Quantitative ammonia (NH3) sensing with chemiresistive devices is strongly affected by temperature and relative humidity (RH), compromising calibration reliability under variable conditions. Here, we establish an environmental compensation framework using a PANI/SnS2 device for NH3 detection, a PEDOT:PSS/SnO2 device for temperature sensing, and a MoS2 device for RH sensing. The temperature-sensing device exhibits a temperature coefficient of resistance of −1.38 % °C−1 over 20–50 °C, while the RH-sensing device shows a sensitivity of 1.53 %/% RH over 25–90 % RH. Temperature, RH, and the PANI/SnS2 response are subsequently incorporated into five regression models for NH3 concentration prediction. Gradient boosting regression performs best on an independent test set, achieving R 2 = 0.95, a mean absolute error of 2.18 ppm, and a root-mean-square error of 3.57 ppm. Compared with the uncompensated model, environmental compensation reduces the root-mean-square error by 47.3 %. These results demonstrate that incorporating environmental information substantially improves quantitative NH3 estimation under variable environmental conditions and provides a basis for future development of integrated NH3 monitoring systems.
The utilization of natural soils in combination with industrial waste materials for landfill liner applications represents a sustainable approach to reducing environmental impacts while enhancing waste management practices. In this study, a series of laboratory investigations were conducted to evaluate the engineering performance of composite liner materials prepared using natural bentonite (15 % and 25 %), sand (75 %, 80 %, and 85 %), and waste marble dust (20 %, 25 %, and 30 %). The geotechnical properties of the proposed liner mixtures were assessed through a comprehensive testing program, including Atterberg limits, unconfined compressive strength (UCS), consolidation in order to find hydraulic conductivity, free swell index, and direct shear tests. Furthermore, mineralogical and chemical characteristics were examined using X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses to provide insight into the microstructural behavior of the composite liners. The experimental results demonstrated that all tested mixtures exhibited geotechnical characteristics suitable for landfill liner applications. An increase in bentonite content led to a reduction in maximum dry density and a corresponding increase in optimum moisture content, reflecting the higher water absorption capacity of clay-rich mixtures. Specimens containing 25 % bentonite exhibited greater free swell indices than those containing 15 % bentonite. Nevertheless, all mixtures were classified as low-swelling materials, as their swelling percentages remained below 0.5 %. The shear strength parameters were also influenced by bentonite content. Specifically, higher bentonite proportions resulted in increased cohesion values, whereas lower bentonite contents produced greater internal friction angles. In addition, all mixtures exhibited low shrinkage limits and minimal volumetric changes, indicating favorable dimensional stability under varying moisture conditions. Based on the experimental results, the mixture containing 25 % bentonite and 25 % marble dust was identified as the optimum composition among the investigated mixtures. This selection was primarily based on its low hydraulic conductivity (which has been obtained by consolidation test), which is the key requirement for landfill liner applications, while its satisfactory unconfined compressive strength was considered as a complementary criterion for mechanical performance. Thus, the 25 % bentonite–25 % marble dust mixture provided the most favorable combination of impermeability and mechanical strength among the tested mixtures.
This study systematically investigates how ligands on CoFe2O4 nanoparticles control the magnetoelectric (ME) performance of poly(vinylidene fluoride) (PVDF)-based multiferroic composites and modulate the behavior of mesenchymal stem cells (MSCs) cultured on these surfaces. Particles bearing different organic coatings (polyethylene glycol, oleylamine, oleic acid, citric acid, and uncoated) were incorporated into a PVDF matrix and characterized by nanoparticle dispersion, interfacial coupling, bulk and local ME response, and magnetically mediated effects on adherent cells. Bulk ME coefficients ranged from 10 to 38 mV cm−1 Oe−1 for oleic acid- and oleylamine-coated particles, respectively, a variation attributable to differences in dispersion and polymer–filler coupling. Localized surface measurements revealed signals up to 6,000 mV cm−1 Oe−1 in oleic acid-containing films, consistent with nanoparticle aggregation and surface-localized piezoactive spherulites. Both oleylamine- and oleic acid-containing composites induced the formation of densely packed mesenchymal stem cell aggregates, morphologically resembling mesenchymal condensation under ME stimulation, but only the oleylamine-containing composite enhanced the density of adherent cells. These findings delineate coating-dependent mechanisms for tuning ME outputs and provide concrete design criteria for flexible biocompatible ME scaffolds.
This study presents a comprehensive review of green concrete mixtures incorporating supplementary cementitious materials (SCMs), integrating the compiled data with statistical modelling, optimization, and environmental and economic assessment. A systematic survey (2000–2026) of Scopus and Web of Science narrowed 1995 articles to 34 through two-stage screening, yielding 337 experimental data points. Unlike conventional reviews, a second-order response surface methodology (RSM) model was developed on this heterogeneous multi-source dataset, with W/B, A/B, SCM/B, FA/B, and GGBFS/B ratios as independent variables. The model showed strong significance (p < 0.0001, F = 426.89, R 2 = 0.95), with an average relative deviation of 6.2 %. A study-level leave-one-study-out cross-validation confirmed generalizability, yielding an out-of-study R 2 of 0.92 (RMSE = 5.50 MPa). Mixtures optimized for identical compressive strength were compared with the reference series via life cycle assessment and life cycle cost analysis (LCCA), using a functional unit of 1 m3 with the same final-age strength. The optimized mixtures achieved reductions of up to 24.9 % in energy consumption, 26.4 % in global warming potential, 21.4 % in acidification potential, and 8.6 % in waste generation, while LCCA revealed an average cost advantage of 8–12 % under the assumed Turkish price scenario. The findings show that this integrated, literature-driven approach offers a viable pathway for sustainable green concrete, delivering comparable mechanical performance alongside environmental and economic benefits.
A viable use of industrial by-products in developing sustainable and long-lasting concrete is crucial to achieving sustainability in our built environment. This study investigates the mechanical, durability, and environmental benefits of concrete made with date palm ash (DPA) and silica fume (SF) as partial cement replacements. Concrete mixtures were prepared with varying DPA percentages (20 % and 30 %) and ternary blends made with combined DPA and SF. Compressive strength, water absorption, water penetration depth, rapid chloride penetration test (RCPT), and environmental benefits were evaluated. Response surface methodology (RSM) was used to analyse the combined effects of DPA and SF. Results indicated that high individual DPA replacement reduced early-age compressive strength. However, the SF enhanced the later-age strength of PDA concrete. A reductions in water absorption, water penetration, and chloride ion penetrability were also observed, indicating improved performance. Also, RCPT was reduced by up to 60 % compared to the control mixture. The RSM analysis highlighted the dominant role of SF in enhancing durability. Furthermore, CO2 emissions were reduced from 501 kg CO2/m3 (control mix) to 400 kg CO2/m3 for the optimum ternary blend (25 % DPA + 5 % SF).
