Tribulus terrestris L. is a herb renowned for its abundance of saponins, flavonoids, and alkaloids, which are utilized in treating various health conditions. Protodioscin functions by enhancing the conversion of testosterone into potent dihydrotestosterone, stimulating an increase in libido, red blood cell production from the bone marrow, and muscle development. Contemporary ultrasound-assisted-extraction (UAE) process employing green extraction solvents was selected to design the required separation system. The experimental plan was developed based on the independent operating variables - extraction time, operating temperature and solvent system composition in order to determine the influence of defined parameters and their interactions on the extraction yield and the presence of protodioscin. The 3D-RSM approach was introduced to determine the optimal values of studied independent variables in the area of maximal extraction yield. UAE process performed at optimal operating conditions generated maximal extraction yield (31 %, w/w) and protodioscin content of 5.9 mg/g dry plant matrix. Experimental data was used to develop an ANN for the defined extraction system using the operating variables values as the input matrix and observed yield as target matrix. Successfully designed and trained ANN generated high correlation (r = 0.9992) between observed data and predictive model' outputs, and MSE value of 0.29107.

Refinery off-gas is one of the major causes of air pollution, where its reuse, through channeling into other plant setups to recover some of its constituent gases (via a steam reforming technique), is described as one of its best handling measures. A nominal off-gas containing 2.898% hydrogen (H2), 83.794% methane, 1.505% carbon dioxide, 1.103% nitrogen, 10.6% sulfur and 0.1% argon was fed to a plant to produce 37.52 kg of H2. To lift the performance of the multiple interconnected process units enhancing the generation of H2, temperature and pressure in the reactors were manipulated against the heat duty and H2 yield, where it was found that the two dependent variables are sensitive to changes made during Aspen Plus sensitivity analysis. Replacing some process units also shows significant improvement in the recovery of H2 gas. Adequate control of the synthesis process as exemplified in this work, will lead to smooth realization of the target end-product which is of high economic value; basically, looking at its potential for the manufacture of other useful materials it is already known for. Received: 10 May 2023 | Revised: 16 June 2023 | Accepted: 30 June 2023 Conflicts of Interest The authors declare that they have no conflicts of interest to this work. Data Availability Statement The data that supports the findings of this study is openly available with zannahabba154@gmail.com, and would be shared upon request via email.

Extraction and processing of polyether polyols derived from petrochemicals, commonly used as surfactants during polyurethane foam (PUF) production, contribute to carbon emissions and raises the issue of long-term sustainability given that petrochemicals are non-renewable resources. Here, 5 mg and 4 mg of neem seed oil are employed to form flexible and rigid PUF, classified purposefully based on their divergent usage. To find an environmentally friendly replacement, flexible PUF whose mass, volume, density, compression, tensile strength, cream time, foam rise and rising time are 0.0047 kg m3, 16.52 kg/m3, 8.10%, 39.28 kN/m2, 60s, 10s and 60s is formed by mixing 1.25 kg polyol, 5mg silicon oil and 10g calcium carbonate (CaCO3). Likewise, by mixing 1.2 kg polyol, 4mg silicon oil and 8g CaCO3, a rigid PUF with 0.005kg, m3, 16.2 kg/m3, 8.15%, 40.72 kN/m2, 50s, 15 cm and 58s key, physical and mechanical property as respectively listed under the flexible PUF formulation is produced. Both foams were produced using equal amounts of toluene diisocyanate, water, stannous octoate and methylene chloride, resulting in PUF that can be used in insulation, cushioning and construction support applications based on their characteristic height, density, tensile strength and compressive strength. As the surfactant, neem seed oil's potential in the synthesis of PUF cannot be overemphasized. The study of the kinetics of PUF production is limited and should trigger the adoption of biobased surfactants for industrial applications in the future.

In recent decades, due to the rapid development and application of wireless communication, flexible electronics, and smart devices, electromagnetic interference (EMI) and radiation pollution have been intensified, creating an urgent demand for efficient EMI shielding materials. Carbon nanostructures such as graphene and carbon nanotubes are considered promising candidates due to their excellent properties, such as high electrical conductivity, low density, large specific surface area, and flexibility. This work reports our recent results in the design and testing of polymer nanocomposites with irradiated hybrid carbon nanostructure (graphene/multi-walled carbon nanotubes) used as EMI shielding materials. Five representative composites with varying filler loadings (AH of 15% and AM1 of 20 wt%), thicknesses (0.208–0.48 mm), and e-beam irradiation doses (from 50 to 400 kGy) were systematically characterized using SEM, FTIR, TGA/DSC, and vector network analyzer (VNA) measurements in the S-band (2.65–3.90 GHz). The effects of different e-beam irradiation doses and hybrid carbon contents on conductive network construction, interface engineering, and porous or layered structures on EMI shielding performance are discussed. Experimental results show that all studied composites exhibited strong absorption-dominant behavior (SE_A), while the multiple reflection component (SE_M) was found to be negligible. Both filler loading and sample thickness significantly enhanced shielding performance, with a pronounced synergistic interaction observed between these parameters. A quadratic Response Surface Methodology (RSM) model was developed to correlate the total shielding effectiveness (SE_T) with thickness and filler content, yielding high predictive accuracy (R² > 0.96). The model enables efficient optimization of composite design for targeted shielding levels.

Hexavalent chromium is a toxic form of chromium that has significant health and environmental implications. Reducing hexavalent chromium to trivalent chromium is a crucial step in immobilizing and removing Cr(VI) from water resources. Nano zero-valent iron (nZVI) as an electron-donating agent was used for Cr(VI) reduction in aqueous solution. The effect of contact time and initial concentration of nano zero-valent iron on Cr(VI) reduction was studied. The process of Cr(VI) reduction was designed and optimized using response surface methodology. The results indicated an enhancement in the Cr(VI) reduction ratio with increasing initial concentration of nano zero-valent iron and contact time. A second-order polynomial equation was used to model the correlation between the independent and dependent variables. The utilized model effectively predicted the response variable based on the input variables with a high coefficient of determination (R2) of 0.9475 and a correlation coefficient (R) of 0.9734. Additionally, the accuracy of the fitted model was demonstrated by the low values of the mean squared error (MSE) at 0.04315 and the sum of squared errors (SSE) at 0.06562. The optimal conditions for reducing Cr(VI) in aqueous solution using nano zero-valent iron were determined to be an initial nZVI concentration of 15 mg/L and a contact time of 209 min.