Search Results (156)

In the case of notched specimens, the introduction of additional stress relief holes (SRHs), or a local increase in the cross-section stiffness by means of composite overlays, decreases the stress level in the zone of the notch. The synchronous use of SRHs and composite patches has not been extensively investigated so far. Therefore, the main objective of the proposed research is to analyse the synergistic effect resulting from the simultaneous application of SRHs and structural reinforcement in the form of composite patches bonded to the bare steel element. The influence of this approach is investigated with the use of the finite element solution and experimental fatigue tests. As a result, a reduction in the stress concentration by almost 28% with respect to the bare plate with a hole was received. The use of composite overlays increases fatigue life by over 700% at the same cyclic tensile load in comparison with specimens without reinforcement and SRHs (base configuration). The use of reinforcement overlays or the synergetic application of overlays and SRHs guaranteed higher fatigue life (five and 10 times, respectively) at a higher load (by approximately 11%) compared to the base configuration. This confirmed the synergetic and positive influence of both modifications used in parallel. Full article

Rapid urbanization combined with global climate change is intensifying the Surface Urban Heat Island (SUHI) effect worldwide, posing significant risks to human health, thermal comfort, and quality of life in cities. Characterized by notably higher temperatures in urban areas compared to their rural surroundings, the SUHI phenomenon is driven by factors such as increased built-up density and reduced vegetation cover. In this context, open-source remote sensing data, particularly from the Landsat satellite series, play a crucial role in studying surface urban heat islands. Available freely, Landsat’s multispectral and thermal imagery provides extensive spatial coverage and consistent temporal frequency, enabling long-term diachronic analyses. This study leverages a 40-year time series (1984–2024) of Landsat thermal data to map surface temperature variations in urban environments between Kenitra and Rabat cities, facilitating the identification of heat-excess zones linked to anthropogenic factors. Based on the results obtained, the LU/LC maps show that the study area is characterized by the notable growth of urbanization over the period 1984–2024, particularly in the dynamic poles of the region such as the city centers of Kénitra, Rabat, and Sale. This dynamic is highlighted by an increase from 1.8% to 3% in the total area of the region, accompanied by a remarkable decrease in agricultural land and bare soils. The evaluation of the Random Forest (RF) model’s performance also indicates that it successfully classified the data and predicted the LU/LC classes effectively, as confirmed by metric indices such as the Receiver Operating Characteristic curve and the Kappa index, which present very high average values exceeding 90%. Furthermore, the exploitation of the thermal bands of Landsat images provided relevant information on surface temperature variation. The SUHI maps show that the Rabat-Sale-Kenitra (RSK) region experienced a progressive increase in temperature over the study period, rising from 27 °C in 1984 to 44 °C in 2024. This value could increase further due to the continuous dynamics of urbanization. Together, these tools provide a robust framework for understanding the spatiotemporal dynamics of surface urban heat islands and support sustainable urban planning. Full article

Lactase enzyme-based products experience challenges including residual lactose that result in lactose intolerance. The purpose of this study was to develop polyelectrolyte polysaccharide-enriched lactase-encapsulated liposomal hydrogel films as an edible coating of Perline Mozzarella cheese that delivers enzymes along with the product on the side of absorption in the small intestine. Coatings were investigated for shelf-life enhancement and in vitro enzyme release behaviour. Two different polymeric hydrogel film formulations were evaluated: lactase-encapsulated liposome-enriched chitosan (PCLLa) and lactase-encapsulated liposome-enriched polyelectrolyte chitosan and sodium alginate (CLLA). Lactase-encapsulated liposomes (mean particle size: 176 nm) were produced using 20% v/v lactase enzyme and 8% w/v lecithin using probe sonication. The edible hydrogel film coatings were applied on Perline Mozzarella cheese using the standard dip-coating method. Shelf-life characteristics of all samples were evaluated using pH, colour change, dry matter determination, microbial evaluation, and sensory analysis. CLLA coatings increased shelf life up to 60 days, displaying a pH of 5.48, continued normal colour, enhanced humidity balance, minimal bacterial growth, and the highest scores for sensory values when compared to both PCLLa (coatings) and the bare cheese substrate (control) samples. Furthermore, CLLA coatings provided greater stability for liposomes within the polyelectrolyte polymeric edible hydrogel film structure. Hence, the combination of liposomes with polyelectrolyte edible hydrogel films provides a novel strategy to enhance lactase enzyme encapsulation (for intolerance), stability, and delivering ability to the small intestine as well as improving the shelf life of coated cheese products. Full article

A significant portion of plastic products is not accepted by curbside recycling companies and goes to landfills or incineration, causing an adverse impact on the environment. This study investigated the effects of utilizing post-consumer plastic and e-waste in concrete. A plastic product made of thermoplastic polypropylene (PP) was ground into fine particles and used for 10% volumetric replacement of sand, while bare printed circuit boards (PCBs) were pulverized into powder and used for 10% cement replacement by mass. This study introduces a unique utilization of grounded powder PCBs by partially replacing cement in concrete. Furthermore, reinforced concrete beams with the replacements were constructed and tested under flexure for structural behavior evaluation. The results of this study show an average of 11% reduction in both the compressive strength of concrete and the maximum load capacity of the beams incorporating plastic products. A life cycle assessment study was conducted using a functional unit of 1.0 cubic yard concrete production. The system boundary for the environmental assessment of the concrete in this study includes only the production phase, which is from the cradle to the end gate of the ready-mix concrete plant. The environmental impact estimation of a 10% reduction in constituents of concrete showed a 10% reduction in most LCA measures where cement was replaced compared to a 1% effect for the fine aggregate replacement. Full article

Nickel is widely deployed in caustic service, yet its native Ni(OH)₂/NiOOH passive film raises concerns for long service life. Graphene has emerged as a promising corrosion barrier; however, its long-term durability in strongly alkaline media remains largely unexplored. The extended exposure period in a highly caustic solution is a novel aspect of the present work, distinguishing it from previous studies that predominantly examined short-term exposures or focused on neutral and acidic environments. Here, we present the systematic assessment of low-pressure CVD-grown multilayer graphene (MLG) coatings on Ni in highly caustic (0.5 M NaOH) for up to 80 days. Two architectures, a conformal, robust MLG coating (Gr_Ni) and a less robust film (Gr_Ni_DF), were benchmarked against bare Ni. PDP and EIS reveal that Gr_Ni initially delivers nearly 2 orders of magnitude enhancement, as evidenced by the low frequency impedance, accompanied by a broad, high-fidelity capacitive plateau; the impedance still maintains 1.3–1.5 orders of magnitude superior after prolonged exposure. In contrast, Gr_Ni_DF undergoes progressive degradation, affording a modest 2-fold benefit over time, consistent with defect-mediated electrolyte ingress. SEM morphologies further corroborate these trends, confirming the superior structural stability of Gr_Ni under extended alkaline immersion. Full article

Silicon windows in wafer-level packaged LWIR sensors suffer ~30% Fresnel reflection per interface, limiting optical throughput and detector sensitivity. We present an end-to-end design, fabrication, and validation framework for CMOS-compatible moth-eye anti-reflection coatings patterned directly on silicon wafers. Our approach integrates the effective medium theory, a transfer matrix analysis, full-wave FDTD simulations, and experimental Fourier-transform infrared (FTIR) measurements to optimize subwavelength pillar arrays for broadband (8–14 μm) and angle-tolerant performance. Fabricated structures demonstrate a 46.7% responsivity boost in CMOS–SOI–MEMS thermal sensors compared to bare silicon windows, while simulations predict up to 85.1% transmission and 57.1% responsivity enhancement for double-sided patterning. These results establish moth-eye metasurfaces as a scalable, CMOS-compatible solution for next-generation wafer-level processing and packaging infrared sensing platforms, transforming optical improvements into measurable electrical performance gains. The contribution of this work is the end-to-end framework for designing moth-eye wafer level processing and packaging for “real-life” CMOS-compatible infrared sensors manufacturing. Full article

Soil corrosion is a critical durability and cost factor for metallic foundations in photovoltaic (PV) power plants, yet it is still addressed with fragmented criteria compared with atmospheric corrosion. This paper reviews the main soil corrosivity drivers relevant to PV installations—moisture and aeration dynamics, electrical resistivity, pH and buffer capacity, dissolved ions (notably chlorides and sulfates), microbiological activity, hydro-climatic variability and geological heterogeneity—highlighting their coupled and non-linear effects, such as differential aeration, macrocell formation and corrosion localization. Building on this mechanistic basis, an engineering-oriented methodological roadmap is proposed to translate soil characterization into durability decisions. The approach combines soil corrosivity classification according to DIN 50929-3 and DVGW GW 9, tiered estimation of hot-dip galvanized coating consumption using AASHTO screening, resistivity–pH correlations and ionic penalty factors, and verification against conservative NBS envelopes. When coating life is insufficient, a traceable steel thickness allowance based on DIN bare-steel corrosion rates is introduced to meet the target service life. The framework provides a practical and auditable basis for durability design and risk control of PV foundations in heterogeneous soils. The proposed framework shows that, for soils exceeding AASHTO mild criteria, zinc corrosion rates may increase by a factor of 1.3–1.7 when chloride and sulfate penalties are considered, potentially reducing coating service life by more than 40%. The methodology proposed enables designers to estimate the penalty factors for sulfates ($f_p\left({SO}_4^{2-}\right)$) and chlorides ($f_p\left({Cl}^{-}\right)$) in each specific project, calculating the appropriate values of $K_{{SO}_4^{2-}}$ and $K_{{Cl}^{-}}$ using electrochemical techniques—ER/LPR and EIS—to estimate the effect of the soluble salts content in the ${Zn}_{Corr Rate}$, not properly catch by the proxy indicator $V_{corr}\left(ER, pH\right)$ when sulfate and chloride content are over AAHSTO limits for mildly corrosive soils. Full article

The use of drywall as a non-structural infill has grown significantly due to its rapid and economical installation. Despite this widespread use, a common assumption in structural design is that these elements do not significantly affect seismic performance and are often ignored in analysis. This assumption, however, is increasingly questioned. This study presents a full-scale experimental evaluation of the influence of drywall infill on the seismic response of reinforced concrete frames under cyclic loading. The results quantify how the inclusion of these non-structural elements alters the dynamic properties and structural response of the frame. The infill increased the initial lateral stiffness by approximately three times with respect to the bare frame, thus modifying the structure’s fundamental period. The infill also altered the failure mechanism, initiating with a transient compression strut action at very low drifts, which rapidly and concurrently transitioned into a dominant membrane behavior. This membrane contribution ceased abruptly at a drift of 0.89%, prior to the life-safety limits specified by Eurocode 8. The study’s findings demonstrate the necessity of incorporating the non-linear stiffness and energy dissipation of drywall into structural models to ensure reliable and accurate predictions in seismic design methodologies. Full article

Recent scholarship has studied the extensive transformation of Turkey’s Directorate of Religious Affairs (Diyanet) over the past two decades as embodying a form of religious populism that mobilizes civilizational antagonisms. Based on a directed qualitative content analysis of Friday sermons, official publications, online material, broadcasts, and public statements by Diyanet leaders, this article makes three contributions. First, while confirming that the Diyanet promotes the civilizational unity of the ummah and casts Turkey as the spiritual custodian of a transhistorical Islamic world, the analysis shows that anti-elitist framings characteristic of populism are barely present in its rhetoric. Second, the article provides a detailed examination of gönül coğrafyası (geography of the heart), a widely invoked yet understudied concept through which the Diyanet reimagines Ottoman-Islamic heritage as a sacred topography of civilizational belonging and responsibility. Third, it examines how Europe is situated both outside and within this imagined geography: at once a constitutive and menacing “other” marked by Islamophobia and cultural decay yet also a moral frontier inhabited by Muslim diasporas through whom Turkish Islam extends its reach. By drawing such symbolic boundaries, the Diyanet frames Islam as both religious patrimony and ethical alternative to Western modernity, portraying itself as a key actor in the re-sacralization of modern life across borders. Full article

A university campus is a composite built environment integrating research, daily life, culture, and ecological green space. Its landscape elements shape environmental perception and overall spatial quality. This study assesses spatial quality by identifying key features and optimizing their joint effects across three perceptions: safety, comfort, and belonging. Using a Chinese campus, we captured street-view images, applied semantic segmentation to quantify elements (grass, trees, buildings, roads, sidewalks), and used explainable machine learning with data augmentation to identify the features most relevant to these perceptions. This study then employed fuzzy-set Qualitative Comparative Analysis (fsQCA) to reveal configuration pathways that enhance spatial quality. Results show that data augmentation mitigates class imbalance and improves prediction accuracy. Key features include sky, river, bridge, people, grass, and sidewalks, and path analysis indicates that greater sky openness and higher densities of people, roads, sidewalks, and grass, together with fewer buildings, cars, and bare earth, enhance safety, comfort, and belonging. This study delivers globally transferable design rules and a replicable, policy-ready workflow that enables evidence-based campus upgrades across diverse regions. Full article

Street design quality and socio-economic factors jointly influence housing prices, but their intertwined effects and spatial variations remain under-quantified. Housing prices not only reflect residents’ neighborhood experiences but also stem from the spillover value of public streets perceived and used by different users. This study takes Tianjin as a case and views the street environment as an immediate experience proxy for through-travelers, combining street view images and crowdsourced perception data to extract both subjective and objective indicators of the street environment, and integrating neighborhood and location characteristics. We use Geographical-XGBoost to evaluate the relative contributions of multiple factors to housing prices and their spatial variations. The results show that incorporating both subjective and objective street information into the Hedonic Pricing Model (HPM) improves its explanatory power, while local modeling with G-XGBoost further reveals significant heterogeneity in the strength and direction of effects across different locations. The results indicate that incorporating both subjective and objective street information into the HPM enhances explanatory power, while local modeling with G-XGBoost reveals significant heterogeneity in the strength and direction of effects across different locations. Street greening, educational resources, and transportation accessibility are consistently associated with higher housing prices, but their strength varies by location. Core urban areas exhibit a “counterproductive effect” in terms of complexity and recognizability, while peripheral areas show a “barely acceptable effect,” which may increase cognitive load and uncertainty for through-travelers. In summary, street environments and socio-economic conditions jointly influence housing prices via a “corridor-side–community-side” dual-pathway: the former (enclosure, safety, recognizability) corresponds to immediate improvements for through-travelers, while the latter (education and public services) corresponds to long-term improvements for residents. Therefore, core urban areas should control design complexity and optimize human-scale safety cues, while peripheral areas should focus on enhancing public services and transportation, and meeting basic quality thresholds with green spaces and open areas. Urban renewal within a 15 min walking radius of residential areas is expected to collaboratively improve daily travel experiences and neighborhood quality for both residents and through-travelers, supporting differentiated housing policy development and enhancing overall quality of life. Full article

Carbide-bonded graphene (CBG) coating, with its unique 3D cross-linked network structure, shows significant potential for protecting silicon substrates. However, a comprehensive understanding of its macroscale tribological properties remains lacking. This study investigated the macroscale friction and wear behaviors of CBG-coated silicon wafers using reciprocating sliding tests against steel balls under various loads and sliding cycles. The CBG coating exhibited excellent friction-reduction and anti-wear performance, reducing the steady friction coefficient from 0.80 to 0.17 and wear rate by an order of magnitude compared to those of bare silicon. Higher loads slightly decreased both friction coefficients and wear rates, primarily due to the formation of denser tribofilms and transfer layers. Re-running experiments revealed three distinct wear stages—adhesive, abrasive, and accelerated substrate wear—driven by the evolution of tribofilms, transfer layers, and unabraded flat areas. Furthermore, comparative experiments confirmed that these “unabraded flat areas” on the wear track play a critical role in sustaining low friction and prolonging coating life. The findings identify CBG as a robust solid lubricant for high-contact-pressure applications and emphasize the influence of tribo-layer dynamics and wear debris behavior on coating performance. Full article

Stable productivity is the basis for efficient and sustainable use of perennial grasslands, holding both ecological and economic importance. Alfalfa-based mixtures have great potential to achieve this goal. There was limited information on the impact of species combination and seeding ratio on their long-term production performance and stability. We investigated forage yield, quality, and temporal stability over six years in alfalfa (Medicago sativa)/timothy (Phleum pretense) and alfalfa/smooth bromegrass (Bromus inermis) mixtures at varying seeding ratios. Alfalfa/grass mixtures showed a yield advantage over grass monocultures with greater yield at higher alfalfa seeding proportions (50% or more). The mixtures showed advantages in crude protein and neutral detergent fiber. Crude protein content tended to increase with increasing alfalfa seeding proportion, while fiber contents barely changed. As stands grew older, forage yield increased and then declined and showed greater stability in mixtures compared with monocultures. The percentage of alfalfa yield tended to increase over the life of the stand. In contrast, forage quality varied over the life of the stand, with greater variability in mixtures than monocultures. Considering forage yield, quality, and stability across years, smooth bromegrass would be more compatible with alfalfa in a mixture compared to timothy for the Longdong Loess Plateau of China and areas with similar climates. Full article

To prolong the service life of asphalt pavement and reduce its maintenance cost, a fiber Bragg grating (FBG) sensor encapsulated in carboxylated carbon nanotube (CNT-COOH)-modified gel material suitable for strain monitoring of asphalt pavement was developed. Through tensile and bending tests, the effects of carboxylated carbon nanotubes on the mechanical properties of gel materials under different dosages were evaluated and the optimal dosage of carbon nanotubes was determined. Infrared spectrometer and scanning electron microscopy were used to compare and analyze the infrared spectra and microstructure of carbon nanotubes before and after carboxyl functionalization and modified gel materials. The results show that the incorporation of CNTs-COOH increased the tensile strength, elongation at break, and tensile modulus of the gel material by 36.2%, 47%, and 17.2%, respectively, and increased the flexural strength, flexural modulus, and flexural strain by 89.7%, 7.5%, and 63.8%, respectively. Through infrared spectrum analysis, it was determined that carboxyl (COOH) and hydroxyl (OH) were successfully introduced on the surface of carbon nanotubes. By analyzing the microstructure, it can be seen that the carboxyl functionalization of CNTs improved the agglomeration of carbon nanotubes. The tensile section of the modified gel material is rougher than that of the pure epoxy resin, showing obvious plastic deformation, and the toughness is improved. According to the data from the calibration experiment, the strain and temperature sensitivity coefficients of the packaged sensor are 1.9864 pm/μm and 0.0383 nm/°C, respectively, which are 1.63 times and 3.61 times higher than those of the bare fiber grating. The results of an applicability study show that the internal structure strain of asphalt rutting specimen changed linearly with the external static load, and the fitting sensitivity is 0.0286 με/N. Combined with ANSYS finite element analysis, it is verified that the simulation analysis results are close to the measured data, which verifies the effectiveness and monitoring accuracy of the sensor. The dynamic load test results reflect the internal strain change trend of asphalt mixture under external rutting load, confirming that the encapsulated FBG sensor is suitable for the long-term monitoring of asphalt pavement strain. Full article

Thoracic endovascular aortic repair (TEVAR) for cardiovascular diseases often encounters complications that are closely linked to the mechanical properties of stent-grafts. Both the design and material properties influence device performance, but the specific impacts of material properties remain underexplored and poorly understood. This study aims to fill this gap by systematically investigating how material science can modulate stent-graft mechanics. Four types of bare nitinol stents combined with expanded polytetrafluoroethylene (e-PTFE) or polyethylene terephthalate (PET) grafts were modeled via finite element analysis, creating eight stent-graft configurations. Key mechanical properties—flexibility, crimpability, and fatigue performance—were evaluated to dissect material effects. The results revealed that nitinol’s properties significantly influenced all performance metrics, while PET grafts notably enhanced flexibility and fatigue life. No significant differences in equivalent stress were found between PET and e-PTFE grafts, and both had minimal impacts on radial force. This work underscores the potential of material science-driven optimization to enhance stent-graft performance for improved clinical outcomes. Full article