Objective This study aims to compare the detectability index (d′) between the human observer (HO) and advanced model observer (AMO) using the Non-Prewhitening Observer (NPW) and Non-Prewhitening Observer with Eye Filter (NPWE) for various tube currents and low-contrast objects. Methods Image data were obtained using the ACR 464 phantom at three different tube current levels (i.e., 80 mA, 140 mA, and 200 mA). The task object had contrast levels ranging from 3 HU to 15 HU, with a diameter of 3 mm. The task objects used a Gaussian profile model. The d′ values were measured using the AMO with NPW and NPWE models, while HO values were computed using the 2-AFC method. Each configuration consisted of 100 signal-present and 100 signal-absent images. Results The results demonstrated that the d′ values obtained from AMO displayed a trend similar to those derived from HO. Increases in the tube current and contrast resulted in higher d′ values across all observers. Correlation analysis revealed that NPW and NPWE showed a strong relationship with HO (r = 0.979; p < 0.001) and (r = 0.976; p < 0.001), respectively. Conclusion This study confirms that the AMO can effectively replicate object detection with accuracy comparable to that of HO. This behaviour was consistently observed across variations in tube current and low-contrast objects.
Poly (vinylidene fluoride‑co‑hexafluoropropylene) (PVDF‑HFP) polymer inclusion membranes (PIMs) are widely used across separation industries because of their ability to selectively separate ions or molecules, their chemical stability, and their mechanical flexibility. Still, improving how the membrane performs without making the membrane material properties deteriorate remains a challenge. In this study, Aliquat 336 and Cyphos IL 104 were blended with PVDF‑HFP and fabricated through the solvent casting method. The main objective of this study is to understand how the ionic liquids can affect the membrane’s chemical properties, physical properties, mechanical stability, and its ability to recover gold through an H-cell setup. FTIR analysis confirmed the presence of Aliquat 336, showing bands associated with quaternary ammonium groups, while Cyphos IL 104 displayed vibrations related to phosphonium‑related P–C. SEM images further revealed clear differences in how the membrane morphology looked. Pure PVDF-HFP alone had compact surfaces; Aliquat 336 membranes appeared to have smoother features, and Cyphos IL 104 membranes developed rougher surfaces with micro-voids. The addition of ionic liquids also increased membrane porosity from 25 % in the pure membrane to 45 % with the addition of ionic liquids. At the same time, the contact angle dropped from 90° to 58°, indicating improved hydrophilicity. Mechanical testing showed that pure PVDF‑HFP had the highest tensile strength (30 MPa), modulus (450 MPa), and tear resistance (2.5 N/mm). Membranes with higher Aliquat 336 content retained better tear resistance, close to 2.0 N/mm, while maintaining smoother membrane surfaces. In comparison, the addition of Cyphos IL 104 adversely impacts the mechanical properties. Gold extraction experiments showed promising performance. The PVDF-HFP/A15C20 membrane achieved 76 % recovery within 12 h. The combination of both Aliquat 336 and Cyphos IL 104 improved ion transport while maintaining acceptable membrane stability properties. Overall, the results showed that the ionic liquid composition has a strong influence on both the membrane’s durability properties and separation performance. These findings provide a useful approach for developing membranes in precious metal recovery applications.
The research evaluated the precision and reliability of the open-source software FIJI (Fiji Is Just ImageJ) as a novel tool for analyzing images from an Optical Gas Imaging (OGI) camera to quantify emissions. The FIJI software was validated against an extinguisher's traditional gravimetric method during controlled CO2 release experiments. The results from the gravimetric method are regarded as a benchmark for comparison with those obtained using the FIJI-based method to validate the consistency of the FIJI method. Following the reliability assessment of the FIJI-based approach, the technique was applied to estimate fugitive methane emissions in the Zubair oil field. Subsequently, its robustness was evaluated under simulated environmental variations, including temperature and wind speed changes based on the Environmental Protection Agency (EPA), Other Test Method (OTM) 33A. Temperature variations (20 degrees C vs. 40 degrees C) resulted in a modest 3% reduction in mass flow rate measurements at the higher temperature, while maintaining a near-perfect agreement (r = 1.0000). Wind speed variations (2 m/s, 5 m/s, and 10 m/s) demonstrated exceptional robustness, with negligible changes in measurements (ranging from 0.000069% to 0.000305%) and near-perfect correlation coefficients. These findings confirm that the FIJI-based method is a promising and reliable tool for methane quantification under typical field conditions, showing limited sensitivity to environmental changes across all tested simulated scenarios. The originality of this work lies in addressing a critical gap in the accurate quantification of fugitive methane emissions through the adoption of an open-source, accessible image analysis platform. However, the field application was not validated against independent methane concentration measurements. Field validation is crucial to confirm the accuracy of the proposed workflow.
An efficient activation strategy for peracetic acid (PAA)-based advanced oxidation processes (AOPs) is highly desirable for environmental remediation. Herein, we report a novel CoNi alloy embedded in N-doped carbon (NCCoNi) derived from a nitrogen-rich cyano-coordination framework as an efficient heterogeneous catalyst for activating a system composed of tetraacetylethylenediamine (TAED) and sodium percarbonate (SPC), which enables the in-situ generation of PAA. The unique architecture integrates uniformly dispersed CoNi alloy nano-particles with a conductive N-doped carbon (NC) matrix. The NCCoNi catalyst exhibits significantly superior catalytic performance compared to commercial Co3O4 and NiO, NCCo, NCNi, and NC. This enhancement originates from CoNi alloying and the synergistic electronic interaction between CoNi alloy and NC, rather than surface area alone. Mechanistic investigations combining DFT calculations, EPR and electrochemical analyses reveal that the oxidation process proceeds through the combined effect of singlet oxygen (1O2), superoxide oxygen (O2 center dot-), and electron transfer pathway. As a representative azo toxicant, Orange II was employed to evaluate the system performance. Its azo linkage and adjacent aromatic carbons are identified as the primary reactive sites. Importantly, this work demonstrates the potential of CoNi alloy for SPC/TAED activation and provides a representative application of this system for azo dye degradation, offering new insights into alloy-carbon synergy for sustainable AOPs.
This study presents the synthesis, structural architecture, density functional theory (DFT) investigations, third-order nonlinear optical (NLO) properties, and biological evaluations of two organic-inorganic hybrid compounds based on the dicationic 1-(4-pyridyl)piperazine ligand: (C9H15N3)2+.HgCl42-(Compound I) and (C9H15N3)2+.CuCl42-(Compound II) Single-crystal X-ray diffraction reveals that both hybrid compounds assemble into robust 3D supramolecular networks governed by extensive ionic charge-assisted (N-H & sdot;& sdot;& sdot;Cl, C-H & sdot;& sdot;& sdot;Cl) hydrogen bonds. Hirshfeld surface analysis demonstrates that H & sdot;& sdot;& sdot;Cl (up to 37.1) and H & sdot;& sdot;& sdot;H contacts dominate the crystal packing. Quantum theory of atoms in molecules (QTAIM), non-covalent interaction (NCI) calculations and Time-dependent DFT (TD-DFT) validate the purely non-covalent character of these lattice-stabilizing interactions. Single-beam Z-scan measurements under continuous-wave excitation show that both complexes exhibit strong reverse saturable absorption (RSA) and thermal self-defocusing behavior. Compound II demonstrates a significantly enhanced third-order susceptibility chi 3 = 1.899 & times; 10-5 compared to Compound I chi 3= 1.25 & times; 10-5 driven by efficient dication-to-halometalate electronic coupling and LMCT interactions. Furthermore, Compound I exhibited pronounced antibacterial efficacy against Escherichia coli 19 mm and S. aureus 21 mm while Compound II demonstrated superior cytotoxic potency against MDA-MB-231 triple-negative breast cancer cells with an IC50 of 10.96 mu g/mL (compared to 25.25 mu g/mL for Compound I). These results highlight the dual potential of compound I and II in photonic devices and as next-generation anti-cancer therapeutics.
