emirates (UAE). This study looks at the occurrence, distribution and fate of plastics derived from bottle tops in the area of Al Ain, Eastern region of Abu Dhabi, UAE. Photo-oxidative degradation of the plastics in the hot, arid environment of Al Ain can be followed by infrared spectroscopy and quantified by the oxidation index (OxI). The oxidation index can be used to estimate the residence time of the plastic in the open environment. Oxidation of plastic bottle tops in the open environment over a period of 15 months leads to brittleness. Easy fragmentation of the tops can occur upon impact with another body, resulting in meso- and microplastics. This was demonstrated by the effect that a hailstorm as a single weather event had on an experimental “field” of plastic bottle tops set out in the open. Here, the oxidation index was a good indicator of whether the plastic fragmented or stayed intact. To reduce the contamination of the environment with plastic bottle tops, it is suggested that legislation be developed similar to the EU’s Single-Use Plastics Directive requiring that plastic bottle tops remain attached to their bottles. This also aligns with the principles of a more circular economy. Full article

Single-use plastics (SUPs) impose substantial environmental costs. Following Directive (EU) 2019/904, Austria introduced producer charges and mandatory participation in collection and recycling systems. This paper exploits a monthly aggregated and disaggregated panel of retail offer spells drawn from a price-comparison platform to estimate the extent to which compliance costs pass through to posted online prices in Austria. The treated sample comprises keyword-matched SUP products—balloons, to-go cups, wet wipes, plastic bags, food containers, tobacco-filter items, beverage bottles, and plastic wraps—observed alongside a control group of non-SUP listings over 2020–2024. A two-way fixed-effects (TWFE) specification places the average post-treatment price increase at approximately 4.1 percent. A sequential TWFE model that disaggregates the administrative reporting phase (from March 2023) from the payment-due phase (from March 2024) reveals that the larger adjustment occurs during the earlier reporting stage, with a reporting-only effect of approximately 8.1 percent and an incremental payment-phase effect of 5.6 percent. For balloons—a category subject to pronounced regulatory fee exposure—event-study estimates exceed 50 percent in the months immediately following the initial payment date and remain elevated throughout most of the post-treatment window. Taken together, these findings indicate that Austrian online retailers began adjusting prices in advance of fee-payment deadlines, a pattern consistent with anticipatory pass-through of expected compliance costs rather than a discrete response to realized payments. As the data contain price observations but not quantity data, the analysis speaks to price incidence and does not extend to consumption or environmental outcomes. Full article

High-entropy alloys, due to their excellent mechanical properties and service stability, hold broad application prospects under extreme working conditions. However, their high strength and complex multi-component characteristics also pose significant processing challenges. This study investigates the nanoscale material removal mechanisms of single-crystal and polycrystalline FeCrNiCoCu high-entropy alloys (HEAs) under abrasive scratching using molecular dynamics simulations. In single-crystal HEAs, dislocations preferentially nucleate along <110> directions, with significant lattice self-healing and elastic recovery. Crystallographic orientation strongly affects dislocation density, phase transformation, and residual plastic deformation, with the (100) plane exhibiting the most favorable machining performance. For polycrystalline HEAs, subsurface deformation is dominated by dislocation migration, grain boundary rupture, and dislocation entanglement, leading to higher dislocation density, larger residual plastic deformation, and increased phase transformation compared with single crystals. Elemental composition significantly modulates these behaviors: higher Cu and Cr contents suppress dislocation motion and reduce subsurface defects, improving surface quality, whereas higher Fe content slightly increases plastic deformation but mitigates phase transformation and amorphization. Grain size effects are also pronounced, with smaller grains showing higher dislocation density and residual deformation. These findings provide atomic-scale insights into the combined effects of crystallography, grain size, and elemental composition on the machining response of FeCrNiCoCu HEAs, offering guidance for precision machining and alloy design. Full article

Expansive soils pose significant challenges in geotechnical engineering due to their volume changes with moisture variations. A critical distinction exists between a soil’s inherent potential to swell or shrink (governed by intrinsic parameters such as clay content, plasticity index, and activity index) and its actual behaviour under specific site conditions (governed by state parameters like porosity and water content). This paper critically evaluates the reliability of widely used single-index and multi-index classification methods against direct oedometer measurements of swelling pressure. Analysis of nearly 600 tests on natural active clays from four different sites in Romania reveals that, for these soils and site conditions, no single intrinsic parameter—nor any simple pair of parameters—correlates reliably with swelling pressure, demonstrating that these indices merely indicate potential, not actual, behaviour. In contrast, state parameters provide more meaningful insights. Drawing on parallels with collapsible soil mechanics, the study introduces the concept of “saturation-independent pressure” (si_p), the stress level beyond which saturated and natural-moisture soil behaviours converge. Furthermore, a practical calculation method is proposed for estimating both foundation heave (upon saturation) and shrinkage (upon drying), based on double oedometer compressibility curves. Notably, a strong correlation (R² = 0.79–0.86) is demonstrated between swelling pressure and the specific swelling strain measured under an initial load of 12.5 kPa, offering a rapid and inexpensive screening tool for identifying potentially problematic active clays. Full article

This study examines the associations among perceived policy effectiveness, emotional environmental engagement, and environmental behavior in the context of the plastic bag charge policy in Turkey. While market-based environmental policies are typically explained in terms of economic incentives, the ways in which policy perceptions and emotional processes are associated with individual behavior remain underexplored in the literature. The data were collected through a nationwide survey in Turkey (n = 515), and the proposed model was tested using Structural Equation Modeling (SEM). The measurement model shows good fit (CFI = 0.94; TLI = 0.92; RMSEA = 0.05; SRMR = 0.04). The findings indicate that perceived policy effectiveness is positively and significantly associated with emotional environmental engagement (β = 0.56, p < 0.001). Emotional engagement is also strongly associated with environmental behavior (β = 0.62, p < 0.001). The direct association between perceived policy effectiveness and environmental behavior is weaker but remains significant (β = 0.21, p < 0.01). Bootstrap analysis (5000 resamples) indicates a significant indirect association (β = 0.35; 95% CI [0.21, 0.49]), suggesting that emotional environmental engagement represents an important explanatory dimension linking perceived policy effectiveness and environmental behavior. Given the cross-sectional and self-reported nature of the data, these findings should be interpreted as associative rather than strictly causal. Nevertheless, the results suggest that the relationship between policy perceptions and environmental behavior is more consistent with a framework in which emotional processes are jointly involved, rather than a purely economic explanation. By examining perceived policy effectiveness, emotional environmental engagement, and environmental behavior within a single analytical framework, this study provides an integrated empirical account of how market-based environmental policies are associated with individual-level environmental behavior. Full article

In recent decades, the issue of marine litter has emerged as a major environmental concern, particularly with regard to plastic litter. The European Marine Strategy Framework Directive (MSFD, 2008/56/EC) requires member states to monitor marine litter along the coast, in the water, and on the seabed. Since 2014, beach litter monitoring has been carried out in Italy’s coastal regions, an activity entrusted to the Regional Environmental Agencies System (ARPA). ARPA Puglia is responsible for monitoring the Apulian coastline, and this paper summarizes the main results obtained from 2014 to 2023. The monitoring, which was repeated twice a year, consists of a visual census of litter items along a 100-meter stretch of beach in six different locations across the Puglia region. During this period, an average of 506 litter items per 100 m were observed on the six target beaches in Puglia, 90% of which were plastic ones. Among these, single-use plastic items (SUPs) accounted for 37%. A trend analysis reveals a decline in the aggregate quantity of marine litter on Apulian beaches over the past decade, a phenomenon that is particularly evident when considering the SUP subcategory in isolation. This decreasing trend is consistent with the overall pattern observed along the Italian coastline and the coastlines of European seas. Consequently, it can be hypothesized that an increase in awareness of the issue, in conjunction with the implementation of European Directive 2019/904 for the reduction in single-use plastics, has resulted in more responsible practices. However, further efforts are needed to achieve the goal of 20 litter items per 100 m of beach to attain the Good Environmental Status under the Marine Strategy Framework Directive. The findings emphasize the importance of constant monitoring of litter items along the shoreline, as well as the integration of new and alternative methodologies (e.g., drone surveys) to evaluate the efficacy of European regulatory implementation. Full article

The mandatory introduction of tethered caps on plastic beverage bottles under European Directive (EU) 2019/904 aims to reduce plastic litter and improve the collection efficiency of packaging waste. This regulatory change introduced a packaging design modification that directly affects consumer interaction. Consumer acceptance of this packaging innovation, however, remains uncertain. Drawing on research suggesting that product experience is shaped not only by physical interaction but also by expectations and value-based framing, this study examines whether the environmental intent of tethered caps is reflected in consumer perceptions over time. We analyze changes in consumer attitudes toward tethered caps before and after the legal obligation came into force, based on survey data collected in 2024 and 2025. Results indicate that overall consumer perceptions remained predominantly negative in both years, with a slight increase in negative responses following mandatory implementation. Although reported awareness of single-use plastic issues was higher in 2025, this did not correspond to improved evaluations of usability. Skepticism regarding the actual impact on waste reduction, along with ergonomic concerns and discomfort during drinking, were consistently identified as key barriers to acceptance. Socio-demographic analysis showed that age and employment status significantly influenced attitudes, whereas gender and place of residence did not. Contrary to expectations, younger respondents showed a shift toward more negative perceptions after implementation. Overall, the results suggest that the EU Single-Use Plastics Directive, although primarily aimed at achieving positive environmental outcomes, did not produce a comparable effect on consumer perception, as the environmental rationale did not significantly increase the acceptability of the tethered cap among users. This highlights the limits to value-based acceptance of sustainability-driven packaging measures and underscores the importance of integrating user-centered evaluation into regulatory design and communication strategies. These insights contribute to the broader discussion on the effectiveness of regulatory packaging interventions in the beverage sector. Full article

This study aims to investigate the influence of clay mineral content on the rheological properties and long-term deformation stability of clays, and to establish a unified model capable of quantitatively describing the nonlinear rheological behavior of clays with different mineral compositions. Direct shear rheological tests were conducted on specimens prepared with different mixing ratios of bentonite, kaolin, and quartz. Combined with micro-mechanism analysis, the controlling factors of clay rheological behavior were explored. The experimental results show that the creep stress threshold, elastic viscosity, and average plastic viscosity decrease significantly with increasing clay mineral content. The rheological deformation exhibits distinct nonlinear characteristics, and clay mineral content plays a controlling role in the rheological behavior. Based on experimental and mechanistic analysis, a unified rheological model was established, which reflects the material origin of rheology and captures nonlinear rheological characteristics. This model can predict the entire time-history mechanical behavior of clays with different mineral compositions across the three stages of instantaneous deformation, decay rheology, and steady-state rheology under different shear stress levels using a single set of parameters. Validation was performed through direct shear rheological tests under 50 working conditions for five types of clay specimens, demonstrating good consistency between the model calculations and experimental results. The unified rheological model reveals the material origin and physical essence of clay rheology, demonstrates high universality, and advances the understanding of the influence of mineral composition on rheology from the current phenomenological qualitative description to quantitative calculation for the first time, significantly enhancing its engineering application value. This provides a more reliable tool for predicting long-term deformation and assessing the stability of clay foundations. Full article

The mechanical behavior of metallic core–shell nanoparticles is critical for their use as reinforcement particles and additive manufacturing feedstocks, yet their deformation mechanisms remain incompletely understood. This study employs molecular dynamics simulations to investigate the compressive response of a Cu-core/Al-shell nanoparticle and compares it with solid Cu, solid Al, and a hollow Al shell of the same size under uniaxial loading along ⟨100⟩, ⟨110⟩, ⟨111⟩, and ⟨112⟩ directions. The single-material nanoparticles show strong anisotropy: solid Cu exhibits orientation-dependent transitions from dislocation slip to deformation twinning, while introducing a void to form a hollow Al shell reduces stiffness and strength, confines plasticity to the shell wall, and suppresses extended load-bearing twins. The Cu–Al core–shell nanoparticle combines these behaviors in an orientation-dependent manner. Under ⟨110⟩ and ⟨112⟩ loading, deformation is largely shell-dominated, whereas ⟨100⟩ and ⟨111⟩ loading more strongly activates the Cu core. Mechanistically, ⟨100⟩ is characterized by Shockley partial activity and junction/lock formation in the Al shell coupled with twinning in the Cu core; ⟨110⟩ shows primarily shell partials with limited core involvement; ⟨111⟩ promotes partial-dislocation activity in both shell and core; and ⟨112⟩ produces localized, twin-dominated bands in the Al shell with shell-thickness-dependent twin extension into the Cu core. These trends are rationalized using Schmid factor considerations for $\left\{111\right\}⟨110⟩$ slip and $\left\{111\right\}⟨112⟩$ partial/twinning shear, together with the effects of faceted free surfaces and the Cu–Al interface. The core–shell geometry enables two concurrent interface-mediated pathways, i.e., (i) stress transfer and reduced cross-interface transmission and (ii) circumferential bypass within the shell, which together yield only slight flow-stress increases over solid Al while markedly reducing stress serrations compared with both solid Cu and solid Al. Across all orientations, the core–shell structures also exhibit delayed yielding (higher yield strain) relative to solid Cu, indicating enhanced ductility. The results provide an atomistic basis for designing Cu–Al core–shell nanoparticles for robust particle-based processing and additive manufacturing feedstock, and for informing multiscale models with mechanism-resolved, orientation-dependent inputs. Full article

Using the ultrasonic burnishing process to fabricate micro-textures is one of the effective methods to improve the hydrophobic properties of workpiece surfaces. In this study, three ultrasonic burnishing strategies—single-pass ultrasonic burnishing process (SUBP), two-pass ultrasonic burnishing process with reverse feed direction (TUBP-RF), and two-pass ultrasonic burnishing process with forward feed direction (TUBP-FF)—were employed to fabricate micro-textures on 316 stainless steel pipes. The effects of burnishing strategy and feed rate on surface morphology and hydrophobic performance were investigated. TUBP-RF introduces reverse feed in the second pass, generating tangential forces in the opposite direction that induce secondary plastic flow and material accumulation at texture intersections. The results show that surface hydrophobicity first increased and then decreased with increasing feed rate, reaching its maximum at 0.7 mm/r. TUBP-RF achieved the highest contact angle of 108°, representing increases of 18.4% and 12.1% compared with SUBP and TUBP-FF, respectively. Among the three strategies, TUBP-RF produces interlaced micro-textures with larger peak height Rp, medium peak spacing RSm, and reduced effective solid contact area, facilitating air entrapment beneath water droplets and promoting a Cassie–Baxter wetting state. Furthermore, under the optimal parameters of the TUBP-RF process, the machined surface improved droplet sliding speed, reduced the sliding time by 61.7% compared with the original surface. The TUBP-RF strategy effectively enhances surface hydrophobic properties by constructing interlaced micro-textures, offering new insights for optimizing the ultrasonic burnishing process. Full article

This paper presents a compact floating memtranstor (MT) emulator, a memory element characterized by a direct φ–q relationship, realized without analog multipliers or complex circuitry. The proposed design employs only two active blocks—a voltage differential transconductance amplifier (VDTA) and a voltage differential current conveyor (VDCC)—along with three grounded capacitors and a single grounded electronically tunable resistor. The emulator accurately reproduces the fundamental φ–q dynamics, exhibiting origin-crossing pinched hysteresis loops under sinusoidal excitation, and operates at a low supply voltage of ±0.9 V. Electronic tunability is achieved via bias-controlled transconductance modulation, enabling flexible adaptation across excitation frequencies and operating conditions. Validation is performed through analytical modeling, Monte Carlo simulations, temperature sensitivity analysis, and full LTspice post-layout simulations using a 180 nm CMOS process. The full-custom layout occupies 2529.49 μm², with robust performance confirmed under parasitic and process variations. Adaptive learning simulations demonstrate the emulator’s artificial synaptic plasticity, highlighting its suitability for neuromorphic computing, chaos-based circuits, and nonlinear dynamical systems. The compact, low-power, and multiplier-free architecture establishes the proposed MT emulator as a practical platform for emerging analog memory-centric applications. To validate the feasibility of the proposed solution, experimental tests are performed using commercially available components. Full article

This study proposes an AI-based framework for impact analysis of wooden structures, focusing on quantitatively assessing how individual seismic elements and their spatial locations influence structural response. A single-story residential building was used as a case study. Numerical time-history analyses were performed using a detailed three-dimensional nonlinear model, and parametric variations in stiffness and strength were systematically generated using an orthogonal array. Machine learning models were then trained to investigate the relationship between these parameters and seismic responses, and explainable artificial intelligence (XAI) techniques, including SHAP, were applied to evaluate and interpret parameter influences. The results suggest that wall elements oriented parallel to the target inter-story drift direction generally have the greatest effect on seismic response. Quantitative analysis indicates that the relative importance of these elements roughly corresponds to their wall lengths, providing physically interpretable evidence. Model comparisons show that linear regression achieves high accuracy in the elastic range, while Gradient Boosting performs better under strong excitations inducing nonlinear behavior, reflecting the transition from elastic to plastic response. SHAP-based analysis further provides insights into both the magnitude and direction of parameter influence, enabling element- and location-specific interpretation not readily obtained from traditional global sensitivity measures. Overall, the findings indicate that the proposed framework has the potential to support the identification of influential structural elements and the quantitative assessment of their contributions, which could assist in informed engineering decision-making. Full article

Droplet microarrays are increasingly used for miniaturized, high-throughput biochemical assays, yet their fabrication commonly relies on complex lithographic processes, custom masks, or specialized coatings. Here we present a simple method for generating hydrophilic arrays on hydrophobic plastic substrates by combining ultrasonic atomization with off-the-shelf perforated masks. A fine mist of poly(vinyl alcohol) (PVA) solution is directed through commercial diamond sieves onto polypropylene (PP) sheets and polystyrene (PS) sheets, forming hydrophilic spots surrounded by the native hydrophobic background. Static contact angle measurements confirm a strong local contrast in wettability (from 100.85 ± 0.91° on untreated PP to 39.96 ± 0.71° on patterned spots, from 95.68 ± 3.61° on untreated PS to 52.00 ± 0.85° on patterned spots), while Image analysis shows droplet CVs of 6–8% in aqueous dye solutions for 1.2–2.0 mm masks; in complex media (LB), droplet uniformity decreases. By mounting the moving mask on a motorized stage, we generate one-dimensional reagent gradients simply by controlling the moving mask motion during atomization. We further demonstrate biological compatibility by culturing Escherichia coli in LB droplets containing resazurin, and by performing localized antibiotic screening using a moving mask-guided streptomycin gradient. The resulting droplet-wise viability data yield an on-chip dose–response curve with an IC₅₀ of 5.1 µg · mL⁻¹ (95% CI: 4.5–5.6 µg·mL⁻¹), obtained from a single array. Covering droplets with Electronic Fluorinated Fluid maintains volumes within 5% of their initial value over 24 h. Compared with conventional droplet microarray fabrication, the proposed method eliminates custom mask production and cleanroom steps, is compatible with standard plastic labware, and intrinsically supports spatial gradients. These attributes make masked ultrasonic atomization a practical platform for high-throughput microfluidic assays, especially in resource-limited settings. Full article

The widespread use of antibiotics, combined with pervasive exposure to diverse environmental media, has intensified the global challenge of antibiotic resistance. Accumulating evidence reveals that beyond direct antibiotic pressure, residual non-antibiotic chemicals—despite lacking intrinsic antibacterial activity—can significantly promote the enrichment and spread of antibiotic resistance genes (ARGs) in farmland soils through indirect mechanisms such as inducing oxidative stress, altering microbial community structure, and enhancing both vertical and horizontal gene transfer. To address this issue, the present study investigates the influence of representative non-antibiotic contaminants commonly detected in agricultural environments—including pesticides (e.g., Omethoate, imidacloprid, and atrazine), industrial pollutants (e.g., PCB138, BDE47, benzo [a] pyrene, 2,3,7,8-tetrachlorodibenzo-p-dioxin [TCDD], and benzene), plastic-associated compounds (e.g., Polyethylene trimer, phthalates, and tributyl acetylcitrate), and ingredients from personal care products (e.g., triclosan and bisphenol A)—on ARG transmission dynamics. Leveraging bioinformatics resources such as the CARD database, PDB, AlphaFold, and molecular sequence analysis tools, we identified relevant small-molecule ligands and macromolecular receptors to construct a simulation system modeling ARG transfer pathways. Molecular docking and molecular dynamics (MD) simulations were then implemented, guided by a Plackett–Burman experimental design, to systematically evaluate the impact of individual and co-occurring pollutants. The resulting data were processed using advanced analytical tools, and MD trajectories were interpreted at the molecular level across three scenarios: an unperturbed (blank) system, single-pollutant exposures, and dual-pollutant combinations. By integrating computational simulations with machine learning approaches, this work uncovers the “co-selection” effect exerted by non-antibiotic chemical residues in shaping the environmental resistome, thereby providing a mechanistic and scientific basis for comprehensive risk assessment of agricultural non-point source pollution and the development of effective soil health management and antimicrobial resistance containment strategies. Full article

Accurate evaluation of unsaturated shear strength remains a significant challenge in geotechnical engineering because of the nonlinear interaction between matric suction and shear strength. Existing models often assume a linear contribution of suction and are generally restricted to low suction ranges, limiting their predictive capability under highly unsaturated conditions. This study investigated the nonlinear response of unsaturated shear strength through single-stage direct shear tests conducted under constant water content. Two soil types: a high-plasticity clay and a low-plasticity silty clay were examined across a wide suction range extending beyond the air-entry value (AEV). The results revealed a nonlinear behavior expressed as a distinct bi-linear trend, with shear strength increasing with suction up to the optimal moisture condition and then exhibiting a clearly altered rate of increase at higher suction levels. To capture this nonlinear behavior of unsaturated shear strength with suction, an exponential shear strength equation was proposed and validated using eight additional published datasets encompassing different soil classifications and suction magnitudes. The proposed formulation demonstrates that accounting for non-linearity is essential for accurately estimating the unsaturated shear strength of the soil. Moreover, the proposed exponential model outperforms both the well-established linear model of Fredlund and the nonlinear power law model of Abramento and Carvalho, thereby providing a unified framework for capturing the nonlinear interaction of matric suction on unsaturated shear strength. Full article