Search Results (218)

Municipal solid waste incineration generates by-products like nitrogen oxides, sulfur dioxide, and hydrogen chloride, contributing to environmental issues such as acid rain, ozone depletion, and photochemical smog. While industrial sites use desulfurization and denitrification to reduce emissions, no studies have modeled the formation mechanisms and influencing factors of these pollutants from a pollution reduction perspective. This study first analyzes the municipal solid waste incineration process to identify the main factors affecting the concentration of pollutants related to desulfurization and denitrification. A coupled numerical simulation model for the whole life cycle desulfurization and denitrification process in real municipal solid waste incineration power plants is then constructed using a method that couples two software tools. Next, based on a double orthogonal experimental design, virtual simulation data are generated using the numerical simulation model. Finally, an improved interval type-II fuzzy broad learning algorithm is applied to construct a mechanism model for the whole process of desulfurization and denitrification-related pollutant concentration, using the obtained virtual simulated data. Using a Beijing incineration plant as a case study, the whole life cycle model is successfully established. The research provides data for optimizing pollutant reduction, examines influencing factors, and lays the groundwork for future intelligent control. Full article

The therapeutic use of non-steroidal anti-inflammatory drugs (NSAIDs) is limited by gastrointestinal and renal adverse effects caused by non-selective COX-1 and COX-2 inhibition. To address this issue, a new series of naproxen–azetidinone hybrids was rationally designed and synthesized to enhance COX-2 selectivity and reduce off-target toxicity. The synthesis involved esterification, hydrazide formation, Schiff base condensation, and intramolecular cyclization with chloroacetyl chloride. Structural characterization was achieved through FT-IR, ¹H NMR, and ¹³C NMR analyses. In silico ADMET profiling confirmed compliance with Lipinski’s rule and predicted favorable gastrointestinal absorption. Molecular docking revealed high COX-2 binding affinities (−11.93 to −9.72 kcal/mol), while MM/GBSA analysis identified compound N4_c (ΔG = −62.27 kcal/mol) as the most stable complex, surpassing meloxicam and naproxen. DFT (B3LYP/6-31G(d,p)) frontier molecular orbital analysis indicated a narrow HOMO–LUMO gap (ΔE = 2.97 eV) for N4_c, suggesting high electronic reactivity and strong enzyme interaction. Molecular dynamics simulations confirmed complex stability. In vivo anti-inflammatory testing using an egg-white-induced rat paw edema model showed that N4_d, N4_e, and N4_f achieved higher inhibition (19.22%, 16.98%, and 16.98%) than naproxen (4.3%). These results highlight 2-azetidinone–naproxen hybrids as promising selective COX-2 inhibitors with enhanced pharmacokinetic and electronic properties. Full article

The accurate prediction of the mechanical behaviour of silica–epoxy nanocomposites is essential for advancing their application in high-performance industries, including aerospace, automotive, and structural engineering. Conventional experimental characterization methods are often time-consuming and costly, highlighting the need for efficrelianceient computational alternatives. This study proposes a machine learning based on Random Forest Regression to predict the stress–strain behaviour of silica–epoxy nanocomposites with high accuracy. The model employs two independent and physically meaningful input parameters—SiO₂ nanoparticle concentration (wt%) and strain—to predict stress, thereby capturing the true constitutive relationship of the material. The model was trained and validated on an extensive experimental dataset of 7422 observations across five compositions (0–4 wt% SiO₂), obtained from systematic tensile testing following the ASTM D638 standard. Rigorous stratified 10-fold cross-validation confirmed excellent generalization (mean R² = 0.9977 ± 0.0023) with minimal overfitting (training–validation gap < 0.005). The performance of the test set (R² = 0.9948, mean absolute error (MAE) = 0.0404 MPa) surpasses recent literature benchmarks by nearly 5%, establishing state-of-the-art accuracy in nanocomposite property prediction. Error analysis revealed stable prediction accuracy throughout the elastic and plastic regimes (error variance < 0.004 MPa² for strain), with a physically consistent increase in error near failure due to complex damage mechanisms. Feature importance analysis indicated that strain and SiO₂ concentration contributed 78.4% and 21.6%, respectively, to predictive accuracy. This is consistent with constitutive modelling principles, in which deformation state primarily determines stress magnitude, while composition modulates the functional relationship. Mechanical property extraction from experimental curves showed optimal performance at 2–3 wt% SiO₂, yielding balanced enhancements in tensile strength (+1–2%) and failure strain (+36–64%) relative to neat epoxy. The validated framework reduces material development time by 65–80% and cost by 60–75% compared with conventional trial-and-error methods, offering a robust, data-driven tool for the efficient design and optimization of silica–epoxy nanocomposites. A comprehensive discussion of limitations and applicability boundaries ensures the framework’s responsible and reliable deployment in engineering practice. Full article

The lack of freshwater and the low efficiency of the traditional solar stills have led to the search to find a technology that can enhance desalination by use of vacuum-enhanced solar still technology. This review intends to investigate the impact of integrating a vacuum into solar stills, which include vacuum membrane distillation (VMD), nanoparticle-enhanced solar stills, multi-effect/tubular solar stills, geothermal integration and parabolic concentrator solar stills. The most important findings show that the productivity improves greatly: vacuum-assisted solar stills give up to 133.6% more product using Cu₂O nanoparticles, and multi-effect tubular stills under vacuum (40−60 kPa) show a doubling in freshwater productivity (7.15 kg/m²) in comparison to atmospheric operation. Geothermal cooling and vacuum pump systems show a 305% increase in productivity, and submerged VMD reached 5.9 to 11.1 kg m⁻² h⁻¹ with solar heating. Passive vacuum designs further reduce the energy used down to a specific cost, using as little as USD 0.0113/kg. Nevertheless, membrane fouling, initial cost, and the complexity of the system can still be termed as the challenges. This review highlights the significance of vacuum-enhanced solar stills to address the critical issue of freshwater scarcity in arid regions. The integration of vacuum membrane distillation, nanoparticle and heat recovery into vacuum-enhanced solar stills enabled us to improve the economic feasibility. We conclude that vacuum technologies significantly boost the efficiency and economic feasibility of solar desalination as a potential approach to sustainable desalination. Specifically, these inventions will contribute to providing a renewable and cost-effective solution for freshwater production. Further investigations are required to overcome the existing challenges, such as system complexity and membrane fouling, to effusively comprehend the efficacy of vacuum-enhanced solar stills to ensure sustainable water management. Full article

Background: Numerous healthcare services have been affected by the COVID-19 pandemic worldwide. Specialized healthcare services were postponed or canceled, potentially compromising regular services for hemato-oncology patients. The current study aimed to analyze the impact of the COVID-19 pandemic on access to hemato-oncology services in Almaty, the largest city in Kazakhstan. Methods: We retrospectively analyzed the socio-demographic characteristics of patients admitted to two large tertiary centers rendering hemato-oncology services, the City Clinical Hospital 7 (H7) and the Kazakh Institute of Oncology and Radiology (KazIOR). All data were retrieved for the period spanning from 1 March 2019 to 28 February 2022. The retrieved variables included age, gender, type of residence, hospitalization rate, treatment outcomes (discharged/deceased), bed days, diagnoses according to International Classification of Diseases (ICD-10) (acute leukemia and hematopoietic depression, lymphoproliferative diseases, and myeloproliferative diseases), and referral sources (ambulance, another hospital, consultative and diagnostic assistance, primary healthcare, self-referral, and referrals from hematologists’ offices). Results: In the 2019–2022 period, 6763 hemato-oncology hospitalizations were registered: 3583 in H7 and 3180 in KazIOR. The mean age at hospitalization was 55.04 (SD = 16.07) for females and 51.2 (SD = 16.7) for males. The proportion of hospitalized urban and rural patients differed significantly: 6191 (92%) and 571 (8,4%), respectively (χ² = 13.8, p = 0.001). In the 2020–2021 period, fewer patients were discharged (n = 2047) compared to 2019–2020 (n = 2387) and 2021–2022 (n = 2081) (χ² = 20.09, p = 0.003). However, the proportion of deaths in the 2020–2021 period (3.5%) was higher than in the 2019–2020 (3.2%) and 2021–2022 periods (2.6%) (χ² = 20.09, p = 0.003). A total of 403 (19%) hospital admissions were carried out by ambulance (emergency cases) in the 2020–2021 period, 368 (14.8%) in 2019–2020, and 394 (18.3%) in 2021–2022 (χ² = 2231, p < 0.001). The number of patients transferred from other hospitals to H7 and KazIOR increased by 12.4% in the 2020–2021 period. Conclusions: Our findings indicate a negative impact of the COVID-19 pandemic on access to hemato-oncology services, leading to increased mortality. Further studies are warranted to explore factors underlying the trends in hospitalizations and mortality of hemato-oncology patients during healthcare crises. Full article

This study investigates the structural behavior of composite double-web steel beams filled with different types of concrete made from a combination of recycled concrete aggregates and normal aggregates. The research includes both experimental and numerical analyses. Seven specimens were tested under symmetrical two-point loading, all having identical geometric properties: a span length of 1100 mm, flange plates 120 mm wide and 6 mm thick, and web plates 3 mm thick and 188 mm deep. The specimens were divided into two groups, with a control beam without concrete infill. Group one included beams filled with normal concrete in different locations (middle region, two sides, and fully filled), while group two mirrored the same fill locations but used recycled concrete instead. The experimental results showed that using normal concrete improved the ultimate load by 10.19% to 55.30%, with the fully filled beam achieving a maximum increase in ductility of about 568% and a stiffness improvement ranging from 2.6% to 39% compared to the control beam. Beams filled with recycled concrete showed increases in ultimate load from 9.52% to 42.03%, ductility improvements of up to 380%, and stiffness enhancements between 4.5% and 8.03%. Numerical modeling using ABAQUS (2021) showed excellent agreement with the experimental results, with differences in ultimate load and maximum deflection averaging 5.5% and 7.9%, respectively. Full article

Introduction: Hospital-acquired infections remain a significant healthcare concern due to the persistence of pathogens such as Staphylococcus aureus and Escherichia coli on frequently touched surfaces. Conventional TiO₂ coatings are limited to UV activation, which restricts their application under normal indoor light. Combining TiO₂ with ZnO and employing green synthesis methods may overcome these limitations. Methodology: Biogenic TiO₂ and ZnO nanoparticles were synthesized using Bacillus subtilis under mild aqueous conditions. The nanoparticles were characterized by SEM, XRD, UV-Vis, and FTIR, confirming nanoscale size, crystalline phases, and organic capping. A multilayer TiO₂/ZnO coating was fabricated on glass substrates through layer-by-layer deposition. Antibacterial activity was tested against S. aureus and E. coli using disk diffusion, direct contact assays, ROS quantification (FOX assay), and scavenger experiments. Statistical significance was evaluated using ANOVA. Results: The TiO₂/ZnO multilayer exhibited superior antibacterial activity under visible light, with inhibition zones of ~15 mm (S. aureus) and ~12 mm (E. coli), significantly outperforming single-component coatings. Direct contact assays confirmed strong bactericidal effects, while scavenger tests verified ROS-mediated mechanisms. FOX assays detected elevated H₂O₂ generation, correlating with antibacterial performance. Discussion: Synergistic effects of band-gap narrowing, Zn²⁺ release, and ROS generation enhanced visible-light photocatalysis. The multilayer structure improved light absorption and charge separation, providing higher antimicrobial efficacy than individual oxides. Conclusion: Biogenic TiO₂/ZnO multilayers represent a sustainable, visible-light-activated antimicrobial strategy with strong potential for reducing nosocomial infections on hospital surfaces and surgical instruments. Future studies should assess long-term durability and clinical safety. Full article

Objectives: The current work aimed to formulate and optimize a self-emulsifying microemulsion drug delivery system (SEME) for acemetacin (ACM) to increase ACM’s aqueous solubility, improve oral bioavailability, and reduce gastrointestinal complications. Methods: Screening of components capable of enhancing ACM solubility was performed. Pseudo-ternary phase diagrams were performed to choose the optimal formulation ratio. The ACM-SEME formulation’s composition was optimized using D-optimal design. Oil, S_mix, and water percentages were used as independent variables, while globule size, polydispersity index, ACM content, and in vitro ACM release after 90 min were used as dependent variables. Also, thermodynamic stability and transmittance percentage tests were studied. Zeta potential was assessed for the optimized ACM-SEME formulation, which was then subjected to spray drying. The dried ACM-SEME was characterized using field-emission scanning electron microscope, Fourier-transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry. The dried ACM-SEME formulation was filled into hard gelatin capsules and coated with Eudragit L100 to achieve pH-dependent release. Results: The antinociceptive activity of ACM-SEME was evaluated in vivo using Eddy’s hot plate test in rats, revealing a significant prolongation of the noxious time threshold compared to control groups. Ex vivo permeation studies across rat intestinal tissue confirmed the enhanced permeation potential of the ACM-SEME. Conclusions: It was concluded that the developed ACM-SEME system demonstrated improved physicochemical properties, enhanced release behavior, and superior therapeutic performance, highlighting its potential as a safer and more effective oral delivery platform for ACM. Full article

This research investigates the influence of incorporating perlite aggregate and silica fume on the properties of cement mortar, with a focus on compressive strength, flexural strength, density, water absorption, and thermal conductivity. The results show that increasing the percentage of perlite (Pe) in the mixes causes a marked reduction in the compressive strength, reflecting the lightweight nature and low density of perlite. For mixes with Pe-20% through Pe-100%, the compressive strength decreased by up to 78% compared to the reference mix. However, the addition of silica fume (SF) in mixes with SF-20% to SF-100% partially offset this effect, limiting the strength losses to 18–71%, which indicates that silica fume contributes to strength enhancement over time. The flexural strength followed a similar trend, decreasing with a higher perlite content: reductions of up to 40% were observed for Pe mixtures, while SF mixes showed slightly smaller decreases, reaching 36%. The density also declined consistently with increasing perlite replacement, with a maximum reduction of 57% in mix Pe-100% due to the inherent porosity of perlite. The water absorption increased substantially in the same mix (Pe-100%), by 327% compared to the reference one, whereas the addition of silica fume (SF-100%) limited the increase to 181%, confirming its role in refining the pore structure. The thermal conductivity decreased with a higher perlite content, attributed to the formation of voids in the matrix. The lowest value was observed for Pe-100%, with an 82% reduction, while silica fume mixes also showed reductions of 37–81% relative to the reference mix. Based on a comprehensive evaluation of strength, density, water absorption, and thermal performance, mix SF-60% was identified as the optimal mixture, offering a balanced profile with a compressive strength of 4.4 MPa, thermal conductivity of 0.28 W/(m·K), and density of 1089 kg/m³. These performance levels make the developed mortars particularly suitable for non-load-bearing masonry units, lightweight blocks, and insulation panels, where reduced weight and enhanced thermal efficiency are essential. The study therefore provides practical guidance for the design of sustainable, lightweight mortars for energy-efficient construction applications. Full article

We present a systematic study on the fabrication of gold nanoislands by microwave-assisted annealing, a rapid and energy-efficient alternative to conventional thermal treatments. Gold thin films with nominal thicknesses of 4, 5, 6, 8, and 10 nm are deposited by thermal evaporation directly onto BK7 glass substrates, with and without a 3 nm chromium adhesion layer. The samples are subsequently annealed in a microwave kiln, where microwave irradiation is absorbed and converted to heat within the graphite-coated cavity (kiln), allowing the substrate temperature to exceed 550 °C, the threshold required for film dewetting. This process induces a controlled morphological evolution from continuous thin films to well-defined nanoislands, with the final size distribution strongly dependent on the initial film thickness. Compared with oven-based annealing, microwave treatment promotes faster and more uniform heating, which enhances atomic diffusion and accelerates dewetting while reducing the risk of substrate deformation or excessive coalescence. The resulting nanoislands exhibit tailored size-dependent plasmonic properties, with clear correlations between film thickness, crystallite size, and optical absorption features. Importantly, the method is cost-efficient, requiring shorter processing times and lower energy input, while enabling reproducible fabrication of high-quality plasmonic nanostructures on inexpensive glass substrates, suitable for applications in sensing, photonics, and nanophotonics. Full article

The use of hot mix asphalt (HMA) has several drawbacks, such as the emission of harmful gases into the atmosphere, difficulties in maintaining temperature over long distances, and the requirement for high energy consumption during preparation and installation. In order to solve these issues, this research aimed to produce High-Performance Cold Mix Asphalt (HP-CMA), in which Ordinary Portland Cement (OPC) is used as a filler to replace limestone filler at 0%, 1.5%, 3%, 4.5%, and 6% of the aggregate weight. Indirect Tensile Stiffness Modulus (ITSM), moisture susceptibility, temperature susceptibility, and microstructural analysis tests were carried out. The results showed that the ITSM was considerably enhanced when OPC was utilized. When comparing HP-CMA with 3% OPC to the control HMA (100–150 pen), the ITSM increased by approximately 80% after three days. In contrast, HP-CMA with 4.5% OPC achieved the same ITSM as the control HMA (40–60 pen) after seven days. Moreover, the ITSM of the HMA 40–60 pen decreased by 91.93% when the temperature rose from 20 °C to 45 °C, whereas the ITSM of the HP-CMA with 6% OPC decreased by 42.47% over the same temperature range. This suggests that HP-CMA is more stable than the HMA 40–60 pen at elevated temperatures. The superior performance of the HP-CMA can be attributed to two essential factors: the improved binding effect due to the demulsification of the asphalt emulsion used as a binder, and the formation of hydration products from the added cement. Full article

Rainwater harvesting for sustainable agriculture (RWHSA) offers a viable and eco-friendly strategy to alleviate water scarcity in semi-arid regions, particularly for agricultural use. This study aims to identify optimal sites for implementing RWH systems in northern Iraq to enhance water availability and promote sustainable farming practices. An integrated geospatial approach was adopted, combining Remote Sensing (RS), Geographic Information Systems (GIS), and Multi-Criteria Decision Analysis (MCDA). Key thematic layers, including soil type, land use/land cover, slope, and drainage density were processed in a GIS environment to model runoff potential. The Soil Conservation Service Curve Number (SCS-CN) method was used to estimate surface runoff. Criteria were weighted using the Analytical Hierarchy Process (AHP), enabling a structured and consistent evaluation of site suitability. The resulting suitability map classifies the region into four categories: very high suitability (10.2%), high (26.6%), moderate (40.4%), and low (22.8%). The integration of RS, GIS, AHP, and MCDA proved effective for strategic RWH site selection, supporting cost-efficient, sustainable, and data-driven agricultural planning in water-stressed environments. Full article

This study investigates the influence of varying water-to-cement (W/C) ratios and fine aggregate compositions on the performance of concrete incorporating expanded perlite aggregate (EPA) as a lightweight alternative to natural sand. A total of eighteen concrete mixes were produced, each with different W/C ratios and fine-to-coarse aggregate (FA/CA) ratios, and evaluated for workability, compressive strength, flexural and tensile strength, water absorption, density, and thermal conductivity. Perlite was used to fully replace natural sand in half of the mixes, allowing a direct assessment of its effects across low-, medium-, and high-strength concrete formulations. The results demonstrate that EPA can improve workability and reduce both density and thermal conductivity, with variable impacts on mechanical performance depending on the W/C and FA/CA ratios. Notably, higher cement contents enhanced the internal curing effect of perlite, while lower-strength mixes experienced a reduction in compressive strength when perlite was used. These findings suggest that expanded perlite can be effectively applied in structural and non-structural concrete with optimized mix designs, supporting the development of lightweight, thermally efficient concretes. Mixture W16-100%EPS was considered the ideal mix because its compressive strength at the age of 65 days 44.2 MPa and the reduction in compressive strength compared to the reference mix 14% and the reduction in density 5.4% compared with the reference mix and the reduction in thermal conductivity 14% compared with the reference mix. Full article

As the demand for energy-efficient homes continues to rise, the importance of advanced mechanical ventilation systems in maintaining indoor air quality (IAQ) has become increasingly evident. However, challenges related to energy balance, IAQ, and occupant thermal comfort persist. This review examines the performance of mechanical ventilation systems in regulating indoor climate, improving air quality, and minimising energy consumption. The findings indicate that demand-controlled ventilation (DCV) can enhance energy efficiency by up to 88% while maintaining CO₂ concentrations below 1000 ppm during 76% of the occupancy period. Heat recovery systems achieve efficiencies of nearly 90%, leading to a reduction in heating energy consumption by approximately 19%. Studies also show that employing mechanical rather than natural ventilation in schools lowers CO₂ levels by 20–30%. Nevertheless, occupant misuse or poorly designed systems can result in CO₂ concentrations exceeding 1600 ppm in residential environments. Hybrid ventilation systems have demonstrated improved thermal comfort, with predicted mean vote (PMV) values ranging from –0.41 to 0.37 when radiant heating is utilized. Despite ongoing technological advancements, issues such as system durability, user acceptance, and adaptability across climate zones remain. Smart, personalized ventilation strategies supported by modern control algorithms and continuous monitoring are essential for the development of resilient and health-promoting buildings. Future research should prioritize the integration of renewable energy sources and adaptive ventilation controls to further optimise system performance. Full article

With increasing traffic loads and the continuous deterioration of asphalt pavements, it has become necessary to explore alternative materials that enhance both performance and sustainability. This study aims to investigate the effect of using cement kiln dust (CKD) as a filler substitute in hot mix asphalt composites, focusing on the mechanical and durability properties of pavements. The results indicate that replacing conventional filler with CKD in different proportions (1.5%, 3%, 4.5%, and 6%) positively affects the properties of asphalt mixtures. Marshall stability values increased by 58.4% when using 100% CKD, indicating a significant improvement in the mixture’s ability to withstand traffic loads. Flow tests revealed that replacing CKD by up to 50% enhances the flexibility of the mixture, but exceeding this percentage makes the mixture stiffer, which may lead to premature cracking. In terms of moisture sensitivity, incorporating CKD by 25% improves the mixture’s resistance to water damage, while increasing it to 100% reduces this resistance, highlighting the need to improve the adhesion properties of asphalt. Indirect tensile strength tests have confirmed that CKD enhances the cohesion of the mixture, reducing the likelihood of cracking under pressure and contributing to longer pavement life. Based on these results, it is recommended that CKD be used for up to 50% to achieve a balanced combination of strength, flexibility, and moisture resistance, with further studies being needed to evaluate the long-term performance and potential improvements through additional material modifications. Full article