Search Results (1,528)

The growing need for efficient and safe high-energy lithium-ion batteries (LIBs) in electric vehicles and grid storage necessitates advanced internal monitoring solutions. This work presents a comprehensive simulation model of a novel integrated optical sensor based on ethylene carbonate-filled photonic crystal fiber (EC-PCF). The proposed design synergistically combines a chirped fiber Bragg grating (FBG) and an extrinsic Fabry–Pérot interferometer (EFPI) on a multiplexed platform for the multifunctional sensing of refractive index (RI), temperature, strain, and pressure (via strain coupling) within LIBs. By matching the RI of the PCF cladding to the battery electrolyte using ethylene carbonate, the design maximizes light–matter interaction for exceptional RI sensitivity, while the cascaded EFPI enhances mechanical deformation detection beyond conventional FBG arrays. The simulation framework employs the Transfer Matrix Method with Gaussian apodization to model FBG reflectivity and the Airy formula for high-fidelity EFPI spectra, incorporating critical effects like stress-induced birefringence, Transverse Electric (TE)/Transverse Magnetic (TM) polarization modes, and wavelength dispersion across the 1540–1560 nm range. Robustness against fabrication variations and environmental noise is rigorously quantified through Monte Carlo simulations with Sobol sequences, predicting temperature sensitivities of ∼12 pm/°C, strain sensitivities of ∼1.10 pm/$\mathsf{\mu }$$\mathsf{\epsilon }$, and a remarkable RI sensitivity of ∼1200 nm/RIU. Validated against independent experimental data from instrumented battery cells, this model establishes a robust computational foundation for real-time battery monitoring and provides a critical design blueprint for future experimental realization and integration into advanced battery management systems. Full article

Nanoparticles (NPs) of noble metals such as gold have garnered significant attention due to their novel optical and catalytic properties, their theranostic properties, as they are biocompatible, and they attract considerable interest in a range of applications including targeted drug delivery. In this study, a fractional factorial design (FFD) is applied to systematically investigate the influence of key synthesis parameters (independent variables) at a low level (−1) and a high level (+1), including the reducing agent type (chitosan or trisodium citrate), concentration of reducing agent (10 to 40 mg), pH (3.5 to 8.5), temperature (60 to 100 °C), agitation time (5 to 15 min), and agitation speed (400 to 1200 rpm), on the dependent parameters—particle size and polydispersity index of gold nanoparticles (GNPs). The goal of this study was to provide a comprehensive understanding of the interplay between these parameters and their interaction effect on the characteristics of gold nanoparticles. A fractional factorial design allowed for efficient screening of the parameter space while minimizing the number of experiments required. The results demonstrated that pH, reducing agent, reducing agent–concentration, reducing agent–concentration of reducing agent–pH, and reducing agent–temperature interactions played significant roles in determining the particle size of the synthesized GNPs. Moreover, pH and reducing agent–concentration were identified as the major factors influencing the dispersity of the NPs. This study sheds light on the complex relationships between synthesis parameters and NP characteristics, offering an insight into the capacity for optimizing the synthesis process in order to tailor the desired properties of GNPs. The findings contribute to the growing field of NP synthesis and advance the understanding of the underlying mechanisms governing the formation of GNPs with specific size and dispersity characteristics. Full article

This research evaluates the stabilization of a clay collected from the northern expansion zone of Cartagena de Indias, Colombia. Laboratory analyses, including particle size distribution, Atterberg limits, compaction, specific gravity, and XRF/XRD, classified the soil as a highly plastic clay (CH) with moderate dispersivity, as confirmed by pinhole and crumb tests. The soil was treated with 3–9% lime, with and without the addition of NaCl (0% and 2%), and tested for unconfined compressive strength (q_u), small-strain stiffness (G_o), and microstructural properties under curing periods of 14 and 28 days at two compaction densities. Results showed that lime significantly improved mechanical behavior, while the inclusion of NaCl further enhanced q_u (up to 185%) and G_o (up to 3-fold), particularly at higher lime contents and curing times. Regression models demonstrated that both q_u and G_o follow power-type relationships with the porosity-to-lime index, with consistent exponents (−4.75 and −5.23, respectively) and high coefficients of determination (R² > 0.79). Normalization of the data yielded master curves with R² values above 0.90, confirming the robustness of the porosity-to-lime framework as a predictive tool. The G_o/q_u ratio obtained (3737.4) falls within the range reported for cemented geomaterials, reinforcing its relevance for comparative analysis. SEM observations revealed the transition from a porous, weakly aggregated structure to a dense matrix filled with C–S–H and C–A–H gels, corroborating the macro–micro correlation. Overall, the combined use of lime and NaCl effectively converts dispersive clays into non-dispersive, mechanically improved geomaterials, providing a practical and sustainable approach for stabilizing problematic coastal soils in tropical environments. Full article

This study reports on green-synthesized zinc oxide nanoparticles (ZnONPs), focusing on their physicochemical characterization, photocatalytic properties, and agricultural applications. Dynamic light scattering (DLS) analysis revealed a mean hydrodynamic diameter of 337.3 nm and a polydispersity index (PDI) of 0.400, indicating moderate polydispersity and nanoparticle aggregation, typical of biologically synthesized systems. High-resolution transmission electron microscopy (HR-TEM) showed predominantly spherical particles with an average diameter of ~28 nm, exhibiting slight agglomeration. Energy-dispersive X-ray spectroscopy (EDX) confirmed the elemental composition of zinc and oxygen, while X-ray diffraction (XRD) analysis identified a hexagonal wurtzite crystal structure with a dominant (002) plane and an average crystallite size of ~29 nm. Photoluminescence (PL) spectroscopy displayed a distinct near-band-edge emission at ~462 nm and a broad blue–green emission band (430–600 nm) with relatively low intensity. The ultraviolet–visible spectroscopy (UV–Vis) absorption spectrum of the synthesized ZnONPs exhibited a strong absorption peak at 372 nm, and the optical band gap was calculated as 2.67 eV using the Tauc method. Fourier-transform infrared spectroscopy (FTIR) analysis revealed both similarities and distinct differences to the pigeon extract, confirming the successful formation of nanoparticles. A prominent absorption band observed at 455 cm⁻¹ was assigned to Zn–O stretching vibrations. X-ray photoelectron spectroscopy (XPS) analysis showed that raw pigeon droppings contained no Zn signals, while their extract provided organic biomolecules for reduction and stabilization, and it confirmed Zn²⁺ species and Zn–O bonding in the synthesized ZnONPs. Photocatalytic degradation assays demonstrated the efficient removal of pollutants from sewage water, leading to significant reductions in total dissolved solids (TDS), chemical oxygen demand (COD), and total suspended solids (TSS). These results are consistent with reported values for ZnO-based photocatalytic systems, which achieve biochemical oxygen demand (BOD) levels below 2 mg/L and COD values around 11.8 mg/L. Subsequent reuse of treated water for irrigation yielded promising agronomic outcomes. Wheat and barley seeds exhibited 100% germination rates with ZnO NP-treated water, which were markedly higher than those obtained using chlorine-treated effluent (65–68%) and even the control (89–91%). After 21 days, root and shoot lengths under ZnO NP irrigation exceeded those of the control group by 30–50%, indicating enhanced seedling vigor. These findings demonstrate that biosynthesized ZnONPs represent a sustainable and multifunctional solution for wastewater remediation and agricultural enhancement, positioning them as a promising candidate for integration into green technologies that support sustainable urban development. Full article

Persistent scatterer (PS) pixel selection is crucial in the PS-InSAR technique, ensuring the quality and quantity of PS pixels for accurate deformation measurements. However, traditional methods like the amplitude dispersion index (ADI)-based method struggle to balance the quality and quantity of PS pixels. To adequately select high-quality PS pixels, and thus improve the deformation measurement performance of PS-InSAR, the multi-temporal feature extraction network (MFN) is constructed in this paper. The MFN combines the 3D U-Net and the convolutional long short-term memory (CLSTM) to achieve time-series analysis. Compared with traditional methods, the proposed MFN can fully extract the spatiotemporal characteristics of complex SAR images to improve PS pixel selection performance. The MFN was trained with datasets constructed by reliable PS pixels estimated by the ADI-based method with a low threshold using ∼350 time-series Sentinel-1A SAR images, which contain man-made objects, farmland, parkland, wood, desert, and waterbody areas. To test the validity of the MFN, a deformation measurement experiment was designed for Tongzhou District, Beijing, China with 38 SAR images obtained by Sentinel-1A. Moreover, the similar time-series interferometric pixel (STIP) index was introduced to evaluate the phase stability of selected PS pixels. The experimental results indicate a significant improvement in both the quality and quantity of selected PS pixels, as well as a higher deformation measurement accuracy, compared to the traditional ADI-based method. Full article

This study demonstrates the valorization of orange peel waste as a sustainable feedstock for the production of cellulose nanocrystals (CNCs). Compositional analysis revealed a cellulose content up to 10.0% in the raw material. After performing the alkaline/peroxide treatment, CNCs were isolated via acid hydrolysis. Different inorganic acids were compared, namely sulfuric, phosphoric, and hydrochloric acids at low molar concentrations. The resulting CNCs showed distinct morphological and physicochemical properties, with sulfuric acid treatment yielding the highest crystallinity index (TCI) of 0.86 under conditions of 3.0 mol/L, 80 °C, and 225 min. Additionally, the presence of sulfate or phosphate groups significantly influenced the thermal degradation behavior and the inorganic residue content in the obtained CNCs. Finally, the CNCs were successfully tested as co-initiator for lactide ring-opening polymerization. The results show that the molecular weights of the resulting polylactide varied depending on the CNC dispersion. This work supports the use of orange peel waste as a bio-source for CNC production and their potential application as a co-initiator in the synthesis of polyesters. Full article

To investigate the mechanism by which the rheological properties of drilling fluids affect the stability of the wellbore in brittle mud shale, this study systematically examines the influence of drilling fluids with different rheological properties on the hydration dispersion and rock strength of brittle mud shale through a series of laboratory experiments, including thermal rolling tests and uniaxial compressive strength tests on core samples. The results reveal that for weakly dispersible brittle mud shale, the rheological properties of drilling fluids have a minor effect on hydration dispersion, with rolling recovery rates consistently above 90%. However, the rheological properties of drilling fluids significantly influence the strength of brittle mud shale, and this effect is coupled with multiple factors, including rock fracture intensity index, soaking time, and confining pressure. Specifically, as the viscosity of the drilling fluid increases, the reduction in rock strength decreases; for instance, at 5 MPa confining pressure with an FII of 0.46, the strength reduction after 144 h was 69.8% in distilled water (from an initial 133.2 MPa to 40.2 MPa) compared to 36.3% with 3# drilling fluid (from 133.2 MPa to 88.7 MPa, with 100 mPa·s apparent viscosity). Both increased soaking time and confining pressure exacerbate the reduction in rock strength; a 5 MPa confining pressure, for example, caused an additional 60.9% strength reduction compared to 0 MPa for highly fractured samples (FII = 0.46) in distilled water after 144 h. Rocks with higher fracture intensity indices are more significantly affected by the rheological properties of drilling fluids. Based on the experimental results, this study proposes a strength attenuation model for brittle mud shale that considers the coupled effects of fracture intensity index, soaking time, and drilling fluid rheological properties. Additionally, the mechanism by which drilling fluid rheological properties influence the strength of brittle mud shale is analyzed, providing a theoretical basis for optimizing drilling fluid rheological parameters and enhancing the stability of wellbores in brittle mud shale formations. Full article

The development of a straightforward strategy for preparing organic fluorescent materials, fine-tuning white-light emission, and subsequently constructing white light-emitting diodes (LEDs) is of great significance. Herein, we report on the modulation of white-light emission and the fabrication of white LEDs using polyhedral oligomeric silsesquioxane (POSS)-based fluorescent hybrid porous polymers (HPPs) through simple physical blending. Two HPPs, namely HPP-1 and HPP-2, which emit blue and red light, respectively, were synthesized via the efficient Heck reactions of octavinylsilsesquioxane with 4,4′-dibromobiphenyl and 1,3,6,8-tetrabromopyrene. By physically doping of HPP-1 and HPP-2 in variable ratios in solvent suspensions, it was discovered that white-light emission is significantly influenced by the concentrations of the materials and the excitation wavelength. Similar findings were also observed in the solid-state physical doping. An ideal white light emission with a CIE coordinate of (0.33, 0.33) can be achieved when excited at 380 nm with a mass ratio of HPP-1 to HPP-2 of 1:2. Finally, the two HPPs were dispersed in polysiloxane matrices, and a white LED with a CIE coordinate of (0.42, 0.36) was obtained. The LED exhibited a color rendering index of up to 90 and a correlated color temperature of 2858 K, realizing warm white light emission. This simple and convenient white-light regulation strategy holds great promise for application in the development of novel white LEDs based on organic fluorescent porous materials. Full article

This study examined the temporal changes and dispersion of potential sources of the six criteria air pollutants, namely, particulate matter with an aerodynamic diameter of less than 2.5 and 10 μm (PM_2.5 and PM₁₀), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), carbon monoxide (CO), and ozone (O₃), in eastern Xinjiang, China, during the COVID-19 period in summer 2020 (16 July to 29 August ). Compared to the same periods in 2019 and 2021, the mean concentrations of all pollutants, except for SO₂ and O₃, and the air quality index (AQI) were lower in 2020 (relative changes: NO₂ 48.3–54.4%, PM₁₀ 35.8–49.6%, PM_2.5 19.3–43.5%, CO 16.5–34.8%, AQI 17.2–29.4%), which can be attributed to the reduced anthropogenic activities. Compared to the period before the lockdown in 2020 (16 June to 15 July), the mean NO₂ concentration showed the largest decrease during the lockdown (47.9%), followed by PM_2.5 (32.7%), PM₁₀ (37.6%), and CO (15.4%). In contrast, there were only minimal changes in O₃, with the mean concentrations falling slightly by 7.56%, and the mean concentration of SO₂ increased by 10.4%. The decrease in NO_x and the dry climate could have hindered O₃ formation, while vital industrial activities in eastern Xinjiang probably maintained SO₂ emissions. In the subsequent recovery period (30 August to 28 September), the mean NO₂ concentration increased the most at 59.3%, which was due to the rapid resumption of traffic-related emissions. During the lockdown in 2020, the diurnal profiles of PM_2.5, PM₁₀, NO₂, and CO concentrations showed lower peak concentrations in the morning (09:00–11:00) and evening (20:00–22:00), demonstrating a significant reduction in traffic-related emissions. The lower O₃ and higher SO₂ peak concentrations may have resulted from lower NO_x levels and higher electricity consumption due to the “stay-at-home” policy. The analysis of the distribution of potential sources showed that O₃ generally originated from widespread source areas, while the other pollutants mainly originated from local emissions. During the lockdown period, the source areas of PM_2.5 and PM₁₀ were more dispersed, with an enhanced contribution from long-range transport. Full article

The stability of ceramic suspensions is a key factor in the preparation and shaping of ceramic bodies. The presented work offers an experimental determination of ceramics suspensions stability using the LUMiSizer analytical centrifuge, focusing on kinetic behaviour using transmission profiles and instability indexes. Multiple ceramic systems comprising corundum, metakaolin, and zirconia suspensions were experimentally examined under varying solid contents, dispersant dosages, and additive concentrations. Results showed that highly loaded corundum suspensions with dispersant (Dolapix CE64) achieved excellent stability, with an instability index below 0.05. Compared to classical sedimentation tests, which are time-consuming and not highly sensitive, LUMiSizer offers a suitable alternative by guaranteeing correct kinetic data and instability indexes indicating suspension behaviour using centrifugal force. Comparisons of the LUMiSizer results and data obtained using the modified Stokes law confirmed increased terminal velocities in experiments with metakaolin suspensions, indicating the sensitivity of the centrifuge to the effect of dispersion medium shape. The influence of porogen (waste coffee grounds) on the stability of corundum suspensions was also investigated, followed by slip casting to create and characterize a ceramic body, confirming the possibility of shaping based on stability results. Furthermore, instability indices are suggested as a rapid, quantitative method for comparing system stability and as an auxiliary criterion to the rheological measurements. Optimal dispersant concentration for zirconia-based photocurable suspensions was identified as 8.5 wt.%, which minimized viscosity and, at the same time, assured maximal kinetic stability. Integrating the LUMiSizer analytical centrifuge with standard methods, including sedimentation tests and rheological measurements, highlights its value as a powerful tool for characterizing and optimizing ceramic suspensions. Full article

Background and Objectives: Obstructive sleep apnea syndrome (OSAS) and heart failure (HF) frequently coexist, amplifying cardiovascular risk through mechanisms involving chronic inflammation and autonomic dysfunction. This study investigates the impact of systemic inflammation, measured by the systemic immune-inflammation index (SII), and OSAS severity, assessed by the apnea–hypopnea index (AHI), on myocardial repolarization heterogeneity in patients with both conditions. Materials and Methods: In this retrospective study, 160 patients with HF and polysomnography-confirmed OSAS (AHI ≥ 5 events/h) were evaluated between January 2018 and November 2024. Patients were stratified by QT dispersion (QTd < 40 ms vs. ≥40 ms) to assess electrical heterogeneity. SII was calculated from neutrophil, platelet, and lymphocyte counts, and electrocardiographic markers (QTd, frontal QRS-T angle, T wave peak-to-end interval [TPEI]) were measured. Logistic regression and receiver operating characteristic (ROC) analyses were used to identify predictors of repolarization heterogeneity and ventricular arrhythmias. Results: Patients with QTd ≥ 40 ms (n = 78) exhibited higher SII (p < 0.001) and AHI (p < 0.001) compared to those with QTd < 40 ms (n = 82). SII and AHI independently predicted increased QTd in multivariate analysis (p = 0.01 and p < 0.001, respectively). ROC analysis identified SII ≥ 625.4 (sensitivity 73.1%, specificity 72%) and AHI ≥ 22.4 (sensitivity 79.5%, specificity 79.3%) as optimal cut-offs for predicting repolarization heterogeneity. SII, QTd, and TPEI were significantly associated with ventricular arrhythmias (p < 0.05). Patients with moderate-to-severe OSAS (AHI ≥ 15) had higher rates of ventricular tachyarrhythmias (17.8% vs. 5.7%, p = 0.03) and sudden cardiac death (9.3% vs. 1.9%, p = 0.05). Conclusions: Elevated SII and AHI are independent predictors of myocardial repolarization heterogeneity in patients with HF and OSAS, contributing to increased arrhythmic risk. These findings highlight the potential use of SII and AHI as accessible biomarkers for risk stratification, particularly in patients with a preserved ejection fraction, and underscore the need for targeted interventions to mitigate inflammation and OSAS severity. Full article

In metabolic syndrome, cardiomyocyte changes induced by metabolic and proinflammatory factors impair repolarization and exacerbate the heterogeneity of the transmural dispersion of repolarization, and this is proarrhythmogenic. Limited data in the literature on the capabilities of speckle tracking echocardiography for assessing proarrhythmogenicity in metabolic syndrome exists. 71 patients with newly diagnosed metabolic syndrome, aged 35–55 years, were studied. Ischemic heart disease was excluded in all patients with stress test cycle ergometry, CT-angiography or selective coronary angiography. All patients underwent a 48-h Holter ECG recording. Based on the latter, they were divided into two groups: 38 patients (53.5%) with a high arrhythmogenic load (supraventricular or ventricular tachycardia, atrial fibrillation/flutter, ventricular extrasystoles over 10%, frequent supraventricular extrasystoles > 500/24 h are included); and 33 patients (46.5%) with low arrhythmogenic load (no significant rhythm disturbances are included). Echocardiography was performed with a GE Vivid T9 emphasizing global longitudinal strain, mechanical dispersion index and left atrium strains. Statistically significant differences in the global longitudinal strain, mechanical dispersion index, and left atrium strain were found between the group with low arrhythmogenicity and the group with high arrhythmogenicity (p < 0.0001). The index of mechanical dispersion has the most optimal sensitivity and specificity of all investigated echocardiographic markers. These results support the mechanical dispersion index as an additional tool for assessing proarrhythmogenicity in metabolic syndrome. Full article

The development of lightweight, high-damping building materials is critical for enhancing the seismic resilience of civil infrastructure. This study introduces a novel approach to synergistically improve the damping and mechanical properties of cementitious composites by incorporating one-dimensional carbon nanotubes (CNTs) or two-dimensional graphene nanoplatelets (GNPs). The novelty lies in (1) a direct comparison of 1D versus 2D carbon nanomaterials efficacy within a vibration-relevant frequency range (0.5–2 Hz); (2) the use of the Ca(OH)₂ orientation index, derived from X-ray diffraction (XRD), to link microstructural texturing with macroscopic dynamic performance; and (3) establishing clear mechanistic link between carbon nanomaterials dispersion, pore structure evolution, and the resultant balance between stiffness and damping. Dynamic mechanical analysis identified an optimal dosage of 0.1% by weight for both nanomaterials. Comprehensive microstructural characterization (SEM, MIP, XRD, TGA/DTG) revealed that the carbon nanomaterials act as nucleation sites, promoting cement hydration and refining the pore structure. This structural enhancement concurrently improved mechanical strength and energy dissipation capacity. The primary damping mechanism was identified as interfacial friction and slippage at the nanofiller–matrix interface. These findings provide fundamental insights for the rational design of high-performance cementitious composites and offer an evidence-based pathway for creating advanced seismic-resistant materials. Full article

Mercury (Hg) pollution from artisanal and small-scale gold mining (ASGM) is a global environmental and public health concern. In Indonesia, ASGM remains widespread, yet assessments of multimedia contamination and health risks are limited. This study quantified Hg concentration in water, sediment, soil, fish, and cassava to evaluate environmental pollution and potential health risks in Waluran, Sukabumi, Indonesia. Mercury concentration in ASGM was higher than in the reference area, especially in fish (median: 4.76 mg/kg dw), cassava leaves (median: 15.7 mg/kg dw), and tailing sediments (median: 171 mg/kg dw). A remarkably high Hg concentration (9760 mg/kg dw) was detected in soil from amalgam-burning spots. An elevated Hg concentration was observed in the reference area, suggesting widespread contamination and potential for long-range dispersion. Over 85% of ASGM samples were categorized as heavily to extremely contaminated by the geo-accumulation index (I_geo). Bioaccumulation assessment indicated a high bioconcentration factor (BCF) in fish and moderate bioaccumulation factor (BAF) in cassava roots. Hazard Quotients (HQ) were greater than 1 for most exposure pathways in both adults and children, with the greatest risk deriving from cassava leaf consumption. These findings indicate severe Hg contamination within ASGM-affected communities and underscore the urgent need for public health interventions, environmental monitoring, and strengthened regulations to reduce Hg exposure in Indonesia. Full article

In order to investigate the compression damage characteristics of the “interface section coal pillar–backfill body (ICPF)” composite structure formed after coal pillar excavation and gangue material backfill in the key technologies of coal pillar excavation and gangue material backfill replacement in the interface section of thick coal seams, an ICPF single-axis compression damage experiment under different internal dimensions of backfill was conducted using the PFC^2D numerical model, with the interface section coal pillar of a working face at a certain mine in northern Shaanxi Province as the research background. In addition, the stress–strain state, peak strength characteristics, damage mode, energy evolution, and damage characteristics of the ICPF composite were analyzed, and models for the evolution of the ICPF elastic modulus and compressive strength were established. The results showed that the stress–strain state of the ICPF changed from brittle to ductile as backfill strength decreased. The distribution of the elastic modulus is primarily influenced by backfill strength, and as the excavation–backfill width increases, the curve exhibits a distinct S-shaped distribution. The compressive strength decreases by up to 63.4% with an increase in excavation–backfill width and by up to 65.1% with a decrease in backfill strength. The sensitivity of compressive strength to backfill strength is greater than that to excavation–backfill width. Based on the established ICPF elastic modulus and compressive strength evolution model, the two mechanical properties were compared using model fitting, and the model fitting results were satisfactory. The ICPF exhibits three types of damage characteristics as the excavation and backfill width increases: oblique shear and tensile damage, edge coal stripping and X-shaped conjugate damage of the backfill body, and large-area plastic damage of the backfill body. By establishing a theoretical damage variable based on linear dissipation energy, damage factors can be quickly obtained from stress–strain curves. The damage curves all exhibit exponential growth, and their growth rates show certain dispersion as the excavation and backfill width increases and backfill strength decreases. Based on the brittleness index analysis of the ICPF composite, as the backfill strength decreases and excavation and backfill width increases, the brittleness index of the composite increases, and the tendency for impact increases. At an excavation and backfill width of 80 mm, rib damage tends to happen. Full article