Scopus Research — Dakhil Nasser Taha

This study reports Darcy-Forchheimer stagnated flow confined by elongating surface. Nanofluid dynamics is scrutinized through Brownian movement and thermophoresis. Flow formulation features non-Newtonian rate type (Maxwell) material. Transportation expressions (i.e., energy and concentration) are modeled under varying conductivity, generalized heat-mass transference (i.e., Cattaneo-Christov (CC) dual diffusion theories) and varying diffusivity. The approach utilized in this investigation involves initially deriving the nonlinear PDEs (partial differential expressions) that govern the dynamics of flow along with heat-mass transference. Subsequently, these PDEs are transmuted into their corresponding ODEs (ordinary differential expressions) utilizing similarity variables. To compute these resulting ordinary differential expressions, a homotopic scheme is deployed. The solutions obtained for these ordinary differential expressions impart insights into deviations in non-dimensional quantities. These outcomes are visually represented through graphs and subjected to an inclusive analysis. The analytical outcomes are authenticated with a previously available limiting case and found exceptional agreement, confirming the precision and consistency of deployed analytic scheme. It is noticed that escalating relaxation-time factors yield a decay in temperature along with nano-particles concentration while opposite characteristics are reported for varying conductivity and diffusivity factors. © 2025 The Author(s)

This study investigated the designing of a simple and rapid flow injection (FI) system and the determination of Isoniazid in a prepared aqueous solution. The principle of the method depended on the indirect reaction of the isoniazid drug with copper(II)-neocuproine (Cu(II)-NCPR) complex after acidifying the aqueous medium. The yellow-orange and charge transfer complex had maximum absorption at 455 nm. The optimum conditions of the FIA were studied. The calibration graph of isoniazid was constructed with a linear range of 0.10 to 10.00 mg/L, and a linearity (r2) value of 0.9988. The detection and quantification limits were 0.073 and 0.221 mg/L, respectively. The molar absorptivity (ε) was 56.68×104 L/mol.cm and Sandell's sensitivity was 0.84 ×10-3 µg/cm. The manufactured local valve was characterized by inexpensive, easily running, high repeatability (n = 6) at an RSD of 2.18%, and the dead volume was zero. The dispersion coefficient values were 1.91, and 1.53 for both concentrations of 0.60, and 4.00 mg/L, respectively. The sampling rate of the analysis for the FIA system was 63.00 samples per hour. The proposed analytical flow injection method was successfully applied to standard aqueous solutions and tablets of isoniazid. © 2025 Chemical Society of Ethiopia and The Authors.

A low-cost and high throughput flow injection analysis (FIA) system design is conducted to determine Brilliant Green (BG) dye. The research includes studying the chemical and physical variables and control of optimal conditions of the FIA system. The merging zone technique uses a homemade flow injection valve to determine BG dye. The optimum conditions are studied, such as the flow rate of the carrier, optimal dye volume, repeatability, dead volume, and dispersion coefficient. The flow rate is 3.0 mL min-1, the optimal volume of dye is 82.425 μL, the repeatability is high for eight measurements (n = 8), and the values of dispersion coefficient are 1.41 and 1.44 for the concentrations of 4 and 7 mg L-1, respectively. The calibration graphs have linear ranges of (0.5 - 10) mg L-1 and (0.07 - 16) mg L-1, with detection limits of 0.413 and 0.068 mg L-1 for the spectrophotometric and FIA methods, respectively. The results obtained were statistically treated. FIA method successfully applied to standard solutions demonstrates its reliability and potential for further applications. © (2025), (University of Chemical Technology and Metallurgy). All rights reserved.

In this study, various machine learning (ML) algorithms have been applied to predict the melting temperature (Tm) of organic semiconductors. The study reveals that fr_allylic_oxide and VSA-Estate10 exhibit a high Pearson correlation with Tm. among the trained ML models, Random Forest (RF) and Gradient Boosting (GB) achieve a good R-Squared (R2) values of 0.89 and 0.78 with RMSE values of 6.37 and 14.61, respectively. Further analysis using SHAP values reveals that VSA_Estate2 and MolLogP are the most impactful features on model performance. Additionally, it is found that the synthetic accessibility (SA) of the semiconductors is up to 0.25 to highlight the need for balance between crystallinity and noncrystallinity. The t-Distributed Stochastic Neighbor Embedding (t-SNE) map of the dataset showed equal components to indicate a complex interplay between molecular features. The current study demonstrates the potential of ML in predicting Tm values and provides insights into the relationships between molecular structure and thermal properties of organic semiconductors. These findings have significant implications for the design and synthesis of organic electronic materials with tailored thermal properties. © Indian Association for the Cultivation of Science 2025.

A new study of the effect of a previously unstudied factor on dispersion, and repeatability of the injected sample. The design idea is based on manufacturing two new microcells with different volumes used in flow injection (FI) analysis systems and determining the measurements of the external structure, internal paths, and the measuring chamber with high accuracy. The efficiency of the FI system was tested by measuring the dead volume, and it was found to be zero. All measurements (n=5) were implemented by using the concentration 10.00 mg/L of Toluidine Blue dye solution at the wavelength 625.0 nm, flow cells with the volumes (35.0, 80.0, and 450.0) µL, sample volumes (39.25 and 78.50) µL, and flow rates (2.6, 4.5, and 6.6) mL/min. The results of the study indicate a relationship between flow cell volume and dispersion values. This relationship becomes apparent when other factors, such as sample volume and flow rate, are changed. © 2024, Taras Shevchenko National University of Kyiv. All rights reserved.

Ion exchange chromatography was created using a polymer-based monolithic column as a strong cation-exchange column with various function groups. Acrylic acid (A. acid), glycidyl methacrylate (GMA), and acryl amid were used to make monolithic columns via free radical polymerization (A. amid). The epoxy rings were then sulfonated at 70°C using Na2SO3. A model of common cation of Ni(II) spectrophotometry was used to assess the monolithic column, which was compared to atomic absorption approach. The LOD and LOQ were 0.001 g/mL and 0.002 g/mL, respectively, while the linearity (R2) was 0.9980. FTIR, Brunauer-Emmett-Teller (BET) analysis, and scanning electron microscopy were used to analyze the cation-exchange columns (SEM). © 2022 Wolters Kluwer Medknow Publications. All rights reserved.